A perc test is a soil test to determine if the soil and groundwater conditions on a property are suitable for use as an on-site sewage disposal system. All properties not served by public water and sewer must have this test before beginning construction of any structure with plumbing. If an area of acceptable soil is found, a plat is established for the area to be designated for sewage disposal. Perc tests are performed when contemplating new construction, adding on to land already served by on-site systems, and when a system fails.
SMCHD’s Environmental Health Division conducts soil evaluations for the construction of residential and commercial septic systems. The application for a new construction perc test is available through the St. Mary’s County Department of Land Use and Growth Management (LUGM) and requires a fee. The LUGM office is located in the Patuxent Building on the St. Mary’s County Governmental Center campus in Leonardtown. The perc test application is also available for download on the LUGM Permits webpage. When a septic system fails, the health department receives applications for repair perc tests; there is no fee associated with this service.
