{"schema_version":"1.2","pwsid":"IL1194280","system_name":"COLLINSVILLE","city":"COLLINSVILLE","state":"IL","population_served":30616,"source_type":"GW","summary":"COLLINSVILLE serves approximately 30,616 people in COLLINSVILLE, Illinois. Based on contaminant analyses from DNR, WQP, EPA ECHO, EPA UCMR5, 3 contaminants have been measured above federal EPA standards (MCL) and 3 exceed health-based guidelines. The most significant finding is PFOA (Perfluorooctanoic Acid) at 0.018 ug/L, which is 4.5x the EPA legal limit. Data is drawn from source-level compliance monitoring and covers 2000 through 2028. Results reflect conditions at the point of collection (wells, treatment plants), not necessarily at the tap.","data_period":{"start":"2000-11-03","end":"2028-12-31"},"contaminants_tested":36,"contaminants_detected":14,"exceedances":3,"guideline_exceedances":3,"contaminants":[{"name":"Nitrate (as N)","code":"NITRATE","cas_number":"14797-55-8","group":"inorganics","section":"other_detected","measured_value":8.58,"unit":"mg/L","sample_date":"2026-10-05","source":"DNR","source_scope":"source_monitoring","health_guideline_value":10,"health_guideline_source":"EPA MCLG","epa_mcl_value":10,"status":"approaching","detection_limit":null},{"name":"Methyl Tert Butyl Ether","code":"METHYL_TERT_BUTYL_ETHER","cas_number":null,"group":"other","section":"other_detected","measured_value":0.54,"unit":"ug/L","sample_date":"2026-03-16","source":"DNR","source_scope":"source_monitoring","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":null},{"name":"Haloacetic Acids (HAA5)","code":"2456","cas_number":null,"group":"dbps","section":"other_detected","measured_value":5.2,"unit":"ug/L","sample_date":"2025-10-29","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":30.4,"unit":"ug/L","sample_date":"2025-10-29","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":"Fluoride (natural)","code":"FLUORIDE","cas_number":"16984-48-8","group":"inorganics","section":"other_detected","measured_value":0.17,"unit":"mg/L","sample_date":"2023-08-23","source":"WQP","source_scope":"regional_groundwater","health_guideline_value":4,"health_guideline_source":"EPA MCLG","epa_mcl_value":4,"status":"below_limits","detection_limit":null},{"name":"Arsenic","code":"ARSENIC","cas_number":"7440-38-2","group":"inorganics","section":"other_detected","measured_value":1.7,"unit":"ug/L","sample_date":"2023-08-23","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":"Barium","code":"BARIUM","cas_number":"7440-39-3","group":"inorganics","section":"other_detected","measured_value":0.214,"unit":"mg/L","sample_date":"2023-08-23","source":"WQP","source_scope":"regional_groundwater","health_guideline_value":1,"health_guideline_source":"OEHHA PHG 2003 (hypertension endpoint)","epa_mcl_value":2,"status":"below_limits","detection_limit":null},{"name":"Chromium (total)","code":"CHROMIUM","cas_number":"7440-47-3","group":"inorganics","section":"other_detected","measured_value":1.1,"unit":"ug/L","sample_date":"2015-08-04","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":"Lead (90th Percentile)","code":"PB90","cas_number":"7439-92-1","group":"lead_copper","section":"other_detected","measured_value":0,"unit":"mg/L","sample_date":"2028-12-31","source":"EPA ECHO","source_scope":"federal_program","health_guideline_value":0.0002,"health_guideline_source":"OEHHA PHG","epa_mcl_value":null,"status":"below_limits","detection_limit":null},{"name":"Copper (90th Percentile)","code":"COPPER","cas_number":"7440-50-8","group":"lead_copper","section":"other_detected","measured_value":31.6,"unit":"ug/L","sample_date":"2026-06-17","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.3,"health_guideline_source":"OEHHA PHG","epa_mcl_value":null,"status":"below_limits","detection_limit":null},{"name":"PFBA (Perfluorobutanoic Acid)","code":"PFBA","cas_number":null,"group":"pfas","section":"pfas","measured_value":0.013,"unit":"ug/L","sample_date":"2024-08-01","source":"EPA UCMR5","source_scope":"federal_program","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":0.005},{"name":"Pfhxa","code":"PFHxA","cas_number":null,"group":"other","section":"pfas","measured_value":0.022,"unit":"ug/L","sample_date":"2024-08-01","source":"EPA UCMR5","source_scope":"federal_program","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":0.003},{"name":"Pfpea","code":"PFPeA","cas_number":null,"group":"other","section":"pfas","measured_value":0.021,"unit":"ug/L","sample_date":"2024-08-01","source":"EPA UCMR5","source_scope":"federal_program","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":0.003},{"name":"PFOA (Perfluorooctanoic Acid)","code":"PFOA","cas_number":"335-67-1","group":"pfas","section":"legal_violation","measured_value":0.018,"unit":"ug/L","sample_date":"2024-08-01","source":"EPA 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":"legal_violation","measured_value":0.0089,"unit":"ug/L","sample_date":"2024-08-01","source":"EPA 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":"PFHxS (Perfluorohexane Sulfonate)","code":"PFHXS","cas_number":"355-46-4","group":"pfas","section":"legal_violation","measured_value":0.012,"unit":"ug/L","sample_date":"2024-08-01","source":"EPA UCMR5","source_scope":"federal_program","health_guideline_value":0.01,"health_guideline_source":"EPA MCLG","epa_mcl_value":0.01,"status":"exceeds_legal_limit","detection_limit":0.003},{"name":"PFBS (Perfluorobutane Sulfonate)","code":"PFBS","cas_number":"375-73-5","group":"pfas","section":"pfas","measured_value":0.016,"unit":"ug/L","sample_date":"2024-08-01","source":"EPA UCMR5","source_scope":"federal_program","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":0.003},{"name":"Pfhpa","code":"PFHpA","cas_number":null,"group":"other","section":"pfas","measured_value":0.013,"unit":"ug/L","sample_date":"2024-08-01","source":"EPA UCMR5","source_scope":"federal_program","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":0.003}],"sources":[{"name":"DNR","url":"https://apps.dnr.wi.gov/dwsportalpub"},{"name":"WQP","url":"https://www.waterqualitydata.us/"},{"name":"EPA ECHO","url":"https://echo.epa.gov/"},{"name":"EPA UCMR5","url":"https://www.epa.gov/dwucmr/fifth-unregulated-contaminant-monitoring-rule"}],"pfas_combined_display":null,"well_counts":{"active":6,"retired":3,"facilities_synced_at":"2026-10-26T01:13:06.376Z"},"historical_wells":[],"has_only_historical_data":false,"pfas_hazard_index":{"value":1.208,"compounds_used":["PFHXS","PFBS"],"is_partial":true,"threshold":1,"components":[{"code":"PFHXS","value_ng_l":12,"hbwc_ng_l":10,"ratio":1.2},{"code":"PFBS","value_ng_l":16,"hbwc_ng_l":2000,"ratio":0.008}]},"tthm_lraa":[],"haa5_lraa":[]}