What was found in ZIP 98053
The level at this ZIP's main supplier, the highest level anywhere in it, the EPA limit for each, and where the figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate | 1710 µg/L 17% of the EPA limit 10000 µg/L Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2019
Highest in the ZIP: 2233.5 µg/L — SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2019 | 3/4 | SYR4 |
| Nitrate-Nitrite | 1710 µg/L 17% of the EPA limit 10000 µg/L Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2019
Highest in the ZIP: 1728.5 µg/L — SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2018 | 3/4 | SYR4 |
| Fluoride | 830 µg/L 21% of the EPA limit 4000 µg/L Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2017 | 2/4 | SYR4 |
| TTHM | 40.48 µg/L 51% of the EPA limit 80 µg/L Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2019
Highest in the ZIP: 45.31 µg/L — SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2019 | 3/4 | SYR4 |
| Total Haloacetic Acids (HAA5) | 43.78 µg/L 73% of the EPA limit 60 µg/L Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2019 | 3/4 | SYR4 |
| Chloroform | 38.18 µg/L No EPA limit set Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2019
Highest in the ZIP: 41.475 µg/L — SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2019 | 3/4 | SYR4 |
| Copper | 34 µg/L 2.6% of the EPA limit 1300 µg/L Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2017 | 2/4 | SYR4 |
| Trichloroacetic Acid | 23.485 µg/L No EPA limit set Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2019
Highest in the ZIP: 25.32 µg/L — WOODINVILLE WATER DISTRICT · 66,699 people · 2019 | 3/4 | SYR4 |
| Dichloroacetic Acid | 20.25 µg/L No EPA limit set Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2019 | 3/4 | SYR4 |
| Lithium | 13 µg/L No EPA limit set Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2024 | 1/4 | UCMR-5 |
| Arsenic | 1.8 µg/L 18% of the EPA limit 10 µg/L Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2017
Highest in the ZIP: 6.39 µg/L — SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2018 | 3/4 | SYR4 |
| Bromodichloromethane | 6.1025 µg/L No EPA limit set Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2019 | 3/4 | SYR4 |
| Barium | 5 µg/L 0.3% of the EPA limit 2000 µg/L Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2017 | 1/4 | SYR4 |
| Dibromochloromethane | 4.29 µg/L No EPA limit set Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2019 | 3/4 | SYR4 |
| Monochloroacetic Acid | 4.25 µg/L No EPA limit set Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2019 | 3/4 | SYR4 |
| Lead | 3.9 µg/L 26% of the EPA limit 15 µg/L Highest in the ZIP: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2018 | 1/4 | SYR4 |
| Chromium | 2 µg/L 2% of the EPA limit 100 µg/L Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2017 | 1/4 | SYR4 |
| Gross Beta Particle Activity | 1.575 pCi/L No EPA limit set Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2016 | 1/4 | SYR4 |
| Dibromoacetic Acid | 1.444 µg/L No EPA limit set Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2019 | 2/4 | SYR4 |
| Tetrachloroethylene | 1.05 µg/L 21% of the EPA limit 5 µg/L Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2019 | 1/4 | SYR4 |
| Bromoform | 1.0164 µg/L No EPA limit set Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2019 | 2/4 | SYR4 |
| Cadmium | 0.2000 µg/L 4% of the EPA limit 5 µg/L Highest in the ZIP: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2018 | 1/4 | SYR4 |
| Asbestos | 0.1150 MFL 1.6% of the EPA limit 7 MFL Highest in the ZIP: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2017 | 1/4 | SYR4 |
| PFHXS | 0.0165 µg/L No EPA limit set Highest in the ZIP: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2024 | 1/4 | UCMR-5 |
| PFOS | 0.0050 µg/L No EPA limit set Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2024
Highest in the ZIP: 0.0111 µg/L — SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2024 | 2/4 | UCMR-5 |
| PFBS | 0.0050 µg/L No EPA limit set Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2024
Highest in the ZIP: 0.0088 µg/L — SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2024 | 2/4 | UCMR-5 |
| Lead | 0.0020 mg/L 13% of the EPA limit 0.0150 mg/L Main supplier: REDMOND WATER SYSTEM CITY OF · 163,335 people · 2024
Highest in the ZIP: 0.0058 mg/L — UNION HILL WATER ASSOCIATION INC · 8,720 people · 2025 | 3/4 | LCR |
| Pfhxa | 0.0043 µg/L No EPA limit set Highest in the ZIP: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2024 | 1/4 | UCMR-5 |
| Pfpes | 0.0041 µg/L No EPA limit set Highest in the ZIP: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2024 | 1/4 | UCMR-5 |
| Pfpea | 0.0039 µg/L No EPA limit set Highest in the ZIP: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2024 | 1/4 | 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.
Water suppliers serving ZIP 98053
| Supplier | State | Population served |
|---|---|---|
| REDMOND WATER SYSTEM CITY OF | WA | 163,335 |
| SAMMAMISH PLATEAU WATER & SEWER | WA | 79,362 |
| WOODINVILLE WATER DISTRICT | WA | 66,699 |
| UNION HILL WATER ASSOCIATION INC | WA | 8,720 |
Frequently asked questions about ZIP 98053 tap water
Is the tap water in ZIP 98053 safe to drink?
EPA testing detected 30 contaminants across the water suppliers serving ZIP 98053. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and your utility's annual Consumer Confidence Report for the official status.
Which water suppliers serve ZIP 98053?
4 public water suppliers report EPA drinking-water monitoring for ZIP 98053. Each is listed above with its population served.
What contaminants are in ZIP 98053's water?
EPA monitoring detected Nitrate, Nitrate-Nitrite, Fluoride, TTHM, Total Haloacetic Acids (HAA5), and others across this ZIP's suppliers. The full list with levels and sources is above.