{"schema_version":"1.2","pwsid":"IL1470200","system_name":"DE LAND","city":"WESTVILLE","state":"IL","population_served":446,"source_type":"GW","summary":"DE LAND serves approximately 446 people in WESTVILLE, Illinois. 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 Arsenic at 0.0037 mg/L, which is 925x the health guideline. Data is drawn from source-level compliance monitoring and covers 2007 through 2028. Results reflect conditions at the point of collection (wells, treatment plants), not necessarily at the tap.","data_period":{"start":"2007-08-01","end":"2028-12-31"},"contaminants_tested":6,"contaminants_detected":6,"exceedances":0,"guideline_exceedances":2,"contaminants":[{"name":"Total Trihalomethanes (TTHMs)","code":"2950","cas_number":null,"group":"dbps","section":"other_detected","measured_value":27,"unit":"ug/L","sample_date":"2026-09-23","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":"Arsenic","code":"ARSENIC","cas_number":"7440-38-2","group":"inorganics","section":"guideline_exceedance","measured_value":0.0037,"unit":"mg/L","sample_date":"2026-08-12","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":"Nitrate (as N)","code":"NITRATE","cas_number":"14797-55-8","group":"inorganics","section":"other_detected","measured_value":1.6,"unit":"mg/L","sample_date":"2026-02-17","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":"Nitrite (as N)","code":"1041","cas_number":null,"group":"inorganics","section":"other_detected","measured_value":0.41,"unit":"mg/L","sample_date":"2026-02-17","source":"DNR","source_scope":"source_monitoring","health_guideline_value":1,"health_guideline_source":"EPA MCLG","epa_mcl_value":1,"status":"below_limits","detection_limit":null},{"name":"Barium","code":"BARIUM","cas_number":"7440-39-3","group":"inorganics","section":"other_detected","measured_value":0.00612,"unit":"mg/L","sample_date":"2007-08-03","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":"Chromium (total)","code":"CHROMIUM","cas_number":"7440-47-3","group":"inorganics","section":"other_detected","measured_value":2.4,"unit":"ug/L","sample_date":"2007-08-03","source":"WQP","source_scope":"regional_groundwater","health_guideline_value":0.1,"health_guideline_source":"EPA MCLG","epa_mcl_value":0.1,"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":"2028-12-31","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 Percentile)","code":"CU90","cas_number":"7440-50-8","group":"lead_copper","section":"guideline_exceedance","measured_value":1.84,"unit":"mg/L","sample_date":"2016-06-30","source":"EPA ECHO","source_scope":"federal_program","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":2,"retired":7,"facilities_synced_at":"2026-10-26T01:13:06.376Z"},"historical_wells":[],"has_only_historical_data":false,"pfas_hazard_index":null,"tthm_lraa":[],"haa5_lraa":[]}