How To Extend The Life Of Septic Tanks

About 25% of homes in North America utilize septic tanks. These are small self contained waste treatment systems, most commonly used in areas lacking access to sewage mains furnished by local governments. These systems should function for 50 years or more with proper maintenance, and certain preventive measures.

These systems usually function as the waste treatment plant for a single family home. Their main component is an underground tank with a capacity of 1,000 gallons (4,000 liters) to 2,000 gallons (7,500 liters). Waste from the home is fed into a tank by way of an inlet waste water pipe.

Inside waste separates as solids settle to the bottom and scum rises to the top, leaving liquid effluent in between. This clarified effluent exits, usually by means of gravity seeping into a downhill drain or absorption field. Here it will percolate through the soil, eventually evaporating or reaching groundwater in a filtered state.

It also can exit toward an uphill drain field by means of a lift pump. This is most commonly done in situations where there is no suitable downhill location for the drain filed, such as with lakefront property or nearby property lines.

The solid waste sediment that remains trapped in the tank is degraded and digested by bacteria in an anaerobic environment. Periodically, usually every 1 to 3 years this sediment should be pumped from out and carried away. If this is not done and the tank fills with solids, they and waste that has not decomposed, will flow directly into the drain field clogging the soils so that they will not allow water to penetrate and seep away. This can be an expensive problem to remedy.

In fact, system failures are much more likely to be failures of these soils to perform their task, than for the tanks to fail in some way. These soils can also be clogged by small lint particles from washing of laundry. These particle are small and remain in the effluent, rather than settling to the bottom of the tank, and are deposited into the drain or absorption field soils. This is especially problematic with synthetic fibers such as polyester and nylon, since they are not biodegradable and not permeable.

The permeability of the drain field can also be affected when the area is covered with some hard surface. This could be asphalt paving, concrete, or compacted soil from vehicle traffic, or even playground compacting. These will cause rain to run off rather than percolate through the area.

Too much saturation of the area can also prevent the effluent from be absorbed. This may result after heavy rains in the area, or when too much water is run through the system in a short period of time.

Various types of failures can occur within the septic tanks themselves. Excessive amounts of non biodegradable substances, like cooking oils or hygiene products placed in the system can clog the tank. Excessive amounts of bleach, pesticides, herbicides, paints, or solvents will kill the tank's bacteria culture, resulting in a dead system, and stopping of the degrading process. The most common failure, however, is in the drain field and it's soils.