SUMMARY OF THE REMEDIATION TECHNOLOGIES DEVELOPMENT FORUM
IN-PLACE INACTIVATION AND NATURAL ECOLOGICAL RESTORATION
TECHNOLOGIES (IINERT)
SOIL-METALS WORK GROUP MEETING
SOIL AMENDMENTS FOR LAND RESTORATION WORKSHOP

Coeur d'Alene, Idaho
June 23, 1999

INTRODUCTION AND WELCOME
Bill Berti, DuPont
Jim Ryan, U.S. Environmental Protection Agency (EPA)

Bill Berti and Jim Ryan, co-chairs of the Remediation Technologies Development Forum (RTDF) In-Place Inactivation and Natural Ecological Restoration Technologies (IINERT) Action Team, welcomed participants (see Attachment A) and outlined the day's events. Berti said that this meeting marked the third day of a 4-day workshop. Participants spent the previous days as follows:

• June 21. A Land Restoration Workshop was organized and presented by the University of Washington College of Forest Resources' Drs. Chuck Henry and Sally Brown and the U.S. Department of Agriculture's Dr. Rufus Chaney. (Dr. Henry has created a Web site that includes much of the material that was presented during the workshop. It can be located at http://weber.u.washington.edu/~clh/iinert.html.)

• June 22. Participants attended a field trip to the Bunker Hill Site in Kellogg, Idaho.

Berti said that much of the agenda for the June 23 meeting involved follow-up discussions of what had been observed and learned during the Bunker Hill field trip, as well as various ecosystem restoration efforts conducted at that site and another in Leadville, Colorado. Berti said that the 4-day workshop would conclude on June 24th with a field trip to Trail, British Columbia.

ECOSYSTEM RESTORATION—DEFINITIONS
Mark Sprenger, U.S. Environmental Protection Agency (EPA)

Mark Sprenger provided an overview of how the ecological risk assessment (ERA) process, in principle and practice, fits into the framework of soil remediation."How do you know you're not making things worse through remediation?" he asked participants. The ERA process, he said, is designed to help scientists stay focused to avoid doing just that. In many respects, soil remediation is an ERA process, and thus should be structured like one to ensure that scientists ask the proper questions and establish realistic assessment endpoints and objectives.

Questions To Ask When Approaching Remediation From an Ecological Risk Perspective

Sprenger outlined a number of basic questions that should be asked when beginning a remediation effort.

• Is there an ecological risk? (An environmental impact does not necessarily indicate that there is a risk to necessary habitat or local species, Sprenger said.)

  —	If there is a risk, is it toxicological or "physical" (e.g., nutrient retention, soil retention)?
  —	What components of the ecosystem are at risk (are you facing a dissolved metal problem or a lead ingestion problem)?
  —	What are the causative agents of the risk?

• Would the treated or revegetated tailings/mine waste pose an ecological risk? (What are the tradeoffs? Both sides of the equation must be evaluated.)

• If there is an ecological risk originating from the treated or revegetated tailings/mine waste:
  
  

  —	Have the risks been reduced relative to pretreatment conditions? Which risks have been reduced?
  —	Have new risks been created through the treatment or revegetation efforts?

To answer the above questions, Sprenger said, an ecological risk assessment must be developed to allow for:

• An evaluation of the "action's" effectiveness

• Improved risk communication (with colleagues, the media, and public concerns)

• Focus for a monitoring plan

Ecological Risk Perspective on Tailings/Mine Waste Amendment and/or Revegetation Projects

Sprenger said that unvegetated tailings/mine waste create several ecological risk issues:

• The original material may pose a risk.

• The amendments themselves typically contain metals and/or other constituents above levels of ecological concern.

• The form/bioavailability of the contaminants may change.

• New routes of environmental exposure may be established.

• Contaminants have not been removed.

