Water Quality Report · Updated October 07, 2026
KENNEWICK CITY OF
KENNEWICK CITY OF delivers tap water graded F (47/100) by TapWaterSafety.org. The utility serves approximately 118,164 residents in Kennewick, Washington using surface water. The most significant water quality concerns are: PFAS contamination; Perfluorohexane sulfonate (PFHXS) significantly above health guideline; Total PFOS and PFOA significantly above health guideline; Arsenic significantly above health guideline.
Is Kennewick tap water safe to drink?
KENNEWICK CITY OF delivers tap water that earns a grade of F (47/100) from TapWaterSafety.org — a poor rating, with significant contamination concerns and/or recent violations.
The utility serves 118,164 residents in Kennewick, drawing from surface water.
Public testing data identifies 19 contaminants in this water above EWG's health-based guidelines, including: Perfluorooctane sulfonate (PFOS), Perfluorohexane sulfonate (PFHXS), Total PFOS and PFOA, Arsenic, Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Haloacetic acids (HAA5), Bromodichloromethane, Trichloroacetic acid, Chloroform, Dibromochloromethane, Dibromoacetic acid, Dichloroacetic acid, Chromium (hexavalent), Nitrate, Perfluorooctanoic acid (PFOA), Nitrate and nitrite, Bromoform, Chlorate. 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.
EPA compliance record
Official U.S. EPA records for KENNEWICK CITY OF (system ID WA5338100) for the last 3 years. Checked 2026-10-07.
| Rule | Type | Since | Status |
|---|---|---|---|
| Stage 2 Disinfectants and Disinfection Byproducts Rule | Missed testing or reporting | 04/01/2023 | Resolved |
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Quick actions for Kennewick residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for KENNEWICK CITY OF.
PFAS contamination
Severe concernPerfluorooctane sulfonate (PFOS), Perfluorooctanoic acid (PFOA) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Perfluorohexane sulfonate (PFHXS) significantly above health guideline
Moderate concernPerfluorohexane sulfonate (PFHXS) detected at 8.67 ppt, 8673x above the EWG health guideline of 0.001 ppt.
Total PFOS and PFOA significantly above health guideline
Moderate concernTotal PFOS and PFOA detected at 9.64 ppt, 1377x above the EWG health guideline of 0.007 ppt.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 2.23 ppb, 558x above the EWG health guideline of 0.004 ppb.
Contact KENNEWICK 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 Kennewick
Filters matched to the specific contaminants in this 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.
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.
Score breakdown
This utility's overall score of 47/100 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 |
|---|---|---|---|---|---|---|---|---|
| Perfluorooctane sulfonate (PFOS) PFAS |
4.77 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | EPA violation |
| Perfluorohexane sulfonate (PFHXS) PFAS |
8.67 ppt | 0.001 | 10.0 | — | — | — | — | 8673× over |
| Total PFOS and PFOA PFAS |
9.64 ppt | 0.007 | — | 100 | 100 | 0.007 | — | 1377× over |
| Arsenic Heavy metal |
2.23 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 558× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
20.8 ppb | 0.06 | — | — | — | — | — | 347× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
34.0 ppb | 0.15 | 80.0 | 100 | — | — | — | 226× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
11.7 ppb | 0.1 | 60.0 | 60 | — | — | — | 117× over |
| Bromodichloromethane Disinfection byproduct |
6.77 ppb | 0.06 | — | — | — | — | — | 113× over |
| Trichloroacetic acid Disinfection byproduct |
6.31 ppb | 0.1 | — | — | — | — | — | 63× over |
| Chloroform Disinfection byproduct |
19.9 ppb | 0.4 | — | — | — | — | — | 50× over |
| Dibromochloromethane Disinfection byproduct |
4.69 ppb | 0.1 | — | — | — | — | — | 47× over |
| Dibromoacetic acid Disinfection byproduct |
0.859 ppb | 0.03 | — | — | — | — | — | 29× over |
| Dichloroacetic acid Disinfection byproduct |
3.52 ppb | 0.2 | — | — | — | — | — | 18× over |
| Chromium (hexavalent) Heavy metal |
0.342 ppb | 0.02 | — | — | — | — | — | 17× over |
| Nitrate Inorganic |
1.83 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 13× over |
| Perfluorooctanoic acid (PFOA) PFAS |
1.04 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | 12× over |
| Nitrate and nitrite Inorganic |
1.58 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 11× over |
| Bromoform Disinfection byproduct |
1.55 ppb | 0.5 | — | — | — | — | — | 3.1× over |
| Chlorate Disinfection byproduct |
210.4 ppb | 210.0 | — | — | — | — | — | 1.0× over |
| Perfluoropentane sulfonic acid (PFPeS) PFAS |
0.21 ppt | 1.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
3.55 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
9.75 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Barium Heavy metal |
42.8 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Molybdenum Other |
0.764 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Perfluoropentanoic Acid (PFPeA) PFAS |
4.05 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
3.66 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
3.12 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
0.0665 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Perfluorobutanoic Acid (PFBA) PFAS |
1.18 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluoroheptanoic acid (PFHPA) PFAS |
0.451 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.176 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.242 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Lithium Other |
1.17 ppb | — | — | — | — | — | — | Below guideline |
| PFOS + PFOA + PFHxS + PFNA PFAS |
18.2 ppt | — | — | 100 | 100 | 0.007 | — | 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.
KENNEWICK CITY OF service area
This water system serves 1 community in Benton County, Washington. Click any city for its dedicated tap water quality page.
Find the right filter for Kennewick water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.