{"schemaVersion":2,"id":"us-MA4310003","communeId":"MA4310003","name":"Onset Fire Districtwater Dept.","slug":"onset-fire-districtwater-dept-ma4310003","country":"us","region":"Massachusetts","supplier":"ONSET FIRE DISTRICT","networks":[{"code":"431000301G/10400","name":"WELLS #3,#4 (01G,02G) (WELL # 4)"},{"code":"431000303G/10401","name":"WELL #5 (WELL # 5)"},{"code":"431000304G/10402","name":"WELL #6 (WELL 6)"},{"code":"431000305G/10405","name":"WELL #7 (WELL # 7)"}],"latestSampleDate":"2025-12-02T00:00:00Z","conformity":{"conclusion":null,"bacteriological":"unknown","chemical":"unknown"},"source":{"name":"U.S. Environmental Protection Agency, Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) occurrence data, final dataset (August 2026)","url":"https://www.epa.gov/dwucmr/occurrence-data-unregulated-contaminant-monitoring-rule","license":"Public domain (U.S. federal government work, 17 U.S.C. § 105)","kind":"open_data_file","verified":true,"retrievedAt":"2026-09-19T19:22:35.464Z","note":"UCMR 5 results do not indicate compliance or noncompliance with the PFAS drinking water standards. Samples are taken at the entry point to the distribution system, not at the tap; the system may have changed sources or installed treatment since. Treatment reported to EPA for PFAS: no PFAS treatment (NMT). 4 entry points sampled, 8 sampling events between 2025-06-24 and 2025-12-02. The page's PFAS values come from the newest sample at WELLS #3,#4 (01G,02G) (WELL # 4) (431000301G/10400), the entry point with the highest PFOA + PFOS + PFNA + PFHxS sum; the other entry points' maxima are listed as separate rows. Non-detects are shown as \"<\" followed by EPA's minimum reporting level (3 to 20 ng/L); PFAS-4 sums quantified compounds only, so it is a lower bound when a compound was not detected. Registry (name, population, counties, ZIPs) from EPA SDWIS/ECHO; service-area centroid from EPA ORD."},"pfas":{"status":"measured","sum20":null,"pfas4":{"value":0.0052,"valueText":"0.0052","unit":"µg/L","limit":0.004,"limitUnit":"µg/L","status":"exceeded","sampleDate":"2025-12-02T00:00:00Z","sampleId":"135020P"},"pfas4DetectedCount":1,"lowerBound":true,"sampledAt":{"commune":"MA4310003","name":"WELLS #3,#4 (01G,02G) (WELL # 4)","network":"431000301G/10400"},"qualifiers":[{"name":"PFOA","valueText":"<0.004","unit":"µg/L"},{"name":"PFHxS","valueText":"<0.003","unit":"µg/L"},{"name":"PFNA","valueText":"<0.004","unit":"µg/L"},{"name":"HFPO-DA","valueText":"<0.005","unit":"µg/L"},{"name":"PFBS","valueText":"<0.003","unit":"µg/L"},{"name":"11Cl-PF3OUdS","valueText":"<0.005","unit":"µg/L"},{"name":"4:2 FTS","valueText":"<0.003","unit":"µg/L"},{"name":"6:2 FTS","valueText":"<0.005","unit":"µg/L"},{"name":"8:2 FTS","valueText":"<0.005","unit":"µg/L"},{"name":"9Cl-PF3ONS","valueText":"<0.002","unit":"µg/L"},{"name":"ADONA","valueText":"<0.003","unit":"µg/L"},{"name":"NEtFOSAA","valueText":"<0.005","unit":"µg/L"},{"name":"NFDHA","valueText":"<0.02","unit":"µg/L"},{"name":"NMeFOSAA","valueText":"<0.006","unit":"µg/L"},{"name":"PFBA","valueText":"<0.005","unit":"µg/L"},{"name":"PFDA","valueText":"<0.003","unit":"µg/L"},{"name":"PFDoA","valueText":"<0.003","unit":"µg/L"},{"name":"PFEESA","valueText":"<0.003","unit":"µg/L"},{"name":"PFHpA","valueText":"<0.003","unit":"µg/L"},{"name":"PFHpS","valueText":"<0.003","unit":"µg/L"},{"name":"PFHxA","valueText":"<0.003","unit":"µg/L"},{"name":"PFMBA","valueText":"<0.003","unit":"µg/L"},{"name":"PFMPA","valueText":"<0.004","unit":"µg/L"},{"name":"PFPeA","valueText":"<0.003","unit":"µg/L"},{"name":"PFPeS","valueText":"<0.004","unit":"µg/L"},{"name":"PFTA","valueText":"<0.008","unit":"µg/L"},{"name":"PFTrDA","valueText":"<0.007","unit":"µg/L"},{"name":"PFUnA","valueText":"<0.002","unit":"µg/L"}],"comparison":{"proposed":{"value":0.0005,"period":"annual_mean","official":false,"state":"over"},"sweden":{"value":0.004,"jurisdiction":"se"},"franceSum20":{"value":0.1,"jurisdiction":"fr"}}},"samples":[{"id":"135020P","date":"2025-12-02","commune":"MA4310003","communeName":"ONSET FIRE DISTRICT","sourceUrl":"https://www.epa.gov/dwucmr/occurrence-data-unregulated-contaminant-monitoring-rule","networks":["431000301G/10400"],"sum20":null,"pfas4":{"value":0.0052,"valueText":"0.0052","unit":"µg/L","nonDetect":false,"lowerBound":true,"qualifiers":[{"name":"PFOA","valueText":"<0.004","unit":"µg/L"},{"name":"PFHxS","valueText":"<0.003","unit":"µg/L"},{"name":"PFNA","valueText":"<0.004","unit":"µg/L"}]},"revision":"5f86924bbcc8730ddf8ff53603dc0315f2b84851072d4d80da8320856bf7ba5a"},{"id":"135021P","date":"2025-12-02","commune":"MA4310003","communeName":"ONSET FIRE 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