Assessment and Remediation of Contaminated Sediments (ARCS) Program
- Great Lakes Monitoring
- Monitoring and Assessment Water Quality
- Global Earth Observation System of Systems (GEOSS)
Table Of Contents
- Overall Program Scope
- Toxicity/Chemistry Work Group Work Plan
- Risk Assessment/Modeling Work Group Work Plan
- Engineering/Technology Work Group Work Plan
- Communication/Liaison Work Group Work Plan
- Appendix A
- Appendix B
- Appendix C
- Appendix D
1992 Work Plan
The 1987 amendments to the Clean Water Act, in Section 118(c)(3), authorize the U.S. Environmental Protection Agency's (EPA) Great Lakes National Program Office (GLNPO) to coordinate and conduct a 5-year study and demonstration project relating to the appropriate treatment of toxic pollutants in bottom sediments. Five areas were specified in the Act as requiring priority consideration in conducting demonstration projects: Saginaw Bay, Michigan; Sheboygan Harbor, Wisconsin; Grand Calumet River, Indiana; Ashtabula River, Ohio; and Buffalo River, New York (Figure 1). To fulfill the requirements of the Act, GLNPO initiated the Assessment and Remediation of Contaminated Sediments (ARCS) Program. In addition, the Great Lakes Critical Programs Act of 1990 amends the Section, now 118(c)(7), by extending the Program by one year and specifying completion dates for certain interim activities.
ARCS is an integrated program for the development and testing of assessment and remedial action alternatives for contaminated sediments. Information from ARCS program activities will be used to guide the development of Remedial Action Plans (RAPs) for the 43 Great Lakes Areas of Concern (AOCs, as identified by the United States and Canadian Governments), as well as Lakewide Management Plans.
Although GLNPO is responsible for administering the ARCS Program, it is a multi-organization endeavor. Other participants in ARCS include the U.S. Army Corps of Engineers (ACE), the U.S. Fish and Wildlife Service (FWS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Department of Interior, EPA headquarters offices, EPA laboratories, EPA Regions II, III and V, Great Lakes State Agencies, numerous universities, and public interest groups.
The management framework for the ARCS Program is depicted in Figure 2. The Management Advisory Committee has provided advice on ARCS Program activities, and its membership includes representatives from the organizations noted above. Three technical Work Groups identify and prioritize specific tasks to meet the objectives of the Program. These are the Toxicity/Chemistry, Risk Assessment/Modeling, and Engineering/Technology Work Groups. A fourth Work Group, Communication/Liaison, oversees technology transfer, public information and public participation activities. Finally, the Activities Integration Committee coordinates the technical aspects of the work groups' activities.2.0 Objectives
The overall objectives of the ARCS program are to:
- Assess the nature and extent of bottom sediment contamination at selected Great Lakes Areas of Concern,
- Demonstrate and evaluate the effectiveness of selected remedial options, including removal, immobilization and advanced treatment technologies, as well as the "no action" alternative, and
- Provide guidance on contaminated sediment problems and remedial alternatives in the Areas of Concern and other locations in the Great Lakes.
An important aim of the ARCS Program is that the procedures developed and demonstrated be scientifically sound, and technologically and economically practical. The intent is to provide the environmental manager with methods for making cost-effective, environmentally sound decisions. As a result, application of existing techniques is stressed over basic research into new ones. Some developmental work is, however, being undertaken.
To completely assess the causes and effects of contaminated sediments and to fully evaluate the remedial options available, a mass balance of each of the priority areas, including quantification of contaminant loadings from point and non-point sources, would be necessary. Unfortunately, such characterizations could cost several millions of dollars for each priority area. The ARCS Program is using available resources to develop a basic framework for site characterization.
It is important to stress at the outset that ARCS is not a cleanup program, and will not solve the contaminated sediment problems at the five priority consideration areas. The Program will, however, provide valuable experience, that can be used for other projects to actually solve the identified problems.
There are several important aspects of the management of contaminated sediments that will not be fully addressed by the ARCS Program because they were felt to be outside the main objectives of the study. Regulatory requirements and socioeconomic factors in decision-making are two such aspects that will be critical in the choice of a remedial alternative (or whether to remediate at all). While not addressing such issues in depth, the ARCS Program will identify the major issues that need to be resolved before decisions can be made.3.0 Activities
Many complicated issues need to be addressed in order to accomplish the objectives of this Program. These include:
- Are the sediments contaminated with substances that are harmful to fish or other aquatic life, wildlife, or human health?
- Are the injuries inflicted of such magnitude or quality that remedial action is needed?
- What remedial action alternatives are available, what are their limitations and how effective are they likely to be?
- What are the possible adverse impacts of the remedial action itself?
- What are the costs of taking remedial action?
The three technical Work Groups are responsible for addressing these questions. The general responsibilities of the Work Groups are as follows:
Toxicity/Chemistry Work Group. To assess the current nature and extent of contaminated sediment problems by studying the chemical, physical and biological characteristics of contaminated sediments and their biotic communities; to demonstrate cost-effective assessment techniques at the priority consideration areas that can be used at other Great Lakes Areas of Concern; and to produce three dimensional maps showing the distribution of contaminated sediments in the priority areas.
Risk Assessment/Modeling Work Group. To assess the current and future hazards presented by the contaminated sediments to all biota (aquatic, terrestrial and human) under the "no action" and various remedial alternatives at the priority consideration areas, and to develop a ranking scheme for inter-site comparison.
Engineering/Technology Work Group. To evaluate and test available removal and remedial technologies for contaminated sediments, to select promising technologies for further testing, and to perform field demonstrations of as many of the promising technologies as possible.
Communication/Liaison Work Group. To facilitate the flow of information from the technical Work Groups and the overall ARCS Program to the interested public and to provide feedback from the public to the ARCS Program on needs, expectations and perceived problems.
Activities Integration Committee. The Activities Integration Committee has oversight over the ARCS Program, including the activities of each of the Work Groups. To aid in consistency in Program activities, the Activities Integration Committee is responsible for coordinating Quality Assurance/Quality Control (QA/QC) and data management activities of the ARCS Program. This involves ensuring that proper QA/QC measures are integrated into Work Group activities through the development and peer review of quality assurance and sampling and analysis plans.
More detailed descriptions of each Work Group's objectives and activities are provided in individual Work Group work plans presented in the following chapters.
Some of the priority consideration areas are the sites of intensive work by other programs. Both the Ashtabula River and the Sheboygan River have had numerous investigations performed under the U.S. EPA Superfund Program. Rather than duplicate efforts in these areas, ARCS is following these activities to utilize the information gained, and will focus its resources on factors that are not being fully addressed by Superfund activities. This is felt to be the most cost-effective way to utilize ARCS funds.4.0 Products
Several documents have already been published as a result of ARCS Program activities. A list of publications to date is included in Appendix C. In addition, several final reports and guidance documents will be published. The tentative title of each document and a brief description of its anticipated focus are given below:
Volume I: Executive Summary Document. A comprehensive overview of the ARCS Program, its objectives, activities and outcome.
Volume II: Layman's Guide to Contaminated Sediments. A non-technical overview of the contaminated sediments problem, which would focus on education of the public to enable their effective participation in local sediment-related issues.
Volume III: Contaminated Sediments Assessment Guidance Document. The primary technical document discussing techniques for the assessment of contaminated sediments, as demonstrated in the ARCS Program.
Volume IV: Risk Assessment/Modeling Guidance Document. Describes the modeling and risk/hazard exercises and discusses their usefulness and limitations.
Volume V: Contaminated Sediments Remediation Guidance. The primary technical document discussing techniques for the remediation of contaminated sediments, as demonstrated in the ARCS Program.
Volume VI: Contaminated Sediments Management Document. A management document discussing how to deal with contaminated sediment issues from cleanup of existing contaminated sediments problems to preventing problems from developing in the first place. This document would discuss non-technical issues that need to be addressed in managing sediments, including socioeconomic factors and regulatory requirements. Much of this document will be developed by EPA Headquarters as part of the national contaminated sediment program.
