Remediation Technologies Development Forum (RTDF) In-Place Inactivation and Natural Ecological Restoration Technologies (IINERT) Soil-Metals Work Group Meeting Summary

Wilmington, DE
July 29-30, 1996

July 29th

Welcome and Overview of the RTDF IINERT Soil-Metals Work Group

Bill Berti (DuPont), co-chair of the Remediation Technologies Development Forum (RTDF) In-Place Inactivation and Natural Ecological Restoration Technologies (IINERT) Soil-Metals Work Group, welcomed the participants to the third meeting of the Work Group. Mark Searles (SCG) provided a brief overview of the RTDF and of the past Work Group meetings. Mark informed the group that the RTDF was established in 1992 by EPA after industry representatives met with the Administrator to identify ways of working together to solve complex hazardous waste remediation problems. He indicated that RTDF meetings are open and that all interested organizations are welcome to participate. RTDF members include chemical, petroleum, and pharmaceutical companies, various manufacturers, federal agencies, national laboratories, research centers and institutes, and universities. Mark indicated that the RTDF forges public-private partnerships to develop and improve hazardous waste remediation technologies. He noted that participating organizations share knowledge, experience, equipment, facilities, and proprietary technology to address mutual remediation problems. The RTDF establishes action teams that bring members together to work on common remediation problems.

The IINERT Work Group held its kick-off meeting in November 1995 and has since built upon honed its mission and objectives. Mark provided the following mission statement for the Work Group:

To develop and demonstrate in-place technologies to reduce/eliminate risks to human health and the environment of lead and other metals and metalloids in soil and other surficial media. These in-place technologies must be ultimately acceptable to the public and regulatory communities.

Overview of Joplin, MO Site

Mark Doolan (EPA/Region VII) provided an overview of a site in Joplin, MO (Joplin), where remediation efforts are underway by EPA/Region Vii and the Missouri Department of Natural Resources (MDNR). Mark indicated that the primary contaminants of interest in the locality are lead and zinc. There are approximately 6,000 acres of mine tailings in the area. Mining was conducted until the early 1900's, and smelting operations continued until the 1940's. The city of Joplin is populated by 50-60,000 residents, and approximately 3,000 residential yards with elevated levels of lead, zinc, and cadmium. Mark indicated that 250 yards have been excavated to a depth of 12". The residences with the highest levels of contamination are being treated first. Mark noted that although excavation of contaminated yards has begun, EPA is interested in employing a treatment technology that does not require excavation. Residences leadcontamination above 2,500 ppm have been treated and Mark suspected that all residences with lead contamination above 2,000 ppm will be excavated by the time field treatments are ready for the field.

A treatability study has been performed for the Joplin. A 1-acre site, which is 3-4 blocks from the primary smelter, has been identified as a candidate field site to investigate various treatment technologies. Mark indicated that the lead levels at the candidate field are approximately 1000-5000 ppm Pb. He noted that soil samples were collected and provided to the University of Michigan for analysis. A variety of chemical and physical analyses were performed in addition to a determination of the soil heterogeneity. Lead bioavailability was determined to vary significantly, with values as high as 30%. Mark felt it would be beneficial for the IINERT Soil-Metals Work Group to work with regional officials and other interested parties to develop a full-scale treatability study for the site. A microswine study is planned for late Fall 1996- it was noted that a variety of surrogate research, in-vitro studies by DuPont, rat studies by USDA, others, is being performed. Mark was hopeful that the surrogate research would identify an analytical method for determining lead bioavailability which would be less time-consuming, less resource intensive, and easier to perform than microswine studies. A participant noted that it costs approximately $25K per sample to perform a microswine study. Mark indicated that he welcomes participation/involvement from the IINERT Soil-Metals Work Group. He also noted that soil has been collected and homogenized, and indicated interested participants may acquire soil if they so choose.

Overview of the Action Team Development Process

Dick Jensen (DuPont) provided an overview of the process by which a RTDF Action Team develops. An Action Team does not necessarily follow the path outlined by Dick- he noted that the path presented is loosely based on the path taken by the Bioremediation Consortium. The following steps were identified in the development process of an Action Team whose goal is to perform a cooperative field effort:

1. Gathering of Interest
2. Development of Purpose and Mission
3. Starting Point- What is Known
4. Identification of Tasks and Experiments to be Performed
5. Division of Tasks
6. Legal Agreement(s)
7. Begin Work.

