California CSLB C-42 Sanitation System Examination

What is the primary factor for calculating septic tank capacity for a single-family home?

• ANumber of bedrooms.
• BSquare footage of the home.
• CLot acreage or parcel size.
• DBathroom count.

Which of these determines the size of the required leach field area?

• ASoil percolation rate.
• BDistance to property line.
• CRoof drain output.
• DLandscaping type.

Before excavating a new sanitary line, what must a contractor do first?

• AContact DigAlert (811).
• BOrder PVC pipes and fittings.
• CInstall the septic tank.
• DCheck soil moisture content.

What is the minimum required capacity for a residential septic tank serving a 3-bedroom home?

• A1000 gallons.
• B750 gallons.
• C1200 gallons or more.
• D1500 gallons or more.

When planning a seepage pit, what geological feature restricts its depth?

• AHigh groundwater table.
• BTopsoil thickness.
• CSurface vegetation.
• DSurface slope of the land.

Who must approve the plans for a new commercial septic system installation?

• ALocal environmental health agency.
• BThe property owner.
• CThe local water supplier.
• DThe municipal fire marshal's office.

When calculating the required slope for a gravity sewer line, what is standard for a 4-inch pipe?

• A1/4 inch per foot.
• B1/8 inch per foot minimum.
• C1/2 inch per foot.
• D1 inch per foot.

What is a common minimum required cover over a newly installed septic tank?

• A6 to 12 inches.
• B36 inches.
• C48 inches or more.
• DNo cover is required.

Which bed material is most commonly used for laying septic tank piping?

• ASand or fine gravel.
• BLarge boulders or rubble.
• CHeavy clay soil.
• DUntreated wood chips.

During leach field installation, why is filter fabric placed over the gravel?

• ATo stop soil from clogging the gravel.
• BTo keep the pipe warm in winter.
• CTo stop roots completely.
• DTo add structural support to the trench.

How should the inlet baffle of a septic tank be positioned relative to the outlet baffle?

• AThe inlet is higher than the outlet.
• BThe inlet is typically lower than the outlet.
• CThey must be exactly level.
• DThe inlet must touch the bottom.

What is the purpose of installing a cleanout near the building before the septic tank?

• ATo access and clear blockages.
• BTo allow rainwater to enter the system.
• CTo vent sewer gases into the yard.
• DTo sample the effluent quality.

When backfilling a new leach trench, what practice should be avoided?

• ADriving heavy equipment over them.
• BMounding the soil slightly.
• CSeeding the area with grass.
• DHand-tamping the trench edges carefully.

What is used to seal the connections where pipes enter and exit the septic tank?

• AWatertight flexible seals.
• BStandard duct tape.
• CDry sand packing.
• DExpanding foam insulation sealant.

What test is commonly performed on a newly installed sewer lateral before burial?

• AWater test with 10-foot head.
• BSoil compaction test.
• CSmoke test for existing leaks.
• DChlorine residual test for supply.

When repairing a broken section of clay sewer lateral, what is the best connection method?

• AShielded rubber couplings.
• BPouring concrete over the gap.
• CGluing it with PVC cement.
• DWrapping it with roofing tar.

What must be installed if a sewer lateral drops sharply in elevation to meet the main?

• AA drop manhole connection.
• BA standard 90-degree elbow fitting.
• CA smaller diameter pipe.
• DA venting stack.

What is a clear indicator that a septic tank needs pumping?

• AScum and sludge reach 25-33%.
• BThe grass over the tank is very green.
• CThe tank is over 1 year old.
• DThe house is being sold.

How often should an effluent filter in a septic tank typically be cleaned?

• AEvery 6 to 12 months.
• BEvery 10 years.
• COnly when it breaks.
• DNever, they are self-cleaning.

What is the most critical hazard when entering a septic tank for repairs?

• AAsphyxiation from toxic gas.
• BSlipping on wet and slimy surfaces.
• CEncountering rodents or pests.
• DStaining clothing with sewage.

At what trench depth does Cal/OSHA generally require a protective system like shoring?

• A5 feet.
• B2 feet.
• C10 feet.
• D20 feet.

What must be placed around an open excavation at the end of the workday?

• ABarricades or fences.
• BA bright warning light.
• CA tarp over the trench.
• DA hired security guard on site.

Before opening a septic tank lid, a worker should always wear:

• AGloves and eye protection.
• BA respirator.
• CA hazmat suit.
• DSteel-toed boots and a hard hat.

