{"schema_version":"1.2","pwsid":"IL1971100","system_name":"WILMINGTON","city":"WILMINGTON","state":"IL","population_served":5700,"source_type":"SW","summary":"WILMINGTON serves approximately 5,700 people in WILMINGTON, Illinois. Based on contaminant analyses from DNR, WQP, EPA ECHO, EPA UCMR5, 0 contaminants have been measured above federal EPA standards (MCL) and 2 exceed health-based guidelines. The most significant finding is Lead (90th Percentile) at 0.00499 mg/L, which is 24.9x the health guideline. Data is drawn from source-level compliance monitoring and covers 1999 through 2026. Results reflect conditions at the point of collection (wells, treatment plants), not necessarily at the tap.","data_period":{"start":"1999-07-13","end":"2026-09-25"},"contaminants_tested":41,"contaminants_detected":15,"exceedances":0,"guideline_exceedances":2,"contaminants":[{"name":"Gross Alpha","code":"4000","cas_number":null,"group":"radionuclides","section":"other_detected","measured_value":2.08,"unit":"pCi/L","sample_date":"2026-09-24","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0,"health_guideline_source":"EPA MCLG","epa_mcl_value":15,"status":"below_limits","detection_limit":null},{"name":"Haloacetic Acids (HAA5)","code":"2456","cas_number":null,"group":"dbps","section":"other_detected","measured_value":37.44,"unit":"ug/L","sample_date":"2026-08-10","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":"Nitrate (as N)","code":"NITRATE","cas_number":"14797-55-8","group":"inorganics","section":"other_detected","measured_value":1.39,"unit":"mg/L","sample_date":"2026-07-20","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":"Atrazine","code":"2050","cas_number":null,"group":"vocs","section":"guideline_exceedance","measured_value":1.39,"unit":"ug/L","sample_date":"2026-06-18","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.00015,"health_guideline_source":"OEHHA PHG 1999","epa_mcl_value":0.003,"status":"exceeds_guideline","detection_limit":null},{"name":"Total Trihalomethanes (TTHMs)","code":"2950","cas_number":null,"group":"dbps","section":"other_detected","measured_value":65,"unit":"ug/L","sample_date":"2026-05-11","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.00015,"health_guideline_source":"EWG Health Guideline","epa_mcl_value":0.08,"status":"approaching","detection_limit":null},{"name":"Tritium","code":"TRITIUM","cas_number":null,"group":"radionuclides","section":"other_detected","measured_value":3582,"unit":"pCi/L","sample_date":"2026-01-07","source":"DNR","source_scope":"source_monitoring","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":20000,"status":"below_limits","detection_limit":null},{"name":"Barium","code":"BARIUM","cas_number":"7440-39-3","group":"inorganics","section":"other_detected","measured_value":0.0081,"unit":"mg/L","sample_date":"2025-11-12","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":"Fluoride (natural)","code":"FLUORIDE","cas_number":"16984-48-8","group":"inorganics","section":"other_detected","measured_value":0.557,"unit":"mg/L","sample_date":"2025-11-12","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":"Arsenic","code":"ARSENIC","cas_number":"7440-38-2","group":"inorganics","section":"other_detected","measured_value":0.56,"unit":"ug/L","sample_date":"2023-08-21","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":"Chromium (total)","code":"CHROMIUM","cas_number":"7440-47-3","group":"inorganics","section":"other_detected","measured_value":0.38,"unit":"ug/L","sample_date":"2012-07-30","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":"Toc","code":"TOC","cas_number":null,"group":"other","section":"other_detected","measured_value":6.48,"unit":"mg/L","sample_date":"2026-09-22","source":"DNR","source_scope":"source_monitoring","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":null},{"name":"Lead (90th Percentile)","code":"PB90","cas_number":"7439-92-1","group":"lead_copper","section":"guideline_exceedance","measured_value":0.00499,"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 Percentile)","code":"COPPER","cas_number":"7440-50-8","group":"lead_copper","section":"other_detected","measured_value":82.9,"unit":"ug/L","sample_date":"2026-09-25","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":"Pfpea","code":"PFPeA","cas_number":null,"group":"other","section":"pfas","measured_value":0.0045,"unit":"ug/L","sample_date":"2025-09-09","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":"PFBS (Perfluorobutane Sulfonate)","code":"PFBS","cas_number":"375-73-5","group":"pfas","section":"pfas","measured_value":0.0031,"unit":"ug/L","sample_date":"2025-09-09","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":0.0057,"unit":"ug/L","sample_date":"2025-09-09","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":0.004,"unit":"ug/L","sample_date":"2025-09-09","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":1,"retired":2,"facilities_synced_at":"2026-10-26T01:13:06.376Z"},"historical_wells":[],"has_only_historical_data":false,"pfas_hazard_index":{"value":0.0016,"compounds_used":["PFBS"],"is_partial":true,"threshold":1,"components":[{"code":"PFBS","value_ng_l":3.1,"hbwc_ng_l":2000,"ratio":0.0016}]},"tthm_lraa":[],"haa5_lraa":[{"monitoring_point":"Well S2HH1","value":37.44,"unit":"ug/L","quarters_used":["2025Q4","2026Q1","2026Q2","2026Q3"],"sample_count":5,"mcl":60,"exceeds_mcl":false},{"monitoring_point":"Well S2HT1","value":31.54,"unit":"ug/L","quarters_used":["2025Q4","2026Q1","2026Q2","2026Q3"],"sample_count":4,"mcl":60,"exceeds_mcl":false}]}