Volumes VII-XI: Each of the five priority consideration areas will be presented as a case study in the implementation of the guidance contained in Volumes III through VI.
In addition to these products, each individual study funded by the ARCS Program will be written up as a technical document.5.0 Quality Assurance/Quality Control
The overall ARCS QA/QC program is detailed in the Quality Assurance Management Plan (QAMP). The QAMP addresses field operations, laboratory and analytical operations, data quality objectives, the laboratory/field audit program, data validation/verification, and data management.
It is U.S. EPA policy that all environmental sampling and testing be done in accordance with a written and approved Quality Assurance Project Plan (QAPP). An approved QAPP is to include the following 14 points:
- project description;
- project organization and responsibilities;
- quality assurance objectives for measurement data in terms of precision, accuracy, completeness, representativeness, and comparability;
- sampling procedures;
- sampling custody;
- calibration procedures and frequency;
- analytical procedures and calibration;
- data reduction, validation, and reporting;
- internal quality control checks;
- performance and system audits;
- preventative maintenance procedures;
- calculation of data quality indicators;
- corrective actions; and
- QA/QC reports to management.
Additionally, each QAPP must have a title page with provisions for approval signatures and a table of contents. Each individual laboratory generating any form of data (i.e., field sampling, field descriptions, analytical results, sediment maps, etc.) for the ARCS Program is required to prepare a QAPP for their individual part of the ARCS Program. Each individual laboratory QAPP will address each of the above 14 items in detail as they relate to the overall ARCS Program. The overall Program will be addressed in the ARCS QAMP. Copies of the approved QAPPs for the ARCS Program will be maintained at the Great Lakes National Program Office in Chicago, Illinois.6.0 Data Management
The ARCS Activities Integration Committee will have overall oversight responsibility for the ARCS data management program. EPA's Office of Marine and Estuarine Protection's ODES database will be the ARCS data repository. Data entry into this repository will be according to the requirements specified by the data management program. The principal investigators will provide their data to EMSL-LV before entry into ODES. This will assure the quality of the data going into the system. Data entry requirements are a component of the participating investigators' QAPPs.
The ARCS Program will be using a Geographic Information System (GIS) for data analysis, output and mapping. The ARCS minimum reporting requirements include the data necessary for use in the system. The data management program is responsible for maintenance of the GIS system, as well as for fulfilling requests from study participants and report authors for particular outputs from the ARCS data base.7.0 Publication Policy
All publications that will result from work funded to support the ARCS Program must comply with the EPA peer and administrative review process. This review process helps ensure that published materials are scientifically valid and reflect EPA policy or that appropriate disclaimers to the contrary are included in the published work. The peer and administrative review process requires that all materials be submitted to the EPA Project Officer for review and comment prior to release to the public. EPA will then return its comments and suggestions for revisions to the principal investigator. If the principal investigator and EPA project officer can agree on the necessary revisions, then the publication will carry a statement to the effect that the document has been approved for publication as an EPA document. If they cannot reach agreement, then any publications must carry a disclaimer stating that the document does not necessarily reflect the views of EPA and no EPA endorsement of the document should be inferred. Articles published in refereed journals are exempt from the EPA review process, since the journal's peer review process will serve the same purpose. In such cases, the principal investigators are required to furnish copies of the article when it is submitted for publication and when it is eventually published. However, the article must still carry a disclaimer stating that it does not have EPA endorsement, since it has not gone through the EPA peer and administrative review process. A detailed explanation of these requirements can be found in 40 CFR Section 30.518.8.0 Summary of Accomplishments
The following is a brief summary of ARCS accomplishments to date. A more complete list of recent accomplishments for each Work Group are listed at the end of Chapters II, III, IV, and V.
- Completed all sampling surveys and laboratory analyses;
- Completed initial drafts of the Human Health Risk Assessment for the Grand Calumet and Saginaw Rivers, and the Aquatic Life Hazard Assessment for the Buffalo River;
- Completed the final draft of the Human Health Risk Assessment for the Buffalo River;
- Completed the pilot-scale treatment demonstrations for the Buffalo River, and performed a partial pilot scale treatment demonstration for the Saginaw River and Bay;
- Published Literature Summaries for the five ARCS Areas of Concern, and several technology reviews;
- Established library repositories at the five Areas of Concern for ARCS Program material and other related information.
In addition, several ARCS Work Group members have presented papers and/or chaired sessions at numerous professional meetings.
The Toxicity/Chemistry Work Group has been responsible for developing and testing sediment assessment methods. This Work Group has been assessing the nature and extent of contaminated sediment problems by studying the chemical, physical and biological characteristics of contaminated sediments and their biotic communities. The Work Group has demonstrated assessment techniques for aquatic life at the priority consideration areas. The information obtained is being used to produce contamination maps of the areas.2.0 Objectives
The primary objectives of the Toxicity/Chemistry Work Group are:
- Assessment Survey Guidance. To develop guidance on the performance of assessment surveys of contaminated sediments through the development of a methodology for such surveys; and
- Demonstration of Assessment Surveys. To demonstrate the assessment survey techniques at the priority consideration areas, and use results and lessons learned in developing guidance.
The tasks needed to accomplish these objectives have been:
- General sampling, characterization, and mapping of sediment deposits;
- Toxicity testing of sediment samples;
- Chemical analysis of sediment;
- Broader spectrum toxicity testing on a selected subset of sediment samples, to compare the relative sensitivities and selectivities of different assays;
- Fish tumor and abnormality surveys; and
- Fish bioaccumulation assays.
In order to properly evaluate the nature and extent of sediment contamination in the priority consideration areas, it is desirable to have information on the physical and spatial characteristics of the sediments and some basic indicator parameters to help select the stations that will be subjected to more intensive testing and characterization.
There are four kinds of sampling stations being used for ARCS sediment testing. Table 1 shows the types of tests done at stations in each category.
For each of the five priority consideration areas, existing information on sediment contamination was obtained and reviewed. At the Saginaw and Buffalo Rivers and Indiana Harbor/Grand Calumet River, a station location grid was prepared to guide sampling and sediment profiling throughout the sites. Numerous sediment core samples (100 to 200 per area) were collected to be tested for a set of "indicator parameters" which can be run relatively inexpensively on large numbers of samples. The core horizons were also visually characterized and photographed. The samples were homogenized and transported to laboratories for biological and chemical analyses as described below.
The core samples were analyzed for the following indicator parameters:
- Sediment Grain Size Fractions,
- Wet Weight,
- Dry Weight,
- Ash Weight,
- Organic Carbon,
- Solvent Extractables,
- Organically-bound Chlorine, Bromine and Iodine,
- Inductively Coupled Plasma (ICP) Analysis of Selected Metals, and
- Microtox Bacterial Luminescence Assay Response.
A first set of seven to ten Master Station surficial sediment samples were collected using a Ponar grab sampler. Highly detailed analyses were performed on these samples (Table 1) for subsequent correlation with the results of the Reconnaissance Stations (described in Section 3.2) where only the indicator parameters are run.
If indicator parameters correlate with the other measurements of contamination and toxicity, use of the indicator parameters will allow the detailed analyses from the few Master Stations to be extrapolated throughout the site, based on correlations between Reconnaissance and Master Station data. Information from these analyses and from profiling data are being used to prepare three-dimensional contamination maps, which will be completed by March, 1992.3.2 Sediment Biological Assessment
Laboratory toxicity testing of the Master Station sediments follows a tiered approach to make efficient use of analytical resources. The results of analyses at one tier are used to select which samples will undergo testing at the next tier. Fewer samples are analyzed in each successive tier since the testing becomes increasingly more time-consuming and costly. Tier I testing focuses on acute toxicity testing, benthic community structure and mutagenicity testing; Tier II focuses on partial life-cycle toxicity and Tier III on full life-cycle toxicity, sediment dilution and bioaccumulation.
