How to Run a Percolation Test Part 2
The following steps outline the procedure for performing a Percolation Test. This is part 2 in our series on How to Run a Percolation Test. These steps should follow the previous steps taken from part 1 of our series on How to Run a Percolation Test.
- Prepare in advance of the test one wooden stake for each 2-foot test hole. Three nails should be pounded into each stake. The first nail should be three inches from the bottom of the stake, the second nail must be exactly six inches above the first nail, and the third nail must be exactly 20 inches above the second nail.
- On the morning of the percolation test (the day following the presoak), the test holes should be cleaned out. Any loose soil or silt that accumulated at the bottom of the holes during the presoak should be removed. One of the stakes prepared per the instructions in #4 above should be driven into each hole so that the first nail rests on the bottom and the stake stands by itself.
- At a time previously arranged between the perc tester and the Health Department technician, each test hole is filled with water to the level of the second nail on the perc test stake (which should be exactly six inches). NOTE: Do not wait for the technician to arrive to start the test. After one hour, the perc tester shall measure how far the water has dropped in each test hole. The holes are then refilled with water to the level of the second nail. This process is repeated for at least three more hours. The Health Department technician will take the measurements for the second and all readings after that.
- In very porous soils, the water in the test holes may seep away in less than an hour. When this happens, the Health Department technician may go to half-hour or even ten-minute readings. A test may also be extended to five or more hours if the last three readings are inconsistent.