Tap Water Results

Is San Juan, TX tap water safe?

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

Summary

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

2 public water systems serve parts of San Juan. 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.

PFASHighest averageLimitStatus
PFOA
Not detected
–4 pptNot detected
PFOS
Not detected
–4 pptNot detected
PFHxS
Detected, below limit
0.85 ppt10 pptDetected, below limit
PFNA
Not detected
–10 pptNot detected
HFPO-DA (GenX)
Not detected
–10 pptNot 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.

San Juan homes and lead pipes

18%
of homes built before 1980 (Texas 33%, US 50%)
1%
built before 1950 (Texas 6%)
20%
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. How to check your own line.

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

Other water systems serving San Juan

  • City of San Juan
    30,000 people · Surface water · Texas · lists this city
    PFOS detectedAlso: PFHxS detected · Lithium above screening level

How nearby cities compare

CityMain water systemPFASLead (90th pct.)
Pharr 3 mi
City of Pharr
City of PharrNone above limits1.09 ppb
McAllen 6 mi
McAllen Public Utility
McAllen Public UtilityNone above limits2.3 ppb
Edinburg 9 mi
City of Edinburg
City of EdinburgNone above limits0 ppb
Weslaco 10 mi
North Alamo Water Supply Corporation
North Alamo Water Supply CorporationNone above limits0.32 ppb
Mission 11 mi
City of Mission
City of MissionNone above limits1.83 ppb
Harlingen 28 mi
Harlingen Water Works System
Harlingen Water Works SystemNone above limits0 ppb
San Juan ZIP codes (1)
  • 78589

Questions

Is San Juan 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 San Juan, TX?

2 public water systems serve parts of San Juan. 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 San Juan 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 San Juan homes have lead pipes?

Census estimates put 18% of San Juan 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.