CA / Lancaster
CA · Tap water records
Lancaster tap water, in plain English
Here is what the EPA's own data shows about tap water in Lancaster. According to EPA SDWIS data retrieved June 2026, Lancaster is served by 19 active community water systems, together reported to serve about 8,296 people.
As of June 2026, EPA records show 616 violations across the community water system(s) serving Lancaster, going back to the earliest EPA record. 289 of these are classified by the EPA as health-based (a contaminant recorded above the limit the EPA tracks); the rest are monitoring or reporting violations. Each is listed by system below, with its status.
What the EPA has on record, by system
Land Projects Mutual Water Co.
2,800 served · groundwater · PWSID CA1910246 - Health-based Arsenic: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 114 times between January 2016 and April 2025. The EPA record lists a level of 0.014 MG/L; the limit (MCL) is 0.01 MG/L. EPA records do not show all of these as returned to compliance.
- Health-based Chlorine: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 4 times in July 2022. The EPA record for these does not include a measured level. EPA records do not show all of these as returned to compliance.
- Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 37 times between May 2017 and July 2022. All have since returned to compliance, per EPA records.
- Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times between July 2021 and July 2022. EPA records do not show all of these as returned to compliance.
- Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times between July 2021 and July 2022. EPA records do not show all of these as returned to compliance.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in October 2020. All have since returned to compliance, per EPA records.
- Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between April 2019 and April 2020. All have since returned to compliance, per EPA records.
- Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2017. All have since returned to compliance, per EPA records.
- Monitoring Aluminum: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Arsenic: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Barium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Cadmium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Chromium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Fluoride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Mercury: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Nickel: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Nitrite: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Antimony, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Beryllium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Thallium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Selenium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Perchlorate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Trichlorofluoromethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring METHYL TERT-BUTYL ETHER: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring 1,2,4-Trichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring cis-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring 1,3-DICHLOROPROPENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring TRICHLOROTRIFLUOROETHANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Xylenes, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring DICHLOROMETHANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring o-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring p-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Vinyl chloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring 1,1-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring 1,1-Dichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring trans-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring 1,2-Dichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring 1,1,1-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Carbon tetrachloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring 1,2-Dichloropropane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Trichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring 1,1,2-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Tetrachloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring 1,1,2,2-Tetrachloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring CHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Benzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Toluene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Ethylbenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Styrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Endrin: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring BHC-GAMMA: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Methoxychlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Toxaphene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Dalapon: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Diquat: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Endothall: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Glyphosate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Di(2-ethylhexyl) adipate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring OXAMYL: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Simazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Di(2-ethylhexyl) phthalate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Picloram: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Dinoseb: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Hexachlorocyclopentadiene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Carbofuran: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Atrazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring LASSO: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring 2,3,7,8-TCDD: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Heptachlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Heptachlor epoxide: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring 2,4-D: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring 2,4,5-TP: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring HEXACHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Benzo(a)pyrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Pentachlorophenol: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Total Polychlorinated Biphenyls (PCB): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring 1,2-DIBROMO-3-CHLOROPROPANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring ETHYLENE DIBROMIDE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Chlordane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring BENTAZON: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring MOLINATE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring THIOBENCARB (BOLERO): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Radium-226: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Radium-228: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Gross Alpha Particle Activity: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Color: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. EPA records do not show all of these as returned to compliance.
- Monitoring Foaming Agents (Surfactants): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. EPA records do not show all of these as returned to compliance.
- Monitoring Iron: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. EPA records do not show all of these as returned to compliance.
- Monitoring Manganese: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. EPA records do not show all of these as returned to compliance.
- Monitoring Odor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. EPA records do not show all of these as returned to compliance.
- Monitoring Silver: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. EPA records do not show all of these as returned to compliance.
- Monitoring Turbidity: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Zinc: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. EPA records do not show all of these as returned to compliance.
- Monitoring Chloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. EPA records do not show all of these as returned to compliance.
- Monitoring Sulfate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. EPA records do not show all of these as returned to compliance.
- Monitoring Bicarbonate as HCO3: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Magnesium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Sodium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring pH: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Total Hardness (Gr/Gal)D: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Alkalinity, Carbonate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
- Monitoring Calcium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2014. All have since returned to compliance, per EPA records.
Sundale Mutual Water Company A, B
1,050 served · groundwater · PWSID CA1900563 - Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in December 2021. All have since returned to compliance, per EPA records.
- Monitoring Groundwater Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between May 2015 and July 2016. All have since returned to compliance, per EPA records.
Averydale Mwc
1,023 served · groundwater · PWSID CA1910023 - Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2024. All have since returned to compliance, per EPA records.
