CSLB Landscaping (C-27) Trade — All Questions

A rotor sprinkler head throwing water 30 feet is BEST described as which type of irrigation component?

• a.A micro-spray for shrub beds
• b.A gear-driven rotor for large turf areas✓
• c.A drip emitter for point-source watering
• d.A bubbler for tree wells

Gear-driven rotors rotate a single stream back and forth and are designed for large open turf areas because of their long throw radius, typically 25 to 50 feet. Drip emitters, micro-sprays, and bubblers all deliver water at much shorter ranges for beds, shrubs, or trees.

Precipitation rate for a sprinkler zone is calculated using which formula?

• a.PR = area / (96.3 x GPM)
• b.PR = (96.3 x GPM) / area✓
• c.PR = PSI x GPM / 96.3
• d.PR = GPM x 60 x area

Precipitation rate in inches per hour equals 96.3 times the total GPM applied divided by the area in square feet covered by the heads. The constant 96.3 converts gallons per minute over square feet into inches per hour. This tells the designer how fast water is being applied so it can be matched to soil intake.

A zone has four heads each using 3 GPM covering a total area of 400 square feet. What is the approximate precipitation rate?

• a.About 2.9 inches per hour✓
• b.About 12 inches per hour
• c.About 0.03 inches per hour
• d.About 0.5 inches per hour

Total flow is 4 heads times 3 GPM equals 12 GPM. Using PR = 96.3 x 12 / 400, you get 1155.6 / 400, which is about 2.89 inches per hour. Rounding gives approximately 2.9 inches per hour.

Under California's MWELO (23 CCR §493.2.2), overhead irrigation is not permitted within what distance of any non-permeable surface?

• a.Within 12 inches
• b.Within 36 inches
• c.Within 18 inches
• d.Within 24 inches✓

Section 493.2.2(d)(10) provides that overhead irrigation shall not be permitted within 24 inches of any non-pervious surface. Drip or other low flow non-spray technology may be used inside that setback, and the setback may be planted or unplanted and surfaced with mulch, gravel, or other porous material. The requirement may be modified where no runoff occurs, where the adjacent hardscape drains entirely to landscaping, or where the designer demonstrates an alternative design preventing water waste. This is a setback from hardscape, not a limit on how narrow a planting area may be — the width rule is a separate provision at 10 feet.23 CCR §493.2.2(d)(10)

A reduced pressure principle (RP) backflow assembly is primarily used to protect a potable water supply against what?

• a.Both backsiphonage and backpressure hazards✓
• b.Freezing temperatures in the water supply line
• c.Excess flow velocity through the meter
• d.Low incoming water pressure only

An RP assembly is the highest level of mechanical backflow protection and guards against both backsiphonage and backpressure, making it suitable for high-hazard cross-connections. Irrigation systems using fertilizer or chemical injection are considered high hazard and typically require an RP device. It uses two check valves and a relief valve between them.

A pressure vacuum breaker (PVB) must be installed at what minimum height relative to the highest downstream sprinkler head or outlet?

• a.6 inches above the highest head
• b.12 inches above the highest head✓
• c.At the same level as the heads
• d.36 inches below grade

A pressure vacuum breaker must be installed at least 12 inches above the highest downstream outlet or sprinkler head so atmospheric venting works correctly against backsiphonage. It protects against backsiphonage only, not backpressure. Correct elevation is essential for the device to function.

An atmospheric vacuum breaker (AVB) has which key installation limitation?

• a.It protects against backpressure as well
• b.It requires two independent check valves
• c.It cannot be under continuous pressure✓
• d.It may be installed below the sprinkler heads

An atmospheric vacuum breaker protects only against backsiphonage and must be installed downstream of the last control valve with no shutoff valves after it. It cannot be under continuous pressure for more than about 12 hours and must sit above downstream outlets. It is the simplest and least expensive backflow device.

Water hammer in an irrigation system is BEST reduced by which measure?

• a.Removing all valves from the mainline
• b.Raising velocity above 10 feet per second
• c.Keeping velocity below about 5 feet per second✓
• d.Using undersized pipe on long runs

Water hammer is a pressure surge caused by fast-moving water stopping abruptly, often from quick-closing valves. Keeping design velocity at or below about 5 feet per second and using slow-closing solenoid valves reduces the surge. Oversized surges can burst pipe and fittings over time.

Which pipe material is MOST commonly used for buried irrigation mainlines under constant pressure in California?

• a.Galvanized steel with threaded joints
• b.Corrugated black flexible tubing
• c.Schedule 40 PVC rated for constant pressure✓
• d.Thin-wall aluminum tube and fittings

Buried pressure mainlines are commonly run in Schedule 40 PVC or an appropriate pressure-rated class of PVC because it handles constant pressure and resists corrosion. Lateral lines downstream of valves may use lighter class PVC since they are only pressurized during operation. Corrugated tubing is used for drainage, not pressurized supply.

As irrigation pipe diameter decreases while flow stays the same, what happens to friction (pressure) loss?

• a.Friction loss stays the same
• b.Friction loss becomes zero
• c.Friction loss decreases
• d.Friction loss increases✓

For a given flow rate, a smaller pipe forces water to move faster, and higher velocity dramatically increases friction loss along the pipe. This is why undersized pipe starves distant heads of pressure. Designers size pipe to keep velocity and friction loss within acceptable limits.

A drip emitter rated at 1 GPH means it delivers approximately how much water per hour?

• a.1 gallon per hour✓
• b.1 gallon per minute
• c.1 quart per day
• d.60 gallons per hour

GPH stands for gallons per hour, so a 1 GPH emitter releases one gallon over a full hour of operation. Drip systems are rated in gallons per hour because they apply water slowly and precisely at the root zone. This low, slow application reduces runoff and evaporation.

Distribution uniformity (DU) in an irrigation audit measures what?

• a.The total gallons of water used per month
• b.How evenly water is applied across the area✓
• c.The pressure rating of the pipe used
• d.The color and density of the turf

Distribution uniformity describes how evenly water is spread across a zone, comparing the driest areas to the average application. Higher DU means less water waste because you do not have to over-irrigate to compensate for dry spots. Poor uniformity commonly comes from mismatched heads, wrong spacing, or pressure problems.

Head-to-head spacing of spray heads means each head is spaced so its throw reaches what point?

• a.Only the center of the zone
• b.The base of the adjacent head✓
• c.Halfway to the next head
• d.Twice the distance to the next head

Head-to-head coverage, also called 100 percent overlap, spaces heads so each one throws water all the way to the adjacent head. Because spray heads apply less water at the outer edge of their radius, this overlap is required for even coverage. Spacing heads farther apart creates dry rings and poor uniformity.

A zone must deliver 18 GPM and the water meter supplies 12 GPM available flow. What is the BEST corrective action?

• a.Increase system pressure to 120 PSI
• b.Remove the backflow device
• c.Run all heads longer
• d.Split the zone into two smaller zones✓

When a zone's demand exceeds available flow, heads will not operate at their designed pressure and coverage suffers. Splitting the zone into two zones that each stay within the 12 GPM supply solves the problem. Raising pressure cannot create flow the meter cannot deliver, and removing the backflow device is unsafe and illegal.

A matched precipitation rate (MPR) nozzle set is designed to do what?

• a.Eliminate the need for a controller
• b.Increase the operating pressure at each head
• c.Reduce the number of valves needed
• d.Apply water at the same rate for any arc✓

Matched precipitation rate nozzles apply the same depth of water per hour whether the head covers a quarter, half, or full circle. Manufacturers scale each nozzle's flow to its arc so a quarter head uses about one-fourth the flow of a full head. This keeps the whole zone evenly watered on a single run time.

A smart irrigation controller that adjusts run times using local weather data is called what?

• a.An ET-based or weather-based controller✓
• b.A pressure-regulating master valve
• c.A manual mechanical dial timer
• d.An anti-siphon irrigation valve

An evapotranspiration (ET) or weather-based controller uses temperature, humidity, wind, and solar data to estimate plant water needs and adjust schedules automatically. This reduces overwatering compared with a fixed manual timer. MWELO encourages such controllers to improve landscape water efficiency.

A pressure-regulating device is added to a spray head when static pressure is too high. What is the typical target operating pressure for fixed spray heads?

• a.About 60 to 70 PSI
• b.About 100 PSI
• c.About 5 PSI
• d.About 30 PSI✓

Fixed spray heads are designed to operate near 30 PSI; much higher pressure causes misting and fogging that drifts away and wastes water. Pressure-regulating heads or in-line regulators bring high static pressure down to the efficient range. Rotors generally run at higher pressures than sprays.

Misting or fogging from spray heads is usually a sign of what condition?

• a.Broken lateral line
• b.Clogged emitters
• c.Pressure too high✓
• d.Pressure too low

When operating pressure is too high, the water leaves the nozzle atomized into a fine mist that drifts and evaporates instead of landing on the target area. The fix is to install pressure regulation so heads run at their rated pressure. Low pressure causes the opposite problem, poor throw and doughnut patterns.

An irrigation solenoid valve is operated by what signal from the controller?

• a.A low-voltage 24-volt AC signal✓
• b.A mechanical cable pull from the timer
• c.Line power at 240 volts AC
• d.A pneumatic air pressure signal

Standard automatic irrigation valves use a 24-volt AC solenoid that the controller energizes to open the valve. When the controller sends the low-voltage signal, the solenoid lifts a plunger and hydraulic pressure opens the diaphragm. This low voltage is safer and easier to run underground than line voltage.

Under MWELO, the Maximum Applied Water Allowance (MAWA) is based primarily on which factors?

• a.Only the total number of sprinkler heads
• b.Pipe diameter, valve count, and head spacing
• c.The brand of controller that is installed
• d.Reference ET, area, and adjustment factor✓

MAWA sets a water budget calculated from the local reference evapotranspiration (ETo), the landscape area, and an ET adjustment factor that reflects allowed plant water use. The designed landscape's estimated water use must stay within this allowance. This is the core water-budget concept of MWELO.CA MWELO (Title 23)

Subsurface drip irrigation is especially useful in which situation?

• a.Cooling a paved patio surface in the summer
• b.Filling a decorative garden pond
• c.Watering a steep concrete slope face
• d.Slopes and narrow strips prone to runoff✓

Subsurface drip places emitter tubing below the soil surface, delivering water directly to roots with virtually no overspray or runoff. This makes it well suited for slopes and narrow strips where spray irrigation would waste water on pavement. It also reduces evaporation and weed germination at the surface.

Cycling a station into several short run times instead of one long run is called cycle-and-soak and mainly prevents what?

• a.Freezing pipes in cold weather
• b.Clogged spray nozzles and inline filters
• c.Runoff on slow-draining soils and slopes✓
• d.Low water pressure at the heads

Cycle-and-soak breaks a long irrigation into shorter bursts with soak periods between, letting water infiltrate before more is applied. This prevents runoff when the precipitation rate exceeds the soil's intake rate, common on clay soils and slopes. It improves efficiency without changing total water applied.

A flow sensor connected to a smart controller is MOST useful for detecting what problem?

• a.A broken lateral line or stuck valve✓
• b.A sudden change in air temperature outdoors
• c.The color and density of the turf
• d.The pH level of the surrounding soil

A flow sensor measures real-time water flow and lets the controller compare it to expected values for each zone. Abnormally high flow signals a broken pipe or stuck-open valve, and the controller can shut the system down to prevent water loss. This protects against costly leaks and water waste.

To convert a flow of 12 GPM to gallons per hour for scheduling, what is the result?

• a.720 gallons per hour✓
• b.120 gallons per hour
• c.200 gallons per hour
• d.12 gallons per hour

There are 60 minutes in an hour, so 12 gallons per minute times 60 equals 720 gallons per hour. Converting GPM to GPH is useful when comparing zone flow to an hourly water budget. This simple multiplication helps estimate total water use.

A rain sensor or rain shutoff device connected to a controller does what?

• a.It increases run time during storms
• b.It measures the soil pH in the bed
• c.It boosts the water pressure at the heads
• d.It suspends irrigation after enough rainfall✓

A rain sensor interrupts the controller's watering cycle once it detects a set amount of rainfall, preventing irrigation during and shortly after storms. This avoids the waste of watering an already-wet landscape. Many California water agencies require or encourage rain shutoff devices on new systems.

A soil that drains very quickly, warms fast, and holds little water is MOST likely which texture?

• a.Sandy soil✓
• b.Silt
• c.Peat
• d.Clay

Sandy soils have large particles with large pore spaces, so water drains through rapidly and little is retained. They warm quickly in spring but dry out fast and need more frequent irrigation. Adding organic matter improves their water and nutrient holding capacity.

Most landscape and turf plants grow best in soil with a pH in which range?

• a.About 3.0 to 4.0 (strongly acidic)
• b.About 9.0 to 10.0 (strongly alkaline)
• c.Exactly 8.5 in all landscape soils
• d.About 6.0 to 7.0 (slightly acidic)✓

A slightly acidic to neutral pH of roughly 6.0 to 7.0 keeps most nutrients available for uptake by common landscape plants and turf. Extremely acidic or alkaline soils lock up nutrients even when they are present. Acid-loving plants like azaleas prefer the lower end of this range.

To lower the pH of an alkaline soil, which amendment is commonly used?

• a.Agricultural lime
• b.Elemental sulfur✓
• c.Gypsum for pH change
• d.Wood ash

Elemental sulfur is oxidized by soil bacteria into sulfuric acid, gradually lowering soil pH over weeks to months. Lime and wood ash raise pH, and gypsum changes soil structure and adds calcium without significantly changing pH. Sulfur is the standard choice to acidify alkaline soils.

In a fertilizer labeled 16-6-8, the three numbers represent the percentage of which nutrients in order?

• a.Phosphorus, nitrogen, potassium
• b.Potassium, phosphorus, nitrogen
• c.Nitrogen, phosphorus, potassium✓
• d.Nitrogen, potassium, phosphorus

The three-number N-P-K label always lists nitrogen first, phosphorus (as P2O5) second, and potassium (as K2O) third. So 16-6-8 is 16 percent nitrogen, 6 percent phosphorus, and 8 percent potassium by weight. Nitrogen drives leafy green growth, phosphorus supports roots and flowers, and potassium aids overall vigor.

A 50-pound bag of 20-0-10 fertilizer contains how many pounds of actual nitrogen?

• a.1 pound
• b.20 pounds
• c.5 pounds
• d.10 pounds✓

Actual nitrogen equals the bag weight times the nitrogen percentage, so 50 pounds times 0.20 equals 10 pounds of nitrogen. Landscapers use this calculation to apply the correct pounds of nitrogen per 1,000 square feet. Knowing actual nutrient content prevents over- or under-application.

Applying a 3-inch layer of organic mulch around plants primarily provides what benefits?

• a.It increases soil compaction around the roots
• b.It eliminates all irrigation needs
• c.It conserves moisture and suppresses weeds✓
• d.It raises soil pH sharply within days

A layer of organic mulch reduces evaporation, keeps soil temperatures more stable, and blocks light that weed seeds need to germinate. As it decomposes it also adds organic matter to the soil. Mulch is one of the most cost-effective water-saving practices in landscaping.

When planting a container-grown shrub, the top of the root ball should be placed at what level relative to the surrounding soil?

• a.6 inches below grade
• b.Buried under 4 inches of soil over the crown
• c.At or slightly above the surrounding grade✓
• d.12 inches below grade

The top of the root ball should sit at or slightly above finished grade so the crown does not sit in water and settle too deeply. Planting too deep suffocates roots and can rot the crown or trunk. Slightly high planting allows for minor settling while keeping the crown dry.

Gypsum is added to certain clay soils primarily to accomplish what?

• a.It lowers the soil pH significantly
• b.It kills weed seeds already in the bed
• c.It displaces sodium and improves structure✓
• d.It adds a large amount of nitrogen

Gypsum, calcium sulfate, supplies calcium that replaces sodium in sodic clay soils, improving aggregation and water penetration. It changes soil structure and drainage without appreciably altering pH. It is not a fertilizer and does not add nitrogen.

A newly planted tree needs staking. What is the correct staking practice?

• a.Wrap wire tightly around the bark
• b.Allow movement and remove stakes in a year✓
• c.Tie the trunk rigidly for at least five years
• d.Drive one stake straight through the root ball

Stakes should support the tree while allowing slight trunk movement, which encourages a stronger trunk and root system. Ties should be loose and use a broad, soft material, and stakes are typically removed after about one growing season. Rigid staking and bare wire damage the tree and create a weak, dependent trunk.

Which practice BEST improves drainage in a heavy clay planting bed?

• a.Compact the soil before planting
• b.Line the bottom of the bed with plastic sheeting
• c.Add fine sand only in small amounts
• d.Incorporate organic matter such as compost and improve grading✓

Blending compost and other organic matter into clay improves aggregation, creating larger pore spaces that let water move through. Combined with grading that directs excess water away, this relieves waterlogging. A small amount of sand can actually make clay worse by forming a concrete-like mix, and plastic traps water.

Proper plant spacing at installation should be based on what?

• a.The size of the nursery container only
• b.Fitting as many plants as possible
• c.The mature size and spread of the plant✓
• d.The current size of the plant

Plants should be spaced according to their expected mature width so they fill in without overcrowding. Spacing based on current small size leads to crowding, poor air circulation, and disease as plants grow. Good spacing reduces long-term maintenance and pruning.

A soil amendment high in nitrogen but low in decomposition, like fresh wood chips tilled into soil, can cause what short-term problem?

• a.A large and rapid rise in soil pH
• b.Temporary nitrogen deficiency, or drawdown✓
• c.Excess nitrogen that burns the plants
• d.Immediate salt toxicity in the root zone

When high-carbon materials like fresh wood chips are mixed into soil, microbes decomposing them consume available nitrogen, temporarily starving plants of it. This nitrogen drawdown causes yellowing until decomposition slows. Using wood chips as surface mulch instead of tilling them in avoids the problem.

Cool-season turfgrasses such as tall fescue grow most actively in which conditions?

• a.Deep winter freezes only
• b.Cooler spring and fall temperatures✓
• c.Complete shade year round
• d.The hottest summer weeks

Cool-season grasses like tall fescue peak in growth during the cooler temperatures of spring and fall and slow down in summer heat. Warm-season grasses such as Bermuda are the opposite, thriving in summer. Choosing the right type for the climate reduces water and maintenance needs.

When establishing turf from seed, keeping the seedbed consistently moist is important because what?

• a.Water is needed only after sprouts appear
• b.Seeds germinate better when completely dry
• c.Germinating seeds and shallow roots die quickly✓
• d.Moisture prevents any weed growth at all

Germinating seeds and their tiny first roots sit near the surface and die rapidly if the seedbed dries out. Light, frequent watering keeps the top layer moist until seedlings establish deeper roots. Once established, watering shifts to deeper and less frequent cycles.

Rough grading followed by finish grading before planting is done primarily to accomplish what?

• a.To create low spots that hold water
• b.To increase soil compaction before planting
• c.To set surface drainage and a smooth planting bed✓
• d.To remove all topsoil from the site

Grading shapes the soil surface so water drains away from structures and toward intended outlets, and finish grading creates a smooth, even bed for planting or turf. Poor grading causes ponding, erosion, and drainage complaints. Positive slope away from buildings is a core goal.

Compost is added to soil primarily to do what?

• a.To improve structure and add organic matter✓
• b.To compact the soil around new plants
• c.To serve as the only nutrient source
• d.To raise pH to strongly alkaline levels

Compost improves soil structure, increases water and nutrient holding capacity, and feeds beneficial soil microorganisms. While it adds some nutrients, its main value is as an organic amendment that improves overall soil health. It benefits both sandy and clay soils.

Which plant selection strategy BEST supports water-efficient landscaping in California?

• a.Drought-tolerant plants grouped by water need✓
• b.Mixing high- and low-water plants on one valve
• c.Select plants at random from the nursery
• d.Plant only high-water tropical species

Selecting drought-tolerant, climate-appropriate plants and grouping them by similar water needs, called hydrozoning, lets each irrigation zone be scheduled efficiently. Mixing high- and low-water plants on one valve forces overwatering of the low-water plants. Hydrozoning is a core MWELO efficiency practice.

A soil test reports very low phosphorus. Which fertilizer analysis would BEST correct it?

• a.21-0-0
• b.46-0-0
• c.0-0-60
• d.0-45-0✓

The middle number of the N-P-K label is phosphorus, so 0-45-0 supplies a high level of phosphorus and nothing else. 21-0-0 and 46-0-0 supply only nitrogen, and 0-0-60 supplies only potassium. Matching the deficient nutrient to the fertilizer analysis avoids waste.

Balled-and-burlapped (B&B) trees should have synthetic burlap and wire baskets handled how at planting?

• a.Removed only after two full growing seasons
• b.Left fully intact around the entire root ball
• c.Never touched once the tree is set
• d.Loosened and folded down, synthetics removed✓

Natural burlap decomposes, but synthetic burlap and twine do not and can girdle roots, so they should be removed or at least peeled back from the top of the root ball. Wire baskets are cut and folded down after the tree is set. This lets roots grow outward into the surrounding soil.

Slow-release (controlled-release) fertilizers are advantageous because they do what?

• a.They release all their nutrients in one day
• b.They contain no nitrogen or potassium
• c.They feed gradually, cutting burn and leaching✓
• d.They only work below freezing temperatures

Controlled-release fertilizers meter nutrients out over weeks or months, lowering the risk of fertilizer burn and reducing nutrient leaching into groundwater. This gives steadier plant growth and fewer applications. They are especially useful for sandy soils where quick-release nutrients leach fast.

The planting hole for a balled tree should generally be dug how wide relative to the root ball?

• a.Ten times the width and twice as deep
• b.The same width but twice as deep as the ball
• c.Two to three times the width of the ball✓
• d.Half the width of the root ball

A hole two to three times as wide as the root ball loosens surrounding soil so new roots spread outward easily, while keeping depth equal to the ball prevents settling and deep planting. Digging deeper than the ball causes the tree to sink and the crown to sit too low. Wide and shallow is the standard rule.

Salt buildup in soil from irrigation water or fertilizer is BEST managed by what practice?

• a.Deep irrigation to leach salts downward✓
• b.Adding more fertilizer to the planting bed
• c.Compacting the soil surface very firmly
• d.Reducing all watering to zero for a month

Applying a deep, thorough irrigation, called leaching, dissolves accumulated salts and carries them downward below the root zone where they no longer harm plants. This requires soil with adequate drainage. Adding more fertilizer would worsen the salt problem.

Finished grade around a building should slope away from the foundation at approximately what minimum for the first several feet?

• a.Sloping the grade back toward the building
• b.About 5 percent, or 6 inches over 10 feet✓
• c.Flat, with no slope in any direction
• d.A 45-degree drop at the foundation

A common standard is to slope soil away from a foundation about 6 inches over the first 10 feet, roughly a 5 percent grade, to carry surface water away from the structure. Sloping toward the building or leaving it flat allows water to pond against the foundation. Positive drainage protects the structure from moisture damage.

A French drain is BEST described as what?

• a.A raised planter box built along the wall
• b.A surface concrete drainage channel or swale
• c.A type of segmental retaining wall
• d.A gravel-filled trench with perforated pipe✓

A French drain is a trench filled with gravel around a perforated pipe that intercepts subsurface and surface water and carries it to a discharge point. Water enters the pipe through the perforations and flows by gravity away from the problem area. It is used to relieve soggy soils and protect foundations.

Before placing concrete pavers on a driveway, a compacted aggregate base is installed mainly to do what?

• a.A stable, load-bearing, well-draining foundation✓
• b.The final wearing surface of the driveway
• c.A replacement for perimeter edge restraints
• d.Added color and texture at the paved surface

A compacted crushed-aggregate base spreads loads, resists settling, and drains water away from the pavers, forming the structural foundation of the pavement. Without proper base compaction, pavers rut and settle unevenly. A sand setting bed and edge restraints are added on top of this base.

Aggregate base under hardscape is best compacted in what manner?

• a.Only after the pavers have been placed
• b.In thin lifts, each compacted before the next✓
• c.By soaking it thoroughly with water only
• d.In one thick lift with no compaction at all

Base material should be placed and compacted in thin lifts, commonly around 3 to 4 inches, so the compactor can achieve full density throughout. Compacting one thick lift leaves the lower portion loose, causing later settlement. Layered compaction produces a stable, uniform base.

A segmental retaining wall over a certain height typically requires what to prevent failure?

• a.Engineered design, drainage, and geogrid✓
• b.No drainage of any kind behind the wall
• c.Only a decorative facing on the wall front
• d.A smooth clay backfill packed tight

Taller retaining walls carry large lateral soil loads and usually require engineered design, gravel backfill with a drain to relieve water pressure, and geogrid soil reinforcement. Without drainage, water pressure builds behind the wall and pushes it over. Many jurisdictions require permits and engineering above a set height, commonly 3 to 4 feet.

Weep holes or a drainage system behind a retaining wall serve what purpose?

• a.To relieve hydrostatic pressure behind the wall✓
• b.To hold more water in the backfill zone
• c.To increase the soil pressure on the wall
• d.To add decorative accents to the wall face

Weep holes and gravel drains allow water that collects behind a wall to drain out, relieving hydrostatic pressure that would otherwise push the wall over. Saturated soil greatly increases the load on a wall. Proper drainage is one of the most important factors in wall longevity.

A slope is described as 4:1. What does this mean?

• a.A 40 percent grade down the bank
• b.A vertical cliff with no run at all
• c.4 feet of run for every 1 foot of rise✓
• d.4 feet of rise for each 1 foot of run

A 4:1 slope means 4 units of horizontal distance for every 1 unit of vertical change, a gentle 25 percent grade. The first number is run and the second is rise in this common landscaping convention. Flatter ratios like 4:1 are more stable and easier to mow than steep ones like 2:1.

Managing stormwater runoff on a site with a bioswale accomplishes what?

• a.Slows runoff, filters pollutants, and promotes infiltration✓
• b.Prevents any water from infiltrating
• c.Raises the water table intentionally
• d.Concentrates runoff into a single fast channel

A bioswale is a shallow, vegetated channel that slows stormwater, filters out sediment and pollutants, and encourages water to soak into the ground. This reduces peak runoff and improves water quality leaving the site. Such low-impact designs are increasingly required for stormwater management.

A concrete slab for a patio typically includes control joints. What is their function?

• a.Planned weak points so cracks follow the joint✓
• b.Eliminating the need for a compacted stone base
• c.Increasing the water content of the slab
• d.Adding decorative color to the surface

Control joints are grooved or cut lines that create a deliberate weak plane, so as concrete shrinks and cracks, the cracks form neatly along the joint rather than randomly across the slab. They are usually spaced in feet roughly equal to two to three times the slab thickness in inches. They control, not eliminate, cracking.

