Ecorisk Team met 28Apr2000 to discuss surface water sediment sampling needs for input to URS Corp surface water sampling round beginning 30 May 2000. The area were most mining activities took place contains highly sulfidic ore bodies. Several other previous investigations have focused on sampling surface water on several occasions under a variety of programs. The primary contaminants are zinc, copper, iron, and aluminum.
Acid drainage is also a problem.
Other metals are a concern to a lesser degree in specific areas. The SI and a loading evaluation for Strawberry Creek indicate that the worst affected areas are generally Strawberry Creek downstream of the water treatment plant discharge and upstream of Hoodoo Gulch. Loadings and concentrations in Hoodoo Gulch and Ruby Gulch may also be elevated. Concentrations and loadings generally decrease with distance downstream and in Bear Butte Creek. Concentrations of some of these dissolved metals exceed State of South Dakota Surface Water Quality Standards for Toxic Pollutants.