Joint Muni WSC
What EPA’s and South Carolina’s records show in this utility’s water: PFAS and lithium; nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.
- Serves
- 54,868 people
- Connections
- 22,124
- Water source
- Surface water bought from another system
- Based in
- Lexington, SC
- County
- Lexington
- Owner
- Local government
The short answer
2 results are above EPA’s new limit, which takes effect in 2029, and 1 more is above the health goal. The worst: PFOS, above EPA’s new limit (2029). 1 health-based violation since 2016.
What handles itWhat was found
PFAS and lithium: EPA UCMR 5, samples taken from Nov. 15, 2023 to Aug. 12, 2024.
Lead and copper: EPA SDWIS monitoring periods ending 2007 to 2025.
Haloacetic acids (HAA5) and total trihalomethanes (TTHM): South Carolina’s own results, samples taken from Feb. 3, 2020 to Aug. 3, 2026, with EPA’s 2012 to 2019 file for earlier years.
PFAS: PFOS, PFOA and HFPO-DA (GenX) were found, of the six PFAS in EPA’s 2024 drinking water rule; their results are below. Two other PFAS with no federal limit were found, the highest PFPeA at 4.8 ppt: see them below.
EPA’s 2024 PFAS rule, compound by compound
| PFAS | EPA’s limit | Result |
|---|---|---|
| PFOA | 4.0 ppt | Above EPA’s new limit (2029)4.4 ppt highest, found in 2 of 4 samples. Details |
| PFOS | 4.0 ppt | Above EPA’s new limit (2029)6.2 ppt highest, found in 4 of 4 samples. Details |
| PFHxS | 10 ppt | Not foundNot found in any of 4 samples, below 3 ppt |
| PFNA | 10 ppt | Not foundNot found in any of 4 samples, below 4 ppt |
| HFPO-DA (GenX) | 10 ppt | At EPA’s limit, as EPA rounds10.1 ppt highest, found in 4 of 4 samples. Details |
| PFBS | Index only | Not foundNot found in any of 4 samples, below 3 ppt |
| Hazard IndexPFHxS, PFNA, HFPO-DA and PFBS together | 1 | Doesn’t applyDoesn’t apply: no sampling location found two or more of the four |
| Results from EPA’s UCMR 5 sampling. “Below” is the lab’s reporting level: a result under it reads as not found, which is not the same as zero. The limits are EPA’s 2024 rule, with compliance due from 2029; EPA has since proposed changes to some of them, explained on each compound’s page. PFBS has no limit of its own and counts only toward the Hazard Index, which adds up the four, each against EPA’s health-based level, from each sampling location’s average, as EPA’s UCMR 5 summary does. It counts only where two or more of the four were found, and is above the limit from 1.5. | ||
About PFAS certifications
NSF’s PFAS claims are tested to below 20 ppt. EPA’s limit is 4.0 ppt, and EPA says no certification yet shows a filter reaching its levels.
Above EPA’s new limit, which takes effect in 20292
PFOS
Comes from the source
6.2ppt
Highest sample, Feb. 13, 2024; found in 4 of 4
The highest sample was 6.2 ppt, above EPA’s new limit of 4.0 ppt, which takes effect in 2029. EPA’s health goal is zero. Compliance will be judged on a running annual average, not one sample. Averaged by sampling location, as EPA compares its UCMR 5 results with the limit, the highest was 5.6 ppt, also above it.
What handles it
- NSF/ANSI 53 look for “PFOS Reduction”
- NSF/ANSI 58 look for “Perfluorooctane Sulfonate (PFOS)”
PFOA
Comes from the source
4.4ppt
Highest sample, Feb. 13, 2024; found in 2 of 4
The highest sample was 4.4 ppt, above EPA’s new limit of 4.0 ppt, which takes effect in 2029. EPA’s health goal is zero. Compliance will be judged on a running annual average, not one sample. Averaged by sampling location, as EPA compares its UCMR 5 results with the limit, the highest was 2.1 ppt, below it.
What handles it
- NSF/ANSI 53 look for “PFOA Reduction”
- NSF/ANSI 58 look for “Perfluorooctanoic Acid (PFOA)”
Above the health goal1
Lead
Comes from pipes, often your own
4.0ppb
90th percentile, 2023 to 2025
In the latest period, 9 in 10 homes sampled were at or below 4.0 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027. EPA’s health goal for lead is zero.
What handles it
- NSF/ANSI 53 look for “Lead Reduction”
- NSF/ANSI 58 look for “Lead Reduction”
Below EPA’s limits3
HFPO-DA (GenX)
Comes from the source
10.1ppt
Highest sample, Aug. 12, 2024; found in 4 of 4
The highest sample was 10.1 ppt. As EPA rounds results, that is at EPA’s new limit of 10 ppt, which takes effect in 2029, not above it: EPA counts a result as above it from 15 ppt. Averaged by sampling location, as EPA compares its UCMR 5 results with the limit, the highest was 8.3 ppt, below it.
What handles it
No certification claim covers this compound yet.