Information on benthic community structure obtained in Tier I is combined with physical, chemical and other biological characteristics of sediment quality as part of an overall description of the contamination and its impacts. All Master Station samples undergo Tier I testing, using the following methods on elutriates prepared from the sediment samples:
- Daphnia magna, 48-hr mortality test.
- Microtox (Photobacterium phosphoreum) luminescence test.
- Selenastrum capricornutum, 24-hr carbon-14 uptake test.
Approximately one-half of the Master Station samples undergoing Tier I testing are selected for Tier II testing, which consists of the Hyalella azteca, 7-14 day (whole sediment) growth test. Up to about one-quarter of the samples undergoing Tier I testing also go to Tier III testing, which consists of the Hyalella azteca 28-day (whole sediment) growth test and the fathead minnow (Pimephales promelas) flow-through bioassay (whole sediment). The primary purpose of Tier II and Tier III testing was to evaluate samples not found to be acutely toxic in Tier I. Therefore, most of the samples tested in Tiers II and III exhibited little or no toxicity. Because assessment involved a calibration exercise, a small number of acutely toxic samples were included in Tiers II and III to provide an appropriate range over which to evaluate the tiered testing system. For purposes of comparison, Tier II testing was also performed on Choronomus tenants and Choronomus riparius samples.3.3 Chemical Analysis of Sediment and Fish Samples
Samples of sediments, sediment extracts and fish flesh (from the bioaccumulation assays) collected in the ARCS Program have been subjected to chemical analyses. The analyses include a wide variety of inorganic and organic chemicals important to understanding sediment contamination problems in the priority consideration areas. Chemical parameters include:
- Sediment Organic Carbon,
- Free and Acid Volatile Sulfides,
- Extractable Metals,
- Metals (silver, arsenic, cadmium, chromium, copper, mercury, manganese, nickel, lead, selenium, and zinc) in pore water, elutriates and bulk sediments,
- Organo-metals (methyl mercury and butyl tins),
- Polynuclear aromatic hydrocarbons (naphthalene; 2-methyl naphthalene; fluorene; phenanthrene; anthracene; fluoranthene; pyrene; benz(a)anthracene; chrysene; benzo(b+k)fluoranthene; benzo(a)pyrene; indeno(l,2,3-cd)pyrene);
- Polychlorinated Biphenyls (Aroclors and selected congeners);
- Chlorinated Pesticides (aldrin; alpha-, beta-, gamma-, and deltahexachlorocyclohexane; p,p'-DDE; p,p'-DDD; p,p'-DDT; dieldrin; endosulfan I and II; endosulfan sulfate; endrin; endrin aldehyde; heptaclor; heptaclor epoxide; toxaphene; and methoxychlor);
- Chlorinated Dioxin and Furan congeners; and
- Phthalates (dimethyl; di-n-octyl; bis-2-ethylhexyl; and butyl benzyl).
The bioassays to be performed on samples from selected Master Stations are limited in number, due to constraints of cost, space and personnel. In order to provide guidelines for future contamination surveys, it is necessary to compare the results of the limited suite of bioassays to a larger set of bioassay methods. A cost-effective method of making such a comparison is to perform a more complete suite of bioassays on a reduced number of samples. To implement this, a consortium of university and government laboratories with recognized expertise in numerous other testing methods has been assembled. Sediments from Priority Master Stations at each study area were distributed to these investigators for broader bioassay testing. The resulting information obtained from this effort will be compared with the results of the limited suite of bioassays. Several of these bioassays also yield dose-response information, which will be useful in the Risk Assessment/Modeling Work Group's assessment efforts. This broader-spectrum testing on a limited number of samples also provides a check on the effectiveness of the tiered testing system. Table 2 gives an overview of all bioassay systems evaluated, by organism, exposure route, endpoint type, and duration.3.5 Fish Tumor and External Abnormality Survey
Existing information on the incidence of external abnormalities and internal tumors in fish is sought at each priority consideration area. In addition, surveys to determine the incidence were undertaken in the Buffalo, Ashtabula, Grand Calumet, and Saginaw Rivers. In these cases, fish were collected and targeted for field necropsy and histopathological examination at each area. Brown bullhead (Ictalurus nebulosus) is the primary study species, with the white sucker (Catostomus commersoni) serving as a secondary option. Success in collecting these target species was variable, with none caught from the Grand Calumet River. A final report will be completed in early 1992.3.6 Fish Bioaccumulation Assays
At a very limited number of Master Stations, the Extended Priority Master Stations, a 10-day fathead minnow (Pimephales promelas) bioaccumulation assay was conducted using bulk sediment samples. Analyses of the fish tissue for selected parameters were conducted in September, 1991.4.0 Products
The products of the Toxicity/Chemistry Work Group will consist of the development of technical documents for each discrete work unit (e.g., chemical analysis of sediments, toxicity testing of sediments) and the maps of sediment deposits. In addition, the Toxicity/Chemistry Work Group will have a key role in the development of the Contaminated Sediments Assessment Guidance Document, and Volume III of the final ARCS guidance, which will recommend a much abbreviated, less expensive suite of tests that can be performed to evaluate contaminated sediment. Also, a report will be prepared comparing the chemical and toxicological properties of the sediment with organisms living in these samples. The writing of these documents is being done by a small investigators that were involved in conducting these studies, coordinated by the Work Group Chairperson. GLNPO staff will oversee all phases of the document development.5.0 Recent Accomplishments
- Completed all sampling surveys and laboratory analyses;
- In November, 1990, participated in the 11th annual meeting of the Society for Environmental Toxicology and Chemistry in Arlington, Virginia;
- In June, 1991, presented a series of papers at the 34th Conference on Great Lakes Research in Buffalo, New York;
- In November, 1991, presented seven papers on Work Group findings at the 12th annual meeting of the Society for Environmental Toxicology and Chemistry in Seattle, Washington;
- In November, 1991, a scientific paper explaining the Work Group's approach to developing assessment techniques was published in the Journal of Aquatic Ecosystem Health.
- In November, 1991, a short course on Sediment Assessment and Remediation for environmental managers and engineers included several ARCS investigators as instructors, in Madison, Wisconsin.
The Risk Assessment/Modeling Work Group is responsible for the evaluation of environmental and human health impacts resulting from contaminated sediments, and the development of techniques for assessing the environmental impacts resulting from the implementation of remedial alternatives. A mini-mass balance approach will be taken to provide the predictive capabilities necessary to determine such impact. The assessments will serve to identify and develop techniques and tools for performing sediment-related hazard evaluations. Assessments will consider the difficult task of separating the effects of sediments from those of the water column or other sources. A system for prioritizing sites with contaminated sediments will be developed to provide a comparative framework for assessing multiple sites that are potentially in need of remediation.2.0 Objectives
The primary objectives of the Risk Assessment/Modeling Work Group are:
- Hazard Evaluation: To evaluate exposures to, and impacts resulting from, contact with contaminated sediments and media contaminated by sediment contaminants, incurred by all receptors of concern under the "no action" alternative and other remedial alternatives. This evaluation will draw upon the development and integration of predictive tools to describe future hazards and risks.
- Prioritization System Development: To develop and apply a numerically-based system for use as a decision tool to aid in the prioritization of sites for remedial action;
- Development of Guidance: To develop guidance on the analytical methods for assessing environmental and human health impacts of contaminated sediments, to support decision making.
The tasks needed to accomplish these objectives are:
- Hazard Evaluation
- Mini-mass Balance Approach
- Exposure Model Development
- Field Surveys to Calibrate Models
- Risk/Hazard Assessments
- Aquatic Life
- Mini-mass Balance Approach
- Site Prioritization
- Tasks under section 3.1 address Objective 1; tasks under section 3.2 address Objective 2. Objective 3 will be accomplished by the implementation and interpretation of activities under Objectives 1 and 2, in overall ARCS guidance documents.