Edge restraints installed around a paver patio serve what main purpose?

• a.To replace the compacted gravel base layer
• b.To keep pavers from spreading outward over time✓
• c.To change the color of the paver surface
• d.To provide seating around the patio edge

Edge restraints lock the perimeter pavers in place so the field of pavers cannot creep or spread apart under traffic. Without them, edges migrate and joints open up, leading to failure. They are a small but essential part of a durable paver installation.

A paved surface should be sloped for drainage at about what minimum cross slope?

• a.0 percent (dead level)
• b.10 to 15 percent
• c.Sloped toward the house
• d.About 1 to 2 percent✓

Paved surfaces such as patios and walkways are typically sloped about 1 to 2 percent, roughly 1/8 to 1/4 inch per foot, to shed water without being noticeably tilted. A dead-level surface ponds water, while too steep a slope is uncomfortable and unsafe. Water should always be directed away from structures.

A catch basin connected to underground drain pipe is used to do what?

• a.Collect surface water and pipe it away✓
• b.Store irrigation water for later reuse
• c.Support the base of a retaining wall
• d.Filter drinking water before use

A catch basin is a boxed inlet set at a low point that collects surface runoff and channels it into buried drain pipe leading to a safe discharge. A grate on top keeps out leaves and debris. It is a key part of a yard drainage system that prevents ponding.

When laying out a site from a plan, a builder's level or laser level is used primarily to establish what?

• a.Plant spacing across the planting beds
• b.Consistent elevations and grades✓
• c.Soil pH in the planting areas
• d.Water pressure at the meter

A builder's level, transit, or rotary laser establishes accurate reference elevations so grades, slopes, and drainage can be set consistently across a site. This ensures the finished landscape drains correctly and matches the plan. Accurate layout prevents costly grading errors.

Compaction of subgrade soil before hardscape is measured against what standard reference?

• a.A percentage of maximum dry density✓
• b.The number of compactor passes only
• c.The measured pH of the subgrade soil
• d.The color of the compacted soil

Compaction is specified as a percentage of a soil's maximum dry density determined by a laboratory Proctor test, commonly 90 to 95 percent for hardscape subgrade. Field testing verifies the soil reaches the required density. Adequate compaction prevents future settlement under pavement.

On expansive clay soils, hardscape and foundations are at risk because the soil does what?

• a.Stays perfectly stable in all conditions
• b.Turns to sand over time
• c.Swells when wet and shrinks when dry, causing movement✓
• d.Never holds water

Expansive clays contain minerals that absorb water and swell, then shrink as they dry, producing repeated ground movement that cracks slabs and walls. Managing moisture and using proper base and drainage details reduces this movement. Severe cases may need engineered foundations.

A dry-stack (mortarless) segmental block wall relies on what for stability?

• a.Steel beams set behind the block face
• b.A mortared concrete cap along the top
• c.Mortar placed between every block course
• d.Interlock, batter, and gravel backfill✓

Mortarless segmental walls gain stability from the interlocking block design, a slight backward lean (batter or setback), free-draining gravel backfill, and geogrid reinforcement layers in taller walls. There is no mortar, so drainage and reinforcement carry the loads. Proper base preparation is also critical.

Directing a downspout's discharge onto a splash block or into a pipe that carries it away from the house prevents what?

• a.Better interlock between the patio pavers
• b.A higher soil pH near the foundation
• c.Faster plant growth beside the house
• d.Erosion and ponding at the foundation✓

Concentrated roof runoff from a downspout can erode soil and saturate the ground against a foundation, leading to settlement and moisture intrusion. A splash block or piped extension moves that water away from the structure. This is a basic but important part of site drainage design.

Permeable pavers differ from standard pavers because they do what?

• a.They require no base course at all
• b.They are decorative only, not structural
• c.They block all water from passing through them
• d.They let stormwater soak through the joints✓

Permeable pavers are set with open, aggregate-filled joints over an open-graded stone base so rainwater infiltrates rather than running off. This reduces runoff volume and helps recharge groundwater, supporting stormwater regulations. They require a specially designed base to store and drain the water.

On a steep planted slope, which practice BEST controls erosion during establishment?

• a.Leaving the slope soil bare and exposed
• b.Frequent heavy flood irrigation
• c.Smooth compaction with no plants
• d.Blankets, mulch, and quick groundcover✓

Covering a slope with erosion-control blankets or netting, mulch, and fast-establishing groundcover protects the soil surface from rain impact and runoff until roots hold it. Bare or heavily flooded slopes erode and rill quickly. Vegetation and surface protection together stabilize the slope.

A retaining wall's footing or leveling pad should be placed on what?

• a.A layer of dry leaves and loose topsoil
• b.Compacted, level base at the proper depth✓
• c.Loose topsoil raked out smooth
• d.A single row of bricks laid flat

The base or leveling pad of a retaining wall must rest on compacted, level base material set at the correct depth so the wall does not settle or lean. A poor base is a leading cause of wall failure. Getting the first course level and solid is essential for the whole wall.

How many cubic yards of soil are needed to cover a 30 ft by 18 ft bed 6 inches deep?

• a.About 5 cubic yards
• b.About 2 cubic yards
• c.About 10 cubic yards✓
• d.About 20 cubic yards

Volume in cubic yards equals length times width times depth in feet divided by 27. Here 30 x 18 x 0.5 equals 270 cubic feet, divided by 27 equals 10 cubic yards. Six inches must be converted to 0.5 feet before calculating.

The formula for calculating cubic yards of bulk material for a rectangular area is which of the following?

• a.Length plus Width plus Depth
• b.Length x Width x Depth divided by 12
• c.Length x Width divided by 27
• d.Length x Width x Depth (all in feet) divided by 27✓

Because a cubic yard contains 27 cubic feet (3 x 3 x 3), you compute the volume in cubic feet and divide by 27 to get cubic yards. All three dimensions must be in feet, so inches of depth are converted first. This formula applies to soil, mulch, gravel, and concrete.

A mulch supplier sells by the cubic yard. To mulch 900 square feet at 3 inches deep, how many cubic yards are required?

• a.About 2.8 cubic yards
• b.About 5 cubic yards
• c.About 27 cubic yards
• d.About 8.3 cubic yards✓

Convert 3 inches to 0.25 feet, then 900 x 0.25 equals 225 cubic feet, divided by 27 equals about 8.3 cubic yards. Always convert the depth to feet before dividing by 27. Ordering the right amount avoids extra delivery trips.

To find the area of a circular planting bed with a 20-foot diameter, which calculation is correct?

• a.3.14 x 20 (about 63 square feet)
• b.2 x 3.14 x 10 (about 63 square feet)
• c.20 x 20 (about 400 square feet)
• d.3.14 x 10 x 10 (about 314 square feet)✓

Circle area equals pi times the radius squared, and the radius is half the diameter, so 10 feet. Thus 3.14 x 10 x 10 equals about 314 square feet. Using diameter instead of radius is a common estimating error.

A landscape plan uses a scale of 1 inch = 10 feet. A bed measures 4 inches long on the plan. What is its actual length?

• a.40 feet✓
• b.14 feet
• c.400 feet
• d.4 feet

At a scale of 1 inch equals 10 feet, you multiply the drawing measurement by 10 to get the real dimension. So 4 inches times 10 feet equals 40 feet. Reading scale correctly is essential for accurate takeoffs from plans.

A patio is 12 ft by 15 ft and will be poured 4 inches thick. How many cubic yards of concrete are needed (before waste)?

• a.About 0.7 cubic yards
• b.About 15 cubic yards
• c.About 2.2 cubic yards✓
• d.About 6.7 cubic yards

Convert 4 inches to 0.333 feet, then 12 x 15 x 0.333 equals about 60 cubic feet, divided by 27 equals about 2.2 cubic yards. Contractors often add roughly 5 to 10 percent for waste and spillage. Ordering slightly extra avoids a short pour.

When estimating a job, which cost category covers wages, taxes, and workers' compensation for crew hours?

• a.Permit fees
• b.Labor cost✓
• c.Material cost
• d.Equipment rental

Labor cost includes crew wages plus payroll burdens such as payroll taxes and workers' compensation insurance. Estimators calculate labor from the hours a task takes multiplied by a fully burdened labor rate. Underestimating labor is a common cause of unprofitable jobs.

How many square feet are in a rectangular lawn that is 45 feet by 60 feet?

• a.270 square feet
• b.2,700 square feet✓
• c.1,050 square feet
• d.105 square feet

Area of a rectangle is length times width, so 45 times 60 equals 2,700 square feet. This area figure is then used to calculate seed, sod, fertilizer, or irrigation coverage. Getting the area right is the foundation of most landscape takeoffs.

A fertilizer is applied at 4 pounds per 1,000 square feet. How much is needed for 5,000 square feet?

• a.2 pounds
• b.4 pounds
• c.20 pounds✓
• d.40 pounds

Divide the total area by 1,000 to get 5 units, then multiply by the 4-pound rate to get 20 pounds. Application rates per 1,000 square feet are standard in turf care. Measuring area accurately prevents over-application and fertilizer burn.

Before starting many hardscape or grading projects, a contractor typically must obtain what from the local jurisdiction?

• a.A seed certificate
• b.A fertilizer license only
• c.A paint color approval
• d.The required building or grading permit✓

Grading, retaining walls over a set height, and other hardscape work usually require a permit and inspections from the local building or public works department. Permit review checks drainage, setbacks, and structural safety. Skipping required permits can lead to fines and forced removal.

A sod order covers 2,700 square feet. Sod is sold in pieces covering 10 square feet each. Roughly how many pieces are needed, ignoring waste?

• a.270 pieces✓
• b.2,700 pieces
• c.135 pieces
• d.27 pieces

Divide the total area by the coverage per piece: 2,700 divided by 10 equals 270 pieces. Installers usually add about 5 percent extra for cuts and irregular edges. Ordering by coverage prevents running short mid-installation.

On a landscape plan, a legend or symbol schedule is used to do what?

• a.It shows the property tax value
• b.It provides the full soil test results
• c.It lists the owner's phone number
• d.It identifies each symbol and plant✓

The legend, sometimes called a plant schedule or symbol key, explains what each graphic symbol and abbreviation on the plan means, including plant species, quantities, and sizes. Reading it correctly is essential to an accurate takeoff and installation. It ties the drawing to real materials.

A contractor marks up material and labor to cover office costs, insurance, and profit. This markup is commonly called what?

• a.A material discount
• b.Sales tax
• c.A permit fee
• d.Overhead and profit✓

Overhead and profit is the markup added on top of direct job costs to cover indirect business expenses like office, insurance, and vehicles, plus the profit the company earns. Without adequate overhead and profit, a business cannot sustain itself. It is a standard part of professional estimating.

Before any excavation or trenching in California, the law requires a contractor to do what?

• a.Only notify the adjacent property owners
• b.Wait 30 days before starting work
• c.Dig a test hole first without notice
• d.Contact DigAlert (811) to mark utilities✓

California Government Code section 4216 requires excavators to contact the regional one-call center, DigAlert (811), at least two working days before digging so utility owners can mark their buried lines. This prevents striking gas, electric, and other utilities. Failing to call can cause deadly accidents and legal liability.Gov Code §4216 (DigAlert)

Under Cal/OSHA, a trench generally must be protected by sloping, shoring, or shielding once it reaches what depth?

• a.5 feet, or less where a hazard exists✓
• b.20 feet or deeper in any soil type
• c.50 feet or deeper in any soil type
• d.2 inches or deeper in any loose backfill

Cal/OSHA requires cave-in protection such as sloping, benching, shoring, or a trench box for excavations 5 feet deep or greater, and even shallower trenches if a competent person identifies a hazard. Unprotected trenches can collapse and bury workers in seconds. A competent person must inspect trenches daily.Cal/OSHA Title 8

California's Heat Illness Prevention standard requires employers to provide which of the following to outdoor workers?

• a.Ice cream breaks during the shift
• b.Only drinking water on very hot days
• c.Nothing at all until a worker actually faints
• d.Shade, drinking water, rest breaks, training✓

Cal/OSHA's Heat Illness Prevention standard requires access to shade, plenty of cool drinking water, cool-down rest breaks, acclimatization, and training on recognizing heat illness. High-heat procedures kick in at certain temperatures. Landscapers work outdoors and are a key covered group.Cal/OSHA Title 8

When operating a walk-behind mower on a slope, the recommended practice is to do what?

• a.Mow only when the grass is wet
• b.Mow across the slope, side to side✓
• c.Mow straight up and down the slope
• d.Remove all guards before mowing

With a walk-behind mower you mow across the face of a slope so the machine cannot roll back over you and you keep better footing. The opposite applies to riding mowers, which are safer going up and down. Never remove safety guards, and keep hands and feet away from the deck.

In California, a person who applies restricted-use pesticides for hire generally must hold what?

• a.A county-issued food handler card
• b.No license or certificate of any kind
• c.A Qualified Applicator License (QAL/QAC)✓
• d.Only a valid California driver's license

California requires applicators of pesticides for hire to be properly licensed or certified, such as holding a Qualified Applicator License (QAL) or Qualified Applicator Certificate (QAC) depending on the work. These credentials show the person is trained in safe, legal pesticide use. Landscapers applying pesticides commercially must comply.

A Safety Data Sheet (SDS) for a landscape chemical provides what information?

• a.The pipe size to use for the supply line
• b.The plant's watering schedule
• c.Hazards, PPE, first aid, and storage✓
• d.The retail price of the product

A Safety Data Sheet lists a chemical's hazards, required personal protective equipment, first aid measures, safe handling and storage, and spill response. Employers must keep SDSs accessible to workers under the hazard communication standard. Workers should review the SDS before using any chemical.

When operating a gas-powered chipper/shredder, which practice is safest?

• a.Feed material with bare hands past the intake
• b.Reach into the feed chute while it runs
• c.Wear loose clothing and no eye protection
• d.Wear eye and hearing protection, hands clear✓

Chippers demand snug clothing, eye and hearing protection, and keeping hands well back from the feed opening, using a push stick or the branch itself to feed material. Never reach into the chute while the machine runs, as the feed mechanism can pull in a hand or arm instantly. Always shut down and lock out before clearing a jam.

When using a chainsaw or working near it, which PPE combination is appropriate?

• a.Only sandals and sunglasses on hot days
• b.Chaps, eye and hearing protection, gloves✓
• c.No protection is needed for short cuts
• d.A single glove and shorts in warm weather

Proper chainsaw PPE includes cut-resistant chaps, eye and hearing protection, sturdy gloves, and a hard hat when limbs could fall. This gear protects against kickback, flying debris, noise, and falling branches. Skipping PPE, even for short cuts, causes serious injuries.

Before servicing or clearing a jam in powered landscape equipment, the safest first step is what?

• a.Have a coworker hold the blade steady first
• b.Simply tilt the machine on its side
• c.Increase the throttle to clear it
• d.Shut off the engine and disconnect the plug✓

Powered equipment must be shut off and its energy source isolated, such as disconnecting the spark plug wire or applying lockout/tagout, before anyone clears a jam or services it. This prevents accidental startup that could amputate fingers or hands. It is a fundamental rule for mowers, trimmers, and chippers.

A contractor with employees in California generally must have which of the following?

• a.A written Injury and Illness Prevention Program✓
• b.A single first aid bandage kept in the work truck
• c.Nothing in writing is required at all
• d.Only a business card for the crew lead

Cal/OSHA requires nearly every California employer to establish and maintain a written Injury and Illness Prevention Program (IIPP) that identifies hazards and sets procedures to correct them. It must include training, inspections, and a way for employees to report hazards. It is a foundational Cal/OSHA safety requirement.Cal/OSHA Title 8

When mixing and applying pesticides, the label directions are legally significant because what?

• a.They can be ignored by licensed applicators
• b.They apply only to homeowners
• c.They are only suggestions
• d.The label is the law and must be followed exactly✓

Under pesticide regulations, the product label is a legal document, and using a pesticide in a manner inconsistent with its labeling is a violation. The label specifies rates, sites, PPE, and restrictions that must be followed exactly. This protects applicators, the public, and the environment.

Early signs of heat exhaustion in a worker include which of the following?

• a.Improved strength and steady energy
• b.Heavy sweating, weakness, dizziness, nausea✓
• c.Dry, comfortable skin and clear thinking
• d.No symptoms at all until collapse

Heat exhaustion commonly shows as heavy sweating, weakness, dizziness, nausea, and headache, and it can progress to life-threatening heat stroke if ignored. Affected workers should move to shade, cool down, and drink water. Recognizing these signs early is part of required heat illness training.

When lifting heavy bags of soil or stone, the correct technique is to do what?

• a.Bend the knees and keep the back straight✓
• b.Hold the load out away from the body
• c.Bend at the waist and twist to lift
• d.Lift with straight legs and rounded back

Safe lifting keeps the back straight, bends the knees, and uses the leg muscles to raise the load held close to the body, avoiding twisting. This reduces strain on the lower back, a leading source of landscaping injuries. Heavy or awkward loads should be split or team-lifted.

When working near overhead power lines with tall equipment or ladders, workers must do what?

• a.Keep clearance and treat lines as live✓
• b.Lean the ladder against the power line
• c.Ignore the lines if they look old and worn
• d.Touch the line briefly to test it

All overhead lines should be treated as energized, and workers must keep required minimum clearances with ladders, poles, and equipment such as loaders and tree-trimming gear. Contact or arcing can be fatal. When work must occur close to lines, the utility should be contacted to de-energize or cover them.

Pesticide containers, after being emptied, should be handled how?

• a.Left open in the yard for later reuse
• b.Triple-rinsed and disposed of by label✓
• c.Buried anywhere on the job site after use
• d.Reused to carry drinking water for crews

Empty pesticide containers should be triple-rinsed, with rinse water added to the spray tank, then disposed of per the label and local regulations. They must never be reused for food, water, or other purposes. Proper disposal prevents contamination and accidental poisoning.

A 'competent person' on a trenching job is someone who can do what?

• a.Sell the customer additional trench work
• b.Only operate the excavator safely
• c.Sign the contract for the job
• d.Spot hazards and correct them promptly✓

Cal/OSHA defines a competent person as one capable of identifying existing and predictable hazards and who is authorized to take prompt corrective measures to eliminate them. On trenching jobs this person inspects the excavation, soil, and protective systems daily. Their authority to stop unsafe work is essential.Cal/OSHA Title 8

When operating a trencher, the operator should do what to stay safe?

• a.Keep bystanders clear and watch for utilities✓
• b.Dig first, then call DigAlert afterward
• c.Wear loose jewelry and listen to headphones
• d.Let bystanders stand next to the digging chain

Trencher safety means keeping bystanders back, working only after utilities are located and marked, and keeping hands, feet, and clothing away from the moving digging chain. Loose items can be caught by the chain. Utility location must happen before, not after, digging.

When climbing to prune a tree, a professional arborist relies mainly on what for fall protection?

• a.No protection when pruning low limbs
• b.Holding branches with one hand only
• c.A rope, saddle, and secure tie-in point✓
• d.Standing on the top rung of a stepladder

Professional tree climbers use a rope-and-saddle climbing system tied into a sound anchor point to protect against falls while working aloft. Standing on the top of a ladder or relying on hand grip is unsafe. Proper tie-in and inspected gear are essential for tree work.

Appropriate PPE for a worker applying a liquid herbicide typically includes which of the following?

• a.Chemical-resistant gloves and eye protection✓
• b.Only sunglasses and a light cotton shirt
• c.No gloves, so you can feel the sprayer
• d.Shorts and open sandals in warm weather only

Applying liquid pesticides calls for chemical-resistant gloves, eye protection, long sleeves and pants, closed shoes, and whatever additional protection the label requires, which can include a respirator. The label specifies the minimum PPE for that product. Skin and eye contact with concentrates can cause serious harm.

Backing up a truck and trailer or operating equipment in a crew area is made safer by which practice?

• a.A trained spotter and a working backup alarm✓
• b.Turning off all the mirrors first
• c.Letting anyone stand behind the vehicle
• d.Backing quickly with no one watching

A trained spotter, functioning backup alarm, and careful blind-spot checks greatly reduce the risk of striking a worker or object while backing. Landscape crews often work in tight spaces with equipment moving nearby. Clear communication and awareness prevent serious struck-by incidents.

A C-27 is designing an irrigation system that will inject liquid fertilizer into the mainline downstream of the potable point of connection. Which backflow assembly does that cross-connection call for?

• a.An atmospheric vacuum breaker on each control valve
• b.A pressure vacuum breaker set above the highest head
• c.A double check valve assembly at the point of connection
• d.A reduced pressure principle assembly at the connection✓

Injecting fertilizer makes the system a high-hazard (health hazard) cross-connection, and only the reduced pressure principle assembly is approved for high hazard under both backpressure and backsiphonage. The double check is rated for non-health hazards only. The pressure vacuum breaker and the atmospheric vacuum breaker both stop backsiphonage alone and neither is approved where chemicals are injected under pressure.

An atmospheric vacuum breaker is being considered for a small residential zone. Which installation condition rules it out on that zone?

• a.The zone runs for 45 minutes at a time
• b.The device would sit 14 inches above the highest head
• c.The zone uses spray heads rather than drip tubing
• d.A control valve is located downstream of the device✓

An atmospheric vacuum breaker has a float that must be able to open to atmosphere, so no valve may be placed downstream of it; a downstream valve holds the device under pressure and defeats it. A 45-minute run is well inside the 12-hour continuous pressure limit. Spray heads are a normal downstream use. Fourteen inches of elevation exceeds the six-inch minimum, so that placement is acceptable.

A pressure vacuum breaker is installed on a hillside system where a downstream booster pump was later added. Why is that combination a problem?

• a.The device requires a larger relief port for pump service
• b.The device must be relocated below the pump inlet
• c.The device cannot pass the flow a booster pump produces
• d.The device does not protect against backpressure✓

A pressure vacuum breaker guards only against backsiphonage. A downstream pump can push water back toward the supply as backpressure, which the device is not built to stop, so a reduced pressure principle assembly is needed instead. Flow capacity is a sizing matter, not the hazard. Placing the device below the pump would only make it worse. A pressure vacuum breaker has no relief port to enlarge.

On which irrigation system is a double check valve assembly an acceptable choice for backflow protection?

• a.A system fed in part from an on-site reclaimed water line
• b.A conventional turf system fed only from the potable main✓
• c.A system whose mainline passes through a sewage lift station vault
• d.A system with a chemical injection port on the mainline

The double check valve assembly is approved for continuous pressure but only where the hazard is non-health, which describes a plain turf system on potable water. Reclaimed water, chemical injection, and a mainline exposed inside a sewage vault are all health hazards, and each of those requires the reduced pressure principle assembly that vents to atmosphere when either check fouls.

An inspector rejects a reduced pressure principle assembly that was installed inside a below-grade valve box. What is the basis for the rejection?

• a.The assembly must be installed with the flow arrow pointing down
• b.The assembly must be within five feet of the water meter
• c.The relief port must discharge freely to atmosphere above grade✓
• d.The assembly must be protected from sunlight at all times

A reduced pressure assembly dumps water out of a relief port whenever the checks foul, so it has to sit above grade where that discharge is visible and cannot be submerged; a flooded box would let contaminated water enter through the port. There is no five-foot rule tying it to the meter. These assemblies are installed horizontally in the direction of the flow arrow, and sunlight is not the governing concern.

After a backflow assembly is installed on a new commercial landscape, what does the water purveyor normally require next?

• a.A dye test of the downstream laterals for cross-connections
• b.A pressure test of the mainline witnessed by the local building inspector
• c.A field test by a certified backflow tester before the system is used✓
• d.A letter from the designer stating the hazard level of the site

Backflow assemblies are mechanical devices that can pass a visual check and still leak, so purveyors require a field test by a certified tester at installation and on a recurring schedule after that. A mainline pressure test proves the pipe, not the assembly. A designer letter is not a substitute for a physical test. Dye testing laterals is not part of the acceptance of the assembly.

An anti-siphon control valve is being set on a bed that steps uphill from the valve manifold. Where must the valve be placed?

• a.At the lowest head in the zone so that the lateral is able to drain
• b.Above the highest head the valve serves, by the required clearance✓
• c.Level with the average elevation of the heads in the zone
• d.Inside a valve box with the bonnet at finish grade

An anti-siphon valve carries an atmospheric vacuum breaker in its bonnet, and that breaker only works when it sits above every outlet it protects, so the valve must be higher than the highest head in the zone. Setting it at the low point or at an average elevation leaves heads above the breaker. Burying it in a box defeats the device entirely, since the bonnet must be open to air.

A fire hydrant is flowed on the street and the irrigation system briefly draws water backward toward the main. What is this event called?

• a.Backpressure from the downstream zone
• b.Thermal expansion in the service line
• c.Backsiphonage caused by negative supply pressure✓
• d.Water hammer traveling back through the supply main

Heavy draw on the main drops supply pressure below the pressure in the irrigation piping, and the resulting vacuum pulls water backward, which is backsiphonage. Backpressure is the opposite case, where downstream pressure rises above the supply. Water hammer is a surge from a valve closing quickly. Thermal expansion raises pressure in a closed system and does not reverse flow direction.

A landscape sits 60 feet uphill of the water meter and the system feeds a booster pump at the bottom of the hill. Which backflow condition is created?

• a.Backsiphonage, because elevation lowers the available supply pressure
• b.Neither, because elevation gain cancels the pump pressure
• c.Neither, because the pump discharges away from the meter
• d.Backpressure, because the pump can exceed the supply pressure✓

A pump raises pressure on the downstream side, and any time downstream pressure can exceed supply pressure the system can push water back toward the main, which is backpressure. Backsiphonage requires a vacuum in the supply, which a pump does not create. A pump does not prevent reverse flow when it is off, and elevation gain does not cancel the pressure the pump can develop.

A homeowner asks a C-27 licensee to replace the corroded potable water service line from the city meter to the house while the crew is on site trenching for irrigation. How should the licensee respond?

• a.Decline or subcontract it, since a water service is plumbing work✓
• b.Perform the work, since the trench for it is already open
• c.Perform the work if the homeowner pulls the permit personally
• d.Perform the work if the pipe size matches the irrigation mainline

The C-27 classification covers landscape systems including irrigation and drainage, but the potable service supplying the building is plumbing and belongs to a plumbing classification, so it must be declined or subcontracted to a properly licensed contractor. An open trench, a matching pipe size, and who pulls the permit change nothing about which classification is authorized to do the work.16 CCR §832.27

A designer sizes a PVC mainline so that velocity stays at or below about five feet per second. What is the main reason for that limit?

