Worthington Water Supply
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
- 382 people
- Connections
- 187
- Water source
- Groundwater
- Based in
- Worthington, IA
- County
- Dubuque
- Owner
- Local government
The ZIP code it serves
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, total trihalomethanes (TTHM), nitrate, arsenic, chromium (total) and haloacetic acids (HAA5): Iowa’s own results, samples taken from April 8, 2020 to April 1, 2026, with EPA’s 2012 to 2019 file for earlier years.
Below EPA’s limits3
Fluoride
Forms or is added in treatment
1.6ppm
Highest yearly average, 2022
Averaged by year, the highest was 1.6 ppm, in 2022, 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 2.0 ppm, in 2013.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
Total trihalomethanes (TTHM)
Forms or is added in treatment
12ppb
Highest yearly average, 2022 to 2025
Averaged by year, the highest was 12 ppb, in 2025, below EPA’s legal limit of 80 ppb. That was also the latest 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
1.0ppm
Highest sample; found in 1 of 7
2026: not found
The highest sample, in 2022, was 1.0 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, it wasn’t found in its one sample.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Chromium (total)
- Haloacetic acids (HAA5)
- Lead
Violations since 2016
No health-based violations on file with EPA since 2016.
What this report can’t tell you
Everything else. Fluoride, total trihalomethanes (TTHM), nitrate, arsenic, chromium (total) and haloacetic acids (HAA5) results here are Iowa’s own from 2020 on, with EPA’s national file for 2012 to 2019. Worthington Water Supply’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 April 8, 2020 to April 1, 2026.
Testing your own tap
The 3 labs Iowa certifies closest to the area Worthington Water Supply serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Dubuque County Health Department
Dubuque, IA · about 20 miles
Certified for bacteria
ChemRight Laboratories
Maquoketa, IA · about 30 miles
Certified for bacteria, nitrate, minerals and other inorganics
Linn County Public Health Department
Cedar Rapids, IA · about 40 miles
Certified for bacteria, nitrate
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 IowaSources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- Iowa Department of Natural Resources, Water Supply Programs, results from Jan. 1, 2020 to Oct. 6, 2026, read Oct. 8, 2026
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Certified labs: Iowa DNR, laboratories certified for drinking water, read Oct. 10, 2026; distances from the Census 2020 ZIP code tabulation area gazetteer
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID IA3189001. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Nothing here is above a health goalIn EPA’s and Iowa’s records for this utility. They don’t cover everything, which is why the next step matters.Every contaminant TapBuff tracks
- Get the utility’s own reportWorthington Water Supply must send you a water quality report every year. It covers contaminants this page does not show.How to read it
- Test your own tap for leadYour service line, solder and fixtures decide the lead at your faucet, not the utility’s average.Lead in your water: what to do
- Decide if you want a filter at allA filter for taste or chlorine is a preference, not a need. The standards say what each kind can do.NSF/ANSI standards, decoded