The lime -amended soil showed the smallest release 

 of dissolved arsenic, whereas the lime-and-phos- 

 phorus-amended soil showed the greatest release of 

 dissolved arsenic. 



The field site lysimeters were successfully sampled 

 until the end of August 1987, after which the soils became 

 too dry to obtain samples. Data from these samplings 

 indicate that field site results for arsenic during the first 

 year did not completely parallel laboratory results. The 

 lowest arsenic concentrations were found in lysimeter samples 

 from the control (untreated) plot rather than from the lime- 

 amended plot. For zinc and copper, the lowest dissolved 

 concentrations were observed in the lime-amended soils. 



An additional season's results are needed to confirm or 

 alter the field-site interpretations, which are based on a 

 limited sampling in 1987. 



Streambank Tailings and Revegetation Study 



As part of the Silver Bow Creek Superfund site Phase II 

 remedial investigation, the DHES has developed a program to 

 address the streambank mine wastes disseminated over much of 

 Silver Bow Creek and the upper Clark Fork. Typical remedial 

 measures for such wastes include removal or capping; however, 

 such measures may not be practical for sites such as Silver 

 Bow Creek that involve large areas of contamination and large 

 volumes of material. Therefore, the Streambank Tailings and 

 Revegetation Study (STARS) was initiated in fall 1987 to 

 investigate new and more innovative technologies to address 

 streambank mine wastes (CH2M Hill 1987c) . 



STARS is divided into two phases: a laboratory/green- 

 house phase to develop and test treatments at a bench scale 

 and a field scale phase to demonstrate selected remedial 

 alternatives. During Phase I, a variety of remedial measures 

 are being tested to modify the tailings characteristics 

 sufficiently to allow revegetation. Suitable soil amendments 

 to raise soil pH and reduce plant-available metal levels are 

 being developed, and plant species that can thrive in the 

 amended environment will be selected. Criteria for charac- 

 terizing streambank mine wastes based on their chemical and 

 physical properties are being developed. The Phase I final 

 report will include a preliminary design for innovative 

 remedial alternatives for each waste type identified. 



Laboratory and greenhouse studies were completed in the 

 fall of 1988. Phase II activities will include field 

 implementation of the remedial measures designed in Phase I. 



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