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

March 27, 2000
4:00 p.m.–5:00 p.m.

On Monday, March 27, 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)
James Ryan, U.S. Environmental Protection Agency (EPA) (Action Team Co-Chair)
Sally Brown, University of Washington
Rufus Chaney, U.S. Department of Agriculture (USDA)
Andrew Green, International Lead Zinc Research Organization
David Mosby, Missouri Department of Natural Resources
Gary Pierzynski, Kansas State University
Mike Ruby, Exponent Environmental Group
Sebastien Sauve, NRS-Institut Armand-Frappier-Santé
Qi Xue, USDA

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

THE JOPLIN, MISSOURI, SITE

The Number of Plots at Joplin and a Summary of Recent Sampling Events

Fourteen treatments are being tested at the Joplin site: ten were established by USDA, and the University of Missouri-Columbia established the others. Each treatment has four replicates; thus, there are 56 plots at the Joplin site. Sally Brown said that samples were collected from all 14 treatments in 1997, 1998, and 1999. Call participants made note of two sampling events that were conducted in late 1999:

• October 1999. Brown and Bill Berti collected soil samples in October 1999, but were unable to obtain large sample quantities because the ground was hard and dry. Brown said that a soil probe was used to collect the samples, and that samples were collected to a depth of 10 centimeters. Each sample is a composite, she said: four to six cores were collected per plot.

• November 1999. David Mosby collected soil samples from three treatments (control, 0.5% phosphoric acid [P], and 1% P). A spade was used to collect the samples, he said, and sample depth ranged from 0 to 15 centimeters. The samples, which were composites, were collected in a five-star pattern. Mosby said that he collected about 40 to 50 kilos of soil, and delivered the samples to John Yang, who agreed to sieve the soil, store it, and distribute it to researchers.

Plant Extraction Studies

Berti asked Sebastien Sauve to talk about using a potassium nitrate solution to perform plant extraction studies. Sauve said that he has used this extraction solution (in combination with anode stripping voltametry) to measure metal concentrations. He said he was willing to perform analyses on the Joplin samples, and agreed to draft plans for this work. Call participants, who were very enthusiastic about this idea, discussed which metals should be analyzed. They agreed that lead must be analyzed, and that it might be useful to evaluate zinc and cadmium as well. (Brown said that available data indicate that treatments significantly impact lead, zinc, and cadmium concentrations.)

Berti said that he wants Sauve to perform analyses on the samples that were collected in October 1999. Berti said that he will review his sampling log to determine whether enough sample is available to conduct these analyses. (Sauve needs about 20–25 grams.) In addition, Berti said, if sufficient quantities of sample are available, DuPont will consider analyzing the samples using a calcium nitrate solution.

Animal-Dosing Studies

Conference call participants discussed two animal-dosing studies that are getting underway.

Swine Study

The University of Missouri-Columbia’s Stan Casteel has initiated a swine-dosing study. As part of this study, Mosby said, pigs are being fed two of the treatments (0.5% P and 1% P) that were collected during the November 1999 sampling event. The control sample will not be fed to the pigs; instead, Casteel will use results from last year’s "pre-control" as a baseline for bioavailability. James Ryan questioned this decision, noting that variation in lead bioavailability data has been detected in control samples over time. He reminded Mosby that other researchers have had difficulty interpreting data when they have not included a control in their study.

One conference call participant asked how much soil Yang sent to Casteel. Qi Xue, who talked to Yang before the conference call, said that Casteel received 1 kilo of soil. Conference call participants questioned why Casteel would need so much; Mosby agreed to talk to Yang about this.

Rat Study

Rufus Chaney said that USDA’s Judith Hallfrisch and Xue will start dosing rats in April 2000. They are discussing feeding the following treatments during this phase of the rat-dosing study:

• The three treatments (control, 0.5% P, and 1%P) collected in November 1999. Assuming that sufficient sample quantities are available, Chaney said, USDA will definitely feed these samples to the rats. (Chaney said that he received an e-mail from Yang; it implied that there might be a shortage of sample. Mosby was surprised by this, noting that he collected plenty of soil during the November 1999 sampling event. Mosby agreed to contact Yang to find out [1] what fraction of the sample was discarded after sieving, [2] how much had been sent to Casteel, and [3] how much remains in storage. Mosby will forward Yang’s responses to Ryan.)

• A fourth treatment. Chaney said that USDA may feed a fourth treatment to the rats, and apply it at three different rates. He said that he is not sure which treatment would serve as the "fourth treatment." Ryan advised dosing the hydroxy appetite treatment. Brown recommended dosing the 10% compost treatment, noting that laboratory studies indicate that this treatment is very effective. If USDA does decide to dose another treatment, a USDA representative will travel to Joplin in April 2000 to collect a sample.

Chaney said that USDA may be able to initiate another phase of rat-dosing studies in about 6 months. During this phase, samples from four different treatments would probably be fed to rats.

In Vitro Analyses

Mike Ruby said that he would like to perform in vitro tests on the soils that were collected in November 1999. He asked whether he could obtain 10 grams of the control, 0.5% P, and the 1% P samples. Mosby will contact Yang to determine how much sample is available; he will forward Yang’s response to Ruby.

Brown said that she plans to run in vitro analyses on samples that were collected from the 10% compost treatment. (In vitro analyses have already been performed on these samples, but using a low pH; Brown will use a higher pH when she performs the analyses.) Brown said that Ruby sent her the equipment that is needed to perform the in vitro tests.