• There is a lack of documentation (hard evidence) that the "remedy" is sustainable. Only long-term monitoring will determine this. However, the cost of a long-term monitoring plan may be a barrier to acceptance—if a $1 million study is needed to prove the effectiveness of a remedy, other options may become more attractive (even if they are less environmentally effective).

• Public perception of a remedy is also a crucial issue. (Some treatments leave "scars" on the land that may not pose an ecological risk, but which anger local communities, damage recreational economies, etc.)

Sprenger said that some typical assessment endpoints for mining sites include, but are not limited to, the following:

• Health of adjacent water bodies

• Improved soil functioning

• Health of rooted-plant communities

• Avoidance of food-chain transfer of contaminants

According to Sprenger, incorporating the ERA process into soil remediation planning and implementation efforts helps to focus them: it forces ERA managers to clearly identify the questions they are trying to answer. ERA forces risk managers to look at the process from all sides, consider unanticipated outcomes, and other complicating issues during the planning process. In this way, risk managers can avoid costly corrective measures and manage public relations issues in a more up-front and straightforward manner.

ECOLOGICAL RESTORATION—GOALS AND LEGAL MANDATE
Earl Liverman, EPA

Earl Liverman spoke to the group about the difficulties of balancing time constraints, community concerns, and funding limitations when drawing up a remediation strategy. Human health and ecological issues go hand in hand, but sometimes ecological issues are the bigger concern; despite this reality, when human health issues are not the most pressing, it can often be difficult to get community backing to address less apparent ecological issues.

Efforts Taken at the Bunker Hill Superfund Site

Endpoints

The objectives—or endpoints—of the remediation efforts at Bunker Hill were to create stable wildlife communities, stable flood plains, and sheltered habitat. Liverman prefaced his remarks by stating that the Bunker Hill remediation work is ongoing, and therefore the EPA does not yet know when their objectives will ultimately be achieved.

Gulches

Liverman said that decades of mining-related activities have impacted gulches in the area around Bunker Hill. EPA has attempted to remediate these detrimental effects by:

• Excavating contaminated soil material from the area

• Restoring disturbed areas such as low-flow and high-flow channels

These steps are intended to address water quality issues and erosion, Liverman said. They are also aimed at preventing recontamination of downstream areas.

Hillsides

Damaged hillsides are often more difficult to remediate, Liverman said. "Just to get to them we may be damaging the very thing we are trying to restore," he said. To avoid creating additional problems, he said, risk managers had to consider new approaches. "We don't want to lose available soil or allow the downstream motion of contaminants due to further erosion," he said.

Flatlands/Flood Plains

Liverman said that officials decided to remove contaminated material on area flats to help stem contamination of surface and ground water. Wishing to pursue an aggressive cleanup and recreate suitable habitat, Liverman said, EPA decided to reflow parts of the river and recreate the wetlands. They created an overflow channel to provide water to those wetlands, and regraded disturbed areas by importing soil material from prairie lands. Risk managers worked to preserve as much vegetation as possible, in addition to conducting a planting program.

Upstream Issues

When it is time to begin dealing with upstream issues, EPA will have to be extremely careful not to recontaminate areas that have already been treated, Liverman said. One of the main concerns is how to avoid remobilization of contaminants. Fluctuations in the river system that runs near the site are difficult to predict and nearly impossible to prevent.

Other Challenges

Liverman said that the Bunker Hill Site is large, crossing three county and two state lines and involving three Indian tribes as well as other local communities. By involving local communities, EPA has learned that the public is mainly concerned with aesthetics, noise and access to the river—issues that are a considerably lower priority to risk managers. However, to be successful in the long run, risk managers must be sensitive to public concerns, Liverman said. As a result, EPA refocused some of its funds to address some of these issues.

ECOSYSTEM RESTORATION IN LEADVILLE, COLORADO
Harry Compton, EPA

Harry Compton, standing in for Mike Zimmerman, presented an overview of the remediation efforts taken at the Leadville Superfund Site in Colorado. Compton presented a number of slides showing the various efforts underway at the site.

