Is Weslaco, TX tap water safe?

Data: U.S. EPA · How we read the data · How we check it

No federal limits exceeded in EPA data for North Alamo Water Supply Corporation. 5 PFAS were detected below the limits.

3 public water systems serve parts of Weslaco. The largest, North Alamo Water Supply Corporation, serves 171,195 people. Your water bill names your system.

Largest system

North Alamo Water Supply Corporation

171,195 people · Surface water · EPA ID TX1080029

Buys treated water from City of Weslaco, City of Edinburg, City of Mercedes, City of Raymondville.

PFAS	Highest average	Limit	Status
PFOA Not detected	–	4 ppt	Not detected
PFOS Not detected	–	4 ppt	Not detected
PFHxS Detected, below limit	0.85 ppt	10 ppt	Detected, below limit
PFNA Not detected	–	10 ppt	Not detected
HFPO-DA (GenX) Not detected	–	10 ppt	Not detected

ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.

Lead: 0.32 ppb at the 90th percentile (Nov 2026, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 5

Full North Alamo Water Supply Corporation results

Across Texas, 28 of 1,130 water systems EPA tested had PFAS above a 2024 federal limit, and 13 systems were above the lead action level in results from the last five years. Texas results.

Weslaco homes and lead pipes

25%

of homes built before 1980 (Texas 33%, US 50%)

built before 1950 (Texas 6%)

44%

of households rent (Texas 37%)

Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. Renting? Ask your landlord what the service line is made of, because it's their pipe to replace. How to check your own line.

Housing: Census American Community Survey 2020–2024 5-year estimates for Weslaco city (tables B25034, B25003). Estimates for small places have a margin of error.

Other water systems serving Weslaco

City of Weslaco
40,033 people · Surface water · Texas · lists this city
PFOS detectedAlso: PFHxS detected · Lithium above screening level · 1 health-based violation since 2016
Trails End Mobile Home Park Water System
200 people · Purchased surface water · Texas · reported ZIPs here
Not in EPA's PFAS sample

How nearby cities compare

City	Main water system	PFAS	Lead (90th pct.)
San Juan 10 mi North Alamo Water Supply Corporation	North Alamo Water Supply Corporation	None above limits	0.32 ppb
Pharr 13 mi City of Pharr	City of Pharr	None above limits	1.09 ppb
Edinburg 16 mi City of Edinburg	City of Edinburg	None above limits	0 ppb
McAllen 17 mi McAllen Public Utility	McAllen Public Utility	None above limits	2.3 ppb
Harlingen 18 mi Harlingen Water Works System	Harlingen Water Works System	None above limits	0 ppb
Mission 21 mi City of Mission	City of Mission	None above limits	1.83 ppb

Weslaco ZIP codes (1)

78596

Questions

Is Weslaco tap water safe to drink?

North Alamo Water Supply Corporation had 5 health-based violations since 2016. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.

Who supplies water in Weslaco, TX?

3 public water systems serve parts of Weslaco. The largest is North Alamo Water Supply Corporation (171,195 people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.

Does Weslaco tap water have PFAS?

North Alamo Water Supply Corporation had 5 PFAS detected at least once in EPA's 2023–2025 testing, all with averages below the federal limits.

Do Weslaco homes have lead pipes?

Census estimates put 25% of Weslaco homes as built before 1980 (Texas: 33%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. North Alamo Water Supply Corporation's service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.

Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.