Tap Water Quality Report
Tap water quality in Kennewick, Washington
Tap water in Kennewick, Washington receives a grade of F (47/100) from TapWaterSafety.org. It's served by KENNEWICK CITY OF. 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. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in Kennewick's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving Kennewick.
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.
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.
Recommended filters for Kennewick
Filters matched to the specific contaminants in Kennewick'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.
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 Kennewick'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 |
|---|---|---|---|---|---|---|---|---|
| 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, 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 KENNEWICK CITY OF.