brief) water quality data set for Benton Lake. Since 1990, 

 specific conductance in pond #1 has varied across more than an 

 order of magnitude, with a maximiam reported concentration of 10920 

 microsiemens/cm. Three reported selenium concentrations ranged from 

 .001 to .011 mg/1. Spatial variability within the Benton Lake 

 complex can also be substantial. Synoptic sampling in August of 

 1986 showed pool #5 (the southeastern quadrant of the lake) to have 

 specific conductance approximately four times higher than pool #1; 

 reported boron concentrations were higher in pool #5 by a factor 

 of about 3, and arsenic was reported from pool #5 at 63 times the 

 concentration reported for pool #1. 



Sediments. The WET05 site exhibited the highest sampled 

 concentration of nickel and the highest zinc and second highest 

 selenium concentrations for a site in it's classification. WET05 

 was one of only five sites with a reported (barely) detectable 

 concentration of extractable cobalt. Sediment trace element 

 concentrations appear to show less spatial variability within the 

 Benton Lake complex than do water column concentrations. The 

 reported nickel concentration exceeds mean values for soils and 

 other surficial materials of the western U.S. by a factor of 4. 

 Selenium, zinc and cobalt exceed the regional soil means by factors 

 of 1.5 to 2. 



