Lead in San Dimas, CA Drinking Water
Lead data for San Dimas, California · 156,943 residents · 1 ZIP code
Over the past reporting period, water systems in San Dimas, California have recorded Lead at detectable concentrations in EPA compliance samples.
Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-05-14
Lead in San Dimas Tap Water
Lead has been detected in San Dimas, California drinking water at a maximum level of 3.2 ppb — below the EPA action level of 15 ppb (action level).
This analysis covers 156,943 residents across 1 ZIP code in San Dimas.
San Dimas's overall water quality grade is A (95/100).
Is Lead in San Dimas Water Safe?
Lead was detected in San Dimas water but currently falls within EPA limits. However, some health organizations argue the EPA action level may not be protective enough — the CDC states there is no safe level of lead for children.
If you are concerned, a reverse osmosis or nsf 53 carbon block filter can reduce lead levels further.
Lead Levels by ZIP Code
| ZIP Code | Lead Level | EPA Limit | Status |
|---|---|---|---|
| 91773 | 3.2 ppb | 15 ppb (action level) | OK |
Average lead level across San Dimas: 3.2 ppb
Health Effects of Lead
- Brain development delays and reduced IQ in children
- Behavioral problems and learning disabilities
- High blood pressure and kidney damage in adults
- Increased risk of premature birth in pregnant women
Health risk severity: High. Governed by the Lead and Copper Rule Revisions (LCRR/LCRI).
How Lead Gets Into Drinking Water
- Corrosion of lead service lines (pipes connecting water main to home)
- Lead solder in copper plumbing joints (pre-1986 homes)
- Brass fixtures and faucets manufactured before 2014
- Stagnant water that sits in lead-containing pipes overnight
What to Do About Lead in San Dimas Water
- Install an NSF 53 or NSF 58 certified filter at kitchen sink
- Run cold water for 30 seconds before using for drinking or cooking
- Use cold water only for cooking and preparing formula
- Consider whole-home reverse osmosis if lead service line is present
Look for filters certified under NSF 53 / NSF 58 for lead removal.