Missouri State University

Melida Gutierrez

  • Professor of geology
  • Springfield, Missouri
  • PhD, Geohydrology, University of Texas at El Paso

Trouble under the surface

Crystal clear water: It quenches thirst, cleanses and sustains life.

Approximately 71 percent of the Earth’s surface is covered in water, and 96.5 percent of it is in the oceans.

The other 3.5 percent of the water supply fills lakes, streams, ponds and aquifers; forms icecaps and glaciers; and evaporates or exists inside lifeforms — like us.

The other 3.5 percent

No one really knows how long the water supply will last, according to Dr. Melida Gutierrez, professor of geology at Missouri State University. It’s a question she gets asked frequently as she presents at international conferences.

Though the quantity is a concern, Gutierrez is most focused on the quality of this valuable resource. 

For her two primary projects, she’s selected two areas she calls home: southwest Missouri and Chihuahua, Mexico.

Arsenic in water

The river Gutierrez studies in northern Mexico, Rio Conchos, was said to contain high levels of arsenic.

She collaborated with her colleagues from the University of Chihuahua, who collected hundreds of water samples. The team works for months calibrating the sampling containers and instruments and meeting with the local farmers to explain the process and gain access to the wells.

The sampling and initial analysis must be completed quickly since the samples are reliable for no more than three weeks. 

Contaminants were revealed in the samples, though not to the toxic level that had been previously described and feared.

“I started looking at the river and how it changes quality downstream. Then I thought about the sediment, so I tested that,” she said. “It’s a trick of chemistry to know what to sample. The sediment traps the contaminants.”

After sampling and testing the sediments, they began seeing the interconnection with the groundwater and began a round of tests with the groundwater.

In this case, Gutierrez found the cause of the contamination was natural.

“That’s part of being a scientist — that you see an interconnection — things that you might think are very separate,” she said. “All of a sudden you find that one causes the other one or they’re interconnected somehow.”

The flow of information

Gutierrez publishes the results in a multitude of ways, from top-tier academic journals in English and Spanish to more accessible publications, like farming magazines.

The flow of information isn’t as free in Mexico, Gutierrez noted, and she sees it causing a severe lack of trust.

“Some colleagues who work for the government must report only things the government wants to hear,” Gutierrez said.

Since the people of Chihuahua depend completely upon groundwater for drinking, they’re concerned about the dropping reserve. Because of this, she said, many take more water than they need.

“It’s like going to a doctor and the doctor doesn’t tell you what you have,” she said. “You’re feeling bad, then you start fearing the worst. That’s how the farmers are: They are fearing the worst and making it come true.”

The water table is dropping, according to Gutierrez’s colleagues, but there is not a system in place for monitoring wells. 

“In Missouri, we have monitoring wells. I can go online and check what the level is and what it was last month and compare it to last year. The information is available and free. They don’t have that,” she said.

A dirty job to find clarity

Gutierrez involves her students in her research, in her sediment collection and studies in Aurora, Missouri.

The students collected hundreds of pounds of sediment and laid the samples on laboratory work tables to air dry. Next, they sieved the samples to remove all particles larger than two millimeters. Then they bagged the sediment — five grams at a time — and shipped the samples to a commercial lab in Reno, Nevada, for initial analysis.

They were testing for zinc, in part due to the history of zinc and lead mining in Missouri. It is extremely toxic when paired with cadmium, another heavy metal sometimes associated with mining waste. 

The team tested the groundwater samples and found a very limited area where contamination existed. 

“We have one sample with a lot of zinc right next to one that has very little, so you want to make sure,” she said.

Since Missouri is known for its abundance of outdoor activities like hiking, fishing, canoeing and camping, Gutierrez highlights the effects on natural habitats in order to elevate her students’ interests in chemistry.

She is quite proud of the ownership her undergraduate students take.

“You work on something different. Everyone looks at it from a different perspective, so you get better,” she said.