Dick suggested that the IINERT Soil-Metals Work Group is currently at step 3. The Work Group agreed and expressed hope that the further progress could be made throughout the meeting. He provided additional information regarding the development process. He noted that the agreements are structured to address the concerns of all parties involved, including such issues as program mission, confidentiality, program inventions, scope of work, warranties and indemnification, and termination. The division of tasks/responsibilities was identified as an important step as it identifies commitments on the part of the participating organizations. Dick indicated that it is beneficial to develop a comprehensive list of tasks, which includes a deliverable and approach statement. The level of effort and responsible party must also be identified for each task.

Discussion of Work Group Executive Summary

Dick Jensen initiated a discussion of the Work Group executive summary and provided a summary of the development process. Dick identified the following steps:

• Obtained "snapshot-in-time" of IINERT Soil-Metals Work Group, and other information pertaining to in-place, inactivation technologies
• Categorized information- known facts, hypotheses, measurements, assignable activities, and general information
• Developed Executive Summary, efficacy statement, list of known facts, list of hypotheses, discussion and diagram of surrogacy, and initial development of Project Task and Funding Chart
• Provided draft to Work Group members for review and comment.

Discussion of Hypothesis

Bill Berti initiated a discussion of the six hypotheses developed for the Work Group. The hypotheses identify the fundamental concepts which the Work Group hopes to prove through its collaborative efforts.

Participants were asked to identify which of the hypotheses they would like to actively develop.

Hypothesis I. Prior to widespread use of IINERT approaches on lead soils, public trust must and can be garnered through careful scientific studies.

a. Field demonstrations are useful for scientific studies to help develop and prove technologies.

b. Field demonstration sites are valid resources and an integral part of gaining scientific and public acceptance of the technology.

c. Representatives of political and social groups, such as those who have participated in the U.S. lead risk reduction debate, can help suggest studies to address questions about the acceptability of in place inactivation.

A participant felt that education is important to the acceptance of a new technology. Because a number of lead-contaminated sites are within populated areas, it is important that the local communities are comfortable with IINERT technologies. There are varying levels of knowledge/interest from the public. Community figures often seek input from regulators regarding the safety and effectiveness of a new technology. Dan Vomberg (Doe Run) mentioned that Doe Run has developed videos as an outreach method, and in some cases have targeted an audience of one to reach critical audiences. Mark Doolan indicated that a Citizen Task Force and a Technical Advisory Group (TAG) has been identified at Joplin, MO and suggested that it would be beneficial to coordinate with these two groups. Mark noted that some community members are very involved with the efforts at Joplin and are also cognizant of other pertinent remediation efforts. He also noted that significant outreach efforts were performed to educate the public. Sally Brown (USDA) agreed with Mark, and indicated that community persons were receptive when she visited the site. Rufus Chaney (USDA) suggested that the scientific community should be prominently targeted and noted that peer-reviewed papers would help to meet that end. Jim Ryan indicated that it would be helpful to target regulators so that technologies other than excavation become more acceptable. Rufus agreed, but suggested that scientific papers are necessary to justify a change in policy. A participant suggested increasing the involvement of academia as typically focus on the validity of a science. The Brownfield Initiatives were referenced as an example where involved parties are interested in more cost-effective technologies to treat various contaminants, including lead. Scott Cunningham (DuPont) noted that a significant amount of data suggests that IINERT technologies will work, but this information needs to be communicated. He also noted that there are other resources which could be tapped, such as inorganic chemists, who agree that phytoremediation should work from a thermodynamics perspective. Rufus Chaney agreed, but noted that field demonstrations are needed to validate a technology. The Work Group agreed that it is important to involve all pertinent audiences in the development process so that their concerns may be more easily identified and addressed. Steve Luftig (EPA) and Walt Kovalick (EPA) were identified as two EPA-persons who may be helpful to the acceptance process. Harry Compton (EPA) indicated that he would work with Mark Doolan to keep EPA Headquarters aware of the efforts at Joplin. It was suggested to invite 4-6 'critics' of IINERT technologies to a future meeting so that their concerns could be addressed.