As used here, the phrase "hazard evaluation" refers to the overall evaluation of impacts to all receptors of concern resulting from exposure to sediment contaminants, and consists of several discrete assessments. The ultimate purpose of the hazard evaluation is to determine the existing and future health risks and effects (e.g., carcinogenic, reproductive or systemic effects, community structure impacts, etc.) presented to human and environmental receptors (aquatic, avian, mammalian) from direct or indirect contact with sediment contaminants under different remedial options. The hazard evaluation is comprised of 1) an exposure assessment, 2) a human health risk assessment, 3) an aquatic hazard assessment and 4) a wildlife hazard assessment. Strictly speaking, the exposure assessment is an integral part of the human health risk assessment and the aquatic and wildlife hazard assessments, and is not usually separated out as such. However, since the activities involved in performing the exposure assessment are different than those involved in performing a risk or hazard assessment, this work plan makes a distinction between them.
Two levels of evaluation are proposed in this work plan: baseline and comprehensive hazard evaluations (Table 3). Baseline human health hazard evaluations will be performed for all five priority demonstration areas, and will be developed from available site-specific information. The baseline hazard evaluations will describe the hazards to receptors under present site conditions. This baseline assessment will examine all potential pathways that humans may incur risk from exposure to sediments for a given location. Comprehensive hazard evaluations will be performed for the Buffalo River and Saginaw Bay areas. These evaluations will describe the hazards to receptors under different remedial alternatives. These two areas were chosen based upon anticipated impacts from sediments, lack of other on-going activities (such as Superfund remedial activities), and lack of complicating factors (such as complicated ground water/surface water interactions, multiple sources of contaminant inputs, etc.). Information will be obtained through modeling exercises and field studies (described below). A variety of remediation scenarios will be examined as part of the comprehensive evaluation. These will include examining selective removal or capping of hot spots, source control, or dredging of an entire river, among others. Additionally, the comprehensive risk assessment will examine the risk from all components of a remedial process. The Engineering/Technology Work Group will provide hypothetical mass losses of contaminants resulting from each step in a remedial action. The Risk Assessment/Modeling Work Group will then use these mass loadings to develop risk assessments based on losses to the environment.3.1.1 Exposure Assessment
As a component of both the human health risk assessment and the aquatic and wildlife hazard assessments, the exposure assessment strives to describe or predict the receptor's exposure to sediment-related contaminants. The assessment of direct or indirect exposure to sediment contaminants by receptors of concern will vary with the type of receptor considered (human, aquatic, avian, mammalian), the exposure route (ingestion, inhalation, dermal uptake) and the exposure parameters (exposure magnitude, duration and frequency).
Probable human exposure routes which may need to be addressed in this assessment include 1) intake of sediment contaminants through the consumption of fish and avian wildlife into which sediment contaminants have bioaccumulated, 2) intake of sediment contaminants through ingestion of sediments (particularly in children between the ages of two to eight), and 3) dermal uptake of sediment contaminants resulting from recreational use of nearshore contaminated areas. Other exposure routes, such as inhalation of volatile contaminants in sediments or ingestion or inhalation of contaminants from drinking water supplies tainted by sediment contaminants may also be important, and may be considered if important on a site-specific basis.
Exposure assessments for aquatic biota will be evaluated in part by work being performed for the Toxicity/Chemistry Work Group. A suite of bioassays on the toxicological effects of sediment contaminants are planned by the Toxicity/Chemistry Work Group, including those to provide dose-response information. These data, along with existing information, will be the basis for the aquatic biota hazard assessment.
Exposure assessments for piscivorous avian and mammalian wildlife will focus mainly on the uptake of sediment contaminants through the consumption of biota into which sediment contaminants have bioaccumulated. Other routes of exposure may also be of importance, such as intake of contaminated suspended particles in whole water, or direct uptake of sediment contaminants dermally. The feasibility of analyzing these routes will be considered.
The input needed to perform the exposure assessments will be provided by existing information, information obtained from the Toxicity/Chemistry Work Group, through modeling and through the performance of selected field exposure studies.126.96.36.199 Exposure Modeling
The purpose of exposure modeling is to provide a predictive tool to evaluate future exposures (and consequently hazards) if present conditions are maintained ("no action") or if cleanups are undertaken. The development and validation of models will proceed in two phases (Table 4). Phase I will focus on developing modeling tools using existing information.
Phase II will validate the approaches developed in Phase I by obtaining current synoptic information about the area via five to six sampling days on the river. Data will be collected on flows, contaminant loadings and concentrations in the water column of both the particulate and dissolved phases. This work was conducted in September and November, 1990 for the Buffalo River, and May and June, 1991, for the Saginaw River. To support the food chain model, fish species were also collected and are being analyzed. For the Buffalo River, the food chain model will concentrate on carp, while for the Saginaw River, the walleye fishery and other forage fish will be sampled and analyzed.
These data will then be used to calibrate the exposure models. Without calibration, there would be little confidence in the exposure model results.
Due to resource limitations, the Phase II field work to support the mini mass balance modeling studies will only be conducted at two priority consideration areas: Buffalo River and Saginaw Bay. The contaminants to be mass balanced for the Buffalo River include:
The contaminants to be modeled for the Saginaw River are:
The above contaminants were chosen based on fish advisories, concerns cited in the respective Remedial Action Plans, and results obtained from Toxicity Identification Evaluation work. These are also the two areas where comprehensive hazard evaluations will be conducted. The primary objectives of these mass balance modeling studies include the demonstration of available mass balance techniques and how they may be used as an aid in addressing management questions concerning the remediation of contaminated sediments. The mass balance studies are designed to allow estimates of the effects of remedial alternatives, using information provided from other ARCS projects, in order to estimate the response of the AOCs to these alternative remedial actions in terms of toxicity and concentrations of contaminants in the water, sediments and biota. The mass balances being conducted for ARCS are called Level I or preliminary efforts, and some uncertainty is expected. Additional model verification will certainly be necessary in the future
In the mass balance approach, the law of conservation of mass is applied in the evaluation of the sources, transport, and fate of contaminants. The approach requires that the quantities of contaminants entering the system, less quantities stored, transformed, or degraded in the system, must equal the quantities leaving the system. Once a mass balance budget has been established for each pollutant of concern, the approach can be used to provide quantitative estimates of the effects of changes in that budget.
A mass balance model is the means by which the mass balance approach is applied to a natural system. The application of the mass balance method involves the quantification of the sources, transport, and fate of contaminants. The specific components of the exposure modeling study are described below.
- Hydrodynamic Model Application: The complex interaction of flows in the Great Lakes (due to upstream inflows and changes in lake elevation) requires that a hydrodynamic model be applied in order to estimate flows. For the systems of concern in the ARCS modeling studies, the model will be multidimensional in order to provide resolution of lateral as well as possibly vertical gradients in addition to longitudinal gradients in transport characteristics.
- Sediment Transport Model: A model of cohesive sediment transport will be applied in order to predict the interactions between transport, deposition and resuspension processes under various meteorological and hydrological conditions. This model will provide predictions for use in the transport of sorbed contaminants and resuspension of toxic sediments. The model will aid in assessing the no-action alternative by providing estimates of burial rates and the effects of dredging on the system by providing estimates of sediment transport and times required to refill dredged areas. The application of a sediment transport model is of particular importance in these studies due to lack of historical sediment data
- Contaminant Exposure Model: Time variable exposure models will be applied in order to predict the effects of water and sediment transport, as well as the effects of sorption and kinetic processes such as volatilization and degradation, on the concentrations of certain critical contaminants. Modeling studies will be conducted concurrently of the riverine portions of the systems, and affected bays or lakes. The contaminant exposure model will assess the effects of loadings and various remedial alternatives on the system. The models will be applied to estimate load/response/uncertainty relationships, which will aid in addressing the study objectives. The models will also provide information that will be used by the Food Chain Model to estimate the contaminant body burdens in fish species due to varying exposure concentrations in water and sediment.
