What was found in West Covina'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 | 10780 µg/L 108% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2019 | 1/2 | SYR4 |
| Nitrate | 10000 µg/L 100% of the EPA limit 10000 µg/L Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2019 | 2/2 | SYR4 |
| Fluoride | 477.5 µg/L 12% of the EPA limit 4000 µg/L Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2019 | 2/2 | SYR4 |
| Barium | 146 µg/L 7.3% of the EPA limit 2000 µg/L Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2019 | 2/2 | SYR4 |
| TTHM | 70.95 µg/L 89% of the EPA limit 80 µg/L Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2019
Highest in the city: 79 µg/L — COVINA VALLEY WATER COMPANY - WHOLESALE · 0 people · 2019 | 2/2 | SYR4 |
| Chloroform | 23.4 µg/L No EPA limit set Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2019
Highest in the city: 47.15 µg/L — COVINA VALLEY WATER COMPANY - WHOLESALE · 0 people · 2019 | 2/2 | SYR4 |
| Dibromochloromethane | 27 µg/L No EPA limit set Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2019
Highest in the city: 33.3 µg/L — COVINA VALLEY WATER COMPANY - WHOLESALE · 0 people · 2019 | 2/2 | SYR4 |
| Total Haloacetic Acids (HAA5) | 26 µg/L 43% of the EPA limit 60 µg/L Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2019
Highest in the city: 31.3 µg/L — COVINA VALLEY WATER COMPANY - WHOLESALE · 0 people · 2019 | 2/2 | SYR4 |
| Bromoform | 25 µg/L No EPA limit set Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2019
Highest in the city: 28.9 µg/L — COVINA VALLEY WATER COMPANY - WHOLESALE · 0 people · 2019 | 2/2 | SYR4 |
| Bromodichloromethane | 17.1 µg/L No EPA limit set Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2019
Highest in the city: 24.25 µg/L — COVINA VALLEY WATER COMPANY - WHOLESALE · 0 people · 2019 | 2/2 | SYR4 |
| Combined Uranium | 23.84 µg/L 79% of the EPA limit 30 µg/L Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2019 | 2/2 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 22 µg/L 367% of the EPA limit, at the 95th percentile of samples — 6 µg/L Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2018 | 1/2 | SYR4 |
| Dichloroacetic Acid | 15 µg/L No EPA limit set Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2019
Highest in the city: 17 µg/L — COVINA VALLEY WATER COMPANY - WHOLESALE · 0 people · 2019 | 2/2 | SYR4 |
| Dibromoacetic Acid | 8.7 µg/L No EPA limit set Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2019
Highest in the city: 15 µg/L — COVINA VALLEY WATER COMPANY - WHOLESALE · 0 people · 2019 | 2/2 | SYR4 |
| Trichloroacetic Acid | 9.775 µg/L No EPA limit set Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2019
Highest in the city: 14 µg/L — COVINA VALLEY WATER COMPANY - WHOLESALE · 0 people · 2019 | 2/2 | SYR4 |
| Lithium | 9.8 µg/L No EPA limit set Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2024 | 1/2 | UCMR-5 |
| Arsenic | 8.75 µg/L 88% of the EPA limit 10 µg/L Highest in the city: COVINA VALLEY WATER COMPANY - WHOLESALE · 0 people · 2019 | 1/2 | SYR4 |
| Selenium | 5.2 µg/L 10% of the EPA limit 50 µg/L Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2019 | 1/2 | SYR4 |
| Monobromoacetic Acid | 1.7 µg/L No EPA limit set Highest in the city: COVINA VALLEY WATER COMPANY - WHOLESALE · 0 people · 2019 | 1/2 | SYR4 |
| PFOA | 0.0057 µg/L No EPA limit set Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2024 | 1/2 | UCMR-5 |
| PFBS | 0.0044 µg/L No EPA limit set Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2024 | 1/2 | UCMR-5 |
| PFOS | 0.0044 µg/L No EPA limit set Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2024 | 1/2 | UCMR-5 |
| Pfhxa | 0.0043 µg/L No EPA limit set Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2024 | 1/2 | UCMR-5 |
| Pfpea | 0.0040 µg/L No EPA limit set Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2024 | 1/2 | UCMR-5 |
| PFHXS | 0.0036 µg/L No EPA limit set Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2024 | 1/2 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: VALENCIA HEIGHTS WATER CO. · 7,775 people · 2023 | 1/2 | 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 West Covina
| Supplier | Population served |
|---|---|
| VALENCIA HEIGHTS WATER CO. | 7,775 |
| COVINA VALLEY WATER COMPANY - WHOLESALE | 0 |
Frequently asked questions about West Covina tap water
Is West Covina tap water safe to drink?
EPA testing detected 26 contaminants in the water serving West Covina. 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 West Covina?
2 public water suppliers report drinking-water monitoring for West Covina, California to the EPA. Each is listed above with its population served.
What contaminants are in West Covina's water?
The contaminants EPA monitoring detected in West Covina 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.