• a.To hold friction loss under one psi per hundred feet
• b.To keep the pipe from collapsing when the system drains
• c.To keep the water temperature stable in the mainline
• d.To limit surge pressure when a valve closes quickly✓

Surge pressure from a closing valve rises with the velocity of the moving column, so capping velocity near five feet per second is how designers keep water hammer from splitting fittings. Pipe collapse on draining is not a pressurized-line concern. Friction loss is a separate calculation with no such fixed target. Water temperature in a buried line is not affected by design velocity.

A zone sits 30 feet higher than the point of connection. Roughly how much pressure is lost to elevation alone?

• a.About 10 psi
• b.About 13 psi✓
• c.About 3 psi
• d.About 7 psi

Every foot of elevation gain costs about 0.433 psi, so 30 feet costs roughly 13 psi, which must be subtracted before friction losses are even considered. The 3 psi figure would apply to about seven feet of rise, 7 psi to about sixteen feet, and 10 psi to about twenty-three feet. Underestimating this loss is the usual reason uphill zones run at poor pressure.

A drip zone is located 45 feet downhill from the valve. What does that elevation change do to pressure at the emitters?

• a.Has no effect, because drip emitters are self-adjusting
• b.Adds roughly 19 psi, which may require pressure regulation✓
• c.Has no effect, because the valve sets downstream pressure
• d.Removes roughly 19 psi, which may require a larger lateral

Falling elevation adds about 0.433 psi per foot, so 45 feet of drop adds roughly 19 psi, easily enough to blow emitters off tubing without a regulator. It is a gain, not a loss, so a larger lateral is not the fix. Only pressure-compensating emitters self-adjust, and only within a range. A control valve does not hold a fixed downstream pressure.

A gauge on a hose bibb reads 78 psi with nothing running and 52 psi while a rotor zone operates. What do these two readings represent?

• a.Design pressure and residual pressure at the head
• b.Service pressure and regulated pressure
• c.Static pressure and dynamic working pressure✓
• d.Surge pressure and operating pressure

Pressure with no flow is static pressure and pressure measured while water moves is dynamic or working pressure, and the difference is what friction and demand consume. Design pressure is a target the designer selects, not a gauge reading. Surge pressure is the spike from a closing valve. Regulated pressure is whatever a regulator is set to deliver.

A lateral carrying 15 GPM in one-inch pipe is losing too much pressure over a 300-foot run. Which change reduces friction loss the most?

• a.Increasing the lateral to the next larger pipe size✓
• b.Adding a second control valve on the same lateral
• c.Switching from solvent weld to gasketed fittings throughout
• d.Raising the controller run time for that station

Friction loss falls sharply as the inside diameter grows, so stepping up one pipe size is the direct fix for a long lateral. Fitting style changes losses only marginally. A second valve on the same lateral does not change the flow the pipe must carry. Run time affects how long water is applied and has no effect at all on pressure loss along the pipe.

Comparing Class 200 and Schedule 40 PVC of the same nominal size, which statement is accurate?

• a.Class 200 is rated for higher continuous pressure
• b.Schedule 40 has a larger bore and a lower pressure rating
• c.Class 200 has a thicker wall and a smaller bore
• d.Schedule 40 has a thicker wall and a smaller bore✓

Both share the same outside diameter, and Schedule 40 achieves its higher rating with a thicker wall, which leaves a smaller inside bore and slightly more friction loss. Class 200 is the thinner-walled, lower-rated pipe with the larger bore, so the first two statements reverse the relationship and the third assigns Class 200 traits to Schedule 40.

A crew is solvent-welding a PVC mainline joint on a warm day. Which step is required for a sound joint?

• a.Sand the spigot end smooth so the cement spreads evenly
• b.Chill the pipe end so the cement sets more slowly
• c.Wipe the socket with solvent thinner and let it dry fully
• d.Apply primer to soften both surfaces before the cement✓

Primer softens the PVC on both the pipe and the fitting so the cement can fuse them, and skipping it is the common cause of joints that weep under pressure. Thinner cleans but does not soften the surface. Chilling the pipe slows the chemical reaction rather than helping it. Sanding the spigot smooth removes material and can leave the joint loose.

Rotor heads on a turf zone keep snapping off at the riser when they are struck by mowers. Which detail should have been installed?

• a.A swing joint between the lateral and the head✓
• b.A brass nipple between the lateral and the head
• c.A cutoff riser set two inches below finish grade
• d.A check valve in the body of each rotor head

A swing joint lets the head move under impact and be reset to grade without breaking the lateral, which is why it is standard under rotors in turf. A brass nipple is rigid and transfers the impact straight into the fitting. A check valve stops low-head drainage but does nothing for impact. Setting a head below grade blocks the spray pattern.

Emitters on a new drip zone plug within the first season on a system fed from a well. What was most likely omitted at the head of the zone?

• a.An air and vacuum relief valve at the high point
• b.A pressure-compensating manifold on each run
• c.A flush cap at the end of each lateral
• d.A filter of roughly 150 to 200 mesh✓

Drip emitters have very small passages, so a fine filter in the 150 to 200 mesh range at the head of the zone is what keeps well sediment out of them. A compensating manifold addresses pressure, not particles. Air relief protects against soil being drawn in when the line drains. Flush caps help clear settled debris but do not stop it from arriving.

A drip zone is teed off a mainline that runs at 70 psi. What must be added for the emitters to operate correctly?

• a.A pressure regulator sized to the zone flow✓
• b.A larger valve to slow the entering velocity
• c.A second filter downstream of the emitters
• d.A booster pump sized to the emitter count

Most drip emitters are built for roughly 20 to 30 psi, so a regulator matched to the zone flow is what brings 70 psi down to the operating range and keeps fittings from blowing apart. A booster pump raises pressure that is already too high. A larger valve does not reduce downstream pressure. A filter placed after the emitters cannot protect them.

A single drip lateral runs from the bottom of a slope to the top of a 20-foot rise. Which emitter type keeps output even along that run?

• a.Pressure-compensating emitters rated over a pressure range✓
• b.Turbulent-flow emitters spaced at wider intervals up the run
• c.Vortex emitters installed only on the upper half
• d.Diaphragm emitters fed from a larger lateral

Pressure-compensating emitters hold a nearly constant discharge across a stated pressure band, which is exactly what a run that climbs 20 feet needs. Turbulent-flow emitters still put out more where pressure is higher regardless of spacing. Mixing emitter types on one lateral produces uneven output. A larger lateral reduces friction but does nothing about the elevation difference.

Inline drip tubing is being laid in a sandy bed and in a clay bed on the same property. How should emitter spacing differ?

• a.Identical, because emitter flow rate governs the wetted width
• b.Closer in the clay, because clay absorbs water more quickly
• c.Closer in the sand, because water moves down more than out✓
• d.Wider in the sand, because water travels farther laterally

Sand has large pores, so water drops nearly straight down and the wetted bulb is narrow, which calls for closer emitter spacing to join the bulbs. Clay spreads water laterally and tolerates wider spacing. Flow rate affects bulb size but does not remove the soil texture difference, and clay absorbs water more slowly rather than more quickly.

A subsurface drip zone under turf is drawing soil into the tubing each time the valve closes. Which component prevents this?

• a.A finer filter at the head of the zone
• b.An air and vacuum relief valve at the zone high point✓
• c.A pressure regulator set ten psi lower
• d.A flow sensor wired to the controller for that zone only

When the valve shuts, the draining lateral pulls a vacuum and sucks soil back through the emitters, and an air and vacuum relief valve at the high point breaks that vacuum by letting air in. A flow sensor only reports flow. Filtration protects against particles entering from the supply, not from the soil side. Lowering regulated pressure does not stop the drain-down vacuum.

After a zone shuts off, water keeps running out of the two lowest spray heads on a sloped lawn. What corrects this?

• a.Installing a master valve at the point of connection
• b.Raising the controller run time for that station
• c.Installing check valves in the low heads of the zone✓
• d.Adding a pressure regulator ahead of the zone valve

Water remaining in the lateral drains through whichever heads sit lowest, and check valves in those heads hold it back. Longer run times worsen the puddle. A master valve controls the mainline and has no effect on a lateral that is already full. Pressure regulation controls operating pressure and does not stop gravity drainage after shutoff.

Spray heads with a 15-foot radius are being laid out on a rectangular lawn. What spacing does head-to-head coverage call for?

• a.About 30 feet apart, at the full diameter of throw
• b.About 8 feet apart, at half the radius of throw
• c.About 15 feet apart, so each head throws to the next✓
• d.About 22 feet apart, at one and a half times the radius

Head-to-head layout means the stream from one head reaches the adjacent head, so spacing equals the radius, here about 15 feet. Spacing at 22 or 30 feet leaves the weak outer edge of each pattern unsupported and produces dry rings. Spacing at 8 feet doubles the water applied and wastes both heads and pressure.

A site is exposed to steady afternoon wind. How should the designer adjust spray head spacing?

• a.Reduce spacing below the normal head-to-head distance✓
• b.Increase spacing and raise operating pressure to push through the wind
• c.Increase spacing and change to a finer nozzle pattern
• d.Keep spacing the same and add a second controller program

Wind shortens and distorts the pattern, so tightening spacing below the usual head-to-head distance is how the design keeps coverage uniform. Raising pressure produces finer droplets that blow away more readily. A second program changes timing, not coverage. Finer nozzles at wider spacing make drift worse rather than better.

A zone contains quarter-circle, half-circle, and full-circle spray heads on the same laterals. What must be true of the nozzles for the zone to water evenly?

• a.Every head must carry a nozzle of the same flow rate
• b.Quarter-circle heads must be placed on their own lateral
• c.Full-circle heads must run at a higher operating pressure
• d.Nozzle flow must scale with arc to match precipitation✓

A full circle covers four times the area of a quarter, so its nozzle must pass roughly four times the flow for the two to apply water at the same depth per hour, which is what matched precipitation rate nozzle sets provide. Equal flow at unequal arcs floods the quarters. Changing pressure by head is not practical. Splitting arcs onto separate laterals does not fix the nozzle mismatch.

A remodel connects several spray heads and two rotors to the same control valve. What is the consequence?

• a.The spray heads will mist because the rotors restrict flow
• b.One group is overwatered while the other stays dry✓
• c.The valve will fail to open because of mixed flow demand
• d.The rotors will lose pressure and stop rotating entirely

Rotors apply water far more slowly than sprays, so a run time that satisfies the rotors drowns the spray area and a run time that suits the sprays leaves the rotor area dry. The valve opens normally on mixed flow. Rotors may still turn, and the misting seen at spray heads comes from excess pressure rather than from sharing a valve.

A plan groups plants onto valves by water need, sun exposure, and root depth. What is this design practice called?

• a.Hydrozoning the landscape✓
• b.Establishing the irrigation audit baseline
• c.Calculating the landscape coefficient
• d.Setting the distribution uniformity target

Grouping plants with similar water demand and exposure onto a common valve is hydrozoning, and it is the core requirement that lets a schedule serve every plant on a station. An audit baseline is a measurement of an installed system. Distribution uniformity describes how evenly a zone applies water. The landscape coefficient is a number used in a water budget calculation.CA MWELO (Title 23)

Water begins running off a clay slope about eight minutes into a 20-minute rotor cycle. What is the correct schedule change?

• a.Keep the 20 minutes and add a wetting agent to the soil
• b.Cut the cycle to eight minutes and water every other day
• c.Water for 40 minutes once a week to drive moisture deeper
• d.Run three cycles of about seven minutes with soak between✓

Runoff starts when the application rate passes the soil intake rate, so splitting the total into short cycles separated by soak periods lets the same depth of water enter without leaving the slope. Simply shortening the cycle underwaters the root zone. A wetting agent does not raise clay intake enough to matter. Doubling the run time multiplies the runoff.

Four soils are being compared for irrigation scheduling. Which has the lowest infiltration rate and therefore the highest runoff risk?

• a.A gravelly loam over decomposed granite
• b.A coarse sand with little organic matter
• c.A compacted silty clay on a graded pad✓
• d.A sandy loam amended with compost

Fine particles and compaction together produce the smallest pore spaces, so a compacted silty clay takes water in most slowly and sheds the rest. Coarse sand accepts water fastest. An amended sandy loam has good structure and intake. A gravelly loam over decomposed granite drains readily and rarely generates runoff.

A California schedule is built around a reference evapotranspiration value pulled from a CIMIS station. What does that value describe?

• a.The depth of water a drip zone applied per hour
• b.The depth of water a specific landscape lost last week
• c.The water use of a standard reference crop under the local weather✓
• d.The share of applied water that reached the root zone

Reference evapotranspiration is the water use of a standardized, well-watered reference surface under measured local weather, and it becomes site specific only after a plant factor is applied. It is not a measurement of one landscape, not an application rate, and not a measure of how efficiently water reaches roots, which is what distribution uniformity and efficiency describe.

On a MWELO project, what is the relationship the designer must demonstrate between estimated total water use and maximum applied water allowance?

• a.The two are calculated for separate hydrozones and not compared
• b.Estimated use must not exceed the allowance✓
• c.Estimated use must equal the allowance exactly
• d.The allowance must not exceed estimated use

The allowance is a ceiling set from local reference evapotranspiration and landscape area, and the design passes when estimated total water use lands at or below it. Requiring an exact match would make almost every efficient design fail. Reversing the inequality would force overdesign. The two figures are calculated for the whole landscape precisely so they can be compared.CA MWELO (Title 23)

Under MWELO, a landscape water budget is smaller on a site with which characteristic?

• a.A larger area of special landscape area such as a play field
• b.A drip system rather than an overhead spray system
• c.A lower local reference evapotranspiration value✓
• d.A higher proportion of trees to shrubs in the plan

The allowance is driven by local reference evapotranspiration and landscape area, so a cooler, lower-demand climate zone yields a smaller budget. Special landscape areas are given a higher allowance and raise the budget. The mix of trees and shrubs and the choice of irrigation method affect estimated use and efficiency but are not what sets the allowance itself.CA MWELO (Title 23)

A MWELO project includes a three-foot-wide planter strip between a sidewalk and a curb. What does the ordinance say about irrigating it?

• a.Overhead spray is prohibited and subsurface or drip should be used✓
• b.It may use spray heads if they are pressure regulated
• c.Overhead spray is allowed because the strip is under 500 square feet
• d.It may use spray heads if run only between 8 pm and 10 am

Section 493.2.2(d)(6) requires that areas less than 10 feet in width in any direction be irrigated with subsurface irrigation or other means producing no water waste, runoff, or overspray, so a three-foot strip must use drip or subsurface. Section 493.2.2(d)(10) independently bars overhead irrigation within 24 inches of any non-permeable surface, and a 36-inch strip bounded by sidewalk and curb leaves no compliant location for a spray head. Pressure regulation and night watering reduce waste but do not lift either restriction, and square footage is not the test.23 CCR §493.2.2(d)(6)

Which controller feature does MWELO require on a new automatic irrigation system?

• a.A separate transformer for each group of six stations
• b.Weather-based or soil moisture control with a rain shutoff✓
• c.A mechanical timer with at least four independent programs
• d.A remote shutoff accessible from the public right of way

MWELO requires controllers that adjust to actual conditions, meaning weather-based or soil moisture-based control together with a sensor that suspends watering during rain. Program count on a mechanical timer is not the requirement. A public remote shutoff is not called for. Transformer arrangement is an electrical detail with no bearing on the ordinance.CA MWELO (Title 23)

A master valve and a flow sensor are wired to a smart controller on a large commercial landscape. What is the main benefit of the pair?

• a.Each station can be assigned a separate precipitation rate value
• b.Pressure at the far end of the mainline is held constant
• c.A broken mainline can be detected and shut down automatically✓
• d.Backflow protection is provided without a separate assembly

The sensor watches flow while the master valve can close the mainline, so unexpected flow such as a broken pipe triggers an automatic shutdown instead of a week of running water. Precipitation rates come from nozzles and spacing. Neither device regulates pressure. Neither is an approved backflow assembly, so a separate assembly is still required.

A technician measures 3 ohms across a solenoid on a station that blows the controller fuse. What does that reading indicate?

• a.A weak transformer on the controller side
• b.An open circuit in the field wiring
• c.A shorted solenoid that must be replaced✓
• d.Normal resistance for a 24-volt solenoid

Irrigation solenoids normally read roughly 20 to 60 ohms, so a reading of 3 ohms means the coil has shorted and is drawing enough current to blow the fuse. An open circuit reads as infinite resistance, not near zero. The reading is far below the normal band. A weak transformer lowers voltage but does not change coil resistance.

One station on a 12-station controller will not energize, while every other station runs. Where should troubleshooting begin?

• a.At that station wire and its solenoid, which serve only that zone✓
• b.At the controller transformer, which feeds every station on the unit
• c.At the common wire, which is shared by every station
• d.At the master valve, which opens for every station

A fault that affects one station and no other has to lie in the parts unique to that station, namely its field wire, its splice, and its solenoid. The transformer, the common wire, and the master valve are all shared, so a failure in any of them would take down every station rather than one.

A control valve keeps running after the controller shuts the station off. What is the most likely cause?

• a.Grit lodged under the diaphragm holding the valve open✓
• b.An undersized lateral downstream of the valve
• c.A failed rain sensor holding the station open
• d.A reversed common wire at the controller terminal

A diaphragm valve closes when pressure rebuilds above the diaphragm, and grit that blocks the seat or the port keeps it from seating, so the zone keeps flowing. A rain sensor interrupts the circuit and stops watering rather than continuing it. Common wires are not polarity sensitive on a 24-volt circuit. Lateral size affects pressure, not valve closure.

A C-27 needs 120-volt power at a new controller location on the side of a house. What is the correct approach?

• a.Run the branch circuit in conduit and have it inspected later
• b.Have a licensed electrical contractor install the branch circuit✓
• c.Splice into the nearest exterior light circuit inside a valve box
• d.Install the circuit because the controller is landscape equipment

Low-voltage valve wiring is part of the irrigation system, but installing a new 120-volt branch circuit is electrical work that belongs to an electrical classification, so it must go to a licensed electrical contractor. Adding conduit or an after-the-fact inspection does not change who may perform it. Splicing line voltage in a valve box is both unlicensed work and a serious hazard.

Field splices on 24-volt valve wire are being made at a remote valve manifold. What is required for a durable installation?

• a.Crimped butt connectors sleeved in irrigation tubing
• b.Soldered joints wrapped in electrical tape below the mainline
• c.Waterproof splice connectors made up inside a valve box✓
• d.Twisted wire nuts taped over and buried in the trench

Direct burial wire splices corrode unless they are sealed, so waterproof connectors placed in an accessible valve box are the standard. Taped wire nuts buried in soil fail within a few seasons. Tape over solder is not waterproof and burying the splice under the mainline makes it unreachable. Crimps in tubing are not sealed against moisture.

What is the purpose of the isolation ball valve installed just upstream of a valve manifold?

• a.To regulate downstream pressure on the zones it feeds
• b.To close the manifold for service without draining the main✓
• c.To meter the flow through the manifold for the system flow sensor
• d.To relieve surge pressure when a station closes

An isolation valve lets a technician close off one manifold and repair a control valve while the rest of the mainline stays charged. It is a full-port shutoff, not a regulator, and it does not relieve surge, which is handled by design velocity and slow-closing valves. Metering is a flow sensor function, not a shutoff function.

A quick coupler valve is installed in a large planting bed. What is its normal use?

• a.To break vacuum in a subsurface drip lateral
• b.To provide a temporary hose connection for hand use✓
• c.To drain the mainline for repairs at the low point
• d.To provide a manual override for the nearest station

A quick coupler is opened with a removable key so a hose can be attached wherever hand watering or washdown is needed, then closed and left flush with grade. Draining is done at a drain valve, vacuum relief at an air relief valve, and manual station override at the control valve bleed screw or the controller.

Spray heads on a new zone produce a fine fog rather than droplets. What is the correct correction?

• a.Move to a larger nozzle so more water leaves each head
• b.Reduce the run time so less water is applied per cycle
• c.Add pressure regulation so heads run near rated pressure✓
• d.Add a second valve so fewer heads run at once

Fogging means the heads are operating well above their rated pressure, and pressure regulation at the head or on the zone brings them back into range. Shorter run times leave the same fog and the same drift. A larger nozzle at excessive pressure still atomizes. Fewer heads per valve raises pressure further and makes the problem worse.

A trench crosses a future paver driveway. What should be installed before the paving crew arrives?

• a.A pull box centered under the driveway for wire access
• b.A sleeve about twice the diameter of the carrier pipe✓
• c.A cast iron pipe carrying the mainline under the drive
• d.A concrete thrust block at each side of the driveway

A sleeve about twice the diameter of the carrier pipe lets the mainline and wire be pulled or replaced later without disturbing pavement, which is why sleeving is scheduled before paving. Cast iron is not used for irrigation laterals. Thrust blocks belong at direction changes on large pressure mains. A pull box under a driveway cannot be reached.

Why is an irrigation mainline normally buried deeper than the laterals it feeds?

• a.It carries a larger volume and needs more soil for support
• b.It must be below the frost line in every California climate zone
• c.It stays under constant pressure and is more exposed to damage✓
• d.It must clear the drain lines that cross the same trench

A mainline holds pressure at all times, so a shovel or aerator strike causes an immediate and continuous leak, and extra cover is cheap protection. Volume does not dictate depth. Drain line crossings are handled case by case. Frost depth is not the governing concern across California, where most systems are buried for damage protection rather than freezing.

During a catch-can audit, the driest cups collect about half as much water as the average cup. What does that tell the auditor?

• a.The zone precipitation rate is above the intake rate of the soil profile
• b.The nozzles are operating below their rated pressure
• c.The controller run time is set too short for the zone
• d.Distribution uniformity is poor and dry spots will drive overwatering✓

Wide variation between cups is a distribution uniformity problem, and the usual response in the field is to run the whole zone longer to green up the dry spots, which floods everywhere else. Run time affects total depth but not evenness. Intake rate is measured by watching for runoff. Low pressure is one possible cause but is not what the cup spread by itself demonstrates.

An audit finds mismatched nozzle brands and several worn nozzles on the same turf zone. What is the direct consequence?

• a.A rise in the maximum applied water allowance for the site
• b.A drop in static pressure measured at the point of connection
• c.Increased low-head drainage at the end of each cycle
• d.Uneven precipitation across the zone and reduced uniformity✓

Nozzles from different families throw different patterns and rates, and worn nozzles spray more water at a shorter radius, so the zone applies water unevenly. Static pressure at the meter is unaffected by nozzle wear. The water allowance is a calculated ceiling, not something nozzles change. Low-head drainage depends on head elevation and check valves.

A zone applies water at 1.6 inches per hour and the schedule calls for 0.4 inches. What run time delivers that depth?

• a.10 minutes
• b.40 minutes
• c.24 minutes
• d.15 minutes✓

Dividing the required depth by the precipitation rate gives 0.4 divided by 1.6, or 0.25 hours, which is 15 minutes. Ten minutes applies about 0.27 inches. Twenty-four minutes applies about 0.64 inches. Forty minutes applies more than an inch, which on most soils would run off long before the cycle ended.

A zone of eight heads at 2.5 GPM each covers 1,200 square feet. What is its precipitation rate?

• a.About 0.8 inches per hour
• b.About 1.6 inches per hour✓
• c.About 1.2 inches per hour
• d.About 2.4 inches per hour

Total flow is 20 GPM, and 96.3 times 20 divided by 1,200 gives about 1.6 inches per hour. The 0.8 figure would come from half the flow or twice the area. The 1.2 figure does not follow from either input. The 2.4 figure would require roughly 30 GPM over the same area.

Rotary nozzles are substituted for standard spray nozzles on a sloped turf area. What schedule change follows?

• a.Shorter run times, because rotary nozzles apply water faster
• b.Longer run times, because rotary nozzles apply water more slowly✓
• c.Shorter run times, because the streams resist wind drift
• d.The same run times, because the nozzles thread onto the same bodies

Rotary nozzles put out a much lower precipitation rate than fixed sprays, so the same depth of water takes noticeably longer, which is exactly why they suit slopes and tight soils. They apply water more slowly rather than faster. Their wind resistance is real but does not shorten run time, and sharing a body does not mean sharing an application rate.

Heads along a walkway are throwing water across the concrete during every cycle. What is the first adjustment to make?

• a.Set the arc and radius so spray stops at the turf edge✓
• b.Lower the controller run time on that station by half
• c.Raise the heads on taller risers to clear the walkway
• d.Move the station to an early morning start time

Overspray onto pavement is a coverage problem, so adjusting each head to the correct arc and reducing radius so the pattern ends at the edge fixes the cause. Halving run time leaves the same overspray in every cycle. Taller risers throw water farther onto the walk. An earlier start time hides the waste rather than stopping it.

Why are irrigation cycles commonly scheduled for the hours before sunrise?

• a.Soil intake rate is naturally higher during darkness
• b.Municipal water pressure is lowest and gentler on the pipe
• c.Wind and evaporation losses are lowest at that time✓
• d.Foliage stays wet longer, which reduces plant stress

Early morning brings the calmest air and the lowest evaporative demand, so more of the applied water reaches the root zone. Pressure is typically higher rather than lower at night. Soil intake depends on texture and structure, not on time of day. Extended leaf wetness actually encourages foliar disease and is a reason to avoid evening watering.

A one-inch meter is rated at 50 GPM maximum. What flow should the designer plan the largest zone around?

• a.About 35 to 37 GPM, three quarters of the rating✓
• b.About 25 GPM, exactly half the rating
• c.About 60 GPM, since peak demand is brief
• d.The full 50 GPM, which the meter is rated to pass

Designers hold continuous irrigation demand near three quarters of the meter rating so friction loss through the meter stays reasonable and household demand can occur at the same time. Designing at the full rating leaves nothing for the building. Exceeding the rating is not acceptable at any duration. Half the rating is unnecessarily conservative and drives up zone count.

Where should a pressure gauge be attached to read the static pressure available to a proposed system?

• a.At an outside hose bibb with no water flowing on site✓
• b.At the controller location using a test manifold
• c.At the far end of the existing mainline while a zone runs
• d.At a spray head riser with the zone valve open

Static pressure is measured with no flow anywhere on the service, and an exterior hose bibb near the point of connection gives a clean reading. Reading at an open head or during a running zone gives dynamic pressure instead. A controller is an electrical enclosure with no water connection to test.

A hydraulic worksheet lists losses for the meter, the backflow assembly, the mainline, the valve, and the lateral. Why must the backflow assembly appear on it?

