Idaho Cobalt Mining Project Biological Monitoring

EcoAnalysts was contracted by an undisclosed client to perform a biological survey to comply with the requirements of NPDES permit which requires that a biological survey be conducted. This biological survey was to include fish tissue metals, benthic macroinvertebrate, and stream and riparian habitat measurements. Three locations were sampled for this project. Two locations were on Big Deer Creek which represented the stream where the NPDES discharge would occur. These locations were sampled for fish tissue, macroinvertebrate communities, and stream habitat. One station was upstream of the discharge and the other was downstream. Fish tissues were also collected at a third location on Upper Blackbird Creek which represented background tissue concentrations.

EcoAnalysts performed the habitat survey and collected all of the samples in the field. IDEQ’s stream habitat index 2 (SHI2) was used to compare the results from the habitat survey. EcoAnalysts processed all of the benthic macroinvertebrate samples and calculated indices following IDEQ stream macroinvertebrate index 2 (SMI2), Hilsenhoff’s biotic index (HBI), and metals tolerance index (MTI). Fish tissue samples were couriered to an analytical laboratory and processed for metals (aluminum, arsenic, cadmium, cobalt, lead, manganese, mercury, nickel, selenium, thallium, and zinc). Results from the macroinvertebrate and fish tissue analyses were used to compare upstream and downstream locations. EcoAnalysts drafted a report that summarized the methods and results of the biological survey.