Houston’s drinking water comes from City of Houston (EPA system TX1010013), which draws surface water from a river, lake or reservoir and treats it before distribution for about 2,970,543 people. EPA’s records associate 512 sizeable community systems with Houston; City of Houston is the main one, and it is the system this page examines in depth. This page translates that system’s official EPA record — lead and copper results, violation history, and what the data does and does not say — into plain English.
This page is built entirely from the U.S. EPA’s Safe Drinking Water Information System (SDWIS), the same records state regulators use. We did not test Houston’s water, and system-level data describes the utility’s water as a whole — not what comes out of one specific home’s tap. Where the record is silent, we say so rather than guess.
Key takeaways
- City of Houston supplies Houston (Surface water); it serves about 2,970,543 people across its service area.
- City of Houston’s most recent reported 90th-percentile lead result is 5 ppb, below the EPA action level of 15 ppb.
- 1 health-based violation in the last 10 years — details below, with dates and current status.
- EPA does not track hardness. If you’re shopping for a softener, test first and size from a real grains-per-gallon number.
The water system serving Houston
City of Houston is the community water system the EPA associates with Houston, Texas. It reports a population served of about 2,970,543. It is flagged in EPA’s data as a wholesale supplier: it treats water and sells it on to local systems, which deliver it to homes. The record below is the wholesaler’s — your own system’s sampling can differ.
| System | EPA ID | People served | Source water | Role |
|---|---|---|---|---|
| City of Houston | TX1010013 | 2,970,543 | Surface water | Main system · wholesale supplier |
| Clear Lake City Water Authority | TX1010056 | 89,702 | Purchased surface water | Also serves the area · wholesale supplier |
| City of Houston Ud 5 – Kingwood | TX1010348 | 80,073 | Groundwater | Also serves the area · wholesale supplier |
| Harris County Mud 165 | TX1012187 | 40,503 | Purchased surface water | Also serves the area · wholesale supplier |
| Northwest Harris County Mud 5 | TX1010884 | 25,425 | Purchased surface water | Also serves the area · wholesale supplier |
| Bridgestone Mud | TX1011550 | 24,528 | Purchased surface water | Also serves the area · wholesale supplier |
EPA’s records associate 728 further systems with the Houston area beyond the ones above — neighbourhood districts, subdivisions and mobile-home parks among them. If your water bill names a different system, that name — not the city name — is the record to check.
Not sure which system serves your address? Run your ZIP code through our What’s In My Water? lookup — it resolves the systems EPA lists for your ZIP and shows the same records in full.
Lead and copper
Lead: City of Houston’s most recent reported 90th-percentile lead result is 5 ppb, below the EPA action level of 15 ppb.
Read those numbers carefully: a 90th percentile is a system-wide statistic from a sample of homes, not a test of your tap. Lead in drinking water comes mostly from a home’s own plumbing — service lines, solder and fixtures — so two houses on the same street can test very differently. Homes built before 1986 carry the highest risk, whatever the system average says.
Violation history — the last 10 years
EPA records show 1 health-based violation for City of Houston in the last 10 years. Health-based means the serious kind — here is what it was:
- a regulated contaminant (EPA code 0300) — a required treatment technique step was not followed. Began May 2025; returned to compliance July 2025.
The recent paperwork record is clean too: no monitoring or reporting items in the last 5 years.
What this means for your home
System data sets the background; your home’s plumbing writes the foreground. In practice:
- Lead deserves action here. A system 90th percentile of 5 ppb means sampled homes in this system do pick up lead. If your home predates 1986, a filter certified to NSF/ANSI 53 for lead — or a reverse osmosis system (NSF/ANSI 58) — is the standard fix; see our water filter guides and certified filter picks for what the certifications actually cover.
- Taste and smell: surface-water systems disinfect with chlorine or chloramine, which is most of what people taste. A basic carbon filter (NSF/ANSI 42) handles it; our chloramine vs chlorine explainer helps you tell which one your water has.
- Hardness is not in this record — by design. The EPA doesn’t track it, so nobody can honestly tell you your grains-per-gallon from this page. Scale on fixtures and shower doors is a hint, not a measurement. Test (strips are a start; a lab test is better — see how to test your water at home), then size any softener with our softener sizing calculator and the softener hub.
- On a private well instead of city water? None of this system’s record applies to your tap — start with our well water hub for the test-first approach.
Water quality in nearby cities
San Antonio, TX · Dallas, TX · New York, NY
This guide is one of our per-city water reports — see the full list on the Water Quality hub, alongside our contaminant explainers and testing guides.
Frequently asked questions
Is Houston water safe to drink?
The honest answer is: largely yes today, with real entries on its record. City of Houston has 1 health-based violation in the last 10 years (detailed in the violation section above); all of them now show as returned to compliance. A returned-to-compliance violation is history, not a current failure — and for lead, {lead_clause}. EPA data describes the system as a whole, not your tap; lead usually comes from a home’s own plumbing, so a certified home test is the only way to know your exact water.
Where does Houston get its drinking water?
City of Houston is the community water system the EPA associates with Houston. It draws surface water from a river, lake or reservoir and treats it before distribution and serves about 2,970,543 people across its service area (EPA system ID TX1010013). 511 other sizeable systems also report serving parts of Houston — they are listed in the table above.
What is the lead level in Houston’s water?
City of Houston’s most recent reported 90th-percentile lead result is 5 ppb, below the EPA action level of 15 ppb. That figure is a system statistic from sampled homes, not a test of your tap — your own plumbing decides your exposure, and a certified home test is the only way to know it.
Has Houston’s water system had violations?
Yes — 1 health-based violation in the last 10 years, listed with dates and status in the violation section above. All of them show as returned to compliance in EPA’s record.
Do I need a water filter in Houston?
The clearest reason to filter in Houston is lead from home plumbing, given the system’s 90th-percentile result. A filter certified to NSF/ANSI 53 for lead (or reverse osmosis, NSF/ANSI 58) is the standard answer. For everything else, match the tool to a measured problem — hardness included — rather than buying for a list of fears.
Source: U.S. EPA SDWIS via Envirofacts, retrieved November 12, 2026. System-level data describes the utility’s water, not any individual tap. If your water bill names a different system, that system’s record is the one that applies to you.