On August 5, 2015, about three million gallons of water and sediment were released from the Gold King Mine near Silverton, Colorado, into Cement Creek, a tributary of the Animas River. The New Mexico Environment Department, among other State, Tribal, and local entities in CO, NM, and UT, is concerned that metals associated with the water and sediment released from the Gold King Mine could have long-term detrimental effects on surface-water quality of the Animas and San Juan Rivers, with potential risks to human health and the environment. The USGS, in cooperation with the New Mexico Environment Department, proposes to collect, analyze, and report surface-water quality data to characterize post-release conditions. The objectives of the study are to provide data that will improve the understanding of post-GKM-release surface-water quality for the Animas and San Juan Rivers under a variety of hydrologic conditions, including during high-flow events, and to provide real-time data on flow and field parameters that affected stakeholders can use to take whatever actions they feel might be necessary to protect public health. To accomplish these objectives, for a period of one year at four sites on the Animas and San Juan Rivers, the USGS will conduct continuous monitoring of water-quality parameters and will collect integrated water-quality samples during snowmelt runoff for analysis of major ions and dissolved and total metals. One site also will be instrumented with an automatic sampler to collect water-quality samples during snowmelt and storm events for analysis of major ions and total metals. The resulting data will be available through the National Water Information Systems database and its associated Web applications.