When testing a sewer lateral, what safety precaution is essential if using compressed air?

• ADo not exceed the test pressure.
• BUse pure oxygen to pressurize.
• CStand directly in front of the test plug.
• DHeat the pipe to increase pressure.

How far back from the edge of a trench must excavated soil (spoils) be kept?

• AAt least 2 feet.
• BAt least 6 inches.
• CAt least 1 foot.
• DAt least 5 feet.

What happens if a leach field is undersized for the daily effluent flow?

• AIncreased property value.
• BFailure and surfacing effluent.
• CFaster breakdown of solids.
• DBetter groundwater recharge rates.

Which document is essential for accurately estimating material costs for a new septic install?

• AA recent property tax bill.
• BThe approved engineering plan.
• CThe previous owner's deed.
• DA random guide from the internet.

What is the minimum setback required from a septic tank to a property line?

• A2 feet.
• B5 feet.
• C10 feet.
• D20 feet.

When assessing a site, what indicates poor soil percolation?

• ASandy soil texture.
• BHeavy clay content.
• CAbundant gravel.
• DLoamy topsoil.

Why is a site evaluation necessary before designing an OWTS?

• ATo select exterior paint colors.
• BTo check soil and setbacks.
• CTo plan the interior plumbing layout.
• DTo satisfy the HOA requirements.

Which variable must be considered when estimating labor hours for a trenching job?

• APipe color.
• BSoil hardness and rocks.
• CAir temperature.
• DThe brand of the septic tank.

What is the typical minimum required setback from a leach field to a private water well?

• A50 feet or less.
• B100 feet.
• C25 feet.
• D10 feet.

What must be done to the bottom of a leach trench before adding gravel?

• AIt must be compacted with a heavy plate compactor.
• BIt must be scarified to remove smeared soil.
• CIt must be lined with plastic.
• DIt must be painted with sealer.

When installing a concrete septic tank, how is it typically lowered into the excavation?

• ABy several workers lifting it by hand.
• BUsing a crane or boom truck.
• CSliding it down a wooden ramp.
• DDropping it from a dump truck bed.

What is the purpose of an advanced treatment unit (ATU) in a new installation?

• ATo bypass the septic tank entirely.
• BTo provide secondary treatment.
• CTo pump water directly into the drinking well.
• DTo reduce the size of the house.

How deep should the gravel layer typically be below the distribution pipe in a leach line?

• A2 inches.
• B6 to 12 inches.
• C36 inches or more.
• DNo gravel is used.

Which component ensures effluent is evenly distributed among multiple leach lines on a sloped site?

• AA grease trap.
• BA distribution box.
• CA backflow preventer.
• DAn effluent filter in the tank.

What type of pipe is most commonly used for the perforated distribution lines in a leach field?

• ACast iron sewer pipe.
• BPVC or HDPE pipe.
• CGalvanized steel pipe.
• DCopper tubing.

When installing a fiberglass septic tank, what is a crucial installation step?

• APainting the inside of the tank.
• BFilling it with water.
• CLeaving the lid off permanently.
• DInstalling it entirely above ground.

How should tree roots in a sewer lateral ideally be handled permanently?

• AFlush them with hot water.
• BReplace or line the pipe.
• CPour bleach down the toilet.
• DIgnore them if water still flows.

What is a 'belly' in a sewer lateral?

• AA type of pipe joint.
• BA sag in the pipe that holds water.
• CA specialized fitting for steep drops.
• DA vent pipe for sewer gases.

When tapping into a city sewer main, what fitting is typically used?

• AA standard tee fitting.
• BA wye or saddle.
• CA 90-degree elbow.
• DA straight coupling.

Why might a septic system fail during heavy, prolonged rainfall?

• AThe tank shrinks in the cold.
• BThe soil becomes saturated.
• CThe pipes expand in moisture.
• DThe bacteria work too fast.

What is a common sign that a seepage pit has failed?

• AClean water in the house pipes.
• BSewage backing up into drains.
• CIncreased water pressure.
• DFaster draining sinks.

In trench excavation, what does 'sloping' refer to?

• ALaying the pipe at an angle.
• BCutting walls back at an angle.
• CThe grade of the yard.
• DDriving heavy equipment down a hill.

What is required for workers exposed to traffic while digging a sewer lateral in a street?

• ADark clothing at night.
• BHigh-visibility vests.
• CA megaphone for alerts.
• DRunning shoes for quick escapes.