Sediments from the tailings contain high concentrations of iron, copper, lead, zinc, and arsenic. Over the years, the sediments from the tailings are being reworked and transported through the system, resulting in a reduction of toxicity and a gradual increase in the populations of macroinvertebrates and fish. Numerous investigations focusing on metals contamination have been conducted in the Soda Butte Creek basin recently. Conclusions reached by investigators on whether the tailings are currently impacting Soda Butte Creek differ greatly. The lack of consensus on whether the tailings are currently impacting the creek highlights the need for further investigation.
Floods are perhaps the most serious risk to aquatic life.
YNP has expressed interest in removing the McLaren tailings before another large flood occurs and the data from this intensive study would provide an important baseline before any excavation begins. One common complaint, voiced by NPS personnel and the researchers working in the area, is the lack of a retrospective analysis summarizing past studies of metals contamination in Soda Butte Creek and identifying data gaps. There are several areas for investigation as described previously. Because of resource limitations this project will not address loading from surface water runoff. An analysis of previous investigations of metals contamination in Soda Butte Creek is being conducted.