Oak Lake Maintenance, Inc.

What EPA’s and Iowa’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: 128 people
Connections: 53
Water source: Groundwater
Based in: Algona, IA
County: Kossuth
Owner: Private

The ZIP code it serves

50511

The short answer

Nothing in EPA’s and Iowa’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, plus lead and copper, not everything. No health-based violations on file since 2016.

What was found

Fluoride, arsenic, chromium (total) and nitrate: Iowa’s own results, samples taken from June 24, 2020 to June 25, 2026, with EPA’s 2012 to 2019 file for earlier years.

Below EPA’s limits1

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.92ppm

Highest yearly average, 2024

Averaged by year, the highest was 0.92 ppm, in 2024, below EPA’s legal limit of 4.0 ppm. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.0 ppm, in 2015.

What handles it

NSF/ANSI 58 look for “Fluoride Reduction”
NSF/ANSI 53 look for “Fluoride”

4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.

Arsenic
Chromium (total)
Lead
Nitrate

Violations since 2016

No health-based violations on file with EPA since 2016. There are 2 monitoring or reporting violations: a sample missed, late or not reported.

What this report can’t tell you

Everything else. Fluoride, arsenic, chromium (total) and nitrate results here are Iowa’s own from 2020 on, with EPA’s national file for 2012 to 2019. Oak Lake Maintenance, Inc.’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; Iowa’s results run from June 24, 2020 to June 25, 2026.

Testing your own tap

Oak Lake Maintenance, Inc.’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 Iowa certifies.

The 3 labs Iowa certifies closest to the area Oak Lake Maintenance, Inc. serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

State Hygienic Laboratory - Lakeside
Milford, IA · about 51 miles
Certified for bacteria, nitrate, minerals and other inorganics
(712) 337-3669
AgSource
Ellsworth, IA · about 61 miles
Certified for bacteria, nitrate, metals, minerals and other inorganics
(515) 297-8103
Foundation Analytical Laboratory
Cherokee, IA · about 72 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, PFAS
(712) 225-6989

State Hygienic Laboratory at the University of Iowa: Through the Grants-to-Counties program, private well owners in participating counties can have their water tested for total coliform bacteria and nitrate. Start with the county sanitarian at your county health department. No cost in a participating county. The Grants-to-Counties Program, State Hygienic Lab at the University of Iowa.

All 36 certified labs for Iowa