The Power of Information

National Drinking Water Database


Zapata County Wcid Hwy 16 East - Lopeno, TX


Serves 35 people - Test data available: 2004-2007

This drinking water quality report shows results of tests conducted by the water utility and provided to the Environmental Working Group (EWG) by the Texas Commission on Environmental Quality . It is part of EWG's national database that includes 47,667 drinking water utilities and 20 million test results. Water utilities nationwide detected more than 300 pollutants between 2004 and 2009. More than half of these chemicals are unregulated, legal in any amount. Despite this widespread contamination, the federal government invests few resources to protecting rivers, reservoirs, and groundwater from pollution in the first place. The information below summarizes test results for this utility and lists potential health concerns.

 
This Drinking Water System
National Average
Exceed Health GuidelinesTests showing chemicals at concentrations above health guidelines established by federal and state health agencies. These guidelines are typically set at a levels that pose no significant health risk.
9 chemicals
4
Health Standard ExceedencesChemicals detected at concentrations above the legal limit, the Maximum Contaminant Level (MCLs) established by the U.S. EPA. Most MCLs are based on annual averages, so exceeding the MCL for one test does not necessarily indicate that the system is out of compliance.
5 chemicals
0.5
Pollutants FoundThe total number of contaminants detected since 2004, according to data provided by the state water agency.
14 chemicals
8
Tests ConductedThe total number of number of water quality tests conducted by water utilities and recorded in data provided by the state water agency.
206 tests
420

Contaminants Exceeding Health Guidelines

ContaminantAverage/
Maximum
Result
Health Limit
Exceeded
Legal Limit
Exceeded

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
Total trihalomethanes (TTHMs)Total trihalomethanes constitute the sum of four disinfection byproducts: chloroform, bromodichloromethane, dibromochloromethane, and bromoform.148.82 ppb
229.6 ppb
Yes
9.8 ppb
Yes
80 ppb
Monochloroacetic acidMonochloroacetic acid is a disinfection byproduct regulated by EPA as one of five haloacetic acids that are formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.47.83 ppb
166.1 ppb
Yes
70 ppb
Yes
60 ppb
ChloroformChloroform is a disinfection byproduct from the trihalomethane (THM) family, and is formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.59.71 ppb
119.1 ppb
Yes
5.7 ppb
Yes
80 ppb
Dichloroacetic acidDichloroacetic acid is a disinfection byproduct regulated by EPA as one of five haloacetic acids that are formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.39.57 ppb
74.2 ppb
Yes
MCLGA non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.: 0 ppb
Yes
60 ppb
Total haloacetic acids (HAAs)Total haloacetic acids refers to the sum of the concentrations of five related disinfection byproducts in a water sample: dichloroacetic acid, trichloroacetic acid, monochloroacetic acid, monobromoacetic acid and dibromoacetic acid.116.6 ppb
116.6 ppb
Yes
0.7 ppb
Yes
60 ppb
BromoformBromoform is a disinfection byproduct from the trihalomethane (THM) family, and is formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.9.06 ppb
23.4 ppb
Yes
MCLGA non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.: 0 ppb
No
80 ppb
BromodichloromethaneBromodichloromethane is a disinfection byproduct from the trihalomethane (THM) family, and is formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.48.39 ppb
74.9 ppb
Yes
MCLGA non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.: 0 ppb
No
80 ppb
DibromochloromethaneDibromochloromethane is a disinfection byproduct from the trihalomethane (THM) family, and is formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.39.12 ppb
59.7 ppb
Yes
0.4 ppb
No
80 ppb
Trichloroacetic acidTrichloroacetic acid is a disinfection byproduct regulated by EPA as one of five haloacetic acids that are formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.11.55 ppb
21.3 ppb
Yes
20 ppb
No
60 ppb
NOTE: Each dot in the above graph represents one month.
* Water utilities are noted as exceeding the legal limit if any test is above the maximum contaminant level (MCL). Most MCLs are based on annual averages so exceeding the MCL for one test does not necessarily indicate that the system is out of compliance.

Other Detected Contaminants

ContaminantAverage/
Maximum
Result
Health Limit
Exceeded
Legal Limit
Exceeded

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
Dibromoacetic acidDibromoacetic acid is a disinfection byproduct regulated by EPA as one of five haloacetic acids that are formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.15.48 ppb
27.3 ppb
NoNo
60 ppb
Bromochloroacetic acidBromochloroacetic acid is a disinfection byproduct, and is formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.23.45 ppb
34.8 ppb
NoLegal at any levelThis is the Federal Limit. State Limits may be lower.
Monobromoacetic acidMonobromoacetic acid is a disinfection byproduct regulated by EPA as one of five haloacetic acids that are formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.1.11 ppb
5.9 ppb
NoNo
60 ppb
NitrateNitrate enters drinking water sources from fertilizer runoff, leaching septic tanks, and erosion of natural deposits; it is also emitted by chemical, petrochemical and metal-finishing industries.0.25 ppm
0.25 ppm
No
10 ppm
No
10 ppm
DalaponDalapon is an herbicide used on roads, railway tracks and other rights of way.3.4 ppb
3.4 ppb
No
200 ppb
No
200 ppb
NOTE: Each dot in the above graph represents one month.
* Water utilities are noted as exceeding the legal limit if any test is above the maximum contaminant level (MCL). Most MCLs are based on annual averages so exceeding the MCL for one test does not necessarily indicate that the system is out of compliance.

Contaminants Not Detected - 1 chemicals

Nitrite

Pollution Summary

14Total Contaminants Detected (2004 - 2007)

Nitrate, Dalapon, Monochloroacetic acid, Dichloroacetic acid, Trichloroacetic acid, Monobromoacetic acid, Dibromoacetic acid, Bromochloroacetic acid, Total haloacetic acids (HAAs), Chloroform, Bromoform, Bromodichloromethane, Dibromochloromethane, Total trihalomethanes (TTHMs)

2Agricultural Pollutants
(pesticides, fertilizer, factory farms)

Nitrate, Dalapon

2Sprawl and Urban Pollutants
(road runoff, lawn pesticides, human waste)

Nitrate, Dalapon

1Industrial Pollutants

Nitrate

12Water Treatment and Distribution Byproducts
(pipes and fixtures, treatment chemicals and byproducts)

Monochloroacetic acid, Dichloroacetic acid, Trichloroacetic acid, Monobromoacetic acid, Dibromoacetic acid, Bromochloroacetic acid, Total haloacetic acids (HAAs), Chloroform, Bromoform, Bromodichloromethane, Dibromochloromethane, Total trihalomethanes (TTHMs)

1Naturally Occurring
(naturally present but increased for lands denuded by sprawl, agriculture, or industrial development)

Nitrate

1Unregulated Contaminants
EPA has not established a maximum legal limit in tapwater for these contaminants

Bromochloroacetic acid

EPA Violation Summary

Violation CategoryNumber of Violations
MCL and Treatment
(click see violations)
24

Information on violations is drawn directly from EPA's national violations database in the Agency's Safe Drinking Water Information System. Analyses by others have raised questions about the quality of the information in EPA's database. For the purposes of this investigation, EWG is not showing below or including in our analyses, those violations for individual water suppliers that occurred on days for which the total number of violations assigned by EPA to that water supplier was greater than 20. This criteria was based on common characteristics of incorrect violations data as identified by water utilities, from a review of EPA's violations data by several hundred utilities prior to the release of EWG's investigation.