US EPA issued an Administrative Order for Compliance to First Mesa Consolidated Villages (FMCV) for violations of the federal Safe Drinking Water Act (SDWA) at the Polacca public water system (the System), which FMCV owns and/or operates on the Hopi Indian Reservation. EPA has determined that the System is out of compliance with the maximum contaminant level for arsenic, the monitoring requirements for arsenic, and the Tier 2 public notice requirements. This Order requires, among other things, that FMCV submit within 15 days of the effective date of this Order a letter describing its intention to comply with this Order, meet the arsenic MCL by December 31, 2023 and submit a compliance plan within 90 days of the effective date of the Order that specifies how FMCV will bring the System back into compliance with the SDWA, including identifying enforceable milestones.