Mount Hermon Water District
What EPA’s and CDC’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
- 1,107 people
- Connections
- 369
- Water source
- Groundwater
- Based in
- Mount Hermon, LA
- County
- Washington Parish
- Owner
- Local government
The ZIP code it serves
The short answer
Nothing in EPA’s and CDC’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, plus lead and copper, not everything. 4 health-based violations since 2016.
What was found
Haloacetic acids (HAA5), total trihalomethanes (TTHM) and nitrate: Louisiana’s yearly averages per water system, as CDC’s Environmental Public Health Tracking Network publishes them, 2020 to 2022, with EPA’s 2012 to 2019 file for earlier years.
Fluoride, arsenic, chromium (total) and uranium: EPA’s compliance monitoring file, samples taken from April 8, 2014 to July 31, 2019. Newer results are in the utility’s annual water quality report.
Below EPA’s limits3
Haloacetic acids (HAA5)
Forms or is added in treatment
22.4ppb
Highest yearly average, 2020 to 2022
2022 average: 18.6 ppb
Averaged by year, the highest was 22.4 ppb, in 2020, below EPA’s legal limit of 60 ppb. In 2022, the latest year on file, it averaged 18.6 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 22.5 ppb, in 2018.
What handles it
No certification claim covers this compound yet.
Total trihalomethanes (TTHM)
Forms or is added in treatment
27.8ppb
Highest yearly average, 2020 to 2022
Averaged by year, the highest was 27.8 ppb, in 2022, below EPA’s legal limit of 80 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 32 ppb, in 2017.
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
0.75ppm
Highest yearly average, 2014 to 2019
2019, one sample: 0.5 ppm
Averaged by year, the highest was 0.75 ppm, in 2017, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 1.0 ppm. In 2019, the latest year on file, its one sample was 0.5 ppm.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
5 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Chromium (total)
- Lead
- Nitrate
- Uranium
Violations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| Groundwater Rule | A significant problem found in a state inspection was not fixed on time.EPA: Failure To Address Deficiency | June 24, 2025 | — | Unaddressed |
| Groundwater Rule | A significant problem found in a state inspection was not fixed on time.EPA: Failure To Address Deficiency | June 24, 2025 | — | Unaddressed |
| Groundwater Rule | A significant problem found in a state inspection was not fixed on time.EPA: Failure To Address Deficiency | June 24, 2025 | — | Unaddressed |
| Lead and Copper Rule Revisions | The required inventory of lead service lines was not completed or submitted on time.EPA: LSL Inventory | Oct. 17, 2024 | — | 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) and nitrate results here are Louisiana’s yearly averages as CDC publishes them, from 2020 on, with EPA’s national file for 2012 to 2019. Fluoride, arsenic, chromium (total) and uranium come from EPA’s file alone, which ends in 2019. Mount Hermon Water District’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; CDC’s yearly averages for Louisiana cover 2020 to 2022; EPA’s compliance samples are from April 8, 2014 to July 31, 2019.
Testing your own tap
The 3 labs Louisiana certifies closest to the area Mount Hermon Water District serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
LDH Amite Regional Laboratory
Amite, LA · about 11 miles
Certified for bacteria
Water Test, Inc.
Covington, LA · about 36 miles
Certified for bacteria
Curtis Environmental Services, Inc.
LaPlace, LA · about 51 miles
Certified for minerals and other inorganics, disinfection byproducts
Sources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- CDC Environmental Public Health Tracking Network, yearly averages Louisiana supplied to CDC, 2020 to 2022, read Oct. 8, 2026. TapBuff’s comparisons with EPA’s limits are its own, not CDC’s or Louisiana’s.
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Certified labs: LDH, laboratories certified by Louisiana for drinking water analysis, read Oct. 16, 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 LA1117021. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Nothing here is above a health goalIn EPA’s and CDC’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 reportMount Hermon Water District must send you a water quality report every year. It covers contaminants this page does not show, and has newer results than EPA’s national file for the ones here that come from it.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