English

Abstract

Abandoned mine drainage is a major source of water pollution in Pennsylvania, West Virginia, and other historical mining districts. Technology which utilizes no harsh chemicals and no electricity, and requires minimal maintenance known as passive treatment is being developed to address this pollution problem in a relatively cost-effective manner. Specifically, acidic drainage with dissolved aluminum and/or high iron content is now being successfully abated utilizing a916 type of passive system which uses a component known as a Vertical Flow Pond (VFP). VFPs are also referred to as Reducing and Alkaline Producing Systems or RAPS. Numerous papers and technical investigations have provided documentation on the effectiveness of these systems in treating discharges of various qualities and flow rates. Very little information, however, is available regarding the piping systems used for the collection of the water after passing through the treatment media. These piping systems are often referred to as underdrains. Experience gained during installation and from on-going monitoring of successful VFPs at the Jennings Environmental Education Center and Ohiopyle State Park (PA Dept. of Conservation and Natural Resources) and within the Slippery Rock Creek Watershed has led to the development of an innovative double-tiered, multiple-quadrant, underdrain system. This type of underdrain has been recently installed at the De Sale Restoration Area - Phase II (De Sale II) site in Venango Township, Butler County, PA. This underdrain system is expected to aid in eliminating dead areas and in maintaining the hydraulic conductivity of the treatment media by improving flow distribution and by improving the ease and thoroughness of the flushing operation to remove accumulated metal solids.