What was found in Snohomish'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 | 3537 µg/L 35% of the EPA limit 10000 µg/L Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019 | 3/10 | SYR4 |
| Nitrate | 3520 µg/L 35% of the EPA limit 10000 µg/L Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019 | 3/10 | SYR4 |
| Fluoride | 190 µg/L 4.8% of the EPA limit 4000 µg/L Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019 | 1/10 | SYR4 |
| TTHM | 53.2 µg/L 67% of the EPA limit 80 µg/L Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019
Highest in the city: 81.045 µg/L — ROOSEVELT WATER ASSOCIATION · 3,530 people · 2019 | 6/10 | SYR4 |
| Chloroform | 51.19 µg/L No EPA limit set Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019
Highest in the city: 78.16 µg/L — ROOSEVELT WATER ASSOCIATION · 3,530 people · 2019 | 6/10 | SYR4 |
| Total Haloacetic Acids (HAA5) | 44.35 µg/L 74% of the EPA limit 60 µg/L Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019
Highest in the city: 46.906 µg/L — ROOSEVELT WATER ASSOCIATION · 3,530 people · 2019 | 6/10 | SYR4 |
| Trichloroacetic Acid | 25.65 µg/L No EPA limit set Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019
Highest in the city: 30.96 µg/L — SNOHOMISH CITY OF · 16,367 people · 2019 | 6/10 | SYR4 |
| Dichloroacetic Acid | 17.67 µg/L No EPA limit set Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019
Highest in the city: 20.3 µg/L — ROOSEVELT WATER ASSOCIATION · 3,530 people · 2019 | 6/10 | SYR4 |
| Dibromoacetic Acid | 12.975 µg/L No EPA limit set Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019 | 3/10 | SYR4 |
| Arsenic | 5.6 µg/L 56% of the EPA limit 10 µg/L Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019
Highest in the city: 11.54 µg/L — AQUA COPIA/HORSE COUNTRY ESTATES · 250 people · 2018 | 2/10 | SYR4 |
| Copper | 9.6 µg/L 0.7% of the EPA limit 1300 µg/L Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019 | 2/10 | SYR4 |
| Barium | 7 µg/L 0.4% of the EPA limit 2000 µg/L Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019 | 1/10 | SYR4 |
| Bromodichloromethane | 5 µg/L No EPA limit set Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019 | 6/10 | SYR4 |
| Monobromoacetic Acid | 4.521 µg/L No EPA limit set Highest in the city: ROOSEVELT WATER ASSOCIATION · 3,530 people · 2019 | 1/10 | SYR4 |
| Monochloroacetic Acid | 4.04 µg/L No EPA limit set Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019 | 5/10 | SYR4 |
| Dibromochloromethane | 3.975 µg/L No EPA limit set Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019 | 3/10 | SYR4 |
| Lead | 3 µg/L 20% of the EPA limit 15 µg/L Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019 | 2/10 | SYR4 |
| Chromium | 2 µg/L 2% of the EPA limit 100 µg/L Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019 | 1/10 | SYR4 |
| Bromoform | 0.6000 µg/L No EPA limit set Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2019 | 3/10 | SYR4 |
| PFBS | 0.0094 µg/L No EPA limit set Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2025 | 1/10 | UCMR-5 |
| Pfhxa | 0.0064 µg/L No EPA limit set Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2025 | 1/10 | UCMR-5 |
| Lead | 0.0031 mg/L 21% of the EPA limit 0.0150 mg/L Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2024
Highest in the city: 0.0052 mg/L — PILCHUCK RIVIERA #2 · 107 people · 2023 | 5/10 | LCR |
| Pfpea | 0.0049 µg/L No EPA limit set Main supplier: CROSS VALLEY WATER DISTRICT · 24,695 people · 2025 | 1/10 | UCMR-5 |
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 Snohomish
| Supplier | Population served |
|---|---|
| CROSS VALLEY WATER DISTRICT | 24,695 |
| SNOHOMISH CITY OF | 16,367 |
| ROOSEVELT WATER ASSOCIATION | 3,530 |
| THREE LAKES WATER ASSOCIATION | 2,198 |
| AQUA COPIA/HORSE COUNTRY ESTATES | 250 |
| FOBES WATER DISTRICT | 156 |
| PILCHUCK RIVIERA #2 | 107 |
| MOUNTAIN VIEW TERRACE WATER INC | 87 |
| 60TH STREET WATER WORKS | 35 |
| GREEN VELVET WATER SYSTEM | 26 |
Frequently asked questions about Snohomish tap water
Is Snohomish tap water safe to drink?
EPA testing detected 23 contaminants in the water serving Snohomish. 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 Snohomish?
10 public water suppliers report drinking-water monitoring for Snohomish, Washington to the EPA. Each is listed above with its population served.
What contaminants are in Snohomish's water?
The contaminants EPA monitoring detected in Snohomish include Nitrate-Nitrite, Nitrate, Fluoride, TTHM, Chloroform. 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.