Skip to main content
U.S. flag

An official website of the United States government

Coupling of hydrologic transport and chemical reactions in a stream affected by acid mine drainage

January 1, 1994

Experiments in St. Kevin Gulch, an acid mine drainage stream, examined the coupling of hydrologic transport to chemical reactions affecting metal concentrations. Injection of LiCl as a conservative tracer was used to determine discharge and residence time along a 1497-m reach. Transport of metals downstream from inflows of acidic, metal-rich water was evaluated based on synoptic samples of metal concentrations and the hydrologic characteristics of the stream. Transport of SO4 and Mn was generally conservative, but in the subreaches most affected by acidic inflows, transport was reactive. Both 0.1-um filtered and particulate Fe were reactive over most of the stream reach. Filtered Al partitioned to the particulate phase in response to high instream concentrations. Simulations that accounted for the removal of SO4, Mn, Fe, and Al with first-order reactions reproduced the steady-state profiles. The calculated rate constants for net removal used in the simulations embody several processes that occur on a stream-reach scale. The comparison between rates of hydrologie transport and chemical reactions indicates that reactions are only important over short distances in the stream near the acidic inflows, where reactions occur on a comparable time scale with hydrologic transport and thus affect metal concentrations.

Publication Year 1994
Title Coupling of hydrologic transport and chemical reactions in a stream affected by acid mine drainage
DOI 10.1021/es00061a014
Authors B. A. Kimball, R. E. Broshears, K.E. Bencala, Diane M. McKnight
Publication Type Article
Publication Subtype Journal Article
Series Title Environmental Science & Technology
Index ID 70017486
Record Source USGS Publications Warehouse
USGS Organization Toxic Substances Hydrology Program