Environmental Effects of Western Coal Surface Mining. Part III:The Water Quality of Trout Creek,Colorado.

摘要

Water quality parameters have been measured at several on-stream and off-stream sites along Trout Creek,which is recipient of water from coal strip-mining operations. Levels of the gross parameters (e.g.,specific conductivity),the common ions (e.g.,calcium and sulfate),and some trace components (e.g.,selenium) are highest in mine spoil drainages. The impact of the mine spoil drainage on the stream is reflected in the larger quantities of dissolved solids and common ions found at on-stream sites adjacent to and below the mine. For trace elements,the mine operation has no detectable impact on Trout Creek in terms of increasing concentrations of Al,As,Cd,Cr,Cu,Fe,Pb,or Zn. Increases in stream concentrations of Mn and Se due to mine inflow can be inferred from the data. Higher concentrations of As,Fe,Mn,Se,and Zn are found in waters draining mine spoils. In the mine spoils,variations in the concentrations of these elements occur with spoil age;more Mn and Zn occur in older spoils,while higher levels of As,Fe,and Se are found in newer spoils. Chemical equilibrium calculations indicate that alkaline precipitation processes can maintain the low concentrations of Al,Cd,Cu,Fe,Pb,and Zn. The general alkaline characteristics of western streams and aquifers suggests that such precipitation equilibria will limit the soluble heavy metal concentrations.