Mascoutah
EPA ID: IL1630800 · 8,759 people served · 3 ZIP codes
Based on the latest federal compliance data, Mascoutah has 1 violation that the EPA has not yet closed — those outstanding findings are part of the enforcement record for a utility that delivers water to approximately 8,759 people throughout its service territory.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Mascoutah Source: EPA SDWIS service area boundaries.
Service area boundary — Grade B
Service Area Demographics
The Mascoutah serves a community with a median household income of $89,257 and an estimated 14,688 residents across its service area. Approximately 59% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
🌊 Where Does Your Water Come From?
Mascoutah's water is drawn from rivers, lakes, or reservoirs. Surface water sources are more exposed to agricultural runoff, stormwater, and upstream discharges, but they typically receive more intensive treatment before reaching your tap.
About 1% of homes in St. Clair County, Illinois rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Superfund Proximity Note: This service area ranks in the 60th percentile nationally for proximity to Superfund (NPL) sites.
Infrastructure Risk
Detected Contaminants
How Mascoutah compares to EPA limits
What This Means For You
Surface Water Treatment Rule at 1 mg/L exceeds the EPA maximum of mg/L.
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 3 detections recorded. 2 exceed federal EPA limits (4 ppt for PFOA/PFOS).
Comparable Water Systems
Similar-sized systems in Illinois
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
Mascoutah (EPA ID: IL1630800) is a community water system in Illinois that serves approximately 8,759 people from surface water sources.
This system provides water to 3 ZIP codes across 2 communities.
Average Home Safety Score: B (79/100)
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 |
|---|---|---|---|
| July 1, 2025 | Surface Water Treatment Rule | Monitoring | Unresolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Surface Water Treatment Rule | Treatment Failure | 1 | No |
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 2 (Moderate Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
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: 2 ZIP codes confirmed via EPA Community Water System Service Area Boundaries v3 plus 1 additional ZIP 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 Mascoutah (IL1630800) on EPA.gov.
Frequently Asked Questions
Is Mascoutah water safe to drink?
Mascoutah has only monitoring/reporting violations, which are procedural in nature. The system meets federal health-based standards.
How many people does Mascoutah serve?
Mascoutah serves approximately 8,759 people across 3 ZIP codes in Illinois.
Where does Mascoutah get its water?
The primary water source is surface water.
Water Source & Treatment
Where this water originates and how it's treated before reaching your tap.
Source: MASCOUTAH Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility. Treatment and source data are sourced from the utility's published CCR filings.
A source water assessment for our supply has been completed by the Illinois EPA.
Treatment regime
How this utility classifies its treatment process and what each reported treatment chemical does.
Watershed exposure sources reported
Land-use and natural conditions identified in the utility's source-water assessment as potential contamination sources upstream of treatment.
Treatment classification and chemical list sourced from MASCOUTAH Consumer Confidence Report.
Treatment intensity is a ZipCheckup-derived classification based on the chemicals and processes the utility reports. Chemicals and contamination sources are taken verbatim from the utility's CCR filing. Routine federal monitoring and contaminant testing shown elsewhere on this page determine whether the water meets safety standards, not the treatment classification.
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 →
Our Community Water Supply has/has not developed a service line material inventory.
Lead Service Line Replacement Tracker
This water utility's lead service line (LSL) replacement program is tracked from public Consumer Confidence Report filings. Email signup notifies subscribers when the utility files an updated replacement plan or progress milestone.
MASCOUTAH
ZipCheckup is not affiliated with this water utility. LSL replacement-program data is sourced from public CCR filings published by the utility. Subscription notifications are based on automated parsing of subsequent CCR releases.
Learn more about Lead and Copper Rule replacement requirements →
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
Mascoutah (EPA ID: IL1630800) — request the latest Consumer Confidence Report or ask about specific contaminants.