What is a perc test and do I need one before buying land in South Carolina?

A perc, short for percolation, test checks how well the soil on a parcel absorbs water. The result determines whether, and what type of, septic system can be installed on a site that does not have access to municipal sewer.

This matters most for buyers who plan to build without sewer access. If you are buying a parcel purely to hold, or one that already has sewer access, a perc test may be far less relevant to your decision.

A few things worth understanding:

• Failing a perc test does not automatically kill a deal. It can instead limit the type of septic system that will work, or shrink the area of the lot that is actually buildable.
• Results can vary by specific spot tested on a larger parcel, so a failed test in one location does not necessarily mean the entire parcel fails.
• This is generally something to have done, or at least request results for, during a due diligence period rather than assuming a favorable result.

Rather than guessing based on how the soil looks, or relying solely on general soil maps, get an actual perc test done by a qualified tester if building without sewer is part of your plan. Making an offer contingent on a satisfactory perc test result is a reasonable way to protect yourself if this has not already been done.