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Gc Mankato Hill LLC

What EPA’s and Minnesota’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
140 people
Connections
8
Water source
Groundwater
Based in
Mankato, MN
County
Blue Earth
Owner
Private
The ZIP code it serves

56001

The short answer

1 result is above EPA’s legal limit, and 1 more is above the limit’s level with no violation recorded. The worst: Copper, above the action level. 1 health-based violation since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2020 to 2025.

Arsenic, haloacetic acids (HAA5), total trihalomethanes (TTHM) and nitrate: Minnesota’s yearly summaries per water system, 2023 to 2025, with EPA’s 2012 to 2019 file for earlier years.

Above the legal limit1

Copper

Comes from pipes, often your own

Above the action level

1.4ppm

90th percentile, 2025

In the latest period, 9 in 10 homes sampled were at or below 1.4 ppm, above EPA’s action level of 1.3 ppm.

What handles it

Above the limit’s level, no violation recorded1

Arsenic

Comes from the source

Above the limit’s level, no violation

10.9ppb

Highest yearly average, 2023 to 2025

2025 average: 5.8 ppb

Averaged by year, the highest was 10.9 ppb, in 2024, above EPA’s legal limit of 10 ppb. In 2025, the latest year on file, it averaged 5.8 ppb. EPA judges this limit on running averages at each sampling point, and recorded no violation for arsenic at this utility since 2020. Results like these with no violation often include water sampled before treatment or blending; the utility’s annual report says what reaches the tap. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 7.8 ppb, in 2018.

What handles it

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

Below EPA’s limits3

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

1.7ppb

Highest yearly average, 2024

Averaged by year, the highest was 1.7 ppb, in 2024, below EPA’s legal limit of 60 ppb. That is the only year on file.

What handles it

No certification claim covers this compound yet.

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

1.3ppb

Highest yearly average, 2024

Averaged by year, the highest was 1.3 ppb, in 2024, below EPA’s legal limit of 80 ppb. That is the only year on file.

What handles it

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

Nitrate

Comes from the source

Below EPA’s limits

0.1ppm

Highest yearly average, 2023 to 2025

Averaged by year, the highest was 0.1 ppm, in 2025, below EPA’s legal limit of 10 ppm. That was also the latest year on file.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
One compound tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Lead

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: Copper Reduction, Arsenic (Pentavalent)<=50 ppb Reduction

    For: Copper, Arsenic

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

  • NSF/ANSI 58

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

    For: Copper, Arsenic

    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

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Lead and Copper RuleA required study or plan for corrosion control was not done on time.EPA: OCCT/SOWT Study/RecommendationApril 1, 2026—Resolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 10 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Arsenic, haloacetic acids (HAA5), total trihalomethanes (TTHM) and nitrate results here are Minnesota’s own yearly summaries from 2023 on, with EPA’s national file for 2012 to 2019. Gc Mankato Hill LLC’s own annual report, which it must send you every year, has 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; Minnesota’s yearly summaries cover 2023 to 2025.

Testing your own tap

Gc Mankato Hill LLC’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 Minnesota certifies.

The 3 labs Minnesota certifies closest to the area Gc Mankato Hill LLC serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • UC Laboratory

    Janesville, MN · about 13 miles

    Certified for bacteria, nitrate, metals

    (507) 234-5835

  • Minnesota Valley Testing Laboratories, Inc.

    New Ulm, MN · about 27 miles

    Certified for bacteria, nitrate, lead and copper, metals

    (507) 354-8517

  • RMB Environmental Laboratories, Inc. - Burnsville

    Burnsville, MN · about 57 miles

    Certified for bacteria, nitrate

    (952) 456-8470

All 24 certified labs for Minnesota

Sources

PWSID MN1070024. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Blue Earth County

All Minnesota utilities

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