Hypothesis II. Surrogate relationships can be identified/confirmed among Pb availability to humans, pigs, rats, and glassware extractions (single and sequential). These relationships will lead to simpler, quicker, cheaper tests/proofs that will garner the public trust.

a. Rat, weaning pig, microswine, primate and human adult models are equally useful for determining Pb bioavailability in soils, which can be correlated to soil-Pb bioavailability in children.

b. Simple chemical extractions can be identified that correlate well with the results of more complex animal models.

Participants noted that consensus on the "best" surrogate model does not exist. DuPont has performed comparison studies that suggest rats and microswine act similarly as surrogates, although Bill Berti noted that this is based on a limited data set. A participant suggested that primate data is ultimately necessary in those situations where rats and microswine studies are not accepted by the regulatory and scientific communities. A participant suggested that different models could be explored using Joplin soils. It was noted that it would be helpful to compare surrogate models using soil from more than one site. Mark Doolan indicated that an objective of the treatability study is to determine a new benchmark for lead-bioavailability, which in turn, would identify which sites would require excavation, and which could be treated with a less costly treatment technique, such as IINERT technologies.

Hypothesis III. Good correlations exist between soil components (e.g., Pb species non-Pb containing components) and the soil-Pb hazard.

a. Soil constituents strongly adsorb, physically entrap, and/or precipitate Pb, limiting the soil Pb hazard.

b. The affect soil components have on the soil Pb hazard can be determined from site/soil specific information.

It was suggested to modify the hypothesis to read, "Good correlations may exist ...". A participant noted that Hypothesis II and IIIare related and suggested that those who develop Hypothesis II coordinate with those who develop Hypothesis III. Jim Ryan noted that the hypotheses are intended to be independent, but encouraged participants to help develop more than one.

Hypothesis IV. Engineered addition of materials to lead contaminated soils will induce the formation of less hazardous Pb forms, providing a practical approach to in-place inactivation.

a. Soil-lead inactivation approaches are sufficiently robust to overcome site-to-site variability and variability within a single site.

a1. Appropriate rates of materials are needed to accomplish a satisfactory level of inactivation can be estimated using simple laboratory studies or measurements. Engineering scale-up techniques/decisions can be incorporated into this.

a2. Soil-lead inactivation approaches can be effectively accomplished in-situ.

b. Soil-lead inactivation approaches will provide a long term reduction in the soil-lead hazard.

Participants agreed that although the cost of implementing a technology was an important factor, it should not be the driving factor regarding the development of a technology. Time often becomes a driving factor in the selection of a remediation technology. Phosphate treatments address the top layer of soil quickly, but typically require additional time to diffuse to lower subsurface regions. A participant noted that the top layer is of most importance as it is of greatest hazard to children. Soil fertility was also identified as a concern- treatments may alter the soil pH, which can subsequently alter the plant growth. Rufus Chaney noted that a community outreach program was implemented at Palmerton, PA, whereby citizens could rent tillers, mulch, and amendments, which proved very cost-effective because the citizens performed the labor to add the soil treatments. He indicated that approximately 70% of the houses volunteered for this. Rufus also noted that excavation costs need to be considered- a convenient dumping site exists at Joplin, MO, but this is not always the case.

Hypothesis V. Ecosystem health concerns are also addressed by IINERT.

a. Measurements that address the impact of soil-lead to human health (bioavailability, plant uptake, leaching to groundwater, speciation) are sufficient to address ecosystem health concerns.

a1. Simple tests can be identified/validated with other measures of the soil-lead hazard (i.e., leachability, plant uptake, etc)

b. Ecosystem health concerns that result from in-place inactivation or can be mitigated thorough proper site management.

Rufus Chaney suggested that adequate data exists which suggests that exposure diminishes as one goes up the food chain. A participant also noted that there is an issue of scale- i.e., should a forest be remediated, which may disturb the ecosystem, or should the contamination remain which poses a continual risk? It was noted that it is often difficult to monitor "wildlife" per se, because animals are not sedentary.

