We read 8 results from Santa Margarita Water District-Id9’s 2025 water quality report. No results over a legal limit; 1 above a health goal or guideline.
Serves about 39,684 people · Water system ID CA3010030 · 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 |
|---|---|---|---|---|
| Total dissolved solidsaverage · range 260 to 680 · listed as a violation in the report · Distribution system · 2025 report, page 4 | 503 ppm | — | 500 ppm guideline | Above the guideline1x the guideline (taste, odor or stains; not a health limit) |
| Chlorineaverage · range 1.58 to 1.99 · listed as a violation in the report · Distribution system · 2025 report, page 4 | 1.77 ppm | None set | 4 ppm | Below the legal limit |
| Copper90th percentile of 31 homes tested, 0 over the action level · listed as a violation in the report · sampled 2024 · Customer taps · 2025 report, page 4 | 0.09 ppm | 0.3 ppm | 1.3 ppm (action level) | Below the health goal |
| Disinfection byproducts (HAA5)average · range ND to 8.9 · listed as a violation in the report · Distribution system · 2025 report, page 4 | 7 ppb | None set | 60 ppb | Below the legal limit |
| Disinfection byproducts (TTHM)average · range 8.1 to 46 · listed as a violation in the report · Distribution system · 2025 report, page 4 | 32 ppb | None set | 80 ppb | Below the legal limit |
| Lead90th percentile of 31 homes tested, 0 over the action level · listed as a violation in the report · sampled 2024 · Customer taps · 2025 report, page 4 | Not detected | 0.2 ppb | 15 ppb (action level) | Not detected |
| Hardnessaverage · range 5.21 to 17 · Distribution system · 2025 report, page 4 | 12.3 gpg (210 ppm) | — | — | Very hard |
| Sodiumaverage · range 62 to 110 · Distribution system · 2025 report, page 4 | 84 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 Santa Margarita Water District-Id9’s water between Jun 2024 and Mar 2025. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.
- Lithium57.4 ppbFound in 8 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.
Salty taste / high TDS
Found: Total dissolved solids
What removes it: Reverse osmosis.
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