Infiltration: Testing

Percolation testing

The preferred testing period is during April and May. If testing is conducted between June 1 and December 1, the soil should be soaked for 24 hours prior, to simulate field saturated conditions.

1. If uniform soil texture is observed in the proposed location, at least three percolation test holes should be prepared. If the soil texture changes within the area, make at least two test holes in each soil texture. All test holes should be uniformly spaced across the proposed area.
2. Test holes should be between 150 - 200 mm in diameter, and penetrate to the depth of the proposed BMP. Observations should be made on the extracted soil and variations recorded.
3. The lowest 300 mm and the bottom of the test pit should be scarified, and the loose material removed.
4. A mesh bag containing about 1L of pea gravel may be lowered into the pit, to prevent scouring of the base. Attaching a line to the bag allows it to be removed and reused.
5. Carefully pour 6 L of clean water into the base of the pit. A hose is recommended to prevent washing out or erosion of the sides.

• In sandy soils, where half the depth of water percolates within 30 minutes, ....
• Otherwise,

Calculate the percolation rate

http://www.extension.umn.edu/environment/housing-technology/moisture-management/how-to-run-a-percolation-test/index.html

Best management practice. State of the art methods or techniques used to manage the quantity and improve the quality of wet weather flow. BMPs include: source, conveyance and end-of-pipe controls.