North Alamo WSC water quality report, rewritten
- Serves
- 171,195
- Connections
- 57,065
- Water source
- Surface water
- Based in
- Edinburg, TX
- County
- Hidalgo
- Owner
- Local government
PWSID TX10800292026 edition · EPA data
Read this first
- Lithium (above EPA’s health benchmark) was found in 26 of 26 samples, highest 50 ppb. Above EPA’s health reference level of 10 ppb, a screening level rather than an enforceable limit.
5 health-based violations since 2016. Details are below.
What was found
Highlighted: above the health goal, or EPA’s health benchmark where there is no goal. Circled: above the legal limit in at least one sample, or the action level. Every scale puts that line at its middle.
Lithium (above EPA’s health benchmark)
Comes from the source
50ppb
Highest of 26 samples; found in 26
Above EPA’s health reference level of 10 ppb, a screening level rather than an enforceable limit.
What handles it
No certification claim covers this compound yet.
EPA UCMR 5, samples taken from Feb. 15, 2023 to Nov. 6, 2023. Each blue tick is one sample where it was found.
PFHxS
Comes from the source
3.4ppt
Highest of 26 samples; found in one
Detected, below the legal limit and the health goal.
What handles it
- NSF/ANSI 53Look for: Total PFAS ReductionSame claim, other certifiers’ wording: Perfluorohexane Sulfonic Acid (PFHxS)
NSF’s PFAS claims are tested to below 20 ppt. EPA’s limit is 10 ppt, and EPA says no certification yet shows a filter reaching its levels.
EPA UCMR 5, samples taken on May 8, 2023. Each blue tick is one sample where it was found.
PFBS
Comes from the source
3.0ppt
Highest of 26 samples; found in one
Below EPA’s hazard index benchmark of 2,000 ppt. PFBS has no legal limit or health goal of its own.
What handles it
- NSF/ANSI 53Look for: Total PFAS Reduction
EPA UCMR 5, samples taken on Aug. 8, 2023. Each blue tick is one sample where it was found.
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 |
|---|---|---|---|
| PFBA | 12.2 ppt | 12 of 26 | None covers it |
| PFPeA | 3.8 ppt | 2 of 26 | None covers it |
| PFHxA | 3.5 ppt | 2 of 26 | None covers it |
Tested and not found
Below EPA’s minimum reporting level in every sample taken from Feb. 15, 2023 to Feb. 13, 2024. Not found means not measured above that level, which is not the same as zero.
All 25 compounds tested and not found
- 11Cl-PF3OUdS
- 4:2 FTS
- 6:2 FTS
- 8:2 FTS
- 9Cl-PF3ONS
- ADONA
- HFPO-DA (GenX)
- Lead
- NEtFOSAA
- NFDHA
- NMeFOSAA
- PFDA
- PFDoA
- PFEESA
- PFHpA
- PFHpS
- PFMBA
- PFMPA
- PFNA
- PFOA
- PFOS
- PFPeS
- PFTA
- PFTrDA
- PFUnA
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 | Oct. 1, 2025 to Dec. 31, 2025 | 0.084 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2025 to Sept. 30, 2025 | 0.081 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2018 to March 31, 2018 | 0.081 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2017 to Dec. 31, 2017 | 0.09 MG/L | Resolved |
| TTHM | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2017 to Sept. 30, 2017 | 0.095 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 cannot tell you
- Levels of everything else. Federal bulk data carries results for PFAS, lithium, lead and copper, and violations for the rest. Nitrate, arsenic, disinfection byproducts and other levels are in North Alamo WSC’s own annual report, which it must send you every year.
- 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.
- Anything after the latest data. SDWIS data is from 2026 Q2; UCMR 5 samples are from Feb. 15, 2023 to Feb. 13, 2024.
What to do next
Read up on Lithium
What each one does to health, where it comes from, and the certification claim that addresses it.
About LithiumGet the utility’s own report
North Alamo WSC must send you a water quality report every year. It lists nitrate, arsenic and byproduct levels this page cannot.
How to read itTest your own tap for lead
Your service line, solder and fixtures decide the lead at your faucet, not the utility’s average.
Lead in your water: what to doDecide if you want a filter at all
A filter for taste or chlorine is a preference, not a need. The standards say what each kind can do.
NSF/ANSI standards, decoded
Other Texas utilities
- City of Houston3 million
- San Antonio Water System2.6 million
- Dallas Water Utility1.4 million
- City of Austin Water & Wastewater1.1 million
- City of Fort Worth955,900
- El Paso Water Utilities747,168
- City of Arlington413,955
- City of Corpus Christi318,387
- City of Plano292,059
- Lubbock Public Water System275,041
- City of Irving264,546
- City of Laredo260,046
Sources
- EPA UCMR 5 occurrence data, file of Aug. 27, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q2
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.