Overview of Leadville

Compton said that contamination of the Leadville site began in the 1870s, when gold and silver mining took place in the region. It became an NPL (National Priorities List) site in the late 1980s. Many abandoned mines on the site polluted a nearby stretch of the Arkansas River via the California Gulch which runs through Leadville. Leadville is located high in the Rocky Mountains at 10,400 feet. Because of its elevation, the area enjoys approximately 50 days of frost-free weather each year, making the construction and growing season short and difficult.

It is theorized that over the last 100 years, mine tailings impoundments and other sources of tailings were eroded down the California Gulch into the Arkansas River. Tailings high in heavy metals have been deposited on the banks of the river over the years. These tailings are toxic to vegetation and have led to streambank erosion.

The Arkansas River starts at the Continental Divide and flows south to Pueblo, Colorado, then through Kansas, Oklahoma, Arkansas, and into the Mississippi River just north of Greenville, Mississippi. Its waters are a major source of irrigation, municipal, and industrial uses in all of these states. In the upper reaches, the Arkansas River also has recreational uses (rafting, boating, and fishing).

Upper Arkansas River Fluvial Tailings

Compton said that EPA Region 8 was invited by the Lake County Soil Conservation District (LCSCD) to study the damage to the river over the course of many seasons. The LCSCD sponsored the formation of a group of stakeholders to address the damage to, and restoration of, the river. Representatives from the U.S. Department of the Interior (DOI) (specifically the U.S. Fish and Wildlife Service) mining companies, Colorado state officials, local landowners, and EPA officials worked together to develop a restoration plan for the river. The group decided to begin remediation efforts along a stretch of the river from where it meets the California Gulch to a water sampling station 11 miles downstream.

Identification

During the summer of 1996, EPA began an assessment process to identify and characterize the hazardous materials located in the flood plain adjacent to Leadville. Compton said that EPA identified 101 areas at that time, and an additional 48 during the summer of 1998, that were laden with heavy metals. These areas were adjacent to the river and scarified of vegetation. The EPA team used aerial photographs and prescreening to identify the areas.

Characterization

Compton said that the identified areas were characterized according to:

• Measurement

• Sampling

• Visual toxicity

• Cut banks (rills and gullies)

• Visible erosion

• Depth, area and volume

• Dead vegetation (surface salts)

Sampling Analysis

Compton said that a number of different methods have been used to determine the level of contamination in each of the identified areas:

• X-ray fluorescence spectrometer

• Laboratory metals testing

• TCLP (Toxicity Characteristic Leaching Procedure-Method 1310) metals

• Total metals (surface water samples)

After initial sampling was completed, the team found the following metals and contaminant levels: cadmium from non-detectable (ND) levels to 1,000 milligrams per kilogram (mg/kg); copper from ND to 7,800 mg/kg; lead from 58 to 16,000 mg/kg; manganese from ND to 35,000 mg/kg; and zinc from ND to 115,000 mg/kg.

Confluence of California Gulch with Arkansas River

Compton said that efforts to stem contaminated flows into the Arkansas River from the California Gulch are expected to take a few more years. Already, contamination has been drastically reduced.

Slide Presentation

Compton showed participants a number of slides that illustrate the extent of the problem: the damage that has occurred in the flood plain; evidence of tailings along river embankment; photos of precipitating salts within the flood plain; pooled rainwater high in sulfur; embankments scarified of vegetation; and others.

Using Biosolids To Remediate the Soil

Compton said that biosolids were used to remediate the soil in some areas. The biosolid "recipe" for the wetland areas was 20 tons per acre of lime and 20 tons per acre of compost.

Revegetation Efforts

Compton said that pilot sites were seeded during the late summer and fall of 1998 but, due to dry conditions, their vegetative output was very sparse in the spring. The team is considering new plans to reseed in the near future.

Future Efforts

Compton said that EPA Region 8 recently approved another Superfund Removal action for an additional 20 acres of land near the Leadville site using in situ soil amendments. Biosolid pellets and compost with lime are expected to be the main ingredient for that new project.

