{"schema_version":"1.2","pwsid":"IL0971250","system_name":"NORTH CHICAGO","city":"NORTH CHICAGO","state":"IL","population_served":16813,"source_type":"SW","summary":"NORTH CHICAGO serves approximately 16,813 people in NORTH CHICAGO, Illinois. Based on contaminant analyses from EPA ECHO, EPA UCMR5, the most recent monitoring readings are within federal EPA standards (MCL), but this system has active MCL violations on record for 2 contaminants. 0 contaminants exceed health-based guidelines. Data is drawn from source-level compliance monitoring and covers 2017 through 2026. Results reflect conditions at the point of collection (wells, treatment plants), not necessarily at the tap.","data_period":{"start":"2017-12-31","end":"2026-06-30"},"contaminants_tested":31,"contaminants_detected":1,"exceedances":0,"guideline_exceedances":0,"contaminants":[{"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":"2026-06-30","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}],"sources":[{"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":0,"retired":0,"facilities_synced_at":"2026-09-06T14:49:36.593Z"},"historical_wells":[],"has_only_historical_data":false,"pfas_hazard_index":null,"tthm_lraa":[],"haa5_lraa":[]}