Cost of a New Septic System

The cost of installing a septic system varies by region and equipment choices

By Robert Ferguson

Photo by iStockphoto.com

Septic tanks are on-site systems where household sewage is treated and disposed of. Sewage flows into a holding tank where bacteria break down waste. Undigested solids settle to the bottom of the holding tank and the effluent "gray water" drains into a leach field where it is safely returned to the environment.

Considerations

Consider the costs associated with a septic system vs. connecting to city or county sewage if applicable. Location is the next thing to consider when installing a new septic system. Do not install septic systems close to private wells, streams, pond, lakes or other natural water sources. Locate the leech field in an area where it is least likely to be disturbed and away from any vehicle activity.

Working Components

Components of a gravity-fed septic system are a holding tank, distribution box and a leach field. Baffles are incorporated in the holding tank's design that eliminate solid "sludge" that sinks to the bottom and prevents scum that floats to the surface from entering the leach field. The distribution box moves the effluent to the designated leach drain field through a network of perforated underground pipes. The leach field absorbs the effluent and acts as a filter to remove any remaining traces of solids that may have slipped through the baffles.

Costs

The costs to install a septic system vary from region to region. Average installation costs for a standard gravity fed system ran from $3,000 to $5,000 as of February 2010. The price can vary depending on the terrain, type of soil and access to the installation site. Other types of systems such as cluster systems and engineered systems that include mounds, sand/peat filters and aerobics can exceed $15,000.

Maintenance Costs

The septic system's holding tank periodically requires pumping and inspection. Some contractors recommend pumping every one to three years; others say a properly installed septic system can go 20 years or longer without service. In any case, the average pumping costs ranged between $150 to $300 as of February 2010 and will vary depending on location and economic conditions.

Benefits

Septic systems, when properly used and maintained, can dispose of household sewage with little effect on the surrounds environment in communities where there is no municipal sewer system.