The number of test pits or soil borings varies depending on site conditions and the proposed development plan. General guidelines are as follows:
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*For infiltration BMPs with footprint surface areas from 50 - 900 m<sup>2</sup>, a minimum of two test pits or one test pit and two soil borings are required at, or within 10 m of the proposed location to determine the suitability and distribution of soil types present;
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*For infiltration BMPs with footprint surface areas > 900 m<sup>2</sup>, a minimum of one test should be conducted for each 450 m<sup>2</sup> of footprint area. Tests should be conducted equidistant from each other to provide adequate characterization of the area;
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*For linear infiltration BMPs (e.g. [[bioswales]], [[enhanced grass swales]], [[infiltration trenches]], [[exfiltration trenches]]) a minimum of one test should be conducted within each soil mapping unit present along the proposed BMP location. Soil borings should be conducted every 50 m and a test pit should be conducted every 450 m; and
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*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.