8,255
edits
Changes
Jump to navigation
Jump to search
Line 67:
Line 67: − ===Infiltration Testing===+ Line 73:
Line 73: − +
→Infiltration Testing
*For sites with multiple infiltration BMPs, each with footprint surface area < 50 m<sup>2</sup>, a minimum of one test pit is required and one soil boring per infiltration BMP location is recommended.
*For sites with multiple infiltration BMPs, each with footprint surface area < 50 m<sup>2</sup>, a minimum of one test pit is required and one soil boring per infiltration BMP location is recommended.
==Infiltration 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.<ref>http://www.extension.umn.edu/environment/housing-technology/moisture-management/how-to-run-a-percolation-test/index.html</ref>
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.<ref>http://www.extension.umn.edu/environment/housing-technology/moisture-management/how-to-run-a-percolation-test/index.html</ref>
*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.
*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.
*The lowest 300 mm and the bottom of the test pit should be scarified, and the loose material removed.
*The lowest 300 mm and the bottom of the test pit should be scarified, and the loose material removed.
*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.
*A mesh bag containing about 1 L 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.
*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.
*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 infiltration rate
*In sandy soils, where half the depth of water percolates within 30 minutes. Otherwise, calculate the infiltration rate