ECOSYSTEM RESTORATION FROM THE U.S. FISH AND WILDLIFE PERSPECTIVE
Dan Audet, U.S. Fish and Wildlife Service

Dan Audet described the work he and his colleagues have done to reduce lead poisoning of waterfowl in the Coeur d'Alene Basin. His presentation consisted largely of slides, which showed aquatic ecosystems and specific problems related to waterfowl and lead poisoning.

Audet explained that sediment ingestion is the primary exposure route for lead to animals. Various species of birds, such as Canadian geese, are equipped with long necks or bills that enable them to hunt for food hidden in up to 2 feet of lake bottom sediment. While this adaption has helped them sustain vibrant populations, it is also now exposing them to lethal doses of lead in some situations.

Digging birds are not the only species at risk for lead poisoning, Audet explained. Songbirds that feed on the edges of wetlands are also at risk, as are ospreys and other predator birds (such as eagles which feed on fish that previously fed on sediments). Even species that are far removed from contaminated river and lake beds can be at risk: tree swallows, for instance, feed on insects that breed on contaminated waters.

Treatment Options

Audet explained the various options that the U.S. Fish and Wildlife Service considered to reduce the amount of lead in the area. Removing contaminated soil, via excavation did not seem practical, given that 7,000 acres of open habitat and wetlands were contaminated. Capping the area was another possibility, but that seemed counter-productive, given the goal of maintaining habitat while making the area safe. The use of biosolids was another option, but there were concerns about their impact on area water quality; adding new nutrients to an already nutrient-rich environment can cause serious problems.

Instead of choosing any one of these strategies, the Fish and Wildlife Service decided to conduct a series of mitigations using each strategy where it seemed most appropriate.

Issues Posed by Wetlands

Audet explained that the wetlands in the Coeur d'Alene Basin contain three kinds of sediment:

• Emergent wetland sediment

• Deep water sediment

• Detrital mats that float and trap sediment

Natural water fluctuations in the area are extreme, Audet said. This has led to unpredictable sediment movement.

The Fish and Wildlife Service first determined the lead concentration in sediment in different areas, where different kinds of birds were feeding, and on what vegetation they were feeding. They also analyzed the lead concentration in bird feces in different areas. This information helped them to determine which areas to prioritize.

Audet explained that the Fish and Wildlife Service has been struggling to identify how to expand the available habitat through remediation without increasing the danger of lead poisoning as well. Due to the extreme water fluctuations in the region, officials were concerned about creating an appealing habitat that may ultimately become recontaminated.

METAL AVAILABILITY AND WETLAND PLANT ESTABLISHMENT IN AMENDED MINE TAILINGS
Pam DeVolder, University of Washington

Pam DeVolder, a graduate student at the University of Washington, described her research on the effectiveness of using organic residuals to remediate lead-contaminated sediment. DeVolder chose to conduct her study using sediment from the West Page Swamp at the Bunker Hill Site. West Page is a 28-acre wetland that was used as a repository for mine tailings between 1918 and 1929. Those tailings have been located at depths of 18 inches to 10 feet. There is limited vegetation in some areas. DeVolder identified high metals concentrations in the non-vegetated sediment chosen for her control sediment: lead was found at concentrations between 18,000 and 39,700 mg/kg; zinc at concentrations between 8,500 and 25,600 mg/kg; and cadmium at concentrations between 86 and 249 mg/kg.

Objectives of DeVolder's greenhouse study are:

• Test the effectiveness of using organic residuals to remediate lead-contaminated sediment.

• Measure the effects of pH, redox, and bioavailable lead on sediment.

• Observe establishment, rooting patterns, and lead uptake of vegetation under various conditions.

DeVolder's hypotheses were that revegetation would be more rapid in treated areas and that the bioaccessibility of lead will be reduced in treated areas as well.

