Hydraulic Load Test
Homes that are unoccupied for more than one week or where a change in occupancy is expected need to have a hydraulic load test. When a home is unoccupied the septic system is considered "out of service". The only way to determine the condition and operation of an out of service system is to perform a hydraulic load test. We perform hydraulic load tests following PSMA/NOF protocol. We bring the water for the test to the site rather than using the homeowners well as the water source.
Description of a Hydraulic Load Test (HLT)
A hydraulic load test simulates the daily flow as determined by the PA DEP and entails introducing clean water directly into the absorption area on two consecutive days. The liquid level in the absorption area is measured after the first volume of water is added. The second volume of water is added after 24 hours and the liquid level is measured again. For a satisfactory system, the second day’s liquid level must be lower or equal to the first day’s measurement and below the top of the aggregate in the trench. This would indicate that the liquid from the first day was fully absorbed into the soil and the absorption area is satisfactory.
Amount of water for a Hydraulic Load Test
Can a hydraulic load test harm a septic system? No, only the amount of water the Pennsylvania DEP says that a system should be able to handle is used. If a system "fills up" during the test the test is stopped.
A hydraulic load test is similar to conducting a perk test of the soil in that it is a way to gauge the drainage characteristics of the soil.
