On September 18, 2020, Region 3 entered into Administrative Orders for Compliance ( AOC ) with the U.S. Department of the Navy for its Washington Navy Yard and Naval Observatory public water systems. During sanitary surveys of both public water systems, EPA identified a recurring significant deficiency: Backflow Prevention Devices ( BFPs ) were not repaired or replaced within ten days of failing an inspection/test; inspection/test results were not being entered into the work order tracking system in a timely manner; and repair/replace records were not entered into the work order tracking system. To correct this significant deficiency, both systems submitted a joint Corrective Action Plan ( CAP ) that was approved by EPA in October 2016, and then revised and approved by EPA in August 2017. The 2019 sanitary survey concluded, however, that the significant deficiency persisted at each system. The AOCs require the Navy to submit a Supplemental CAP for review and implementation upon EPA approval. The Supplemental CAP shall further describe repair processes, deadlines, BFP Team roles and responsibilities, and any associated contracts. EPA has primary enforcement responsibility for public water systems located in Washington, D.C., and implements the regulations of the District of Columbia. EPA will send a compliance assurance notification to notify the District of Columbia of the enforcement action.