Nov 16

Luncheon Event November 29th, 2016

AWRA Colorado Section Presents

Lunch Talks

Tuesday, November 29th, 2016

The August 2015 Gold King Mine Release in the Context of Previous Geologic and Water-Quality Studies

Dr. Katie Walton-Day – USGS Colorado Water Science Center

In the late 1990s through early 2000s the U.S. Geological Survey (USGS) completed a watershed study in the upper Animas River watershed that provides geologic, geochemical, geophysical and biological background to interpret (1) the effects of the 2015 accidental release of 3 million gallons of metal-rich sediment and water from the Gold King Mine located on the north fork of Cement Creek, and (2) the effects of the last 15 years of remediation. The watershed comprises the headwaters of the upper Animas River, Cement Creek, and Mineral Creek, which join near the town of Silverton, Colorado. Historical mining occurred from the 1870s through the early 1990s, and left a legacy of abandoned mines and mine waste that degrade water quality. However, this mining occurred in a watershed where extensive hydrothermal alteration of the original geologic units helped create the economic mineral deposits, but also created non-highly mineralized, pyrite-rich rock that produces acid-rock drainage when weathered. Water quality in Cement Creek and lower Mineral Creek were likely degraded from acid-rock drainage prior to mining. USGS studies helped identify remediation targets, but occurred when placement of bulkheads to remediate mine drainage in the American Tunnel was ongoing. A series of bulkheads installed beginning in 1996, altered groundwater flow patterns in the area, and groundwater discharge rerouted to up-gradient abandoned mine tunnels. This change in the hydrologic regime underscores the need for re-evaluation of major sources of water-quality degradation in the upper parts of the watershed and re-evaluation and prioritization of remediation targets.


Dr. Katie Walton-Day – USGS Colorado Water Science Center

Dr. Katie Walton-Day is a Research Hydrologist and Water Quality Specialist for the USGS Colorado Water Science Center, Denver, Colorado.  Her primary research area is hydrologic and geochemical processes affecting metal mobility in wetlands, streams, soils, and groundwater affected by acid-mine drainage and mining processes.  Her research involves applying reactive transport and geochemical models, stable isotope analysis, and various geochemical analytical techniques to understand metal mobility in the environment. She received a B.A. in Geology from Smith College, and M.S. and Ph.D. degrees from the Colorado School of Mines in Geology with a minor in Geochemistry. She has worked with the U.S. Geological Survey since 1984.

Brown Bag Lunch and Networking at 12:00,

 Program at 12:15

Location: Leonard Rice Engineers
1221 Auraria Parkway

There is limited LRE visitor parking along with meters and pay lots nearby.
(Pay lots are cash only)

We will not be ordering lunch for this event. Please feel free to “brown-bag” it.

Cannot make the meeting in person? Check out the lunch talk through Go To Meeting at

You can also dial in using your phone.
United States: +1 (312) 757-3121
Access Code: 598-229-533

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