Water Quality Report · Updated May 12, 2026
OLYMPIA CITY OF
OLYMPIA CITY OF delivers tap water graded D (56/100) by TapWaterSafety.org. The utility serves approximately 126,966 residents in OLYMPIA, Washington using groundwater. 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.
Is OLYMPIA tap water safe to drink?
OLYMPIA CITY OF delivers tap water that earns a grade of D (56/100) from TapWaterSafety.org — a below-average rating, with multiple concerns including pfas contamination.
The utility serves 126,966 residents in OLYMPIA, drawing from groundwater.
Public testing data identifies 15 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Arsenic, Bromodichloromethane, Bromochloroacetic acid, Haloacetic acids (HAA5), Dibromochloromethane, Dichloroacetic acid, Chromium (hexavalent), Nitrate and nitrite, Chloroform, Nitrate, Trichloroacetic acid, Perfluorooctanoic acid (PFOA), Perfluorooctane sulfonate (PFOS). For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
Quick actions for OLYMPIA residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for OLYMPIA CITY OF.
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.
Contact OLYMPIA CITY OF
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for OLYMPIA
Filters matched to the specific contaminants in this 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.
Reverse Osmosis
$249-$750Arsenic is most effectively removed by reverse osmosis. Some specialized adsorptive filters also work.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
Score breakdown
This utility's overall score of 56/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). 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 (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
OLYMPIA CITY OF service area
This water system serves 1 community in Thurston County, Washington. Click any city for its dedicated tap water quality page.
Find the right filter for OLYMPIA water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.