How a Septic System Works
In a typical septic system, household wastes – including discarded food scraps, laundry water, cooking oils and grease – flow to a watertight septic tank, where they are decomposed by bacteria.
Inside the tank, the majority of the waste decomposes into sewage water, while heavier solids settle to the bottom and accumulate as sludge. Other lighter particles – including grease and oil – rise to the surface and form a scum. The decomposed sewage water then flows from the tank, through a distribution box and into a drainage field – a series of perforated pipes laid below ground in a bed of gravel. The liquid leaches out through the gravel and is further purified as it percolates through the soil.
The more complete the decomposition of your household waste the more efficiently and trouble free a septic system functions.
When a septic system is overloaded or not properly maintained, the bacterial decomposition can slow or stop, causing untreated liquid and solid wastes to overflow into the soil. Excessive use of bleaches, disinfectants and caustic or acid drain cleaners also deters the bacterial action of the system, and greases and solids can build up until they choke the system and block the flow of the liquid into the soil. When this happens, the drainage field may have to be dug up and replaced – a costly undertaking.
Septic systems cannot dispose of all the material that enters the system. Solids that are not broken down by bacteria begin to accumulate in the septic tank and eventually need to be removed. The most common reason for system failure is not having these solids removed on a regular basis. Seepage from inadequate or failing septic systems can contaminate both ground and surface waters. Malfunctioning septic systems are one of the leading causes of groundwater pollution.
Wastewater contains several undesirable pollutants. Pathogens such as viruses or bacteria can enter drinking water supplies creating a potential health hazard. Nutrients and organic matter entering waterways can lead to tremendous growth in the quantity of aquatic microorganisms. Metabolic activity of these microbes can reduce oxygen levels in the water causing aquatic life to suffocate.
Most septic systems are conventional systems that use gravity to distribute the effluent from the tank. When site conditions are not appropriate for a conventional system, other types of systems, such as low pressure distribution or mound systems are sometimes used.
Septic tanks typically use one of four drainage system designs to dispose of effluent:
DrywellsDrywells are plastic or concrete perforated tanks for discharging effluent into large, fabric covered, gravel-filled holes: Leach Pits. Drywells are a passive (no pump) solution for small/odd lots where a long leach field is not possible or desired. Pits take advantage of surface area around sides to dispose of large amounts of water in the right soil and capability to accept large surges at one time. |
Drain FieldsDrain Fields are trenches (or rectangular beds) dug in yard and filled with 6' to 24"of gravel and a four inch diameter perforated pipe. The pipe-in-gravel drain line is covered with geo textile fabric (landscaping weed barrier) and then backfilled with sand and a 6" to 24" of native soil. Gravity sends effluent to the drain field (1/8 inch per foot drop minimum) and dispersed into soil evenly (drain field pipe is level). |
Stone TrenchesStone Trenches are a system consisting of four inch pipes installed horizontally in 3' wide trenches. Typically an alternator valve divides the system of trenches in half. The pipes are installed on 6" to 24" of 6A stone as specified on the permit. The pipes are perforated to allow the effluent to drain on the stones and surrounding soil. More stone is placed around and onto the pipes, followed by a layer of filter fabric, than 6' to 24" of soil cover. Specific requirements vary with each permit. |
Pressurized SystemsPressurized Systems make use of an electric pump to force effluent into mounds, trenches, beds or chambers. Even distribution of effluent is key to smaller drain field sizing and better treatment of the waste water. Poor soil percolation sites (high water table) often require pressure distribution sand mounds with two inch diameter pipe drilled with 1/4 inch holes every two feet, or so. Drip systems utilize small nozzles for even more uniform distribution of waste water. |
Alternator ValveThe Bull Run Alternator Valve is designed to alternate flows to different absorption areas of the sewage disposal system. Using a special tool at ground level, the homeowner switches the valve annually from one absorption area to another. The user has no contact with the waste water because the valve is leak proof. |
Maintaining your septic systemProper septic system maintenance will aid in avoiding costly and unnecessary expense. |
Your septic system should be properly maintained to assure years of trouble free service.
