On September 29, 2022, Region 3 ECAD issued an Administrative Order on Consent (AOC) to Washington County, MD (Washington County) requiring specific work to achieve compliance with Maryland's NPDES General Permit for Discharges from Small Municipal Separate Storm Sewer Systems (the MS4 Permit). The agreed upon AOC is the final stage towards addressing numerous areas of noncompliance with the MS4 Permit, which were identified by EPA during a 2020 remote/off-site NPDES permit compliance audit and separate on-site compliance inspection of Washington County's MS4 Program. Subsequent to EPA's issuance of a November 2020 inspection report, Washington County undertook significant work to address several areas of noncompliance with the MS4 Permit. The AOC addresses the following single area of noncompliance which remains outstanding: failure to inspect, require maintenance and, as necessary, perform required maintenance of deficient post-construction stormwater infrastructure to ensure proper construction and maintenance post-construction stormwater infrastructure. The primary environmental significance of this matter relates to on-going noncompliance with important aspects of Maryland's NPDES MS4 permit program. MDE has been provided notification of this AOC. Washington County has not been identified as an area of EJ concern.