{"schema_version":"1.2","pwsid":"WI2681104","system_name":"KNOLLCREST","city":"MIDDLETON","state":"WI","population_served":66,"source_type":"GW","summary":"KNOLLCREST serves approximately 66 people in MIDDLETON, 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. 2 contaminants exceed health-based guidelines. The most significant finding is Lead (90th Percentile) at 0.013645 mg/L, which is 68.2x 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":"2014-07-09","end":"2026-08-17"},"contaminants_tested":70,"contaminants_detected":3,"exceedances":0,"guideline_exceedances":2,"contaminants":[{"name":"Di(2-ethylhexyl) phthalate","code":"2046","cas_number":null,"group":"vocs","section":"other_detected","measured_value":4,"unit":"ug/L","sample_date":"2026-08-17","source":"DNR","source_scope":"source_monitoring","health_guideline_value":0.008,"health_guideline_source":"WHO Guideline","epa_mcl_value":0.006,"status":"below_limits","detection_limit":null},{"name":"Nitrate (as N)","code":"NITRATE","cas_number":"14797-55-8","group":"inorganics","section":"other_detected","measured_value":3.53,"unit":"mg/L","sample_date":"2014-07-09","source":"WQP","source_scope":"regional_groundwater","health_guideline_value":10,"health_guideline_source":"EPA MCLG","epa_mcl_value":10,"status":"below_limits","detection_limit":null},{"name":"Barium","code":"BARIUM","cas_number":"7440-39-3","group":"inorganics","section":"other_detected","measured_value":0.084,"unit":"mg/L","sample_date":"2022-06-01","source":"WQP","source_scope":"regional_groundwater","health_guideline_value":1,"health_guideline_source":"OEHHA PHG 2003 (hypertension endpoint)","epa_mcl_value":2,"status":"below_limits","detection_limit":null},{"name":"Arsenic","code":"ARSENIC","cas_number":"7440-38-2","group":"inorganics","section":"other_detected","measured_value":7.71,"unit":"ug/L","sample_date":"2022-06-01","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":"Chromium (total)","code":"CHROMIUM","cas_number":"7440-47-3","group":"inorganics","section":"other_detected","measured_value":190,"unit":"ug/L","sample_date":"2022-05-24","source":"WQP","source_scope":"regional_groundwater","health_guideline_value":0.1,"health_guideline_source":"EPA MCLG","epa_mcl_value":0.1,"status":"exceeds_legal_limit","detection_limit":null},{"name":"Fluoride (natural)","code":"FLUORIDE","cas_number":"16984-48-8","group":"inorganics","section":"other_detected","measured_value":0.08,"unit":"mg/L","sample_date":"2014-11-05","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":"guideline_exceedance","measured_value":0.01365,"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":1150,"unit":"ug/L","sample_date":"2023-08-01","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}],"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":1,"retired":0,"facilities_synced_at":"2026-10-15T05:00:54.057Z"},"historical_wells":[],"has_only_historical_data":false,"pfas_hazard_index":null,"tthm_lraa":[],"haa5_lraa":[]}