{"schema_version":"1.2","pwsid":"WI1570113","system_name":"LA VALLE WATERWORKS","city":"LA VALLE","state":"WI","population_served":365,"source_type":"GW","summary":"LA VALLE WATERWORKS serves approximately 365 people in LA VALLE, Wisconsin. Based on contaminant analyses from DNR, WQP, EPA ECHO, 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 Benzene at 2.21 ug/L, which is 14.7x the health guideline. Data is drawn from source-level compliance monitoring and covers 2014 through 2026. Results reflect conditions at the point of collection (wells, treatment plants), not necessarily at the tap.","data_period":{"start":"2014-07-10","end":"2026-04-06"},"contaminants_tested":143,"contaminants_detected":22,"exceedances":0,"guideline_exceedances":3,"contaminants":[{"name":"Chlorine (total residual)","code":"0700_TOTAL","cas_number":null,"group":"disinfectants","section":"other_detected","measured_value":0.48,"unit":"mg/L","sample_date":"2026-04-06","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":"Chlorine (free)","code":"0700","cas_number":null,"group":"disinfectants","section":"other_detected","measured_value":0.73,"unit":"mg/L","sample_date":"2026-03-02","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":"Uranium","code":"4006","cas_number":"7440-61-1","group":"radionuclides","section":"other_detected","measured_value":0.12,"unit":"ug/L","sample_date":"2026-02-23","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.0005,"health_guideline_source":"OEHHA PHG","epa_mcl_value":0.03,"status":"below_limits","detection_limit":null},{"name":"Combined Radium (226+228)","code":"4010","cas_number":null,"group":"radionuclides","section":"other_detected","measured_value":1.54,"unit":"pCi/L","sample_date":"2026-02-23","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0,"health_guideline_source":"EPA MCLG","epa_mcl_value":5,"status":"below_limits","detection_limit":null},{"name":"Gross Alpha Radiation (excluding Radon and Uranium)","code":"4000_EXCL","cas_number":null,"group":"radionuclides","section":"other_detected","measured_value":0.845,"unit":"pCi/L","sample_date":"2026-02-23","source":"DNR","source_scope":"source_monitoring","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":15,"status":"below_limits","detection_limit":null},{"name":"Nitrate (as N)","code":"NITRATE","cas_number":"14797-55-8","group":"inorganics","section":"other_detected","measured_value":1.09,"unit":"mg/L","sample_date":"2025-08-18","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":"Benzene","code":"2990","cas_number":null,"group":"vocs","section":"guideline_exceedance","measured_value":2.21,"unit":"ug/L","sample_date":"2025-07-28","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.00015,"health_guideline_source":"OEHHA PHG","epa_mcl_value":0.005,"status":"exceeds_guideline","detection_limit":null},{"name":"Ethylbenzene","code":"2966","cas_number":null,"group":"other","section":"other_detected","measured_value":2.59,"unit":"ug/L","sample_date":"2025-07-28","source":"DNR","source_scope":"source_monitoring","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":null},{"name":"Toluene","code":"2964","cas_number":null,"group":"other","section":"other_detected","measured_value":2.71,"unit":"ug/L","sample_date":"2025-07-28","source":"DNR","source_scope":"source_monitoring","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":null},{"name":"Styrene","code":"2955","cas_number":null,"group":"other","section":"other_detected","measured_value":2.89,"unit":"ug/L","sample_date":"2025-07-28","source":"DNR","source_scope":"source_monitoring","health_guideline_value":null,"health_guideline_source":null,"epa_mcl_value":null,"status":"detected","detection_limit":null},{"name":"Total Xylenes","code":"2969","cas_number":"1330-20-7","group":"organic","section":"other_detected","measured_value":4.65,"unit":"ug/L","sample_date":"2025-07-28","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.5,"health_guideline_source":"WHO Guideline","epa_mcl_value":10,"status":"below_limits","detection_limit":null},{"name":"1,2-Dichloroethane","code":"2005","cas_number":null,"group":"vocs","section":"other_detected","measured_value":0.15,"unit":"ug/L","sample_date":"2024-09-09","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.0004,"health_guideline_source":"OEHHA PHG","epa_mcl_value":0.005,"status":"below_limits","detection_limit":null},{"name":"Chloramines","code":"0600","cas_number":null,"group":"disinfectants","section":"other_detected","measured_value":0.07,"unit":"mg/L","sample_date":"2024-02-19","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":"Chromium (total)","code":"CHROMIUM","cas_number":"7440-47-3","group":"inorganics","section":"other_detected","measured_value":0.0025,"unit":"mg/L","sample_date":"2024-01-18","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":"Barium","code":"BARIUM","cas_number":"7440-39-3","group":"inorganics","section":"other_detected","measured_value":0.0096,"unit":"mg/L","sample_date":"2024-01-18","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":"Nitrite (as 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(natural)","code":"FLUORIDE","cas_number":"16984-48-8","group":"inorganics","section":"other_detected","measured_value":0.9,"unit":"mg/L","sample_date":"2021-08-10","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":"Arsenic","code":"ARSENIC","cas_number":"7440-38-2","group":"inorganics","section":"other_detected","measured_value":0.26,"unit":"ug/L","sample_date":"2014-07-10","source":"WQP","source_scope":"regional_groundwater","health_guideline_value":0.000004,"health_guideline_source":"OEHHA PHG","epa_mcl_value":0.01,"status":"exceeds_guideline","detection_limit":null},{"name":"Total Trihalomethanes 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ECHO","url":"https://echo.epa.gov/"}],"pfas_combined_display":null,"well_counts":{"active":1,"retired":2,"facilities_synced_at":"2026-04-11T13:48:07.246Z"},"historical_wells":[{"state_facility_id":"1","facility_name":"BG932","deactivation_date":"2024-10-31","top_contaminant":"Benzene","top_contaminant_code":"2990","max_value":370,"unit":"ug/L","classification":"above_mcl","mcl_or_phg_value":5,"mcl_or_phg_unit":"ug/L","validated_reason":null}],"has_only_historical_data":false,"pfas_hazard_index":null,"tthm_lraa":[],"haa5_lraa":[]}