City of Katy
EPA ID: TX1010017 · 25,253 people served · 7 ZIP codes
EPA compliance records for City of Katy show 1 unresolved violation — findings that remain open and are tracked at the federal level, covering a service territory of approximately 25,253 people.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for City of Katy Source: EPA SDWIS service area boundaries.
Service area boundary — Grade A
Service Area Demographics
The City of Katy serves a community with a median household income of $105,607 and an estimated 412,434 residents across its service area.
Environmental Justice Note: 40% of the population in this service area is classified as disadvantaged under EPA's EJScreen criteria. Communities with higher disadvantaged populations often face disproportionate environmental and health burdens, including aging water infrastructure and limited resources for remediation.
💧 Where Does Your Water Come From?
City of Katy's water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
About 1% of homes in Waller County, Texas rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Wastewater Proximity Note: This service area ranks in the 61th percentile nationally for proximity to wastewater discharge points.
Infrastructure Risk
Detected Contaminants
How City of Katy compares to EPA limits
What This Means For You
Total Coliform at 1 presence exceeds the EPA maximum of presence.
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 19 detections recorded. 2 exceed federal EPA limits (4 ppt for PFOA/PFOS).
Comparable Water Systems
Similar-sized systems in Texas
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
City of Katy (EPA ID: TX1010017) is a community water system in Texas that serves approximately 25,253 people from groundwater sources.
This system provides water to 7 ZIP codes across 2 communities.
Average Home Safety Score: A (85/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| June 24, 2025 | Total Coliform | Monitoring | Unresolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Total Coliform | Microbiological | 1 | No |
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
| ZIP Code | Lead Level | Exceeds Limit | Sample Date |
|---|---|---|---|
| 77449 | 0.0018 mg/L | No | N/A |
| 77491 | 0.0018 mg/L | No | N/A |
| 77492 | 0.0018 mg/L | No | N/A |
| 77493 | 0.0018 mg/L | No | N/A |
| 77494 | 0.0018 mg/L | No | N/A |
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 3 (Low Risk)
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
Coverage: 3 ZIP codes confirmed via EPA Community Water System Service Area Boundaries v3 plus 4 additional ZIPs inferred from SDWIS registry data. The EPA-confirmed set is the most reliable; SDWIS-inferred entries may be narrower than the real deployment area.
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for City of Katy (TX1010017) on EPA.gov.
Frequently Asked Questions
Is City of Katy water safe to drink?
City of Katy has only monitoring/reporting violations, which are procedural in nature. The system meets federal health-based standards.
How many people does City of Katy serve?
City of Katy serves approximately 25,253 people across 7 ZIP codes in Texas.
Where does City of Katy get its water?
The primary water source is groundwater.
Federal UCMR5 PFAS Monitoring: Tested Clean
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). No PFAS compounds were detected.
Current MCL reflects the lowest state-enforceable limit (NYS 10 ppt for PFOA/PFOS, effective August 2020). The federal final MCL of 4 ppt for PFOA/PFOS (EPA April 2024 rule) is not enforceable until April 2029. Detections above 4 ppt but below 10 ppt are below current MCL but above the future federal limit.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.
Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026
ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.
Frequently Asked Questions
What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
City of Katy (EPA ID: TX1010017) — request the latest Consumer Confidence Report or ask about specific contaminants.