For her study, DeVolder used two common wetland plants, arrowhead and cattails. She planted some plants in control pots containing non-treated sediment, and others in test pots containing 4 inches of sediment, 6 inches of amendment containing three parts biosolids compost and one part wood ash, and 2 inches of water on top. (The plants were planted in the amendment layer.) DeVolder added sulfur to both the control and test pots at two different rates. DeVolder takes periodic measurements of soil redox potential, pH, and pore water analysis at three levels. The study will take place over a 12-week period.

SOIL CHEMISTRY AND THE USE OF MICROBES
Frank Rosenzweig, University of Idaho

Frank Rosenzweig, a microbiologist from the University of Idaho, presented current research on the microbiology of the Coeur d'Alene Basin. Rosenzweig presented detailed information concerning the nature of the microbiology communities in the St. Joe and the Coeur d'Alene deltas. This sediment is rich in microbial life, according to Rosenzweig, and to ignore those communities when designing and implementing a soil remediation effort would be a mistake.

"We don't yet have a predictive model as to what would happen if these sediments were enriched with nitrogen, phosphorous, or carbon, for instance, or even sustained aeration," he said. These sediments are not inert materials. The microorganisms they contain respire certain metals, such as oxidized iron, just as humans breathe air. To disrupt this habitat by removing all of those metals could have dire consequences as yet unseen. "If you change the valence state and solubility of these metals," Rosenzweig said, "it will affect these microorganisms. Not taking this into account is a recipe for disaster."

RESEARCH AT THE LEADVILLE SITE
Mark Sprenger, EPA

Mark Sprenger returned to make an additional presentation, this time focusing on the monitoring and evaluation work that EPA is conducting at the Leadville site in Colorado. Sprenger briefly described how the EPA is bringing the ecological risk assessment (ERA) perspective to its long-term evaluation of efforts to remediate this site. The agency will be analyzing the physical, chemical, and biological properties of the remediated soil over the next 5 years to determine the effectiveness of its treatment.

Sprenger said that EPA has conducted several physical analyses of the amendment plots, measuring such characteristics as:

• Grain size

• Moisture content

• Water-holding

• Specific gravity

Sprenger said that EPA's chemical analyses of the amendment plots target:

• Analyte list metals (total, water leachable, exchangeable).

• TCLP metals (availability under extreme environmental conditions).

• MEP (Multiple Extraction Procedure-Method 1320) metals (long-term availability).

• pH, acidity and limestone requirement.

• Available nutrients (nitrogen, phosphorus, sulfur, chloride, boron, potassium, magnesium, calcium, zinc, manganese, copper, iron, and molybdenum).

• Total organic carbon.

• Cation exchange capacity and exchangeable potassium, magnesium, and calcium.

• Soluble salts.

Sprenger said that EPA's biological analyses include:

• Determining the number of microarthropods present.

• Analyzing the population and diversity of the soil community (bacteria, fungi, protozoa, nematodes present).

• Toxicity and bioaccumulation in earthworms.

• Toxicity, growth, and bioaccumulation in plants.

Sprenger presented the data collected on all of the above indices. EPA found that the main contaminants of concern were cadmium, copper, lead, manganese, and zinc.

Among the significant findings concerning soil community organisms:

• No flagellates were collected.

• Only 7.3 amoebae/GDW (gram dry weight of soil) collected at one location.

• No ciliates were collected.

• Only 0.1 nematodes/GDW soil collected at the same sample location where 7.3 amoebae/GDW were found.

• All nematodes collected were bacteriovores.

• No microarthropods were collected.

• Dehydrogenase (soil enzymes) were at concentrations below the detection limit.

Results from the bioassays were even more striking, according to Sprenger. EPA found that whole soil samples caused a 100 percent mortality rate in earthworms within the first 48 hours of exposure. The LC50s (i.e., concentration that caused 50 percent mortality) for earthworms after 14 days of exposure were 54.8 percent soil concentration; 9.3 percent soil concentration; and 36.2 percent soil concentration at various sample collection locations. Lastly, no ryegrass seeds germinated in samples collected from two site locations, including one sample where the LC50 for earthworms was 36.3 percent soil concentration within 28 days of exposure.

