THE EFFECTS OF LIME NEUTRALIZATION OF
ACID MINE DRAINAGE ON STREAM ECOLOGY
Edwin E. Herricks, Assistant Professor
Department of Civil Engineering
Unitersity of Illinois
Urbana, Illinois 61801
John Cairns, Jr., Professor
Department of Biology
Virginia Polytechnic Institute and State University
Blacksburg, Virginia 24061
INTRODUCTION
The mitigation costs associated with the control of surface and subsurface drainage from
mining operations has been one of the major concerns of environmental control activities in
the mining industry. Typical mine source waters are high in total dissolved solids, principally
metals and sulfate, low in pH (if so, usuaUy classed as acid mine drainage, AMD) and, depending on the source and condition of the land surface, high in total suspended solids.  Severe
mine drainage problems are most generaUy associated with Appalachian coal mining where
steep slopes are an abundance of pyritic minerals in the coal or overburden produce severe
sediment and AMD problems [ 1]. Mine drainage impacts, particularly AMD, are not limited
to Appalachia. Midwestern area mining operations disturb large surface areas leaving accumulations of low-quality mine drainage in pit lakes or low-lying areas.  Lead mining in Missouri and bauxite mining in Arkansas also produce severe localized AMD. Although the most
severe mine draining problems generally occur in high rainfall areas (moisture as well as oxygen are required for the weathering of pyrite to AMD components) many streams in the
Rocky Mountain West are subject to metal-mine draininge, often with low pH.
The solution to mine drainage problems involves both the stabUization of the surface environment to reduce erosion and isolate the acid producing materials and the treatment of
any AMD. Erosion and sediment control, particularly when integrated in preoperational
planning [2], have weU defined operational procedures [3].  Unfortunately, water treatment
is not as straightforward. Variability in drainage characteristics, major fluctuations in volumes, expensive treatment process and possibly environmentaUy damaging endproducts of
treatment all affect selection of water quality control techniques [4]. The optimum water
quality control technology should involve low capital cost, effective treatment and minimal
operating expenses. To achieve this goal, the Pennsylvania Department of Environmental
Resources developed an automatically operated hydrated lime neutralization system for small
streams affected by nonpoint source mine drainage [5]. This paper wUl review the effectiveness of the treatment plant and process on mine drainage in the Little Scrubgrass Creek,
Pennsylvania with special emphasis on the secondary impact of AMD neutralization on stream
biota.
LITTLE SCRUBGRASS CREEK
History
Mining operations began in the Little Scrubgrass basin in the early 1900's. Eleven deep
mines and numerous surface mines were operated in the watershed. Deep mines were abandoned by 1950; surface mining continued sporadically untU 1960 with a resurgence in 1970.
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