Markham, VA: High Radon Risk — 53/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
Unlike better-scoring cities in VA, Markham records health-based violations across a meaningful portion of its service areas — the overall safety grade is well below average.
How Markham Compares
Data: EPA SDWIS Last verified: 2026-06-03
Markham Water: The Quick Version
- Homes built before 1986: 51% — older plumbing may contain lead solder.
- Estimated remediation: $3,000 per household.
- CDC health risk index: 12.14 — above typical levels.
Water Systems Serving Markham
Markham, VA draws its water from one primary utility across 1 tracked system.
Overview
We track water quality and home safety data for 1 ZIP code in Markham, Virginia, covering 1 community water system serving approximately 133 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: D (53/100)
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 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 22643 | D | FREEZELAND MANOR SUBDIVISION | 140 |
All ZIP Codes in Markham
- 22643 [D]
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 51% 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
Viewed through the lens of construction era, Markham is predominantly an older city — a median build year of 1985 puts most of the residential inventory in the range where pre-1986 plumbing materials were the standard.
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.
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.
Practically, the structural drivers in Markham — 51% pre-rule stock and citywide monitoring at or beyond the regulatory benchmark — make an in-home draw the practical way to translate aggregate averages into the specific conditions at one address.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Markham
Flood exposure in Markham is meaningful by NFIP measures — 1 claim on record and 100% of ZIP codes carrying FEMA flood zone designations. That level of activity makes flood history a relevant factor when evaluating local water quality over time.
Markham has a moderate flood history with 1 FEMA claims. 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>$3,000</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.
What You Can Do in Markham
- Test your water at home. City-level data shows averages — your tap may differ. NSF-certified test kits cost $20-40 and give results in days.
- Install a certified water filter. An NSF-certified pitcher or under-sink filter removes most common contaminants.
- Check your home's plumbing. With 51% of homes built before 1986, lead solder is a real possibility.
- Review your water system's CCR. Your utility publishes an annual Consumer Confidence Report with detailed test results. Request it or find it online.
Deep Dive Reports
Detailed analysis for Markham, VA