- Food Chain Model: A model of the food chain will be utilized to estimate the response of varying exposure concentrations on contaminant concentrations in the biota. The model will use data collected as part of the study in order to construct a simple food chain model as well as evaluate certain hypothetical food chains (due to reintroduction of some species) using information obtained from the other studies.
The study will utilize existing models and methods. The model which will be used as a framework for the study is Water Quality Analysis Program, WASP4 (Ambrose et al. 1988). This model will be used to integrate predictions from other models (e.g. hydrodynamic and sediment transport) in order to estimate contaminant concentrations in the water sediment and biota. The WASP4 model provides a consistent modeling framework for eutrophication, toxics transformation and transport, bioaccumulation, and food chain effects. It is maintained and distributed by the Center for Exposure Assessment Modeling, located at EPA's Environmental Research Laboratory in Athens, Georgia, and has been widely distributed around the world. It is presently the framework used for modeling studies in Green Bay, Lake Michigan, as well as studies on Lake Ontario and elsewhere on the Great Lakes.188.8.131.52 Synoptic Surveys
Field sampling programs were designed to provide information required for the application of mass balance models. Synoptic surveys were performed for six sampling days for the lower Buffalo and Saginaw Rivers. The sampling stations were selected to allow estimates of pollutant influxes to, and effluxes from, the AOCs. Samples were integrated over the width of the system. The data collected during the synoptic surveys included flows, loading and concentration data for solids and chemicals in both water and suspended solids. Samples for selected conventional parameters were collected at a greater frequency in order to aid in calibration of the hydrodynamic and sediment transport model, and in order to aid in estimating yearly loadings. Data on sediment contamination is being collected as part of studies of other ARCS Work Groups. The types of data to be obtained are briefly described below.
- Hydrodynamic Data: Data for the calibration of the hydrodynamic model includes historical data as well as data collected as part of the field studies. Historical data are available on flows, water surface elevations at the mouth of the Buffalo and Saginaw Rivers, meteorological data, and concentrations of some conventional constituents such as temperature, conductivity, etc. The above data were also obtained concurrently with field studies. In addition, water surface elevation data, velocity and discharge measurements, and wind velocity and direction data were obtained.
- Sediment Transport Data: Data for the calibration of the sediment transport model also relies on historical data, such as U.S. ACE dredging records. Information on sediment characteristics (e.g. grain size, water content, etc.) was determined during the sediment surveys. Also, bathymetry surveys were conducted to estimate changes in the system's morphometry. Data on suspended solids were collected concurrently with the river sampling, and suspended solids data were collected either during high flow events (Buffalo River ) or hourly during certain periods (Saginaw) in order to support the sediment transport model. Finally, "shaker" studies will be conducted to estimate the resuspension characteristics of the sediments.
- Contaminant Exposure Data: Ambient water, sediment, loading, and food chain data for the calibration of the exposure model will use, whenever possible, historical data. In addition, surveys were conducted to identify spatial variability in the system during varying flow conditions in 1990. Further studies will be conducted to identify pollutant loadings and ambient pollutant concentrations in water and sediments, and biota.
- Pollutant Loadings: Pollutant loadings are being estimated and/or measured from point and non-point sources. Historical data are being assessed to estimate loadings from point sources as well as measurements acquired concurrently with the ambient water quality studies. Loadings from Combined Sewer Overflows (CSOs) are being estimated based on a limited field sampling program (24 samples at 10 CSOs) and storm water modeling in the Buffalo River study (CSOs were not identified as significant sources and were not sampled in Saginaw). Loadings for contaminants and suspended solids from upstream tributaries are based on 6 daily averaged measurements taken during the fall of 1990. Historical contaminant, suspended solids and flow data, as well as data from the suspended solids survey, are being used to extrapolate these measurements to annual loading rates. An analysis of the uncertainty of these estimates is also being performed.
- Ambient Water Concentrations: Ambient data for particulate and dissolved contaminants as well as conventional parameters were obtained over six sampling days during the fall of 1990.
- Sediment Data: Data for sediment concentrations were collected as part of separate sampling studies in 1990.
- Food Chain Data: Data have been collected for carp in the Buffalo River and their stomach contents analyzed in order to establish a relationship between carp contaminant concentrations and their benthic forage. Carp were selected for analyses for two reasons. First, there are presently advisories in effect for consumption of carp in the Buffalo River. Second, the available resources limit the possibility of collection data to support an evaluation of fish species with a more complex food chain. Carp samples were collected and divided into three age classes for analysis. Sampling in the Saginaw River concentrated on walleye and its food chain due to the importance of the walleye fishery in this area.
The final phase of this approach will be to verify and calibrate the models in Phase I using the site-specific data collected in Phase II.3.1.2 Risk and Hazard Assessments
The activities involved in the preparation of the individual Risk and Hazard Assessments vary depending upon the area evaluated, the receptors and the endpoints considered. It is primarily a paper exercise, combining information on exposure to, and toxicity of, sediment contaminants. The experience gained from performing these assessments at the five ARCS AOCs will provide more refined tools to be used at the other AOCs than were previously available. The Baseline Assessments use existing data, while the Comprehensive Assessments use the results obtained from the exposure modeling work to predict future risk.184.108.40.206 Human Health Risk Assessment
Cancer risks and non-cancer hazards potentially incurred resulting from direct and indirect exposure to sediment contaminants, will be considered. Risks and hazards will be calculated using methods recommended by the U.S. EPA Risk Assessment Guidelines of 1986 and other generally recognized risk assessment procedures. Uncertainties in the risk assessment will be stated, as will the assumptions, and discussion on the overall meaning of the risk assessment will be developed. Toxicological information required to calculate risks or hazards may not be available for all chemicals found in the demonstration areas. Therefore, the baseline risk assessment will identify information which is required for the evaluation but not available, and such needs will be recommended to the Activities Integration Committee for resolution. As part of the comprehensive evaluations planned for the Buffalo River and Saginaw Bay, target sediment concentrations (i.e., chemical concentrations below that associated with unacceptable risks and hazards) will be calculated for chemicals identified as responsible for the majority of the risk or hazard.
One of the more potentially important impacts of some chlorinated organic compounds, such as PCBs, is their potential for adverse developmental effects upon infants and children. Recent epidemiological evidence exists that suggests developmental effects have occurred in young children whose mothers were heavy consumers of Great Lakes fish. Given the relationship between sediment and fish contamination, this toxicological endpoint should be assessed in the ARCS program. However, this endpoint is not easily assessed in a quantitative fashion using the existing risk assessment methodology commonly employed by the U.S. EPA. This arises from the hypothesis that the contaminants, to which the infant or child is exposed through placental transfer and breast-feeding, is a result of the mother's body burden of the chemical. This maternal body burden is the result of her lifetime of contaminant intake, not only that occurring during pregnancy. Assessment would require complex pharmacokinetic modeling, an approach which is not well developed in the environmental assessment field.
