Tap Water Quality Report
Tap water quality in Redmond, Washington
Tap water in Redmond, Washington receives a grade of D (61/100) 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.
Recommended filters for Redmond
Filters matched to the specific contaminants in Redmond's water supply.
Reverse Osmosis or NSF P473 certified carbon
$80-$750Activated carbon and RO are the only technologies proven to remove PFAS at certified levels.
Carbon block (NSF/ANSI 42 + 53)
$40-$750Activated carbon is highly effective for disinfection byproducts like TTHM and HAA5.
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.