The United States Environmental Protection Agency, Region 9 (EPA) and the Quechan Tribe of the Fort Yuma Indian Reservation California & Arizona (Quechan or Respondent) enter into this Administrative Order on Consent (Consent Order) for the purpose of bringing the Quechan Public Works and Utilities Public Water System, PWS ID. No. 09040089 (System), located within the external boundaries of the Fort Yuma Indian Reservation (Reservation), into compliance with the requirements of the Safe Drinking Water Act (SDWA), 42 U.S.C. 300(f) et seq., and the National Primary Drinking Water Regulations (NPDWRs) at 40 C.F.R. Part 141.