{"schema_version":"1.2","pwsid":"WI4050453","system_name":"DE PERE WATERWORKS SA 1","city":"DE PERE","state":"WI","population_served":25660,"source_type":"SW","summary":"DE PERE WATERWORKS SA 1 serves approximately 25,660 people in DE PERE, Wisconsin. Based on contaminant analyses from DNR, WQP, EPA ECHO, EPA UCMR5, 2 contaminants have been measured above federal EPA standards (MCL) and 5 exceed health-based guidelines. The most significant finding is Combined Radium (226+228) at 9.5 pCi/L, which is 1.9x the EPA legal limit. Data is drawn from source-level compliance monitoring and covers 1995 through 2026. Results reflect conditions at the point of collection (wells, treatment plants), not necessarily at the tap.","data_period":{"start":"1995-06-14","end":"2026-03-18"},"contaminants_tested":44,"contaminants_detected":15,"exceedances":2,"guideline_exceedances":5,"contaminants":[{"name":"Chlorine (free)","code":"0700","cas_number":null,"group":"disinfectants","section":"other_detected","measured_value":0.98,"unit":"mg/L","sample_date":"2026-03-18","source":"DNR","source_scope":"source_monitoring","health_guideline_value":4,"health_guideline_source":"EPA MCLG","epa_mcl_value":4,"status":"below_limits","detection_limit":null},{"name":"Nickel","code":"1036","cas_number":null,"group":"inorganics","section":"other_detected","measured_value":0.0039,"unit":"mg/L","sample_date":"2026-01-21","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.012,"health_guideline_source":"OEHHA PHG","epa_mcl_value":null,"status":"below_limits","detection_limit":null},{"name":"Selenium","code":"1045","cas_number":null,"group":"inorganics","section":"other_detected","measured_value":0.0015,"unit":"mg/L","sample_date":"2026-01-21","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.05,"health_guideline_source":"EPA MCLG","epa_mcl_value":0.05,"status":"below_limits","detection_limit":null},{"name":"Arsenic","code":"ARSENIC","cas_number":"7440-38-2","group":"inorganics","section":"guideline_exceedance","measured_value":0.0017,"unit":"mg/L","sample_date":"2026-01-21","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.000004,"health_guideline_source":"OEHHA PHG","epa_mcl_value":0.01,"status":"exceeds_guideline","detection_limit":null},{"name":"Barium","code":"BARIUM","cas_number":"7440-39-3","group":"inorganics","section":"other_detected","measured_value":0.043,"unit":"mg/L","sample_date":"2026-01-21","source":"DNR","source_scope":"source_monitoring","health_guideline_value":1,"health_guideline_source":"OEHHA PHG 2003 (hypertension endpoint)","epa_mcl_value":2,"status":"below_limits","detection_limit":null},{"name":"Uranium","code":"4006","cas_number":"7440-61-1","group":"radionuclides","section":"guideline_exceedance","measured_value":0.913,"unit":"ug/L","sample_date":"2026-01-21","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.0005,"health_guideline_source":"OEHHA PHG","epa_mcl_value":0.03,"status":"exceeds_guideline","detection_limit":null},{"name":"Fluoride (natural)","code":"FLUORIDE","cas_number":"16984-48-8","group":"inorganics","section":"other_detected","measured_value":2.4,"unit":"mg/L","sample_date":"2026-01-21","source":"DNR","source_scope":"source_monitoring","health_guideline_value":4,"health_guideline_source":"EPA MCLG","epa_mcl_value":4,"status":"below_limits","detection_limit":null},{"name":"Combined Radium (226+228)","code":"4010","cas_number":null,"group":"radionuclides","section":"legal_violation","measured_value":9.5,"unit":"pCi/L","sample_date":"2026-01-21","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0,"health_guideline_source":"EPA MCLG","epa_mcl_value":5,"status":"exceeds_legal_limit","detection_limit":null},{"name":"Haloacetic Acids (HAA5)","code":"2456","cas_number":null,"group":"dbps","section":"other_detected","measured_value":22.09,"unit":"ug/L","sample_date":"2026-01-21","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":"Gross Alpha Radiation (excluding Radon and Uranium)","code":"4000_EXCL","cas_number":null,"group":"radionuclides","section":"legal_violation","measured_value":27.2,"unit":"pCi/L","sample_date":"2026-01-21","source":"DNR","source_scope":"source_monitoring","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":15,"status":"exceeds_legal_limit","detection_limit":null},{"name":"Total Trihalomethanes (TTHMs)","code":"2950","cas_number":null,"group":"dbps","section":"other_detected","measured_value":45,"unit":"ug/L","sample_date":"2026-01-21","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":"Nitrate (as N)","code":"NITRATE","cas_number":"14797-55-8","group":"inorganics","section":"other_detected","measured_value":0.06,"unit":"mg/L","sample_date":"2024-01-23","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":"Lead (90th Percentile)","code":"PB90","cas_number":"7439-92-1","group":"lead_copper","section":"guideline_exceedance","measured_value":0.00066,"unit":"mg/L","sample_date":"2023-09-30","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},{"name":"Copper (90th Percentile)","code":"COPPER","cas_number":"7440-50-8","group":"lead_copper","section":"other_detected","measured_value":140,"unit":"ug/L","sample_date":"2023-07-21","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.3,"health_guideline_source":"OEHHA PHG","epa_mcl_value":null,"status":"below_limits","detection_limit":null},{"name":"PFOA (Perfluorooctanoic Acid)","code":"PFOA","cas_number":"335-67-1","group":"pfas","section":"pfas","measured_value":0.52,"unit":"ng/L","sample_date":"2023-01-24","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0,"health_guideline_source":"EPA MCLG","epa_mcl_value":0.004,"status":"below_limits","detection_limit":null}],"sources":[{"name":"DNR","url":"https://apps.dnr.wi.gov/dwsportalpub"},{"name":"WQP","url":"https://www.waterqualitydata.us/"},{"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":{"value":0.52,"unit":"ng/L","sample_date":"2023-01-24","note":"Legacy 2016 EPA Health Advisory combined PFOA+PFOS metric. Not a current MCL."},"well_counts":{"active":4,"retired":2,"facilities_synced_at":"2026-04-11T13:48:07.246Z"},"historical_wells":[],"has_only_historical_data":false,"pfas_hazard_index":null,"tthm_lraa":[{"monitoring_point":"system_wide","value":45,"unit":"ug/L","quarters_used":["2024Q2","2024Q3","2024Q4","2026Q1"],"sample_count":16,"mcl":80,"exceeds_mcl":false}],"haa5_lraa":[{"monitoring_point":"system_wide","value":22.09,"unit":"ug/L","quarters_used":["2024Q2","2024Q3","2024Q4","2026Q1"],"sample_count":16,"mcl":60,"exceeds_mcl":false}]}