Northwestern W and SD - McComb
What EPA’s and Ohio’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
- 1,527 people
- Connections
- 626
- Water source
- Surface water bought from another system
- Based in
- Bowling Green, OH
- County
- Hancock
- Owner
- Local government
- Hardness
- Hard
The ZIP code it serves
The short answer
1 result is above EPA’s legal limit. The worst: Haloacetic acids (HAA5), above the legal limit. 7 health-based violations since 2016.
What was found
Lead and copper: copper at 270 mg/L (2005) and copper at 198 mg/L (2004) are left out of this report: they are among the results Ohio sent EPA in 2006, all at µg/L magnitudes though EPA’s file marks them mg/L.
Haloacetic acids (HAA5), total trihalomethanes (TTHM), fluoride, nitrate, arsenic and chromium (total): Ohio’s own results, samples taken from Jan. 2, 2020 to Oct. 3, 2025, with EPA’s 2012 to 2019 file for earlier years.
Above the legal limit1
Haloacetic acids (HAA5)
Forms or is added in treatment
71.8ppb
Highest yearly average, 2020 to 2025
2025 average: 25.7 ppb
Averaged by year, the highest was 71.8 ppb, in 2023, above EPA’s legal limit of 60 ppb. Its highest single sample was 137 ppb. In 2025, the latest year on file, its 11 samples averaged 25.7 ppb. EPA recorded violations for haloacetic acids (HAA5) at this utility in 2022, 2023 and 2024. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 47 ppb, in 2014.
What handles it
No certification claim covers this compound yet.
Below EPA’s limits3
Total trihalomethanes (TTHM)
Forms or is added in treatment
68.6ppb
Highest yearly average, 2020 to 2025
2025 average: 43.6 ppb
Averaged by year, the highest was 68.6 ppb, in 2020, below EPA’s legal limit of 80 ppb. Its highest single sample was 121 ppb. In 2025, the latest year on file, its 11 samples averaged 43.6 ppb. EPA recorded no violation for total trihalomethanes (TTHM) at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 95.9 ppb, in 2012, and EPA recorded violations in 2012, 2013 and 2014.
What handles it
- NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
- NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
Fluoride
Forms or is added in treatment
1.2ppm
Highest yearly average, 2020 to 2023
2023, one sample: 1.1 ppm
Averaged by year, the highest was 1.2 ppm, in 2020, below EPA’s legal limit of 4.0 ppm. In 2023, the latest year on file, its one sample was 1.1 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.1 ppm, in 2018.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
Nitrate
Comes from the source
1.7ppm
Highest sample; found in 30 of 46
2023 average: 0.42 ppm
The highest sample, in 2023, was 1.7 ppm, below EPA’s legal limit of 10 ppm. That was also the latest year on file, and its 10 samples averaged 0.42 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 2.1 ppm, in 2013.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
3 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Chromium (total)
- Lead
Hardness
Hard, typically 128 mg/L (7.5 grains per gallon), across 2 sampling points, in 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.
Violations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| Total Haloacetic Acids (HAA5) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2024 to March 31, 2024 | 0.061 MG/L | Resolved |
| Total Haloacetic Acids (HAA5) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2023 to Dec. 31, 2023 | 0.069 MG/L | Resolved |
| Total Haloacetic Acids (HAA5) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2023 to Sept. 30, 2023 | 0.078 MG/L | Resolved |
| Total Haloacetic Acids (HAA5) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2023 to June 30, 2023 | 0.086 MG/L | Resolved |
| Total Haloacetic Acids (HAA5) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2023 to March 31, 2023 | 0.08 MG/L | Resolved |
| Total Haloacetic Acids (HAA5) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2022 to Dec. 31, 2022 | 0.075 MG/L | Resolved |
| Total Haloacetic Acids (HAA5) | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2022 to Sept. 30, 2022 | 0.068 MG/L | Resolved |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 3 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Haloacetic acids (HAA5), total trihalomethanes (TTHM), fluoride, nitrate, arsenic and chromium (total) results here are Ohio’s own from 2020 on, with EPA’s national file for 2012 to 2019. Northwestern W and SD - McComb’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; Ohio’s results run from Jan. 2, 2020 to Oct. 3, 2025.
Testing your own tap
The 3 labs Ohio certifies closest to the area Northwestern W and SD - McComb serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Kleinfelder Water Technologies Laboratory
McClure, OH · about 18 miles
Certified for bacteria
BoJhun Environmental Services
Fostoria, OH · about 22 miles
Certified for bacteria
Eurofins DW and WW Central - Lima
Lima, OH · about 32 miles
Certified for bacteria
Sources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- Ohio Environmental Protection Agency, Division of Drinking and Ground Waters, results from Jan. 2, 2020 to Dec. 31, 2025, read Oct. 17, 2026
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Certified labs: Ohio EPA, laboratories certified/accepted to perform analyses on public drinking water, read Oct. 10, 2026; distances from the Census 2020 ZIP code tabulation area gazetteer
- Hardness: Ohio Environmental Protection Agency, Division of Drinking and Ground Waters, results from Sept. 3, 2024 to Sept. 10, 2024, read Oct. 17, 2026
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID OH3200411. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Read up on Haloacetic acids (HAA5)What each one does to health, where it comes from, and the certification claim that addresses it.About Haloacetic acids (HAA5)
- Get the utility’s own reportNorthwestern W and SD - McComb 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