El Toro Water District water quality

Updated 2026-10-22 · California · Affiliate disclosure

We read 14 results from El Toro Water District’s 2025 water quality report. No results over a legal limit; 3 above a health goal or guideline.

Serves about 51,800 people · Water system ID CA3010079 · 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.

ContaminantResultHealth goalLegal limitWhat it means
Bromateaverage · range ND to 8.4 · listed as a violation in the report · MWD Diemer plant · 2025 report, page 52.4 ppb0.1 ppb10 ppbAbove the health goal24x the health goal
Total dissolved solidsaverage · range 465 to 625 · listed as a violation in the report · MWD Diemer plant · 2025 report, page 5545 ppm—500 ppm guidelineAbove the guideline1.1x the guideline (taste, odor or stains; not a health limit)
Uraniumaverage · range ND to 4.47 · listed as a violation in the report · printed as 1 pCi/L · MWD Diemer plant · 2025 report, page 51.49 ppb0.6 ppb30 ppbAbove the health goal2.5x the health goal
Bariumaverage · range 0.13 to 0.13 · listed as a violation in the report · MWD Diemer plant · 2025 report, page 50.13 ppm2 ppm2 ppmBelow the health goal
Chlorideaverage · range 84 to 99 · listed as a violation in the report · MWD Diemer plant · 2025 report, page 592 ppm—250 ppm guidelineWithin the guideline
Chlorineaverage · range 0.3 to 2.66 · listed as a violation in the report · Distribution system · 2025 report, page 71.77 ppmNone set4 ppmBelow the legal limit
Copper90th percentile of 34 homes tested, 0 over the action level · listed as a violation in the report · sampled 2023 · Customer taps · 2025 report, page 70.08 ppm0.3 ppm1.3 ppm (action level)Below the health goal
Disinfection byproducts (HAA5)highest running annual average · range 12 to 32 · listed as a violation in the report · Distribution system · 2025 report, page 723 ppbNone set60 ppbBelow the legal limit
Disinfection byproducts (TTHM)highest running annual average · range 20 to 44 · listed as a violation in the report · Distribution system · 2025 report, page 740 ppbNone set80 ppbBelow the legal limit
Fluorideaverage · range 0.6 to 0.8 · listed as a violation in the report · MWD Diemer plant · 2025 report, page 50.7 ppm1 ppm2 ppmBelow the health goal
Lead90th percentile of 34 homes tested, 0 over the action level · listed as a violation in the report · sampled 2023 · Customer taps · 2025 report, page 7Not detected0.2 ppb15 ppb (action level)Not detected
Sulfateaverage · range 146 to 218 · listed as a violation in the report · MWD Diemer plant · 2025 report, page 5182 ppm—250 ppm guidelineWithin the guideline
Lithiumaverage · range 44 to 55 · sampled 2024 · MWD Diemer plant · 2025 report, page 545 ppbNone setNoneNo health limit
Sodiumaverage · range 78 to 97 · MWD Diemer plant · 2025 report, page 588 ppmNone setNoneNo 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 El Toro Water District’s water between Apr 2023 and Jan 2024. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.

  • Lithium45 ppbFound in 12 of 16 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.

Disinfection byproducts

Found: Bromate

What removes it: Carbon block.

See filters that remove it

Salty taste / high TDS

Found: Total dissolved solids

What removes it: Reverse osmosis.

See filters that remove it

Radium and uranium

Found: Uranium

What removes it: Reverse osmosis.

See filters that remove it

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