{"schema_version":"1.2","pwsid":"IL1191000","system_name":"TROY","city":"TROY","state":"IL","population_served":16962,"source_type":"GW","summary":"TROY serves approximately 16,962 people in TROY, Illinois. Based on contaminant analyses from EPA ECHO, EPA UCMR5, 0 contaminants have been measured above federal EPA standards (MCL) and 1 exceeds health-based guidelines. The most significant finding is Copper (90th Percentile) at 1.69 mg/L, which is 5.6x the health guideline. Data is drawn from source-level compliance monitoring and covers 2017 through 2025. Results reflect conditions at the point of collection (wells, treatment plants), not necessarily at the tap.","data_period":{"start":"2017-12-31","end":"2025-12-31"},"contaminants_tested":32,"contaminants_detected":4,"exceedances":0,"guideline_exceedances":1,"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":"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":"below_limits","detection_limit":null},{"name":"Copper (90th Percentile)","code":"CU90","cas_number":"7440-50-8","group":"lead_copper","section":"guideline_exceedance","measured_value":1.69,"unit":"mg/L","sample_date":"2021-12-31","source":"EPA ECHO","source_scope":"federal_program","health_guideline_value":0.3,"health_guideline_source":"OEHHA PHG","epa_mcl_value":null,"status":"exceeds_guideline","detection_limit":null},{"name":"Lithium","code":"lithium","cas_number":null,"group":"other","section":"pfas","measured_value":10.9,"unit":"ug/L","sample_date":"2025-03-04","source":"EPA UCMR5","source_scope":"federal_program","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":9},{"name":"PFBS (Perfluorobutane Sulfonate)","code":"PFBS","cas_number":"375-73-5","group":"pfas","section":"pfas","measured_value":0.0039,"unit":"ug/L","sample_date":"2024-09-09","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":"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":4,"retired":1,"facilities_synced_at":"2026-09-06T14:49:36.593Z"},"historical_wells":[],"has_only_historical_data":false,"pfas_hazard_index":{"value":0.002,"compounds_used":["PFBS"],"is_partial":true,"threshold":1,"components":[{"code":"PFBS","value_ng_l":3.9,"hbwc_ng_l":2000,"ratio":0.002}]},"tthm_lraa":[],"haa5_lraa":[]}