i-99

Media, Legislative Tour Held for I-99 Acid Rock Drainage Bauxsol Demonstration Site

WILLIAMSPORT (Sept. 12) -- A tour of the I-99 acid rock drainage Bauxsol demonstration at the buttress/bifurcation site was given by PennDOT on Sept. 9 for regional media and local state legislators. DEP Community Relations Coordinator Dan Spadoni and Local Government Liaison Dan Vilello participated as well.

The $1 million demonstration project, which is being done under contract with PennDOT by Virotech USA Inc., began in mid-August and will conclude before the end of October.

On Friday, Virotech CEO Neil Brach explained to the tour group that the objectives of the project are to reduce the existing acidity via introduction of alkaline agents, and stop the future creation of acid through inhibition of pyretic reactions, which are the source of the problem.

Brach said there are three different procedures being used by Virotech to attack the acid problem. First, the company is introducing via infiltration of a prescribed Bauxsol slurry into the limestone blanket at the buttress/bifurcation site to create an alkaline barrier between the fill and native rock.

Virotec is also using a drip or spray irrigation treatment of a prescribed Bauxsol slurry onto the surface of acid-producing fill material to reduce the actual acidity and impede the formation of new acidity.

Finally, the company is using horizontal and vertical injections of the slurry into fill areas around and beneath the completed section of highway through the use of bore holes.

Bardach noted that the signs of successful treatment include an increase in acidity in lysimeters and monitoring wells as acidic pore water is displaced. This will be followed by an improvement in acidity and electrical conductivity in the monitoring wells as treatment progresses. Finally, there will be a reduction of acidity, sulfates and metal contamination in ground water.

The use of Bauxsol to help solve the I-99 acid rock drainage problem is only one of three possible solutions being examined by PennDOT. The others include removal of the acid-producing rock to an engineered disposal area, and to a flyash disposal facility in Indiana County.