City of Paso Robles Water Division Water Quality (California) – 2025 Report Results

We read 25 results from City of Paso Robles Water Division’s 2025 water quality report. No results over a legal limit; 7 above a health goal or guideline.

Serves about 31,176 people · Water system ID CA4010007 · 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 ND to 4.8 · listed as a violation in the report · Sources · 2025 report, page 4	1.95 ppb	0.004 ppb	10 ppb	Above the health goal488x the health goal
Chromium-6average · range ND to 2 · Sources · 2025 report, page 5	0.49 ppb	0.02 ppb	10 ppb	Above the health goal25x the health goal
Copper90th percentile of 30 homes tested, 0 over the action level · listed as a violation in the report · Customer taps · 2025 report, page 4	0.41 ppm	0.3 ppm	1.3 ppm (action level)	Above the health goal1.4x the health goal
Gross alpha (radioactivity)average · range ND to 7.2 · listed as a violation in the report · Sources · 2025 report, page 4	1.61 pCi/L	0 pCi/L	15 pCi/L	Above the health goalThe health goal is zero
PFOA (a PFAS)average · range ND to 1.4 · Sources · 2025 report, page 5	0.16 ppt	0.007 ppt	4 ppt from 2029	Above the health goal23x the health goal
Tetrachloroethylene (PCE)average · range ND to 1.1 · listed as a violation in the report · Sources · 2025 report, page 4	0.07 ppb	0.06 ppb	5 ppb	Above the health goal1.2x the health goal
Thalliumaverage · range ND to 1.8 · listed as a violation in the report · Sources · 2025 report, page 4	0.13 ppb	0.1 ppb	2 ppb	Above the health goal1.3x the health goal
1,1-Dichloroethyleneaverage · range ND to 0.28 · listed as a violation in the report · Sources · 2025 report, page 4	0.02 ppb	7 ppb	7 ppb	Below the health goal
Aluminumaverage · range ND to 0.09 · listed as a violation in the report · Sources · 2025 report, page 4	0.02 ppm	—	0.2 ppm guideline	Within the guideline
Bariumaverage · range ND to 0.33 · listed as a violation in the report · Sources · 2025 report, page 4	0.07 ppm	2 ppm	2 ppm	Below the health goal
Chlorideaverage · range 7.1 to 230 · listed as a violation in the report · Sources · 2025 report, page 5	48.2 ppm	—	250 ppm guideline	Within the guideline
Chlorineaverage · range 0.2 to 2.2 · listed as a violation in the report · Distribution system · 2025 report, page 4	1.2 ppm	None set	4 ppm	Below the legal limit
Disinfection byproducts (HAA5)as reported · range 2.1 to 18.2 · listed as a violation in the report · Distribution system · 2025 report, page 4	7.08 ppb	None set	60 ppb	Below the legal limit
Disinfection byproducts (TTHM)as reported · range 5.7 to 57.8 · listed as a violation in the report · Distribution system · 2025 report, page 4	18.7 ppb	None set	80 ppb	Below the legal limit
Fluorideaverage · range ND to 0.4 · listed as a violation in the report · Sources · 2025 report, page 4	0.19 ppm	1 ppm	2 ppm	Below the health goal
Ironaverage · range ND to 0.23 · listed as a violation in the report · printed as 30.41 ppb · Sources · 2025 report, page 5	0.03 ppm	—	0.3 ppm guideline	Within the guideline
Nitrate (as N)average · range ND to 3.4 · listed as a violation in the report · Sources · 2025 report, page 4	1.35 ppm	10 ppm	10 ppm	Below the health goal
PFHxS (a PFAS)average · range ND to 4.03 · Sources · 2025 report, page 5	0.24 ppt	None set	10 ppt from 2029	Below the legal limit
Seleniumaverage · range ND to 20 · listed as a violation in the report · Sources · 2025 report, page 4	6.26 ppb	30 ppb	50 ppb	Below the health goal
Sulfateaverage · range 19 to 140 · listed as a violation in the report · Sources · 2025 report, page 5	72.3 ppm	—	250 ppm guideline	Within the guideline
Total dissolved solidsaverage · range 180 to 760 · listed as a violation in the report · Sources · 2025 report, page 5	424 ppm	—	500 ppm guideline	Within the guideline
Turbidity (cloudiness)highest measured · range 0.01 to 0.09 · listed as a violation in the report · Treatment plant · 2025 report, page 4	0.09 NTU	None set	1 NTU	Below the legal limit
Lithiumaverage · range ND to 46.2 · Sources · 2025 report, page 5	14.3 ppb	None set	None	No health limit
PFBS (a PFAS)average · range ND to 4.33 · Sources · 2025 report, page 5	0.39 ppt	None set	None	No health limit
Sodiumaverage · range 12 to 140 · Sources · 2025 report, page 5	42.4 ppm	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 City of Paso Robles Water Division’s water between Dec 2024 and Oct 2025. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.

PFOA6.3 pptFound in 2 of 26 samples · highest resultAbove the federal limit that takes effect in 2029 (4 ppt)
PFHxS5.2 pptFound in 5 of 26 samples · highest resultNo federal limit in force for this one
PFBS8.1 pptFound in 5 of 26 samples · highest resultNo federal limit in force for this one
Lithium49.2 ppbFound in 21 of 26 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.