Aqua Vac recommends every 2-3 years as does the Fraser Health Department. Frequency may change depending on high household water usage and if there is a garbage disposal installed.
Failing septic systems can:
• Endanger your family's health.
• Pollute the environment.
• Reduce your property value.
• Be expensive to repair.
Warning signs of septic system problems:
• Wet spots in the yard.
• Slow draining toilets or drains.
• Gurgling sounds in your drains.
• Sewage odors.
You've spent thousands of dollars on your home and landscaping, lack of maintenance on your septic system will allow solid waste materials to flow into your drain field eventually clogging it.
Ways to Prolong the Life of Your System
There are many ways to prolong the life of your septic system and lengthen the period between pumping. Household water use directly controls how quickly waste travels through a conventional system. Wastewater that enters the tank requires time to allow the solids to settle to the bottom. The higher the volume of water that is introduced to the system, the less opportunity the wastewater has to settle in the holding tank and the less opportunity the bacteria have to break down the solids. Therefore, limiting the use of water in the home will go far in prolonging the life of the system.
Reduce Household Water Use
• Use water-saving shower heads and faucet aerators.
• Install low-flow toilets.
• Repair leaking toilets (place a few drops of food coloring into the toilet tank to detect water leakage into the bowl).
• Make sure sump pumps and roof drains are not connected to the sewage system.
• Use front load washers and space out the time between washings.
• Watch What Goes Down the Drain.
• Controlling what goes into the water that enters the system is just as important as reducing the amount of water that flows into the system.
• Never dispose of toxic or hazardous chemicals by dumping them down the drain as they have the potential to contaminate groundwater.
• Refrain from putting any plastic, cloth, or unnecessary paper products into the sewage system.
• Avoid using garbage disposals as they accelerate the accumulation of solids in the septic tank.
• If a garbage disposal is installed, septic tank pumping frequency should be increased.
Septic Inspection
Selling Your Home? We Uncover and Inspect Septic Systems for Real Estate/Mortgage Evaluations Components of our Certified Septic System Inspection.
1. Examine inside the septic tank: Aqua Vac certified inspectors open the tank, examine the inlet and outlet baffles and determine the volume of the treatment tank. The tank is then inspected for cracks, corrosion and leakage. We also verify that both baffles are in place. In addition, our inspectors also check the waste levels inside the septic tank.
2. Inspect the conveyance system: Aqua Vac certified septic inspectors examine the distribution box or alternator valve for leakage, cracks and corrosion. Our inspectors also make sure that the distribution box is level. Any cracks or corrosion will be identified.
3. Check the Absorption Field: Aqua Vac septic inspectors visually inspect pipes leading to the absorption/drain field. The inspection also includes a flow test where dye is introduced into the septic system. This test will simulate normal septic usage and enable our septic inspectors to observe drainage. Various points in the absorption area are uncovered allowing for proper inspection of the pipe and stone. Aqua Vac inspectors visually inspect the surface area to locate signs of system backups and probe underground to check for drainage levels.
4. Drinking well water samples can also be drawn upon request and sent to our lab for analysis.
5. Comprehensive and Easy to Read Reports: Our inspection provides Written Reports stating clearly the overall condition of the septic system and what problems may be present. If a water analysis is required, the lab report will also be provided.
Septic Tank Locating.
Aqua Vac technicians have years of experience in locating septic systems. However, occasionally a septic tank is difficult to locate underground. When this problem occurs Aqua Vac uses the latest technology in electronic locating devices. Our electronic locators can pinpoint the location of a septic tank through the use of a sound device that is flushed down the toilet or mechanically inserted into the septic tank via the main line cleanout or another access point. A technician than uses the receiver above ground to receive the signal being transmitted via the sound device in the septic tank.