Septic Tank Costs

The only way to get an accurate estimate of septic tank costs is to send your approved septic design to several licensed septic system installers. The following prices are simply to give you an idea of what kind of money you may be dealing with. Septic tank prices will vary around the country according to local labor and material rates. There are several kinds of costs associated with a new septic tank:  installation costs, maintenance and repair costs such as pumping or cleaning out the tank, and the replacement costs if things go wrong. Proper steps taken in the installation and maintenance will prevent most of the replacement costs.

Cost Estimates

A standard or conventional gravity system for a three bedroom house on a level site in good soil can vary greatly depending on where you live but it should be roughly between $1,500 to $4,000 depending on who you have to install it.  If plastic vaults are used, the cost will be on the higher side of this range. Vault systems will usually be smaller than gravel designs, but they cost more than the relatively inexpensive drainrock.

The prices for tanks, drain gravel, vaults and pipe doesn't vary as much from place to place, but harder to drain soils and extra bedrooms will cost more. Fine silty soils require more drainfield and are more risky to build due to slightly higher failure rates.  The drainfield vaults are around $25 to $40 each and good quality clean drain gravel is around $9 - $12 per ton if the pit is not to far away. Minimum tank size is determined by state and local laws, so check these before you make your decision. Concrete tanks are the most practical choice, and these run around $500 -$700 for a 1000 gallon tank delivered to a home within 50 miles or so. 1250 gallon tanks are preferred by some homeowners and will be more expensive by close to $100.

Pressure systems will cost a lot more in places where they are new or scarce with only a few excavators choosing to put them in.  As pressure systems become more popular in an area, the prices slowly come down. $3000 to $5000 is an average range for a small, simple pressure system or bottomless sand filter (which requires no vinyl liner, concrete or plywood walls needed).  In many cases you will also have to hire an electrician to wire a pressure system into the house, although some places will allow the installer to do this.

The strictness of health codes in your area, the septic systems design, and the number of licensed installers in your area, will all determine the prices of the estimates you receive. In certain parts of the country the figures given here can increase by up to 50%.

The typical annual maintenance costs of a new septic system, drainfield or mound system range from $30 up to $500, though few ever go this high unless it involves replacement costs of pumps. Standard, gravity-fed tank and trench systems typically only need to be pumped/inspected every 1-3 years and will cost $75 to $150 if they need pumping. The annual cost of a septic system with constructed wetlands or sand and peat filters are often $50 to $1,700, depending on the discharge method and monitoring requirements.

Any type of new septic system, if it is built and used properly, has the potential to last 20 - 40 years or more. Some types of systems will need pumps replaced periodically and various other types of treatments. The proper operation, management and septic tank costs of any system are dependent on the education of the people that use those systems. Any new home owner should educate themselves as thoroughly as possible on what to do and not to do in regard to their septic systems so as to have the least expensive and trouble free septic system possible.