The western portion of Pond #1 has been treated and capped and the 

 process of establishing vegetation on the capped surface begun. 

 Future water levels in the eastern portion of Pond #1 (including 

 the WET76 site) may be manipulated to retain reducing conditions 

 in wetland sediments. 



Water chemistry- At the time of sampling, Pond #1 contained 

 "oligosaline" calcium-sulfate water of low alkalinity and 

 moderately basic pH. Equilibrium calculations indicate moderate 

 oversaturation with carbonate minerals. Nitrogen concentrations 

 (nitrate and ammonium) were below reporting limits. Phosphorous 

 (total and orthophosphate ) and total organic carbon concentrations 

 ranked mid-range among sites of the intermontane valleys. 



Water-column concentrations of boron, copper, iron, lead and zinc 

 ranked near the upper end of the ranges shown for intermontane 

 sites. The arsenic concentration ranked mid-range, and most other 

 trace elements occurred in concentrations below reporting limits. 



Chenical history. Although DHES documents (see bibliography) 

 identify this as a sampling site, no other water chemistry data 

 were recovered. See discussion above for general history of water 

 chemistry factors. 



Sediments. Sediments collected at WET76 show the highest 

 extractable concentrations in the sample set for many trace 

 elements, and in general may reflect the most heavily contaminated 

 conditions of the mining-impacted sites. Extractable 

 concentrations of arsenic, chromium, copper, manganese, selenium, 

 and mercury ranked at the top of the range shown by the data set; 

 boron, iron, lead, vanadium, and zinc concentrations rank near the 

 top also. These elements exceed geometric mean values for soils 

 of the western United States by factors ranging from 1.5 to more 

 than 100. 