Haloacetic acids (HAA5)
Forms or is added in treatment
25.8ppb
Highest yearly average, 2020 to 2026
2026 average: 19.4 ppb
Averaged by year, the highest was 25.8 ppb, in 2025, below EPA’s legal limit of 60 ppb. Its highest single sample was 49.9 ppb. In 2026, the latest year on file, its 12 samples averaged 19.4 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 48.6 ppb, in 2016, and EPA recorded a violation in 2016.
What handles it
No certification claim covers this compound yet.
Total trihalomethanes (TTHM)
Forms or is added in treatment
21.8ppb
Highest yearly average, 2020 to 2026
2026 average: 19.4 ppb
Averaged by year, the highest was 21.8 ppb, in 2025, below EPA’s legal limit of 80 ppb. Its highest single sample was 30.6 ppb. In 2026, the latest year on file, its 12 samples averaged 19.4 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 69.8 ppb, in 2013.
What handles it
- NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
- NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
Also found, with no federal limit
EPA measured these PFAS to learn how often they occur. None has a legal limit or a health goal yet.
| Compound | Highest sample | Found in | Certification claim |
|---|---|---|---|
| PFPeA | 4.8 ppt | 4 of 4 | None covers it |
| PFHxA | 4.5 ppt | 4 of 4 | None covers it |
25 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- 11Cl-PF3OUdS
- 4:2 FTS
- 6:2 FTS
- 8:2 FTS
- 9Cl-PF3ONS
- ADONA
- Lithium
- NEtFOSAA
- NFDHA
- NMeFOSAA
- PFBA
- PFBS
- PFDA
- PFDoA
- PFEESA
- PFHpA
- PFHpS
- PFHxS
- PFMBA
- PFMPA
- PFNA
- PFPeS
- PFTA
- PFTrDA
- PFUnA
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: PFOS Reduction, PFOA Reduction, Lead Reduction
For: PFOS, PFOA, Lead
Other certifiers’ wording: Total PFAS Reduction; Perfluorooctane Sulfonate (PFOS); Perfluorooctanoic Acid (PFOA)
- NSF/ANSI 58
Claims: Perfluorooctane Sulfonate (PFOS), Perfluorooctanoic Acid (PFOA), Lead Reduction
For: PFOS, PFOA, Lead
At the tap, or for the whole house?
Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. 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
ZeroWater 10 Cup Pitcher (ZP-010)
Pitcher
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53checked Oct. 4, 2026
Certified for: PFOS, PFOA, Lead
Aquasana Claryum Direct Connect (AQ-MF-1)
Under-sink carbon
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 16, 2026
Certified for: PFOS, PFOA, Lead
Express Water StreamLine Direct Connect System (USC001)
Under-sink carbon
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 16, 2026
Certified for: PFOS, PFOA, Lead
Under-sink reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58checked Oct. 4, 2026
Certified for: PFOS, PFOA, Lead
Under-sink reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58checked Oct. 9, 2026
Certified for: PFOS, PFOA, Lead
Disinfectant
Joint Muni WSC reported adding chloramine before water enters its pipes, at its one sampling point, in its 2023 to 2024 sampling for EPA.
Chloramine is chlorine combined with ammonia. It lasts longer in the pipes, and unlike chlorine, it doesn’t leave water that sits out. A filter’s chlorine claim doesn’t cover it: look for the separate chloramine claim under NSF/ANSI 42. No shower filter can carry one: NSF/ANSI 177, the shower filter standard, covers free chlorine only. Fish, turtles and frogs need it removed from their water. This utility buys its water from another system, so what it reported may leave out treatment done before the water reaches it. This is what the utility reported for that sampling. Its annual water quality report says what it uses now.
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 | April 1, 2016 to June 30, 2016 | 0.061 MG/L | Resolved |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. | ||||
What this report can’t tell you
Everything else. Haloacetic acids (HAA5) and total trihalomethanes (TTHM) results here are South Carolina’s own from 2020 on, with EPA’s national file for 2012 to 2019. Joint Muni WSC’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 samples are from Nov. 15, 2023 to Aug. 12, 2024; South Carolina’s results run from Feb. 3, 2020 to Aug. 3, 2026.
Testing your own tap
The 3 labs South Carolina certifies closest to the area Joint Muni WSC serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Water Systems Inc.
West Columbia, SC · about 6 miles
Certified for bacteria
Pace Analytical Services LLC
West Columbia, SC · about 9 miles
Certified for bacteria
Alliance Technical Group LLC - Columbia
Columbia, SC · about 12 miles
Certified for bacteria, nitrate, minerals and other inorganics
Sources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- South Carolina Department of Environmental Services, Bureau of Water, results from Jan. 6, 2020 to Oct. 7, 2026, read Oct. 17, 2026
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Disinfectant: EPA UCMR 5 occurrence data, additional data elements, file of Oct. 15, 2026
- Certified labs: SCDES, Commercial Environmental Laboratory Mapping (CELMapp), labs certified under the Safe Drinking Water Act, read Oct. 11, 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 SC3220003. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Read up on the 3 results above a lineWhat each one does to health, where it comes from, and the certification claim that addresses it.Start with PFOS
- Get the utility’s own reportJoint Muni WSC 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
- Compare certified filtersWhat the filters certified for these results cost over five years, cartridges included.Compare five-year costs