The United States Environmental Protection Agency, Region 9 (EPA) is issuing this Unilateral Administrative Order ( Order ) for the purpose of bringing the Havasu Water Company public water system, PWS ID. No. 090600202 ( System ), which is located within the external boundaries of the Chemehuevi Indian Reservation, into compliance with the requirements of the Safe Drinking Water Act (SDWA), 42 U.S.C. 300f et seq., and the National Primary Drinking Water Regulations (NPDWRs) at 40 C.F.R. Part 141.