Category: March 2019

Gaurav Jha is a PhD student in the NMSU Department of Plant and Environmental Sciences, and he anticipates completing his studies in Spring 2020. Gaurav is also the recipient of a 2018 NM WRRI Research Grant for a project entitled: Speciation of metal(loids) in agricultural field soils impacted by Animas/San Juan River after the 2015 Gold King Mine Spill. In this effort, Gaurav is collaborating with his faculty advisors, April Ulery and Kevin Lombard, also of the Department of Plant and Environmental Sciences.

On August 5, 2015, three million gallons of acidic, metal-laden water were accidentally released into the Animas River from the Gold King Mine (GKM). Some of the metal burden carried by the Animas and San Juan Rivers to the irrigation ditches and into the fields has become incorporated into the soil matrix over time. Large areas of the affected watershed also happen to lie in the Navajo Nation. It is clearly important to learn to what extent this metal contamination constitutes a toxic hazard to plants and the environment generally. The primary goal of the project is therefore to determine representative concentrations of the various relevant metals in irrigation ditch sediments and/or field soils irrigated by Animas River water, and to estimate thereby the toxic impact of the contamination.

The total concentrations of nine elements, including arsenic, lead, manganese, iron, copper, calcium, zinc, aluminum, and chromium, have been measured in the irrigation ditches and fields for two growing seasons. Arsenic exceeded the NM Environmental Department recommended soil concentrations at some locations in the alfalfa and vegetable fields. These values were established and recorded at sampling points using a Field Portable X-Ray Fluorescence (PXRF) spectrophotometer. The set of values obtained were then interpolated to provide a surface area density map of concentrations. These metal(loid)s may be present in the soil in different forms or species that have varying toxicity or bioavailability. Various physicochemical processes, such as ion exchange, surface complexation, and precipitation mechanisms, contribute to the availability and toxicity of the different metal species that are present. These mechanisms in turn are influenced by clay and organic matter content, pH, oxidation state changes, and concentration. Metals found in the water-soluble and exchangeable fractions are most likely to be available to the plants, and could be toxic if taken up and stored in the plant tissue. Metals bound on carbonates, oxide minerals or organic matter tend to be less available to plants, and so may not pose a problem even if their total concentration is high.

A few encouraging preliminary findings include the fact that the higher concentrations of arsenic that were found in some hotspots have not correlated to increased concentration of metal uptake in plants; and also the concentrations of metals in fruits and vegetables have so far been found to be below the upper tolerable limits specified by the Food and Nutrition Board of the National Institute of Health, and are therefore safe for consumption.

Gaurav will prepare a final report for the project in May, which will be posted on the NM WRRI website. He has presented his research findings at several meetings including the annual Animas and San Juan Watersheds Conference held each year in Farmington.

In January 2019, Gaurav attended the International Conference on Soils Across Latitudes organized by the Soil Science Society of America in collaboration with the Canadian and Mexican Societies of Soil Science. He received first place for his five-minute rapid oral presentation and poster presentation by the Soil and Environmental Quality Division. He also was recognized by the Society for his research excellence and was selected as one of the top ten student research finalists for society-wide presentations. In New Mexico, Gaurav has presented his research and answered questions on three radio talk shows and at 16 Teach-Ins at various Navajo Nation Chapterhouses.

Gaurav recently indicated that the NM WRRI student grant allowed him to become more familiar with metal behavior in soils. Also, the grant afforded him a learning experience in carrying out a grant project including how to spend the funding most effectively. After receiving his PhD, Gaurav wants to continue to conduct research as a post-doc. Eventually, he wants to be involved in university research and teaching.

By Victoria Pena-Parr, University of New Mexico Communication & Marketing

University of New Mexico graduate student Jon Golla conducts his research along the Jemez River in the natural laboratory of the Valles Caldera located in northern New Mexico. Golla’s research focuses on his passions involving aqueous geochemistry and geothermal systems.

His scientific interests stem from an unfamiliarity with potable water during his childhood and from an early exposure to geothermal energy in the Philippines, so the opportunity to work on the waters associated with the Valles Caldera Geothermal System was part of what drew him to graduate study at UNM. Through this research, Golla is gaining a better understanding of the proximal and distal hydrogeologic influences of Valles Geothermal System on the upper Jemez River.

He received a $6,000 grant to help fund his research titled, Surface Water Quality Implications of Valles Caldera Geothermal Fluids on Jemez Watershed: A Holistic Hydrogeochemical Investigation as part of the Student Water Research Grants program through the New Mexico Water Resources Research Institute (NM WRRI).

