Synoptic Studies

Many of the techniques employed by the Upper Arkansas Research Team at St. Kevin Gulch are now being used at other sites affected by acid mine drainage. The streams under study are typically headwater systems that gain significant amounts of water as they flow down valley. The sources of additional water range from well-defined tributary inflows that appear on topographic maps, to diffuse groundwater inflows that are not visible to the naked eye. The water quality associated with these sources of water also varies dramatically, ranging from dilute mountain springs to metal-rich waters emanating from mineralized areas. The challenge facing those interested in stream water quality is thus one of source determination: In a given watershed, what sources of water are most detrimental to the system under study? This question is of paramount importance to land managers who have limited resources with which to implement remedial actions.

The problem of source determination may be addressed by employing two well-established techniques: the tracer-dilution method and synoptic sampling. The tracer-dilution method provides estimates of stream discharge that are in turn used to quantify the amount of water entering the stream via tributary and groundwater inflow. Synoptic sampling of instream and inflow chemistry provides a spatially-detailed 'snapshot' of stream water quality. When used in unison, these techniques provide a description of the system that includes both discharge and concentration. Discharge and concentration data may be used to determine the mass loading associated with various sources of water. Sources representing the greatest contributions in terms of mass loading may then be the target of remedial actions.

Details on several synoptic studies are presented below.

Colorado

• Animas River
  • Eureka to Howardsville (1998)
  • A72 to Elk Park (1998)
• Cement Creek
  • Cement Creek (1996)
  • Ross Basin (1999)
  • Mayday Mine Dump(2000)
• Chalk Creek (1995)
• French Gulch (1996)
• Lake Fork of the Arkansas (2001)
• Mineral Creek (1999)
• Wightman Fork (Summitville CO) (1997)
• Willow Creek (Creede CO) (2000)

Montana

• Bullion Mine (1998)
• Lower Tenmile Creek (1998)
• Uncle Sam (1998)
• Soda Butte Creek (1999)

Utah

• Little Cottonwood
  • 1998
  • 1999

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