• a.It adds pressure downstream when the checks are clean
• b.It consumes a significant share of available pressure✓
• c.It sets the maximum velocity allowed in the mainline
• d.It reduces the flow the meter is able to deliver

A reduced pressure assembly typically eats about ten to twelve psi and even a double check takes several, so leaving it off the worksheet is a common reason zones run short of pressure. It does not change what the meter can deliver, it never adds pressure, and velocity limits come from pipe sizing rather than from the assembly.

A new commercial landscape exceeds the size threshold at which MWELO calls for a dedicated landscape water meter. What is the purpose of that meter?

• a.To provide a shutoff the fire department can operate in an emergency
• b.To allow the water purveyor to bill landscape water at a lower rate
• c.To keep landscape flow from reducing pressure inside the building
• d.To measure landscape use separately and compare it to the budget✓

Separating landscape flow from building flow is what makes it possible to compare actual use against the calculated water budget and to spot leaks. Rate structures vary by purveyor and are not the ordinance purpose. A meter is not a fire department connection, and metering does not by itself protect building pressure.CA MWELO (Title 23)

A mature oak sits in the middle of a new lawn area. What irrigation approach protects the tree?

• a.Put the tree on its own valve for deep, infrequent watering✓
• b.Include the tree in the turf zone and extend the run time
• c.Place a ring of spray heads at the trunk to soak the root crown
• d.Install a bubbler at the trunk and run it with every turf cycle

Established oaks decline under frequent shallow turf watering, especially near the trunk, so a separate valve allowing infrequent deep irrigation out toward the drip line is the protective choice. Sharing the turf schedule keeps the root crown wet. Heads or bubblers at the trunk concentrate water exactly where crown rot begins.

A bubbler is specified for a newly planted 24-inch box tree. What condition must accompany it?

• a.A check valve so the basin does not drain after shutoff
• b.A finer filter than the rest of the system requires
• c.A watering basin or root ball area that can hold the flow✓
• d.A pressure-compensating emitter installed on the same outlet

Bubblers discharge at a high rate in a small area, so a formed basin or a contained root ball area is required or the water simply runs off. A separate compensating emitter on the same outlet is redundant. A check valve addresses drainage in the lateral, not basin retention. Bubbler orifices are large and need no special filtration.

An older system is being retrofitted from spray heads to inline drip in the shrub beds. Which existing component most often has to be changed at the valve?

• a.The zone needs a larger solenoid to open at lower flow
• b.The zone needs a filter and a pressure regulator added✓
• c.The zone needs its common wire replaced with heavier gauge
• d.The zone needs the control valve relocated above the beds

Drip runs at low pressure and cannot tolerate particles, so a retrofit kit adding filtration and regulation at the valve is the standard change. Solenoids do not vary with flow. Wire gauge is unrelated to converting the piping. Relocating the valve uphill matters only for anti-siphon devices, not for a drip conversion.

How often should the ends of inline drip laterals be flushed on a maintained system?

• a.On a routine schedule, such as each season's start✓
• b.Once at installation, since the lines then stay sealed
• c.Only when emitter output visibly drops off
• d.Only after the filter has been replaced

Fines that pass the filter settle at the far end of every lateral, so routine flushing on a set schedule clears them before they plug emitters. Waiting for visible output loss means damage has already happened. Filter replacement does not remove what is already in the line, and a sealed system still accumulates sediment and biofilm over time.

A crew must locate a buried valve on a system with no as-built drawing. Which method is the appropriate first step?

• a.Energize the station and trace the valve wire with a locator✓
• b.Pressurize the zone and listen for flow at the meter
• c.Excavate along the mainline at ten-foot intervals
• d.Cut the lateral at the nearest head and follow it back

A wire tracer follows the energized valve wire directly to the solenoid, which is the least destructive way to find a buried valve. Random trenching along the mainline damages pipe and landscape. Listening at the meter confirms flow but gives no location. Cutting a lateral creates a repair without narrowing the search.

Which practice makes a valve manifold serviceable years after installation?

• a.Grouping all valves for the site into one continuous trench
• b.Solvent welding the valves directly to the mainline tee
• c.Setting the valve boxes two inches below finish grade
• d.Installing unions or slip fix couplings on each valve outlet✓

A union or repair coupling at each valve lets a technician remove one body without cutting and rebuilding the manifold. Welding valves solidly into the tee forces a cut-out for every repair. Boxes buried below grade cannot be found. Grouping all valves in one trench is a layout choice that does not make individual valves easier to replace.

A soil moisture sensor is added to an existing controller. How does it change operation?

• a.It calculates run times from local reference evapotranspiration data
• b.It adjusts nozzle pressure at each head to match soil conditions
• c.It allows a scheduled cycle only when soil moisture is below a set point✓
• d.It measures flow through the mainline and closes the master valve

A soil moisture sensor reports the condition of the root zone and permits or skips the programmed cycle based on a threshold. Using weather data to compute run times is what a weather-based controller does. Flow measurement and shutdown belong to a flow sensor and master valve. No sensor adjusts pressure at the heads.

An irrigation plan calls for check valves at heads on a slope and pressure regulation at every head. What performance problem do these two details address?

• a.Excess flow demand that exceeds the available meter capacity
• b.Poor uniformity caused by mismatched nozzle arcs
• c.Water waste from low-head drainage and from misting✓
• d.Root intrusion into laterals installed below grade

Check valves stop the lateral from draining out the lowest heads after each cycle, and head pressure regulation stops fogging at high pressure, so together they cut two common sources of waste. Arc mismatch is a nozzle selection issue. Meter capacity is addressed by splitting zones. Root intrusion is a subsurface drip concern handled by treated emitters.

A designer is deciding where to place the point of connection for a new system. Which location is generally preferred?

• a.At the farthest hose bibb so the run to the valves is shortest
• b.Downstream of the building pressure regulator inside the garage
• c.At the water heater cold inlet where a tee already exists
• d.On the service line ahead of the building, downstream of the meter✓

Connecting on the service between the meter and the building keeps irrigation demand from competing with fixtures inside and gives the backflow assembly a clean above-grade location. A connection past the house regulator inherits reduced pressure. A water heater inlet is a fixture supply, not a system connection. A distant hose bibb is undersized for zone flow.

Which statement about installing an irrigation system on a site served by recycled water is accurate?

• a.Recycled and potable lines may share a trench if both are Schedule 40
• b.Recycled water systems are exempt from backflow protection requirements
• c.Recycled water lines are marked with green tape and green valve boxes
• d.Recycled water piping is identified in purple and kept separate from potable✓

Recycled water piping, valve boxes, and identification tape are purple, and the system must be physically separated from potable piping with no cross-connections. Sharing a trench without required separation is not acceptable regardless of pipe class. Green identifies sewer, not recycled water. Recycled water is a health hazard and increases rather than removes backflow requirements.

A newly seeded lawn and an established shrub bed are on the same controller. How should the seeded area be scheduled during establishment?

• a.The same program as the shrubs, with a higher station multiplier
• b.Deep watering twice a week to encourage rooting downward
• c.Brief cycles several times a day to keep the seedbed damp✓
• d.One long cycle each morning to soak the full root zone

Seed germinates in the top fraction of an inch, which dries within hours, so short frequent cycles are correct until the stand fills in. A single long cycle leaves the surface dry by afternoon. Deep infrequent watering suits established plants but kills germinating seed. Matching the shrub program applies water at the wrong frequency entirely.

A residential system is set with a single program watering every zone every day for ten minutes. What is the main weakness of this schedule?

• a.The master valve cycles too often and will wear prematurely
• b.Zones will overlap and reduce pressure at the far heads
• c.Every hydrozone receives the same depth regardless of its need✓
• d.Total runtime exceeds what most controllers can store

A uniform daily schedule ignores the differences between turf, shrubs, and drip areas, so some plants are drowned while others stay dry, which is precisely what hydrozoning and separate programs exist to solve. Storage capacity is not a limit at this scale. Master valve cycling is normal wear. Controllers run stations sequentially, so overlap does not occur.

A rain shutoff device is installed but the system still runs during a storm. What should be checked first?

• a.Whether the sensor is wired into the circuit and not bypassed at the controller✓
• b.Whether the controller has enough stations for the sensor
• c.Whether the sensor is mounted below the roof eave for protection
• d.Whether the sensor is rated for the local reference evapotranspiration

Most controllers have a sensor bypass switch or a jumper that must be removed, and a sensor that is installed but bypassed does nothing, so the wiring and bypass setting are the first check. Station count is unrelated. Sensors are not rated to evapotranspiration values. Mounting under an eave is in fact wrong, because the sensor then never gets wet.

Turf on a narrow parkway strip between the curb and sidewalk shows chronic dry edges and stained concrete. What is the durable fix?

• a.Add two more spray heads and shorten the run time
• b.Convert the strip to subsurface drip with low water use plants✓
• c.Change the nozzles to a higher precipitation rate set
• d.Raise the heads and increase operating pressure at the valve

A narrow strip cannot be watered by overhead spray without overspray, which is why MWELO restricts it, and conversion to subsurface drip with appropriate plants solves both the dry edge and the staining. More heads and higher rates add more water to the pavement. Raising heads and pressure increases both drift and overspray.

Which situation calls for a separate zone rather than adding heads to an existing station?

• a.A lawn panel with a uniform slope of less than two percent
• b.A turf area whose heads are all the same nozzle family
• c.A shaded north-facing bed sharing a valve with full-sun turf✓
• d.A bed whose plants share the same mature size and habit

Shade and full sun produce very different water demand, so combining them on one valve guarantees that one area is mis-watered, and splitting the valve is the fix. Matching nozzle families, uniform plant habit, and a gentle uniform slope are all conditions that make a single shared station work well.

A contractor is asked to add a booster pump because static pressure at the meter is only 38 psi. What must be verified before installing it?

• a.That the pump is installed upstream of the water meter
• b.That the pump is wired to the same circuit as the controller
• c.That the purveyor permits pumping on the service and protection is adequate✓
• d.That the pump discharge exceeds the rating of the mainline pipe

Pumping on a potable service can pull down the main and creates backpressure, so purveyor rules and adequate backflow protection must be confirmed before anything is installed. Sharing a circuit with the controller is an electrical detail. Nothing may be installed upstream of the meter. A pump that exceeds the pipe rating would be a defect rather than a requirement.

At final walkthrough the owner asks for documentation of the new system. Which package is most useful for future maintenance?

• a.The soil report and the plant list from the landscape architect
• b.As-built drawings with valve locations plus the schedule and part list✓
• c.A copy of the hydraulic worksheet used during design
• d.The manufacturer catalog pages for the heads that were used

As-builts showing where valves and mainlines actually landed, together with the programmed schedule and the parts installed, are what a future technician needs to service the system. Catalog pages describe products without locating them. The soil report and plant list support planting decisions. The hydraulic worksheet documents design intent but not field conditions.

A soil report lists 45 percent sand, 35 percent silt, and 20 percent clay. What texture class is that, and what does it mean for irrigation?

• a.Clay loam, which requires frequent shallow irrigation cycles
• b.Silt loam, which holds the most water of any texture class
• c.Loam, which holds moderate moisture and drains at a moderate rate✓
• d.Sandy clay, which drains slowly and needs long soak periods

That mix falls in the loam class, the balanced texture that both retains usable moisture and drains at a workable rate. Sandy clay would need far more clay. Silt loam would need silt to dominate, and even then peats and organic soils hold more water. Clay loam is heavier than these percentages describe and is not watered by frequent shallow cycles.

Two beds are irrigated identically, one in sand and one in clay loam. Why does the sand bed need water more often?

• a.Sand transmits more water upward to the leaf canopy
• b.Sand loses more water to evaporation from the surface
• c.Sand has a higher permanent wilting point than clay loam
• d.Sand holds less available water per foot of soil depth✓

Large pores drain quickly and hold little water against gravity, so sand stores far less plant-available water per foot of depth and empties sooner. Surface evaporation is similar for both when mulched. Clay actually has the higher wilting point because it holds water too tightly to release. Soils do not transmit water to the canopy; roots and the plant do.

A percolation test in a proposed tree pit shows water standing in the hole 24 hours after filling. What does the installer conclude?

• a.The pit should be dug wider so more surface area is exposed
• b.The pit needs additional organic amendment mixed into the backfill
• c.Drainage is inadequate and the planting detail must be changed✓
• d.The soil is within the normal range for a clay site

Water standing a full day means the pit will hold the root ball in saturated soil, so the detail must change, whether by mounding, subdrainage, or moving the tree. Amending backfill in a poorly draining hole creates a bathtub that fills faster. Widening the hole does not give the water anywhere to go. A full day of standing water is a failure, not a normal clay result.

A landscape is failing in a heavy clay pad that was compacted by grading equipment. Which corrective measure addresses the root cause?

• a.Increasing irrigation frequency to keep the surface moist
• b.Ripping the compacted layer and incorporating organic matter✓
• c.Top-dressing with two inches of sand across the pad
• d.Applying a complete fertilizer at twice the label rate

Compaction destroys pore space, so roots and water cannot move, and breaking that layer and blending in organic matter restores structure. Extra fertilizer does not create pore space and can burn stressed roots. More frequent watering keeps a compacted soil saturated. A thin sand layer over clay creates a perched water table rather than drainage.

A soil test returns a pH of 8.1 on a site where azaleas are specified. What is the most practical response?

• a.Apply agricultural lime to buffer the soil before planting
• b.Plant as drawn and correct the pH with monthly acid rinses
• c.Revise the plant list toward species tolerant of alkaline soil✓
• d.Increase the phosphorus rate to offset the high pH

Sustained pH change on an alkaline California soil is slow, expensive, and prone to rebound, so matching the plants to the site is the durable answer. Lime raises pH and would make the problem worse. Extra phosphorus does not change pH and can tie up other nutrients. Monthly acid applications are a maintenance burden that rarely holds.

Which amendment is used to lower the pH of an alkaline landscape soil over time?

• a.Wood ash spread evenly and watered in
• b.Elemental sulfur, which soil bacteria convert to acid✓
• c.Dolomitic limestone worked into the top six inches
• d.Calcium carbonate blended with the backfill

Soil bacteria oxidize elemental sulfur into sulfuric acid, which is the standard way to move pH downward. Dolomitic limestone and calcium carbonate are liming materials that raise pH. Wood ash is strongly alkaline and raises pH as well, so three of these four choices move the soil in the wrong direction.

Newly emerging leaves on a citrus tree are yellow between green veins while older leaves stay dark green. What does this pattern suggest?

• a.Nitrogen deficiency, which appears first on new growth
• b.Phosphorus deficiency from cold soil temperatures
• c.Iron deficiency, common where soil pH is high✓
• d.Potassium deficiency caused by excess irrigation

Iron is immobile in the plant, so a shortage shows on the newest leaves as interveinal chlorosis, and it is common on alkaline California soils where iron is present but unavailable. Nitrogen is mobile and yellows the oldest leaves first and uniformly. Potassium shortage shows as marginal scorch on older leaves. Phosphorus shortage typically shows as dull purpling.

A 50-pound bag is labeled 15-5-10. How much actual nitrogen does the bag contain?

• a.1.5 pounds
• b.3.0 pounds
• c.7.5 pounds✓
• d.5.0 pounds

The first number is percent nitrogen by weight, so 15 percent of 50 pounds is 7.5 pounds. The 1.5-pound figure would come from a 3 percent product. Three pounds would come from a 6 percent product. Five pounds is the phosphate content of this bag expressed the same way, which is a common mix-up.

A specification calls for one pound of actual nitrogen per 1,000 square feet using a 20-0-10 fertilizer. How much product is applied per 1,000 square feet?

• a.10 pounds
• b.20 pounds
• c.2 pounds
• d.5 pounds✓

Dividing the pound of nitrogen wanted by the decimal fraction of nitrogen in the product gives 1 divided by 0.20, or 5 pounds of product. Ten pounds would deliver two pounds of nitrogen. Twenty pounds would deliver four pounds and risk burning. Two pounds delivers only four tenths of a pound and falls short of the specification.

An owner asks why the crew uses a controlled-release fertilizer on a slope above a creek instead of a soluble product.

• a.It contains more total nutrient per bag and covers more ground
• b.It changes soil pH less than soluble products do
• c.It releases gradually, lowering burn risk and leaching✓
• d.It costs less per pound of nitrogen than soluble fertilizer

A coated or slow-release product meters nutrient out over weeks, so less is available to wash off in a storm and less is present at any moment to burn roots, which matters directly above a waterway. Analysis per bag is usually lower rather than higher. Both types can affect pH depending on nitrogen source, and slow-release costs more per pound of nitrogen.

Fresh wood chips are tilled into a planting bed and the plants yellow within weeks. What happened?

• a.The chips held water and drowned the shallow feeder roots
• b.The chips raised soil pH beyond the range the plants tolerate
• c.The chips released natural herbicides that damaged the roots
• d.Microbes decomposing the chips tied up available soil nitrogen✓

High-carbon material incorporated into soil feeds a microbial bloom that immobilizes nitrogen while it decomposes, and the plants go hungry until the process finishes. Wood chips do not shift pH sharply. Allelopathic effects are limited to a few species and not the general case. Chips tilled in improve aeration rather than causing saturation.

How should the same wood chips be used so that nitrogen tie-up is not a problem?

• a.Left on the surface as mulch rather than incorporated✓
• b.Composted for two weeks and then tilled in at six inches
• c.Applied with a high-phosphorus starter fertilizer at planting
• d.Blended at no more than ten percent by volume into backfill

Tie-up happens where carbon and soil are mixed, so leaving chips on top confines the effect to a thin surface layer while the mulch still suppresses weeds and holds moisture. Two weeks is not enough composting. Even ten percent by volume still incorporates raw carbon. Phosphorus does not substitute for the nitrogen the microbes take.

What does MWELO require of a project regarding soil before the planting plan is finalized?

• a.A geotechnical report establishing the bearing capacity of the subgrade
• b.A record of the last three crops or land uses on the parcel
• c.A soil management report with testing and amendment recommendations✓
• d.A certified laboratory analysis of the irrigation water source

MWELO requires a soil management report so that amendment and mulching decisions are based on actual soil chemistry and texture rather than habit. Water quality analysis is useful but is not the required report. Bearing capacity belongs to structural design. Prior cropping history is not part of the ordinance.CA MWELO (Title 23)

MWELO sets a minimum mulch depth on exposed soil in planting areas. Which statement matches the requirement?

• a.Two inches, applied everywhere including turf areas
• b.Four inches, with the layer piled against trunks to hold moisture
• c.At least three inches, with turf and creeping groundcover excepted✓
• d.One inch, refreshed each time the landscape is fertilized

The ordinance calls for a minimum three-inch layer on exposed soil in planting areas and recognizes that turf, rooting groundcover, and direct-seeded areas cannot be mulched that way. Two inches falls short of the minimum. Four inches piled against trunks invites collar rot. One inch neither suppresses weeds nor conserves moisture.CA MWELO (Title 23)

Why must organic mulch be pulled back from the trunk of a newly planted tree?

• a.Mulch against the trunk prevents the root flare from taking up nitrogen
• b.Constant moisture against the bark encourages crown and collar rot✓
• c.Mulch against the trunk raises the soil pH in the root ball
• d.Mulch against the trunk attracts beneficial insects away from the canopy

Bark is not built to stay wet, and mulch heaped against it holds moisture that leads to collar rot and encourages rodents and adventitious roots. Insects are not the driving issue. The flare does not take up nitrogen. Mulch has little effect on pH within the root ball, and none of that would justify burying the trunk.

A five-gallon shrub comes out of the can with roots circling tightly around the outside of the root ball. What should the installer do?

• a.Plant it as is so the intact root ball is not disturbed
• b.Prune the top by a third to balance the restricted roots
• c.Score or tease the circling roots apart before backfilling✓
• d.Set it two inches deeper so the circling roots are covered

Circling roots continue to circle and eventually girdle the plant, so cutting or teasing them outward at planting is required. Planting as is preserves the defect. Pruning the top does not correct roots. Planting deeper buries the root crown, adds a second problem, and still leaves the circling roots in place.

What is the correct relationship between the root flare of a new tree and the surrounding finish grade?

• a.The flare is covered by four inches of amended backfill
• b.The flare is set level with the bottom of the watering basin
• c.The flare sits two inches below finish grade
• d.The flare sits at or slightly above finish grade✓

Planting with the flare at or slightly above grade keeps the trunk base dry and is the single most common difference between trees that establish and trees that decline. Setting the flare below grade or burying it under backfill traps moisture against the bark. A basin bottom sits below grade, so matching it would bury the flare as well.

Current practice for backfilling a tree pit in average native soil is which of the following?

• a.Backfill with imported topsoil to the full depth of the pit
• b.Backfill with native soil below and pure compost in the top foot
• c.Backfill with a fifty-fifty blend of native soil and nursery compost
• d.Backfill with the native soil that came out of the hole✓

Backfilling with native soil encourages roots to move out into the surrounding profile instead of staying in a rich pocket, and it avoids the texture interface that stalls water movement. Heavy compost blends, imported topsoil, and a compost cap all create that interface and can leave the tree rooted only inside the hole.

How wide should a planting hole be relative to the root ball, and why?

• a.Two to three times as wide, so loosened soil eases root spread✓
• b.Half again as wide, so amendment can be layered around the ball
• c.The same width, so the ball is held firmly on all sides
• d.Four times as wide, so a full drainage envelope can be created

A wide shallow hole gives new roots loosened soil to grow into laterally, which is where feeder roots actually go, and two to three times the ball width is the accepted range. A tight hole leaves compacted walls. Layering amendment around the ball creates a texture interface. Four times the width is unnecessary excavation with no added benefit.

A balled-and-burlapped tree arrives in a wire basket with synthetic burlap. What is the correct handling at planting?

• a.Leave the wrapping intact, since both materials break down in soil
• b.Set the tree, then cut away the upper basket and synthetic burlap✓
• c.Cut the burlap only at the top and leave the basket untouched
• d.Remove the basket entirely before the tree is set in the hole

Handling by the ball keeps it intact, so the tree is set first and the upper basket and all synthetic burlap are then cut away, since synthetic burlap never rots and wire can girdle roots. Leaving the wrapping intact assumes a decomposition that does not happen. Removing the basket before setting risks breaking the ball. Cutting burlap alone leaves the wire in place.

Two stakes are installed on a new tree. What describes correct staking?

• a.Ties pulled tight so the trunk cannot flex in any direction
• b.Ties placed just below the lowest branch and left for three seasons
• c.Stakes driven through the root ball for maximum holding power
• d.Ties placed low, allowing some trunk movement, removed within a year✓

Trunk movement builds taper and strength, so ties go low, stay loose, and come off once the tree anchors, usually inside a year. Tying high and leaving stakes for years produces a weak whippy trunk. Stakes driven through the ball damage roots. Rigid ties prevent the very movement that develops trunk strength.

In most of California, which season generally gives the best establishment for woody landscape plants?

• a.Late winter, when plants are fully dormant and shipping is easiest
• b.Midsummer, when nursery stock is fully hardened off
• c.Fall, when soil is still warm and winter rain follows✓
• d.Late spring, when soil has warmed and growth is rapid

Fall planting lets roots grow into warm soil while cool weather and coming rain reduce demand on the canopy, so plants enter their first summer established. Late spring gives only weeks before heat arrives. Midsummer planting stresses new roots hardest. Deep winter works for bare root stock but leaves cold soil and slow root activity for most container plants.

A shrub shows wilted foliage, and the soil around it is wet and smells sour. What is the most likely diagnosis?

• a.Transplant shock from root disturbance at installation
• b.Root rot from saturated soil starving roots of oxygen✓
• c.Drought stress that will resolve after one deep watering
• d.Salt burn from fertilizer applied at too high a rate

Roots need oxygen, and in saturated soil they suffocate and rot, which produces wilting that looks like drought while the soil is wet and smells anaerobic. Adding water makes it worse rather than better. Salt burn shows as marginal leaf scorch in dry soil. Transplant shock does not produce sour saturated soil.

A soil analysis reports a high electrical conductivity and a history of irrigation with hard well water. What management practice is indicated?

• a.Till the top foot to blend the salts through the profile
• b.Apply extra water periodically to leach salts downward✓
• c.Increase nitrogen so plants outgrow the salt injury
• d.Reduce irrigation volume so fewer salts arrive in the soil

Salts accumulate as water evaporates, and the only way to remove them is to move them downward with water applied beyond plant demand, provided the soil drains. Reducing irrigation concentrates salts further. Nitrogen fertilizer is itself a salt and adds to the load. Tilling redistributes salts without removing any of them.

Gypsum is recommended for a soil that has high sodium and poor structure. How does it work?

• a.It adds organic matter that binds soil particles together
• b.It increases the clay fraction so the soil holds more water
• c.It lowers soil pH directly by releasing free acid
• d.Calcium displaces sodium on clay particles so they can aggregate✓

Gypsum supplies calcium that exchanges with sodium on clay surfaces, letting particles flocculate into crumbs so water and air can move; the displaced sodium then leaches. It is neutral and does not lower pH the way sulfur does. It contains no organic matter and does not change the texture class of the soil.

A crew applies gypsum to a compacted clay pad that has normal sodium levels. What result should be expected?

• a.Slow improvement, because gypsum must first lower soil pH
• b.Rapid improvement, because gypsum increases infiltration on any soil
• c.Little improvement, because the problem is compaction not sodium✓
• d.Marked improvement, because gypsum loosens all clay soils

Gypsum corrects sodium-affected soils, and where sodium is not elevated it does very little, so the compacted pad still needs mechanical loosening and organic matter. It is not a general clay loosener, it does not raise infiltration on non-sodic soils, and it is not a pH-lowering material.

MWELO gives a compost incorporation rate for landscape areas where the soil report does not specify otherwise. Which statement reflects it?

• a.Six cubic yards per 1,000 square feet incorporated to a twelve-inch depth
• b.Two cubic yards per 1,000 square feet spread and left on the surface
• c.One cubic yard per 1,000 square feet worked into the top three inches
• d.Four cubic yards per 1,000 square feet incorporated to a six-inch depth✓

The ordinance default is four cubic yards of compost per 1,000 square feet of permeable area worked to a depth of six inches. One cubic yard at three inches is too little to change soil behavior. Compost left on the surface is mulch rather than incorporation. Six cubic yards to a foot exceeds what the ordinance requires and is rarely practical.CA MWELO (Title 23)

What is the primary long-term benefit of adding compost to a landscape soil?

• a.It builds structure, improving both water holding and aeration✓
• b.It supplies a high concentration of immediately available nitrogen
• c.It raises soil pH into the optimum range for most landscape plants
• d.It permanently changes the soil texture class toward loam

Compost feeds soil biology and builds aggregates, which improves water retention in sand and drainage in clay at the same time. Its nutrient release is slow and modest rather than concentrated. Texture is set by particle size and does not change with amendment. Effects on pH depend on the feedstock and are not a reliable benefit.

