Perc Testing: frequently asked questions

A percolation test measures how fast water soaks into the soil of a lot. With a soil evaluation, it tells the health department whether a conventional septic system can work there.

Ideally before you close on a lot without public sewer, during your contingency period. Some counties only allow tests in certain seasons, so plan ahead.

Depending on local rules, an alternative system such as a mound or an aerobic treatment unit may be permitted. A designer can tell you which options exist for your soil.