Hypothesis VI. The research and development of IINERT for soil-Pb extends to other soil contaminants as well (i.e., Zn, Cd, Cr, Ni, As, Cu, Se, petroleum hydrocarbons, etc.).

A participant suggested that arsenic and petroleum hydrocarbons may be outside of the scope of the IINERT technologies- these contaminants are traditionally reduced and are not stabilized, which is a variance from the other contaminants. Bill Berti agreed, but felt that these contaminants should not be forgotten about. One specific treatment may not address all contaminants at a site. Participants also questioned if it would be in the Work Group's best interest to initially target two or three contaminants. Zinc and cadmium are present at most mining sites, arsenic and cobalt are present at most western United States sites. Scott Cunningham suggested that lead remain the focus of the Work Group. The Work Group agreed, but noted that the other contaminants should also be a consideration. Dave Mosby noted that other contaminants, in addition to lead, are present at elevated levels at Joplin.

It was suggested that subgroups be identified to develop each of the six hypotheses. Each subgroup should consider:

• What is the appropriate time-line?
• What levels of funding are required?
• Who should be included in the subgroup?
• What is the appropriate audience?

The following subgroups were identified to investigate each of the hypothesis:

It was agreed that Hypothesis VI was an integral part of Hypothesis I-V. It was therefore deleted as a separate hypothesis, but will be addressed by each of the remaining hypotheses.

July 30, 1996

Opening Remarks

Bill Berti welcomed participants to the second day of the meeting. He suggested that the hypotheses be revisited to identify any outstanding issues. Bill expressed hope that the hypotheses would be further developed by the subgroups during the next month. He asked participants to consider the hypotheses, and to provide the subgroup leaders with any concerns regarding the hypotheses.

General Discussion

Bill noted that a number of proprietary stabilization technologies exist and indicated that Jeff Newton (IWT) has expressed a willingness to investigate soil using a IWT proprietary treatment technology. The IINERT Work Group would be able to independently determine the effectiveness of the treatment. Dan Vomberg expressed reluctance to perform analysis on soils treated by an organization outside of the Work Group and several Work Group members concurred. Jim Ryan indicated that the majority of proprietary techniques with which he is familiar are not structured toward lead-bioavailability, which is of interest to the Work Group. Dick Jensen mentioned thathe provided contaminated soil to Jeff, who performed remediation treatments and that results by an independent laboratory, were favorable. The Work Group agreed that, if appropriate, proprietary technologies should be evaluated as possible treatment techniques. It was also agreed that issues pertaining to the use of a proprietary technology should be clearly addressed. A participant suggested that it may be in the best interest of the Work Group to use a proprietary technology as it may reduce duplication of efforts.

Mark Doolan suggested that a subgroup be identified to investigate delivery methods for a treatment. He noted that there are several methods to delivery treatments, each of which has advantages and disadvantages. Dan Vomberg suggested that it may be preferable to design a delivery method tailored to the needs of the field program. A number of factors must be considered regarding delivery methods- the depth to which the treatment must be delivered was identified as a key consideration. Participants agreed that, in general, the cost of a delivery method will increase as the desired depth increases. The Work Group agreed to form a Delivery Systems Subgroup and the following members were identified:

Delivery Systems Subgroup

Bob Blanchard
John Carter (Doe Run)
Cole (USDA)
Dave Mosby

The Work Group agreed that the delivery method should be cost-effective. It also agreed that natural diffusion processes should be considered when evaluating a delivery method.

Continued Discussion of Hypothesis I. Hypothesis I will serve to identify the parties which should be involved with the developmental process. Jim Ryan agreed that numerous parties should be aware of the developmental efforts, but cautioned that key parties should be directly involved so that the effort does not become diluted. It was agreed that each of the respective Hypothesis subgroups should identify outreach avenues so that the hypotheses may be reviewed by the appropriate parties and Shahid Mahmud (EPA) suggested that the Western Governors Association (WGA) may be an appropriate body to review Work Group documents. It was suggested that each hypothesis subgroup should develop a white paper for review. It was agreed that the white papers should include a list of tasks required to prove the hypothesis. It was agreed to modify Hypothesis I to read, "...scientifc studies and communication of these concepts."

