{"schema_version":"1.2","pwsid":"IL0312070","system_name":"NORTHBROOK","city":"NORTHBROOK","state":"IL","population_served":34200,"source_type":"SW","summary":"NORTHBROOK serves approximately 34,200 people in NORTHBROOK, Illinois. Based on contaminant analyses from DNR, WQP, 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 Lead (90th Percentile) at 0.011 mg/L, which is 55x the health guideline. Data is drawn from source-level compliance monitoring and covers 2000 through 2026. Results reflect conditions at the point of collection (wells, treatment plants), not necessarily at the tap.","data_period":{"start":"2000-05-10","end":"2026-09-25"},"contaminants_tested":42,"contaminants_detected":15,"exceedances":0,"guideline_exceedances":1,"contaminants":[{"name":"Total Trihalomethanes (TTHMs)","code":"2950","cas_number":null,"group":"dbps","section":"other_detected","measured_value":29.13,"unit":"ug/L","sample_date":"2026-09-08","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":"PFHpA (Perfluoroheptanoic 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