A designer is selecting turf for a full-sun sports lawn in the Central Valley that will go dormant in winter. Which choice fits?

• a.Creeping bentgrass, used on closely mown putting surfaces
• b.Perennial ryegrass, used mainly for quick cool-season cover
• c.Tall fescue, a cool-season grass that stays green in winter
• d.Hybrid bermudagrass, a warm-season grass that takes wear✓

Hybrid bermudagrass thrives in Central Valley heat, tolerates traffic, and naturally goes off-color in winter, which the owner has accepted. Tall fescue and perennial ryegrass are cool-season grasses that hold winter color rather than going dormant. Creeping bentgrass demands intensive management and is not a general sports surface.

A bermudagrass lawn is overseeded with perennial ryegrass in October. What is the purpose?

• a.To provide green cover while the bermudagrass is dormant✓
• b.To lower the water requirement of the lawn through winter
• c.To crowd out broadleaf weeds permanently from the stand
• d.To thicken the bermudagrass stand before it breaks dormancy

Overseeding puts a temporary cool-season grass over dormant warm-season turf so the lawn stays green until spring. It does not thicken the bermudagrass itself and in fact competes with it in spring. Water use goes up rather than down, and while dense cover suppresses weeds seasonally, the effect ends when the ryegrass fades.

A maintenance contract specifies the one-third rule for mowing. What does it require?

• a.Mowing height is lowered by one third going into summer
• b.No more than one third of the lawn is mowed in any single visit
• c.No more than one third of the leaf blade is removed at a cutting✓
• d.Clippings covering more than one third of the surface are removed

Removing more than a third of the blade at once strips the plant of the tissue that feeds root growth and causes scalping and thinning, so cutting height and frequency are set to stay within that limit. The rule is about blade removal, not the share of area mowed, not a seasonal height change, and not clipping cleanup.

A heavily used lawn drains poorly and the soil is hard underfoot. Which practice most directly relieves the condition?

• a.Top-dressing with a quarter inch of fine sand
• b.Core aeration that removes plugs and opens the profile✓
• c.Vertical mowing to cut through the accumulated thatch layer
• d.Raising the mowing height by half an inch

Core aeration pulls soil plugs out and leaves open channels for air, water, and roots, which is the direct remedy for compaction. Vertical mowing addresses thatch at the surface rather than compaction below it. Sand top-dressing smooths and amends slowly. A higher cut reduces stress but does not open compacted soil.

Sod is being laid on a prepared grade. Which installation practice is correct?

• a.Lay the sod on dry soil so the pieces do not slide out of line
• b.Stagger the joints in a running bond and butt the edges tightly✓
• c.Align all joints in straight rows so the seams disappear
• d.Leave a half inch between pieces so the roots can spread

Staggered, tightly butted joints keep the seams from drying out and knitting poorly, which is the usual cause of a checkerboard lawn. Gaps between pieces dry and fill with weeds. Continuous aligned joints create channels that erode and stay visible. Sod is laid on moist soil, since dry soil pulls water out of the new roots.

Why is new sod rolled lightly and watered immediately after installation?

• a.To press out air that would otherwise encourage disease
• b.To level the surface so the first mowing is uniform
• c.To ensure root contact with soil and prevent drying out✓
• d.To compact the soil below and reduce future settlement

Sod roots only where the mat touches moist soil, so light rolling closes air gaps and immediate water keeps thin roots from desiccating during the first days. Compacting the subsoil would work against rooting. Surface leveling is done during grading. Trapped air is a rooting problem rather than a disease mechanism.

A client wants a lawn established at the lowest material cost and can wait for coverage. Which method fits?

• a.Sprigging, which suits only certain warm-season grasses
• b.Seeding, which costs least but needs careful watering✓
• c.Sod, which gives an instant usable surface
• d.Hydroseeding, which is used mainly for large sloped areas

Seed has the lowest material cost and the client has accepted the wait, though it demands attentive irrigation while it germinates. Sod is the fastest and the most expensive. Sprigging is limited to grasses that spread vegetatively. Hydroseeding suits large or steep areas where broadcasting is impractical and costs more than plain seeding.

A crew is pruning a large limb from a mature tree. Where should the final cut be made?

• a.Leaving a six-inch stub that will drop off naturally
• b.Flush with the trunk so the wound closes smoothly
• c.At the midpoint of the limb to reduce weight first
• d.Just outside the branch collar so the tree can seal it✓

The branch collar contains the tissue that seals the wound, so the final cut goes just outside it. A flush cut removes that tissue and opens the trunk to decay. A long stub cannot be sealed and dies back. Reducing weight at the midpoint is a preliminary step in the three-cut method, not the final cut.

Why is the three-cut method used when removing a heavy limb?

• a.It prevents the falling limb from tearing bark down the trunk✓
• b.It allows the cut to be made without a chainsaw
• c.It reduces the diameter of the final cut by about half
• d.It leaves a stub that protects the wound through winter

An undercut and a relief cut let the weight drop away before the final cut, so the limb cannot peel a strip of bark off the trunk as it falls. The method has nothing to do with the type of saw. Any stub left by the second cut is removed by the third. The final cut diameter is set by the limb, not the method.

A client asks the crew to top a large shade tree to reduce its height. What is the professional response?

• a.Top it during dormancy when the tree can best tolerate the cuts
• b.Top it as requested but seal the cuts to prevent decay
• c.Decline topping and offer crown reduction to appropriate laterals✓
• d.Top no more than half the leaders and revisit the rest next year

Topping leaves stubs that decay and forces weakly attached sprouts, so accepted practice is to decline it and reduce the crown by cutting back to laterals large enough to assume the terminal role. Wound sealers do not prevent decay. Dormant timing does not make topping acceptable, and topping only half the leaders still produces the same defect.

What is the general limit on how much live crown should be removed from an established tree in a single season?

• a.Up to about half, if the tree is vigorous and well watered
• b.No more than about a quarter, to protect the food-producing canopy✓
• c.Up to about two thirds, if structural correction is needed
• d.No more than about ten percent, on any tree of any age

Leaves make the tree's food, so removing more than roughly a quarter of the live crown at once starves it and triggers stress sprouting. Half or two thirds is well past the point where decline begins even on vigorous trees. A ten percent ceiling is stricter than accepted practice and would make routine structural pruning impossible.

An aphid population appears on a hedge with lady beetles already present. Under integrated pest management, what is the reasonable first action?

• a.Apply a systemic soil drench as a preventive treatment
• b.Monitor and wash the aphids off, preserving the natural predators✓
• c.Apply a broad-spectrum insecticide to the entire hedge and surrounding beds
• d.Remove and dispose of every infested shoot on the hedge

Integrated pest management starts with the least disruptive effective action, and lady beetles already at work will often finish the job if they are not killed. A broad-spectrum spray removes the predators and invites a rebound. A preventive systemic drench treats a problem that may not develop. Stripping the shoots removes the plant along with the pest.

Sticky residue and black sooty coating appear on the leaves under a tree. What is the likely sequence?

• a.Hard irrigation water is leaving mineral residue on the foliage
• b.Sap-feeding insects excrete honeydew, and mold grows on the honeydew✓
• c.Air pollution is depositing particulates that stick to leaf surfaces
• d.A soil-borne fungus is moving up the trunk into the canopy

Aphids, scale, and whitefly excrete sugary honeydew, and sooty mold colonizes that film, so controlling the insect resolves both. A soil-borne fungus does not produce a sticky surface deposit. Mineral residue from hard water is white and chalky rather than black and sticky. Particulate deposition does not create a sticky sugar film.

Fine stippling and light webbing appear on shrubs beside a dusty driveway during a hot dry spell. Which pest is most likely?

• a.Spider mites, which increase in hot dry dusty conditions✓
• b.Thrips, which distort new growth as it expands
• c.Root weevils, which notch leaf margins at night
• d.Leafminers, which tunnel between the leaf surfaces

Spider mites build up in heat and dust and produce a stippled, faded leaf with fine webbing. Leafminers leave visible tunnels inside the leaf rather than surface stippling. Root weevils leave notched margins. Thrips cause silvering and distortion of expanding tissue, and neither weevils nor thrips spin webbing.

A pre-emergent herbicide is specified for a shrub bed. When must it be applied to work?

• a.At any point in the season, since it kills weeds on contact
• b.Before weed seeds germinate, then watered in to form a barrier✓
• c.Only after the bed has been cultivated to expose the seed bank
• d.After the weeds have emerged but before they set seed

A pre-emergent works on germinating seedlings, so it must be in place and activated by water before germination begins. Applying after emergence is too late because the product does not kill established weeds. It is not a contact material. Cultivating after application breaks the treated layer and undoes the barrier.

Bermudagrass is invading a shrub bed from the adjoining lawn. Which control approach is most durable?

• a.A pre-emergent applied twice a season along the edge of the bed
• b.A contact herbicide applied to the foliage on a warm day
• c.Hand pulling the visible runners each maintenance visit
• d.A physical edge barrier plus systemic control of the rhizomes✓

Bermudagrass spreads by rhizomes and stolons, so lasting control needs a barrier that stops lateral spread plus a systemic material that moves into the underground parts. Pre-emergents stop seed but not rhizome growth. Hand pulling breaks runners and leaves the rhizomes. A contact herbicide burns the top and the plant regrows.

A plant list is being reviewed for water efficiency on a Sacramento site. Which approach is most defensible?

• a.Select only plants native to the immediate watershed of the site
• b.Select species that stay under three feet so less canopy is watered
• c.Select species by regional water use ratings and group them by need✓
• d.Select evergreen species, since deciduous plants use more water

Published regional water use ratings let a designer choose plants that fit the climate zone and then group them into hydrozones that can actually be scheduled. Restricting to a single watershed is narrower than water efficiency requires. Mature size does not determine water use, and evergreen versus deciduous habit is not a reliable predictor either.

Groundcover is specified at 18 inches on center in a 200 square foot bed using triangular spacing. Compared with square spacing at the same interval, triangular spacing does what?

• a.Uses more plants and closes the bed more evenly✓
• b.Uses fewer plants but requires a wider border row
• c.Uses fewer plants and closes the bed more slowly
• d.Uses the same count but arranges plants in offset rows

Offsetting each row places plants closer to their diagonal neighbors, so a triangular layout fits more plants into the same area and fills in with fewer gaps. It does not reduce the count, and the count is not the same as square spacing at the same interval. Border treatment is a detail that does not change the underlying density.

What should determine the spacing between shrubs in a new foundation planting?

• a.The reach of the irrigation heads serving the bed
• b.The mature spread of the species being planted✓
• c.The width of the bed as drawn on the plan
• d.The size of the container the plants arrive in

Plants grow into their mature spread, so spacing set from that dimension avoids the crowded, sheared hedge that a tight installation becomes. Container size reflects nursery production rather than mature form. Bed width sets how many rows fit, not the interval. Irrigation layout should follow the planting design, not drive it.

A designer places a 40-foot shade tree eight feet from a two-story wall on the south side. What is the main problem?

• a.The mature canopy and roots will conflict with the structure✓
• b.The tree will need staking permanently because of wind eddies
• c.The tree will shade the wall and encourage mildew on the siding
• d.The wall will reflect heat and dry the root zone excessively

A tree with a wide mature canopy set eight feet from a wall will grow into the building and send structural roots under the footing area, which is a spacing failure that no maintenance can fix. Reflected heat, shading, and wind eddies are real site factors but are secondary to placing a large tree far too close to a structure.

During grading, fill soil is proposed to a depth of one foot over the root zone of a protected oak. What is the concern?

• a.Fill raises the pH of the root zone beyond what oaks tolerate
• b.Fill increases the weight the trunk must support during wind
• c.Fill reduces the amount of rainfall reaching the drip line
• d.Fill smothers roots by cutting off oxygen exchange at the surface✓

Tree roots respire, and a foot of fill blocks the gas exchange the surface roots depend on, which is why fill over root zones kills mature oaks slowly. Fill does not reliably change pH. Soil weight is carried by the ground, not the trunk. Rain still reaches the area, and moisture is not the mechanism of decline.

Where should the protective fencing be placed when a tree must be preserved through construction?

• a.At or beyond the drip line of the tree canopy✓
• b.Along the property line nearest the tree
• c.Three feet out from the trunk on every side of the tree
• d.At the edge of the proposed hardscape only

Most absorbing roots lie in the upper soil out to and past the canopy edge, so fencing at or beyond the drip line is what actually keeps equipment off them. A three-foot ring protects the trunk and almost none of the roots. Property lines and hardscape edges are unrelated to where the root system lies.

A bare-root rose arrives in January. What handling is correct before planting?

• a.Wrap the roots in plastic and hold it at room temperature
• b.Store it in full sun so the canes begin to break dormancy
• c.Keep the roots moist and shaded, and plant while still dormant✓
• d.Prune the roots back by half so they fit the planting hole

Bare-root stock has no soil to buffer it, so the roots must stay moist and cool and go in the ground while the plant is still dormant. Sun exposure breaks dormancy and dries the roots. Sealed plastic at room temperature encourages mold and heating. Cutting roots to fit removes the plant's stored resources; the hole is enlarged instead.

A hydroseed mix for a slope includes seed, fertilizer, wood fiber mulch, and a tackifier. What does the tackifier contribute?

• a.It dyes the slurry so the operator can see the coverage
• b.It supplies the nitrogen the seedlings use during germination
• c.It binds the slurry to the slope so it resists rain and wind✓
• d.It holds moisture at the seed until the first true leaves appear

A tackifier is a binder that glues the fiber and seed to the surface so a storm does not wash the application off. Nitrogen comes from the fertilizer in the mix. The green dye is a separate tracer component. Moisture retention is largely a function of the wood fiber mulch rather than the binder.

A landscape is being converted from lawn to a low water use planting. What preparation step most affects long-term success?

• a.Adding sand across the area to improve drainage before planting
• b.Applying a high-nitrogen fertilizer to the whole area at conversion
• c.Leaving the old sprinkler heads in place as backup irrigation
• d.Killing or removing the existing turf and its rhizomes completely✓

Surviving turf rhizomes will grow through a new planting for years, so full removal or kill is the step that determines whether the conversion holds. Sand over an existing soil creates a texture interface rather than drainage. High nitrogen pushes weed growth. Abandoned spray heads left in a drip conversion become leaks and confusion.

A soil report gives an infiltration rate of 0.15 inches per hour. What does that number govern in the design?

• a.The application rate the irrigation system may use without runoff✓
• b.The number of plants that can be supported per hundred square feet
• c.The total depth of water the root zone can store
• d.The depth to which compost should be incorporated

Infiltration rate is how fast soil accepts water, so it sets the ceiling on precipitation rate before runoff begins and drives the choice of low-rate nozzles or cycle-and-soak. Storage capacity is a different property tied to texture and depth. Plant density comes from mature size. Amendment depth is a specification, not a function of intake rate.

What does the term field capacity describe?

• a.The total pore volume of a soil sample when fully saturated
• b.The soil moisture level at which plants can no longer extract water
• c.The moisture a soil holds after free drainage has stopped✓
• d.The moisture content at which a soil can be safely compacted

Field capacity is the water remaining after gravity has drained the large pores, and it is the upper end of the plant-available range. The point where plants can no longer extract water is the permanent wilting point. Total pore volume at saturation is a different measure. Optimum moisture for compaction is a construction property, not a plant-water term.

Why does deep, infrequent irrigation generally produce healthier established plants than daily light watering?

• a.It lowers salt concentration in the upper few inches of soil
• b.It wets the full root zone and encourages roots to grow deeper✓
• c.It reduces the total volume of water the landscape consumes
• d.It keeps soil temperature more stable through the growing season

Water only reaches the depth it is applied to, so deep cycles draw roots downward into a larger reservoir while daily sprinkles keep roots shallow and dependent. Total volume depends on the schedule, not the pattern. Soil temperature is affected mainly by mulch and season. Deep watering can move salts down but that is a side effect rather than the main mechanism.

A newly planted landscape is on the same schedule as the mature planting next door and the new plants are struggling. What is the likely reason?

• a.New plants require more fertilizer than the mature planting receives
• b.New root balls dry faster and need their own establishment schedule✓
• c.New plants need a lower mowing and pruning frequency than mature ones
• d.New plants are more sensitive to the mineral content of the water

A fresh root ball holds a small volume of nursery mix that dries far faster than surrounding soil, so new plantings need a separate, more frequent establishment schedule until roots move outward. Fertilizer, water mineral content, and maintenance frequency all matter less than the mismatch between a small root ball and a mature-planting schedule.

A shrub was planted three inches too deep two years ago and is now declining. What is the appropriate correction?

• a.Cut the top back by half to balance the buried root system
• b.Increase fertilizer and irrigation to push new growth
• c.Install a drainage sump beside the plant to draw water away
• d.Excavate the excess soil back to expose the root crown✓

A buried crown stays wet and rots, so removing the excess soil to expose the crown is the direct fix. More fertilizer and water push growth onto a failing root system. Cutting the top back removes food production without addressing the burial. A sump drains soil water but does not uncover the crown that is decaying.

An arborist reports Armillaria root disease in a bed where oaks are declining. What management step is most relevant to the C-27 contractor?

• a.Apply a broad-spectrum fungicide drench across the entire bed
• b.Reduce summer irrigation near the trunks and improve drainage✓
• c.Replant the same species and treat the backfill before installation
• d.Increase irrigation frequency to reduce stress on the remaining trees

Armillaria advances in wet soil around the root crown, so cutting summer water near trunks and improving drainage is the practical control available on site. Soil fungicide drenches do not reliably reach the fungus. Adding water encourages it. Replanting susceptible species into infested soil repeats the failure.

Which condition best describes when a bed is ready for finish raking and planting?

• a.The soil has been rolled to remove all surface texture
• b.The soil is moist but crumbles rather than smearing when squeezed✓
• c.The soil is wet enough that it ribbons between the fingers
• d.The soil is dry enough that it powders under the rake

Soil worked at the crumbly moist stage keeps its structure, while soil worked wet smears into clods and soil worked bone dry turns to dust and blows away. A soil that ribbons is too wet to work. Rolling out all surface texture seals the soil and reduces the infiltration a new planting depends on.

A specification calls for six inches of imported topsoil over a native clay subgrade. What must be done at the interface?

• a.Place two inches of gravel between the layers to promote drainage
• b.Place a filter fabric between the layers to keep them separate
• c.Scarify the subgrade and blend the two soils at the boundary✓
• d.Compact the subgrade to a smooth sealed surface before placing topsoil

A sharp change in texture stalls water movement, so scarifying and blending at the boundary lets water and roots cross it. A sealed compacted subgrade guarantees a perched water table. Fabric between soil layers is a root and water barrier. A gravel layer between two soils makes the perching worse rather than better.

Turf is specified under the canopy of dense mature trees on the north side of a building. What should the contractor raise with the designer?

• a.That the turf will require a separate backflow assembly
• b.That the trees should be staked before the turf is installed
• c.That the trees will need to be fertilized more heavily
• d.That the shade and root competition make turf a poor fit✓

Deep shade plus tree root competition for water and nutrients keeps most turf thin no matter how it is managed, so a shade-tolerant groundcover or mulch is the better recommendation. Fertilizing the trees does not create light. A backflow assembly serves the whole system rather than one area. Mature trees do not need staking.

A landscape uses ammonium sulfate as its nitrogen source year after year. What effect should be anticipated on soil chemistry?

• a.Soil organic matter increases steadily over time
• b.Soil pH drifts upward toward the alkaline range
• c.Soil pH drifts downward as the material acidifies the soil✓
• d.Soil salinity falls because sulfate leaches other salts

Ammonium sulfate is an acidifying nitrogen source, so repeated use pushes pH down, which can be useful on alkaline soil and harmful where pH is already low. It does not raise pH. It contributes no organic matter. It is a salt itself, so it adds to salinity rather than reducing it.

Older leaves on a hedge are uniformly pale while new growth stays green. Which nutrient is most likely short?

• a.Calcium, which moves only in the transpiration stream
• b.Zinc, which is required in very small amounts
• c.Iron, which is immobile within the plant
• d.Nitrogen, which the plant moves from old leaves to new✓

Nitrogen is mobile, so a deficient plant pulls it out of old leaves to supply new growth, which yellows the oldest foliage first and uniformly. Iron and calcium are immobile and show their symptoms on new growth instead. Zinc shortage produces small distorted new leaves rather than uniform pale older foliage.

A homeowner reports the new lawn is yellowing and says it is watered for 30 minutes every evening. What should the contractor check first?

• a.Whether the mowing height has been lowered too far
• b.Whether the seed variety matches the exposure of the site
• c.Whether the fertilizer applied at installation has been exhausted
• d.Whether the soil is staying saturated and starving roots of air✓

Nightly watering on most soils keeps the profile saturated, and roots without oxygen yellow in a way that looks exactly like a nutrient shortage, so the schedule is the first thing to test with a probe. Mowing height, variety selection, and fertilizer timing are all worth reviewing, but none explains yellowing under a clearly excessive watering pattern.

What is the practical purpose of a soil probe or auger in routine landscape maintenance?

• a.To collect samples for the required soil management report
• b.To measure the pH of the root zone in the field
• c.To determine the compaction percentage of the subgrade
• d.To check how deep applied water actually penetrated✓

Pulling a core after a cycle shows whether water reached the root zone or stopped a few inches down, which is the fastest way to correct a schedule. Field pH requires a test kit or meter. Compaction percentage requires a density test, not a hand probe. Samples for a formal report are collected to a laboratory protocol rather than casually.

A C-27 licensee is asked to build a wood-framed pool house with a bathroom as part of a backyard landscape package. How should the licensee proceed?

• a.Subcontract it to contractors holding the appropriate classifications✓
• b.Build the structure and subcontract only the finish carpentry
• c.Build it if the total value stays under the landscape contract amount
• d.Build it, since it sits within the landscape area being developed

The landscaping classification covers landscape systems and features and the grading that supports them, not habitable structures with plumbing and electrical work, so those trades must be subcontracted to properly licensed contractors. Being inside the landscape area, keeping the framing in house, or comparing dollar values does not extend the classification.16 CCR §832.27

Which of the following is most clearly within the C-27 landscaping classification?

• a.Reroofing a detached garage that faces the new patio
• b.Installing a new subpanel to power landscape lighting
• c.Installing a residential swimming pool and its equipment
• d.Grading and preparing a yard for decorative treatment✓

Preparing and grading plots for horticultural and decorative treatment is expressly part of the landscaping classification. A new subpanel is electrical work, roofing is a separate specialty, and swimming pool construction has its own classification, so each of those must be held or subcontracted separately.16 CCR §832.27

A landscape contract includes low-voltage path lighting fed from an existing exterior receptacle. What is the correct division of work?

• a.An electrical contractor must install every part of a lighting system
• b.The landscape crew adds a new receptacle first, then the transformer
• c.The landscape crew may run 120-volt cable if it stays under 50 feet
• d.The landscape crew sets the transformer and low-voltage runs at that receptacle✓

Plugging a transformer into an existing code-compliant exterior receptacle and running the low-voltage cable is landscape work. Adding a new receptacle or running any new 120-volt cable is electrical work regardless of length. It is also not the case that an electrical contractor must perform the low-voltage portion once the supply already exists.

Finish grade at a house is being set. What is the standard target for surface drainage away from the foundation?

• a.A slight fall toward the wall, drained by a perimeter french drain
• b.A crown at the wall with equal falls in both directions
• c.A fall away from the wall over the first several feet of ground✓
• d.A level pad with a swale at the property line to collect water

Positive fall away from the wall in the first several feet is what keeps water out of the foundation, and every other detail is downstream of it. A level pad ponds against the wall. Sloping toward the wall and relying on a drain fails the moment that drain clogs. Crowning at the wall would require the wall to be the high point of the pad, which it is not.

A patio must drain across its surface to a lawn edge. What cross slope is normally specified?

• a.Zero, with drainage handled by joints between the pavers
• b.About five percent, to move water quickly off the surface
• c.About one quarter percent, so furniture sits level
• d.About one to two percent, roughly an eighth inch per foot✓

Roughly an eighth of an inch per foot moves water reliably without being noticeable underfoot or under furniture. A dead level surface ponds even on permeable paving. A quarter percent is inside construction tolerance and will pond in low spots. Five percent is steep enough to feel and would be uncomfortable for seating.

A grading plan describes a slope as 3:1. Which statement is correct?

• a.The slope rises three feet for each foot of horizontal run
• b.The slope is expressed as a three percent grade
• c.The slope runs three feet horizontally for each foot of fall✓
• d.The slope drops three inches per foot of run

Slope ratios are written horizontal to vertical, so 3:1 means three feet of run for every foot of rise or fall, which is about a 33 percent grade. Reversing the ratio would describe a very steep bank. It is not a three percent grade, and three inches per foot would be a 25 percent grade written differently.

Contour lines on a grading plan are drawn close together across one part of the site. What does that spacing indicate?

• a.The area is proposed for fill rather than cut
• b.The area drains toward the nearest catch basin
• c.The ground is nearly level in that area
• d.The ground is steep in that area✓

Contours mark equal elevations, so a short horizontal distance between them means elevation changes quickly and the ground is steep. Widely spaced contours indicate flat ground. Cut and fill are shown by comparing existing and proposed contours rather than by spacing alone, and drainage direction is read from the shape of the contours, not their closeness.

A designer wants to move surface runoff across a yard without a piped system. Which feature does that?

• a.A shallow vegetated swale graded toward the outlet✓
• b.A dry well set at the low corner of the yard
• c.A french drain laid level along the fence line
• d.A catch basin with a solid lid at the midpoint

A swale is a graded surface channel that carries and slows runoff on its way to an outlet, which is exactly the described need. A dry well stores and infiltrates at one point rather than conveying. A catch basin collects into a pipe. A level french drain has no fall and only intercepts subsurface water where it sits.

A new grading plan would send additional runoff onto the neighboring downhill lot. What is the contractor's obligation?

• a.Install a berm on the neighbor's side to contain the added flow
• b.Design the drainage to an approved outlet off the property✓
• c.Proceed if the neighbor gives verbal permission on site
• d.Proceed, since water naturally flows downhill between properties

Concentrating or increasing runoff onto adjacent property creates liability and usually violates local grading rules, so the work must be designed to an approved point of discharge. Natural flow does not license added flow. Verbal permission is not a substitute for a compliant design, and building anything on the neighbor's land is not the contractor's to do.

Perforated pipe is being installed in a gravel-filled trench to intercept subsurface water. How should it be laid?

