Sediment and water chemistry of the San Juan River and Escalante River deltas of Lake Powell, Utah, 2010-2011

Open-File Report 2014-1096
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Abstract

Recent studies have documented the presence of trace elements, organic compounds including polycyclic aromatic hydrocarbons, and radionuclides in sediment from the Colorado River delta and from sediment in some side canyons in Lake Powell, Utah and Arizona. The fate of many of these contaminants is of significant concern to the resource managers of the National Park Service Glen Canyon National Recreation Area because of potential health impacts to humans and aquatic and terrestrial species. In 2010, the U.S. Geological Survey began a sediment-core sampling and analysis program in the San Juan River and Escalante River deltas in Lake Powell, Utah, to help the National Park Service further document the presence or absence of contaminants in deltaic sediment.


Three sediment cores were collected from the San Juan River delta in August 2010 and three sediment cores and an additional replicate core were collected from the Escalante River delta in September 2011. Sediment from the cores was subsampled and composited for analysis of major and trace elements. Fifty-five major and trace elements were analyzed in 116 subsamples and 7 composited samples for the San Juan River delta cores, and in 75 subsamples and 9 composited samples for the Escalante River delta cores. Six composited sediment samples from the San Juan River delta cores and eight from the Escalante River delta cores also were analyzed for 55 low-level organochlorine pesticides and polychlorinated biphenyls, 61 polycyclic aromatic hydrocarbon compounds, gross alpha and gross beta radionuclides, and sediment-particle size.


Additionally, water samples were collected from the sediment-water interface overlying each of the three cores collected from the San Juan River and Escalante River deltas. Each water sample was analyzed for 57 major and trace elements.


Most of the major and trace elements analyzed were detected at concentrations greater than reporting levels for the sediment-core subsamples and composited samples. Low-level organochlorine pesticides and polychlorinated biphenyls were not detected in any of the samples. Only one polycyclic aromatic hydrocarbon compound was detected at a concentration greater than the reporting level for one San Juan composited sample. Gross alpha and gross beta radionuclides were detected at concentrations greater than reporting levels for all samples. Most of the major and trace elements analyzed were detected at concentrations greater than reporting levels for water samples.

Study Area

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Sediment and water chemistry of the San Juan River and Escalante River deltas of Lake Powell, Utah, 2010-2011
Series title Open-File Report
Series number 2014-1096
DOI 10.3133/ofr20141096
Year Published 2014
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Arizona Water Science Center
Description v, 7 p.; 2 Appendices
Time Range Start 2010-01-01
Time Range End 2011-12-31
Country United States
State Utah
Other Geospatial Lake Powell
Online Only (Y/N) Y