{"schema_version":"1.2","pwsid":"IL0250200","system_name":"LOUISVILLE","city":"LOUISVILLE","state":"IL","population_served":1201,"source_type":"SW","summary":"LOUISVILLE serves approximately 1,201 people in LOUISVILLE, Illinois. Based on contaminant analyses from WQP, EPA ECHO, the most recent monitoring readings are within federal EPA standards (MCL), but this system has active MCL violations on record for 1 contaminant. 1 contaminant exceeds health-based guidelines. The most significant finding is Lead (90th Percentile) at 0.0019 mg/L, which is 9.5x the health guideline. Data is drawn from source-level compliance monitoring and covers 2000 through 2025. Results reflect conditions at the point of collection (wells, treatment plants), not necessarily at the tap.","data_period":{"start":"2000-10-24","end":"2025-12-31"},"contaminants_tested":1,"contaminants_detected":1,"exceedances":0,"guideline_exceedances":1,"contaminants":[{"name":"Nitrate (as N)","code":"NITRATE","cas_number":"14797-55-8","group":"inorganics","section":"other_detected","measured_value":21,"unit":"mg/L","sample_date":"2013-04-17","source":"WQP","source_scope":"regional_groundwater","health_guideline_value":10,"health_guideline_source":"EPA MCLG","epa_mcl_value":10,"status":"exceeds_legal_limit","detection_limit":null},{"name":"Lead (90th Percentile)","code":"PB90","cas_number":"7439-92-1","group":"lead_copper","section":"guideline_exceedance","measured_value":0.0019,"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}],"sources":[{"name":"WQP","url":"https://www.waterqualitydata.us/"},{"name":"EPA ECHO","url":"https://echo.epa.gov/"}],"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":[]}