South Desoto Water System
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
- 963 people
- Connections
- 321
- Water source
- Groundwater
- Based in
- Mansfield, LA
- County
- De Soto Parish
- Owner
- Private
The ZIP code it serves
The short answer
1 result is above EPA’s legal limit, and 1 more is above the health goal. The worst: Total trihalomethanes (TTHM), above the legal limit. 41 health-based violations since 2016.
What handles itWhat was found
Copper: EPA’s file records a utility’s copper only when it exceeds the action level. The last here was 1.6 ppm, for the period ending Dec. 31, 2010. None since is on file, so it is not counted as a current finding.
Total trihalomethanes (TTHM), haloacetic acids (HAA5) 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.
Arsenic, fluoride, chromium (total) and uranium: EPA’s compliance monitoring file, samples taken from Oct. 21, 2014 to March 27, 2018. Newer results are in the utility’s annual water quality report.
Above the legal limit1
Total trihalomethanes (TTHM)
Forms or is added in treatment
154ppb
Highest yearly average, 2020 to 2022
Averaged by year, the highest was 154 ppb, in 2022, about twice EPA’s legal limit of 80 ppb. That was also the latest year on file. EPA recorded violations for total trihalomethanes (TTHM) at this utility in 2020, 2021, 2022, 2023, 2024, 2025 and 2026. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 156 ppb, in 2019, and EPA recorded violations in 2015, 2017, 2018 and 2019.
What handles it
- NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
- NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
Above the health goal1
Arsenic
Comes from the source
3.0ppb
Highest yearly average, 2014 to 2017
2017: not found
Averaged by year, the highest was 3.0 ppb, in 2014: below EPA’s legal limit of 10 ppb, but above its health goal of zero. Its highest single sample was 7.0 ppb. In 2017, the latest year on file, it wasn’t found in any of its three samples.
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 limits2
Haloacetic acids (HAA5)
Forms or is added in treatment
28.4ppb
Highest yearly average, 2020 to 2022
Averaged by year, the highest was 28.4 ppb, in 2022, below EPA’s legal limit of 60 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 27 ppb, in 2018.
What handles it
No certification claim covers this compound yet.
Fluoride
Forms or is added in treatment
1.6ppm
Highest yearly average, 2014 to 2018
Averaged by year, the highest was 1.6 ppm, in 2018, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 2.7 ppm. That was also the latest year on file.
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.
- Chromium (total)
- Lead
- Nitrate
- Uranium
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: Trihalomethanes (TTHM) Reduction, Arsenic (Pentavalent)<=50 ppb Reduction
For: Total trihalomethanes (TTHM), Arsenic
Other certifiers’ wording: VOC Reduction; Arsenic (III) (50 ppb influent level)
- NSF/ANSI 58
Claims: Trihalomethanes (TTHM) Reduction, Arsenic (Pentavalent)<=50 ppb Reduction
For: Total trihalomethanes (TTHM), Arsenic
Other certifiers’ wording: Arsenic (Pentavalent)<=300 ppb Reduction; Arsenic (V) (300 ppb influent level)
At the tap, or for the whole house?
These come with the water itself, so a whole-house system certified for the same claims treats every tap and shower. A filter at the tap treats drinking water for much less. 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
Aquasana SmartFlow Reverse Osmosis (AQ-SFRO2)
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Total trihalomethanes (TTHM), Arsenic
Brondell Capella RC250 Reverse Osmosis System
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Total trihalomethanes (TTHM), Arsenic
Countertop reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 4, 2026
Certified for: Total trihalomethanes (TTHM), Arsenic
Aquasana Clean Water Machine (AQ-CWM2)
Countertop
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 9, 2026
Certified for: Total trihalomethanes (TTHM)
Brita Hub Countertop Water Filter System (87340)
Countertop
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 9, 2026
- IAPMO listing:NSF/ANSI 53checked Oct. 9, 2026
Certified for: Total trihalomethanes (TTHM)
Violations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2026 to June 30, 2026 | 0.12 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2026 to March 31, 2026 | 0.13 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2025 to Dec. 31, 2025 | 0.13 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2025 to Sept. 30, 2025 | 0.13 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2025 to June 30, 2025 | 0.14 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2025 to March 31, 2025 | 0.15 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2024 to Dec. 31, 2024 | 0.15 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2024 to Sept. 30, 2024 | 0.15 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2024 to June 30, 2024 | 0.16 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2024 to March 31, 2024 | 0.17 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2023 to Dec. 31, 2023 | 0.16 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2023 to Sept. 30, 2023 | 0.18 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2023 to June 30, 2023 | 0.19 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2023 to March 31, 2023 | 0.2 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2022 to Dec. 31, 2022 | 0.22 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2022 to Sept. 30, 2022 | 0.23 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2022 to June 30, 2022 | 0.19 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2022 to March 31, 2022 | 0.17 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2021 to Dec. 31, 2021 | 0.13 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2021 to Sept. 30, 2021 | 0.1 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2021 to June 30, 2021 | 0.13 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2021 to March 31, 2021 | 0.14 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2020 to Dec. 31, 2020 | 0.17 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2020 to Sept. 30, 2020 | 0.17 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2020 to June 30, 2020 | 0.17 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2020 to March 31, 2020 | 0.17 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2019 to Dec. 31, 2019 | 0.17 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2019 to Sept. 30, 2019 | 0.17 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2019 to June 30, 2019 | 0.16 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2019 to March 31, 2019 | 0.16 MG/L | Archived |
| Groundwater Rule | A significant problem found in a state inspection was not fixed on time.EPA: Failure To Address Deficiency | Oct. 2, 2018 | — | Resolved |
| Groundwater Rule | A significant problem found in a state inspection was not fixed on time.EPA: Failure To Address Deficiency | Oct. 2, 2018 | — | Resolved |
| Groundwater Rule | A significant problem found in a state inspection was not fixed on time.EPA: Failure To Address Deficiency | Oct. 2, 2018 | — | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2018 to Dec. 31, 2018 | 0.15 MG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2018 to Sept. 30, 2018 | 150 UG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2018 to June 30, 2018 | 147 UG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2018 to March 31, 2018 | 144 UG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2017 to Dec. 31, 2017 | 146 UG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2017 to Sept. 30, 2017 | 153 UG/L | Archived |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2017 to June 30, 2017 | 124 UG/L | Archived |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 23 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Total trihalomethanes (TTHM), haloacetic acids (HAA5) 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. Arsenic, fluoride, chromium (total) and uranium come from EPA’s file alone, which ends in 2019. South Desoto Water System’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 Oct. 21, 2014 to March 27, 2018.
Testing your own tap
The 2 labs Louisiana certifies closest to the area South Desoto Water System serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
LDH Shreveport Regional Laboratory
Shreveport, LA · about 46 miles
Certified for bacteria
JRTC & Fort Johnson Environmental Laboratory
Fort Polk, LA · about 60 miles
Certified for bacteria
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 LA1031029. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Read up on the 2 results above a lineWhat each one does to health, where it comes from, and the certification claim that addresses it.Start with Total trihalomethanes (TTHM)
- Get the utility’s own reportSouth Desoto Water System 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
- Compare certified filtersWhat the filters certified for these results cost over five years, cartridges included.Compare five-year costs