What was found in ZIP 98027
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 |
|---|---|---|---|
| Fluoride | 910 µg/L 23% of the EPA limit 4000 µg/L Highest in the ZIP: KING COUNTY WATER DISTRICT NO 90 · 20,100 people · 2016 | 1/2 | SYR4 |
| Nitrate | 655.5 µg/L 6.6% of the EPA limit 10000 µg/L Main supplier: ISSAQUAH WATER SYSTEM · 43,584 people · 2019 | 1/2 | SYR4 |
| Nitrate-Nitrite | 535 µg/L 5.4% of the EPA limit 10000 µg/L Main supplier: ISSAQUAH WATER SYSTEM · 43,584 people · 2016 | 1/2 | SYR4 |
| TTHM | 49.44 µg/L 62% of the EPA limit 80 µg/L Main supplier: ISSAQUAH WATER SYSTEM · 43,584 people · 2019 | 2/2 | SYR4 |
| Chloroform | 46.44 µg/L No EPA limit set Main supplier: ISSAQUAH WATER SYSTEM · 43,584 people · 2019 | 2/2 | SYR4 |
| Total Haloacetic Acids (HAA5) | 37.87 µg/L 63% of the EPA limit 60 µg/L Main supplier: ISSAQUAH WATER SYSTEM · 43,584 people · 2019 | 2/2 | SYR4 |
| Trichloroacetic Acid | 23.775 µg/L No EPA limit set Main supplier: ISSAQUAH WATER SYSTEM · 43,584 people · 2019 | 2/2 | SYR4 |
| Dichloroacetic Acid | 17.14 µg/L No EPA limit set Main supplier: ISSAQUAH WATER SYSTEM · 43,584 people · 2019 | 2/2 | SYR4 |
| Barium | 11.95 µg/L 0.6% of the EPA limit 2000 µg/L Main supplier: ISSAQUAH WATER SYSTEM · 43,584 people · 2016 | 1/2 | SYR4 |
| Arsenic | 8.1 µg/L 81% of the EPA limit 10 µg/L Main supplier: ISSAQUAH WATER SYSTEM · 43,584 people · 2016 | 2/2 | SYR4 |
| Copper | 5 µg/L 0.4% of the EPA limit 1300 µg/L Main supplier: ISSAQUAH WATER SYSTEM · 43,584 people · 2016 | 1/2 | SYR4 |
| Monochloroacetic Acid | 3.305 µg/L No EPA limit set Main supplier: ISSAQUAH WATER SYSTEM · 43,584 people · 2019
Highest in the ZIP: 3.698 µg/L — KING COUNTY WATER DISTRICT NO 90 · 20,100 people · 2019 | 2/2 | SYR4 |
| Bromodichloromethane | 3.2 µg/L No EPA limit set Main supplier: ISSAQUAH WATER SYSTEM · 43,584 people · 2019
Highest in the ZIP: 3.225 µg/L — KING COUNTY WATER DISTRICT NO 90 · 20,100 people · 2019 | 2/2 | SYR4 |
| Dibromochloromethane | 2.48 µg/L No EPA limit set Main supplier: ISSAQUAH WATER SYSTEM · 43,584 people · 2019 | 2/2 | SYR4 |
| Dibromoacetic Acid | 1.0276 µg/L No EPA limit set Highest in the ZIP: KING COUNTY WATER DISTRICT NO 90 · 20,100 people · 2019 | 1/2 | SYR4 |
| Bromoform | 0.5000 µg/L No EPA limit set Main supplier: ISSAQUAH WATER SYSTEM · 43,584 people · 2019 | 1/2 | SYR4 |
| Lead | 0.0010 mg/L 6.7% of the EPA limit 0.0150 mg/L Main supplier: ISSAQUAH WATER SYSTEM · 43,584 people · 2022
Highest in the ZIP: 0.0012 mg/L — KING COUNTY WATER DISTRICT NO 90 · 20,100 people · 2025 | 2/2 | 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.
Water suppliers serving ZIP 98027
| Supplier | State | Population served |
|---|---|---|
| ISSAQUAH WATER SYSTEM | WA | 43,584 |
| KING COUNTY WATER DISTRICT NO 90 | WA | 20,100 |
Frequently asked questions about ZIP 98027 tap water
Is the tap water in ZIP 98027 safe to drink?
EPA testing detected 17 contaminants across the water suppliers serving ZIP 98027. 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 98027?
2 public water suppliers report EPA drinking-water monitoring for ZIP 98027. Each is listed above with its population served.
What contaminants are in ZIP 98027's water?
EPA monitoring detected Fluoride, Nitrate, Nitrate-Nitrite, TTHM, Chloroform, and others across this ZIP's suppliers. The full list with levels and sources is above.