Ottawa
EPA ID: IL0990800 · 18,097 people served · 5 ZIP codes
Compliance tracking for Ottawa shows 66 pending violations logged in the EPA system — the supplier delivers water to approximately 18,097 residents while those findings remain open.
Data: EPA SDWIS Last verified: 2026-04-02
Compliance Trajectory
Stable · Risk tier: High · 95% chance of violation in next 12 months
Violations went from 7 (2023) to 1 (2025). Violation counts have remained relatively steady.
Service Area Map
Coverage area for Ottawa Source: EPA SDWIS service area boundaries.
Service area boundary — Grade C
Service Area Demographics
The Ottawa serves a community with a median household income of $81,910 and an estimated 37,197 residents across its service area. Approximately 65% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Ottawa's water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
About 1% of homes in LaSalle County, Illinois rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Wastewater Proximity Note: This service area ranks in the 80th percentile nationally for proximity to wastewater discharge points.
Superfund Proximity Note: This service area ranks in the 70th percentile nationally for proximity to Superfund (NPL) sites. Groundwater sources near contaminated sites may face elevated risk from industrial chemicals.
Infrastructure Risk
Detected Contaminants
How Ottawa compares to EPA limits
What This Means For You
Consumer Confidence Report Rule at 26 mg/L exceeds the EPA maximum of mg/L.
Total Trihalomethanes (TTHM) at 2 mg/L exceeds the EPA maximum of 0.08 mg/L. Bladder & rectal cancer risk; reproductive concerns. Consider granular activated carbon (GAC) filtration.
Revised Total Coliform Rule at 18 presence exceeds the EPA maximum of presence.
Lead and Copper Rule at 15 mg/L exceeds the EPA maximum of mg/L.
Stage 2 DBP Rule at 4 mg/L exceeds the EPA maximum of mg/L.
Total Trihalomethanes (TTHM) was detected in this water system. granular activated carbon (GAC) 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
OTTAWA (EPA ID: IL0990800) is a community water system in Illinois that serves approximately 18,097 people from groundwater sources.
This system provides water to 5 ZIP codes across 5 communities.
Average Home Safety Score: C (63/100)
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 |
|---|---|---|---|
| September 26, 2025 | Lead and Copper Rule | Monitoring | Unresolved |
| September 1, 2025 | Consumer Confidence Report Rule | Monitoring | Unresolved |
| September 1, 2025 | Revised Total Coliform Rule | Monitoring | Unresolved |
| August 30, 2025 | Lead and Copper Rule | Monitoring | Unresolved |
| August 22, 2025 | Lead and Copper Rule | Monitoring | Unresolved |
| August 20, 2025 | Lead and Copper Rule | Monitoring | Unresolved |
| August 1, 2025 | Consumer Confidence Report Rule | Monitoring | Unresolved |
| August 1, 2025 | Revised Total Coliform Rule | Monitoring | Unresolved |
| July 31, 2025 | Lead and Copper Rule | Monitoring | Unresolved |
| July 2, 2025 | Stage 2 DBP Rule | Monitoring | Unresolved |
| July 1, 2025 | Surface Water Treatment Rule | Monitoring | Unresolved |
| July 1, 2025 | Consumer Confidence Report Rule | Monitoring | Unresolved |
| July 1, 2025 | Revised Total Coliform Rule | Monitoring | Unresolved |
| June 7, 2025 | Lead and Copper Rule | Monitoring | Unresolved |
| June 1, 2025 | Consumer Confidence Report Rule | Monitoring | Unresolved |
| June 1, 2025 | Revised Total Coliform Rule | Monitoring | Unresolved |
| May 1, 2025 | Consumer Confidence Report Rule | Monitoring | Unresolved |
| May 1, 2025 | Revised Total Coliform Rule | Monitoring | Unresolved |
| April 19, 2025 | Lead and Copper Rule | Monitoring | Unresolved |
| December 1, 2024 | Consumer Confidence Report Rule | Monitoring | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Consumer Confidence Report Rule | Reporting Failure | 26 | No |
| Revised Total Coliform Rule | Microbiological | 18 | No |
| Lead and Copper Rule | Treatment Failure | 15 | No |
| Stage 2 DBP Rule | Treatment Failure | 4 | Yes |
| Surface Water Treatment Rule | Treatment Failure | 3 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 2 | No |
| Gross Beta | Radionuclides | 2 | Yes |
| Contaminant 4109 | Other Violation | 2 | No |
| Stage 1 DBP Rule | Treatment Failure | 1 | No |
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
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: 4 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 Ottawa (IL0990800) on EPA.gov.
Frequently Asked Questions
Is Ottawa water safe to drink?
Ottawa has recorded 3 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 Ottawa serve?
Ottawa serves approximately 18,097 people across 5 ZIP codes in Illinois.
Where does Ottawa get its water?
The primary water source is groundwater.
Water Source & Treatment
Where this water originates and how it's treated before reaching your tap.
Source: OTTAWA Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility. Treatment and source data are sourced from the utility's published CCR filings.
Treatment regime
How this utility classifies its treatment process and what each reported treatment chemical does.
Treatment chemicals and what each one does
Chemical names are reported verbatim by the utility. Purpose categories are ZipCheckup annotations based on standard drinking-water treatment practice.
Treatment classification and chemical list sourced from OTTAWA 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 →
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.
How Water Systems Appear in Rankings
Water systems are evaluated by violation history, contaminant detections, and service population. Larger systems with more service connections appear in more rankings.
- #35 / 50 Highest Exposure Burden (Illinois)
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
Ottawa (EPA ID: IL0990800) — request the latest Consumer Confidence Report or ask about specific contaminants.