Document DMkR7yOo12xBmbV9nGYj4vGqM

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 10 1200 Sixth Avenue, Suite 155 Seattle, WA 98101 WATER DIVISION David Lucas Public Works Manager Makah Tribe P.O. Box 115 Neah Bay, WA 98357 July 13, 2023 Re: Total Trihalomethane (TTHM) Maximum Contaminant Level (MCL) Violation Makah, PWS ID 105300012 Dear Mr. Lucas: The Makah public water system recently violated the total trihalomethane (TTHM) maximum contaminant level (MCL) of 0.080 mg/L or 80 g/L, according to 40 CFR 141.64(b). Compliance with the TTHM MCL is determined every quarter by calculating a running annual average of TTHM monitoring results at site S-10 ((b) (6) from the four most recent quarters, as specified in 40 CFR 141.620. The results of the last four quarters of samples and the average of these results are: Date 4/11/2022 10/3/2022 1/25/2023 6/12/2023 Average Result (g/L) 59.0 194.7 65.0 60.0 94.7 Your system's current running annual average for TTHMs is 94.7 g/L, which constitutes a violation of the National Primary Drinking Water Regulations. A public water system that violates an MCL is required to notify the public of this MCL violation as soon as practical, but no later than 30 days after learning of the violation. This public notice (PN) must be delivered by hand or mail and made available to all persons served by the water system, for example via newspaper, email or by posting in a public location. Please see the enclosed PN template and instructions. You must also send a copy of the PN along with a certification form (enclosed) to the EPA no later than ten days after you notify your customers. This letter serves as initial notification of non-compliance under the Safe Drinking Water Act for the regulation and time period cited. EPA supports compliance assistance and encourages early action to return to compliance. Issues not addressed in a timely manner may be referred to enforcement. Prior to an enforcement action for the cited violation(s), EPA Region 10 will offer government-to-government consultation, in accordance with the EPA Policy on Consultation and Coordination with Indian Tribes.