Hello again, we are working on a project for which we are installing a sediment basin. According to EPA we could use the calculation of 3600 ft3 / acre drained to size it. Most of the drainage area will remain undisturbed since it will be a preserved area. Diverting the water from undisturbed areas is quite difficult because of topographical constraints. We found in a manual that from undisturbed areas, we could use a runoff value of 500 ft3/acre drained in addition to the 3600ft3/acre drained of disturbed areas. Would doing this be compliant with EPA's regulations? We are outside the US and not very familiar with these regulations. Thanks!