McAllen, Texas

McAllen, Texas McAllen, Texas

Water Quality in McAllen, Texas

Watershed: Llano Grande Lake – Arroyo Colorado

What is the water quality like in McAllen, TX?

Let’s dive deeper into what’s in McAllen water.

What’s in McAllen water?

Here are the top 6 chemical compounds in your water and what health issues they can potentially cause:

  1. Arsenic – Potential effect: Cancer
  2. Bromodichloromethane – Potential effect: Cancer
  3. Chlorite – Potential effect: Change in blood chemistry
  4. Haloacetic acids – Potential effect: Cancer
  5. Radium – Potential effect: Cancer
  6. Total trihalomethanes – Potential effect: Cancer

These are six of the 30 contaminants analyzed by the Environmental Working Group (

15 of these contaminants are rated as exceeding EWG Health Guidelines.

See the What Can You Do? section below for all of the contaminants you can filter out and how to do it.

Where does McAllen’s water come from?

McAllen’s water comes from the Llano Grande Lake – Arroyo Colorado watershed.

6 of the 7 EPA assessed water sources in the Llano Grande Lake – Arroyo Colorado watershed are in Impaired or Unknown condition. These include:

  • Arroyo Colorado – two segments
  • Donna Reservoir
  • Drainage ditches flowing into Arroyo Colorado
  • Drainage ditches flowing into Lower Laguna Madre

Ideally, a water source would be rated in Good condition.

Whether a water source is in Impaired or Good condition refers to the quality of these uses:

  1. Drinking Water
  2. Aquatic Life
  3. Fish and Shellfish Consumption
  4. Recreation

Learn more from How’s My Waterway

See below for what you can do to improve McAllen’s water.

Conclusion – What Can You Do?

Information about water quality can be surprising.

But there’s no reason to lose hope. There are things you can do in your household as well as things you can do at a community level.

In Your Household:

*Chlorination is an effective method of disinfecting/treating drinking water. You can then use a water filter to reduce the effects of chlorination byproducts to get the safest, cleanest water possible.

In Your Community:

Contact your local government officials and put pressure on them to invest in cleaner waterways and upgraded city water filtration and treatment.

Go to: to find contact information for your local officials.

Water Quality in Other Texas Cities

Texas Water Quality Page

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