Given the difficulties which exist in quantifying this hazard, it is beyond the scope of the ARCS program to address this issue in any great depth. However, ARCS would be remiss if it did not address the issue at all. Therefore, the Risk Assessment/Modeling Work Group is pursuing the option to develop an issue or problem identification paper on the subject. It is envisioned that the paper would summarize the existing epidemiological information, discuss the relationship between sediments, fish consumption, human body burden, and human-to-human chemical transfer, and discuss the inadequacies of present assessment techniques to describe the problem.220.127.116.11 Aquatic Life Hazard Assessment
Aquatic life hazard assessment is an emerging discipline which differs fundamentally from assessments of human health effects. Current approaches for assessing the hazards to aquatic life (such as endangerment of health and viability of populations and communities) focus on existing ecological toxicity, as determined by field or laboratory studies. This type of information will be available from the Toxicity/Chemistry Work Group. Other types of descriptors of toxicity, based on chemical, physical and biological factors, such as the Equilibrium Partitioning Approach to calculating numerical sediment criteria from water quality criteria, the Apparent Effects Threshold and the Sediment Quality Triad, will also be part of the Toxicity/Chemistry Work Group output, and will be used to express and estimate future exposures and effects under the various remedial alternatives. To predict impacts on aquatic life under various remedial alternatives, toxicological information describing dose-response relationships will be used. A baseline aquatic life hazard evaluation is being performed for the Buffalo River. This approach can be made available for application to other sites.18.104.22.168 Wildlife Hazard Assessment
Hazards to piscivorous avian and mammalian species are of primary concern for areas within the Great Lakes System. Adverse health effects, such as reproductive impairment and structural deformities, resulting from intake of contaminants in food, have been documented. Description of such effects are generally an outcome of field studies; prospective hazard assessments are not commonly performed. However, since the primary route of contaminant intake is through the consumption of contaminated food (fish), a rough prospective hazard evaluation can be performed in a manner similar to human food chain concerns. As above, the baseline hazard assessment is being based on existing information on impacts upon wildlife in the area, with an emphasis on the degree of hazard attributable to contaminated sediment, as compared with other "sources" of contaminants to wildlife. For the comprehensive assessment, future impacts will be based upon modeled exposures. Limitations of performing such an assessment will be discussed. Baseline and comprehensive wildlife hazard evaluations will be performed at two of the priority consideration areas (Buffalo River and Saginaw Bay). This approach can be made available for application at other sites where wildlife impacts from contaminated sediment are of concern.3.2 Site Prioritization for Remedial Action and Development of Decision Support Tools
A numerically-based ranking system which synthesizes assessment variables and produces objective priorities will be designed to allow remedial priorities to be set for each of the Great Lakes Areas of Concern. Development of numerically-based ranking will provide a method for integrating hazard and risk assessments within and between individual Areas of Concern. The result will be a prioritization procedure that can be used in a comprehensive strategy for the management of contaminated sediments.
The following are tasks anticipated for this activity to provide site ranking and integration of information about individual sites or areas of concern:
- Investigate methods of ranking and decision support analysis to determine what other approaches should be incorporated for the ARCS program;
- Develop a ranking method to integrate measures of hazard, risk and cost;
- Develop a method of ranking sites which can be applied to the Great Lakes Region, by State and Provincial jurisdictions, or smaller sub-regions (i.e., individual lake watersheds);
- Calibrate test the ranking procedure and integration procedure on the five priority consideration areas being investigated during the ARCS Program.
This work will be closely coordinated with the data collection and assessment activities of the Toxicity/Chemistry Work Group.4.0 Products
The products of the Risk Assessment/Modeling Work Group will consist of technical documents for each discrete work unit (e.g., the baseline and comprehensive hazard evaluations). In addition, much of the work performed for this Work Group will be an integral part of the Risk Assessment/Modeling Guidance Document and the Contaminated Sediments Remediation Guidance Document, discussed in Part I, and members will have direct input into the development of these guidance documents.5.0 Recent Accomplishments
- In support of mini-mass balance work:
- completed water column, fish and CSO sampling on the Buffalo River.
- completed water column and fish sampling on lower five miles of Saginaw River.
- began chemical analyses of Buffalo and Saginaw River water, sediment and fish samples.
- Completed initial application and testing of hydrodynamic models on Buffalo and Saginaw Rivers.
- Completed initial set-up and screening calculations for contaminant transport.
- Completed initial linkage and testing of hydrodynamic and contaminant models.
- Completed initial linkage and testing of sediment transport and contaminant models.
- In support of sediment transport and resuspension effect on the Buffalo and Saginaw Rivers.
- sampled suspended solids on a regular basis focusing on runoff events.
- conducted soundings of selected transects to ascertain changes in bottom profiles over time.
- conducted field shaker tests to determine resuspension potential of contaminated sediments.
- Completed initial drafts of Human Health Baseline Risk Assessment for Grand Calumet River and Saginaw Rivers.
- Completed final draft of the Human Health Baseline Risk Assessment for the Buffalo River.
- Completed first draft of Aquatic Life Hazard Assessment for the Buffalo River.
The primary responsibilities of the Engineering/Technology Work Group are to evaluate and test available remedial technologies for contaminated sediments, to select promising new technologies for further testing, to demonstrate alternatives at priority consideration areas, and to estimate contaminant losses during remediation. The Engineering/Technology Work Group will seek technologies that are available, implementable, and economically feasible. Both removal and in situ alternatives will be considered.2.0 Objectives
The primary objectives of the Engineering/Technology Work Group are:
- Evaluation of existing technologies: To evaluate the effectiveness, technical feasibility and cost of existing technologies to remediate contaminated sediments and estimate contaminant losses during remediation;
- Demonstration of effectiveness: To demonstrate the effectiveness of sediment remedial technologies through the performance of bench-scale tests, and pilot scale demonstration projects at selected priority consideration areas;
- Options Development: To develop options for the remediation of contaminated sediments at the five priority consideration areas; and
- Development of Remediation Guidance: To develop guidance on the selection and implementation of contaminated sediment remedial alternatives.
The tasks needed to accomplish the Work Group objectives have been:
- Perform a review of technical literature;
- Evaluate the applicability of technologies for bench-scale studies;
- Estimate contaminant losses during remediation;
- Collect sediments for bench-scale testing;
- Sediment storage and analysis;
- Convene a workshop on bioremediation technologies;
- Evaluate solidification/stabilization technologies;
- Tasks currently being performed include:
- Evaluate treatment technologies for inorganic contaminants;
- Conduct bench-scale tests of selected treatment technologies;
- Conduct pilot-scale demonstrations; and
- Develop options for priority consideration areas.
Existing literature on contaminated sediment treatment technologies has been reviewed for the ARCS Program by the U.S. Army Corps of Engineers' Waterways Experiment Station (WES), focusing on the updating of present knowledge on the selection and use of technologies for removal and transport of contaminated sediments, placement/disposal of material at disposal sites, treatment technologies, as well as in situ techniques. The final report is completed (Averett et al., see Appendix 3). Previous technology assessments and field demonstration studies conducted by the U.S. EPA, U.S. Army Corps of Engineers and others were reviewed for applicability.3.2 Evaluate the Applicability of Technologies for Bench-Scale Studies
The applicability of treatment technologies to priority consideration areas were evaluated based upon the nature and degree of contamination at the site. Treatment technologies identified in Task 1 were matched with the contaminants present and the level of contamination and volume of sediments to which each technology can be applied. Each technology was evaluated based on costs, effectiveness, volume of material to be handled, level of existing contamination and levels of cleanup required. Table 4 shows treatment technologies selected for each Priority Consideration area to be demonstrated by the ARCS Program.3.3 Estimate Contaminant Losses During Remediation
Contaminant inputs which may occur to the environment during and after implementation of the remedial alternative will be assessed. Models available to calculate losses during dredging, volatilization losses, leaching losses, run-off and effluent concentrations will be reviewed. Models will be selected to calculate the annual losses to the environment resulting from each treatment technology evaluated. These contaminant loads to the environment will be supplied to the Risk Assessment/Modeling Work Group who will assess the human and environmental health impacts associated with each of the remedial alternatives. These tasks will be accomplished by WES and USEPA's Environmental Research Laboratory in Athens, Georgia (ERL/Athens). Coordination between WES and ERL/Athens is underway. The schedule is as follows:
Scheduled Actual Start Completion Completion Date Date Date A) Phase I, Briefing to 6/90 9/90 9/90 Work Group B) Phase II, Draft Report 1/91 9/91 10/91 C) Phase III, Draft Report 8/91 2/92 D) Publish Final Report 2/92 7/923.4 Collect Sediments for Bench-Scale Testing
The bench-scale tests (discussed below) require sediments for testing from the five priority consideration areas. The same or similar sediment samples will be used to evaluate and compare similar demonstration projects. Therefore, it was necessary to collect, characterize, and preserve large-volume sediment samples from each of the areas. Sediment samples consist of homogenized, moist composites of samples from a contaminated region within the area. Sediments were collected for all five (5) areas for bench-scale studies. Sediments were collected by bucket at the following sites: 1) off Buffalo Color Corporation in the Buffalo River (100 gallons), 2) from three (3) sites in the Saginaw River (100 gallons), 3) from a potential hot spot near General Motors in the Saginaw River (50 gallons), and 4) from one location in the Indiana Harbor Canal (100 gallons). In the Ashtabula River, 100 gallons were collected by boring at various locations and depths. Two gallons were collected from Sheboygan. Additional samples will be collected for the pilot demonstration projects.3.5 Sediment Storage and Analysis
The sediment samples were homogenized and split into representative subsamples (wet). The wet subsamples were provided in appropriate volumes for use by the various investigators. The procedure that will be used has been previously applied to sediments from Lake Ontario and the Fox River/Green Bay, and has been validated for organic carbon and organochlorine contaminant homogeneity. Wet samples are stored in a cold-room at 4deg.C.
