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City of Oberlin

What EPA’s and Kansas’s records show in this utility’s water: nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.

Serves
1,639 people
Connections
970
Water source
Groundwater
Based in
Oberlin, KS
County
Decatur
Owner
Local government
Hardness
Varies by source
The ZIP code it serves

67749

The short answer

1 result is above EPA’s legal limit, and 2 more are above the health goal. The worst: Uranium, above the legal limit. No health-based violations on file since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2012 to 2024.

Copper: EPA’s file records a utility’s copper only when it exceeds the action level. The last here was 1.9 ppm, for the period ending Dec. 31, 1993. None since is on file, so it is not counted as a current finding.

Arsenic, nitrate, fluoride, total trihalomethanes (TTHM), haloacetic acids (HAA5) and chromium (total): Kansas’s own results, samples taken from May 18, 2020 to May 18, 2026, with EPA’s 2012 to 2019 file for earlier years.

Uranium: EPA’s compliance monitoring file, samples taken from Feb. 20, 2012 to Feb. 12, 2018. Newer results are in the utility’s annual water quality report.

Above the legal limit1

Uranium

Comes from the source

Above the legal limit

30.4ppb

Highest yearly average, 2012 to 2018

2018, one sample: 6.3 ppb

Averaged by year, the highest was 30.4 ppb, in 2014, which EPA rounds to 30 ppb to compare: at its legal limit of 30 ppb, not above it. Its highest single sample was 39 ppb. In 2018, the latest year on file, its one sample was 6.3 ppb. EPA judges this limit at each sampling point, and recorded violations for uranium at this utility in 2012, 2013 and 2014.

What handles it

Above the health goal2

Arsenic

Comes from the source

Above the health goal

6.7ppb

Highest yearly average, 2021 to 2024

2024 average: 6.4 ppb

Averaged by year, the highest was 6.7 ppb, in 2021: below EPA’s legal limit of 10 ppb, but above its health goal of zero. Its highest single sample was 7.3 ppb. In 2024, the latest year on file, its three samples averaged 6.4 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 10.7 ppb, in 2013, and EPA recorded violations in 2012, 2013 and 2014.

What handles it

  • NSF/ANSI 58 look for “Arsenic (Pentavalent)<=50 ppb Reduction”
  • NSF/ANSI 53 look for “Arsenic (Pentavalent)<=50 ppb Reduction”

Lead

Comes from pipes, often your own

Above the health goal

1.1ppb

90th percentile, 2022 to 2024

In the latest period, 9 in 10 homes sampled were at or below 1.1 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027. EPA’s health goal for lead is zero.

What handles it

Below EPA’s limits5

Nitrate

Comes from the source

Below EPA’s limits

7.1ppm

Highest sample; found in 27 of 27

2026 average: 3.2 ppm

The highest sample, in 2020, was 7.1 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its three samples averaged 3.2 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 6.8 ppm, in 2018.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.89ppm

Highest yearly average, 2021 to 2024

2024 average: 0.84 ppm

Averaged by year, the highest was 0.89 ppm, in 2021, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.96 ppm. In 2024, the latest year on file, its three samples averaged 0.84 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.66 ppm, in 2018.

What handles it

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

8.7ppb

Highest yearly average, 2020 to 2025

2025, one sample: 3.0 ppb

Averaged by year, the highest was 8.7 ppb, in 2020, below EPA’s legal limit of 80 ppb. In 2025, the latest year on file, its one sample was 3.0 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 52.5 ppb, in 2013.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

3.0ppb

Highest yearly average, 2020 to 2025

2025: not found

Averaged by year, the highest was 3.0 ppb, in 2020, below EPA’s legal limit of 60 ppb. In 2025, the latest year on file, it wasn’t found in its one sample. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 15.5 ppb, in 2013.

What handles it

No certification claim covers this compound yet.

Chromium (total)

Comes from the source

Below EPA’s limits

1.7ppb

Highest yearly average, 2021 to 2024

2024 average: 0.33 ppb

Averaged by year, the highest was 1.7 ppb, in 2021, below EPA’s legal limit of 100 ppb. Its highest single sample was 1.9 ppb. In 2024, the latest year on file, its three samples averaged 0.33 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 3.5 ppb, in 2018.

What handles it

What handles it

A certification covers specific claims, not a whole standard. Look for these claims on the certifier’s listing, not the box. Wording varies a little: NSF writes “Lead Reduction,” WQA just “Lead.”

  • NSF/ANSI 53

    Claims: Arsenic (Pentavalent)<=50 ppb Reduction, Lead Reduction

    For: Arsenic, Lead

    Other certifiers’ wording: Arsenic (III) (50 ppb influent level)

  • NSF/ANSI 58

    Claims: Uranium, Arsenic (Pentavalent)<=50 ppb Reduction, Lead Reduction

    For: Uranium, Arsenic, Lead

    Other certifiers’ wording: Arsenic (Pentavalent)<=300 ppb Reduction; Arsenic (V) (300 ppb influent level)

At the tap, or for the whole house?

Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. How whole-house systems compare.

Filters with those claims on a certifier’s listing

Disclosure: TapBuff earns a commission if you buy through some links on this page. It does not change which standard or filter we name. As an Amazon Associate, TapBuff earns from qualifying purchases. How TapBuff makes money

Compare five-year costs

The best reverse osmosis systems, ranked

The best water filters for lead, ranked

Hardness

Hard to very hard depending on the source, 170 to 315 mg/L (9.9 to 18.4 grains per gallon), across 4 sampling points, 2015 to 2024.

Hardness is calcium and magnesium. EPA sets no limit for it: it shows up as scale on fixtures and in water heaters, and as soap that won’t lather. USGS calls water above 60 mg/L moderately hard, above 120 hard and above 180 very hard.

Softeners compared, salt includedSoftener or salt-free conditioner?Kansas water hardness, utility by utility

Violations since 2016

No health-based violations on file with EPA since 2016. There are 4 monitoring or reporting violations: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Arsenic, nitrate, fluoride, total trihalomethanes (TTHM), haloacetic acids (HAA5) and chromium (total) results here are Kansas’s own from 2020 on, with EPA’s national file for 2012 to 2019. Uranium comes from EPA’s file alone, which ends in 2019. City of Oberlin’s own annual report, which it must send you every year, has newer results for those and the contaminants this page does not show.

  • Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.

  • What it means for your health. This page reports what the records show and EPA’s limits and goals; it is not medical advice. If you are worried about a health effect, talk to a doctor or your local health department.

  • Anything after the latest data. SDWIS data is from 2026 Q3; UCMR 5 didn’t sample this utility; Kansas’s results run from May 18, 2020 to May 18, 2026; EPA’s compliance samples are from Feb. 20, 2012 to Feb. 12, 2018.

Testing your own tap

City of Oberlin’s results are for the water it sends out. What your own service line, solder and fixtures add shows up only in a test of your tap, by a lab Kansas certifies.

No lab Kansas certifies is within 75 miles of the area City of Oberlin serves on the state’s list. Some take samples by mail; the state’s page lists them all.

All 47 certified labs for Kansas

Sources

PWSID KS2003903. Rebuilt from EPA data on Oct. 18, 2026.

Nearby

All Kansas utilities

What to do next