As previously reported by AGC, flow-based clean-up plans (called TMDLs or Total Maximum Daily Loads) were the subject of a 2013 federal court ruling in Virginia where the court decided that EPA could not regulate stormwater flow into the Accotink River through a TMDL, because the Clean Water Act (CWA) only allows regulation of "pollutants." Additionally, in late 2014, AGC reported on an updated EPA policy memo on stormwater permitting issues that removed the language on the use of flow as a surrogate. But there are indicators that the EPA still wants to regulate flow—and some state environmental agencies and local governments appear to be following suit.

AGC has observed the EPA using a "permit-by-permit" approach to require stormwater retention and the use of green infrastructure—such as permeable pavement and rain gardens—as an alternative (albeit backdoor) route to regulating stormwater flow. (This comes after the EPA abandoned work on a nationwide post-construction rule for stormwater runoff, which was expected to set retention standards for all new construction and redevelopment.) It appears that states and local governments are mandating these practices as well. AGC previously shared a "toolbox" of resources to help you respond. What has been happening in your area? Are your members concerned about mandates on stormwater retention, flow or impervious surface area? Please contact Leah Pilconis at pilconisl@agc.org if you would like to continue the discussion.