CONTROLLING ACIDIC-TOXIC METAL LEACHATES FROM SOUTHERN APPALACHIAN CONSTRUCTION SLOPES: MITIGATING STREAM DAMAGE

Highway construction activities in the southern Applachian Mountains have exposed geological formations that contain pyritic materials (Anakeesta formation), and drainage from slope and fill has caused considerable change in streams that receive these toxic leachates. These drainages, which mobilize high levels of free acidity (low pH) and various toxic metals (aluminum, copper, iron, maganese, and zinc), have destroyed aquatic ecological systems in reaches of mountain streams of the Great Smoky Mountains National Park and tributaries of Citico River and Tellico River drainages in the Cherokee National Forest. In the North River drainage of the Tellico River, mitigation procedures were initiated in 1977 by FHWA to seal exposed Anakeesta road fill of the Tellico-Robbinsville Highway with soil blankets and temporary sodium hydroxide (NaOH) neutralization. A study conducted to evaluate the effectiveness of the controlling technologies used in meeting water-quality objectives is described. Assays of fish population, in-stream fish bioassays, and water-quality assessments were carried out in the watershed during 1978-1979. Initial improvements in stream water quality and biological accommodations occurred in mitigated streams during NaOH treatments and soil blanket installations. However, survivability tests and fish surveys revealed that rainbow trout could not survive in acid streams 6 months after the soil blankets had been installed. Depressed pH and elevated metal concentrations contributed to fish mortalities in these streams. (Author)

Media Info

  • Media Type: Print
  • Features: References; Tables;
  • Pagination: pp 10-16
  • Monograph Title: WETLANDS, FLOODPLAINS, EROSION, AND STORM WATER PUMPING
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00389547
  • Record Type: Publication
  • ISBN: 0309036690
  • Files: TRIS, TRB
  • Created Date: Nov 30 1984 12:00AM