Tap Water Quality Report
Tap water quality in OLYMPIA, Washington
Tap water in OLYMPIA, Washington receives a grade of D (66/100) from TapWaterSafety.org. It's served by OLYMPIA CITY OF. The most significant water quality concerns are: PFAS contamination; Haloacetic acids (HAA9) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; Arsenic significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in OLYMPIA's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving OLYMPIA.
PFAS contamination
Severe concernPerfluorooctanoic acid (PFOA), Perfluorooctane 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 4.23 ppb, 70x above the EWG health guideline of 0.06 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 8.22 ppb, 55x above the EWG health guideline of 0.15 ppb.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 0.2 ppb, 50x above the EWG health guideline of 0.004 ppb.
EPA compliance record
Official U.S. EPA records for OLYMPIA CITY OF (system ID WA5363450) for the last 3 years. Checked 2026-10-07.
| Rule | Type | Since | Status |
|---|---|---|---|
| Consumer Confidence Rule | Other (e.g. public notice) | 07/01/2025 | Resolved |
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 OLYMPIA
Filters matched to the specific contaminants in OLYMPIA'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.
Reverse osmosis certified for arsenic (NSF/ANSI 58)
$429-$599Reverse osmosis certified under NSF/ANSI 58 for arsenic is the most reliable home option.
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 OLYMPIA'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 |
4.23 ppb | 0.06 | — | — | — | — | — | 70× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
8.22 ppb | 0.15 | 80.0 | 100 | — | — | — | 55× over |
| Arsenic Heavy metal |
0.2 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 50× over |
| Bromodichloromethane Disinfection byproduct |
2.15 ppb | 0.06 | — | — | — | — | — | 36× over |
| Bromochloroacetic acid Disinfection byproduct |
0.6 ppb | 0.02 | — | — | — | — | — | 30× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
2.6 ppb | 0.1 | 60.0 | 60 | — | — | — | 26× over |
| Dibromochloromethane Disinfection byproduct |
1.18 ppb | 0.1 | — | — | — | — | — | 12× over |
| Dichloroacetic acid Disinfection byproduct |
2.0 ppb | 0.2 | — | — | — | — | — | 10× over |
| Chromium (hexavalent) Heavy metal |
0.197 ppb | 0.02 | — | — | — | — | — | 9.9× over |
| Nitrate and nitrite Inorganic |
1.38 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 9.9× over |
| Chloroform Disinfection byproduct |
3.52 ppb | 0.4 | — | — | — | — | — | 8.8× over |
| Nitrate Inorganic |
0.944 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 6.7× over |
| Trichloroacetic acid Disinfection byproduct |
0.6 ppb | 0.1 | — | — | — | — | — | 6.0× over |
| Perfluorooctanoic acid (PFOA) PFAS |
0.358 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | 4.0× over |
| Perfluorooctane sulfonate (PFOS) PFAS |
0.483 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | 1.6× over |
| Manganese Heavy metal |
38.3 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Vanadium Other |
0.543 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Barium Heavy metal |
2.88 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
0.758 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
0.333 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluoropentanoic Acid (PFPeA) PFAS |
0.275 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.059 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.07 ppm | — | 4.0 | 1.5 | 1.5 | — | — | 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 OLYMPIA CITY OF.