Markham, TX Water Safety: 82/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
For households in Markham, TX water data shows a consistently above-average safety picture.
How Markham Compares
Data: EPA SDWIS Last verified: 2026-06-03
Markham Water: The Quick Version
- Homes built before 1986: 76% — older plumbing may contain lead solder.
- Estimated remediation: $1,800 per household.
- CDC health risk index: 14.48 — above typical levels.
Water Systems Serving Markham
The structure of water supply in Markham, TX is straightforward: one utility provides the bulk of residential service among 1 tracked system, concentrating rate-setting and infrastructure decisions under a single organization.
Overview
We track water quality and home safety data for 1 ZIP code in Markham, Texas, covering 1 community water system serving approximately 1,447 people.
No EPA violations recorded across any ZIP codes in Markham — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Markham: B (82/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Markham water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Markham
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 3 (Low Risk)
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 77456 | B | Markham Municipal Utility District | 1,400 |
All ZIP Codes in Markham
- 77456 [B]
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Updated daily.
CDC Health Data for Markham
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
How Old Is Markham's Housing Stock?
With 76% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
When more than half a city's housing predates the 1986 federal ban on lead solder, plumbing-era lead risk becomes a citywide concern rather than an exception. Markham's median build year of 1961 places it squarely in that category.
Over half of homes in Markham were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.
Source: U.S. Census Bureau ACS B25034.
Markham: Remediation Cost in Perspective
The equity impact of remediation in Markham sits at a moderate level — real enough to plan for, within reach for most.
Remediation costs are moderate relative to home values in Markham. The estimated $1,200–$2,500 range is manageable for most homeowners but still worth budgeting for. Home values are 48% below the Texas average.
Protecting Children from Lead in Markham
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
Older stock in Markham represents 76% of the inventory, and citywide monitoring runs at or above the federal action level — making an in-home read a standard household-level step.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Markham
Within the NFIP's national dataset, Markham falls in moderate-exposure territory — 21 documented incidents spanning multiple decades, with 100% of local ZIP codes sitting inside FEMA flood boundaries. That combination warrants inclusion in any thorough local water quality review.
Markham has a moderate flood history with 21 FEMA claims averaging $23,631 per payout. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$1,800</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
Deep Dive Reports
Detailed analysis for Markham, TX