What was found in ZIP 98029
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 | 2233.5 µg/L 22% of the EPA limit 10000 µg/L Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2019 | 2/3 | SYR4 |
| Nitrate-Nitrite | 1728.4999999999998 µg/L 17% of the EPA limit 10000 µg/L Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2018 | 3/3 | SYR4 |
| Fluoride | 800 µg/L 20% of the EPA limit 4000 µg/L Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2018 | 1/3 | SYR4 |
| Copper | 30.9 µg/L 2.4% of the EPA limit 1300 µg/L Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2018
Highest in the ZIP: 288.4999999999998 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2018 | 3/3 | SYR4 |
| TTHM | 45.30999999999999 µg/L 57% of the EPA limit 80 µg/L Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2019
Highest in the ZIP: 122.27499999999999 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 3/3 | SYR4 |
| Chloroform | 41.47499999999999 µg/L No EPA limit set Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2019
Highest in the ZIP: 94.645 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 3/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 38.38199999999999 µg/L 64% of the EPA limit 60 µg/L Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2019
Highest in the ZIP: 62.71 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 3/3 | SYR4 |
| Barium | 50.8 µg/L 2.5% of the EPA limit 2000 µg/L Highest in the ZIP: BRYAN CO. RWS & SWMD #2 · 6,270 people · 2013 | 2/3 | SYR4 |
| Trichloroacetic Acid | 22.109999999999996 µg/L No EPA limit set Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2019
Highest in the ZIP: 36.03 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 3/3 | SYR4 |
| Dichloroacetic Acid | 17.969999999999995 µg/L No EPA limit set Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2019
Highest in the ZIP: 30.354999999999997 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 3/3 | SYR4 |
| Bromodichloromethane | 3.7 µg/L No EPA limit set Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2019
Highest in the ZIP: 24.055 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 3/3 | SYR4 |
| Lead | 3.9 µg/L 26% of the EPA limit 15 µg/L Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2018
Highest in the ZIP: 18.391999999999996 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2018 | 2/3 | SYR4 |
| Dibromochloromethane | 1.9819999999999998 µg/L No EPA limit set Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2019
Highest in the ZIP: 8.8385 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 3/3 | SYR4 |
| Monochloroacetic Acid | 3.2955 µg/L No EPA limit set Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2019
Highest in the ZIP: 8.368 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 3/3 | SYR4 |
| Arsenic | 6.39 µg/L 64% of the EPA limit 10 µg/L Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2018
Highest in the ZIP: 8.099999999999998 µg/L — ISSAQUAH WATER SYSTEM · 43,584 people · 2016 | 2/3 | SYR4 |
| Monobromoacetic Acid | 3.6494999999999993 µg/L No EPA limit set Highest in the ZIP: BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 1/3 | SYR4 |
| Dibromoacetic Acid | 0.6603 µg/L No EPA limit set Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2019
Highest in the ZIP: 2.612 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 2/3 | SYR4 |
| Gross Beta Particle Activity | 2.0540000000000003 pCi/L No EPA limit set Highest in the ZIP: BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 1/3 | SYR4 |
| Bromoform | 0.6475 µg/L No EPA limit set Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2019
Highest in the ZIP: 1.274 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 3/3 | SYR4 |
| Combined Radium (-226 And -228) | 1.095 pCi/L 22% of the EPA limit 5 pCi/L Highest in the ZIP: BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 1/3 | SYR4 |
| 2,4-D | 0.9000 µg/L 1.3% of the EPA limit 70 µg/L Highest in the ZIP: BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 1/3 | SYR4 |
| Cadmium | 0.2000 µg/L 4% of the EPA limit 5 µg/L Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2018 | 1/3 | SYR4 |
| Asbestos | 0.1150 MFL 1.6% of the EPA limit 7 MFL Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2017 | 1/3 | SYR4 |
| PFHXS | 0.0165 µg/L No EPA limit set Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2024 | 1/3 | UCMR-5 |
| PFOS | 0.0111 µg/L No EPA limit set Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2024 | 1/3 | UCMR-5 |
| PFBS | 0.0088 µg/L No EPA limit set Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2024 | 1/3 | UCMR-5 |
| Pfhxa | 0.0043 µg/L No EPA limit set Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2024 | 1/3 | UCMR-5 |
| Pfpes | 0.0041 µg/L No EPA limit set Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2024 | 1/3 | UCMR-5 |
| Pfpea | 0.0039 µg/L No EPA limit set Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2024 | 1/3 | UCMR-5 |
| Lead | 0.0017 mg/L 11% of the EPA limit 0.0150 mg/L Main supplier: SAMMAMISH PLATEAU WATER & SEWER · 79,362 people · 2025 | 3/3 | 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.
Water suppliers serving ZIP 98029
| Supplier | State | Population served |
|---|---|---|
| SAMMAMISH PLATEAU WATER & SEWER | WA | 79,362 |
| ISSAQUAH WATER SYSTEM | WA | 43,584 |
| BRYAN CO. RWS & SWMD #2 | OK | 6,270 |
Frequently asked questions about ZIP 98029 tap water
Is the tap water in ZIP 98029 safe to drink?
EPA testing detected 30 contaminants across the water suppliers serving ZIP 98029. 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 98029?
3 public water suppliers report EPA drinking-water monitoring for ZIP 98029. Each is listed above with its population served.
What contaminants are in ZIP 98029's water?
EPA monitoring detected Nitrate, Nitrate-Nitrite, Fluoride, Copper, TTHM, and others across this ZIP's suppliers. The full list with levels and sources is above.