{"schema_version":"1.2","pwsid":"WI2670110","system_name":"HARTFORD WATERWORKS","city":"HARTFORD","state":"WI","population_served":15805,"source_type":"GW","summary":"HARTFORD WATERWORKS serves approximately 15,805 people in HARTFORD, Wisconsin. Based on contaminant analyses from DNR, WQP, EPA ECHO, EPA UCMR5, 1 contaminant has been measured above federal EPA standards (MCL) and 4 exceed health-based guidelines. The most significant finding is PFOA (Perfluorooctanoic Acid) at 0.0062 ug/L, which is 1.5x the EPA legal limit. Data is drawn from source-level compliance monitoring and covers 2000 through 2026. Results reflect conditions at the point of collection (wells, treatment plants), not necessarily at the tap.","data_period":{"start":"2000-04-11","end":"2026-03-10"},"contaminants_tested":97,"contaminants_detected":20,"exceedances":1,"guideline_exceedances":4,"contaminants":[{"name":"Chlorine (free)","code":"0700","cas_number":null,"group":"disinfectants","section":"other_detected","measured_value":0.65,"unit":"mg/L","sample_date":"2026-03-10","source":"DNR","source_scope":"source_monitoring","health_guideline_value":4,"health_guideline_source":"EPA MCLG","epa_mcl_value":4,"status":"below_limits","detection_limit":null},{"name":"Chlorine (total residual)","code":"0700_TOTAL","cas_number":null,"group":"disinfectants","section":"other_detected","measured_value":0.67,"unit":"mg/L","sample_date":"2026-03-10","source":"DNR","source_scope":"source_monitoring","health_guideline_value":4,"health_guideline_source":"EPA 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(total)","code":"CHROMIUM","cas_number":"7440-47-3","group":"inorganics","section":"other_detected","measured_value":2.2,"unit":"ug/L","sample_date":"2021-05-18","source":"WQP","source_scope":"regional_groundwater","health_guideline_value":0.1,"health_guideline_source":"EPA MCLG","epa_mcl_value":0.1,"status":"below_limits","detection_limit":null},{"name":"Toluene","code":"2964","cas_number":null,"group":"other","section":"other_detected","measured_value":0.47,"unit":"ug/L","sample_date":"2023-07-11","source":"DNR","source_scope":"source_monitoring","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":null},{"name":"Arsenic","code":"ARSENIC","cas_number":"7440-38-2","group":"inorganics","section":"other_detected","measured_value":0.15,"unit":"ug/L","sample_date":"2013-08-12","source":"WQP","source_scope":"regional_groundwater","health_guideline_value":0.000004,"health_guideline_source":"OEHHA PHG","epa_mcl_value":0.01,"status":"exceeds_guideline","detection_limit":null},{"name":"Nickel","code":"1036","cas_number":null,"group":"inorganics","section":"other_detected","measured_value":0.0026,"unit":"mg/L","sample_date":"2026-02-09","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.012,"health_guideline_source":"OEHHA PHG","epa_mcl_value":null,"status":"below_limits","detection_limit":null},{"name":"Barium","code":"BARIUM","cas_number":"7440-39-3","group":"inorganics","section":"other_detected","measured_value":0.068,"unit":"mg/L","sample_date":"2026-02-09","source":"DNR","source_scope":"source_monitoring","health_guideline_value":1,"health_guideline_source":"OEHHA PHG 2003 (hypertension endpoint)","epa_mcl_value":2,"status":"below_limits","detection_limit":null},{"name":"Nitrate (as N)","code":"NITRATE","cas_number":"14797-55-8","group":"inorganics","section":"other_detected","measured_value":3.7,"unit":"mg/L","sample_date":"2026-02-09","source":"DNR","source_scope":"source_monitoring","health_guideline_value":10,"health_guideline_source":"EPA