Tap WaterIndex

← Washington

Tap water quality report

Clarkston, WA

EPA monitoring detected 10 contaminants across the 1 water supplier serving Clarkston. A detection doesn't automatically mean the water is unsafe — see the level at the main supplier for each below, with its EPA source and period.

1
water supplier
21,930
people served
10
contaminants found
Washington rankings Lead in Washington PFAS in Washington

What was found in Clarkston's water

The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Nitrate
1620 µg/L 16%
of the EPA limit 10000 µg/L
Main supplier: PUD #1 OF ASOTIN COUNTY · 21,930 people · 2019
1/1 SYR4
Lithium
43.8 µg/L
No EPA limit set
Main supplier: PUD #1 OF ASOTIN COUNTY · 21,930 people · 2025
1/1 UCMR-5
TTHM
8.368 µg/L 10%
of the EPA limit 80 µg/L
Main supplier: PUD #1 OF ASOTIN COUNTY · 21,930 people · 2019
1/1 SYR4
Bromoform
4.962 µg/L
No EPA limit set
Main supplier: PUD #1 OF ASOTIN COUNTY · 21,930 people · 2019
1/1 SYR4
Dibromochloromethane
2.6695 µg/L
No EPA limit set
Main supplier: PUD #1 OF ASOTIN COUNTY · 21,930 people · 2019
1/1 SYR4
Dibromoacetic Acid
1.1065 µg/L
No EPA limit set
Main supplier: PUD #1 OF ASOTIN COUNTY · 21,930 people · 2019
1/1 SYR4
Total Haloacetic Acids (HAA5)
1.1065 µg/L 1.8%
of the EPA limit 60 µg/L
Main supplier: PUD #1 OF ASOTIN COUNTY · 21,930 people · 2019
1/1 SYR4
Bromodichloromethane
0.8440 µg/L
No EPA limit set
Main supplier: PUD #1 OF ASOTIN COUNTY · 21,930 people · 2019
1/1 SYR4
Chloroform
0.2600 µg/L
No EPA limit set
Main supplier: PUD #1 OF ASOTIN COUNTY · 21,930 people · 2019
1/1 SYR4
Lead
0.0035 mg/L 23%
of the EPA limit 0.0150 mg/L
Main supplier: PUD #1 OF ASOTIN COUNTY · 21,930 people · 2023
1/1 LCR
Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of the system's samples — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving Clarkston

SupplierPopulation served
PUD #1 OF ASOTIN COUNTY 21,930

Frequently asked questions about Clarkston tap water

Is Clarkston tap water safe to drink?

EPA testing detected 10 contaminants in the water serving Clarkston. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve Clarkston?

1 public water supplier report drinking-water monitoring for Clarkston, Washington to the EPA. Each is listed above with its population served.

What contaminants are in Clarkston's water?

The contaminants EPA monitoring detected in Clarkston include Nitrate, Lithium, TTHM, Bromoform, Dibromochloromethane. The full list, with the level at the main supplier and the data source, is in the table above.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.