In conclusion, Sprenger highlighted the importance of taking an interdisciplinary approach to both remediation and the monitoring and evaluation processes that follow any cleanup action.

IINERT ROUND TABLE DISCUSSION

After the lunch break, about a dozen workshop participants returned to discuss future efforts. The first action item decided on was the creation of an extended IINERT mailing list, one that would include active IINERT members as well as other people in academia, industry, and government who might help the IINERT Action Team achieve its goals. They also agreed that more informational sharing is needed. It is important that members share information on remedies that appear to be working so that the team can begin building a database of statistically valid samples for the purpose of enlarging the available number of presumptive remedies. Why should we always be starting from scratch, reinventing the wheel? asked one participant.

Presumptive Remedies: Are There Too Many Presumptions?

Questions surrounding presumptive remedies—how useful and successful, in reality, are they?—dominated much of this hour-long discussion session.

EPA has issued a number of presumptive remedies for cleaning up Superfund sites. (The agency's list of presumptive remedies, including its list of nine criteria for adding to that current list, can be found at http://www.epa.gov/superfund/resources/presump/index.htm.) While site managers are not technically obliged to use EPA-approved presumptive remedies, doing so greatly reduces the length and complexity of the permitting and approval processes as well as the paperwork involved. However, the members attending this session expressed concerns that these incentives have resulted in fewer site managers employing new and innovative technologies, even when those technologies may be more effective. In other words, the presumptive remedy approach that EPA has taken to ease the permitting process and encourage more cleanups may actually be discouraging the use of new and innovative techniques.

To become an EPA-approved presumptive remedy, an innovative technology must be used at three full-scale sites. The group brainstormed ways to expand the current list of presumptive remedies. The first barrier appears to be related to information sharing—or, more specifically, the current lack of information-sharing. Participants mentioned a number of specific sites where one or another remediation technology is being used. Because EPA requires statistically valid samples in order to determine the effectiveness of a given new technology, the participants came up with a list of sites around the country from which such data is currently available.

(For more information on EPA's policies and procedures concerning presumptive remedies, visit www.epa.gov/oerrpage/superfund/resources/presump/pol.htm.)¹

Quick-Reference Fact Sheet

The participants also agreed that a quick-reference fact sheet should be developed to help site managers answer questions from the public and the media concerning their cleanup efforts' effect on human health and the environment. This technology fact sheet would contain hard data to support claims of reduced exposures and incident of health risks. It would be an educational, as well as a public relations, tool.

The participants considered a number of ways to gather information for the fact sheet. One would be to hold a workshop to pull together raw data from various sources. Another would be to conduct a conference call, or include the request on the agenda of conference calls already scheduled. Bill Berti also suggested the possibility of sending out a request for data to IINERT members on the e-mail list serv.

Attachment A

Final Attendee List

RTDF IINERT Soil-Metals
Action Team Meeting

Coeur d'Alene Inn & Conference Center, Coeur d'Alene, Idaho
Bunker Hill Site, Kellogg, Idaho
Trail Site in Trail, British Columbia, Canada
June 21-24, 1999

Final Attendee List

*speaker

1. An EPA meeting was held on August 8, 1999, (subsequent to the IINERT conference in Coeur D'Alene) to discuss the role of the IINERT Team in developing a presumptive remedy. It was determined that the Remediation Technologies Development Forum, of which the IINERT Team is part of, cannot develop a presumptive remedy as part of its joint work with EPA. Presumptive remedies developed by EPA necessitate broader, more inclusive public involvement. However, IINERT may compile jointly developed technology information and submit it to EPA for review. EPA may use this information to assist in formulating guidelines, develop engineering bulletins, or to support other new technology initiatives.