Document xzOnvdxqq9E9DN0rKJdqj1jN1

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 10 1200 Sixth Avenue, Suite 155 Seattle, WA 98101 WATER DIVISION June 5, 2023 The Honorable RoseMary LaClair Chairwoman of the Nooksack Indian Tribe 5016 Deming Road Deming, WA 98244 RE: Maximum Contaminant Level (MCL) Violation: Exceedance of 10 mg/L Nitrate Nooksack Indian Tribe 5 Cedars Community Water System, PWS #105300028 Dear Chairwoman LaClair: The purpose of this letter is to inform you of a nitrate MCL exceedance at 5 Cedars community water system, which constitutes a violation of the National Primary Drinking Water Regulations, 40 CFR 141.62(b). In accordance with 40 CFR 141.23(d), all public water systems are required to monitor drinking water to determine compliance with the MCL of 10 mg/L for nitrate. The level of a routine nitrate sample collected on 6/1/2023 by 5 Cedars was 22.8 mg/L. 5 Cedars was notified of the routine nitrate sample exceedance on 6/2/23, via email by the laboratory. Following notification of a routine nitrate sample exceeding the MCL, a Public Water System must collect a confirmation sample within 24 hours in accordance with 40 CFR 141.23(f)(2). The values of the initial and confirmation samples are averaged to determine compliance with the MCL. In this case, any value of the confirmation sample would cause the average to exceed the MCL. Therefore, the routine sample result of 22.8 mg/L was used to determine compliance, which exceeds the MCL of 10 mg/L for nitrate. In accordance with the Public Notification of Drinking Water Violation Rule 40 CFR 141.202(b) 5 Cedars must distribute Tier 1 Public Notification (PN) within 24 hours of notification of the nitrate MCL exceedance. 5 Cedars submitted to EPA on 6/2/23 a copy of the PN that was distributed and the completed Public Notification Certification Form. This requirement is complete. To return to compliance, 5 Cedars water system must demonstrate that finished water samples at the entry point to the distribution system are in compliance with the nitrate MCL. 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. Please contact R10TribalDW@epa.gov with questions. Sincerely, MICHAEL SZERLOG Digitally signed by MICHAEL SZERLOG Date: 2023.06.05 14:17:09 -07'00' Michael Szerlog, Acting Director Water Division cc: Mr. Joseph Bob Utility Manager, Nooksack Indian Tribe Ms. Sandy Redsteer Tribal Utility Consultant, Indian Health Service