What was found in Lancaster's water
The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate-Nitrite | 5875 µg/L 59% of the EPA limit 10000 µg/L Main supplier: LAND PROJECTS MUTUAL WATER CO. · 2,800 people · 2019
Highest in the city: 705630 µg/L — WILSONA GARDENS MUTUAL · 129 people · 2018 | 14/19 | SYR4 |
| Nitrate | 6000 µg/L 60% of the EPA limit 10000 µg/L Main supplier: LAND PROJECTS MUTUAL WATER CO. · 2,800 people · 2019 | 17/19 | SYR4 |
| Fluoride | 723 µg/L 18% of the EPA limit 4000 µg/L Main supplier: LAND PROJECTS MUTUAL WATER CO. · 2,800 people · 2019
Highest in the city: 983.5 µg/L — MITCHELL'S AVENUE E MOBILE HOME PARK · 24 people · 2017 | 17/19 | SYR4 |
| Barium | 102 µg/L 5.1% of the EPA limit 2000 µg/L Highest in the city: LANCASTER PARK MOBILE HOME PARK · 60 people · 2019 | 6/19 | SYR4 |
| TTHM | 3.56 µg/L 4.5% of the EPA limit 80 µg/L Main supplier: LAND PROJECTS MUTUAL WATER CO. · 2,800 people · 2019
Highest in the city: 75.6 µg/L — WHITE FENCE FARMS MWC NO.3 · 749 people · 2019 | 4/19 | SYR4 |
| Chromium | 40 µg/L 40% of the EPA limit 100 µg/L Highest in the city: METTLER VALLEY MUTUAL · 160 people · 2018 | 11/19 | SYR4 |
| Dibromochloromethane | 1.1 µg/L No EPA limit set Main supplier: LAND PROJECTS MUTUAL WATER CO. · 2,800 people · 2019
Highest in the city: 34.75 µg/L — WHITE FENCE FARMS MWC NO.3 · 749 people · 2019 | 3/19 | SYR4 |
| Bromoform | 3.44 µg/L No EPA limit set Main supplier: LAND PROJECTS MUTUAL WATER CO. · 2,800 people · 2019
Highest in the city: 23.52 µg/L — WHITE FENCE FARMS MWC NO.3 · 749 people · 2019 | 3/19 | SYR4 |
| Arsenic | 17 µg/L 170% of the EPA limit, at the 95th percentile of samples — 10 µg/L Main supplier: LAND PROJECTS MUTUAL WATER CO. · 2,800 people · 2019
Highest in the city: 23.3 µg/L — MITCHELL'S AVENUE E MOBILE HOME PARK · 24 people · 2019 | 8/19 | SYR4 |
| Combined Uranium | 14.8628 µg/L 50% of the EPA limit 30 µg/L Main supplier: LAND PROJECTS MUTUAL WATER CO. · 2,800 people · 2019
Highest in the city: 21.4038 µg/L — BLEICH FLATS MUTUAL · 42 people · 2012 | 14/19 | SYR4 |
| Total Haloacetic Acids (HAA5) | 20.05 µg/L 33% of the EPA limit 60 µg/L Highest in the city: WHITE FENCE FARMS MWC NO.3 · 749 people · 2019 | 1/19 | SYR4 |
| Bromodichloromethane | 18.15 µg/L No EPA limit set Highest in the city: WHITE FENCE FARMS MWC NO.3 · 749 people · 2019 | 2/19 | SYR4 |
| Chloroform | 15.78 µg/L No EPA limit set Highest in the city: WHITE FENCE FARMS MWC NO.3 · 749 people · 2019 | 2/19 | SYR4 |
| Dibromoacetic Acid | 15.18 µg/L No EPA limit set Highest in the city: WHITE FENCE FARMS MWC NO.3 · 749 people · 2019 | 1/19 | SYR4 |
| Copper | 13 µg/L 1% of the EPA limit 1300 µg/L Highest in the city: METTLER VALLEY MUTUAL · 160 people · 2018 | 2/19 | SYR4 |
| Selenium | 11.6 µg/L 23% of the EPA limit 50 µg/L Highest in the city: COLORADO MUTUAL WATER COMPANY · 39 people · 2019 | 5/19 | SYR4 |
| Trichloroacetic Acid | 9.77 µg/L No EPA limit set Highest in the city: WHITE FENCE FARMS MWC NO.3 · 749 people · 2019 | 1/19 | SYR4 |
| Dichloroacetic Acid | 8.29 µg/L No EPA limit set Highest in the city: WHITE FENCE FARMS MWC NO.3 · 749 people · 2019 | 1/19 | SYR4 |
| Lead | 5.2 µg/L 35% of the EPA limit 15 µg/L Highest in the city: METTLER VALLEY MUTUAL · 160 people · 2018 | 2/19 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 4.465 µg/L 74% of the EPA limit 6 µg/L Highest in the city: LANCASTER WATER COMPANY · 80 people · 2015 | 1/19 | SYR4 |
| Monobromoacetic Acid | 1.47 µg/L No EPA limit set Highest in the city: WHITE FENCE FARMS MWC NO.3 · 749 people · 2019 | 1/19 | SYR4 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: LAND PROJECTS MUTUAL WATER CO. · 2,800 people · 2024
Highest in the city: 0.0059 mg/L — WHITE FENCE FARMS MWC NO.3 · 749 people · 2024 | 19/19 | LCR |
Each bar shows the measured level as a share of the EPA limit: green is
well under, amber is close to it, red is over. For lead and copper the
limit applies to exactly the 90th-percentile figure shown, so red there
means a real exceedance. For everything else the limit applies to a
running annual average while the figure is the 95th percentile of the
system's samples — over 100% is worth reading, but is not by itself a
violation.
Formal violations are listed separately.
These are the utilities' own EPA-reported results, not a city-wide
average. A detection means the lab measured the
substance — it isn't the same as exceeding a legal limit. Hover a source
tag to see the EPA program and years behind each figure.
Water suppliers serving Lancaster
Frequently asked questions about Lancaster tap water
Is Lancaster tap water safe to drink?
EPA testing detected 22 contaminants in the water serving Lancaster. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.
How many water suppliers serve Lancaster?
19 public water suppliers report drinking-water monitoring for Lancaster, California to the EPA. Each is listed above with its population served.
What contaminants are in Lancaster's water?
The contaminants EPA monitoring detected in Lancaster include Nitrate-Nitrite, Nitrate, Fluoride, Barium, TTHM. The full list, with the level at the main supplier and the data source, is in the table above.
Where does this data come from?
Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.