The basic characterization of the sediment includes the following parameters:
- total inorganic carbon;
- total organic carbon;
- particle size analysis (wet sieve analysis from 710 to 63 m, detailed analysis below 63 m);
- density of dry material; total sulfur content;
- acid volatile sulfides;
- oil and grease;
- total PCBs;
- PAHs (at least 10 compounds);
- metals (ICAP); and
Particular promising technologies identified in Task 3 will be evaluated in bench-scale tests using sediments from the priority consideration areas. As used here, bench-scale tests mean ones that are done on a few grams to kilograms of sediment. The selection of which technology to use on which priority consideration area depended upon matching-up the characteristics of each (i.e., a PCB treatment method will be matched with a location having PCB contamination problems).
Bench-scale testing will provide preliminary feasibility data and design data for pilotscale demonstrations of selected technologies. As used here, pilot-scale tests are those that involve up to several cubic meters of sediments. Treatment technologies have been evaluated in bench-scale tests and the sediments tested are shown in Table 4.
There is a contract for bench-scale testing of sediment treatment technologies with SAIC Corporation. A kickoff meeting for the work plan was held in Cincinnati in August, 1990. Eight bench-scale tests will be completed, and the final report will be ready in March, 1992. Depending upon results, some of these bench-scale tests may be and several new tests will be initiated.
Sheboygan River sediment was tested by USEPA, Cincinnati Laboratory, using the Base Catalyzed Decomposition (BCD) process. All Aroclor congeners were reduced to below 2 ppm. Samples from the Ashtabula River and the Grand Calumet Harbor were also sent to the laboratory.
Sheboygan River sediment was sent to ECOLogic for testing with their hazardous waste destructor. The ECO Logic process requires heat (about 800 C), but the breakup of contaminants is achieved by the injected reducing agent, free hydrogen. A destruction removal efficiency of greater than 99% was achieved, in bench scale testing.3.7 Evaluate Treatment Technologies for Inorganic Contaminants
This task will examine the treatment options that are available for inorganic contaminants including metals. Treatment options will be evaluated using sediment samples from all five of the priority consideration areas. Techniques used for extraction and recovery of metals from ores and wastes will be evaluated on contaminated sediments. These include physical separation processes using gravity and magnetic properties, and flotation processes.
A series of interagency agreements have been entered into with the U.S. Bureau of Mines, with the U.S. work to be carried out at their Salt Lake City Research Facility. Initial characterization tests were performed on sediments from the Buffalo, Saginaw, and Grand Calumet Rivers. A QAPP has been prepared and approved. Testing of the sediments was completed in March, 1991, and a final report is due in December, 1991. Additional work to be conducted in 1992 will be described in a second report, to be completed in 1993.3.8 Workshop on Bioremediation
A workshop was held July 17-19, 1990, in Manitowoc, Wisconsin. More than 60 scientists from state and federal agencies, academia, and the private sector from the United States, Canada, and the Netherlands, participated.
During the workshop, presentations were made describing site characteristics of the five ARCS priority U.S. Areas of Concern and for Hamilton Harbour, Ontario. Major contaminants within these and other areas include polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and various heavy metal species.
The remainder of the workshop was devoted to discussing related laboratory and field studies and the applicability of biological remediation processes for these contaminants. Workshop presentations and discussions underscored the fact that biological remediation technologies for these classes of compounds are in rapid development, and in some situations may warrant evaluation as a component(s) in remediation strategies, especially when confined disposal options are leading alternatives. For PCB mixtures (Aroclors), anaerobic reductive dechlorination, shown by several investigators to occur in both historically contaminated sediments at various sites and in laboratory spiked sediments, results in the same molar concentration of PCBs with fewer average chlorines per molecule. While this process reduces toxicity alone, further aerobic treatment, believed to be partially a cometabolic process, may result in complete mineralization. For PAH compounds, aerobic microbial and fungal decomposition is fairly well documented, whereas biological treatment of sediments for the remediation of metal species has been considered only recently. In related areas, however, microbially mediated precipitation and/or dissolution reactions of metal species have been effectively utilized. Proceedings from the workshop are available from NTIS.3.9 Evaluation of Chemical Solidification/Stabilization Technologies
Besides removal and disposal, chemical solidification/stabilization (CSS) techniques are probably the most proven techniques for remediation of contaminated sediments. CSS techniques were investigated for the Buffalo River. The scope of the study involves laboratory preparation of CSS samples using Buffalo River sediment and one of the following binders/additives: Portland Cement, lime/fly ash, kiln dust, and Portland cement with powdered activated carbon. A range of binder-to-sediment ratios was screened and an optimum ratio was selected for detailed evaluation. Effectiveness was measured by comparing leaching results, unconfined compressive strength, and durability under wet/dry and freeze/thaw cycles. A final report is available.3.10 Pilot-Scale Demonstration Projects
Pilot-scale demonstrations began in FY 1991 and will continue through FY 1992. The scale of the pilot demonstrations will be several hundred cubic yards of sediment. Full-scale demonstrations would address in the range of 5,000 to 10,000 cubic yards of sediment. Pilotscale demonstrations will only demonstrate the unit process (e.g., extraction). They will not include the full treatment train (e.g., dredging, storage, sorting, dewatering, extraction, destruction of extract, solidification, final disposal) that a full-scale demonstration would include. Pilot-scale demonstrations can be performed either on-site or at an off-site location, but will be performed on-site at all five ARCS priority locations.3.11 Development of Options for Priority Consideration Areas
Based upon the information gained in the earlier tasks, concept plans for sediment remedial options will be developed for each priority consideration area. The costs of applying the selected options will be calculated. In addition, estimates will be made on the losses of contaminants that might result from applying the remedial actions. The Risk Assessment/Modeling Work Group will use this and other information to evaluate the hazards associated with each remedial option. These plans will also serve to identify data gaps that need to be filled in order to complete the process of selecting the best remedial options for each priority consideration area. Because it would be premature to select the single best remedial option for each area, the concept plans will present three different remediation scenarios for each priority consideration area. These plans will provide very useful information to the State and local groups responsible for the development of sediment remediation plans. Concept plans will be prepared in 1993, after demonstration projects have been completed.3.12 Summaries of Treatment Technologies
The following are short descriptions of each of the technologies listed in Table 5:
- Solidification/Stabilization: The addition of binding materials to produce a more stable solid material that is more resistant to the leaching of contaminants. Typical binding material used include portland cement, fly ash, kiln dust, blast furnace slag, and proprietary additives.
