Professor's diligence

credited with stopping

risky local landfill

"The best analogy I can come up with is for someone to put a septic tank and a well in the same place," said Zbigniew Kabala. "You don't do things like that."

A Duke associate professor of civil and environmental engineering, the Polish-born Kabala was describing why he volunteered his time and expertise to help a Durham County citizens group refute Orange County's plans to locate a solid waste landfill on Guess Road adjacent to the Orange-Durham boundary line.

The effort won him an official Oct. 11 resolution from the Durham County Board of Commissioners, which said he provided "an impressive presentation with detailed footnotes" that "completely discredited" a previous consulting engineer's report when he appeared at a Sept. 21 public hearing.

"His key arguments against the site included the fact that the site is only five miles from the source of drinking water for the city of Durham, and that it is bad hydrologic practice to place any landfill next to a river," the resolution added.

"Because of his compelling data, Orange County voted to drop consideration of the Guess Road site for the landfill," the commissioners wrote.

In an interview, Kabala described how he got involved after receiving a telephone request from a grassroots organization called People Opposed to Polluting the Little River to review the favorable report on the proposed construction and demolition landfill prepared by Orange County's own consultant, Joyce Engineering Inc.

"Since I live in Chapel Hill, I could serve as an arbiter who has no stakes involved in the issue," he said in an interview. "It took me three full days of analysis. I didn't realize it would take this long, but the more I got involved the more I realized how outrageous it would be to have this landfill there."

Kabala's investigation found that rainfall from any large hurricane would be sufficient to cause the Little River to overflow into parts of the landfill. The landfill would also accept pressure-treated lumber, which is made rot resistant with the aid of toxic arsenic compounds.

He concluded these two facts alone could lead to a pollution potential if river flood waters reached the treated lumber. That's because of the Ph.D. dissertation of Dianne Ahmann, now an adjunct professor at Duke's Nicholas School of the Environment, who found that wet conditions can promote the proliferation of bacteria that may release chemically bound arsenic.

Although emphasizing that Ahmann's work focused on river sediments, Kabala said similar conditions could arise in a landfill and arsenic could ultimately be released into underground water via fluid leakage known as a leachate.

"My point was that if there was a small likelihood that it would, they would definitely need a liner to keep the leachate from ever reaching groundwater," Kabala added. However, neither Orange County nor its consultants had any plan for such a clay liner, because the landfill was supposed to be a "dry" site, he said.

The landfill would also have accepted empty cans of solvent, which led Kabala to retort: "who's going to check every can? There will be some solvent left in them, and the stuff will drip," he said. And after 20 or 30 years of accumulation and migration, that could also lead to pollution of either the Little River or nearby underground water supplies, he predicted.

Another of his key objections was the lack of adequate testing.

Joyce Engineering's report itself agreed that no landfill location could be approved until officials could demonstrate that underground water rates of flow and pathways to the site "are understood, predictable and characterized," the Duke associate professor said. And, in an attempt to meet those mandates, the Orange County consultants checked how quickly disturbed underground water levels would return to equilibrium in eight different test wells.

But Kabala argued that these so-called "slug tests," which help predict the flow of groundwater, are useful only within yards of each well. That's especially true in the fractured rock underlying the proposed landfill, he said. As a result, he calculated that those eight slug tests could account for less than one-half percent of the 178 acres underlying the site.

Back in his native Poland, Kabala initially wanted to study physics but got interested in hydrology at Poznan Polytechnic, where he received a master's degree in civil engineering in 1980. Realizing that hydrology was a field that begged for more specialized mathematical training, he then got a separate master's in math from A. Mickiewicz University in Poznan before going to Princeton for his doctorate in water resources research.

His own research seeks to develop mathematical models and techniques that can better predict locations of and water movements within unseen underground reservoirs, called aquifers.

Another big goal is forecasting where this ground water will conduct pollutants that find their way into it.

In a separate proposed collaboration with Dharni Vasudevan, a Nicholas School assistant professor of environmental chemistry, he hopes to re-examine a cluster of decade-old childhood leukemia cases in Woburn, Mass., that were blamed on underground water pollution and prompted the motion picture "Civil Action."