Continued Discussion of Hypothesis IV. It was agreed that cost-effectiveness was an important component of an IINERT technology. Accordingly, it was agreed to develop a new substatement, IV.c, to explicitly state the importance of the cost-effectiveness of a technology. It was also agreed to develop a fourth substatement, IV.d, to explicitly state that the technology should not duplicate existing technologies.

Overview of USDA Research Efforts

Sally Brown (USDA) provided an overview of USDA research performed on various soils. She investigated soils provided by Dan Vornberg as well as soils provided by Mark Doolan. Three "Doe Run" soil samples were collected from calcareous lead/zinc mine tailings and Sally noted that a primary remediation objective for the Doe Run site is to promote revegetation. The following soil properties were provided:

The soils were amended with Compro at 10% dry weight. Compro is a biosolid compost, which is high in iron and lime. Sally provided the following results for the plant growth:

Sally noted that lead levels were significantly lower in the 3 amended soils. In response to a participant's question, she indicated that the increase in zinc and cadmium in the composted soils is not necessarily a concern- the levels are within expected values for healthy grasses. She also noted that the study was designed to maximize the uptake of lead.

Sally also provided an overview of the studies performed on Joplin, MO soils. The soils were collected from a residential area, and sampling indicated that lead concentrations on the site are variable. The site measures 137' x 154', and lead levels from 5350 mg/kg to 1111 mg/kg were measured in the upper 3", and values for the depths 3-6" were reported as 1998 - 4824 mg/kg. It would be difficult to collect soils at a greater depth as the subsurface becomes rocky/rubble-filled. Several amendments were investigated to reduce the lead availability. Sally indicated that Compro/iron/lime amendment provided the best results, but indicated that the other amendments gave favorable results as well. Sally indicated that there is an phosphate run-off potential with some of the treatments and that mulching or other measures may be necessary to address the possibility of run-off. Additional studies focusing on keeping the pH above 6 so that indigenous vegetation will flourish may be helpful.

General Discussion

It was suggested that a common in-vitro test, which mimics the biological processes, be identified. It was noted that the in-vitro methods developed by John Drexler and by Michael Ruby are fairly time consuming and would require a number of months to screen candidate treatments. It was suggested to perform a "quick and dirty" method so that a greater number of treatments could be screened in a shorter period of time. Sally Brown agreed to circulate the analytical method used for the soil studies she performed to the Work Group for information purposes.

The Work Group agreed to identify common treatment and a participant asked if a control is a sufficient standardization mark between laboratories. Mark Doolan noted that the microswine feeding study will begin in November 1996; it would therefore be helpful to determine which treatments to be used in the next 2 weeks considering treatments require 1-3 months before they are ready for the field. Craig Boreiko suggested that the hypothesis subgroups work in consideration of Joplin, MO as it appears to be time sensitive. EPA expects to begin work with treatments by October 1, which will allow field work to begin in Spring 1997. It was preferred to coordinate USDA's efforts with those of EPA and Rufus Chaney indicated that he has some leeway regarding the timing and scope of the USDA efforts.

Mark Doolan felt that compost may be difficult to implement because of general perceptions. Rufus Chaney suggested that perceptions may be more positive if a sample were provided and indicated he would provide a sample to Mark.

Discussion of Joplin Scope of Work

Dave Mosby provided the Work Group with an overview of the Scope of Work (SOW) to be performed at Joplin. Bench scale studies will be performed to identify the most promising treatments. The bench scale studies will be used to screen several candidate treatments. Two treatments are expected to be investigated via a microswine study. The microswine study will be performed and is expected to follow the EPA/Region VIII protocol. A control, lead acetate addition, and treatments at three amendment levels will be investigated. Dave noted that 5 microswine are used per test unit, such that 25 microswine will be used per treatment investigation. The microswine study is expected to require 3-4 months for completion.

Mark Doolan agreed to determine how much soil he has available, and what portion could be used by Work Group members.

It was noted that the reaction rate once the treatment is emplaced is dependent upon the kinetics, includingthe dissolution of phosphorous and lead. Dave Mosby noted that the amended soils fed to the microswine will be highly homogenized to establish a benchmark, against which the field results may be compared. It was suggested that a second site, contaminated with mine tailings, be investigated as well. MDNR and EPA have access to the general area for the second site, Dave Mosby indicated the other Work Group member should be able to have access to it as well. The following outline of activities was developed:

Rufus Chaney indicated that he has developed a draft field plan which could be modified for Joplin.

