{"schema_version":"1.2","pwsid":"WI7440129","system_name":"THREE LAKES SANITARY DISTRICT","city":"THREE LAKES","state":"WI","population_served":500,"source_type":"GW","summary":"THREE LAKES SANITARY DISTRICT serves approximately 500 people in THREE LAKES, Wisconsin. Based on contaminant analyses from DNR, WQP, EPA ECHO, 0 contaminants have been measured above federal EPA standards (MCL) and 3 exceed health-based guidelines. The most significant finding is Lead (90th Percentile) at 0.0112 mg/L, which is 56x the health guideline. Data is drawn from source-level compliance monitoring and covers 2002 through 2025. Results reflect conditions at the point of collection (wells, treatment plants), not necessarily at the tap.","data_period":{"start":"2002-09-10","end":"2025-09-17"},"contaminants_tested":81,"contaminants_detected":14,"exceedances":0,"guideline_exceedances":3,"contaminants":[{"name":"Nitrate (as N)","code":"NITRATE","cas_number":"14797-55-8","group":"inorganics","section":"other_detected","measured_value":2.6,"unit":"mg/L","sample_date":"2025-09-17","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":"Chlorine (free)","code":"0700","cas_number":null,"group":"disinfectants","section":"other_detected","measured_value":0.05,"unit":"mg/L","sample_date":"2023-10-09","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":"Beryllium","code":"1006","cas_number":null,"group":"inorganics","section":"other_detected","measured_value":0.00011,"unit":"mg/L","sample_date":"2023-09-25","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.004,"health_guideline_source":"EPA MCLG","epa_mcl_value":0.004,"status":"below_limits","detection_limit":null},{"name":"Chromium (total)","code":"CHROMIUM","cas_number":"7440-47-3","group":"inorganics","section":"other_detected","measured_value":0.002,"unit":"mg/L","sample_date":"2023-09-25","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.1,"health_guideline_source":"EPA MCLG","epa_mcl_value":0.1,"status":"below_limits","detection_limit":null},{"name":"Antimony","code":"1052","cas_number":null,"group":"inorganics","section":"other_detected","measured_value":0.0014,"unit":"mg/L","sample_date":"2023-09-25","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.006,"health_guideline_source":"EPA MCLG","epa_mcl_value":0.006,"status":"below_limits","detection_limit":null},{"name":"Nickel","code":"1036","cas_number":null,"group":"inorganics","section":"other_detected","measured_value":0.0086,"unit":"mg/L","sample_date":"2023-09-25","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":"Arsenic","code":"ARSENIC","cas_number":"7440-38-2","group":"inorganics","section":"guideline_exceedance","measured_value":0.0034,"unit":"mg/L","sample_date":"2023-09-25","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":0.047,"unit":"mg/L","sample_date":"2023-09-25","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":"Fluoride (natural)","code":"FLUORIDE","cas_number":"16984-48-8","group":"inorganics","section":"other_detected","measured_value":0.057,"unit":"mg/L","sample_date":"2023-09-25","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":"9Cl-PF3ONS (9-Chlorohexadecafluoro-3-oxanonane-1-sulfonate)","code":"9CL_PF3ONS","cas_number":null,"group":"pfas","section":"other_detected","measured_value":0.66,"unit":"ng/L","sample_date":"2023-06-21","source":"DNR","source_scope":"source_monitoring","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":null},{"name":"Lead (90th Percentile)","code":"PB90","cas_number":"7439-92-1","group":"lead_copper","section":"guideline_exceedance","measured_value":0.0112,"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":"guideline_exceedance","measured_value":700,"unit":"ug/L","sample_date":"2023-09-25","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.3,"health_guideline_source":"OEHHA PHG","epa_mcl_value":null,"status":"exceeds_guideline","detection_limit":null},{"name":"PFHxA (Perfluorohexanoic Acid)","code":"PFHXA","cas_number":"307-24-4","group":"pfas","section":"pfas","measured_value":0.62,"unit":"ng/L","sample_date":"2023-06-21","source":"DNR","source_scope":"source_monitoring","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":null},{"name":"PFBS (Perfluorobutane Sulfonate)","code":"PFBS","cas_number":"375-73-5","group":"pfas","section":"pfas","measured_value":3.8,"unit":"ng/L","sample_date":"2023-06-21","source":"DNR","source_scope":"source_monitoring","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","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/"}],"pfas_combined_display":null,"well_counts":{"active":2,"retired":1,"facilities_synced_at":"2026-04-11T13:48:07.246Z"},"historical_wells":[],"has_only_historical_data":false,"pfas_hazard_index":{"value":0.0019,"compounds_used":["PFBS"],"is_partial":true,"threshold":1,"components":[{"code":"PFBS","value_ng_l":3.8,"hbwc_ng_l":2000,"ratio":0.0019}]},"tthm_lraa":[],"haa5_lraa":[]}