SUMMARY OF THE REMEDIATION TECHNOLOGIES DEVELOPMENT FORUM
IN-PLACE INACTIVATION AND NATURAL ECOLOGICAL RESTORATION
TECHNOLOGIES SOIL-METALS ACTION TEAM
CONFERENCE CALL

December 20, 2000

11:30 a.m.-12:30 p.m.

On Wednesday, December 20, 2000, the following members of the In-Place Inactivation and Natural Ecological Restoration Technologies (IINERT) Soil-Metals Action Team met in a conference call:

Bill Berti, DuPont Central Research and Development (Action Team Co-Chair)
Sally Brown, University of Washington
Rufus Chaney, U.S. Department of Agriculture (USDA)
Harry Compton, U.S. Environmental Protection Agency (EPA)
Mark Doolan, EPA
Jim Dwyer, U.S. Fish and Wildlife
Scott Fredericks, EPA
Frances Klahr, Missouri Department of Natural Resources
David Mosby, Missouri Department of Natural Resources
Gary Pierzynski, Kansas State University

Christine Hartnett of Eastern Research Group, Inc. (ERG), was also present.

THE JASPER COUNTY SITE

David Mosby provided information about a mining site located in Jasper County, Missouri. Tailings and chat, he said, are present and causing harm to the surrounding ecosystem. For example, he said, runoff from the mine waste is contaminating a nearby stream. Also, studies suggest that the chat poses significant ecological risks to terrestrial organisms. The most sensitive receptors, Mosby said, are vermivores, shrews, and woodcocks. Lead, zinc, and cadmium are the main risk drivers, Mosby said, noting that these metals are present in high concentrations in the site's soil and plant tissues. The concentrations documented in plant tissues might be skewed, however, because soil attached to the plants was not washed off prior to analysis. In addition, Mosby said, some of the estimated risks may be overinflated: several conservative assumptions were used to perform the ecological risk assessment. Mark Doolan said that the risk estimates could be refined in the future if more site-specific information becomes available.

Mosby said that a Feasibility Study (FS) is being conducted at the site; the study's goal is to identify remedial options for the nonresidential portion of the site. He said that the potentially responsible parties (PRPs) must identify options, but Doolan (i.e., EPA) will decide which approach to implement. Mosby said that the PRPs plan to propose the following alternatives:

• Capping. Mosby said that a soil cap is being considered as an option, noting that a local topsoil vendor sells soil at a low price. No decision has been made about how deep the topsoil cap would need to be. Conference call participants offered comments on the capping option. If the cap is less than 30 inches thick, Rufus Chaney said, the soil must be alkaline to prevent roots from penetrating into the chat area and taking up contaminants. (Chaney said that papers published in Europe back up this claim.)

• Bulldozing waste into pits. Mosby said that some consideration is also being given to bulldozing mine waste into subsidence pits. The Missouri Department of Natural Resources is not too happy with this option, because it could impact area ground water. Mosby acknowledged that the ground water is already contaminated, but said that the "subsidence pit" approach could cause further deterioration of ground-water quality. He said that the PRPs claim that this approach is beneficial in the long run because the pits will eventually be converted into a reducing environment--a condition that limits metal mobility. Mosby said that this transformation will take time, however, and until it occurs the wastes will be extremely mobile. It is unclear, he said, how long the "mobility" period will last.
  
  
• Deep tilling. Mosby said that some consideration is being given to plowing some of the smaller chat piles into the ground. Chaney commented on this proposed approach: he said potential toxicity and acidification problems could result.

Mosby said that biosolid treatments should also be listed as a viable alternative in the FS, noting that this technology treats contamination and promotes revegetation. He said that the Missouri Department of Natural Resources regards both functions to be important. The Department hopes to go beyond remediation and to promote habitat restoration. The ideal goal, Mosby said, is to maximize the area's future productivity rather than just performing damage control.

In an effort to convince the PRPs of the merits of biosolids, Mosby said, data documenting the technology's success at other sites was provided. The PRPs responded by saying they feared that biosolids would promote revegetation and attract animals to contaminated areas. According to Mosby, the PRPs felt that biosolid technologies are untested and that the data provided to them do not adequately address toxicity issues, prove that biosolids cause a treatment effect, or demonstrate that the technology reduces bioavailability. Conference call participants expressed puzzlement over this last statement. They said that the data do address toxicity and bioavailability issues. To prevent any misunderstandings and to facilitate clear communication, call participants agreed to present the following to Doolan by mid-February 2001:

• A short summary paper. Call participants agreed that a short position paper should be written on the use of biosolids at metal-contaminated sites and what has been learned about the technology's impact on ecosystem risk. The paper will provide short summaries of what has been learned in the laboratory and at different sites. For example, the paper will explain how TCLP, MEP, and SPLP laboratory tests all point to the same conclusion: biosolids cause metal immobilization. The paper will also highlight conclusions about biosolids' impact on toxicity for different receptors. References will be provided so that readers know where to find more detailed information. Sections will be included on toxicity studies performed on earthworms, voles, shrews, cows, and plants. Chaney described a cattle-feeding study to provide an example of the type of information that would be useful to include in the document: he said that biosolids were applied to a smelter slag site in Poland, forage was grown on top, and vegetation was fed to calves for 90 days without causing any deleterious effects. Mosby also advised providing information about what causes the treatment effect that is observed with biosolid technologies. He said that the PRPs suspect that the effect that researchers attribute to biosolids is a byproduct of changing pH conditions. Sally Brown said that the PRPs' suspicion is erroneous--data collected from the Leadville site will show this. Call participants agreed that several people should be asked to provide information for the paper: Brown, Chaney, Harry Compton, Gary Pierzynski, Jim Ryan, Mark Sprenger, Scott Fredericks, and Nick Basta. Brown noted that many of these people will be gathered together in Las Vegas in mid-January for a meeting. She agreed to contact these researchers to ask them to stay in Las Vegas for an extra day so that they can provide input on the document. Those who cannot attend, she said, will be consulted via teleconference.

• An oral presentation. Call participants agreed that an oral presentation on biosolid technologies should be presented to Doolan and other Region 7 regulators. They agreed that the presentation should take place in Kansas City in February 2001, and that it should be led by Sprenger.
  
  
• More realistic information about the costs of biosolids technologies. Brown said that the City of Springfield has generated cost estimates for biosolid technologies. Mosby thought that the PRPs had received information about the estimated costs. This concerned Brown; she said that the costs generated were unrealistic and overinflated, and could unnecessarily lead one to believe that biosolids are not as cost-effective as other remedial alternatives.

ACTION ITEMS

• Brown will contact researchers to determine whether they can meet in Las Vegas in mid-January to work on a document that summarizes research on biosolid technologies. This report will be completed by mid-February 2001.
  
  
• Call participants agreed that Sprenger should lead the presentation that will take place in Kansas City in February 2001. Compton agreed to communicate with Sprenger to find out when he is available to give the presentation. Compton and Sprenger will work with Doolan to identify an appropriate date for the presentation.
  
  
• Brown will obtain more realistic cost estimates for the biosolids work that is being performed in the city of Springfield. She will distribute this information to Action Team members.