Costa Mesa, California: Is the Tap Water Safe to Drink?
2026 EPA water quality data for 4 community water systems serving 110,576+ residents. See violations, PFAS results, lead test results, and safety grades — free.
Is Costa Mesa Tap Water Safe to Drink?
Based on the latest EPA data, Costa Mesa tap water meets all federal drinking water standards. All 4 tested systems have received a safety grade of A or B, with no active health-based violations.
Costa Mesa Water Quality Overview
Costa Mesa, California is served by 4 community water systems providing water to approximately 110,576 residents. These systems draw from groundwater (2), surface water purchased (1), surface water (1) sources. Costa Mesa water systems have recorded 55 health-based violations in their history, though none are currently active. Including monitoring and reporting violations, there are 92 total violations on record.
Find Your Water System
Search by ZIP code to find your exact water provider and see its full EPA report.
All 4 water systems in Costa Mesa
Looking for water quality data across the whole state? See our full California tap water safety report covering California’s EPA-regulated water systems.
Costa Mesa Drinking Water: Frequently Asked Questions
Is Costa Mesa, California tap water safe to drink?
Based on the latest EPA data, Costa Mesa tap water meets all federal drinking water standards. All 4 tested systems have received a safety grade of A or B, with no active health-based violations.
How many water utilities serve Costa Mesa, California?
4 community water systems serve Costa Mesa, California, providing water to approximately 110,576 people. Different neighborhoods may be served by different utilities. Enter your ZIP code at the top to find your specific provider.
Does Costa Mesa 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 Costa Mesa drinking water?
EPA violation records for Costa Mesa 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 Costa Mesa?
Enter your Costa Mesa 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).