Concord, CA Water Quality (ZIP 94520)

Quick Answers

Is ZIP 94520 tap water safe to drink? No PFAS above thresholds is reported for 94520 in current EPA data. Lead risk from older plumbing is a separate question; the results below cover the regulated contaminants tested for this system.

What filter should I use in 94520? A reverse osmosis system (NSF/ANSI 58) removes 90%+ of PFAS, lead, and arsenic. For smaller households, an NSF-53 certified pitcher (Clearly Filtered, ZeroWater) works. Standard Brita cartridges are not certified for PFAS.

ZIP 94520 Water Quality Summary

The public water system serving ZIP 94520 (Concord, CA) is not currently reported as having detected PFAS in recent EPA UCMR5 testing, though other regulated contaminants appear in the data below.

Contamination Level: NONE – No PFAS detected in recent testing for the systems serving this ZIP code.

Lead in ZIP 94520 Water

EPA Lead and Copper Rule testing recorded 14 lead samples for the systems serving 94520, with a 90th-percentile high of 0.057 mg/L (above the EPA 0.015 mg/L action level). There is no safe level of lead for children; homes built before 1986 should use a certified NSF/ANSI 53 lead filter.

About the Data

Source: EPA UCMR5 monitoring (2023-2025), Lead and Copper Rule samples, and SDWIS violation records tied to the water system that serves 94520 in Concord, CA.

Beyond water: other exposures in Concord, CA

Drinking water is one exposure route. These are the other federal datasets that cover ZIP 94520 and Contra Costa County, CA.

Radon risk in Contra Costa County, CA

The EPA places Contra Costa County, CA in Zone 2 - a moderate-risk category, with a predicted average indoor radon level between 2 and 4 pCi/L. Zone maps predict the radon potential of an area from geology and existing indoor readings - they do not describe any individual home. Radon is the leading cause of lung cancer among people who have never smoked, and the only way to know your own level is a test kit.

Lead paint risk in Contra Costa County, CA

Census figures show 54% of homes in Contra Costa County, CA were built before 1980, and 11% before 1950. Lead-based paint was banned for residential use in 1978, so older housing stock is the strongest available proxy for lead-paint exposure. This is a statistic about the county's housing, not a test of any particular property - if your home predates 1980, a lead swab test is the way to check.

Air quality in Contra Costa County, CA

Modelled annual fine-particle pollution (PM2.5) for Contra Costa County, CA averages 8.4 µg/m³, within the EPA's annual PM2.5 standard of 9 µg/m³. PM2.5 is the pollution fraction small enough to reach deep into the lungs. These are CDC modelled estimates for the county as a whole, not a reading taken at this ZIP code.

Superfund sites near 94520

There is 1 EPA Superfund (National Priorities List) site within about five miles of 94520: Concord Naval Weapons Station (about 4.3 miles). Distances are measured from the ZIP code's geographic centre, so the distance from a specific address will differ. Proximity to a listed site is a fact about location - it is not itself evidence of exposure.

Industrial releases near 94520

EPA Toxics Release Inventory data for 2023 records 8 reporting facilities within about five miles of 94520, together reporting roughly 1,119,396 pounds of on-site chemical releases that year. TRI covers facilities above federal reporting thresholds, so smaller sources are not included, and a reported release is not the same as a measured concentration in air or water.