By Kelly J. Kaczala
Press News Editor
OREGON - A professor from Ohio State University, hired by the city last June to evaluate Envirosafe's design plans to expand Cell M, found problems with the safety of the hazardous waste landfill's side slopes.
Dr. Charles Moore last fall issued a report that was critical of the slope's stability, The Press has learned.
Moore based his findings on the south slope stability analyses performed by The Mannik & Smith Group, an engineering firm hired by Envirosafe, which was included in the permit modification request submitted to the Ohio Environmental Protection Agency in December, 2003. Envirosafe, on Otter Creek Road, is seeking the modification so it can vertically expand Cell M, the only active landfill at the facility, from a height of 45 feet to 125 feet.
"There are several issues under Ohio EPA's guidance document that lead to the conclusion that the proposed landfill expansion will result in slopes that are not adequately designed with respect to their stability," says Moore in the report. "While the following issues are focused on the south slope, similar issues likely apply to slopes on the other sides of the landfill."
The safety factors for slope stability calculated by Mannik & Smith meet the Ohio EPA's standard when the elevation of waste in the landfill is 625 feet, says Moore. "However, the factor of safety requirements are not met for higher final elevations."
Moore was also critical of the leachate collection pipes at Cell M. In 2000, the pipes, which carry liquid from the landfill for treatment, had been crushed. As a result, Envirosafe installed steel inserts to strengthen the pipes. Moore's report says Mannik & Smith and their consultant, Dr. Timothy McGrath, used incorrect assumptions about leachate collection pipe placement that led to underestimating the loading on the pipes.
Their analyses, said Moore, "are applicable to negative projection pipes (pipes properly embedded in excavated trenches), whereas in actuality the leachate collection pipes have positive projections, (placed above the natural ground surface)."
Moore even quotes Dr. Robert Koerner, from a book he co-authored in 2002, "Geotechnical Aspects of Landfill Design and Construction," who cautions against the use of positive projection pipes:
"...every effort should be made to install in a negative projection mode."
The book further states that "...negative projection allows for soil arching which limits the load on the pipe. Conversely, positive projection can actually add load to the pipe."
Koerner, an adjunct professor at Drexel University and director of the Geosynthetic Institute, an organization supported by regulators, owners, consultants, testing laboratories, and manufacturers, is a long-time supporter of Envirosafe. He told The Press as recently as December that he supported the expansion of Cell M.
Moore's report further noted the failure to provide adequate protective gravel cover over the pipes "likely resulted in crushed pipes by heavy equipment used to compact the gravel."
Moore is one of two consultants hired by the city last year who raise concerns about the safety of the cell's side slopes and leachate collection pipes.
The Press reported two weeks ago that ARCADIS, an engineering firm hired by the city last November to review plans to expand Cell M, informed city officials in conference calls on Dec. 2 and Dec. 8 that Mannik & Smith's proposed design does not meet the prescribed factors of safety for slope stability that is established by the Ohio EPA.
ARCADIS also found that the leachate collection pipe, "which either has already failed or will soon fail, lacks adequate bedding."
"We are in agreement with the work performed by Dr. Moore regarding this subject," says ARCADIS.
The reports are significant because a decision by the Ohio EPA on whether to grant Envirosafe the permit modification is imminent. They are sure to raise the ire of environmental activists. Built in 1991, the cell is only two miles south of Lake Erie, and near Toledo's two raw water lines.
Despite the findings of both reports, Mayor Marge Brown's opposition to the proposed expansion has been waning in the last few weeks.
Brown has been meeting with Envirosafe President Doug Roberts to discuss increasing the .90 per ton tipping fee the city receives annually from Envirosafe based on waste dumped in Cell M, as well as other possible gains in exchange for limited support for the expansion.
Brown said the city hired ARCADIS for $17,000 on Nov. 18, soon after Moore's report was completed, because she had doubts about Moore's objectivity.
Moore, hired on June 14 for $15,000 to review Cell M's designs, was recommended by Tom Hays, the assistant city law director who represents Oregon on environmental issues, she said.
"I wanted someone who was objective, with no connection to the city or Envirosafe. And that's what I got with ARCADIS," said Brown.
Though Moore and ARCADIS both said there were deficiencies in the side slope stability of Cell M and its leachate collection pipes, Moore noted additional problems in Mannik & Smith's designs to expand the landfill, including:
Mannik & Smith conducted inadequate testing to characterize the actual waste stream in Cell M. The strength used for the waste in the slope stability analyses was based on five samples of electric arc furnace dust (K061), a byproduct of steel minimills, in the landfill. Assumptions are made that the waste is homogeneous and composed entirely of the dust, which is erroneous, says Moore.
Using Envirosafe's own reports to the Ohio EPA, Moore notes that waste receipt records from the summer of 1993 to 2000 shows that waste "of a large variety of types was received from multiple sources."
"From 1993 to 2000, some 705,219 tons of waste were received that was not K061. This represents 48 percent of the total hazardous waste received...from a large number of sources in some 30 states."
Besides K061, the landfill also contains baghouse dusts, contaminated soils, wastewater treatment sludge and filter cakes, contaminated concrete, storage tank sludge, blasting sand, plating sludge, grit sludge, treated industrial waste, treated debris, excavated soils, glass, contaminated wood plank, chromatic rags, and other wastes, said Moore.
"Many materials were merely classified as `confidential,'" he said.
"The assumption that the landfill waste is homogeneous and that its strength can be adequately represented by five K061 samples is untenable."
Volume I of Envirosafe's permit modification identifies tests that were supposed to be conducted to help characterize the strength of waste materials, said Moore.
"Personal communication with on-site personnel indicates that these required strength characterization tests were not performed."
As a result, said Moore, the safety factor for slope stability established by the Ohio EPA should be higher to account for the variability of the waste strength.
Moore and Mannik & Smith could not be reached for comment.
Jeffrey J. Swartz, project manager with ARCADIS, would not comment, saying the company's services to the city were "performed under attorney-client privilege."
"Unless the mayor allows it, I can't comment," said Swartz.
Dina Pierce, northwest district media coordinator for the Ohio EPA, said side slope stability "is a major component of our review."
Although Mannik & Smith's factor of safety of the side slopes did not meet the standard set by the Ohio EPA's geotechnical guidance document, as noted in Moore's and ARCADIS's reports, Pierce said it still fell within the "stable" range.
The value of side slope stability set by the Ohio EPA is "a conservative number and is generally what we would like to see," she said. "However, the evaluation is more involved than simply asking whether the factor of safety is above or below a certain value. When we move forward with a draft action, we will specifically detail the findings of our evaluation and how we got to those findings."
Ohio EPA is currently reviewing copies of the Moore and ARCADIS reports, she said.
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