• a.Holes down, in washed rock wrapped in filter fabric✓
• b.Holes up, bedded directly on native soil without gravel
• c.Holes to the sides, with the trench wrapped in plastic sheeting
• d.Holes up, so water enters only after the trench fills

Perforations face down so water entering the trench at any depth can get into the pipe immediately, and washed rock with filter fabric keeps fines from silting the system. Holes up delays entry until the trench floods. Plastic sheeting stops the very water the drain is meant to collect. Bedding on native soil without rock plugs the perforations.

What minimum fall is normally used on a landscape drain line so it does not silt up?

• a.About one quarter percent, roughly a thirty-second inch per foot
• b.About five percent, roughly five eighths inch per foot
• c.About one percent, roughly an eighth inch per foot✓
• d.No fall is needed because the pipe flows full under head

Roughly one percent keeps velocity high enough to carry silt through the line without being so steep that water outruns the solids. A quarter percent is too flat to self-clean at landscape flows. Five percent is far more fall than most yards can give and is unnecessary. A gravity drain that is laid flat will silt in.

Downspouts on a house currently discharge onto a planting bed near the foundation. What is the appropriate landscape correction?

• a.Install a dry well directly against the foundation wall
• b.Connect the downspouts to a pipe discharging away from the house✓
• c.Regrade the bed level so water spreads out instead of channeling
• d.Add six inches of mulch under each downspout to absorb the flow

Roof water is concentrated flow and belongs in a pipe that carries it well away from the foundation. Mulch cannot absorb a roof's worth of water. A level bed holds the water against the wall rather than moving it. A dry well set against the foundation deliberately puts infiltration exactly where it does the most harm.

A bioswale is specified on a commercial landscape. What is its main stormwater function?

• a.To slow runoff and filter it through soil and vegetation✓
• b.To provide a lined channel that speeds runoff off the site
• c.To separate irrigation runoff from roof runoff for metering
• d.To store runoff until it can be pumped to the storm drain

A bioswale slows water, lets it soak in, and filters pollutants through the planted soil profile before any overflow leaves the site. It is not a pumped storage basin, and a lined fast channel is the opposite of what it does. Metering separation is a plumbing arrangement, not a swale function.

Aggregate base is being placed for a paver patio. How should it be compacted?

• a.In lifts of about four to six inches at optimum moisture✓
• b.In one lift, wetted thoroughly and compacted from the center outward
• c.In lifts of about twelve inches at optimum moisture
• d.In one lift, compacted dry so the fines do not migrate

Compaction energy only reaches a limited depth, so base goes in lifts of roughly four to six inches at optimum moisture and each lift is compacted before the next. A single thick lift leaves the bottom loose regardless of direction of travel. Dry material will not densify. Twelve-inch lifts exceed what a plate compactor can reach.

Two crews compact the same base material at very different moisture levels and get different densities. What explains this?

• a.Drier material compacts to a higher density in every case
• b.Wetter material compacts to a higher density in every case
• c.Moisture affects only the finish, not the resulting density
• d.Every soil has an optimum moisture content for maximum density✓

Water lubricates particles up to a point and then occupies space that soil would otherwise fill, so each material has an optimum moisture at which density peaks. Wetter is not uniformly better, since saturated material pumps under the compactor. Drier is not uniformly better either, because friction blocks rearrangement. Density is directly affected.

A specification requires 90 percent relative compaction of the subgrade. What is that percentage measured against?

• a.The maximum dry density from a laboratory compaction test✓
• b.The in-place density of undisturbed soil elsewhere on the lot
• c.The percentage of the trench volume filled with backfill
• d.The density of the aggregate base placed over the subgrade

Relative compaction compares field density to the maximum dry density established for that soil in a laboratory test, which is why a sample goes to the lab before the specification means anything. Base density is a separate material. Undisturbed soil nearby is not a standard. The share of trench volume filled is not a density measure at all.

A crew must compact a narrow trench backfill in cohesive clay. Which equipment is best suited?

• a.A water jet, which settles the fill by saturation
• b.A rammer or jumping jack, which delivers impact into cohesive clay soil✓
• c.A vibratory plate compactor, which works granular material well
• d.A smooth drum roller, which covers the length quickly

Cohesive clay responds to impact rather than vibration, so a rammer is the right tool in a narrow trench. Plate compactors are designed for granular material. A drum roller cannot fit or reach the bottom of a trench. Jetting saturates the fill and produces settlement later rather than compaction now.

A paver walkway settles in ruts within one season while the adjacent driveway holds. What is the most likely cause?

• a.The joint sand was not swept in deeply enough
• b.The bedding sand layer was screeded too thin
• c.The base was too shallow or inadequately compacted✓
• d.The pavers were laid in a running bond instead of herringbone

Pavers ride on the base, so ruts and dips almost always trace back to base depth or compaction rather than to the surface course. Joint sand locks pavers together but carries no load. Pattern affects interlock under vehicles more than settlement. Bedding sand should be thin, and a thin screed is correct rather than a defect.

How does base thickness for a paver driveway compare with base thickness for a paver walkway?

• a.The walkway needs the thicker base because it lacks edge restraint
• b.The driveway needs a thicker base because it carries vehicle loads✓
• c.The driveway needs a thinner base because vehicles compact it further
• d.The two are the same because the pavers are the same thickness

Base thickness follows the load, so a drive carrying vehicles needs substantially more base than a pedestrian walk. Paver thickness alone does not set base depth. Walkways carry less load, and every paver field needs edge restraint regardless. Traffic does not usefully compact a base that was undersized to begin with.

Why is a herringbone pattern preferred for pavers in a driveway?

• a.It allows a thinner bedding sand layer to be used
• b.It resists creeping and shifting under turning vehicle loads✓
• c.It reduces the amount of joint sand the field requires
• d.It requires fewer cuts along the perimeter of the field

Herringbone interlocks in two directions, so braking and turning forces cannot push a line of pavers along a continuous joint. It generally requires more perimeter cuts, not fewer. Bedding sand depth is fixed by the screed regardless of pattern, and joint sand quantity varies little between patterns.

What is the correct thickness of the bedding sand layer under interlocking concrete pavers?

• a.About three inches, screeded and compacted before laying
• b.About two inches, screeded loose and left uncompacted
• c.About one inch, screeded loose and left uncompacted✓
• d.No bedding layer, with pavers set directly on the base

Roughly one inch of loose screeded sand is enough to seat the pavers and no more, because a thick sand layer behaves like an uncompacted base and lets the surface rut. Two or three inches is far too much. Compacting the sand before laying defeats its purpose. Setting pavers directly on base leaves no way to level the surface.

Edge restraint is being installed around a paver patio. What does it accomplish?

• a.It seals the field so water cannot enter the joints
• b.It carries the load at the perimeter where the base is thinnest
• c.It keeps perimeter pavers from spreading and losing interlock✓
• d.It provides a level reference for screeding the bedding sand

Without restraint the outer courses migrate outward, joints open, and the interlock that makes the whole field work is lost. Screed rails, not edge restraint, guide the sand. Restraint does not carry vertical load. It also does not seal the field, since paver systems are designed to shed water at the surface rather than to be watertight.

How does the base under permeable pavers differ from the base under standard pavers?

• a.It uses open-graded clean stone that stores and passes water✓
• b.It uses a fines-rich base compacted to a higher density
• c.It uses a thinner base because water does not sit on the surface
• d.It uses the same base with a perforated pipe added at the bottom

Permeable systems are built on open-graded washed stone with large voids so water can pass through and be stored before infiltrating. Adding a pipe to a dense base does not create that void space. The base is usually thicker rather than thinner because it doubles as a reservoir. Fines are exactly what must be kept out.

A permeable paver parking area stops draining after four years. What is the usual cause?

• a.Sediment has clogged the surface joints and must be removed✓
• b.The subgrade has consolidated under repeated vehicle loading
• c.The pavers have absorbed water and swelled against each other
• d.The joint stone has settled and reduced the void space

Permeable systems fail at the surface, where windblown fines and landscape debris seal the joints, and periodic vacuuming restores them. Joint stone settlement is minor by comparison. Subgrade consolidation would show as rutting rather than as ponding. Concrete pavers do not swell enough to close joints.

Control joints are tooled into a new concrete patio. What determines their spacing?

• a.They are placed wherever the pour is interrupted for the day
• b.They are spaced at a fixed twenty feet regardless of slab thickness
• c.They are placed at every change in the color of the finish
• d.Spaced in feet at two to three times the slab thickness in inches✓

A common rule spaces joints in feet at about two to three times the slab thickness in inches, so a four-inch slab gets joints around eight to twelve feet apart. A pause in the pour creates a cold joint, which is a different detail. Finish color is unrelated. A single fixed spacing ignores thickness entirely.

How deep should a control joint be cut or tooled in a concrete slab?

• a.About one half the slab thickness
• b.About one eighth inch regardless of thickness
• c.Through the full thickness of the slab
• d.About one quarter of the slab thickness✓

A joint about a quarter of the slab depth creates a weakened plane deep enough to direct the crack without cutting the slab apart. A full-depth cut makes separate slabs and severs any reinforcement. Half depth is deeper than needed and weakens the section. A shallow scratch will not control where the crack goes.

A new concrete walk will abut an existing building slab. Which joint belongs at that line?

• a.A doweled construction joint tying the two slabs together
• b.An isolation joint with compressible material full depth✓
• c.A tooled control joint matching the pattern of the walk
• d.A saw cut made the following day at the building face

The building and the walk move independently, so a full-depth isolation joint with compressible filler lets that happen without cracking either one. A control joint only guides shrinkage cracking within one slab. Doweling would tie the walk to the structure, which is the opposite of the intent. A late saw cut does not create separation.

A driver arrives with concrete that has been in the truck longer than expected and asks whether to add water. What is the correct answer?

• a.Add water only to the last third of the load being placed
• b.Do not add water beyond the design mix, since strength falls✓
• c.Add water and compensate by finishing the surface more heavily
• d.Add water freely, since workability governs the finish quality

Strength drops as the water to cement ratio rises, so adding water on site to restore workability trades durability for convenience. Limiting the addition to part of the load creates inconsistent concrete. Heavy finishing of a wet mix brings fines and water to the surface and produces a weak, dusting slab.

Why is a new concrete flatwork slab kept moist or covered for several days after placement?

• a.To allow cement hydration to continue and develop strength✓
• b.To prevent the aggregate from settling to the bottom
• c.To keep the surface soft enough for later saw cutting
• d.To keep the surface color uniform as the slab dries

Cement gains strength through hydration, which requires water, so curing keeps moisture in the slab while that reaction proceeds. Color uniformity is a finishing matter. Aggregate segregation happens during placement, not during curing. Saw cutting is timed to the concrete's set and is not the reason for curing.

A segmental retaining wall is planned at five feet exposed height on a residential lot. What should the contractor expect?

• a.A permit and an engineered design from the local jurisdiction✓
• b.No permit, since the wall retains only landscape soil
• c.No permit, since segmental walls are not structures
• d.A permit only if the wall is closer than five feet to the property line

Most California jurisdictions require a permit and engineered design once a retaining wall passes roughly four feet or carries a surcharge, and a five-foot wall is squarely in that range. Segmental construction does not exempt a wall, retaining landscape soil is still retaining, and proximity to a property line is a separate setback question.

A retaining wall is designed with a driveway directly behind it. What does that condition add to the design?

• a.A requirement for a taller leveling pad under the first course
• b.A requirement to omit drainage rock so the base stays firm
• c.A surcharge load that must be accounted for by the engineer✓
• d.A reduction in the geogrid length because the drive confines the soil

Vehicles and pavement behind a wall impose a surcharge that increases the force the wall must resist, and the engineer must design for it. Drainage rock is more important with a surcharge, not less. Pad height is not the response to added load, and geogrid usually needs to be longer rather than shorter to reach beyond the loaded zone.

Why is the first course of a segmental block wall normally set below finish grade in front of the wall?

• a.To reduce the number of blocks needed in the wall face
• b.To hide the leveling pad from view along the base
• c.To allow the drain pipe to be placed above the first course
• d.To resist sliding and prevent undermining at the toe✓

Burying the base course gives passive resistance at the toe and protects it from erosion, which is why the detail is standard rather than cosmetic. Appearance is a side benefit. The drain typically sits behind the base course, not above it, and burying a course adds blocks rather than saving them.

A block wall leans outward after the first wet winter and the drain outlet has never flowed. What most likely occurred?

• a.The leveling pad was placed too deep below finish grade
• b.The wall was built with too much batter toward the retained soil
• c.Hydrostatic pressure built behind the wall as drainage failed✓
• d.The blocks absorbed water and expanded against one another

Water trapped behind a wall pushes with far more force than the soil alone, so a blocked or missing drain is the classic cause of a wall that leans after a wet season. Concrete blocks do not expand meaningfully. A deeper pad increases stability. Batter leaning into the slope resists failure rather than causing it.

What is the correct backfill immediately behind a segmental retaining wall?

• a.Native clay compacted in six-inch lifts against the block
• b.Topsoil, so plantings on the terrace above can root freely
• c.Clean drainage rock with a perforated pipe and filter fabric✓
• d.Sand, so water passes quickly through to the subgrade

A drainage chimney of clean rock with a collector pipe and fabric moves water out before it can load the wall. Clay against the block traps water and swells. Topsoil holds moisture and fines. Sand passes water but carries fines and clogs, which is why washed rock and fabric are specified together.

Geogrid is specified in a taller segmental wall. What does it do?

• a.It reinforces the retained soil mass so it acts with the wall✓
• b.It carries water from the drainage rock to the wall outlets
• c.It reinforces the block face against impact from the front
• d.It separates the base course from the leveling pad below

Geogrid layers extend back into the fill and tie the soil into a reinforced mass that behaves as one body with the facing blocks. It is not a facing reinforcement, it is not a drainage layer, and separation between the pad and the base course is neither needed nor its function.

A garden wall on expansive clay cracks in the same places every year. What soil behavior explains it?

• a.The clay conducts heat and expands the wall units themselves
• b.The clay consolidates permanently under the weight of the wall
• c.The clay dissolves during winter rain and loses bearing capacity
• d.The clay swells when wet and shrinks when dry, moving footings✓

Expansive clay changes volume with moisture content, lifting and dropping footings seasonally, which is why the same cracks reopen each year. Consolidation is a one-way settlement rather than a seasonal cycle. Clay does not dissolve, and thermal movement of the block units is far too small to produce this pattern.

A dry-stacked mortarless block wall is proposed at 30 inches high with level ground behind it. What primarily holds it in place?

• a.The steel reinforcement grouted through the block cores
• b.The friction of the topsoil placed against the back face
• c.The mass of the units, their setback, and the compacted base✓
• d.The mortar bond between the block courses

A low gravity wall stands on its own weight, the batter that leans it into the slope, and a properly compacted leveling pad. There is no mortar or grouted steel in a dry-stack system, which is what makes those details critical, and loose topsoil behind the wall provides no meaningful restraint.

Steps are being laid out on a garden slope. Which riser and tread combination is most comfortable for outdoor use?

• a.A 9-inch riser with a 12-inch tread
• b.A 4-inch riser with a 10-inch tread
• c.An 8-inch riser with a 9-inch tread
• d.A 6-inch riser with a 14-inch tread✓

Outdoor steps use lower risers and deeper treads than interior stairs, and roughly six inches with a fourteen-inch tread fits the common relationship of two risers plus a tread near 26 inches. An eight by nine step is an interior proportion. A four-inch riser with a ten-inch tread is awkwardly shallow. A nine-inch riser is too tall for garden use.

An accessible route is being built through a commercial landscape. What is the maximum cross slope generally allowed on the walking surface?

• a.About one twelfth, or 8.33 percent
• b.About two percent✓
• c.About five percent
• d.About eight percent

Accessible routes limit cross slope to roughly two percent so a wheelchair does not pull to one side. Five percent is the ceiling for running slope on a walk before it is treated as a ramp. Eight percent and the one in twelve figure describe maximum ramp running slope, not cross slope.

A path exceeds five percent running slope on a commercial site. How is it then treated?

• a.As a walk, with a coarse broom finish for traction
• b.As a step, requiring risers to be added at regular intervals
• c.As a ramp, with slope, landing, and handrail requirements✓
• d.As a swale, since it will convey water along its length

Once running slope passes about five percent an accessible route is a ramp and picks up limits on slope and rise plus landings and handrails. Adding texture does not change the classification. A path is not a drainage feature by definition, and converting it to steps would remove accessibility rather than provide it.

A decomposed granite path is specified with a stabilizer. What does the stabilizer provide?

• a.A binder that holds fines together and resists erosion✓
• b.A waterproof surface that sheds all rainfall
• c.A herbicide layer that prevents weeds in the path
• d.A colorant that keeps the granite from fading in sun

Stabilizers bind the fines so the compacted surface holds together underfoot and does not wash out in a storm. The path is still permeable rather than waterproof. Color is a property of the granite itself. Weed suppression comes from compaction and edging, not from the binder.

A steep cut slope must be planted and protected through the first winter. Which combination is most effective?

• a.Erosion control blanket with plantings and fiber rolls✓
• b.Sprinkler irrigation applied at a high rate to settle the soil
• c.Broadcast seed and a light straw scatter over the surface
• d.Plastic sheeting anchored at the crest and the toe

A blanket holds the surface while roots develop and fiber rolls break the slope into short runs that keep water from concentrating. Loose straw blows and floats off. Plastic sheeting sheds water to the toe in a concentrated flow and kills the plants beneath. High-rate irrigation on a bare slope causes the erosion it is meant to prevent.

Why are fiber rolls placed along the contour rather than up and down a slope?

• a.To create planting shelves that hold irrigation water
• b.To intercept sheet flow and shorten the distance water travels✓
• c.To mark the elevations the grading crew must hold
• d.To provide anchor points for the erosion blanket above them

Rolls set on contour catch water moving down the face and break a long slope into short segments so flow never gains erosive velocity. Blanket anchoring is done with staples. The rolls are not planting shelves, and grading elevations are marked with stakes and hubs rather than with erosion control products.

A crew is placing fill on a hillside terrace. What practice produces stable fill?

• a.Placing and compacting the fill in lifts on a benched surface✓
• b.Saturating the fill and allowing it to consolidate under its own weight
• c.Placing the fill against the existing slope face without preparation
• d.End dumping the material and letting it settle over the wet season

Fill placed in thin compacted lifts onto a benched, keyed surface bonds to the existing ground and reaches design density. End dumping leaves loose material that settles for years. Fill placed against an unprepared slope face can slide along that plane. Saturation produces settlement and instability rather than compaction.

A catch basin is being set in a lawn area. At what elevation should its grate be placed?

• a.Slightly below the surrounding grade so water flows into it✓
• b.At the same elevation as the outlet pipe invert
• c.An inch above the surrounding turf so mowers clear it
• d.Level with the highest point of the lawn nearby

A basin only collects water that can reach it, so the grate is set slightly low and the surrounding grade is shaped to fall toward it. Setting it high makes it an obstacle that water bypasses. Matching the high point of the lawn does the same. The outlet invert sits well below the grate by design.

A yard drain system backs up during heavy rain although the pipe is clear. What should be checked next?

• a.Whether the outlet is submerged or blocked at its discharge✓
• b.Whether the basins have solid lids rather than open grated lids
• c.Whether the trench was backfilled with native soil
• d.Whether the pipe was laid with too much fall

A gravity system can only discharge if the outlet is open and above the water it drains into, so a buried, silted, or submerged outlet backs the whole system up. Solid lids would show as no collection rather than as backup. Excess fall increases capacity. Backfill material does not restrict flow inside a clear pipe.

A dry well is proposed to handle roof runoff on a lot with heavy clay subsoil. What is the main concern?

• a.Roof water carries too much sediment for a dry well to accept
• b.Dry wells may only be used with landscape runoff, not roof runoff
• c.Clay will not hold the walls of the excavation during construction
• d.Clay infiltrates too slowly for the well to empty between storms✓

A dry well works by infiltration, and clay subsoil may take days to empty a well that must be ready for the next storm, so a percolation test governs the decision. Excavation stability is a construction issue rather than a performance one. Roof water is relatively clean, and roof runoff is a common and accepted source for infiltration devices.

Where should the finish grade of a lawn be set relative to an adjoining concrete walk?

• a.Level with the walk so the mower can ride on the concrete
• b.About two inches above the walk so the turf edge looks full
• c.About four inches below the walk to allow for thatch buildup
• d.About one inch below the walk so water sheds onto the lawn✓

Setting soil about an inch below the concrete lets water run off the walk into the lawn and keeps soil and mulch from washing across the surface. Grade above the walk sends soil onto the concrete and buries the edge. A flush grade scalps under the mower. Four inches low leaves a trip edge and a trench along the walk.

A laser level is set up to grade a large lawn panel. What does the rod reading at each stake give the operator?

• a.The compaction achieved at that point in the subgrade
• b.The elevation of that point relative to the level instrument plane✓
• c.The horizontal distance from the instrument to that stake
• d.The percent slope between that stake and the instrument

The instrument establishes a level plane and the rod reading tells how far the ground lies below it, which converts directly to elevation. Distance is measured with a tape or by stadia. Slope is computed from two elevations and the distance between them. Compaction is measured with a density test, not with a level.

A plan shows a spot elevation of 101.50 at a patio corner and 100.75 at a drain 25 feet away. What is the slope between them?

• a.About 0.75 percent
• b.About 3.0 percent✓
• c.About 1.5 percent
• d.About 2.0 percent

The fall is 0.75 feet over 25 feet, which is 0.03, or 3 percent. The 0.75 figure mistakes the fall in feet for a percentage. The 1.5 figure would come from half the fall or twice the distance. Two percent would require a fall of half a foot over the same run.

A patio is to be built over the root zone of a mature preserved tree. Which approach is most protective?

• a.A paver field with the base compacted to 95 percent
• b.A slab poured directly on the existing soil with no base
• c.A pier-supported deck or a permeable surface set on grade✓
• d.A conventional slab poured on four inches of compacted base rock

Roots are damaged by excavation and by loss of air exchange, so raising the surface on piers or using a permeable system placed with minimal disturbance is the protective choice. A conventional base requires excavation and heavy compaction over the roots. Higher compaction makes it worse. A slab poured on grade still seals the surface completely.

Bender board is installed to separate a lawn from a planting bed. What is its function?

• a.To carry the load of a mower wheel riding along the edge
• b.To hold the edge line and keep bed material and turf separated✓
• c.To stop irrigation water from crossing between the two areas
• d.To provide a level datum for the finish grade of the lawn

Edging holds a clean line and keeps mulch and turf from migrating into one another. It is not a water barrier, since water moves through and under it. It is not designed to carry wheel loads, and grading elevations are set from stakes and instruments rather than from a flexible edging strip.

A mow strip is specified between a lawn and a block wall. What is its practical purpose?

• a.To act as an expansion joint between the lawn and the wall
• b.To provide a drainage channel along the wall footing
• c.To reinforce the base of the wall against soil pressure
• d.To let a mower wheel run beside the wall without hand trimming✓

A mow strip gives the mower a hard surface to run on right up to the wall, which removes the hand trimming that would otherwise be needed on every visit. It is not a structural element. It is not a drainage channel. Expansion joints occur between rigid elements, and a lawn is not rigid.

Site work is sequenced on a full landscape installation. Which order is correct?

• a.Rough grading, then irrigation lines, then hardscape, then planting✓
• b.Irrigation, then rough grading, then planting, then hardscape
• c.Hardscape, then rough grading, then irrigation, then planting
• d.Planting, then irrigation, then hardscape, then rough grading

Grading establishes the shape of the site, buried utilities and irrigation go in before anything is paved over, hardscape follows, and planting comes last so it is not damaged by equipment. Every other sequence either buries work that must be dug up again or installs plants before the heavy work is finished.

A landscape project will disturb more than one acre of soil. What additional stormwater obligation typically applies?

• a.A dedicated landscape water meter for the disturbed area
• b.A geotechnical report certifying the compaction of all fill
• c.Coverage under the state construction stormwater permit✓
• d.A separate encroachment permit from the county road department

Disturbing an acre or more generally brings a project under the statewide construction stormwater permit, which requires a stormwater pollution prevention plan and site controls. Encroachment permits apply to work in the public right of way. A landscape meter is a water efficiency requirement. Compaction reports address structural fill, not stormwater.

Which practice keeps sediment from leaving a landscape construction site during rain?

• a.Watering exposed soil daily so it does not blow off site
• b.Protecting inlets and installing perimeter controls first✓
• c.Stockpiling excavated soil at the low corner of the property
• d.Sweeping the street at the end of each work week

Sediment control works only if inlet protection and perimeter barriers are in place before the storm, not after. Weekly sweeping lets a week of tracked material wash into the drain. Watering controls dust but does nothing about runoff. Stockpiling at the low corner puts loose soil exactly where water will collect and carry it away.

A boulder is being placed as a landscape feature on a slope. What placement practice is correct?

• a.Set it on the surface so its full shape remains visible
• b.Bury roughly a third of it and seat it on firm compacted ground✓
• c.Set it against a block wall so the wall carries part of its weight
• d.Set it on a bed of sand so it can be adjusted later

Burying part of the boulder on firm ground makes it look natural and keeps it from rolling or settling. A boulder resting fully on the surface reads as placed and is unstable on a slope. Sand bedding lets a heavy stone shift. Leaning a boulder against a wall loads the wall in a way it was not designed for.

Sleeves and conduits are installed under a new driveway before paving. Beyond irrigation, what else should be considered at that stage?

• a.Additional base rock so the sleeves are not crushed
• b.A second layer of sleeves at ninety degrees for future flexibility
• c.Concrete encasement of every sleeve for structural support
• d.Spare conduit for lighting and control wiring added later✓

The cheapest time to add capacity is before pavement goes down, so spare conduit for future lighting and control wiring belongs in that trench. Sleeves at proper depth under a compacted base do not need extra rock or concrete encasement, and a redundant perpendicular layer adds cost without serving a known need.

A retaining wall over four feet tall is part of a landscape contract. What is the appropriate step for a C-27 licensee who does not do engineered walls?

• a.Have the owner sign a waiver accepting responsibility for the wall
• b.Build it as drawn and have the inspector approve it after completion
• c.Obtain the engineered design and permit and use a qualified installer✓
• d.Reduce the wall to a series of three-foot walls stacked one above the other

An engineered design and permit are required, and the work must be performed by someone qualified to build to that design. Stacking terraces does not avoid engineering if the upper wall surcharges the lower one. Inspection does not retroactively substitute for design. An owner waiver does not remove code obligations or liability.

During final grading the crew finds the finish grade at the side yard is two inches above the weep screed at the base of the stucco wall. What must be done?

