Sundquist Sunnyslope Domestic

What EPA’s and Washington’s records show in this utility’s water: nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.

Serves: 196 people
Connections: 1
Water source: Groundwater
Based in: Yakima, WA
County: Yakima
Owner: Private
Hardness: Soft

The short answer

Nothing in EPA’s and Washington’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, plus lead and copper, not everything. No health-based violations on file since 2016.

What was found

Fluoride, nitrate, arsenic, chromium (total) and uranium: Washington’s own results, samples taken from June 2, 2020 to June 4, 2026, with EPA’s 2012 to 2019 file for earlier years.

Below EPA’s limits2

Fluoride

Forms or is added in treatment

Below EPA’s limits

1.2ppm

Highest yearly average, 2022

Averaged by year, the highest was 1.2 ppm, in 2022, below EPA’s legal limit of 4.0 ppm. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.5 ppm, in 2013.

What handles it

NSF/ANSI 58 look for “Fluoride Reduction”
NSF/ANSI 53 look for “Fluoride”

Nitrate

Comes from the source

Below EPA’s limits

0.7ppm

Highest sample; found in 6 of 7

2026, one sample: 0.3 ppm

The highest sample, in 2023, was 0.7 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its one sample was 0.3 ppm.

What handles it

NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”

4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.

Arsenic
Chromium (total)
Lead
Uranium

Hardness

Soft, 28 mg/L (1.6 grains per gallon), at its one sampling point, in 2022.

Hardness is calcium and magnesium. EPA sets no limit for it: it shows up as scale on fixtures and in water heaters, and as soap that won’t lather. USGS calls water above 60 mg/L moderately hard, above 120 hard and above 180 very hard.

Softeners compared at 1.6 grains per gallon, salt included Softener or salt-free conditioner?Washington water hardness, utility by utility

Violations since 2016

No health-based violations on file with EPA since 2016. There are 2 monitoring or reporting violations: a sample missed, late or not reported.

What this report can’t tell you

Everything else. Fluoride, nitrate, arsenic, chromium (total) and uranium results here are Washington’s own from 2020 on, with EPA’s national file for 2012 to 2019. Sundquist Sunnyslope Domestic’s own annual report, which it must send you every year, has the contaminants this page does not show.
Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.
What it means for your health. This page reports what the records show and EPA’s limits and goals; it is not medical advice. If you are worried about a health effect, talk to a doctor or your local health department.
Anything after the latest data. SDWIS data is from 2026 Q3; UCMR 5 didn’t sample this utility; Washington’s results run from June 2, 2020 to June 4, 2026.

Testing your own tap

Sundquist Sunnyslope Domestic’s results are for the water it sends out. What your own service line, solder and fixtures add shows up only in a test of your tap, by a lab Washington certifies.

No lab Washington certifies is within 75 miles of the area Sundquist Sunnyslope Domestic serves on the state’s list. Some take samples by mail; the state’s page lists them all.

All 84 certified labs for Washington