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→Surface Infiltration Rate Testing
Surface infiltration rate testing involves estimating the saturated hydraulic conductivity (K<sub>S</sub>) of the BMP surface through measurement at several locations and calculation of an average value. A single measurement can take anywhere from 15 minutes to several hours (Erickson et al., 2013<ref>Erickson, A.J., Weiss, P.T., Gulliver, J.S. 2013. Optimizing Stormwater Treatment Practices: A Handbook of Assessment and Maintenance. New York: Springer. https://link.springer.com/book/10.1007/978-1-4614-4624-8</ref>) depending on soil or surface characteristics.
Surface infiltration rate testing involves estimating the saturated hydraulic conductivity (K<sub>S</sub>) of the BMP surface through measurement at several locations and calculation of an average value. A single measurement can take anywhere from 15 minutes to several hours (Erickson et al., 2013<ref>Erickson, A.J., Weiss, P.T., Gulliver, J.S. 2013. Optimizing Stormwater Treatment Practices: A Handbook of Assessment and Maintenance. New York: Springer. https://link.springer.com/book/10.1007/978-1-4614-4624-8</ref>) depending on soil or surface characteristics.
===Filter Bed Surface Infiltration Rate===
To evaluate surface infiltration rate using a surface ponding well during a simulated storm event, the filter media bed should be thoroughly wetted prior to the test. Measurements of filter bed drainage rate and corresponding estimates of surface infiltration rate should be made following natural or simulated storm events that deliver enough water to the BMP to pond at least 75 mm of water on the surface of the filter media bed, in an effort to consistently approximate saturated soil flow conditions.
====Calculation====
<math>{I_z \over I_0}= e^{-kz}</math>
Filter Bed Surface Infiltration Rate <math>i= {50mm \over Δ_T50}</math>
Where;
ΔT50 = Time to drain last 50 mm of surface ponded water
ΔT50 = (T2 – T1)*24
T1 = Post-storm date and time (mm/dd/yyyy hh:mm:ss) when surface ponding water level reaches
50 mm in depth.
T2 = Post-storm date and time (mm/dd/yyyy hh:mm:ss) when surface ponding is fully drained
==Natural or Simulated Storm Event Testing==
==Natural or Simulated Storm Event Testing==