Tonkawa
EPA ID: OK2003603 · 3,299 people served · 4 ZIP codes
Pulled from the federal compliance ledger, 27 violations at Tonkawa remain without resolution — the utility delivers drinking water to roughly 3,299 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 1 (2021) to 10 (2025). The pattern suggests growing compliance challenges.
Service Area Map
Coverage area for Tonkawa Source: EPA SDWIS service area boundaries.
Service area boundary — Grade A
Service Area Demographics
The Tonkawa serves a community with a median household income of $62,216 and an estimated 11,255 residents across its service area. Approximately 88% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: 48% 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?
Tonkawa'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 2% of homes in Kay County, Oklahoma 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 Tonkawa compares to EPA limits
What This Means For You
Total Trihalomethanes (TTHM) at 9 mg/L exceeds the EPA maximum of 0.08 mg/L. Bladder & rectal cancer risk; reproductive concerns. Consider granular activated carbon (GAC) filtration.
Arsenic at 1 mg/L exceeds the EPA maximum of 0.01 mg/L.
Fecal Coliform at 36 presence exceeds the EPA maximum of presence.
Lead and Copper Rule at 22 mg/L exceeds the EPA maximum of mg/L.
Consumer Confidence Report Rule at 10 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
Tonkawa (EPA ID: OK2003603) is a community water system in Oklahoma that serves approximately 3,299 people from groundwater sources.
This system provides water to 4 ZIP codes across 4 communities.
Average Home Safety Score: A (87/100)
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 |
|---|---|---|---|
| August 14, 2025 | Total Coliform | Monitoring | Unresolved |
| July 1, 2025 | Stage 1 DBP Rule | Monitoring | Resolved |
| October 17, 2024 | Stage 2 DBP Rule | Health-based | Resolved |
| October 17, 2024 | Stage 2 DBP Rule | Monitoring | Resolved |
| October 1, 2024 | Stage 1 DBP Rule | Monitoring | Resolved |
| October 1, 2024 | Total Trihalomethanes (TTHM) | Monitoring | Resolved |
| July 1, 2024 | Surface Water Treatment Rule | Monitoring | Resolved |
| July 1, 2024 | Total Trihalomethanes (TTHM) | Monitoring | Resolved |
| July 1, 2024 | Consumer Confidence Report Rule | Monitoring | Resolved |
| June 1, 2024 | Revised Total Coliform Rule | Monitoring | Resolved |
| June 1, 2024 | Consumer Confidence Report Rule | Monitoring | Resolved |
| April 1, 2024 | Fecal Coliform | Monitoring | Resolved |
| April 1, 2024 | Revised Total Coliform Rule | Monitoring | Resolved |
| April 1, 2024 | Consumer Confidence Report Rule | Monitoring | Resolved |
| April 1, 2024 | Total Organic Carbon | Monitoring | Resolved |
| February 1, 2024 | Fecal Coliform | Monitoring | Unresolved |
| January 1, 2024 | Fecal Coliform | Monitoring | Unresolved |
| January 1, 2024 | Contaminant 1052 | Monitoring | Unresolved |
| December 1, 2023 | Fecal Coliform | Monitoring | Unresolved |
| November 1, 2023 | Fecal Coliform | Monitoring | Unresolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Fecal Coliform | Microbiological | 36 | No |
| Lead and Copper Rule | Treatment Failure | 22 | No |
| Consumer Confidence Report Rule | Reporting Failure | 10 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 9 | No |
| Revised Total Coliform Rule | Microbiological | 7 | No |
| Total Organic Carbon | Disinfection Byproducts | 3 | No |
| Surface Water Treatment Rule | Treatment Failure | 3 | No |
| Stage 1 DBP Rule | Treatment Failure | 2 | No |
| Stage 2 DBP Rule | Treatment Failure | 2 | Yes |
| Arsenic | Inorganic | 1 | No |
| Contaminant 1052 | Other Violation | 1 | No |
| Total Coliform | Microbiological | 1 | No |
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
| ZIP Code | Lead Level | Exceeds Limit | Sample Date |
|---|---|---|---|
| 74653 | 0.0064 mg/L | No | N/A |
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 3 (Low Risk)
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: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by OK or modeled from parcel and building-footprint data.
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Tonkawa (OK2003603) on EPA.gov.
Frequently Asked Questions
Is Tonkawa water safe to drink?
Tonkawa has recorded 1 health-based violation 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 Tonkawa serve?
Tonkawa serves approximately 3,299 people across 4 ZIP codes in Oklahoma.
Where does Tonkawa get its water?
The primary water source is groundwater.
Contact Your Water Utility
Public-record contact information for the water utility serving this system. Use these channels to request water quality reports, ask about service, or report issues directly.
Contact information from TONKAWA Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility, does not act as its agent, and does not provide customer support for it. Contact details shown are public-record information from CCR filings. For service issues, contact the utility directly using the information above.
Water Source & Treatment
Where this water originates and how it's treated before reaching your tap.
Source: TONKAWA 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.
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 TONKAWA 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.
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.
Aesthetic water quality
These measurements describe the look, taste, and feel of the water this utility delivers. They are not contaminant violations — they sit alongside federal Secondary Maximum Contaminant Levels (SMCLs) which the EPA publishes as non-enforceable guidance.
Aesthetic measurements from TONKAWA Consumer Confidence Report.
Aesthetic measurements are reported by the utility from its annual sampling. EPA Secondary MCLs are advisory thresholds — values outside them indicate aesthetic concerns such as taste or appearance, not health violations. Federal contaminant testing is shown in the sections above.
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
Tonkawa (EPA ID: OK2003603) — request the latest Consumer Confidence Report or ask about specific contaminants.