Download Oklahoma DEQ Certified Installer of Onsite Wastewater Systems license Questions And Corre and more Exams Water and Wastewater Engineering in PDF only on Docsity!
Oklahoma DEQ Certified Installer of Onsite Wastewater
Systems license Questions And Correct Answers Plus
Rationales 2025.
- What is the minimum separation distance required between a septic tank and a private water well in Oklahoma? 50 feet Oklahoma DEQ rules require at least 50 feet to protect water sources from contamination.
- Which soil texture is generally best suited for a standard septic system absorption field? Loamy sand Loamy sand provides good permeability and treatment capability for effluent.
- What is the main purpose of a distribution box in an onsite system? To evenly distribute effluent to the lateral lines A distribution box helps maintain equal flow to all parts of the drain field.
- Who is responsible for obtaining the necessary permits before installing an onsite system? The property owner or the installer The installer typically assists the owner, but both share responsibility.
- Which factor would require an alternative onsite system design? High groundwater table High water tables can interfere with treatment and require alternative solutions.
- What is the minimum setback distance from an absorption field to a property line? 10 feet This setback helps prevent encroachment and possible disputes.
- How often should a conventional septic tank be pumped? Every 3-5 years Regular pumping extends system life and prevents failures.
- Which test determines the soil's ability to absorb wastewater? Percolation test The perc test measures how quickly water drains through soil.
- When should the installer notify the DEQ for a final inspection? Before covering any part of the system Inspection must occur while components are visible to verify compliance. 10.What is the maximum slope allowed for a standard drain field site? 12% Excessive slopes can cause runoff and uneven distribution of effluent. 11.A soil horizon with mottling indicates what condition? Seasonal high water table Mottling shows fluctuating groundwater that could affect system performance.
19.What happens if an installer operates without a valid certification? They may face fines and license suspension Unlicensed work violates state law and carries penalties. 20.Which maintenance activity is the homeowner’s responsibility? Monitoring for surface discharge Owners must ensure there is no surfacing effluent. 21.When must an installer renew their Oklahoma DEQ certification? Annually Certification is valid for one year and must be renewed to stay compliant. 22.What should be done if bedrock is encountered during excavation? Stop work and consult the soil profiler or DEQ The system design may need to change if site conditions differ. 23.What is the minimum trench width for lateral lines? 18 inches This ensures enough area for effluent distribution and soil contact. 24.Which type of onsite system is used for poor soil conditions? Aerobic treatment unit (ATU) ATUs provide additional treatment for challenging sites. 25.Which component must be watertight to prevent groundwater contamination? Septic tank Leaks can cause contamination and system failure.
26.Why is it important to divert surface water away from the drain field? To prevent oversaturation Excess water can reduce the soil's absorption capacity. 27.What should you do if the soil fails the percolation test? Consider an alternative system design Different systems are available for marginal soils. 28.How often should an aerobic system be inspected? Every 6 months More frequent inspections are required for mechanical systems. 29.What is the minimum setback from an absorption field to a stream? 50 feet This protects water bodies from contamination. 30.Which factor does NOT affect the size of an absorption field? Color of house siding Only soil, flow, and loading rates affect size. 31.Which installation practice is prohibited? Installing during heavy rain Wet conditions can compact soil and damage trenches. 32.What is the maximum depth for a standard trench? 30 inches This depth ensures aerobic conditions for treatment. 33.Who enforces onsite system rules in Oklahoma? Oklahoma DEQ
41.Why are risers recommended on septic tanks? For easy access to the tank for maintenance Risers make inspections and pumping safer and easier. 42.Which local factor can override general DEQ rules? Stricter local health department requirements Local codes may be more stringent than state rules. 43.Which soil color is best for treatment? Brown Brown soil indicates good aeration and drainage. 44.Which practice protects an absorption field? Keep vehicles off the drain field Driving over it compacts soil and damages pipes. 45.What should be done with effluent if an aerobic system alarm sounds? Contact a licensed maintenance provider immediately Alarm indicates a malfunction needing prompt attention. 46.What is the minimum setback from a septic tank to a building foundation? 5 feet This protects the structure from leaks and maintenance issues. 47.Who approves an alternative system design? Oklahoma DEQ The DEQ must review and approve non-standard designs.
48.Which sign must be placed on an ATU control panel? Manufacturer’s operation and maintenance instructions Instructions must be visible for reference. 49.What should be done with excavated soil during installation? Stockpile away from trenches Prevents backfill contamination and compaction. 50.What is the best way to prolong the life of an onsite system? Routine inspections and maintenance Proper care prevents costly failures. 51.When is it acceptable to discharge untreated sewage to the ground surface? Never Discharging untreated sewage is illegal and poses health hazards. 52.What is the main purpose of the baffle in a septic tank? To prevent scum and solids from leaving the tank Baffles help keep solids in the tank for proper settling. 53.What should be done if infiltration of rainwater into the system is suspected? Inspect and repair tank and pipe seals Infiltration can overload the system and cause failure.
61.When is chlorination required in an onsite system? For disinfection in an aerobic system Aerobic systems often use chlorine to disinfect effluent. 62.What is the recommended slope for gravity flow pipes from the house to the tank? 1/4 inch per foot This slope provides sufficient flow velocity to prevent clogging. 63.What should be done if a system backs up into the house? Stop using water and call a licensed professional Backups indicate serious problems needing immediate attention. 64.Which component helps prevent freezing of lateral lines? Proper burial depth Lines buried below frost line reduce freezing risk. 65.Which situation may require a pump tank? When the absorption field is uphill from the septic tank Pumps are used to move effluent to higher elevations. 66.Why is monitoring of alternative systems required? They have mechanical parts that need regular checks Regular monitoring ensures continued proper operation. 67.Which condition could cause lateral line ponding? Excessive daily water usage Too much water can overload the field and cause surfacing.
