{"schema_version":"1.2","pwsid":"MN1820020","system_name":"Oak Park Heights","city":"Oak Park Heights","state":"MN","population_served":4776,"source_type":"GW","summary":"Oak Park Heights serves approximately 4,776 people in Oak Park Heights, Minnesota. 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 Tetrachloroethylene (PCE) at 0.1 ug/L, which is 1.7x the health guideline. Data is drawn from source-level compliance monitoring and covers 1996 through 2026. Results reflect conditions at the point of collection (wells, treatment plants), not necessarily at the tap.","data_period":{"start":"1996-03-15","end":"2026-09-05"},"contaminants_tested":39,"contaminants_detected":15,"exceedances":0,"guideline_exceedances":1,"contaminants":[{"name":"PFPeA (Perfluoropentanoic Acid)","code":"PFPEA","cas_number":null,"group":"pfas","section":"other_detected","measured_value":4.6,"unit":"ng/L","sample_date":"2026-09-05","source":"DNR","source_scope":"source_monitoring","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":null},{"name":"PFPeS (Perfluoropentane Sulfonate)","code":"PFPES","cas_number":null,"group":"pfas","section":"other_detected","measured_value":2.5,"unit":"ng/L","sample_date":"2026-09-05","source":"DNR","source_scope":"source_monitoring","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":null},{"name":"Haloacetic Acids (HAA5)","code":"2456","cas_number":null,"group":"dbps","section":"other_detected","measured_value":1.53,"unit":"ug/L","sample_date":"2025-12-31","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.0001,"health_guideline_source":"EWG Health Guideline","epa_mcl_value":0.06,"status":"below_limits","detection_limit":null},{"name":"Nitrate (as N)","code":"NITRATE","cas_number":"14797-55-8","group":"inorganics","section":"other_detected","measured_value":3.2,"unit":"mg/L","sample_date":"2025-12-31","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":"Tetrachloroethylene (PCE)","code":"2987","cas_number":null,"group":"vocs","section":"guideline_exceedance","measured_value":0.1,"unit":"ug/L","sample_date":"2025-12-31","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.00006,"health_guideline_source":"OEHHA PHG","epa_mcl_value":0.005,"status":"exceeds_guideline","detection_limit":null},{"name":"Trichloroethylene (TCE)","code":"2984","cas_number":null,"group":"vocs","section":"other_detected","measured_value":0.05,"unit":"ug/L","sample_date":"2025-12-31","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.0017,"health_guideline_source":"OEHHA PHG","epa_mcl_value":0.005,"status":"below_limits","detection_limit":null},{"name":"Total Trihalomethanes (TTHMs)","code":"2950","cas_number":null,"group":"dbps","section":"other_detected","measured_value":8.78,"unit":"ug/L","sample_date":"2025-12-31","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":"Barium","code":"BARIUM","cas_number":"7440-39-3","group":"inorganics","section":"other_detected","measured_value":0.443,"unit":"mg/L","sample_date":"2025-09-22","source":"WQP","source_scope":"regional_groundwater","health_guideline_value":1,"health_guideline_source":"OEHHA PHG 2003 (hypertension 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(natural)","code":"FLUORIDE","cas_number":"16984-48-8","group":"inorganics","section":"other_detected","measured_value":0.58,"unit":"mg/L","sample_date":"2025-07-28","source":"WQP","source_scope":"regional_groundwater","health_guideline_value":4,"health_guideline_source":"EPA MCLG","epa_mcl_value":4,"status":"below_limits","detection_limit":null},{"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":"2023-12-31","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 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UCMR5","url":"https://www.epa.gov/dwucmr/fifth-unregulated-contaminant-monitoring-rule"}],"pfas_combined_display":null,"well_counts":{"active":2,"retired":0,"facilities_synced_at":"2026-09-06T14:49:14.849Z"},"historical_wells":[],"has_only_historical_data":false,"pfas_hazard_index":{"value":0.6822,"compounds_used":["PFHXS","PFBS"],"is_partial":true,"threshold":1,"components":[{"code":"PFHXS","value_ng_l":6.8,"hbwc_ng_l":10,"ratio":0.68},{"code":"PFBS","value_ng_l":4.3,"hbwc_ng_l":2000,"ratio":0.0022}]},"tthm_lraa":[{"monitoring_point":"system_wide","value":8.78,"unit":"ug/L","quarters_used":["2022Q4","2023Q4","2024Q4","2025Q4"],"sample_count":5,"mcl":80,"exceeds_mcl":false}],"haa5_lraa":[{"monitoring_point":"system_wide","value":1.53,"unit":"ug/L","quarters_used":["2022Q4","2023Q4","2024Q4","2025Q4"],"sample_count":5,"mcl":60,"exceeds_mcl":false}]}