Tap Water Quality Report
Tap water quality in Redmond, Washington
Tap water in Redmond, Washington receives a grade of C (71/100) from TapWaterSafety.org. It's served by REDMOND WATER SYSTEM CITY OF. The most significant water quality concerns are: PFAS contamination; Haloacetic acids (HAA9) significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in Redmond's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving Redmond.
PFAS contamination
Severe concernPerfluorooctane sulfonate (PFOS) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 22.8 ppb, 380x above the EWG health guideline of 0.06 ppb.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 23.2 ppb, 232x above the EWG health guideline of 0.1 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 25.3 ppb, 169x above the EWG health guideline of 0.15 ppb.
EPA compliance record
Official U.S. EPA records for REDMOND WATER SYSTEM CITY OF (system ID WA5371650) for the last 3 years. Checked 2026-10-07.
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Recommended filters for Redmond
Filters matched to the specific contaminants in Redmond's water supply.
Filter certified for PFOA/PFOS (NSF/ANSI 53 or 58)
$180-$750Reverse osmosis and some carbon block filters reduce PFAS. Look for certification to NSF/ANSI 53 or 58 for PFOA/PFOS.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
All contaminants detected in Redmond's tap water
Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Haloacetic acids (HAA9) Disinfection byproduct |
22.8 ppb | 0.06 | — | — | — | — | — | 380× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
23.2 ppb | 0.1 | 60.0 | 60 | — | — | — | 232× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
25.3 ppb | 0.15 | 80.0 | 100 | — | — | — | 169× over |
| Trichloroacetic acid Disinfection byproduct |
12.5 ppb | 0.1 | — | — | — | — | — | 125× over |
| Chloroform Disinfection byproduct |
22.3 ppb | 0.4 | — | — | — | — | — | 56× over |
| Dichloroacetic acid Disinfection byproduct |
9.78 ppb | 0.2 | — | — | — | — | — | 49× over |
| Bromodichloromethane Disinfection byproduct |
2.09 ppb | 0.06 | — | — | — | — | — | 35× over |
| Bromochloroacetic acid Disinfection byproduct |
0.32 ppb | 0.02 | — | — | — | — | — | 16× over |
| Dibromoacetic acid Disinfection byproduct |
0.176 ppb | 0.03 | — | — | — | — | — | 5.9× over |
| Dibromochloromethane Disinfection byproduct |
0.524 ppb | 0.1 | — | — | — | — | — | 5.2× over |
| Nitrate Inorganic |
0.707 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 5.1× over |
| Nitrate and nitrite Inorganic |
0.707 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 5.1× over |
| Chromium (hexavalent) Heavy metal |
0.0988 ppb | 0.02 | — | — | — | — | — | 4.9× over |
| Perfluorooctane sulfonate (PFOS) PFAS |
0.5 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | 1.7× over |
| Chlorate Disinfection byproduct |
43.6 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Bromoform Disinfection byproduct |
0.0907 ppb | 0.5 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
4.57 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Vanadium Other |
0.616 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
0.725 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
0.84 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.0652 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Lithium Other |
1.3 ppb | — | — | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines, California OEHHA PHGs, EWG Tap Water Database.
Treatment plant contact info
For service issues, water quality concerns, or to request a Consumer Confidence Report from REDMOND WATER SYSTEM CITY OF.