Lancaster Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 4,873 residents · California
What's In Lancaster's Tap Water?
1
Contaminants Tested
0
Exceed EPA Limits
0
Above EPA Goals
EPA Violation History
22
Violations (last 5yr)
16
Unresolved
17
Health-Related
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: April 1, 2025 – June 30, 2025Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: January 1, 2025 – March 31, 2025Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: October 1, 2024 – December 31, 2024Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: July 1, 2024 – September 30, 2024Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: April 1, 2024 – June 30, 2024Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: January 1, 2024 – March 31, 2024Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: October 1, 2023 – December 31, 2023Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: July 1, 2023 – September 30, 2023Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: April 1, 2023 – June 30, 2023Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: January 1, 2023 – March 31, 2023Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: October 1, 2022 – December 31, 2022Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: July 1, 2022 – September 30, 2022Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 3Resolved
Failed Level 2 Assessment under Revised Total Coliform Rule
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: July 1, 2022 – September 30, 2022Rule: Stage 2 DBPREnforcement: Formal — state order issued
TIER 2Resolved
Violation related to Chlorine
When: July 1, 2022 – September 30, 2022Rule: Stage 1 DBPREnforcement: Formal — state order issued
TIER 3Resolved
Failed Level 2 Assessment under Revised Total Coliform Rule
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: July 1, 2022 – September 30, 2022Rule: Stage 2 DBPREnforcement: Formal — state order issued
TIER 3Resolved
Monitoring Violation
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: July 1, 2022 – July 31, 2022Rule: Total Coliform RuleEnforcement: Formal — state order issued
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: April 1, 2022 – June 30, 2022Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: January 1, 2022 – March 31, 2022Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: October 1, 2021 – December 31, 2021Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 3Resolved
Failed Level 2 Assessment under Revised Total Coliform Rule
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: July 1, 2021 – September 30, 2021Rule: Stage 2 DBPREnforcement: Formal — state order issued
TIER 2Unresolved
Exceeded the Maximum Contaminant Level (running average)
When: July 1, 2021 – September 30, 2021Enforcement: Formal — state order issuedVerify on EPA.gov
TIER 3Resolved
Failed Level 2 Assessment under Revised Total Coliform Rule
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: July 1, 2021 – September 30, 2021Rule: Stage 2 DBPREnforcement: Formal — state order issued
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Lancaster, California tap water receives a grade of D (37/100), which is considered poor. 0 contaminant(s) exceed EPA maximum contaminant levels and 207 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.
What contaminants are in Lancaster's water?
31 contaminants were tested in Lancaster's water supply. No contaminants exceed EPA legal limits (MCLs) or health goals (MCLGs), which is a positive indicator of water quality.
Does Lancaster have any water quality violations?
Yes, Lancaster has 207 EPA violation(s) on record, with the most recent in 2025. Violation types include MCL, MR, MRDL. 90 of these are health-based violations, which are the most serious category.
Do I need a water filter in Lancaster?
Lancaster water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. All contaminants are within health goals.
Where does Lancaster's tap water come from?
Lancaster's drinking water is sourced from groundwater and supplied by SUNDALE MUTUAL WATER COMPANY A, B and 2 other water system(s). The system serves approximately 4,873 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Lancaster's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Lancaster's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Lancaster's water compare to other cities in California?
Lancaster's water quality score of 37/100 earns a grade of D, which is considered poor. This is a concerning score that suggests significant water quality issues. Visit our California state page to see how all cities in the state compare.
What should I do if I'm concerned about Lancaster's water quality?
If you have concerns about Lancaster's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (SUNDALE MUTUAL WATER COMPANY A, B) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.