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San Dimas, California: Is the Tap Water Safe to Drink?

2026 EPA water quality data for 6 community water systems serving 157,316+ residents. See violations, PFAS results, lead test results, and safety grades — free.

Is San Dimas Tap Water Safe to Drink?

San Dimas has 6 community water systems. 4 of 6 graded systems meet all EPA standards (grade A or B), while 2 have recorded violations. No active health-based violations are currently open. Check individual system reports below for specifics.

San Dimas Water Quality Overview

San Dimas, California is served by 6 community water systems providing water to approximately 157,316 residents. These systems draw from surface water purchased (4), groundwater (2) sources. San Dimas water systems have no recorded health-based violations. Including monitoring and reporting violations, there are 4 total violations on record.

6
Water Systems
0
Health Violations
4/6
Rated A or B
4
PFAS Tested
💧 Filter Guide📖 Violations Explained📄 Read Your CCR⚠ PFAS Guide

Find Your Water System

Search by ZIP code to find your exact water provider and see its full EPA report.

All 6 water systems in San Dimas

GSWC-SAN DIMAS B
SAN DIMAS, CA · 56,538 people · Surface Water Purchased 1 health violation in past 5 yrs
GSWC - CLAREMONT C
SAN DIMAS, CA · 39,730 people · Surface Water Purchased 2 health violations in past 5 yrs
GSWC-SOUTH ARCADIA C
SAN DIMAS, CA · 27,072 people · Groundwater 2 health violations in past 5 yrs
GSWC-SOUTH SAN GABRIEL A
SAN DIMAS, CA · 26,240 people · Surface Water Purchased ✓ No recent health violations
GSWC - CALIPATRIA A
SAN DIMAS, CA · 7,363 people · Surface Water Purchased ✓ No recent health violations
GOLDEN STATE WATER MORONGO DELNORTE A
SAN DIMAS, CA · 373 people · Groundwater ✓ No recent health violations

Looking for water quality data across the whole state? See our full California tap water safety report covering California’s EPA-regulated water systems.

San Dimas Drinking Water: Frequently Asked Questions

Is San Dimas, California tap water safe to drink?

San Dimas has 6 community water systems. 4 of 6 graded systems meet all EPA standards (grade A or B), while 2 have recorded violations. No active health-based violations are currently open. Check individual system reports below for specifics.

How many water utilities serve San Dimas, California?

6 community water systems serve San Dimas, California, providing water to approximately 157,316 people. Different neighborhoods may be served by different utilities. Enter your ZIP code at the top to find your specific provider.

Does San Dimas tap water have lead?

Lead in drinking water typically enters from old pipes and fixtures inside homes and buildings, not from the treatment plant. The EPA requires water systems to monitor for lead under the Lead and Copper Rule. Click any water system above to see its most recent 90th-percentile lead test results. Homes built before 1986 are most likely to have lead plumbing components.

What contaminants have been found in San Dimas drinking water?

EPA violation records for San Dimas water systems are listed on each utility's report page. Common regulated contaminants include disinfection byproducts (TTHMs, HAA5), coliform bacteria, nitrates, and lead. Click any utility above to see its full violation history going back 10 years.

How do I find out which water company serves my address in San Dimas?

Enter your San Dimas ZIP code in the search box at the top of this page. ClearWater will identify the specific water system serving your area and show you its EPA violation history, lead test results, and an overall safety grade. You can also check your water bill or your utility's annual Consumer Confidence Report (CCR).