DenseSludge™ Technology Reduces Sludge and Costs

The Client's Needs

CONSOL contracted Veolia Water Technologies to design a new Acid Mine Drainage (AMD) treatment plant at the North Branch site of its Island Creek Coal Company (Potomac Coal) operations. The treatment facility was designed to handle over 10,000 gpm of AMD from deep mine operations combined with other sources. The facility design incorporated Veolia's DenseSludge™ process to produce dewatered sludge that could be reinjected into the mine, with the treated water quality suitable for discharge to a tributary of the North Branch of the Potomac River.

Our Solution

CONSOL had previously contracted Veolia to design a retrofit AMD treatment facility using DenseSludge™ technology on a former coal refuse disposal site. This 2,000-gpm installation served as a pilot plant to demonstrate the benefits of the process and ultimately provided design criteria for the new facility.

Based on the performance of the 2,000-gpm treatment system, Veolia was awarded a contract for design of new facilities at the North Branch site, which allowed for closure of two smaller, outdated AMD treatment plants. The new facility treats over 10,000 gpm from two deep well pumps, surface runoff, coal refuse leachate, or a combination of these sources, achieving consistent compliance with the discharge limitations.

Design services included preparation of process flow diagrams, P&IDs, layout, expected facility loading requirements, development of bid packages (civil, mechanical, and electrical) and specifications with detail sufficient for CONSOL to obtain firm bid prices, which Veolia then reviewed.

Construction-phase services included equipment procurement for the major components of the new AMD treatment plant, including lime silo system, thickener/clarifier, aerators, and pumps, as well as oversight and management. Veolia prepared overall system operations and maintenance manuals containing process descriptions, start-up and shutdown procedures, emergency procedures, specialized troubleshooting techniques, wastewater testing and calculation instructions, and step-by-step preventive maintenance procedures.