The $100 million ethanol distillery proposed for Conoy Township would be built atop an area laced with sinkholes, dissolving rock, vertical cracks and possibly a deep cave, experts have found.

But while opponents hope such findings will help sink the project, the chief engineer who performed the work, Lancaster Biofuels officials and the owners of the incinerator next door say it's neither surprising nor a big deal.

"I've built ethanol tanks in 10 states. I really don't see this as a poor site. I'd say it's an average site," said Joseph Waxse, the principal engineer who oversaw a detailed underground probe of the site in 2004.

Waxse and others say a base of dissolving limestone is not unusual in this part of the country, and there are engineering techniques to safely compensate for such undesirable conditions.

"The presence of sinkholes is just common for the area and can be dealt with. If you were to put a hotel there, you'd do the same thing," Waxse said in an interview Tuesday from his office in San Antonio, Texas.

Waxse's Terracon Consulting Engineers and Scientists of Omaha, Neb., was hired to do the subsurface examination by Penn-Mar Ethanol, the Lancaster-York-based group that wanted to build an ethanol plant on the 65-acre property owned by the Lancaster County Solid Waste Management Authority.

The subsurface studies were not part of the record for public hearings in the conditional-use process in Conoy, nor are they for the ones ongoing now for the Lancaster Biofuels proposal.

Facing stiff opposition, Penn-Mar dropped the project in early 2005 and sought another site in Franklin County. One of the reasons given for the abandonment of the project by a Conoy Township official at the time was the steep cost of building special foundations in the unstable rock on the site.

Seth Obetz, president of Lancaster Biofuels, said Thursday he and his own engineering team have known about the underground challenges on the site from the beginning. It's even been brought up to him by opponents of the plant, he said.

"Really, it was one of the first things we looked at. At this point, everything we've seen indicates that it's possible. It won't be cheap but the engineers indicate it's possible," Obetz said.

"You have to properly engineer the foundations. You have to allow for stormwater retention. You have to bring in experts and do stress tests on tanks," Obetz said.

"It's something we take very seriously. Obviously, we don't want to build something that will fail."

The geotechnical engineering report and a follow-up study on fractures found on the site were made after engineers drilled bores up to 45 feet deep and used aerial imaging and electronic soundings to learn what's going on under the surface.

What consultants found were 12 places that suggested sinkholes, caves and open voids in the soil on the verge of collapse.

If an ethanol plant is to be built, the consultants urged that "an increased level of construction observation and testing" be in place. They also predicted that "post-construction settlement is likely." Geo-consultants should be involved both during the design and construction phases, consultants said.

The geological complexity of the site rules out conventional foundations for buildings such as steel-driven piles. Instead, drilled, cased and grouted piles and drilled shafts are recommended.

The site, if built on, should have very controlled stormwater runoff, state Department of Environmental Protection Secretary Kathleen McGinty told Obetz several months ago. Water could percolate through the soil and further erode bedrock.

J. Daniel Wolf, president of Penn-Mar Ethanol, said there was "nothing prohibitive" about the subsurface findings in 2004. He said Penn-Mar left for Franklin County because a site there was more level and it appeared at the time that a plant could be erected there more quickly.

Wolf also said he didn't remember any sinkholes found on the Conoy Township site.

Extra-deep foundations were necessary when constructing the adjacent waste-to-energy incinerator. James Warner, the Waste Management Authority's executive director, said there have been no settling issues or sinkholes appearing on the property.

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