B
74

US Water Score: B

Houston, TX 77056

Harris County · Population served: 2,970,543 · Data updated July 2026

Service-area evidence: EPA service-area records associate the listed system with this ZIP. Boundaries may still overlap or change.

Water Systems Serving This Area

🏔
CITY OF HOUSTON
Surface water · Pop. 2,970,543
PWSID: TX1010013
🌊
HARRIS COUNTY MUD 489
Groundwater · Pop. 10,476
PWSID: TX1013628
🏔
MONTGOMERY COUNTY MUD 95
Surface water · Pop. 6,435
PWSID: TX1700779
🏔
HARRIS COUNTY MUD 400 - EAST
Surface water · Pop. 6,066
PWSID: TX1013416
🏔
HARRIS COUNTY MUD 344
Surface water · Pop. 4,518
PWSID: TX1012974

Contaminants Detected

ContaminantDetected LevelEPA MCLHealth GuidelineStatus
Lead
15.8
15 ppb 1 ppb

PFAS / Forever Chemicals

4 detected Below comparison values

UCMR5 occurrence results are screening information, not a finding of regulatory compliance or noncompliance. PFAS rules and compliance dates are evolving.

CompoundLevelEPA MCLHealth GuidelineStatus
6:2 FTS42.6 pptNo standardNo federal MCL shown
PFBA10.6 pptNo standard500 pptNo federal MCL shown
PFPeA6.7 pptNo standardNo federal MCL shown
PFHxA5.1 pptNo standard400 pptNo federal MCL shown

Violation History (Last 5 Years)

81Total (5yr)
4Health-Based
34Major

Water Quality Summary

Understanding Your Water in Houston

Tap water quality in Houston, Texas (77056) receives an overall grade of B (Good) with a score of 74 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is 6 points below the Texas state average of 80. The area is served by 86 water systems providing water to approximately 2,970,543 people, using groundwater and surface water sources. PFAS testing detected 4 compounds, all below the EPA final MCL values used for comparison. Over the past 5 years, water systems here have accumulated 81 violations, including 4 health-based violations.

Your Score 74/100 B
vs State 6 pts below Texas avg (80)
vs National 1 pts below national avg (75)

What a Grade B Means

A score of 74/100 means Houston, TX performs well in the US Water Score model, with only minor system-level concerns. Residents should still review their utility's Consumer Confidence Report for official compliance information and household-specific context.

Groundwater: drawn from underground aquifers via wells
Surface water: sourced from rivers, lakes, or reservoirs

Health Information

What These Contaminants Mean for You

⚠️

Lead in Your Water

Lead is a toxic metal that can leach from aging pipes and plumbing fixtures.

Health Effects

Even low levels of lead exposure can cause developmental delays in children, kidney damage, and cardiovascular effects in adults. The EPA action level is 15 ppb, but health experts recommend no safe level of lead in drinking water.

Common Sources

Lead enters water primarily through corrosion of lead service lines, lead solder, and brass fixtures — especially in homes built before 1986.

What You Can Do

If lead is detected above 1 ppb, consider using a certified lead-removal filter (NSF/ANSI 53) for drinking and cooking water. Run cold water for 30 seconds before use if water has been sitting in pipes.

Common Questions

Frequently Asked Questions

Based on public water-system records, Houston, Texas receives an internal US Water Score grade of B (Good) with a score of 74/100. This indicates relatively few system-level concerns in our model, but it is not an EPA safety rating and does not guarantee tap conditions inside individual homes.

ZIP code 77056 is served by 86 water systems using groundwater, surface water sources, providing water to approximately 2,970,543 people. Multiple source types mean your water may come from a blend of surface and underground sources.

Lead levels in the public-system record for Houston, Texas are 15.8 ppb, above the currently applicable EPA action level of 15 ppb. EPA's Lead and Copper Rule Improvements lower that action level to 10 ppb when the new requirements take effect. This system-level result does not measure an individual tap; consider a certified lead-removal filter and independent tap testing.

4 PFAS compounds were detected in water serving Houston, Texas, with reported values below the EPA final MCL values used by this site. This comparison is informational: federal compliance timelines and the status of some PFAS standards are still evolving. Activated carbon or reverse osmosis filters can reduce some PFAS when appropriately certified and maintained.

Water systems serving Houston, Texas have received 81 violations in the last 5 years, including 4 health-based violations. Violations can range from paperwork issues (monitoring & reporting) to serious health-based violations where contaminant levels exceeded safe limits. Review the violation details above for specifics.

Based on detected contaminants (lead, PFAS), residents in Houston, Texas should consider: Reverse osmosis (RO) system — most effective for PFAS, lead, and other contaminants. Always look for filters with NSF/ANSI certification for the specific contaminants you want to remove.

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