Communities, tribes, federal agencies, and other stakeholders in southwestern Colorado have organized to better understand the threat of mercury contamination to their reservoirs. Joe Ryan, PhD, professor of environmental engineering, and his students from CU-Boulder’s Civil, Environmental, and Architectural Engineering have been working over the past few years to help augment these efforts in assessing the sources, deposition, and risks of mercury in this region in conjunction with the Mountain Studies Institute in Silverton, the Southern Ute Tribe’s Environmental Programs Division, and the Pine River Watershed Group.
Over the past decade, five major reservoirs in southwestern Colorado have been added to the list of Colorado waters with fish consumption advisories that place limits on the number of fish caught in these waters to be eaten due to mercury contamination. Mercury accumulates in the fatty tissues of fish, and humans are exposed to mercury primarily by eating these fish. Exposure to even small amounts of mercury can result in serious neurological damage and death, especially for fetuses, infants, and children.
There are several ways that mercury can be introduced into the environment. One of the major sources is the combustion of coal. Across the United States, coal-burning power plants emit about 50 tons of mercury each year. Five major coal-burning power plants are currently located upwind of southwestern Colorado due to the abundance of coal in this area. Another potential source of mercury is abandoned mines, which are abundant in the mountains around Durango and Silverton. In the early days of mining, mercury was used in the amalgamation of gold and other precious metals. In mining, mercury was used in the elemental, liquid form and tends to remain in the vicinity of the mines.
Recent forest fires are suspected of causing the release of mercury into the atmosphere, but not all of the mercury in forest soils is volatilized – some remains in the forest soils. Forest fires exacerbate erosion of hillside soils, and the eroded soils carry mercury to the water bodies.
A modest grant from the CU-Boulder Outreach Committee allowed Professor Ryan and his students to start work on the project in southwestern Colorado, which eventually led to additional funding support from the National Science Foundation (NSF). Doctoral student Jackson Webster was recruited to the university through the NSF funding to help with the research project.
Webster recently received the National Parks Service George Melendez Wright Climate Change Fellowship for his research into mercury contamination. This student fellowship program supports new and innovative research on climate change impacts to protected areas and to increase the use of scientific knowledge to further resource management in parks.
Webster is studying the distribution of mercury from forest soils following wildfires in Mesa Verde National Park in southwestern Colorado. He was selected as one of twenty recipients nationally and received funding to assess the effect of fire and mercury levels within the national park. Webster is looking at the results of fire over the past three decades and the possibility that wildfire frequency and severity might increase with ongoing climate change in the southwestern United States. Webster started with sampling soil this past summer and will conduct follow-up analysis over a period of 15 months with the help of Professor Ryan, two other engineering students, and the science staff at Mesa Verde.
The research being conducted in the southwestern part of the state is one of several projects Professor Ryan and his students are involved with that brings the educational and scientific resources of the university to the citizens across Colorado. Ryan’s outreach work is directly linked to his teaching and research, which allows his students to gain valuable field experience and inform their own educational pursuits.
For more information visit the Mercury Contamination in Southwest Colorado program page.