• a.Lower the grade to restore clearance below the screed✓
• b.Install a curb along the wall to hold the soil back
• c.Seal the base of the stucco with an elastomeric coating
• d.Add a gravel band at the wall so water drains through the soil

The weep screed drains the wall assembly and must stay above grade, so soil covering it has to be removed. A coating traps moisture inside the wall. Gravel placed at the same elevation still blocks the screed. A curb holds soil at the same height and leaves the screed buried.

A bed measures 24 feet by 15 feet and will receive 4 inches of mulch. How many cubic yards are needed?

• a.About 4.4 cubic yards✓
• b.About 6.7 cubic yards
• c.About 2.2 cubic yards
• d.About 3.3 cubic yards

The area is 360 square feet and 4 inches is one third of a foot, giving 120 cubic feet, which divided by 27 is about 4.4 cubic yards. The 2.2 figure corresponds to 2 inches of depth. The 3.3 figure corresponds to 3 inches. The 6.7 figure corresponds to 6 inches of depth over the same area.

A crew must import soil for a bed 40 feet long, 10 feet wide, and 9 inches deep. How many cubic yards should be ordered before waste?

• a.About 7.4 cubic yards
• b.About 10.5 cubic yards
• c.About 9.0 cubic yards
• d.About 11.1 cubic yards✓

Four hundred square feet at 0.75 feet deep is 300 cubic feet, and 300 divided by 27 is about 11.1 cubic yards. The 7.4 figure matches a 6-inch depth. The 9.0 figure does not follow from these dimensions. The 10.5 figure would require a slightly smaller area or a shallower depth.

Which expression converts an area in square feet and a depth in inches directly to cubic yards?

• a.Area times depth in inches, divided by 324✓
• b.Area divided by depth in inches, times 27
• c.Area times depth in inches, times 12, divided by 27
• d.Area times depth in inches, divided by 27

Twelve inches per foot times 27 cubic feet per yard gives 324, so dividing the product of area and depth in inches by 324 yields cubic yards in one step. Dividing by 27 alone forgets the inch to foot conversion. Dividing area by depth is dimensionally wrong. Multiplying by 12 moves the conversion in the wrong direction.

A supplier quotes decomposed granite by the ton at roughly 1.4 tons per cubic yard. How many tons are needed for 9 cubic yards?

• a.About 9.0 tons
• b.About 12.6 tons✓
• c.About 25.2 tons
• d.About 6.4 tons

Nine cubic yards times 1.4 tons per cubic yard is about 12.6 tons. The 6.4 figure comes from dividing rather than multiplying. Nine tons assumes a conversion factor of one, which no aggregate has. The 25.2 figure doubles the correct result and would apply only at 2.8 tons per yard.

A circular lawn has a radius of 12 feet. What is its area?

• a.About 226 square feet
• b.About 452 square feet✓
• c.About 576 square feet
• d.About 75 square feet

Area equals pi times the radius squared, so 3.14 times 144 is about 452 square feet. The 75 figure is the circumference rather than the area. The 226 figure would result from using 12 as the diameter. The 576 figure is the area of a square 24 feet on a side, which encloses the circle.

A triangular corner bed has a base of 18 feet and a height of 12 feet. What is its area?

• a.About 216 square feet
• b.About 60 square feet
• c.About 108 square feet✓
• d.About 30 square feet

The area of a triangle is one half the base times the height, so 18 times 12 divided by 2 is 108 square feet. Thirty square feet is roughly the perimeter dimension summed rather than an area. Sixty square feet does not follow from these numbers. The 216 figure is the full rectangle before it is halved.

A plan is drawn at a scale of one eighth inch equals one foot. A wall measures 5 inches on the plan. How long is it?

• a.20 feet
• b.62.5 feet
• c.10 feet
• d.40 feet✓

At one eighth inch per foot, each inch on the drawing represents 8 feet, so 5 inches is 40 feet. Twenty feet would correspond to two and a half inches. The 62.5-foot figure comes from dividing rather than multiplying. Ten feet would be the answer only if each inch represented two feet.

A bed will be planted with one-gallon shrubs at 30 inches on center in square spacing. Roughly how many plants fit in 400 square feet?

• a.About 40 plants
• b.About 160 plants
• c.About 96 plants
• d.About 64 plants✓

Thirty inches is 2.5 feet, so each plant occupies about 6.25 square feet, and 400 divided by 6.25 is about 64. Forty plants would suit spacing near 3 feet 2 inches. Ninety-six plants implies spacing around 2 feet. One hundred sixty plants implies spacing of about 18 inches.

Sod is sold in rolls covering 10 square feet each, and the lawn measures 32 feet by 45 feet. How many rolls should be ordered including a typical waste allowance?

• a.About 150 rolls
• b.About 144 rolls
• c.About 200 rolls
• d.About 160 rolls✓

The area is 1,440 square feet, which is 144 rolls exactly, and adding roughly ten percent for cuts and curves brings the order to about 160. Ordering 144 leaves nothing for waste. One hundred fifty covers only about four percent waste. Two hundred rolls is nearly forty percent over and would be paid for and discarded.

A seed specification calls for 8 pounds per 1,000 square feet on a 7,500 square foot area. How much seed is required?

• a.About 48 pounds
• b.About 60 pounds✓
• c.About 55 pounds
• d.About 40 pounds

Seventy-five hundred square feet is 7.5 units of 1,000, and 7.5 times 8 pounds is 60 pounds. Forty pounds corresponds to a rate near 5.3 pounds. Forty-eight pounds corresponds to 6.4 pounds. Fifty-five pounds falls short of the specified rate and would leave a thin stand.

A patio slab is 14 feet by 20 feet and 4 inches thick. How much concrete is needed before waste?

• a.About 5.2 cubic yards
• b.About 3.5 cubic yards✓
• c.About 2.6 cubic yards
• d.About 10.4 cubic yards

Two hundred eighty square feet at one third of a foot thick is about 93 cubic feet, or roughly 3.5 cubic yards. The 2.6 figure corresponds to a 3-inch slab. The 5.2 figure corresponds to a 6-inch slab. The 10.4 figure would require a slab a foot thick.

Why do estimators typically add a percentage to a calculated concrete quantity?

• a.Because subgrade irregularity and spillage consume material✓
• b.Because the mix design gains volume when water is added on site
• c.Because concrete shrinks measurably as it cures in the forms
• d.Because suppliers charge a penalty for short loads under five yards

Real subgrades are never perfectly flat, and spillage and slight over-excavation always take more than the theoretical volume, so a waste allowance is standard. Curing shrinkage is negligible in volume terms. Short load fees are a separate line item rather than a reason to buy more material. Adding water does not create usable volume.

An estimator lists crew wages, payroll taxes, and workers' compensation premium for the hours spent on a job. Which cost category is this?

• a.Direct labor cost✓
• b.Contingency
• c.Gross profit
• d.General overhead

Costs tied to hours worked on a specific job, including the burden that rides on wages, are direct labor. General overhead covers costs that exist whether or not that job is running. Contingency is an allowance for unknowns. Gross profit is what remains after direct costs are subtracted from revenue.

Which of these is an overhead cost rather than a direct job cost?

• a.Equipment rental billed for the days used on that job
• b.Plants and irrigation parts delivered to the job site
• c.Subcontracted electrical work performed on that job
• d.Office rent and general liability insurance premiums✓

Overhead is the cost of being in business whether or not any particular job is running, which describes office rent and general insurance. Materials delivered to a job, rental billed for job days, and a subcontract performed on that job all attach to that job and are direct costs.

A job costs $10,000 and the contractor wants a 20 percent gross margin on the selling price. What should the price be?

• a.$11,800
• b.$12,500✓
• c.$13,300
• d.$12,000

A 20 percent margin means cost is 80 percent of price, so price is 10,000 divided by 0.80, or 12,500. Charging 12,000 applies a 20 percent markup on cost, which yields only about a 16.7 percent margin. The 11,800 figure corresponds to neither calculation. The 13,300 figure would represent a 25 percent margin.

What is the difference between markup and margin?

• a.Markup includes overhead and margin includes only profit
• b.Markup is a percentage of cost and margin is a percentage of price✓
• c.Markup is used on time and materials work and margin on fixed price work
• d.Markup applies to labor and margin applies to materials

Markup is added to cost while margin is measured against the selling price, which is why a 20 percent markup produces less than a 20 percent margin. Neither term is tied to a particular cost type, neither excludes overhead by definition, and both apply to any contract structure.

An estimator uses a production rate of 250 square feet of sod installed per crew-hour. How many crew-hours does a 3,000 square foot lawn take?

• a.12 crew-hours✓
• b.8 crew-hours
• c.10 crew-hours
• d.15 crew-hours

Three thousand divided by 250 is 12 crew-hours. Eight hours would imply a rate of 375 square feet per hour. Ten hours would imply 300 square feet per hour. Fifteen hours would imply 200 square feet per hour, and using the wrong rate is how a bid loses money before the crew arrives.

Why does an estimator track historical production rates from completed jobs?

• a.Because a company's own crews and conditions predict its costs✓
• b.Because insurance carriers set premiums based on those rates
• c.Because published rates are required to be used on public work
• d.Because rates determine the markup percentage a company may charge

Actual rates from a company's own completed work capture its crews, equipment, and typical site conditions, which is what makes future bids accurate. Published rates are not mandated on public work. Insurance premiums are based on payroll and classification. Markup is a business decision, not something production rates set.

A bid is prepared as a lump sum for a defined scope. What is the main risk to the contractor?

• a.The contractor cannot be paid until the entire job is complete
• b.The owner may reduce the scope after work has begun
• c.Material price changes are automatically passed to the owner
• d.Underestimated quantities or site conditions come out of the contractor profit✓

In a lump sum contract the contractor carries the estimating risk, so quantities or conditions that come in higher than assumed reduce profit. Scope reductions are handled by change order. Price escalation is not automatically passed through unless the contract says so. Progress payments are normal on lump sum work.

An owner asks for an additional planting bed after the contract is signed. How should the contractor handle it?

• a.Absorb it to protect the relationship and recover it on the next job
• b.Write a change order with the work and price, signed first✓
• c.Add the work and bill it on the final invoice as extra
• d.Add the work and increase the retention held at the end

A written, signed change order fixes the scope and price before the work is done and is the only reliable protection against a dispute at final billing. Adding it silently invites refusal to pay. Absorbing the cost is a gift with no mechanism for recovery. Retention is money the owner holds and is not a way to charge for extras.

A residential landscape job is being sold for $18,000. What does California law require of the agreement?

• a.A written home improvement contract signed before work begins✓
• b.A written contract only if the owner requests one in writing
• c.A written estimate is enough if the owner initials each page
• d.An oral agreement is sufficient if the owner is present at the walkthrough

Home improvement contracts above a low dollar threshold must be in writing and signed before work starts, and an $18,000 landscape job is well past it. An oral agreement does not satisfy the requirement no matter who was present. An estimate is not a contract. The requirement does not depend on the owner asking.B&P Code §7159

On a $30,000 residential landscape contract, what is the limit on the down payment a licensed contractor may collect?

• a.Thirty percent of the contract price
• b.Ten percent of the contract price with no dollar cap
• c.Fifteen percent of the contract price
• d.One thousand dollars or ten percent, whichever is less✓

California caps a home improvement down payment at one thousand dollars or ten percent of the contract price, whichever is the smaller number, so on a thirty thousand dollar job the limit is one thousand dollars. Thirty and fifteen percent are far above any allowed figure, and ten percent without the dollar cap would allow three thousand dollars.

A homeowner signs a landscape contract at their kitchen table on a Monday. What right does California law give them?

• a.A right to cancel until the first payment is deposited by the contractor
• b.No right to cancel, because they initiated the contact with the contractor
• c.A thirty-day right to cancel once work has not yet started
• d.A three-day right to cancel the contract, disclosed in the agreement✓

Home improvement contracts carry a three-day right of cancellation that must be disclosed in the agreement, with a longer period for certain older homeowners. Thirty days is not the statutory period. Cancellation rights are not tied to when a check clears, and a customer-initiated call does not remove the disclosure requirement.

A homeowner asks an unlicensed neighbor to install a small planter for a total of $1,400 including materials. Does the minor work exemption apply?

• a.No, because the total price exceeds the minor work threshold✓
• b.Yes, because materials are excluded from the threshold calculation
• c.Yes, because the work is a single small landscape feature
• d.No, because the exemption applies only to repairs and not to new work

The minor work exemption applies only when the total contract price for labor and materials is under the statutory threshold, and fourteen hundred dollars exceeds it. Being a small feature does not matter. Materials count toward the total rather than being excluded. The exemption is not limited to repair work.B&P Code §7048

A C-27 licensee places an advertisement for landscape services in a local paper. What must the advertisement include?

• a.The name of the qualifying individual on the license
• b.The license number issued by the board✓
• c.The classifications the licensee is qualified to hold
• d.The bond amount currently held by the licensee

California requires a licensee's number to appear in advertising so consumers can verify the license and its status. The bond amount is a matter of public record but is not required in the ad. Listing potential classifications is not required, and the qualifier's name is not part of the advertising requirement.

What is the purpose of the contractor's license bond?

• a.It guarantees the contractor will complete every contract signed
• b.It covers injuries to employees working on licensed projects
• c.It insures the contractor against liability for property damage
• d.It provides limited recovery for certain parties harmed by violations✓

The license bond is a consumer protection device that provides limited recovery to specified claimants when a licensee violates the licensing law, and it is not insurance for the contractor. Property damage liability is covered by general liability insurance. Completion is covered by a performance bond. Employee injuries are covered by workers' compensation.

A C-27 contractor hires three seasonal laborers. What coverage becomes mandatory?

• a.An increased license bond amount filed with the board
• b.A performance bond equal to the value of open contracts
• c.Workers' compensation insurance covering those employees✓
• d.A disability policy naming each employee individually

Any California employer must carry workers' compensation once it has employees, and a licensee must file evidence of it. A performance bond is a contract requirement on particular projects rather than a consequence of hiring. Individual disability policies are not mandated. The license bond amount is set by statute and does not scale with headcount.

A supplier delivering plants to a job wants to protect its right to file a mechanics lien. What step is normally required first?

• a.Recording a notice of completion with the county
• b.Serving a preliminary notice on the owner and lender in time✓
• c.Obtaining the contractor's written consent to lien the property
• d.Filing a copy of the purchase order with the licensing board

A preliminary notice served early in the job is what preserves lien rights for parties without a direct contract with the owner. A notice of completion is recorded by the owner and starts a different clock. The licensing board plays no role in lien rights, and a lien claimant does not need the general contractor's permission.

A landscape plan legend lists a symbol with the notation QUAG 24 box, 7. What does this most likely convey?

• a.A 24-inch root ball depth and a seven-gallon container size
• b.A quantity of 24 plants installed in the seventh planting phase
• c.A species abbreviation, container size, and quantity of that plant✓
• d.A 24-foot spacing for seven plants of that species

Plant schedules commonly pair an abbreviated botanical name with the specified container size and the quantity to be installed, which is what these three entries represent. Reading 24 as the count reverses the fields. Neither the spacing nor the root ball depth is what a box designation and a plant count describe.

Two bidders quote the same landscape job and one is 30 percent lower. What should the owner most reasonably suspect?

• a.The bidders are not pricing the same scope, materials, or quantities✓
• b.The lower bidder has more efficient crews and better buying power
• c.The lower bidder is including a larger contingency in the price
• d.The higher bidder is charging an unlawful markup on materials

A gap that large almost always means the two bids cover different scopes, plant sizes, base depths, or quantities, so the first step is comparing the takeoffs line by line. Efficiency rarely produces a thirty percent difference. There is no unlawful markup limit on private work. A larger contingency would raise a bid rather than lower it.

Which document set is a contractor pricing from when it prepares a quantity takeoff?

• a.The owner's verbal description of the desired result
• b.The specifications alone, since dimensions may change
• c.The plans alone, since specifications describe intent only
• d.The plans and specifications, read together✓

Plans give geometry and location while specifications give materials, installation standards, and quality, and a takeoff needs both. Pricing from plans alone leaves material quality open. Pricing from specifications alone leaves quantities undetermined. A verbal description gives neither and cannot be the basis of a binding price.

A landscape project will require grading, a retaining wall, and a new gate in a public sidewalk area. Which permits should be assumed?

• a.No permits, since the work is entirely landscape improvement
• b.A single building permit covering the entire landscape scope
• c.Only an encroachment permit, since the other work is on private land
• d.Grading and wall permits plus an encroachment permit✓

Different scopes trigger different approvals, so grading and a retaining wall are permitted through the local building or engineering department while work in the public right of way requires an encroachment permit. A single blanket permit is not how jurisdictions handle these. Landscape work is not automatically exempt, and the private-side work still requires its own permits.

A schedule is being built for a landscape installation. Which sequencing constraint most often drives the timeline?

• a.The date the owner selects the final paver color
• b.Inspection holds on grading and underground work before cover✓
• c.The delivery date of the mulch for the planting beds
• d.The availability of a plate compactor from the rental yard

Work that must be inspected before it is covered controls the schedule, because a missed or failed inspection stops everything downstream. Mulch is a late and readily available item. Compactors are widely available. Color selection matters for procurement but rarely holds the critical path the way an inspection hold does.

An estimate includes a contingency line. What is it for?

• a.The markup applied to subcontractor quotations
• b.Profit that will be recognized only if the job finishes early
• c.Cost exposure from conditions that cannot be fully known at bid time✓
• d.The cost of warranty work expected during the first year

A contingency covers risk such as unknown subsurface conditions or minor scope uncertainty that the estimator can anticipate in aggregate but not itemize. Profit is a separate line. Warranty is a distinct reserve. Subcontractor markup is applied directly to those quotes rather than carried as contingency.

A trench 60 feet long, 2 feet wide, and 18 inches deep must be excavated. What volume of soil comes out, before bulking?

• a.About 6.7 cubic yards✓
• b.About 10.0 cubic yards
• c.About 3.3 cubic yards
• d.About 4.4 cubic yards

Sixty by two by one and a half feet is 180 cubic feet, which divided by 27 is about 6.7 cubic yards. The 4.4 figure corresponds to a one-foot depth. The 3.3 figure corresponds to a nine-inch depth. Ten cubic yards would require a trench well over two feet deep at the same length and width.

Why does excavated soil occupy more volume in the truck than it did in the ground?

• a.Because moisture is added during loading and handling
• b.Because the soil bulks up as excavation breaks its compacted structure✓
• c.Because trucks are measured in loose yards and trenches in tons
• d.Because the surveyor measures trench volume to the outside of the stakes

Excavation loosens soil and introduces voids, so bank volume expands into a larger loose volume, which is why haul-off is estimated with a swell factor. Loading does not meaningfully add water. Both trench and truck volumes can be expressed in cubic yards. Stake placement is a layout detail, not a volume effect.

A landscape estimate lists 340 linear feet of edging and 12 hours of equipment time. What are these called on a bid form?

• a.Overhead items, since they support the whole job
• b.Quantities from the takeoff, priced at unit rates✓
• c.Allowances, since the exact figures may change
• d.Contingencies, since they depend on field conditions

Measured quantities multiplied by unit prices are the core of a takeoff-based bid. An allowance is a placeholder dollar amount for undecided scope. A contingency is a reserve for unknowns rather than a measured item. Overhead exists whether or not this job runs and is not measured off the plan.

A landscape maintenance agreement is being priced for a full year. What is the most reliable basis?

• a.The square footage of the property multiplied by a published rate
• b.The price the previous contractor charged, reduced slightly
• c.The hours the crew spent on the last similar property in July
• d.A task-by-task schedule of visits with hours estimated for each season✓

Maintenance labor varies by season and by task, so building the year from a defined visit schedule with seasonal hours produces a price that holds. A single peak month overstates the year. Square footage alone ignores what is actually on the site. Undercutting the prior price prices the competitor's guess rather than the work.

A contractor wants to know whether a completed job made money. Which practice provides that answer?

• a.Comparing revenue for the year to overhead for the year
• b.Counting the days the crew spent against the calendar schedule
• c.Reviewing the deposit history against the contract price
• d.Comparing actual job costs to the estimate line by line✓

Job costing sets actual labor, material, and subcontract costs against the estimated figures and shows exactly where the job gained or lost. Annual revenue against overhead measures the company, not the job. Deposit history tracks cash flow. Days against schedule measures duration without saying what was spent.

A crew plans to trench for irrigation on Thursday morning. When should the regional notification center be contacted?

• a.Only if the property has no as-built utility drawings
• b.At least two working days before excavation begins✓
• c.The morning of the work, once the trench line is staked
• d.Within 24 hours after the excavation is opened

California requires notification at least two working days ahead so owners can mark their facilities before digging starts. Calling the morning of the work leaves no time for marking. Notifying after the trench is open defeats the purpose entirely. The requirement applies regardless of what drawings the property owner happens to have.Gov Code §4216 (DigAlert)

Utility marks are painted across a yard and the crew must trench across one of them. How should the excavation proceed at the marked line?

• a.Cross with the backhoe bucket teeth removed to avoid damage
• b.Offset the trench two feet and cross at right angles by machine
• c.Use the trencher slowly across the mark and watch for the facility
• d.Hand expose the facility within the tolerance zone before machine work✓

Within the tolerance zone on each side of a mark the facility must be exposed by hand or other non-destructive means before powered equipment is used. Slowing a trencher does not prevent a strike. Offsetting two feet does not clear the zone. Removing bucket teeth still leaves enough force to break a line.Gov Code §4216 (DigAlert)

A yellow mark is painted across the proposed trench line. What does that color indicate?

• a.Communication and telecom lines
• b.Potable water lines
• c.Reclaimed water and irrigation lines
• d.Gas, oil, or other flammable material✓

Yellow is the uniform color code for gas, oil, steam, and other flammable or hazardous material, which is why it demands the greatest caution. Potable water is blue, communications are orange, and reclaimed water and irrigation lines are purple, so mistaking a yellow mark for any of those could put a crew on top of a gas line.

A trencher nicks a plastic gas service and gas begins escaping. What is the correct immediate response?

• a.Backfill the trench to smother the escaping gas, then call the utility
• b.Pinch or wrap the line to slow the leak, then call the utility
• c.Evacuate upwind, keep ignition sources away, and call 911✓
• d.Shut down equipment, stay at the trench, and wait for the utility

A damaged gas line is an immediate life hazard, so the crew leaves the area upwind, keeps all ignition sources away, and notifies emergency services and the operator. Attempting a field repair puts a worker directly in the release. Remaining at the trench keeps people in the hazard zone. Backfilling can drive gas into nearby structures.

A worker will enter a trench that is 6 feet deep in Type C soil. What protection is required?

• a.Two workers present so one can assist if a collapse occurs
• b.Sloping, shoring, or a trench shield designed for the soil type✓
• c.Spoil placed on both sides of the trench to balance the load
• d.A ladder within 25 feet of the worker at all times

Once a trench reaches the regulated depth, a protective system suited to the soil type is required, and Type C soil cannot be benched. A ladder is a required means of egress but does not prevent collapse. A second worker on site is not a protective system. Spoil placed at the edge adds load and increases the risk of failure.Cal/OSHA Title 8

Excavated soil is being stockpiled beside an open trench. Where must the spoil pile be placed?

• a.At least two feet back from the edge of the excavation✓
• b.Within one foot of the edge to minimize double handling
• c.Only on the downhill side of the trench regardless of distance
• d.Directly at the trench edge so it can be pushed back quickly

Keeping spoil at least two feet back reduces the surcharge load on the trench wall and keeps material from rolling in on a worker. Piling at the edge or a foot away loads the wall exactly where it is weakest. Placing it downhill does not address the surcharge and may block escape.Cal/OSHA Title 8

A crew is working in a trench 90 feet long that meets the depth requiring a means of egress. How should ladders be arranged?

• a.Ladders spaced so no worker travels more than 25 feet to one✓
• b.One ladder placed at the midpoint of the trench, near the crew
• c.One ladder at each end of the excavation
• d.One ladder for every worker in the trench

The rule limits how far a worker must move sideways to reach a way out, so ladders are spaced to keep that travel within 25 feet. A single midpoint ladder can leave a worker more than 25 feet away. Ladders only at the ends are worse. Egress is measured by distance, not by counting one ladder per person.Cal/OSHA Title 8

What is a competent person required to do on a trenching job?

• a.Remain outside the trench and observe the crew at all times
• b.Hold a state excavation certificate issued after a written examination
• c.Sign the daily time sheets confirming the crew received a safety briefing
• d.Inspect the excavation and protective systems and stop work✓

A competent person is defined by the ability to recognize hazards and by the authority to correct them, which is exercised through inspections and the power to stop work. No state excavation certificate creates the role. Staying out of the trench is not part of the definition. Signing time sheets is a paperwork task with no bearing on hazard control.Cal/OSHA Title 8

When must a trench be re-inspected by the competent person?

• a.Daily before each shift and again after rain or any change in conditions✓
• b.At the completion of the excavation and before backfilling
• c.Once per week and after any change in the protective system
• d.Only when the trench exceeds the regulated depth

Soil conditions change quickly, so inspections occur before each shift and again after rainfall, vibration, or anything else that could affect stability. Weekly inspection leaves days of unmonitored risk. Depth determines whether protection is required, not how often inspection occurs. An inspection at backfill comes far too late to protect anyone.Cal/OSHA Title 8

California's heat illness standard requires shade to be present and available when the temperature reaches what point?

• a.When the temperature exceeds 90 degrees Fahrenheit
• b.When the temperature exceeds 80 degrees Fahrenheit✓
• c.When the temperature exceeds 95 degrees Fahrenheit
• d.When workers request it, at any temperature

Shade must be up and accessible once the temperature passes 80 degrees, and it must be provided on request below that. Ninety-five degrees is the threshold where additional high-heat procedures apply rather than where shade begins. Ninety degrees is not a threshold in the standard, and request-only shade applies only in the cooler range.Cal/OSHA Title 8

How much drinking water must an employer make available to each outdoor worker under the heat illness standard?

• a.At least one quart per worker per hour, kept cool and close✓
• b.A gallon at the start of the shift, refilled at lunch
• c.Two quarts for the shift, provided in sealed containers
• d.Access to a water source within a quarter mile of the work area

The standard is built around one quart per hour per worker, with water kept suitably cool and as close as practicable to where the crew is working. A single gallon at shift start does not stay cool or accessible. A quarter-mile walk is not close by. Two quarts for an entire shift falls far short of the required supply.Cal/OSHA Title 8

What does the acclimatization requirement address for a new landscape laborer starting in July?

