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WaterSafeCheck

ZIP Code 78551 Water Quality Report

Harlingen, TX · Cameron County County

Safety Score
A

Water Safety Grade

Excellent — Meets all EPA standards

Health Violations

1

Total Violations

15

Lead Risk

N/A

Contaminants

1

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Active Water Quality Issues Detected

EPA records show 3 unresolved violations. Contact Harlingen Water Works System for current status.

About Tap Water in ZIP Code 78551

Tap water in ZIP code 78551 (Harlingen, TX) is among the safest in the country. Served by Harlingen Water Works System, this area earned a water safety grade of A with a composite score of 86/100 — indicating full regulatory compliance and low contaminant risk across EPA monitoring periods.

Water System

Harlingen Water Works System

EPA ID: TX0310002

Water Source

Surface Water

Population Served

85,900 residents

County

Cameron County County, Texas

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Lead Levels in ZIP 78551

EPA action level: 15 ppb | Public health goal: 0 ppb

Lead Level: 2.3 ppb — Very Low

The 90th percentile lead level in 78551 is 2.3 ppb, well below the EPA action level of 15 ppb. While this is a reassuring result, the EPA's public health goal for lead is actually zero — no amount of lead is considered completely safe, particularly for children under 6 and pregnant women. Running your tap for 30 seconds before use and using a certified NSF/ANSI 53 filter adds an extra layer of protection.
Lead Level (90th percentile)
2.30 ppb (0.0023 mg/L)
Lead Exposure Risk Rating
Unknown
Note: Lead levels above are the 90th percentile from EPA monitoring — meaning 90% of samples were at or below this level. Even "undetected" tap water lead doesn't account for lead leaching from home plumbing. If your home was built before 1986, individual tap testing is recommended.
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Violation History

Past 5 years — EPA SDWIS data

Harlingen Water Works System has recorded 1 health-based violation in the past 5 years. A single health violation means the water exceeded an EPA maximum contaminant level (MCL) at some point. Most water systems resolve these quickly, but residents should review the Consumer Confidence Report for details. 3 violations are currently unresolved — meaning the issue has not yet been formally corrected in EPA records. This is a serious concern that residents should follow up on with their water utility.

Total Violations (5 yr)
15
Health-Based Violations
1
Unresolved Violations
3
Boil Water Advisories
0
Compliance Risk
Critical

Regulatory compliance risk is rated Critical — the highest risk category. Harlingen Water Works System has an extensive history of unresolved violations and enforcement actions. Independent water testing is highly recommended.

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Contaminants Detected

Contaminants with health-based violations on record

EPA records identify 1 contaminant associated with health-based violations in ZIP code 78551: Stage 2 DBP Rule. These contaminants exceeded the Maximum Contaminant Levels (MCLs) established by the EPA under the Safe Drinking Water Act at some point in the 5-year monitoring period. The presence of these violations does not necessarily mean water is currently unsafe — water systems are often required to increase monitoring and treatment when violations occur. Review the annual Consumer Confidence Report for the most current status.

Stage 2 DBP Rule

⚖ Enforcement Actions

10 enforcement actions have been issued against Harlingen Water Works System — a high number that reflects sustained compliance struggles. Enforcement actions escalate from administrative orders to financial penalties when utilities repeatedly fail to meet safe drinking water standards.
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Water Source & Environmental Factors

Surface Water

This system draws water from lakes, rivers, or reservoirs. Surface water is treated to remove sediment, microorganisms, and chemical contaminants before reaching taps.

Water Source Type
Surface Water
CCR Source Classification
Surface Water
EPA Radon Zone

Lower potential

Zone 3

EPA Radon Zone 3 — lower radon potential, though the EPA still recommends testing all homes.

🛡 What Should You Do? — ZIP 78551 Recommendations

  • ✓ Run cold water for 30 seconds each morning before use — especially if pipes are old
  • ✓ Request your annual Consumer Confidence Report from Harlingen Water Works System
  • ✓ If your home was built before 1986, consider testing your own tap for lead
  • ✓ Use a pitcher filter (NSF/ANSI 42 certified) for improved taste

Frequently Asked Questions — ZIP 78551 Water Quality

Is tap water safe to drink in ZIP code 78551?+
Yes — tap water in 78551 (Harlingen, TX) currently meets all federal EPA standards with a water safety grade of A. No health-based violations are on record in the past 5 years. You can drink your tap water with confidence, though running the tap for 30 seconds in the morning is always a good practice.
What is the lead level in 78551 tap water?+
The 90th percentile lead level in 78551 is 2.3 ppb (parts per billion). The EPA action level is 15 ppb. This is a low level, well below the EPA action level of 15 ppb.
Who provides tap water to 78551?+
Tap water in ZIP code 78551 is provided by Harlingen Water Works System (EPA ID: TX0310002). This system serves approximately 85,900 residents. You can contact them directly for Consumer Confidence Reports, current advisories, and billing information.
What is the water source for 78551?+
ZIP code 78551 is served by surface water. Surface water systems draw from rivers, lakes, or reservoirs and must meet strict EPA treatment requirements including filtration and disinfection.
Does 78551 have any active water quality violations?+
Yes — there are currently 3 unresolved violations on record for this water system. Unresolved violations indicate issues that have not yet been formally corrected in EPA tracking systems. Contact Harlingen Water Works System for the latest update.
How do I get a copy of my water quality report for 78551?+
Your water utility — Harlingen Water Works System — is required by law to send you an annual Consumer Confidence Report (CCR) by July 1 each year. You can also request it directly from the utility or find it online by searching "Harlingen Water Works System Consumer Confidence Report." The EPA's ECHO database also has historical compliance data.
What water filter should I use in 78551?+
The right filter depends on what contaminants are present. For lead, look for a filter certified to NSF/ANSI Standard 53. For chlorine byproducts (like THMs), NSF/ANSI 42 filters work well. For a broad range of contaminants including PFAS, look for NSF/ANSI 58 (reverse osmosis) systems. For ZIP code 78551, with detected contaminants including Stage 2 DBP Rule, a multi-stage filter or reverse osmosis system is recommended.
Is 78551 tap water safe for babies and infants?+
Infants are especially vulnerable to lead, nitrates, and microbial contaminants in drinking water. Current EPA data for 78551 shows a lead level of 2.3 ppb — below the action level, but as an extra precaution, run your tap for 30 seconds before use and consider a certified lead filter for infant formula. Always consult your pediatrician for guidance specific to your child's health.

Data Sources & Methodology

Water quality data for ZIP code 78551 is compiled from the EPA Safe Drinking Water Information System (SDWIS), EPA ECHO enforcement database, UCMR5 unregulated contaminant monitoring, and Consumer Confidence Reports filed by Harlingen Water Works System. Safety scores are composite metrics derived from violation history, lead levels, enforcement actions, and infrastructure risk indicators. Data reflects a 5-year monitoring window. Last dataset update: 2024. View EPA source data →