Cornish Tap Water Quality Report
Cornish's water has 5 contaminants above EPA MCLGs. We recommend using a certified water filter.
Water system
JEFFERSON CO CONS RWD #1
People Served
8,276
Health-based violations since 2020
10
JEFFERSON CO CONS RWD #1. EPA SDWA violation data as of Q2 2026 (downloaded 2026-07-09).
Latest sample on file
Dec 2024 · JEFFERSON CO CONS RWD #1
Utilities publish newer results in their annual water quality report (Consumer Confidence Report).
Is Cornish Tap Water Safe to Drink?
We strongly recommend using a certified water filter to reduce exposure: Cornish's water has 5 contaminants above EPA health-based guidelines. Check our filter recommendations below for NSF-certified options that can remove the specific contaminants found in Cornish's water.
JEFFERSON CO CONS RWD #1, Cornish's water system, serves 8,276 people. Water quality testing is conducted regularly and reported to the EPA. The latest sample on file for JEFFERSON CO CONS RWD #1 is from Dec 2024.
In EPA's 2023–2026 UCMR 5 testing, JEFFERSON CO CONS RWD #1 measured lithium at up to 38.6 µg/L, which EPA counts as above its health reference level of 10 µg/L. That level is a screening value EPA uses to decide what to study further, not a legal limit, and this result does not change this page's water-quality summary.
Boil water advisories are issued by water systems and state agencies, and they change from day to day. Boil water advisories in Oklahoma
Cornish Water Service Areas
What these numbers actually mean for Cornish, OK
We read Cornish, OK’s published record and send you a short report — which findings warrant a decision, which to ignore, and what to do about it. Including when the answer is nothing.
- 5 contaminants above EPA MCLGs, 4 contaminants with an EPA health goal detected in some samples (no level on file) and 2 health-based EPA violations that began after the latest compliance result on file
- 88 results on file
- 23 PFAS compounds on record
Buying a home here? Property Water Report — $49 Emailed within one business day.
Fluoride in Cornish's water
JEFFERSON CO CONS RWD #1
PWSID OK3003401
JEFFERSON CO CONS RWD #1 reported 0.305 mg/L, below the 0.7 mg/L U.S. Public Health Service recommendation.
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Recommended Water Filters for Cornish
Based on Cornish's water quality data, these NSF-certified filters are recommended to remove contaminants above EPA MCLGs.
Culligan
ZeroWater
NSF Certified:
Flow Rate
1.9 gpm
Daily Production
1 gpd
Highlights:
- Compact design
- Easy to set up
- Affordable
- NSF-42, NSF-53, NSF-401 certified
Removes 19 contaminants:
+14 more
Strontium, Molybdenum, Fluoride, Uranium, Lead, Total PFAS, Chlorine, 25, Phosphorus, Bicarbonate, Calcium, Carbonate, Magnesium, Sodium
AquaTru
Classic
NSF Certified:
Flow Rate
0.04 gpm
Daily Production
600 gpd
Highlights:
- Best overall contaminant reduction score
- Most performance certifications
- Lifetime warranty
- NSF-42, NSF-53, NSF-58, NSF-401 certified
Removes 23 contaminants:
+18 more
Molybdenum, Barium, Chlorine, Arsenic, 83+ contaminants, Calcium, Chloride, Copper, Magnesium, Nitrate, Phosphorus, Sodium, Sulfate, Total Dissolved Solids, Zinc, Total THMs, Chloroform, Nitrate (as N)
AquaTru
Carafe
NSF Certified:
Flow Rate
0.3 gpm
Daily Production
4 gpd
Highlights:
- Verified PFAS reduction
- Glass collection vessel
- Plug-and-play installation
- NSF-53, NSF-42, NSF-58, NSF-401, NSF-372 certified
Removes 17 contaminants:
+12 more
Arsenic, 83+ contaminants, Copper, Total THMs, Chloroform, Chloride, Sulfate, Nitrate (as N), Molybdenum, Barium, Strontium, Uranium
Waterdrop
A1
NSF Certified:
Flow Rate
0.042 gpm
Daily Production
130 gpd
Highlights:
- Built-in UV sterilization
- Easy maintenance with filter change reminders
- NSF-58 certified
- Hot and cold water dispensing
Removes 12 contaminants:
+7 more
Molybdenum, Sulfate, Strontium, Phosphorus, Chlorine, Barium, Nitrate
Verify Your Water Quality with Independent Testing
With 5 contaminants above EPA MCLGs, 4 contaminants with an EPA health goal detected in some samples (no level on file) and 2 health-based EPA violations that began after the latest compliance result on file, independent laboratory testing provides a second opinion and can track changes over time.
SimpleLab
Advanced Home Water Test
$269
Comprehensive water analysis testing over 200 contaminants including bacteria, heavy metals, and chemical compounds.
Tap Score
Haloacetic Acids (HAA9) Test
$275
Tests for disinfection byproducts formed when chlorine reacts with organic matter in water treatment.
Tap Score
Advanced Microplastics Test
$829
Cutting-edge testing for microplastics particles in drinking water using advanced laboratory techniques.
With 5 contaminants above health guidelines, you may want to explore water purification options. Learn how to make distilled water at home for applications like humidifiers, CPAP machines, and baby formula.
On a private well near Cornish? Public-water results do not apply to private wells. See Jefferson County well water testing and USGS risk data — modeled arsenic, nitrate, and the tests to run.
Frequently Asked Questions About Cornish Tap Water
Cornish's water has 5 contaminants above EPA MCLGs. We strongly recommend using a certified water filter to reduce exposure to these contaminants. Check our filter recommendations below for NSF-certified options that can remove the specific contaminants found in Cornish's water. EPA records 2 health-based violations for JEFFERSON CO CONS RWD #1 that began after its latest compliance result on file (Jul 2022): Maximum Contaminant Level Violation, Average (TTHM), 2 violations, the first beginning on October 1, 2022 and the latest on January 1, 2023. Every such result predates them; its later EPA UCMR 5 results (Dec 2024) screen for unregulated contaminants and cannot show the water met this standard, so this page does not call the water safe.
Spotted something off on this page?
Residents keep our data honest.
This form corrects our data; it does not reach JEFFERSON CO CONS RWD #1. For a problem with your water now (discolored water, no water, low pressure, a leak), contact JEFFERSON CO CONS RWD #1 directly.
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