{"schema_version":"1.2","pwsid":"IL0894070","system_name":"AURORA","city":"AURORA","state":"IL","population_served":183000,"source_type":"SW","summary":"AURORA serves approximately 183,000 people in AURORA, Illinois. Based on contaminant analyses from DNR, EPA ECHO, EPA UCMR5, 1 contaminant has been measured above federal EPA standards (MCL) and 2 exceed health-based guidelines. The most significant finding is Combined Radium (226+228) at 12.2 pCi/L, which is 2.4x the EPA legal limit. Data is drawn from source-level compliance monitoring and covers 2018 through 2026. Results reflect conditions at the point of collection (wells, treatment plants), not necessarily at the tap.","data_period":{"start":"2018-12-31","end":"2026-08-12"},"contaminants_tested":39,"contaminants_detected":14,"exceedances":1,"guideline_exceedances":2,"contaminants":[{"name":"Haloacetic Acids (HAA5)","code":"2456","cas_number":null,"group":"dbps","section":"other_detected","measured_value":19.8,"unit":"ug/L","sample_date":"2026-08-12","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":63.5,"unit":"ug/L","sample_date":"2026-08-12","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.00015,"health_guideline_source":"EWG Health 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(natural)","code":"FLUORIDE","cas_number":"16984-48-8","group":"inorganics","section":"other_detected","measured_value":0.58,"unit":"mg/L","sample_date":"2026-04-07","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":"Lead (90th Percentile)","code":"PB90","cas_number":"7439-92-1","group":"lead_copper","section":"guideline_exceedance","measured_value":0.024,"unit":"mg/L","sample_date":"2025-12-31","source":"EPA ECHO","source_scope":"federal_program","health_guideline_value":0.0002,"health_guideline_source":"OEHHA PHG","epa_mcl_value":null,"status":"exceeds_guideline","detection_limit":null},{"name":"Copper (90th 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UCMR5","source_scope":"federal_program","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":0.003},{"name":"Pfhxa","code":"PFHxA","cas_number":null,"group":"other","section":"pfas","measured_value":0.0035,"unit":"ug/L","sample_date":"2025-02-11","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":"PFBA (Perfluorobutanoic Acid)","code":"PFBA","cas_number":null,"group":"pfas","section":"pfas","measured_value":0.0055,"unit":"ug/L","sample_date":"2024-11-12","source":"EPA 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UCMR5","url":"https://www.epa.gov/dwucmr/fifth-unregulated-contaminant-monitoring-rule"}],"pfas_combined_display":null,"well_counts":{"active":20,"retired":3,"facilities_synced_at":"2026-09-06T14:49:36.593Z"},"historical_wells":[],"has_only_historical_data":false,"pfas_hazard_index":{"value":0.0019,"compounds_used":["PFBS"],"is_partial":true,"threshold":1,"components":[{"code":"PFBS","value_ng_l":3.7,"hbwc_ng_l":2000,"ratio":0.0019}]},"tthm_lraa":[{"monitoring_point":"Well S2HH2","value":63.5,"unit":"ug/L","quarters_used":["2025Q4","2026Q1","2026Q2","2026Q3"],"sample_count":4,"mcl":80,"exceeds_mcl":false},{"monitoring_point":"Well S2HT1","value":55.97,"unit":"ug/L","quarters_used":["2025Q4","2026Q1","2026Q2","2026Q3"],"sample_count":4,"mcl":80,"exceeds_mcl":false},{"monitoring_point":"Well S2HH3","value":54.3,"unit":"ug/L","quarters_used":["2025Q4","2026Q1","2026Q2","2026Q3"],"sample_count":4,"mcl":80,"exceeds_mcl":false},{"monitoring_point":"Well 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