{"schema_version":"1.2","pwsid":"IL0790010","system_name":"EJ WATER COOPERATIVE","city":"DIETERICH","state":"IL","population_served":29720,"source_type":"SW","summary":"EJ WATER COOPERATIVE serves approximately 29,720 people in DIETERICH, Illinois. Based on contaminant analyses from DNR, WQP, 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 1 contaminant. 3 contaminants exceed health-based guidelines. The most significant finding is Lead (90th Percentile) at 0.002 mg/L, which is 10x 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":"2000-10-23","end":"2026-12-31"},"contaminants_tested":45,"contaminants_detected":20,"exceedances":0,"guideline_exceedances":3,"contaminants":[{"name":"Nitrate (as N)","code":"NITRATE","cas_number":"14797-55-8","group":"inorganics","section":"other_detected","measured_value":1.3,"unit":"mg/L","sample_date":"2026-10-12","source":"DNR","source_scope":"source_monitoring","health_guideline_value":10,"health_guideline_source":"EPA MCLG","epa_mcl_value":10,"status":"below_limits","detection_limit":null},{"name":"Haloacetic Acids (HAA5)","code":"2456","cas_number":null,"group":"dbps","section":"other_detected","measured_value":17.7,"unit":"ug/L","sample_date":"2026-08-19","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.0001,"health_guideline_source":"EWG Health 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