How does a septic system work?
There are two main parts to the basic septic system: the tank and the drainfield.
The household wastewater flows into the tank where the average detention time is 24 hours. The tank should have at least 1,000 gallon capacity.
Three layers are formed in the septic tank.
- There are baffles or tees in the tank which keep the wastewater flowing though the tank at a level near the middle of the tank.
- Solids settle to the bottom forming a layer of sludge.
- The grease and foam float to the top forming a scum layer.
Both the sludge and scum layers remain in the tank where bacteria break them down. In time, the layers build in size. When the layers become too large and take up too much space in the tank, the tank needs to be pumped. Every 2-3 years the tank should be pumped out by a licensed septic system pumper. If the system is not pumped out when it is full of solids, the wastewater is not fully treated and solid material can be carried into the drainfield.
Solids in the drainfield can clog pipes and seal pores in the soil. When the pores become sealed with solids the water no longer percolates as it should.
The drainfield provides additional treatment of the wastewater. In the drainfield, wastewater trickles though a series of perforated pipes, though a layer of gravel, and down though the soil. The soil and soil bacteria act as a natural filters that help treat the wastewater.
How can I find the location of my septic system?
County health departments issue permits and inspect systems as they are installed. If your system has been installed in the last 20 years they may have a sketch of the layout of the system.
Septic system pumpers can usually find the tank by using a soil probe in areas where they would expect to find a tank. Tanks are usually behind the house, near the bathroom, and about 10 feet away from the foundation.
Note where your drain pipe leaves the house; this will point you in the direction of the septic tank. A search in this area may reveal the septic tank cleanout openings and shallow depressions marking the trenches. Unfortunately, the tank is usually unmarked.
- Depressions in the soil of 2-3 sq.ft. that mark a previous excavation for pumping.
- Stones, stakes, or other markers may have been left by a previous owner to mark the location of a septic tank cleanout plug.
- Pipes sticking up out of the ground, between 1' to 5' from the home, especially if they are 3" to 4" white plastic, normally mark cleanouts on the waste line between the building and the septic tank. Some septic pumping companies install a 6" to 18" "riser" pipe with a cap close to ground level which is used as a quick access port to pump the septic tank.
- Electrical boxes sticking up out of the ground might mark the location of electrical connections feeding electrical components used in some septic systems. For example, a septic tank using an effluent pump to move effluent to an uphill location.
- Circular depressions of perhaps 5ft. diameter. However, on rare occasions there may be a raised area if soils have settled away from the septic tank.
- Circular areas of less grass growth - due to lack of soil because the tanks are not buried very deep.
- Areas of more lush grass growth - if the tank is leaking effluent around itself.
How do I maintain my septic system?
Conventional septic systems last an average of 20 years. A properly constructed and maintained system can last longer. A system that is not maintained can fail in 2 years or less. Regular maintenance protects the investment and avoids replacement costs. Maintenance also protects the health of your family, the community and the environment. Replacing a failing septic system can cost upwards of $8,000 depending on system size and type, which is very expensive when compared to the cost of having the system routenely inspected and pumped out.
When systems fail, inadequately treated household wastewater is released into the environment. This can contaminate nearby wells, ground water, and drinking water sources. Any contact with untreated human waste can pose significant health risks.
Septic system maintenance is simple:
- Every 2-3 years have a licensed septic system pumper pump the solids from the tank.
- Water conservation is very important.
Knowing what not to flush is important. Never use the septic system for disposal of anything that can easily be put into the trash. This only adds to the solids build up that will eventually need to be pumped out.
- Avoid grinding up food scraps, coffee grounds, and disposing of grease and cooking oils down the drains.
- Use toilet paper that is biodegradable and approved for use in septic systems by the National Sanitation Foundation (NSF).
- Don't plant trees within 6 feet of the system, their roots will clog the pipes.
- Don't drive over or park on the septic system.
- Don't fence livestock over the septic system.
- Don't dig in or cover the drain field with concrete or asphalt. Grass should be the only cover.
- Don't pour harmful chemicals or cleansers into the system. Paints, varnishes, thinners, waste oils, photographic solutions, and pesticides can destroy the biological action in the system and pollute the environment.
How do I know if there is something wrong with my septic system?
Home owners should be alert to the following warning signs of a failing septic system:
- The ground in the area is wet or soggy.
- Sewage odors in the house or yard.
- Plumbing backups into the house.
- Slowly draining sinks and toilets.
- Gurgling sounds in the plumbing.
- Wet areas which may indicate a failing drainfield.
If one or more of these warning signs exist, the you should contact a licensed septic system pumper to have the system inspected and pumped.
I've never had any problems with my septic system, why should I pump my septic tank?
The primary function of the septic tank is to separate liquids from solids. Solids are retained in the tank after settling. Digestion of the solids occurs over time; however, the rate of solids accumulation exceeds the rate of solids digestion.
Additionally, not all of the solids are digestible. Therefore, the solids level does rise over several years. A septic tank must be pumped periodically to prevent the solids level from reaching the outlet baffle where they are carried over to the disposal field.
Was my septic system full?
Your septic system will always look "full"- this is how it is designed to work. It is at a working level when it's just below the inlet pipe. The "full" level does not necessarily mean that the tank should be pumped out, this is normally determined by the bottom sludge layer or the layer of scum (crust) on the surface.
However, if the water level is over the pipe, then it's overfull and should be pumped out (this may be an indication of further problems involving your lateral lines).
What will happen if I do not service my septic tank?
Failing to do this is like driving your car for a hundred thousand miles and never changing the oil. Disaster awaits. Thus the old addage "You can pay a little now or a whole lot more later" Dumping some miracle cure in the crankcase is not going to magically fix the car.
Basically, neglecting the system by not pumping until it backs up usually results in drainfield failure and requires drainfield replacement or new system installatiion.
Do I need to add any products (yeast, enzymes, other over the counter additives) to my septic system?
Digestion of the solids that accumulate within the septic tank is a naturally occurring process. The microbes that drive the digestion process are present in raw sewage at a high enough concentration that supplemental products are not normally necessary.
However, due to large use of antibacterial soaps and other bacteria-killing products, it may be advisable to use bacteria-boosting products.
How often should you service your septic tank?
Experts say septic systems should be pumped out every 2-3 years to insure proper operation. Sludge does not magically disappear by putting some additive in the system. After the bacteria do their work sludge is left and must be pumped out. The theory that "if it aint broke dont fix it" does not apply here.
Drainfield failure and serious expense looms ahead if you do not act. Think of it this way. If you had city sewer you would pay around $35 / mo. or $420 / yr. This cost is more than what you pay every 3 yrs to pump. You are over $840 ahead and you are keeping your system running well and you don't need city sewer.
My neighbor's aerobic sprinklers spraying, but mine aren't. What's wrong?
Most aerobic systems spray on demand, which means that when you run enough water into the system, the water level rises, raising the float, which turns on the pump. Since everyone's water usage varies, the sprinklers won't necessarily spray at the same time.
Doesn't the aerobic system grind everything up and then make it go away?
No. Aerobic systems are basically like conventional systems, except they do a better job of treating the waste. Therefore, only clear water comes out of the system. Since the aerobic system does such a good job of separating the water from the waste, all of the waste remains in the tanks, requiring the tanks to be pumped more frequently.