We read 13 results from Redmond Water System City of’s 2025 water quality report. No results over a legal limit; 4 above a health goal or guideline.
Serves about 147,897 people · Water system ID WA5371650 · Read the district’s 2025 report (opens in a new tab)
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Results from the 2025 report
Each number is copied from the district’s report and links to the page it’s printed on. Where the report lists several plants, wells or purchased water, the highest is shown.
| Contaminant | Result | Health goal | Legal limit | What it means |
|---|---|---|---|---|
| Arsenicaverage · range 0.2 to 0.4 · Tolt supply · 2025 report, page 6 | 0.3 ppb | 0.004 ppb | 10 ppb | Above the health goal75x the health goal |
| Lead90th percentile of 50 homes tested, 0 over the action level · sampled 2024 · Customer taps (50 homes) · 2025 report, page 12 | 3.5 ppb | 0.2 ppb | 15 ppb (action level) | Above the health goal18x the health goal |
| PFOA (a PFAS)highest measured · range ND to 2.03 · Groundwater wells (highest well) · 2025 report, page 9 | 2.03 ppt | 0.007 ppt | 4 ppt from 2029 | Above the health goal290x the health goal |
| PFOS (a PFAS)average · range 2.27 to 5.62 · Groundwater wells (highest well) · 2025 report, page 9 | 5.12 ppt | 1 ppt | 4 ppt from 2029 | Above the federal limit that takes effect in 20291.3x the 4 ppt federal limit that takes effect in 2029Not a violation yet: EPA's 4 ppt limit is final, but water systems don't have to meet it until 2029. |
| Bariumaverage · range 0.0011 to 0.0015 · printed as 1.3 ppb · Tolt supply · 2025 report, page 6 | 0.0013 ppm | 2 ppm | 2 ppm | Below the health goal |
| Chlorineaverage · range 0.22 to 1.57 · Tolt supply, highest of 2 sources · 2025 report, page 6 | 0.89 ppm | None set | 4 ppm | Below the legal limit |
| Copper90th percentile of 50 homes tested, 0 over the action level · sampled 2024 · Customer taps (50 homes) · 2025 report, page 12 | 0.19 ppm | 0.3 ppm | 1.3 ppm (action level) | Below the health goal |
| Disinfection byproducts (HAA5)average · range 19.4 to 30.3 · Tolt supply · 2025 report, page 6 | 27.7 ppb | None set | 60 ppb | Below the legal limit |
| Disinfection byproducts (TTHM)average · range 23.8 to 33.3 · Tolt supply · 2025 report, page 6 | 30.5 ppb | None set | 80 ppb | Below the legal limit |
| Fluorideaverage · range 0.6 to 0.75 · Tolt supply, highest of 2 sources · 2025 report, page 6 | 0.7 ppm | 1 ppm | 4 ppm | Below the health goal |
| Nitrate (as N)average · range ND to 1.06 · Groundwater wells · 2025 report, page 9 | 0.6 ppm | 10 ppm | 10 ppm | Below the health goal |
| Turbidity (cloudiness)average · range 0.02 to 0.28 · Tolt supply · 2025 report, page 6 | 0.04 NTU | None set | 1 NTU | Below the legal limit |
| PFBS (a PFAS)average · range ND to 5.06 · Groundwater wells (highest well) · 2025 report, page 9 | 4.77 ppt | None set | None | No health limit |
Utility results describe the whole system, measured where water enters the pipes, not your tap. Your home’s plumbing can add lead or copper.
EPA testing for PFAS and lithium
EPA’s own nationwide testing (UCMR 5) found these in Redmond Water System City of’s water between Nov 2023 and Aug 2024. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.
- PFOS5 pptFound in 1 of 10 samples · highest resultAbove the federal limit that takes effect in 2029 (4 ppt)
- PFBS5 pptFound in 2 of 10 samples · highest resultNo federal limit in force for this one
- Lithium13 ppbFound in 1 of 10 samples · highest resultAbove EPA’s health reference level of 10 ppb (a guide, not a legal limit)
Source: EPA UCMR 5 occurrence data. The highest single result is shown; one high sample doesn’t mean every glass is that high.
What you can do
Nothing here is an emergency notice: if the district has a violation, it must tell customers directly. If you’d like to lower these at your tap, these are the treatments that remove them, and the catalog shows the models certified for each. Ranking is by certified removal; commissions never change the order.
Lead
Found: Lead
What removes it: Certified carbon block or RO.
PFAS ("forever chemicals")
Found: PFOA (a PFAS), PFOS (a PFAS), PFOS (EPA testing)
What removes it: Reverse osmosis.
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