Oregon Water Science Center
LOCATION: Douglas County, Oregon
There is concern about the possible deleterious effects of acid mine drainage in the South Umpqua River Basin. Acid mine drainage results from sulfide oxidation in rock that is exposed to air and water, and is characterized by low pH, high acidity, and elevated concentrations of trace elements, sulfate, and total dissolved solids. The fluids resulting from acid mine drainage may be highly toxic, and, when mixed with ground water, surface water, and soil, may have harmful effects on humans, animals, and plants. Aquatic flora and fauna may be killed by even low concentrations of trace elements, such as copper, lead, and zinc. These organisms also have the ability to concentrate trace elements as they progress through the food chain to higher trophic levels.
The objective of this U.S. Geological Survey/Douglas County cooperative study is to provide management agencies in the South Umpqua River Basin with stream and sediment quality data to be used in determining whether the effects of ore mining operations and/or natural geologic ore deposits are observable in the downstream water and bed sediment chemistry, and are resulting in exceedances of water quality criteria.
Water and bed sediment samples will be collected at 10 sites, including 1 reference site that is assumed to be minimally affected by mining, during low flow conditions in August or September 1998. At each site, streamflow measurements and water-sample collection will be carried out according to standard USGS procedures.
A minimum of eight verticals will be sampled in a stream cross section, and the water will be composited into a churn splitter. The parts-per-billion protocol will be followed for the collection of samples for trace element analysis of filtered water. Bed sediment samples will be collected with a teflon scoop and composited from a minimum of 10 depositional areas. To ensure that only the most recently deposited material is being examined, only the surficial 2 to 3 centimeters of sediment will be collected. All samples will be immediately chilled until they can be processed in the field.
WRIR 99-4196. Inorganic Chemistry of Water and Bed Sediment in Selected Tributaries of the South Umpqua River, Oregon, 1998, By Stephen R. Hinkle. 1999