• a.A limit of four hours per day for the first two weeks
• b.Close observation during the first days of work in high heat✓
• c.A reduced pay rate during the training period
• d.A medical examination before the worker may work outdoors

Workers who are not used to heat are at the greatest risk in their first days, so the standard requires closer observation during that period. A pre-employment medical exam is not required by the heat standard. Pay is not a safety matter. There is no blanket four-hour daily cap for new workers in the standard.Cal/OSHA Title 8

A worker on a hot day is confused, has stopped sweating, and has hot dry skin. What is the correct action?

• a.Give an electrolyte drink and monitor the worker for the next hour
• b.Move the worker to shade, give fluids, and resume work after a break
• c.Call 911 immediately and begin active cooling while help is on the way✓
• d.Have the worker rest in the truck with the air conditioning running

Confusion with hot dry skin points to heat stroke, a medical emergency in which delay costs lives, so emergency services are called and aggressive cooling begins at once. Resuming work is dangerous. Sitting in a truck delays both cooling and treatment. Fluids and observation are appropriate for heat exhaustion but not for these signs.

What written program does Cal/OSHA require every California employer to have in place?

• a.A respiratory protection program covering all field employees
• b.A confined space entry program for irrigation vaults
• c.An injury and illness prevention program with training✓
• d.A hazardous materials business plan filed with the county

Every California employer must maintain an injury and illness prevention program covering responsibility, hazard identification, correction, training, and communication. A hazardous materials business plan applies only above reporting quantities. A respiratory program is required only where respirators are used. A confined space program applies only where such spaces exist.Cal/OSHA Title 8

A landscape worker suffers an amputation on a chipper and is hospitalized. What is the employer's reporting obligation?

• a.Report it to the insurance carrier, which notifies the state
• b.Report it only if the worker misses more than three days of work
• c.Report it to Cal/OSHA immediately, within the required short window✓
• d.Enter it in the injury log and report it at the next quarterly filing

A serious injury such as an amputation or hospitalization must be reported to Cal/OSHA immediately, within a short statutory window, in addition to any log entry. Quarterly filing is far too slow. The carrier's notification does not satisfy the employer's duty. The reporting trigger is the seriousness of the injury rather than days away from work.

A Safety Data Sheet accompanies a landscape chemical. What must the employer do with it?

• a.Keep it accessible to employees and train them on the hazards✓
• b.Attach a copy to each container before the product is used
• c.Retain it in the office and produce it only if an inspector asks
• d.File it with the county agricultural commissioner within 30 days

Hazard communication requires that data sheets be readily accessible to workers on every shift and that employees be trained on what they contain. Filing with the county is not the general requirement. Sheets are not attached to containers, which carry labels instead. Locking them in an office defeats the purpose of accessibility.

A pesticide label carries the signal word DANGER. What does that indicate?

• a.The product must be applied by two workers working together
• b.The product is restricted to agricultural use only
• c.The product may only be applied between dusk and dawn
• d.The product is the most acutely hazardous signal word class✓

Signal words rank acute hazard, with DANGER the most severe, followed by WARNING and then CAUTION. The signal word does not by itself make a product restricted use, does not dictate crew size, and does not set application hours. Those requirements come from other parts of the label and from state regulation.

A crew wants to apply a pesticide at twice the label rate to get faster results on a heavy weed stand. What is the correct position?

• a.Acceptable if the applicator is licensed and the site is fenced
• b.Prohibited, because the label directions carry the force of law✓
• c.Acceptable if the property owner provides written consent
• d.Acceptable if the label lists no maximum concentration

Applying a pesticide inconsistently with its labeling is a violation, so exceeding the labeled rate is unlawful regardless of who applies it or who consents. A license authorizes an applicator to use a product as labeled, not beyond it. Absence of a stated maximum does not permit doubling. Owner consent cannot waive a legal requirement.

What does the restricted entry interval on a pesticide label establish?

• a.How long the applicator must wear a respirator after spraying
• b.How long the container may be stored before disposal
• c.How long the product remains effective after mixing
• d.How long people must stay out of the treated area after application✓

The restricted entry interval is the waiting period before anyone may enter the treated area without the specified protective equipment. Product stability after mixing and container storage life are separate label items. Respirator use is governed by the personal protective equipment section rather than by the entry interval.

A landscape company wants to apply pesticides for hire in California. What is generally required of the business itself?

• a.A permit from the local water district for each application site
• b.A single certificate held by the company owner and no other filing
• c.Registration as a pest control business with the state and county✓
• d.A contractor license classification specific to chemical application

Applying pesticides for hire requires the business to be licensed and registered with the state regulator and with the counties where it works, in addition to certified individuals directing the work. One personal certificate does not license the business. There is no separate contractor classification for chemical application, and water districts do not permit routine applications.

An empty pesticide container is being prepared for disposal. What is the correct handling?

• a.Puncture it and place it in the job site dumpster
• b.Rinse it with clean water at the shop and pour the rinsate into a floor drain
• c.Store it sealed until the next application uses the same product
• d.Triple rinse it, add the rinsate to the spray tank, then dispose as directed✓

Triple rinsing recovers residue into the tank where it is used as intended, and the container is then disposed of according to the label and local rules. Putting an unrinsed container in a dumpster disposes of pesticide residue improperly. Rinsate poured into a drain enters the sewer. Refilling a container that was emptied is not a disposal method.

Wind is gusting to 15 miles per hour and a herbicide application is scheduled next to a vegetable garden. What is the appropriate decision?

• a.Postpone the application until conditions reduce drift risk✓
• b.Apply while shielding the garden with a tarp held by a worker
• c.Apply at a lower pressure and increase the walking speed
• d.Apply with a finer nozzle so less material is used overall

Drift onto a non-target site is a violation and a real hazard, and the reliable control is to wait for suitable conditions. Finer droplets drift more, not less. A hand-held tarp puts a worker in the spray zone and does not stop airborne drift. Faster walking at lower pressure reduces rate without controlling where the spray goes.

What personal protective equipment is required when mixing and loading a pesticide concentrate?

• a.Whatever the applicator judges appropriate for the product
• b.A respirator whenever the product carries a signal word
• c.The equipment specified on that product's label for mixing✓
• d.Gloves and eye protection for any liquid product

The label states the required protective equipment, and the mixing and loading step often requires more than application because the concentrate is being handled. Applicator judgment does not override the label. A single default of gloves and eye protection may be insufficient. Respirator requirements come from the label rather than from the signal word alone.

A chainsaw operator is limbing a fallen tree. Which practice reduces kickback risk?

• a.Cutting with the tip of the bar to keep the body away from the wood
• b.Keeping the upper tip of the guide bar clear of contact with material✓
• c.Running the chain slightly loose so it releases if it binds
• d.Removing the chain brake so the saw does not stall in the cut

Kickback occurs when the upper quadrant of the bar nose contacts material, so keeping that zone clear is the primary control. Disabling the chain brake removes the device that stops the chain during a kickback. Deliberately cutting with the tip is the classic way to cause one. A loose chain can derail and increases risk rather than reducing it.

Which combination of protective equipment is appropriate for ground-level chainsaw work?

• a.Hearing protection, a dust mask, and high-visibility clothing
• b.A hard hat with a face shield and standard work clothing
• c.Safety glasses, gloves, and steel-toe boots
• d.Head, eye, and hearing protection plus chaps and boots✓

Chainsaw work needs the head, eyes and face, hearing, and legs protected together, since chaps address the most common severe injury. Glasses and boots alone leave the legs and hearing unprotected. A hard hat over ordinary clothing leaves the legs exposed. A dust mask and vest address neither noise-level injury risk nor contact with the chain.

How should a chainsaw be started when no bench or stable surface is available?

• a.By placing it on the ground or gripping it between the legs✓
• b.By bracing the bar against a log and pulling the starter cord
• c.By resting it on a tailgate and pulling the cord with the throttle locked open
• d.By drop starting, holding the saw away from the body

A saw is started on the ground or with the rear handle clamped between the knees, with the chain brake engaged, so the moving chain is controlled. Drop starting swings a running saw through the air. Bracing the bar against a log puts the chain against material at startup. Locking the throttle open makes the chain run immediately at speed.

A crew member notices tree limbs within 10 feet of an energized overhead distribution line. What is the correct action?

• a.Trim only after shutting off power at the building main panel
• b.Stop and arrange for qualified line clearance tree trimmers✓
• c.Trim with insulated gloves rated for the line voltage
• d.Trim with a fiberglass pole saw while standing on dry ground

Work near energized lines within the minimum approach distance is restricted to qualified line clearance personnel and must be coordinated with the utility. A fiberglass pole does not make an untrained worker qualified. Rubber gloves are not adequate for distribution voltages. A building panel does not de-energize a utility distribution line.

An aluminum extension ladder is being carried across a yard toward a hedge near overhead service conductors. What is the primary hazard?

• a.Loss of the ladder's load rating from carrying it extended
• b.Contact between the conductive ladder and the energized conductors✓
• c.Damage to the hedge from the ladder feet during setup
• d.Bending of the ladder rails while it is carried horizontally

An aluminum ladder conducts, and raising or carrying it near overhead conductors is a leading cause of electrocution in outdoor trades. Rail bending is a maintenance concern rather than a life hazard. Damage to plant material is a quality issue. Carrying a ladder does not alter its rated capacity.

A straight ladder is set to reach a 16-foot height. Where should the base be placed?

• a.About eight feet from the wall so the angle is comfortable
• b.About four feet from the wall, following the four to one rule✓
• c.Directly against the wall with the ladder tied at the top
• d.About two feet from the wall for maximum stability

The four to one rule places the base one foot out for every four feet of working height, so a 16-foot height calls for about four feet. Two feet makes the ladder too steep and prone to tipping backward. Eight feet makes it too shallow and likely to slide out. A ladder set vertically against a wall is unstable even if tied.

A worker is clearing a jam in a chipper infeed. What must be done first?

• a.Shut down the engine, wait for motion to stop, and lock out✓
• b.Have a second worker stand by the control bar while the jam is cleared
• c.Reverse the feed rollers and pull the material out by hand
• d.Raise engine speed briefly to push the jammed material through

Powered equipment must be shut down, allowed to come to a complete stop, and secured against restart before anyone reaches into it. Reversing rollers still leaves a running machine. A second worker at the controls is not a substitute for de-energizing. Increasing engine speed puts more energy into the machine while a hand is near the infeed.

What is the safest way to feed brush into a chipper?

• a.Feed butt end first, release it, and step to the side✓
• b.Feed several small pieces at once so the rollers grip quickly
• c.Push the last portion in with a foot to keep hands clear
• d.Stand directly in front of the chute to guide material straight in

Feeding butt first, letting go, and standing to the side keeps the worker out of the path of both the material and any kickback. Using a foot puts a limb near the rollers. Handfuls of small material encourage reaching in. Standing directly in front of the chute is the position most exposed to material thrown back.

A compact tractor with a rollover protective structure is used on a sloped property. What must the operator do for the structure to work?

• a.Add wheel weights matched to the slope of the property
• b.Fold the structure down when working under low branches
• c.Operate only in the lowest gear range available
• d.Wear the seat belt so the operator stays within the protected zone✓

A rollover structure protects the operator only if the seat belt keeps them in the seat during a rollover, which is why the two are treated as one system. Folding the structure removes the protection. Wheel weights improve traction but do not substitute for restraint. Gear selection matters for control but not for the protective structure.

How should a walk-behind mower be operated on a slope, and how does that differ from a riding mower?

• a.A walk-behind mows across the slope while a rider goes up and down✓
• b.A walk-behind mows up and down while a rider goes across the slope
• c.Both are operated across the slope to keep the deck level
• d.Both are operated up and down the slope for maximum traction

A walk-behind is mowed across the face so the operator is not in line with a machine that could roll back, while a rider is driven up and down because it is more likely to tip sideways. Applying one rule to both machines misses that the hazards are different, and reversing them puts the operator in the path of the specific failure each machine has.

A string trimmer is being used along a driveway where cars are parked. What control best reduces the risk of thrown objects?

• a.Removing the debris shield so cut material falls straight down
• b.Keep the guard on, wear eye protection, and aim discharge away✓
• c.Trimming toward the vehicles so debris is caught by the tires
• d.Reducing engine speed and moving more quickly along the edge

The guard, eye protection, and controlling the direction of discharge together address both the operator and the property. Slower engine speed still throws material and reducing time near the hazard does not remove it. Removing the guard eliminates the primary control. Directing debris toward vehicles guarantees the damage the question is about.

A gas can is being used to refuel a hot backpack blower at the end of a run. What is the correct practice?

• a.Shut down the engine, let it cool, and refuel away from ignition✓
• b.Refuel with the engine running but the throttle at minimum
• c.Refuel quickly while the engine idles so the fuel line stays primed
• d.Refuel on the truck bed so spills fall away from the work area

Gasoline vapor ignites readily on hot surfaces, so the engine is shut off, allowed to cool, and refueled on stable ground away from ignition sources. Refueling a running engine at any throttle setting is a fire risk. A truck bed lined with plastic can build static and is a poor refueling surface.

At what sound level does an employer generally need to implement hearing conservation measures for landscape crews?

• a.Only when equipment lacks a factory muffler
• b.An eight-hour average of about 65 decibels
• c.An eight-hour average of about 85 decibels✓
• d.Any level at which conversation is possible at three feet

Hearing conservation is triggered near an eight-hour average of 85 decibels, which mowers, blowers, and chainsaws routinely exceed. Sixty-five decibels is closer to normal conversation. A conversation test is a rough field indicator rather than the regulatory trigger. Muffler condition affects the level but does not define the requirement.

A crew is wet-cutting concrete pavers with a masonry saw. What hazard is that method controlling?

• a.Respirable crystalline silica dust generated by cutting✓
• b.Static charge accumulating on the saw housing
• c.Blade fracture caused by heat buildup in the cut
• d.Noise transmitted through the blade to the operator

Cutting concrete releases respirable crystalline silica, and water at the blade is the primary engineering control that keeps it out of the air. Cooling does extend blade life but is not the regulated hazard. Water does not reduce noise, which still requires hearing protection. Static is not a meaningful hazard on a masonry saw.

Extension cords are being run to power tools on a landscape job. What is required for the temporary electrical setup?

• a.Ground fault protection at the receptacle or on the cord✓
• b.Cords may be spliced with tape if the conductors are fully covered
• c.Cords may be run through a doorway if the door is padded at the edge
• d.Cords rated for indoor use may be used if they are kept off wet ground

Temporary power on construction and outdoor work requires ground fault protection, since damp conditions and damaged cords are the usual electrocution path. Indoor-rated cords are not suitable outdoors. Taped splices are not permitted repairs. Running cords through doors and windows creates exactly the damage the protection is meant to catch.

A skid steer is being loaded onto a trailer using ramps. Which practice is correct?

• a.Load heavy end uphill, on level ground, with the trailer secured✓
• b.Load with the heavy end downhill so the machine settles onto the deck
• c.Load with a spotter standing on the ramp to guide the operator
• d.Load quickly to reduce the time the machine is on the ramps

Keeping the heavy end uphill maintains stability on the incline, and level ground with the trailer hitched and secured keeps it from shifting. Loading heavy end down invites a tip. A spotter on the ramp is standing in the crush zone. Speed increases rather than reduces the chance of a loss of control.

Equipment is being backed out of a driveway across a public sidewalk. What is the appropriate control?

• a.Backing slowly with the window down to listen for pedestrians
• b.Sounding the horn twice before starting to back up
• c.A trained spotter in view of the operator plus a backup alarm✓
• d.A mirror added to the machine to eliminate the blind spot

Backing incidents happen in blind areas, so a spotter positioned where the operator can see them, combined with a working alarm, addresses both the machine and the pedestrians. A mirror reduces but does not eliminate blind areas. Listening is not a reliable substitute for seeing. A horn warns without confirming the path is clear.

A crew works from a truck parked on a residential street with equipment staged behind it. What traffic control is appropriate?

• a.High-visibility apparel plus cones or signs delineating the work area✓
• b.Working only during daylight, which removes the need for delineation
• c.A single cone at the rear bumper to mark the vehicle
• d.Parking with hazard lights on, which is sufficient on a residential street

Drivers need advance warning of the work area, and workers need to be conspicuous, so both delineation and high-visibility apparel apply. Hazard lights alone do not define a work zone. One cone marks the truck rather than the area where people are working. Daylight improves visibility but does not create a marked work zone.

Two workers must move a 300-pound boulder from a truck to a bed 40 feet away. What is the correct approach?

• a.Slide it down a plank and walk it with pry bars
• b.Use mechanical equipment or rigging rated for the load✓
• c.Lift together using a two-person carry with straps
• d.Roll it end over end across a sheet of plywood

A load of that weight belongs on a machine or in rigging rated for it, because manual handling exposes workers to crushing injuries that no lifting technique prevents. A two-person carry is far over safe manual limits. Rolling and prying keep hands and feet in the path of the load throughout the move.

What lifting technique reduces back injury when handling bagged soil amendments?

• a.Bend at the waist and lift with a smooth continuous motion
• b.Twist toward the destination while the load is rising
• c.Keep the load close, lift with the legs, and turn the feet✓
• d.Hold the bag at arm's length to keep it away from clothing

Keeping the load close, using leg muscles, and pivoting with the feet keeps the spine aligned and reduces both compression and twisting. Bending at the waist loads the lower back directly. Twisting while lifting is the motion most associated with disc injury. Holding a load at arm's length multiplies the force on the spine.

A worker will be pruning from an elevated work platform 12 feet above grade. What is required?

• a.A ground worker holding the platform base while it is elevated
• b.A guardrail on three sides with the fourth open for tool access
• c.A hard hat and safety glasses, which are sufficient at that height
• d.A body harness with a lanyard attached to the platform anchor✓

Occupants of an elevated work platform are tied off to the anchor provided on the platform, so a fall or a sudden movement cannot eject them. Leaving one side open removes the protection guardrails provide. A worker at the base cannot arrest a fall. Head and eye protection are required but do not address falls.

A tree crew climber is working aloft on rope. What is the essential fall protection principle?

• a.The climber remains tied in on a properly rigged system at all times aloft✓
• b.The climbing line alone is sufficient once the climber is above the first crotch
• c.A ground worker tending the rope substitutes for a second attachment
• d.Spurs provide the primary attachment while pruning a live tree

A climber stays tied in on a correctly rigged climbing system for the entire time aloft, including while repositioning. Height above the first crotch changes nothing. Spurs are for removals rather than pruning live trees and are not fall protection. A ground worker cannot replace the climber's own attachment.

A crew must work in a landscape area with visible poison oak. What is the appropriate precaution?

• a.Burn the cut material on site so the oil is destroyed
• b.Rely on prior exposure, since sensitivity decreases with repeated contact
• c.Apply a barrier cream and work in short sleeves for ventilation
• d.Cover the skin, use disposable gloves, and wash afterward✓

The plant oil transfers from clothing, tools, and skin long after contact, so covering up, using disposable gloves, and washing everything afterward is the practical control. Burning the material puts the oil into smoke that can be inhaled with severe consequences. Short sleeves expose skin. Sensitivity commonly increases with repeated exposure rather than decreasing.

A worker is stung by wasps disturbed while trimming a hedge and begins wheezing with swelling of the face. What is the correct response?

• a.Apply ice and let the worker rest in the shade for 30 minutes
• b.Call 911 immediately, since these signs suggest a severe allergic reaction✓
• c.Give an over-the-counter antihistamine and continue observing
• d.Move the worker to the truck and drive to a clinic when the crew finishes

Wheezing and facial swelling indicate a systemic allergic reaction that can progress to airway closure within minutes, so emergency services are called at once. Ice and rest treat a local reaction only. An oral antihistamine acts too slowly. Waiting for the crew to finish delays care during the most dangerous window.

What is the practical purpose of a tailgate safety meeting before a landscape crew starts work?

• a.To document that the crew arrived on site at the scheduled time
• b.To assign production targets for the day to each crew member
• c.To satisfy the recordkeeping requirement of the workers' compensation carrier
• d.To review the specific hazards of that site and the controls for them✓

A tailgate meeting connects the day's actual hazards, such as a trench, a slope, or overhead lines, to the controls the crew will use. Insurance recordkeeping is a byproduct rather than the purpose. Production assignments are a scheduling matter. Arrival documentation is a payroll function.

A hand-dug pothole exposes a fiber optic conduit that was not marked. What should the crew do?

• a.Move the conduit aside carefully and continue machine excavation
• b.Continue trenching but hand dig within a foot of the conduit
• c.Stop work there and notify the center and the operator✓
• d.Backfill over the conduit and proceed on the opposite side of the yard

An unmarked facility means the marking was incomplete, so work stops in that area and the center and operator are notified before excavation resumes. Continuing to trench nearby risks a strike on a line whose route is unknown. Moving a facility is never the excavator's to do. Covering it and moving elsewhere leaves the hazard for the next pass.

An irrigation valve vault is deep, has limited access, and has been closed for months. What should the crew consider before entry?

• a.Whether the vault is a confined space requiring testing✓
• b.Whether a ladder can reach the bottom of the vault
• c.Whether the valve can be reached with an extension tool
• d.Whether the vault lid is heavy enough to require two workers to lift

A vault with limited entry that is not designed for continuous occupancy can be a confined space where oxygen deficiency or accumulated gas is possible, so atmospheric testing and a written program come first. Ladder reach, tool reach, and lid weight are practical details that do not address the atmosphere inside.

A landscape crew works around a residential swimming pool during an installation. What safety issue should be addressed in planning?

• a.Whether the pool chemistry will damage nearby plantings
• b.Whether the pool surface can support staged materials
• c.Whether barriers and access control the drowning hazard✓
• d.Whether pool equipment noise requires hearing protection

An open pool near a work area is a drowning hazard, and keeping barriers functional and access controlled is the planning issue. Water chemistry affects plants rather than worker safety. Equipment noise at a residential pool is well below the hearing conservation threshold. Staging materials on a pool cover is not a legitimate option to evaluate.

A crew member reports a near miss when a rock was thrown from a mower toward a bystander. How should this be handled?

• a.Investigate it and correct the cause before it repeats✓
• b.Note it informally, since no one was injured and no report is required
• c.Discipline the operator so the behavior is not repeated
• d.Record it in the injury log as a first aid case

Near misses reveal the same failures that produce injuries, so the value is in investigating and correcting the cause, whether that is a missing discharge chute, debris on the lawn, or the mowing direction. Treating it informally discards the warning. Discipline addresses the person rather than the condition. Injury logs record injuries, not near misses.

A worker will use a respirator for a dusty demolition task. What must happen before the respirator is worn?

• a.The worker signs a form acknowledging the dust hazard
• b.The employer supplies a disposable respirator of any rating
• c.The worker is trained by the equipment supplier at the point of sale
• d.Medical evaluation, fit testing, and training under a written program✓

Required respirator use triggers a written program with medical evaluation, fit testing, and training, because a poorly fitted respirator gives a false sense of protection. A signed acknowledgment does not establish that the worker can safely wear one. Any disposable model is not equivalent, and supplier instruction does not replace the program.

A grinding wheel guard on a shop tool interferes with a cut and a worker suggests removing it. What is the correct response?

• a.Remove it and mark the tool as modified for that purpose
• b.Keep the guard in place and use a tool suited to the cut✓
• c.Remove it and require a face shield in place of the guard
• d.Remove it for the cut and reinstall it immediately afterward

Machine guards are the primary control and stay in place, so the answer is to select a tool that performs the cut with the guard installed. Temporary removal exposes the worker during exactly the moment of highest risk. Marking a tool as modified does not restore protection. A face shield is added protection rather than a substitute for a guard.

What is the main purpose of lockout and tagout procedures on landscape equipment?

• a.To document which employee last serviced each machine
• b.To prevent theft of equipment left overnight on a job site
• c.To keep equipment from starting or releasing energy during service✓
• d.To keep unauthorized workers from operating company machines

Lockout and tagout control hazardous energy so a machine cannot start or release stored energy while someone is working on it. Restricting who may operate equipment is a training and authorization matter. Service records are maintenance documentation. Overnight security is unrelated to energy control.

A hose is stretched across a walkway that clients use to reach the front door. What should the crew do?

• a.Set a cone at each end of the hose and leave it in place
• b.Flatten the hose against the pavement with weights
• c.Reroute it or ramp over it so the walkway stays clear✓
• d.Post a warning sign at the entry to the walkway

The trip hazard is the hose lying in the path, so removing it from the path or ramping over it addresses the cause. Cones mark a hazard without removing it. Weights hold the hose down but leave the same obstruction. Signage relies on people reading and reacting rather than eliminating the condition.

A landscape crew loads brush into a dump trailer for hauling. What securement is required on public roads?

• a.The load must be covered and secured so material cannot escape✓
• b.Securement applies only on freeways and not on local streets
• c.Only loads over one ton require covering on public roads
• d.Loose loading is acceptable if the sides of the trailer are high

A load that can blow or fall out must be covered and secured regardless of trailer height, weight, or which road is being used. Tall sides do not stop light debris from lifting out. Weight thresholds do not exempt a load from spilling. Local streets carry the same obligation as highways.

A worker cuts a hand on a shovel blade and the wound needs cleaning and a bandage. What should the employer do?

• a.Provide first aid from a stocked kit and review the cause✓
• b.Take no action unless the worker requests medical treatment
• c.Send the worker home for the day and record it as lost time
• d.Record the injury and wait to see whether it becomes infected

A stocked first aid kit and prompt care are required, and looking at how the injury happened is what prevents the next one. Waiting for the worker to ask fails the duty to provide care. Sending the worker home is neither necessary nor an accurate lost time classification. Waiting for infection delays both treatment and correction.

A crew works alone on a large rural property with no cell coverage in part of the site. What planning step matters most?

• a.Scheduling work only during business hours at the property
• b.Issuing each worker a whistle for signaling across the property
• c.Establishing an emergency communication and response plan for the site✓
• d.Limiting work to areas within sight of the access road

Emergency response depends on being able to summon help and direct it to a location, so a site-specific plan covering communication, meeting points, and addresses is the controlling step. A whistle helps within earshot only. Restricting work areas limits the job rather than solving the problem. Business hours do not restore coverage.

A landscape company reviews its injury records and finds most claims involve strains from handling materials. What is the most effective response?

• a.Post reminders about proper lifting technique in the shop
• b.Require back belts for all field employees on every job
• c.Increase the deductible on the workers' compensation policy
• d.Change how materials are handled, using equipment and carts✓

Engineering the hazard out, by using carts, machines, and smaller unit loads, is more effective than depending on workers to lift correctly under production pressure. Posters do not change the load. Back belts have not been shown to prevent injury and can create false confidence. Changing the deductible affects cost rather than injuries.