Selenium geochemistry at Bosque del Apache Wildlife Refuge
— John L. Persico and Douglas G. Brookins

Selenium is recognized in many areas as a contaminant of surface water, ground waters and soils. In New Mexico the Bosque del Apache National Wildlife Refuge has been identified by the U.S. Department of the Interior as a potentially contaminated site. Accordingly, we have investigated the behavior, speciation and environmental impact of selenium at this site.

Selenium contents in sediments at Bosque del Apache range from 0.17 to 0.37 ppm, values well below what personnel of the U.S. Fish and Wildlife Service consider dangerous to wildlife and waterfowl. The selenium present does not correlate with ferric iron, pH, clay mineralogy or organic carbon content. More than 50% of the selenium is present in the sediments as Se(VI). Irrigation and impounded waters at the site contain less than 1.5 ug/L selenium, and the dissolved selenium appears to be due to t he original sediment. Again, the selenium content of the waters is well below the safety level of 10 ug/L advocated by the U.S. Environmental Protection Agency.

These studies show that selenium is not of major concern for water and sediment contamination at the Bosque del Apache National Wildlife Refuge at the present time. We recommend continued monitoring, however, using the results of this study as comparative background.