“Known as New Mexico’s version of Yellowstone, the Valles Caldera is a highly mineralized geothermal system, which are known for usually having a significant environmental footprint,” Golla said. “The Jemez Mountains are well-known for its world-class, high temperature, liquid-dominated Valles Caldera Geothermal system. The Valles Caldera Geothermal system is what gives the Jemez Hot Springs their natural heat. These geothermal fluids find their way into the Jemez River.”

Golla specifically focuses on the natural trace element salinization of the Jemez River. Shallow magmatic activity provides heat to the system and creates a natural convection current of geothermal waters, which are usually mixtures of deeply derived fluids and infiltrating precipitation. These circulating fluids become much more saline than other natural waters (i.e., river, groundwater, etc.) because minerals in rocks are more readily dissolved at higher temperatures. Such saline waters are expressed at the surface of the iconic Soda Dam and Jemez Springs as springs, which discharge into and impair the water quality of the Jemez River.

His research goals as part of the project include discovering how these dissolved species are introduced into the system, which is marked by elevated concentrations in the river; how far downstream this geothermal signature is carried; and which processes (i.e., dissolved species captured by or transformed into solids) are potentially responsible for removal in-stream. The research group collects multiple water samples along the study reach to provide a continuous spatial mapping of geochemical behavior.

“We are measuring and assessing concentrations of heavy metals (arsenic, uranium, lead, etc.) that only require trace exposure to induce adverse health effects and are usually not regularly analyzed in routine water quality surveys,” Golla said. “Most importantly, water from the Jemez River is used by stakeholders, including Jemez and Zia Pueblos, for domestic, recreational, and irrigational uses.”

Golla’s research builds upon previous knowledge published by Los Alamos National Laboratory scientists and extends the suite of measured dissolved elemental species by including metals (like arsenic, lead, and uranium), which are usually found in trace amounts in natural waters but are more abundant in the inflowing thermal spring waters due to enhanced water-rock interaction at depth.

“This work is confirming the significant role that groundwater contributions to surface water plays in affecting water quality,” added UNM Department of Earth and Planetary Sciences Professor Laura Crossey, Golla’s advisor. “As we look to a future with potential decreases in snowmelt, it may be that these groundwater contributions cause our rivers to become more saline and impair their use. Studies such as Jon’s can help improve our prediction of water quality as we improve our climate-based forecast models for water quantity, both critical factors for water management in our semi-arid region.”

This study also supplements the New Mexico Environment Department’s recently approved Total Maximum Daily Load development and the U.S. Environmental Protection Agency’s ongoing New Mexico Water Quality Management Plan.

“Personally, I think New Mexico is very lucky to have a world-class geothermal system,” Golla said. “Due to its relatively undisturbed state, the Valles Caldera is a natural laboratory to study continental hydrothermal processes.”

By Catherine Ortega Klett, NM WRRI Program Manager

In 2017, Dr. Saeed Langarudi arrived at New Mexico State University after receiving his PhD in system dynamics and economics from Worcester Polytechnic Institute in Worcester, Massachusetts. His dissertation was entitled, A System Dynamics Approach to Political Economy of Resource Dependent Nations. He also has an MSc in economics from Isfahan University of Technology, Isfahan, Iran, and a BSc in industrial engineering from Aza University of Najafabad.

Dr. Langarudi’s research interests include natural resources economics, socioeconomic development, political economy, behavioral decision-making, system dynamics, and dynamics of conflict and security. At NMSU, he is teaching a graduate course, System Dynamics for Understanding Economics and Natural Resource Management.

Over the past couple of years, Dr. Langarudi has worked with colleagues at the New Mexico Water Resources Research Institute on several research projects including participating on a U.S. Bureau of Reclamation grant. He is working with a team to identify and examine the significance of dynamic interactions and feedback mechanisms within and between hydrology, human decision processes, and socioeconomic systems. His research will inform natural resources managers and policy makers to design high-leverage interventions that potentially revive the balance of our socioenvironmental systems.

Dr. Langarudi is also working on a National Science Foundation INFEWS (Innovations at the Nexus of Food, Energy, and Water Systems) program. In this project, he is responsible for system dynamics modeling of interrelationships between hydrology and agriculture, and hydrology and energy systems. In this regard, he collaborates with a group of scholars from different disciplines including economics, animal sciences, range sciences, hydrology, and energy. Dr. Langarudi’s interdisciplinary work has appeared in prestigious journals such as Ecological Economics and Systems.

Dr. Langarudi is an active member of multiple systems sciences communities. He chairs the Security Thread of the International Conference of the System Dynamics Society. He is also a committee member in the Computational Social Science Society of the Americas as well as in the Iranian System Dynamics Society.