Costa Mesa, CA Water Quality Report

Is Costa Mesa tap water safe? See PFAS and lead contamination levels for Costa Mesa, California. Compare to EPA limits and get filter recommendations.

Quick Answers

Is Costa Mesa tap water safe to drink? Costa Mesa tap water meets most federal EPA limits, but PFAS compounds have been detected at an average of 30.11 ppt across 3 compounds. A certified pitcher filter or reverse osmosis system is recommended for sensitive populations.

What contaminants are in Costa Mesa water? Top PFAS compounds detected in Costa Mesa water: lithium (67.2 ppt), PFBA (0.01 ppt), PFPeA (0 ppt). See the full table for all monitored contaminants and comparison to EPA limits.

What filter should I use in Costa Mesa? Reverse osmosis removes 90%+ of PFAS, lead, and arsenic. NSF-53 certified pitcher and faucet filters (ZeroWater, Clearly Filtered, LifeStraw) work for smaller households. Skip standard Brita filters for PFAS removal.

Costa Mesa Water Quality Summary

EPA testing has detected PFAS "forever chemicals" in Costa Mesa drinking water. Recent monitoring found a peak level of 67.2 ppt across 2 water systems, representing an average of 30.11 ppt across 3 detected compounds.

Contamination Level: MODERATE – Moderate contamination – PFAS detected at meaningful levels; filtration recommended.

Top Detected Compounds

  • lithium: 67.2 ppt (exceeds EPA 4 ppt limit for PFOA/PFOS)
  • PFBA: 0.01 ppt
  • PFPeA: 0 ppt

Lead in Costa Mesa Water

EPA Lead and Copper Rule testing has recorded 14 lead samples for Costa Mesa water systems, with a 90th-percentile high of 0 mg/L (within the EPA 0.015 mg/L action level). There is no safe level of lead for children; if your home was built before 1986, a certified NSF/ANSI 53 lead-removal filter is recommended.

EPA Violations in Costa Mesa

Costa Mesa public water systems have 35 health-based EPA Safe Drinking Water Act violations on record, including Arsenic, 1028, Dichloroacetic Acid. Health-based violations mean a contaminant exceeded its federal limit or required treatment was not applied.

About the Data

These figures come from the EPA's Unregulated Contaminant Monitoring Rule 5 (UCMR5) testing program, 2023-2025. UCMR5 is the most comprehensive national drinking water survey in US history, covering 66,000+ public water systems. Population of Costa Mesa: approximately 113,408.

ZIP Codes Served

92626, 92627, 92628

What Costa Mesa Residents Should Do

  1. Enter your exact ZIP code at knowyourexposure.com for address-level data
  2. Install an NSF/ANSI 58 reverse osmosis filter (removes 94-99% of PFAS)
  3. If you're in a high-exposure group (pregnant, young children), consider a PFAS home test kit
  4. Review your utility's Consumer Confidence Report (CCR) annually