White Fence Farms Mwc No.3
749 served · surface water · PWSID CA1900523 - Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times in October 2022. EPA records do not show all of these as returned to compliance.
- Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times in October 2022. EPA records do not show all of these as returned to compliance.
- Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2011. All have since returned to compliance, per EPA records.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in November 2006. All have since returned to compliance, per EPA records.
Landale Mutual Water Company
550 served · groundwater · PWSID CA1900809 - Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2019. All have since returned to compliance, per EPA records.
Sherwood Mobile Home Park
540 served · groundwater · PWSID CA1900907 - Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Antelope Park Mutual Water Company
445 served · groundwater · PWSID CA1900794 - Monitoring Coliform (Pre-TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2020. All have since returned to compliance, per EPA records.
Western Skies Mobile Home Park
198 served · groundwater · PWSID CA1900541 - Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 1993 and October 2019. EPA records do not show all of these as returned to compliance.
Mettler Valley Mutual
160 served · groundwater · PWSID CA1900100 - Health-based Arsenic: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 72 times between January 2016 and April 2024. The EPA record lists a level of 0.014 MG/L; the limit (MCL) is 0.01 MG/L. EPA records do not show all of these as returned to compliance.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in October 2018. All have since returned to compliance, per EPA records.
Aqua J. Mutual Water Company
158 served · groundwater · PWSID CA1900936 - Health-based Coliform (Pre-TCR): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in October 2020. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2019. All have since returned to compliance, per EPA records.
- Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Wilsona Gardens Mutual
129 served · groundwater · PWSID CA1900155 - Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times between January 2024 and September 2025. EPA records do not show all of these as returned to compliance.
- Monitoring COLIPHAGE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in October 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2024. All have since returned to compliance, per EPA records.
- Monitoring Coliform (Pre-TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2019. All have since returned to compliance, per EPA records.
Evergreen Mutual Water Company
98 served · groundwater · PWSID CA1900804 - Monitoring Coliform (Pre-TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in December 2020. All have since returned to compliance, per EPA records.
Lancaster Water Company
80 served · groundwater · PWSID CA1900808 - Health-based Coliform (Pre-TCR): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in June 2021. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Health-based Coliform (TCR): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in December 2015. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Monitoring LEAD AND COPPER RULE REVISIONS: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Coliform (Pre-TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2018. EPA records do not show all of these as returned to compliance.
Reesedale Mutual
76 served · groundwater · PWSID CA1900145 - Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between November 2023 and December 2023. All have since returned to compliance, per EPA records.
- Monitoring Coliform (Pre-TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between November 2023 and December 2023. EPA records do not show all of these as returned to compliance.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2017. All have since returned to compliance, per EPA records.
- Monitoring Coliform (TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2016. All have since returned to compliance, per EPA records.
Tierra Bonita Mutual Water
75 served · groundwater · PWSID CA1900154 - Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 1993 and October 2019. EPA records do not show all of these as returned to compliance.
- Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Lancaster Park Mobile Home Park
60 served · groundwater · PWSID CA1900038 - Health-based Arsenic: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 63 times between January 2016 and July 2025. The EPA record lists a level of 0.015 MG/L; the limit (MCL) is 0.01 MG/L. EPA records do not show all of these as returned to compliance.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between June 2017 and January 2018. All have since returned to compliance, per EPA records.
- Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2017. All have since returned to compliance, per EPA records.
Bleich Flats Mutual
42 served · groundwater · PWSID CA1900075 - Health-based Coliform (Pre-TCR): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 3 times in June 2021. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Monitoring Coliform (Pre-TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in September 2017. EPA records do not show all of these as returned to compliance.
Colorado Mutual Water Company
39 served · groundwater · PWSID CA1900801 - Health-based LEAD AND COPPER RULE REVISIONS: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in October 2024. The EPA record for these does not include a measured level. EPA records do not show all of these as returned to compliance.
- Monitoring LEAD AND COPPER RULE REVISIONS: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 1993. All have since returned to compliance, per EPA records.
Mitchell'S Avenue E Mobile Home Park
24 served · groundwater · PWSID CA1900785 - Health-based Arsenic: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 29 times between January 2016 and April 2024. The EPA record lists a level of 0.02 MG/L; the limit (MCL) is 0.01 MG/L. EPA records do not show all of these as returned to compliance.
- Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2019. All have since returned to compliance, per EPA records.
What this means
A health-based violation means a contaminant was recorded above the limit the EPA tracks for it. A monitoring or reporting violation means a required test or report was late or missed — not that a contaminant was measured above a limit. “Returned to compliance” means the EPA recorded the issue as resolved.
This page summarizes the EPA's own records and does not assess whether your water is safe to drink. For the most current details, you can verify every record directly with the EPA, and contact your water system with questions.
Source: U.S. EPA Envirofacts SDWIS, retrieved June 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.