City water profile

Water hardness in Tonkawa

Find official utility reports, understand hardness, and check the water system serving your home in Tonkawa, Oklahoma.

Utility-reported hardness

Not yet available

Check your provider and source →

State comparison: Unavailable
Evidence comparison rank: —
Matched utilities: 1
Active health records: 0

Your tap water

What does the utility report?

Match the utility name to your water bill. These results describe the utility’s water, not a test at your home. A ZIP can include several water systems.

Utility hardness unavailable in this index

Nearby river or groundwater samples cannot tell us the hardness coming out of your tap. Ask your water provider for total hardness as CaCO₃, or test it at home.

Find an official utility report →

Convert a hardness result →Test your tap →

Match the name on your water bill

Your utility’s measurements and compliance records

These are possible serving systems. A record for one system does not apply to every home in this ZIP. Confirm your provider before interpreting a measurement or notice. Federal records can lag current utility notices.

EPA snapshot: 2026Q2. Historical window begins Jan 1, 2021.

Tonkawa

OK2003603 · Groundwater · 3,299 people served system-wide

A municipal system, in-state city, and served county all agree with this Census ZCTA.

No active health-based record in this imported snapshot

Find this utility’s official report →

Measurements (2)

An action level is a regulatory trigger, not a pass/fail health boundary. A reported zero is the value in the source record and does not establish that lead is absent at your tap.

Lead (90th percentile)

EPA SDWIS Lead and Copper Rule samples

Below action level

Reported level: 0.0064 mg/L
Action level: 0.015 mg/L

43% of the listed benchmark

Monitoring period: Jan 1, 2023 to Dec 31, 2025

Copper (90th percentile)

EPA SDWIS Lead and Copper Rule samples

Above action level

Reported level: 3.3 mg/L
Action level: 1.3 mg/L

254% of the listed benchmark

Monitoring period: Jul 1, 1998 to Dec 31, 1998

Violation history (11)

Imported violation history for Tonkawa
Rule	Status	Period
Revised Total Coliform Rule	Archived	Feb 1, 2026 to Feb 28, 2026
Chlorine	Archived	Feb 1, 2026 to Feb 28, 2026
E. COLI	Unaddressed	Aug 14, 2025
LEAD AND COPPER RULE REVISIONSHealth-based	Resolved	Oct 17, 2024 to Jul 15, 2025
LEAD AND COPPER RULE REVISIONS	Resolved	Oct 17, 2024 to Jul 15, 2025
TTHM	Resolved	Oct 1, 2022 to Sep 30, 2023
Total Haloacetic Acids (HAA5)	Resolved	Oct 1, 2022 to Sep 30, 2023
E. COLI	Unaddressed	Jan 19, 2017
E. COLI	Unaddressed	Sep 17, 2015
E. COLI	Unaddressed	Sep 18, 2014
E. COLI	Unaddressed	Aug 21, 2014

City summary

What the indexed records say

Tonkawa has 1 published ZIP profile across Kay County. The regional-evidence median is 130 PPM. The city does not meet the stricter comparison standard.

Because only one ZIP is represented, the city median and range are the same local estimate. It should not be read as multiple independent samples across the community. At least one estimate is marked low confidence, so observation distance and date deserve extra attention.

Hardness distribution

How local ZIP estimates compare

Soft0 ZIPs

Moderately hard0 ZIPs

Hard1 ZIP

Very hard0 ZIPs

1 of 1 ZIP profiles have a hardness estimate. Bars count ZIP profiles, not households or laboratory samples.

Evidence quality

Distance, dates, and confidence

Median nearest distance: 20.9 miles
Profiles with evidence: 1/1

Confidence labels

High: 0Moderate: 0Low: 1

Observation window: Sep 14, 2016 to Sep 14, 2016.

ZIP directory

Water reports in Tonkawa

Open a ZIP for site-level provenance and measurements.

ZIP code

74653

Hard

130 PPM

Nearest site: 20.9 mi
Confidence: Low

View full ZIP evidence →

Practical next steps

Move from index to evidence

1. Open your ZIP. Check distance, dates, confidence, and the associated utility.
2. Read the current CCR. Confirm source water, detections, limits, ranges, and notices.
3. Use a measured hardness result. Confirm health concerns or treatment sizing with the right method.

Continue comparing

Other Oklahoma communities

Newkirk

Kay County

442 PPM median

Blackwell

Kay County

— No median

Woodward

Woodward County

140 PPM median

Mooreland

Woodward County

140 PPM median

Commerce

Ottawa County

143 PPM median

Miami

Ottawa County

143 PPM median

Search all 108 Oklahoma cities →

Questions people ask

About water in Tonkawa

Is the water hard?

Check the utility-reported result above when available. Nearby environmental samples cannot establish tap-water hardness. Ask your provider or test your tap.

Is the tap water safe?

Compliance history is utility-wide and cannot guarantee conditions at every tap. Check current notices and test when address-specific evidence is needed.

Do I need treatment?

Choose treatment only after confirming the problem at the property. A softener targets hardness; contaminant treatment requires a matching, verified performance claim.