MCLG","epa_mcl_value":10,"status":"below_limits","detection_limit":null},{"name":"Combined Radium (226+228)","code":"4010","cas_number":null,"group":"radionuclides","section":"other_detected","measured_value":1.279,"unit":"pCi/L","sample_date":"2026-02-09","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0,"health_guideline_source":"EPA MCLG","epa_mcl_value":5,"status":"below_limits","detection_limit":null},{"name":"Uranium","code":"4006","cas_number":"7440-61-1","group":"radionuclides","section":"guideline_exceedance","measured_value":3.67,"unit":"ug/L","sample_date":"2026-02-09","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.0005,"health_guideline_source":"OEHHA PHG","epa_mcl_value":0.03,"status":"exceeds_guideline","detection_limit":null},{"name":"Haloacetic Acids (HAA5)","code":"2456","cas_number":null,"group":"dbps","section":"other_detected","measured_value":2.26,"unit":"ug/L","sample_date":"2025-07-14","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.0001,"health_guideline_source":"EWG Health Guideline","epa_mcl_value":0.06,"status":"below_limits","detection_limit":null},{"name":"Total Trihalomethanes (TTHMs)","code":"2950","cas_number":null,"group":"dbps","section":"other_detected","measured_value":4.29,"unit":"ug/L","sample_date":"2025-07-14","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.00015,"health_guideline_source":"EWG Health Guideline","epa_mcl_value":0.08,"status":"below_limits","detection_limit":null},{"name":"PFHpA (Perfluoroheptanoic 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UCMR5","source_scope":"federal_program","health_guideline_value":0,"health_guideline_source":"EPA MCLG","epa_mcl_value":0.004,"status":"exceeds_legal_limit","detection_limit":0.004},{"name":"PFOS (Perfluorooctane Sulfonate)","code":"PFOS","cas_number":"1763-23-1","group":"pfas","section":"pfas","measured_value":3.9,"unit":"ng/L","sample_date":"2025-01-29","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0,"health_guideline_source":"EPA MCLG","epa_mcl_value":0.004,"status":"approaching","detection_limit":null},{"name":"PFHxS (Perfluorohexane Sulfonate)","code":"PFHXS","cas_number":"355-46-4","group":"pfas","section":"pfas","measured_value":4.4,"unit":"ng/L","sample_date":"2025-01-29","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.01,"health_guideline_source":"EPA MCLG","epa_mcl_value":0.01,"status":"below_limits","detection_limit":null},{"name":"PFHxA (Perfluorohexanoic 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Not a current MCL."},"well_counts":{"active":4,"retired":7,"facilities_synced_at":"2026-04-11T13:48:07.246Z"},"historical_wells":[{"state_facility_id":"16","facility_name":"WJ889","deactivation_date":"2026-02-24","top_contaminant":"PFOA (Perfluorooctanoic Acid)","top_contaminant_code":"PFOA","max_value":5.8,"unit":"ng/L","classification":"above_mcl","mcl_or_phg_value":4,"mcl_or_phg_unit":"ng/L","validated_reason":null}],"has_only_historical_data":false,"pfas_hazard_index":{"value":0.4404,"compounds_used":["PFHXS","PFBS"],"is_partial":true,"threshold":1,"components":[{"code":"PFHXS","value_ng_l":4.4,"hbwc_ng_l":10,"ratio":0.44},{"code":"PFBS","value_ng_l":0.88,"hbwc_ng_l":2000,"ratio":0.0004}]},"tthm_lraa":[{"monitoring_point":"system_wide","value":4.29,"unit":"ug/L","quarters_used":["2021Q3","2023Q3","2024Q3","2025Q3"],"sample_count":8,"mcl":80,"exceeds_mcl":false}],"haa5_lraa":[{"monitoring_point":"system_wide","value":2.26,"unit":"ug/L","quarters_used":["2021Q3","2023Q3","2024Q3","2025Q3"],"sample_count":8,"mcl":60,"exceeds_mcl":false}]}