Markham, IL: 7 Violations — 60/100 (2026)
1 ZIP code · 4 water systems · Updated 2026-06-03
Compliance figures for Markham indicate average water quality in IL overall — some service areas have recorded health-based violations in recent monitoring cycles, while others operate cleanly, making system-level data the most actionable reference point for residents.
How Markham Compares
Data: EPA SDWIS Last verified: 2026-06-03
Markham Water: The Quick Version
- Your city's water systems recorded 7 violations in the past 5 years.
- Average lead level: 0.003 mg/L.
- Homes built before 1986: 87% — older plumbing may contain lead solder.
- Estimated remediation: $2,100 per household.
- CDC health risk index: 11.18.
Water Systems Serving Markham
Residential water in Markham, IL is supplied by 3 separate utilities — not one centralized authority. Each of those providers operates under its own service territory boundary, maintains its own distribution infrastructure, and files compliance documentation with the EPA on its own timeline. Federal data counts 4 water systems in the area, with these providers collectively accounting for the dominant share of household connections.
Overview
We track water quality and home safety data for 1 ZIP code in Markham, Illinois (population ~10,980), covering 4 community water systems serving approximately 65,003 people region-wide.
1 of 1 ZIP code (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Markham: C (60/100)
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: Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0030 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 2 (Moderate Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Surface Water Treatment Rule | Treatment Technique | 4 | 1 |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 2 | 1 |
| Stage 2 DBP Rule | Treatment Technique | 2 | 1 |
| Lead and Copper Rule | Treatment Technique | 2 | 1 |
| Consumer Confidence Report Rule | Reporting | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 60428 | C | 7 | 0 | Markham |
All ZIP Codes in Markham
- 60428 [C] — 7 violations
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
Key Contaminants Detected in Markham
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
How Old Is Markham's Housing Stock?
With 87% 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
Two dates define the high-risk tiers of residential plumbing from a lead standpoint: 1970, before which lead pipes were commonly installed for service connections, and 1986, before which lead solder was standard in copper plumbing. A median build year of 1966 places Markham's housing distribution well within that older risk zone. The bar chart above breaks down how much of the stock falls into each era — and the pre-1986 share alone represents more than half the residential inventory, making plumbing-era risk a defining characteristic of the local water safety picture.
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
Across the Markham housing market, the estimated remediation share lands in a middle tier — not a minor footnote, but not a prohibitive burden either; the cost-to-value ratio reflects a moderate equity commitment, one that sits above routine maintenance territory and warrants a dedicated line in the household budget.
Remediation costs are moderate relative to home values in Markham. The estimated $1,100–$3,400 range is manageable for most homeowners but still worth budgeting for. Home values are 35% below the Illinois 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.
Wherever 87% of local housing was built before solder rules changed — as is the case in Markham — a faucet-level sample closes the gap that aggregate utility data cannot.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Markham
Markham's flood exposure sits in the moderate range: 240 NFIP claims on record and 100% of ZIP codes within FEMA-designated flood zones. Residents with private wells or older infrastructure have reasonable grounds to factor flood timing into their water quality awareness.
Markham has a moderate flood history with 240 FEMA claims averaging $2,878 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>$2,100</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. Filters rated for Surface Water Treatment Rule can reduce the most common contaminant found in Markham's water.
- Check your home's plumbing. With 87% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Markham, IL