The following issues were identified regarding the field plots:

• Size of plot
• Mapping for homogeneity
• Lay out of plots
• Initiate treatments
• Incorporation Technologies

The Work Group preferred to leave portions of the plot untreated so that it may be investigated in the future.

It was noted that Bill Berti, Jim Ryan, Rufus Chaney, and Bob Blanchard should be able to perform preliminary treatment evaluations in the near future. Jim Ryan suggested that some duplication of efforts may be necessary so that it may be established if laboratories are in sync or not.

It was suggested that there are 3 methods to apply the treatments. If 2 treatments are to be studied, 6 plots are necessary for the screening. The in-vitro techniques should identify the most promising treatments to be fed to the microswine.

It was noted that blue grass is the preferred vegetation for the area In addition, it was suggested to encourage growth of common garden plants.

Harry Compton indicated that he could provide general field plot information to the Sally Brown and Dave Mosby, who could tailor it to Joplin. Mark Doolan suggested that plots should be approximately 2 m x 4 m. Bill Berti indicated that he could provide an interim in-vitro test method to the Work Group for informational purposes. It was suggested that Michael Ruby review performed in-vitro work. Mark Doolan indicated that he could be a focal point for the efforts at Joplin.

It was noted that a decision needs to be made on whether or not to composite the site. The field conditions are typically more variable than those of the laboratory. Dan Vomberg indicated that Doe Run has been able to homogenize sites fairly easily.

The Work Group preferred that the emplacement technique be fairly simple, such that the public could use at a future date.

It was agreed that the Work Group will focus on Joplin, but will remain cognizant of other activities.

Craig Boreiko indicated that ILZRO Program and Planning Meetings are held in the first week of September. Financial decisions are typically by the end of September. Craig indicated that ILZRO may be able to provide funding if the Work Group were to more clearly define its efforts. ILZRO usually funds pilot/future development programs. Craig indicated that a document identifying current level of effort, as well as requested funding levels is needed within the next two weeks. It should demonstrate the need and feasibilityof the efforts. It was suggested that ILZRO could provide funding to perform a comparison study between rats and microswine. Mark Doolan asked that participants identify their level of effort and provide him with the information.

It was agreed that draft white papers for each of the Hypothesis Subgroups will be developed by Sept 15 for review by the Work Group.

The Treatability Subgroup agreed to meet in Columbia, MO during the first 2 weeks of August.

Bill Berti indicated that he will circulate a document regarding the treatability study to the Treatability Subgroup.

Concluding Remarks

Bill Berti thanked participants for attending the 2-day meeting and felt that significant forward progress was made at the meeting. He suggested that the Work Group meet again in October/November. By that time, the Hypothesis white papers should be further developed. A number of other variables regarding the efforts at Joplin will be defined to a greater extent by that time as well.

The following action items were identified during the meeting:

• Mark Doolan and Harry Compton will work interactively to keep EPA Headquarters up to speed with the efforts at Joplin, MO.
• Sally Brown agreed to circulate the analytical method used for the soil studies she performed to the Work Group for information purposes. IINERT Work Group members will identify additional persons to be involved in the workgroups.
• Hypotheses Work Groups will create white papers for their respective hypotheses for circulation to the IINERT Work Group by September 15th.
• Bill Berti will circulate a shell treatability plan to the Treatability Work Group for consideration.
• The Treatability Work Group will initiate discussions regarding the development of a draft treatability plan during the next two weeks.
• The Treatability Work Group will meet in early September to further revise the treatability plan.
• Mark Doolan will provide Craig Boreiko with a letter delineating identified players and approximate levels of funding, both cash and in-kind contributions, for the planned IINERT Work Group laboratory/field activities.
• Craig Boreiko will seek funding from ILZRO to support the planned IINERT Work Group laboratory/field activities.
• Rufus Chaney will provide a compost sample to Mark Doolan.

RTDF IINERT Soil-Metals Work Group Meeting Participants

Additional RTDF IINERT Soil-Metals Work Group Members