{"schema_version":"1.2","pwsid":"IL0970840","system_name":"LAKE VILLA","city":null,"state":"IL","population_served":8829,"source_type":"SW","summary":"LAKE VILLA serves approximately 8,829 people in an unincorporated area, 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 8.55 pCi/L, which is 1.7x the EPA legal limit. Data is drawn from source-level compliance monitoring and covers 2016 through 2028. Results reflect conditions at the point of collection (wells, treatment plants), not necessarily at the tap.","data_period":{"start":"2016-12-31","end":"2028-12-31"},"contaminants_tested":39,"contaminants_detected":9,"exceedances":1,"guideline_exceedances":2,"contaminants":[{"name":"Arsenic","code":"ARSENIC","cas_number":"7440-38-2","group":"inorganics","section":"guideline_exceedance","measured_value":0.0011,"unit":"mg/L","sample_date":"2026-08-12","source":"DNR","source_scope":"source_monitoring","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":0.066,"unit":"mg/L","sample_date":"2026-08-12","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":1.27,"unit":"mg/L","sample_date":"2026-08-12","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":"Combined Radium (226+228)","code":"4010","cas_number":null,"group":"radionuclides","section":"legal_violation","measured_value":8.55,"unit":"pCi/L","sample_date":"2026-08-12","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0,"health_guideline_source":"EPA MCLG","epa_mcl_value":5,"status":"exceeds_legal_limit","detection_limit":null},{"name":"Gross Alpha","code":"4000","cas_number":null,"group":"radionuclides","section":"other_detected","measured_value":12.6,"unit":"pCi/L","sample_date":"2026-08-12","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0,"health_guideline_source":"EPA MCLG","epa_mcl_value":15,"status":"approaching","detection_limit":null},{"name":"Haloacetic Acids (HAA5)","code":"2456","cas_number":null,"group":"dbps","section":"other_detected","measured_value":10,"unit":"ug/L","sample_date":"2026-08-04","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":25.63,"unit":"ug/L","sample_date":"2026-08-04","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":"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":190,"unit":"ug/L","sample_date":"2026-06-30","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}],"sources":[{"name":"DNR","url":"https://apps.dnr.wi.gov/dwsportalpub"},{"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":9,"retired":6,"facilities_synced_at":"2026-10-26T01:13:06.376Z"},"historical_wells":[],"has_only_historical_data":false,"pfas_hazard_index":null,"tthm_lraa":[{"monitoring_point":"Well S2HH2","value":25.63,"unit":"ug/L","quarters_used":["2025Q4","2026Q1","2026Q2","2026Q3"],"sample_count":4,"mcl":80,"exceeds_mcl":false},{"monitoring_point":"Well S2HT1","value":24.61,"unit":"ug/L","quarters_used":["2025Q4","2026Q1","2026Q2","2026Q3"],"sample_count":4,"mcl":80,"exceeds_mcl":false}],"haa5_lraa":[{"monitoring_point":"Well S2HT1","value":10,"unit":"ug/L","quarters_used":["2025Q4","2026Q1","2026Q2","2026Q3"],"sample_count":4,"mcl":60,"exceeds_mcl":false},{"monitoring_point":"Well S2HH2","value":8.73,"unit":"ug/L","quarters_used":["2025Q4","2026Q1","2026Q2","2026Q3"],"sample_count":4,"mcl":60,"exceeds_mcl":false}]}