Future Considerations: Collecting, Storing, and Distributing Joplin’s Soil Samples

Chaney reminded participants that there are 14 treatments at the Joplin site. In order to perform animal-dosing studies, he said, researchers will have to collect large quantities of soil during sampling events. He said that there may be enough soil available to perform animal-dosing studies for three of the treatments (control, 0.5% P, and 1%P—all collected in November 1999); Mosby will check to make sure that this is the case. Over the next year, Chaney said, USDA may dose five additional treatments. (One of the treatments would be dosed before the end of April; the others would be fed about 6 months later.) In addition, Chaney said, USDA (or other investigators) may decide to dose additional treatments. Thus, it is possible that large quantities of soil will need to be collected from the 11 remaining treatments over the next year. Ryan said that he and Chaney have been trying to decide the best way to conduct sampling efforts; two options have been identified. Ryan said that a series of sampling efforts could be conducted. If this approach is taken, samplers would visit the Joplin site on multiple occasions and collect samples only from the specific treatments that are needed for individual studies. Alternatively, he said, samples from all of the treatment plots could be collected during a single event and stored in a repository. That way, samples would be readily available to all legitimate researchers who want to analyze Joplin’s soils. Conference call participants expressed interest in collecting samples from all of the treatment plots at once, but they did bring up the following questions:

• Where would the samples be stored? One conference call participant asked whether storage space was available. Ryan said that he has space available, and agreed to serve as the repository for all Action Team samples. Mosby agreed to talk about this with Yang.

• Does bioaccessibility change over time in a sample that has been air-dried, sieved, and stored over several months? Ruby responded to this question: he said that variations in bioaccessibility are negligible over time, at least in untreated control samples. Berti said that he was not sure that this would be the case in samples that had been amended in the field. Gary Pierzynski said that he has some data, which will be released soon, that might help answer the question. (Pierzynski said that his laboratory incubated samples [untreated controls and treated samples] for a 1-year period and sampled these over time. Results appeared to be influenced to some extent when the samples were sequentially extracted, but the effects of time were negligible when the samples were exposed to in vitro tests.)

Call participants talked about the amount of soil that should be collected for each of Joplin’s treatments. Chaney recommended collecting about 5 kilos of sieved material for each treatment. If for some reason the Action Team finds that they do not have enough sample, Ryan said, then analyses should be prioritized. First, he said, soil should be distributed to researchers who are performing animal studies. Next, a portion of the soil should be placed in storage so that it is available for speciation work. If enough remains, he continued, it could be used for in vitro analyses.

Summarizing the discussion, Berti said that it appears that call participants are in favor of collecting large composites of soil from each of Joplin’s treatments during a single sampling event. Berti asked when this large sampling effort could be conducted. Chaney said that he might be able to do it in April 2000. If USDA decides to dose rats with a fourth treatment, he explained, a USDA representative will travel to the Joplin site to collect the sample before the end of April. If such a sampling event is scheduled, it might be possible to collect samples for all of the treatments at that time. Mosby offered to help USDA with the effort. Chaney said that he may ask Mosby to accompany the sampler, and to act as a field interpreter.

OTHER SITES

• A site with mine wastes. Mosby said that Mark Doolan received a grant from EPA to treat soils that are contaminated with mine waste. No final decisions have been made about which treatments to use, Mosby said, but it is likely that phosphoric acid, lime, and biosolids will be included in the treatment study. Activities are anticipated to start in spring 2000.

• A site near Springfield, Missouri. Brown said that she is working with Harry Compton and Scott Fredericks on a biosolids project. Materials have already been spread in some areas, she noted, and are stockpiled in others. Brown plans to visit the site in May or June 2000.MISCELLANEOUS

• Ruby said that an arsenic hyperaccumulator has been developed by Edenspace Systems Corporation and the University of Florida. A representative from the former contacted Ruby to ask whether in vitro tests can be used to measure arsenic bioavailability. Ruby will let the representative know that the test has not been validated for arsenic yet.

• Brown said that Berti sent her a bucket of soil several months ago. She asked whether analyses had been performed on this soil. Berti agreed to respond after going through his files.

ACTION ITEMS

• Sauve and Berti will communicate about using a potassium nitrate solution to perform plant extraction studies on Joplin’s samples. Berti will find out how much sample was collected during the October 1999 sampling event. Sauve will start writing plans for the plant extraction studies.

• Mosby will contact Yang to ask about the samples that were collected in November 1999. Mosby will find out (1) what fraction of the sample was discarded after sieving, (2) how much was sent to Casteel, and (3) how much remains in storage. Mosby will report his findings to Ruby and Ryan.

• A USDA representative may travel to the Joplin site before the end of April 2000 to collect a sample for a rat-dosing study. If such a sampling event is scheduled, Chaney said, it might be possible to collect large samples for all of Joplin’s treatments at that time. Mosby offered to help USDA with the effort. Chaney will contact Mosby if his help is needed.

• Brown will perform in vitro analyses on the 10% compost treatments.

• Conference call participants agreed that Ryan should store the IINERT Action Team’s soil samples. Mosby will contact Yang to talk to him about this.

• Ruby will contact a representative from the Edenspace Systems Corporation to let him know that in vitro tests have not yet been validated for arsenic.

• Berti will let Brown know whether analyses were performed on a bucket of soil that he sent her several months ago.

• ERG agreed to set up the next conference call for April 24, 2000, between 4:00 and 5:00 EDT.