Nilwood
EPA ID: IL1170750 · 1,394 people served · 2 ZIP codes
Not yet resolved: 4 EPA violations at Nilwood, affecting about 1,394 residents.
Data: EPA SDWIS Last verified: 2026-04-02
Compliance Trajectory
Worsening · Risk tier: High · 95% chance of violation in next 12 months
Violations went from 6 (2021) to 6 (2025). The pattern suggests growing compliance challenges.
Service Area Map
Coverage area for Nilwood Source: EPA SDWIS service area boundaries.
Service area boundary — Grade C
Service Area Demographics
The Nilwood serves a community with a median household income of $54,398 and an estimated 687 residents across its service area. Approximately 79% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: 38% of the population in this service area is classified as disadvantaged under EPA's EJScreen criteria. Communities with higher disadvantaged populations often face disproportionate environmental and health burdens, including aging water infrastructure and limited resources for remediation.
🌊 Where Does Your Water Come From?
Nilwood'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 Macoupin County, Illinois rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Infrastructure Risk
Detected Contaminants
How Nilwood compares to EPA limits
What This Means For You
Contaminant 1006 at 1 mg/L exceeds the EPA maximum of 0.006 mg/L. Cholesterol & blood sugar effects, liver damage. Consider reverse osmosis filtration.
Fecal Coliform at 6 presence exceeds the EPA maximum of presence.
Chlorite at 4 mg/L exceeds the EPA maximum of 1 mg/L. Anemia and nervous system effects in infants and children. Consider ferrous sulfate reduction filtration.
Lead and Copper Rule at 3 mg/L exceeds the EPA maximum of mg/L.
Stage 1 DBP Rule at 1 mg/L exceeds the EPA maximum of mg/L.
Contaminant 1006 was detected in this water system. reverse osmosis filtration can reduce exposure.
Find a certified water filter →Comparable Water Systems
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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
Nilwood (EPA ID: IL1170750) is a community water system in Illinois that serves approximately 1,394 people from surface water sources.
This system provides water to 2 ZIP codes across 2 communities.
Average Home Safety Score: C (69/100)
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 |
|---|---|---|---|
| May 30, 2025 | Lead and Copper Rule | Monitoring | Resolved |
| April 1, 2025 | Chlorite | Health-based | Unresolved |
| March 1, 2025 | Consumer Confidence Report Rule | Monitoring | Resolved |
| March 1, 2025 | Contaminant 1006 | Monitoring | Resolved |
| January 1, 2025 | Chlorite | Health-based | Unresolved |
| July 1, 2023 | Surface Water Treatment Rule | Monitoring | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Fecal Coliform | Microbiological | 6 | Yes |
| Chlorite | Disinfection Byproducts | 4 | Yes |
| Lead and Copper Rule | Treatment Failure | 3 | No |
| Contaminant 1006 | Other Violation | 1 | No |
| Stage 1 DBP Rule | Treatment Failure | 1 | No |
| Surface Water Treatment Rule | Treatment Failure | 1 | No |
| Consumer Confidence Report Rule | Reporting Failure | 1 | No |
Health Risk Details
Chlorite (EPA limit: 1 mg/L)
Anemia and nervous system effects in infants and children At-risk groups: infants, developing fetuses, people with G6PD deficiency.
Removal methods: ferrous sulfate reduction, activated carbon, reverse osmosis. Find the right filter →
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
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Nilwood (IL1170750) on EPA.gov.
Frequently Asked Questions
Is Nilwood water safe to drink?
Nilwood has recorded 10 health-based violations in the past 5 years. While the system is required to treat water to meet federal standards, you may want to consider additional precautions such as a certified water filter.
How many people does Nilwood serve?
Nilwood serves approximately 1,394 people across 2 ZIP codes in Illinois.
Where does Nilwood 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: NILWOOD Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility. Treatment and source data are sourced from the utility's published CCR filings.
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
This system reports zero confirmed lead service lines in its inventory. Unknown-material counts may still warrant verification.
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
Nilwood (EPA ID: IL1170750) — request the latest Consumer Confidence Report or ask about specific contaminants.