State officials finally have a solution to the acidic runoff created by the Interstate 99 construction project -- but will it work?

Discovered more than a year ago, acid rock drainage created by exposed iron pyrite deposits at the I-99 construction site near State College has slowed the construction and raised environmental concerns for the Spring Creek watershed, an area that includes Penn State, said Walt Ebaugh, a hydrogeologist and member of the ClearWater Conservancy.

The ClearWater Conservancy is an organization that promotes conservation and environmental awareness in central Pennsylvania.

Ebaugh spoke on campus last week about the causes and severity of acid rock drainage as well as the efforts the Pennsylvania Department of Transportation (PennDOT) is using to combat the runoff.

Current monitoring has shown that the problem may be less severe than originally thought, and that the concentrations of sulfides created from the runoff in water samples are only slightly above prescribed limits, Ebaugh said.

"The larger effect may be in local wells, but personally, I believe it's probably not a groundwater problem," he said.

At these levels, the most noticeable effect of drinking-water contamination is a mild laxative property, he said.

He added that most wells in that area already have increased sulfide levels because of the properties of the rock into which the wells were drilled.

"Some wells are in the last place I would pick for a private well, but in this case you pay for a good view on the ridge by having hard water," he said.

Greg Schoenebeck (junior-nuclear engineering), who attended the discussion, said he was surprised to hear the impact of the acidic runoff may not be as severe as he thought it was.

When completed, I-99 will provide a faster, more efficient route from Centre County to Altoona and western Pennsylvania.

When construction began on Bald Eagle Ridge -- near a gap in the ridge known locally as Skytop, between State College and Port Matilda -- PennDOT unknowingly exposed large deposits of iron pyrite, which can easily create acidic runoff, Ebaugh said.

Unfortunately, he said, the construction site rests at the top of the headwaters for most of the surface water that drains into the State College area.

This runoff can lead to sulfide contamination in well water, groundwater and surface waters such as Buffalo Run, a small, high-quality trout stream near State College, he said.

To combat the runoff, PennDOT has begun implementing preliminary solutions that may slow or stop the acid rock drainage, Ebaugh said.

Impermeable plastic covers are being placed over exposed areas of iron pyrite, including rock faces and spoil piles, to minimize rock erosion and contaminated drainage, he said.

Also, surface pipes are being used to protect freshwater drainage streams coming off the mountain from becoming contaminated by the pyritic runoff, Ebaugh added.

Ebaugh said the long-range plan includes building an engineered landfill close to the construction site, which could be used for safe storage or neutralization of the acidic rock.

Fortunately, the majority of the rock that makes up the aquifers containing local groundwater is carbonate rock, which ultimately may work in an acid-base reaction to neutralize some of the acidic runoff, he said.

Ebaugh was brought to campus to give his opinion on the I-99 project by the Penn State Chapter of the American Water Resources Association (AWRA).

AWRA focuses on community outreach, networking and education of water resource and environmental issues, said Kristen Hychka (graduate-geography), a chapter member who helped plan the event.

Hychka said the I-99 project is one of the largest publicly funded projects in the country, and even though it has become a major environmental issue, AWRA was not sure how many students knew about the problems it has created in Centre County.

Anthony Buda (graduate-forestry), another member of AWRA, said awareness is the primary reason for having Ebaugh speak about the I-99 project.

"With better attendance at these meetings, it shows me that more people are finding this a problem that they should be concerned about," he said. "The more people know about the problem, the more they will be willing to do something about it."