EPA data as of Oct 2026 · page updated 2026-10-29

Home hazard report for 78521 — Brownsville, TX

ZIP 78521 is served by Brownsville Public Utilities Board: no health-based violations since 2016, latest lead result 0 ppb, PFAS 9.2 ppt. Cameron County is in EPA radon zone 3.

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Where ZIP 78521 is

Dashed: ZIP area · blue: utility service area · scroll or pinch to zoom
ZIP code areaZIP center Water utility service area PFOA/PFOS ≥ 4 ppt Lead > 15 ppb 5+ violations Superfund site (active) proposed cleaned up Circles: other water systems flagged nearby; size = people served. Tap any symbol for details.

Drinking water: Brownsville Public Utilities Board

EPA IDTX0310001
People served201,249
Sourcesurface water (rivers, lakes)
Connections62,849

Health-based violations

No health-based violations reported since 2016.

Full record for Brownsville Public Utilities Board →

Other systems overlapping this ZIP: El Jardin WSC.

Lead

Jan 20220 ppb
Jan 20190 ppb
Jul 20180 ppb
Jan 20181.4 ppb
Jan 20132 ppb
Jan 20121.8 ppb
Jan 20101.8 ppb
Jan 20061.9 ppb

90th-percentile lead per sampling round (90% of the homes sampled were at or below this level). Black line: EPA’s 15 ppb action level; under the Lead and Copper Rule Improvements the action level becomes 10 ppb from 2027.

PFAS (“forever chemicals”)

CompoundHighest resultSamples with detectionEPA limit
PFBA9.3 ppt7 of 8—
PFOS9.2 ppt7 of 84 ppt MCL
PFHxA8 ppt8 of 8—
PFPeA7.6 ppt8 of 8—
PFOA4.7 ppt1 of 84 ppt MCL
PFHxS4.4 ppt8 of 8—
PFHpA4.1 ppt2 of 8—
PFDAnot detected0 of 8—
HFPO-DA (GenX)not detected0 of 8—
PFNAnot detected0 of 8—
PFBSnot detected0 of 8—

EPA Fifth Unregulated Contaminant Monitoring Rule (UCMR 5), samples 2023–2025; ppt = parts per trillion (ng/L). The 4.0 ppt maximum contaminant levels for PFOA and PFOS were set by EPA in 2024; water systems have until the end of the decade to comply.

Radon in Cameron County

EPA radon zone 3 — low potential. Predicted average under 2 pCi/L — but any home can have high radon, so EPA still recommends a test.

Radon is a colorless, odorless radioactive gas from soil and rock, and the leading cause of lung cancer among non-smokers. EPA recommends fixing a home at 4 pCi/L or above and considering it from 2 pCi/L. A short-term test kit costs about $15–30. How radon zones work →

Natural hazard risk

FEMA rates the overall natural-hazard risk of this neighborhood (census tract) as Relatively High, with relatively moderate social vulnerability and very low community resilience.

HurricaneVery High
Cold waveRelatively High
Coastal floodingRelatively Moderate
HailRelatively Moderate
Heat waveRelatively Moderate
Ice stormRelatively Moderate
WildfireRelatively Moderate
Winter weatherRelatively Moderate
DroughtRelatively Low
LightningRelatively Low
Riverine floodingRelatively Low
Strong windRelatively Low
TornadoRelatively Low
EarthquakeVery Low
LandslideVery Low

FEMA National Risk Index (December 2025): expected annual losses from each hazard combined with social vulnerability and community resilience, rated relative to all U.S. census tracts. Hazards not listed are not applicable here. It describes the area, not a single building; flood insurance maps (FEMA FIRMs) decide flood-insurance requirements.

Live conditions: river gauges and flood levels · tornado warnings · wildfire detections · earthquakes — our sister maps, updated from NOAA, USGS and NASA every few minutes.

Superfund sites nearby

No site on EPA’s Superfund National Priorities List lies within 10 miles of the center of this ZIP code.

EPA Superfund National Priorities List (NPL): the country’s most serious known hazardous-waste sites, each with an EPA cleanup record (linked). Distance is measured from the ZIP center to the site’s reference point; being near a site does not by itself mean exposure — EPA site pages describe what was found and how it is being cleaned up.

Buying a home in Brownsville? See the 2026 conforming, FHA and jumbo loan limits for Cameron County →

What this is — and isn’t. These are records your water utility and state reported to the EPA, and the EPA’s radon map for your county. They describe the system and the area, not the water from your own tap or the air in your home. For that, read your utility’s annual Consumer Confidence Report and test: lead and radon tests are inexpensive.

Questions about 78521

Who supplies drinking water to ZIP 78521?

Brownsville Public Utilities Board (EPA ID TX0310001), a surface water (rivers, lakes) system serving about 201,249 people.

Is there lead in Brownsville, TX tap water?

The utility’s latest 90th-percentile lead result (Jan 2022) was 0 ppb; EPA’s action level is 15 ppb, falling to 10 ppb from 2027. Lead mostly comes from service lines and home plumbing, so the only way to know your tap is to test it.

Does Brownsville, TX water have PFAS?

Highest PFOA or PFOS result in EPA’s 2023–2025 testing was at or above 4.0 ppt, EPA’s 2024 maximum contaminant level for each. 7 PFAS compounds detected.

Has the water system in 78521 had violations?

No health-based violations reported since 2016.

What natural hazards affect ZIP 78521?

FEMA’s National Risk Index rates the overall natural-hazard risk here as Relatively High; the highest-rated hazards are hurricane (very high), cold wave (relatively high), coastal flooding (relatively moderate).

Are there Superfund sites near 78521?

No active Superfund site within 10 miles of the ZIP center.

Is radon a problem in Cameron County?

Cameron County is in EPA radon zone 3 (low potential). Predicted average under 2 pCi/L — but any home can have high radon, so EPA still recommends a test.