68.What is the main function of the soil in an absorption field? To filter and treat effluent Soil microbes break down contaminants during percolation. 69.Why must grease not be dumped into a septic system? It clogs pipes and reduces tank capacity Grease solidifies and floats, causing blockages. 70.Which construction detail extends the life of an absorption field? Install inspection ports on laterals Ports allow monitoring of effluent levels and distribution. 71.What is the minimum distance between parallel lateral lines? 4 feet This spacing ensures proper distribution and prevents overlapping flow. 72.Why should downspouts not drain into the septic system? They can flood the system Excess stormwater overloads the tank and drain field. 73.What type of soil is least suitable for a conventional system? Clay Clay drains poorly and is prone to ponding. 74.Which feature is critical when installing a pump tank? Alarm system for pump failure Alarms warn the owner of malfunctions before backups occur.
82.Which household practice protects the system? Using water-saving fixtures Conserving water reduces hydraulic load. 83.How often should effluent pumps be tested? Every 6 months Regular testing ensures reliable operation. 84.Which inspection step must be done before backfilling? Check pipe grade and connections Fixing issues later is much harder once buried. 85.Which item is acceptable for septic tank cleaning? Licensed septic pumper truck Only licensed professionals should pump tanks. 86.What is the purpose of an inspection port? To monitor liquid levels in the field Helps detect early signs of clogging or failure. 87.Which problem can result from overuse of garbage disposals? Excess solids entering the tank More solids mean more frequent pumping is needed. 88.What is the recommended depth of lateral trenches in sandy soils? 12 to 24 inches Shallow placement maintains aerobic conditions.
89.Why are site sketches important for DEQ permits? They show component locations for compliance and inspections Clear records help future maintenance and troubleshooting. 90.What should be done with old system components during replacement? Remove or properly abandon them Abandoned systems must not pose a hazard. 91.What is the first step before any excavation? Call OKIE 811 for utility locates Prevents dangerous strikes of buried lines. 92.What is the purpose of a valve box? To access and adjust system controls Valve boxes protect and allow access to valves. 93.Which site condition requires soil replacement or amendment? High clay content Adding sand can improve percolation in some cases. 94.When must a new system be re-inspected? After any major repairs or modifications Ensures the system still meets standards. 95.Which system type uses a blower to supply air? Aerobic treatment unit Blowers provide oxygen for aerobic bacteria.
- Which type of pump is most common in onsite systems? Submersible effluent pump These are durable and designed for wastewater use.
- What is the main risk of undersized tanks? Solids enter the field more easily This clogs laterals and shortens system life.
- Why is backfill compaction important around tanks? Prevents tank shifting and settling Proper compaction keeps tanks stable.
- What does a mounded area over the field indicate? Elevated sand mound system Used where natural soil depth is insufficient.
- Which sign means a septic tank is failing? Tank is full of solids above the outlet baffle Excess solids can damage the drain field.
- When is an effluent filter cleaned? During routine tank pumping This maintains proper flow and protection.
- Why must installers keep installation records? Proof of compliance and future reference Records protect the installer and owner.
- What is the purpose of a recirculating sand filter? Additional effluent treatment Sand filters improve treatment when soils are poor.
- How can construction traffic damage a system? By compacting soil and crushing pipes Heavy equipment must be kept off field areas.
- Which component must be watertight? Pump tank Leaks can cause system failure and pollution.
- What is the effect of poor soil grading? Water ponding around the system Standing water affects treatment and infiltration.
- Which inspection should occur after installation? Final inspection before backfill DEQ must verify proper installation.
- What is the minimum distance between a drain field and a cistern? 25 feet This protects potable water from contamination.
- How can installers prevent trench cave-ins? Use shoring or benching if trenches are deep Protects worker safety during excavation.
- Which condition requires system replacement? System discharges effluent to surface regularly Surfacing sewage violates regulations.
- What is required before abandoning an old tank? Pump and fill with inert material Prevents collapse and safety hazards.
- Which practice reduces risk of freezing? Insulate exposed pipes and tanks Protects against freezing during cold weather.
- What is the proper response if the soil profile is incorrect? Stop work and contact the designer/DEQ The system must match approved design.
- How is effluent flow balanced in multiple trenches? Use level headers or distribution boxes Balances flow to prevent overloading sections.
- What is the purpose of a drop box? Step down effluent to lower laterals Used on sloped sites for step-down distribution.
- Which inspection step protects the environment? Leak test tanks and connections Ensures no untreated sewage escapes the system.
- What should be done if a lateral line becomes clogged? Jet or replace the line as needed Clogged lines can cause surfacing effluent if not cleared.
- Which soil condition may require curtain drains? Excessive groundwater flow Curtain drains intercept and redirect subsurface water.
- What is the function of an inspection tee? Access for cleaning and inspection Tees help maintain flow paths clear.
- How deep must a tank be buried to avoid frost in Oklahoma? Below local frost line Prevents freezing of sewage in the tank.
- What must be used to seal risers to tanks? Watertight gaskets or sealants Prevents infiltration and exfiltration.
- Which condition indicates a failed absorption field? Strong sewage odor and soggy ground These are classic signs of failure.
- Why are low-flow toilets recommended? Reduce wastewater volume Less water means less hydraulic load.
