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WaterSafeCheck

ZIP Code 77491 Water Quality Report

Katy, TX · Waller County County

Safety Score
A

Water Safety Grade

Excellent — Meets all EPA standards

Health Violations

0

Total Violations

1

Lead Risk

N/A

Contaminants

0

About Tap Water in ZIP Code 77491

Tap water in ZIP code 77491 (Katy, TX) is among the safest in the country. Served by City of Katy, this area earned a water safety grade of A with a composite score of 97/100 — indicating full regulatory compliance and low contaminant risk across EPA monitoring periods.

Water System

City of Katy

EPA ID: TX1010017

Water Source

Ground Water

Population Served

25,253 residents

County

Waller County County, Texas

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Lead Levels in ZIP 77491

EPA action level: 15 ppb | Public health goal: 0 ppb

Lead Level: 1.8 ppb — Very Low

The 90th percentile lead level in 77491 is 1.8 ppb, well below the EPA action level of 15 ppb. While this is a reassuring result, the EPA's public health goal for lead is actually zero — no amount of lead is considered completely safe, particularly for children under 6 and pregnant women. Running your tap for 30 seconds before use and using a certified NSF/ANSI 53 filter adds an extra layer of protection.
Lead Level (90th percentile)
1.80 ppb (0.0018 mg/L)
Lead Exposure Risk Rating
Unknown
Note: Lead levels above are the 90th percentile from EPA monitoring — meaning 90% of samples were at or below this level. Even "undetected" tap water lead doesn't account for lead leaching from home plumbing. If your home was built before 1986, individual tap testing is recommended.
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Violation History

Past 5 years — EPA SDWIS data

City of Katy has recorded 1 violation, but none are health-based. Administrative or reporting violations don't directly indicate unsafe water, but they do signal gaps in documentation or monitoring procedures. 1 violation is currently unresolved — meaning the issue has not yet been formally corrected in EPA records. This is a serious concern that residents should follow up on with their water utility.

Total Violations (5 yr)
1
Health-Based Violations
0
Unresolved Violations
1
Boil Water Advisories
0
Compliance Risk
Moderate

Regulatory compliance risk is rated Moderate. City of Katy has had occasional lapses in compliance but generally meets Safe Drinking Water Act requirements.

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Contaminants Detected

Contaminants with health-based violations on record

No health-based contaminant violations are on record for ZIP code 77491. This means EPA monitoring has not found levels of regulated contaminants exceeding the Maximum Contaminant Levels (MCLs) set under the Safe Drinking Water Act — a positive indicator of water quality compliance.

⚖ Enforcement Actions

4 enforcement actions have been issued against City of Katy — a high number that reflects sustained compliance struggles. Enforcement actions escalate from administrative orders to financial penalties when utilities repeatedly fail to meet safe drinking water standards.
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Water Source & Environmental Factors

Ground Water

This system draws water from underground aquifers. Groundwater is naturally filtered through soil and rock, but can still contain naturally occurring minerals like arsenic, radium, or nitrates.

Water Source Type
Ground Water
EPA Radon Zone

Lower potential

Zone 3

EPA Radon Zone 3 — lower radon potential, though the EPA still recommends testing all homes.

🛡 What Should You Do? — ZIP 77491 Recommendations

  • ✓ Run cold water for 30 seconds each morning before use — especially if pipes are old
  • ✓ Request your annual Consumer Confidence Report from City of Katy
  • ✓ If your home was built before 1986, consider testing your own tap for lead
  • ✓ Use a pitcher filter (NSF/ANSI 42 certified) for improved taste

Frequently Asked Questions — ZIP 77491 Water Quality

Is tap water safe to drink in ZIP code 77491?+
Yes — tap water in 77491 (Katy, TX) currently meets all federal EPA standards with a water safety grade of A. No health-based violations are on record in the past 5 years. You can drink your tap water with confidence, though running the tap for 30 seconds in the morning is always a good practice.
What is the lead level in 77491 tap water?+
The 90th percentile lead level in 77491 is 1.8 ppb (parts per billion). The EPA action level is 15 ppb. This is a low level, well below the EPA action level of 15 ppb.
Who provides tap water to 77491?+
Tap water in ZIP code 77491 is provided by City of Katy (EPA ID: TX1010017). This system serves approximately 25,253 residents. You can contact them directly for Consumer Confidence Reports, current advisories, and billing information.
What is the water source for 77491?+
ZIP code 77491 is served by ground water. Groundwater systems draw from underground aquifers. While naturally filtered, groundwater can still contain naturally occurring contaminants such as arsenic, radium, or nitrates at elevated levels in some regions.
Does 77491 have any active water quality violations?+
Yes — there are currently 1 unresolved violation on record for this water system. Unresolved violations indicate issues that have not yet been formally corrected in EPA tracking systems. Contact City of Katy for the latest update.
How do I get a copy of my water quality report for 77491?+
Your water utility — City of Katy — is required by law to send you an annual Consumer Confidence Report (CCR) by July 1 each year. You can also request it directly from the utility or find it online by searching "City of Katy Consumer Confidence Report." The EPA's ECHO database also has historical compliance data.
What water filter should I use in 77491?+
The right filter depends on what contaminants are present. For lead, look for a filter certified to NSF/ANSI Standard 53. For chlorine byproducts (like THMs), NSF/ANSI 42 filters work well. For a broad range of contaminants including PFAS, look for NSF/ANSI 58 (reverse osmosis) systems. For ZIP code 77491, with a clean compliance record, a standard carbon block filter meeting NSF/ANSI 42 is a good choice for taste and as a precaution.
Is 77491 tap water safe for babies and infants?+
Infants are especially vulnerable to lead, nitrates, and microbial contaminants in drinking water. Current EPA data for 77491 shows a lead level of 1.8 ppb — below the action level, but as an extra precaution, run your tap for 30 seconds before use and consider a certified lead filter for infant formula. Always consult your pediatrician for guidance specific to your child's health.

Data Sources & Methodology

Water quality data for ZIP code 77491 is compiled from the EPA Safe Drinking Water Information System (SDWIS), EPA ECHO enforcement database, UCMR5 unregulated contaminant monitoring, and Consumer Confidence Reports filed by City of Katy. Safety scores are composite metrics derived from violation history, lead levels, enforcement actions, and infrastructure risk indicators. Data reflects a 5-year monitoring window. Last dataset update: 2024. View EPA source data →