Failing Water Quality
| Contaminant | Detected Level | EPA MCL | Health Guideline | Status |
|---|---|---|---|---|
| Lead |
25.4
|
15 ppb | 1 ppb | Exceeded |
| Copper |
6280.0
|
1300 ppb | 300 ppb | Exceeded |
| Compound | Level | EPA MCL | Health Guideline | Status |
|---|---|---|---|---|
| PFBA | 12.2 ppt | No standard | 500 ppt | Unregulated |
| PFPeA | 3.8 ppt | No standard | — | Unregulated |
| PFHxA | 3.5 ppt | No standard | 400 ppt | Unregulated |
| PFHxS | 3.4 ppt | 10 ppt | 10 ppt | Below limit |
| PFHxA | 3.3 ppt | No standard | 400 ppt | Unregulated |
| PFBS | 3.0 ppt | 2000 ppt | 100 ppt | Below limit |
Water Quality Summary
Tap water quality in Mercedes, Texas (78570) receives an overall grade of F (Failing) with a score of 30 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is 38 points below the Texas state average of 68. Compared to the national average (75), this area scores significantly lower. The area is served by 4 water systems providing water to approximately 189,053 people, using surface water sources. Testing has found elevated levels of Lead, Copper that warrant attention. PFAS testing detected 6 compounds, all currently below EPA limits. Over the past 5 years, water systems here have accumulated 113 violations, including 5 health-based violations.
A score of 30/100 indicates serious water quality failures in Mercedes, TX. The water system has significant violations, contaminant exceedances, or enforcement actions. Residents should strongly consider using a certified water filtration system for drinking and cooking water, requesting their utility's latest test results, and potentially having their water independently tested.
Health Information
Lead is a toxic metal that can leach from aging pipes and plumbing fixtures.
Even low levels of lead exposure can cause developmental delays in children, kidney damage, and cardiovascular effects in adults. The EPA action level is 15 ppb, but health experts recommend no safe level of lead in drinking water.
Lead enters water primarily through corrosion of lead service lines, lead solder, and brass fixtures — especially in homes built before 1986.
If lead is detected above 1 ppb, consider using a certified lead-removal filter (NSF/ANSI 53) for drinking and cooking water. Run cold water for 30 seconds before use if water has been sitting in pipes.
Copper can leach into water from copper plumbing, especially in newer homes or when water is acidic.
Short-term exposure above 1,300 ppb can cause gastrointestinal distress. Long-term exposure may cause liver or kidney damage. People with Wilson's disease are especially vulnerable.
Copper pipes, fittings, and faucets are the most common source. Corrosive (low-pH) water accelerates copper leaching.
If copper levels are elevated, flush pipes by running water for 15–30 seconds before use. Reverse osmosis and distillation systems effectively remove copper.
Common Questions
Tap water in Mercedes, Texas receives a grade of F (Failing) with a score of 30/100. This indicates significant water quality concerns based on violation history, contaminant levels, or enforcement actions. We recommend reviewing the specific contaminants detected below and considering a certified water filter.
ZIP code 78570 is served by 4 water systems using surface water sources, providing water to approximately 189,053 people. Surface water systems are more susceptible to contamination from agricultural runoff, industrial discharge, and weather events, but typically undergo more extensive treatment including filtration and disinfection.
Yes — lead levels in Mercedes, Texas are 25.4 ppb, which exceeds the EPA action level of 15 ppb. This is a serious concern. We strongly recommend using a certified lead-removal filter for all drinking and cooking water, and having your water independently tested.
6 PFAS compounds were detected in water serving Mercedes, Texas, but all are currently below EPA limits. While levels are within regulatory standards, some health organizations recommend minimizing any PFAS exposure. Activated carbon or reverse osmosis filters can reduce PFAS levels.
Water systems serving Mercedes, Texas have received 113 violations in the last 5 years, including 5 health-based violations. Violations can range from paperwork issues (monitoring & reporting) to serious health-based violations where contaminant levels exceeded safe limits. Review the violation details above for specifics.
Based on detected contaminants (lead, PFAS, copper), residents in Mercedes, Texas should consider: Reverse osmosis (RO) system — most effective for PFAS, lead, and other contaminants. Always look for filters with NSF/ANSI certification for the specific contaminants you want to remove.