organic carbon concentrations all rank toward the mid-range of 

 values shown by sites classified with Lake Bowdoin. The arsenic 

 concentration ranked toward the lower end of the range shown by 

 Great Plains sites; boron, copper and iron concentrations ranked 

 mid-range within the site classification, and other trace element 

 concentrations were below reporting limits. 



Chemical history. Since 1978, the U.S. Fish and Wildlife Service 

 has conducted periodic monitoring of limited water quality 

 parameters at a site very near WET36. These data show a wide range 

 in specific conductance and pH. Reported values of specific 

 conductance range over two orders of magnitude (610 to 60,000 

 microsiemens/cm) and reported pH values range from an apparently 

 anomalous low of 7.5 to a high of 10.6. The specific conductance 

 measured for this sample (6070 microsiemens/cm) was below the 

 simple average for the USFWS data for this site (7582 

 microsiemens/cm for 131 measurements). 



Dissolved oxygen measurements also show a rather wide range, 

 including summertime lows in the 4 to 5 mg/1 range. No wintertime 

 data have been collected as part of this monitoring program. 



While there is some question about the extreme pH values reported, 

 generally these data show a very wide seasonal and interannual 

 variability at this site, driven by periodic importation of dilute 

 water from the Dodson Canal, followed by periods of evaporative 

 concentration in an essentially closed-basin setting. 



The spatial variability shown by the DHES sampling is substantial; 

 near-synoptic sampling of this site and WET38 near the lake outlet 

 showed 30% increase in total dissolved solids from inlet to outlet 

 areas. The mean specific conductance values for U.S. Fish and 

 Wildlife Service measurements from correlative sites show a 43% 

 higher mean for the outlet end of the lake. Generally, the 

 salinity gradient is likely to be steeper during more strongly 

 evaporative conditions. 



Sediments. The wide range of reported concentration of solutes in 

 the water column implies that periodic dissolution and re- 

 precipitation of authigenic mineral phases may occur at this site, 

 perhaps with complex effects on aqueous concentrations of nutrients 

 and trace elements. The sample collected from this site showed 

 arsenic, boron and iron concentrations near the low end of the 

 ranges shown for Plains sites. Other trace element concentrations 

 were below detection limits. Arsenic and boron concentrations were 

 below the reported mean soil concentrations for the Western United 

 States. 



