Proposed EPA rule reinterprets agricultural storm water exemption

Storm water runoff from agricultural fields is explicitly exempt from the Clean Water Act. In the proposed rule EPA refines the definition of that rule to limit the scope of the exemption.

Land receiving manure will only qualify for the agricultural storm water exemption if you are using proper agricultural practices under the proposed rules. If you fail to properly manage the field you would lose your agricultural storm water exemption and could be fined for a point-source violation under the Clean Water Act.

Clearly covered by this interpretation of the rule are all aspects of manure application including the amount of manure applied, phosphorus-based manure management, timing of manure application, setbacks for surface water protection, and restrictions to land application to saturated or snow-covered land.

There is potential for a farmer to lose the storm water exemption for failing to adopt management practices unrelated to manure management but consistent with what EPA views as proper management. For example, could a farmer void the exemption if soil erosion was above the value recommended by the Natural Resources Conservation Service?

The new rules propose that the permit nutrient plan specifies the field management practices needed to retain agricultural storm water exemption. If these practices are not fully effective then EPA reserves the right to modify the permit nutrient plan to include additional management practices to protect water quality .