The most common system you can use to dispose of wastewater is a septic system. Whether or not you decide to recycle graywater, you will still need a septic system to get rid of the blackwater from your home.
There are four main components to a typical septic system:
A pipe to carry the waste from the home
The actual septic tank to start the digestion process
The drain field to spread out the wastewater
The soil with microbes to do the final filtering and cleaning of the water
Once the used water enters the system, the pipe carries the water and accompanying waste out of your home and into the working parts of your septic system. The septic tank is actually a watertight tank that is buried several feet underground. Septic tanks have concrete manhole-size lids that generally sit at ground level, providing easy access for cleaning, inspection, and pumping the tanks.
Tanks can be made of concrete, fiberglass, or polyethylene. When wastewater comes into the tank, the solids settle to the bottom. This material is known as sludge. The oil, grease, and other nonsolid components rise to the top and are known as scum. This separation allows for a partial decomposition of the solid material. This decomposition is aided by a variety of different bacteria and enzymes that naturally break down the human waste in the tank and help it dissolve back into the earth, so you are not just accumulating a massive amount of refuse.
Sludge and scum are prevented from leeching out of the septic tank by a T-shaped outlet design that holds in the more solid materials and allows the water to seep into the drain field. You should use additional screens throughout the system to ensure that the solids do not make it into the drain field.
Once wastewater has been separated from the solids, it exits the septic tank into a drain field to complete its treatment in the soil. Wastewater is fed into the drain field every time new blackwater and graywater are introduced into the tank.
The soil surrounding the drain field is essential in removing contaminants from your wastewater before it is returned to the groundwater. The microbes in the soil remove harmful bacteria, viruses, and nutrients from the wastewater. This is accomplished by the wastewater filtering through the drain field.
Have your soil tested to be sure it is porous enough to allow natural filtration. Once installed, your septic system should be inspected every three years and pumped out every three to five years. However, maintenance of the septic system should be an ongoing process.
The death of beneficial bacterial colonies in your septic tank can be lessened by changing from potent chemical cleaners to organic cleaning products, which are not quite as harsh on the bacteria that work in the tank.
Unfortunately, the bacteria and enzymes that eat away the sludge and scum are easily destroyed by bleach or paint thinner entering the system. You can restore the natural enzymes in the system quickly and inexpensively. All you have to do is buy a box or package of the enzymes made for septic systems and flush it down one of the toilets in your home. Some have found that adding brown sugar with the enzymes helps to increase their viability. You should add enzymes to stimulate the function of your septic tank about once a month for optimal performance.