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What Is A Perc Test?

Learn why you may need a perc test if you're planning a new construction home. ImproveNet connects you to local professionals who can do a perc test on your land.

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People who are purchasing land to build a new construction may have to have specialized testing done before they can build. Soil testing usually has to be done to determine whether the site can support a home. Because of this, it’s imperative that any offer you make to purchase land to build a home on has a contingency clause that allows you to back out of the purchase if the soil doesn’t pass the required tests.

ImproveNet can connect you with local professionals who can take care of this soil testing for you.

What Is A Perc Test?

Perc testing, formally known as percolation testing, is a type of soil testing that’s done to determine whether the potential building site can handle the demands of a septic system. The test must be done if the proposed building site for a new construction home is in a location that can't be connected to the local sewer system.

A septic system will only work properly if the leach area is permeable enough to absorb the liquid that flows into it. The perc test is done to check the ability of the area to do this. The results of the perc test can tell you whether the septic system can be supported, and it will also provide a clue as to how many bedrooms the home can house since this is typically used as an indication of how much wastewater will flow through the pipes.

How Much Does A Perc Test Cost?

Perc testing is typically done by a professional and is normally part of a soil testing package. The median cost of this nationwide is $1,142. The average range is $947 to $1,550, with the minimum cost being as low as $400 and the maximum cost ranging upwards of $2,000.

The perc test is a fairly expensive test to conduct because it requires two or more holes to be dug down at least 2 to 3 feet and approximately 6 to 12 inches wide. Gravel has to be placed at the bottom of the hole. The test takes approximately two days to complete to check the draining rate of water that’s put into the hole. It also requires periodic checks during that time period.

Who Pays For A Perc Test?

The perc test is typically paid for by either the buyer or the seller of a property that’s intended to be used for homebuilding. If you’re considering the purchase of a lot to build a home, discuss the payment of the perc test with your real estate professional to determine what’s customary in the area. If the buyer covers the cost of the perc test, they may be able to work out a credit on the purchase price of the land to offset the out-of-pocket expense.

How Long Is A Perc Test Good For?

You’ll have to check with the local municipality to determine how long the results of the perc test are valid, but most are valid for two to five years. This varies from one location to the next. Typically, you’ll have a perc test done when you’re considering the purchase of a site. You’ll need the perc test results when you go to obtain the building permit for the dwelling.

What's A Failed Perc Test?

When a perc test shows that the ground doesn’t meet the local requirements for a septic system, there are a few things that can happen. The worst of these is that the site will be deemed ineligible for a house to be built, so you’d have to find a new site for your home.

In some cases, the area might be deemed ineligible for a gravity-fed septic system, but there’s a chance that a more intricate system, which is also a bit more expensive, might be allowed.

Another option if the perc test shows that a septic system isn’t able to be used on the site is to de-water the area. This is done by placing trenches filled with gravel strategically around the area to conduct water to other areas. You’ll need a civil or geotechnical engineer to plan this project.

Finding A Local Perc Tester

ImproveNet can connect you with local professionals who can do a perc test and can answer questions that you have, such as:

  • What is a septic perc test?
  • What do the results of the perc test mean?
  • What options do I have if the perc test fails?

Remember, it’s best to obtain at least three quotes for services from local professionals. This enables you to choose the option you feel is best for your situation. Don’t be tempted to only look at the price of the service. Instead, you should also consider the quality of the service and the reputation of the professional.

Article Topics

  • Home Services

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