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CURRENT PROJECTS |
| The Gunnison Basin Selenium Task Force has received funding from several Environmental Protection Agency (EPA) 319 Grants to study elevated selenium concentrations in the surface waters of the Gunnison and Uncompahgre River basins. Current projects are focused on characterizing the sources of the problem, and developing solutions that are economically and environmentally sustainable for the region. |
1. PHYTOREMEDIATION PROJECT Completed FINAL REPORT
Project Goal: The goal of this project was to demonstrate the feasibility of using selected agricultural crops and trees with economic value to remove selenium from soils and water, thereby reducing selenium loading from irrigated lands, to underground drainage waters, and intimately, to water of the Uncompahgre and Gunnison Rivers.
Developed on behalf of the Gunnison Basin Selenium Task Force, and administered by the Shavano Soil Conservation District, this
four-year experiment was designed to test the ability of certain crops to pull selenium out of the ground. Studies in other areas of the country with high selenium soils have shown that in addition to native species, certain agronomic crops naturally accumulate selenium at high levels in their plant parts, or even release some selenium to the atmosphere as a non-toxic gas.
Selenium removed by phytoremediation, is selenium that is not available for leaching by irrigation water into the groundwater and river system. This is good news for the rivers and creeks of the Uncompahgre Valley - some of which have highly elevated concentrations of selenium. This is also good news for the birds and fish of the area, which may develop reproductive problems and even deformities as a result of these high selenium levels.
Located on the Meaker Farm just north of Montrose, the first phytoremediation test plots were established. Over 4,000 poplar trees of three different varieties were planted. In addition, a fescue/birdsfoot trefoil mix, canola, and kenaf (a fast-growing annual tree), were started. At a field day held on July 18, 2001, organized by CSU Cooperative Extension and the local NRCS offices, interested individuals were able to come out and view the phytoremediation plots. The trees, just three months after planting, were almost three feet tall, and the canola had already gone to seed.
CSU Extension Field Day - poplar test plots
CSU Extension Field Day - Fred Fisher in front of kenaf and canola test plots
As the crops mature, samples of their roots, shoots, and if necessary, seeds, will be collected, cleaned, and prepared for selenium analysis at the lab. Samples will also be collected to evaluate selenium concentrations in the surrounding soils, groundwater, and surface water. In this way, scientists hope to develop an understanding of how effective these crops may be in reducing overall selenium concentrations in nearby waterways.
An important component of local selenium reductions may also be related to reducing the amount of irrigation water applied to the crops, thereby limiting the amount of deep percolation water that seeps from these fields. After the first two years of establishment, the poplars in particular will be able to access the relatively shallow groundwater table in the area. For sale of poplars to chipboard or other commercial buyers, it is estimated that six to seven years of growth are needed to reach a suitable caliper. Over this period, their reduced need for irrigation may add up to significant reductions in the amount of selenium flushed from deeper soils into the river system.
2. GUNNISON AND UNCOMPAHGRE RIVER SELENIUM TARGETING GRANT
This project is designed to gather water quality data necessary to characterize the selenium loads that are being contributed from various sources within these watersheds. This includes the collection of soil and water quality samples from areas that have historically proven to have high selenium concentrations. Evaluation of the variability of selenium loading in the basins will guide the implementation of Best Management Practices (BMPs) for land owners, municipalities, and agricultural producers in the area, and will provide insight on how current land use practices affect selenium loading into the local waterways.
In addition to identifying the local sources of selenium loading, the project also is developing an educational outreach program for land users in the area, addressing the selenium problem. Issues of concern include:
- Potential impacts of selenium pollution on local fish and aquatic birds;
- Potential changes in land use practices, and the resultant economic, environmental, and social impacts; and,
- What can be done to reduce selenium loading into the local rivers to improve water quality.
3. EFFECTS OF CHANGES IN LAND USE ON SELENIUM LOADING IN THE
WHITEWATER, CO AREA
Historically, land use in the Kannah Creek, Whitewater Creek, and Callow Creek basins has been generally limited to open range and irrigated agriculture (see Whitewater map). Currently, greater demand for residential housing is increasing development pressure in the area. Previously undeveloped areas are becoming residential plots. Increasing residential land use in the area has fostered concerns about potentially negative changes in water quality, specifically concerning the potential for increased selenium loading to the nearby Gunnison River.
Development in the area is expected to use independent septic drainage systems (ISDS). In addition, areas not historically irrigated will come under residential and ranchette style irrigation practices. Portions of the Kannah Creek, Whitewater Creek, and the entire Callow Creek basins are underlain by Mancos Shale, which is known to contain high concentrations of selenium. Increased water use in the area, ISDS installation, and suburban irrigation could be expected to increase the loading of selenium into the nearby Gunnsion River.
This project is collecting water quality and streamflow samples from the area with the goal of characterizing background conditions prior to the planned residential development. Evaluation of changes in selenium loading will provide additional insight into how land use practices and watershed conditions affect selenium loading to the local waterways. Evaluation of potential changes in water quality in this area will also guide the implementation of Best Management Practices (BMPs) that are suited to the local environmental conditions.