Yuma County · Arizona · EPA SDWIS 2026Q2
San Luis Water Quality
What's in San Luis's water
Total Trihalomethanes (TTHM)
Violation on record
Legal limit80 ppb
1 EPA violation on record (most recent 2021). TTHM form when chlorine used to disinfect water reacts with natural organic matter. Long-term exposure has been linked to increased cancer risk and to harm in pregnancy. Levels often rise in warmer months and in systems with more organic material.
Water hardness
very hard
San Luis's water is very hard. Hardness isn't a health risk, but it drives scale on fixtures and water heaters, shortens appliance life, and leaves skin and hair dry.
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SAN LUIS CITY OF
- Population served
- 39,705
- PWSID
- AZ0414005
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