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Tap water quality report

Union Gap, WA

EPA monitoring detected 12 contaminants across the 1 water supplier serving Union Gap. 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
6,433
people served
12
contaminants found
Washington rankings Lead in Washington PFAS in Washington

What was found in Union Gap'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
1740 µg/L 17%
of the EPA limit 10000 µg/L
Main supplier: UNION GAP WATER · 6,433 people · 2019
1/1 SYR4
Nitrate-Nitrite
1740 µg/L 17%
of the EPA limit 10000 µg/L
Main supplier: UNION GAP WATER · 6,433 people · 2019
1/1 SYR4
Fluoride
266.5 µg/L 6.7%
of the EPA limit 4000 µg/L
Main supplier: UNION GAP WATER · 6,433 people · 2019
1/1 SYR4
Barium
37.496 µg/L 1.9%
of the EPA limit 2000 µg/L
Main supplier: UNION GAP WATER · 6,433 people · 2019
1/1 SYR4
Copper
19.068 µg/L 1.5%
of the EPA limit 1300 µg/L
Main supplier: UNION GAP WATER · 6,433 people · 2019
1/1 SYR4
Lithium
9.78 µg/L
No EPA limit set
Main supplier: UNION GAP WATER · 6,433 people · 2024
1/1 UCMR-5
Arsenic
5.84 µg/L 58%
of the EPA limit 10 µg/L
Main supplier: UNION GAP WATER · 6,433 people · 2019
1/1 SYR4
Lead
4.255 µg/L 28%
of the EPA limit 15 µg/L
Main supplier: UNION GAP WATER · 6,433 people · 2019
1/1 SYR4
Chromium
1.638 µg/L 1.6%
of the EPA limit 100 µg/L
Main supplier: UNION GAP WATER · 6,433 people · 2019
1/1 SYR4
Selenium
0.8900 µg/L 1.8%
of the EPA limit 50 µg/L
Main supplier: UNION GAP WATER · 6,433 people · 2019
1/1 SYR4
Thallium, Total
0.3950 µg/L 20%
of the EPA limit 2 µg/L
Main supplier: UNION GAP WATER · 6,433 people · 2019
1/1 SYR4
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
Main supplier: UNION GAP WATER · 6,433 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 Union Gap

SupplierPopulation served
UNION GAP WATER 6,433

Frequently asked questions about Union Gap tap water

Is Union Gap tap water safe to drink?

EPA testing detected 12 contaminants in the water serving Union Gap. 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 Union Gap?

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

What contaminants are in Union Gap's water?

The contaminants EPA monitoring detected in Union Gap include Nitrate, Nitrate-Nitrite, Fluoride, Barium, Copper. 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.