Revised and reposted March 1, 2013
The text of the report was modified.  The abbreviation for “microgram (u)” was incorrectly reported as “milligram (m)” on the following pages and sentences:
Page 1:  “One concentration of selenium in a sample from Bear Creek and concentrations of uranium in samples from Bear, Hardscrabble, and Ranger Creeks, and Brush Hollow equaled or exceeded U.S. Environmental Protection Agency (USEPA) drinking-water standards (50 and 30 ?g/L, respectively) for those elements.”
Page 2:  “Median dissolved selenium concentrations vary in the main-stem sites and ranged from 8.4 to 12.2 ug/L in Arkansas River near Avondale to Arkansas River at Las Animas, and selenium concentrations increase downstream at sites from Arkansas River near Nepesta to Arkansas River at La Junta.” “The median dissolved uranium concentration (39 ug/L) in Sixmile Creek exceeded the USEPA drinking-water standard.” “The tributaries, Sixmile Creek, IR-43, Huerfano River, and Chicosa Creek all drain the lower part of the Cretaceous-age Pierre Shale and upper part of the Niobrara Formation, which are suspected geologic sources of uranium.”
Pages 19 and 23: “Point-sample concentrations were larger than the associated EWI sample concentration in 13 of 18 sample pairs. However, the range in the absolute values of the differences was small, 0.1 to 2.7 ug/L.”
Pages 28 and 30: “Median dissolved selenium concentrations increased downstream from 0.17 micrograms per liter (ug/L) at Ark at Canon City to 0.43 ug/L at Ark nr Canon City to 0.69 ug/L at Ark at Portland and 1.10 ug/L at Ark nr Portland.” “Median dissolved uranium concentrations increased downstream from 2.57 ug/L Ark at Canon City to 3.20 ug/L at Ark nr Canon City to 4.38 ug/L at Ark at Portland and 4.76 ug/L at Ark nr Portland.” “Concentrations of dissolved selenium and dissolved uranium in water samples collected from the Arkansas River in the UARB did not exceed USEPA drinking water standards of 50 ug/L and 30 ug/L, respectively (U.S. Environmental Protection Agency, 2011).” “The concentrations of dissolved selenium in water samples collected from Arkansas River tributaries generally were less than the USEPA drinking-water standard of 50 ug/L.” “However, the concentration of dissolved selenium in one sample collected in Bear Cr (66 ug/L) exceeded the USEPA drinking-water standard of 50 ug/L.” “Concentrations of dissolved uranium in water samples from the Arkansas River tributary sites of Brush Hollow (34 ug/L), Hardscrabble Cr (30 ug/L), Bear Cr (36 ug/L and 37 ?g/L), and Ranger Cr (47 ug/L), equaled or exceeded USEPA drinking-water standard (30 ?g/L) (U.S. Environmental Protection Agency, 2011).”
Page 45:  “Median dissolved selenium concentrations at the main-stem sites ranged from 8.4 to 12.2 ug/L, increasing downstream from Ark nr Nepesta to Ark at La Junta (fig. 25A).” “Median dissolved selenium concentrations for tributaries generally were higher than those for main-stem sites; however, the median concentration at tributary site IR-43 (7.5 ug/L) was lower than other tributary or main-stem sites.” “The highest median selenium concentration (18.9 ug/L) was measured in the La Junta WWTP effluent (fig. 25A).” “No concentrations of dissolved selenium for any of the sampled sites exceeded the USEPA primary drinking-water standard of 50 ?g/L (U.S. Environmental Protection Agency, 2011).” 
Page 47:  “Concentrations of dissolved uranium in water samples from the LARB increase in the Arkansas River with distance downstream from Ark nr Avondale to Ark at Las Animas (fig. 3), with median concentrations ranging from 6.1 to 27.4 ?g/L (fig. 25B).” “The median uranium concentration (39 ug/L) in Sixmile Cr exceeded the USEPA drinking-water standard (30 ug/L) (U.S. Environmental Protection Agency, 2011).”
Page 56:  “One concentration of selenium in a sample from Bear Creek and concentrations of uranium in samples from Bear, Hardscrabble, and Ranger Creeks and Brush Hollow equaled or exceeded U.S. Environmental Protection Agency (USEPA) drinking-water standards (50 and 30 ug/L, respectively) for those elements.”
Page 57:  “Median dissolved selenium concentrations vary in the main-stem sites and ranged from 8.4 to 12.2 ug/L in Arkansas River near Avondale to Arkansas River at Las Animas, and selenium concentrations increase downstream at sites from Arkansas River near Nepesta to Arkansas River at La Junta.” “The median dissolved uranium concentration (39 ug/L) in Sixmile Creek exceeded the USEPA drinking-water standard.” 
Revised and reposted October 10, 2014
Page 36:  Changed the units of measure in both axis labels from "millimeters" to "per mil."
Page 52:  Changed the units of measure in both axis labels from "inches per millimeter" to "per mil."