What does it cost to install a septic system?

[Elisa K.]

We're looking to purchase a new home that will need a septic system.

How much will it cost to buy and install one?

[home improvement guy]

For new construction - a brand-new house with a brand new septic system - the cost will depend on the system's design and how large a house you're building.

A three- or four-bedroom house typically requires a 1,000-gallon septic tank, and the cost for the tank and installation averages between $8,000 and $15,000. For a house with five or more bedrooms, you'll most likely want a 1,500-gallon tank, and that will cost $15,000 to $25,000.

The cost to replace an existing septic system is $3,000 to $7,000, depending on the size and complexity of the job.

SPECIAL SEPTIC SYSTEM CONSIDERATIONS

As you plan your septic system installation, consider what other construction is going on around the property. You'll need heavy equipment to dig out the system and lower the tank into the ground. You don't want such equipment to drive across or park on a freshly poured driveway. At the same time, there should never be any type of traffic, other than foot traffic, over a septic system before or after installation because soil compaction can prevent proper function.

In most cases, it's best to install a new septic system after the home's outside walls are finished, but before driveways, sidewalks, sod or final grading is done. After the tank is installed, you may be left with several loads of dirt you can use elsewhere on your property.

SEPTIC SYSTEMS PERMITS, INSPECTIONS, TESTS

You'll need permits and inspections and, possibly, environmental testing for a new septic installation. Your local health department determines what and how many permits are needed. Septic system experts in your area should know what's required and how to obtain permits. However, a diligent homeowner will want to call the local health department to be clear about requirements.

Installing a new septic system can take two to five days, but that can vary more, depending on such factors as the county inspector's schedule and weather and soil conditions.

TIPS FOR HIRING SEPTIC SYSTEM PROS

Be sure to get several bids from licensed septic tank installation companies, and don't be afraid to ask about product warranties and workmanship guarantees. Only hire a contractor who has good reviews on a trusted consumer site, plenty of experience installing septic tanks and who can provide proof of appropriate licensing, insurance and bonding.