- Inorganic Treatment/Recovery: The physical or chemical separation of sediments into different fractions that may be more or less contaminated. Since sediment contaminants usually associate themselves with fine-grained particles like silts and clays, their separation from the bulk of the sediments could significantly reduce the volume of material requiring advanced treatment.
- Bioremediation: The use of microorganisms such as bacteria to reduce the toxicity of sediment contaminants by degrading them through biological action. Used in the treatment of waste waters and contaminated soils.
- Based Catalyzed Decomposition (BCD) (Process formerly called KPEG Nucleophilic Substitution): A chemical process that reduces the toxicity of chlorinated hydrocarbons (such as PCBs) by removing chlorine atoms and replacing them with alkali metals (such as potassium).
- Basic Extraction Sludge Technology (BEST) Extraction Process: Separates contaminated sediments into three fractions: a solid fraction that contains the inorganic contaminants (such as heavy metals); an oil fraction that contains the organic contaminants (such as PCBs); and a water fraction that may contain residual amounts of the original sediment contaminants. By itself, BEST does not destroy any contaminants, but may significantly reduce the volume of material requiring advanced treatment.
- Low Temperature Thermal Stripping: Removes volatile organic contaminants (such as polynuclear aromatic hydrocarbons, or PAHs) by heating the sediments to temperatures lower than those used in the destructive incineration process. Not intended to permanently destroy contaminants, but may result in a sediment that can be more easily disposed of.
- Wet Air Oxidation: Organic contaminants are destroyed by exposing them to elevated temperatures and pressures. This process was developed over 30 years ago and has been successfully used to treat municipal sewage sludge.
- Low Energy Extraction: Separates contaminated sediments into fractions as described for the BEST process. Uses a combination of solvents to remove PCBs and other organic contaminants from the sediment.
- Eco-Logic Destruction Process: A thermochemical process that uses high temperatures and hydrogen gas to destroy organic contaminants.
- In-Situ Stabilization: The covering or armoring of sediment deposits with geotextiles, plastic liners, or graded stone. Prevents the disturbance and resuspension of contaminated sediments, which could lead to a release of sediment contaminants back into the water column.
- Acetone Extraction (Rem-Tech): Acetone is used as a solvent to extract PCBs from contaminated sediments.
- Aqueous Surfactant Extraction: Similar to the Low Energy Extraction process. Instead of applying acetone, however, this process uses aqueous surfactant to remove PCBs. Ultrasonics may be employed to improve extraction efficiencies.
- Sediment Dewatering Methods: Techniques to remove the water from contaminated sediments, such as air drying, consolidation, and filter presses. May be necessary prior to the application of a treatment technology that works inefficiently in the presence of water.
Description: ARCS will conduct a pilot demonstration of a low temperature thermal stripping process, to extract organic contaminants from the sediments. This is a thermal desorption process that removes semivolatile organic contaminants (such as polynuclear aromatic hydrocarbons, or PAHs) by heating the sediments to temperatures lower than those used in the destructive incineration process.
Volume: Approximately 10 - 15 cubic yards
Date: Fall 1992
Description: ARCS conducted a pilot demonstration of a low temperature thermal extraction process, to extract organic contaminants from the sediment. This process, like low temperature thermal stripping process, is a thermal desorption process that removes semivolatile organic contaminants (such as polynuclear aromatic hydrocarbons, or PAHs) from sediments. Organic contaminants are removed from sediments by heating sediments to temperatures high enough to volatilize the contaminants, but lower than those used in the destructive incineration process. ReTec technology was demonstrated. A report summarizing this project will be prepared.
Volume: Approximately 12 cubic yards
Location: Corps of Engineers--Confined Disposal Facility in Buffalo
Date: October, 1991
GRAND CALUMET RIVER/INDIANA HARBOR CANAL
Description: ARCS will conduct a pilot demonstration applying solvent extraction to contaminated sediments. This process involves exposing the sediment to a chemical solvent that will separate the organic contaminants from the sediment.
Volume: Approximately 1 cubic yard
Location: USX Gary Works Plant
Date: April, 1992
Description: ARCS will conduct a particle size separation pilot demonstration, using hydrocyclone or another physical separation technology. This technology is expected to result in a reduction in volume of the heavily contaminated sediment fraction. This heavily contaminated sediment fraction will then undergo further treatment.
Volume: Approximately 300 cubic yards
Location: Corps of Engineers Confined Disposal Facility in the Saginaw River
Date: October, 1991, and spring, 1992
Description: ARCS will provide technical support and assistance to the Superfund efforts currently underway at Sheboygan, Wisconsin, through USEPA's Environmental Research Laboratory in Athens, Georgia. Technical support will involve a scientific review of the Sheboygan bioremediation pilot project already underway, including recommendations for enhancing the experimental design of the project, and the sampling required to achieve a statistically supportable documentation of its effectiveness.
Location: Confined Treatment Facility
Date: 19924.0 Products
The products of the Engineering/Technology Work Group will consist of the development of technical documents for each discrete work unit (e.g., bench-scale testing, pilot-scale testing). One key product of this Work Group is a matrix of monetary costs versus contaminant losses from the technologies tested. This information will be provided to the Risk Assessment/Modeling Work Group for use in evaluating the impacts of alternative remedial options. Table 5 summarizes the match-up of technologies and locations planned for the ARCS demonstrations. The table also includes technology demonstrations that have been or are being done under other programs, including the U.S. Army Corps of Engineers, Superfund PRPs and Canada. The Engineering/Technology Work Group will make use of the results of these other demonstrations along with the ones being done specifically for ARCS.
In addition, much of the work performed for this Work Group will be an integral part of the Contaminated Sediments Remediation Guidance Document, discussed in Part I, and members will have direct input into the development of this guidance document.5.0 Recent Accomplishments
- Published the proceedings of a workshop on Biological Remediation of Contaminated Sediments.
- Published the report, "Review of Removal, Containment, and Treatment Technologies for Remediation of Contaminated Sediment in the Great Lakes".
- Prepared the final report, "An Evaluation of Solidification/Stabilization Technology for Buffalo River Sediment".
- Prepared work plans for pilot demonstration projects at Buffalo, Saginaw, and Grand Calumet.
- Prepared a work plan for Evaluation of Contaminant Losses from Components of Remediation Alternatives for Contaminated Sediment, and started the next phase of work.
- Performed or initiated work for the following three pilot demonstrations:
- Buffalo River--(conducted in fall, 1991) thermal desorption of organic contaminants and solidification/stabilization of the residue. The location is the Buffalo Confined Disposal Facility Number Four.
- Grand Calumet River--chemical extraction of organic contaminants at the USX Gary Works, in conjunction with the USEPA Superfund SITE Program.
- Saginaw River and Bay--(begun in fall, 1991) a particle size separation pilot demonstration using hydrocyclone technology. The heavily contaminated fraction will be subjected to a solvent extraction process to remove organize contaminates. A biological remediation will also be conducted on the heavily contaminated fraction. The location is the Saginaw Confined Facility.
- Two ET Work Group members made presentations at a Canadian Workshop on Dredging and Remediation of Contaminated Sediments.
- Bench scale testing was completed by SAIC.
The Communication/Liaison Work Group was established to disseminate up-to-date information regarding the ARCS Program and related activities to elected officials, government agencies, and the interested public. The group also provides feedback from those interested parties to the technical work groups and other ARCS committees.
Ongoing communication between the technical work groups and the Communication/Liaison Work Group regarding research and field work is critical to the ongoing success of this work group. In part, this will be accomplished through weekly conference calls with the AIC, and work group members' attendance at other work group meetings.
Timely notice of upcoming events to our work group members and interested citizens is essential in ensuring our goal of full public scrutiny of ARCS.
The work group's communication efforts will continue to stress that ARCS is not a clean-up program, but is designed to assess the contaminated sediments problem, to identify practical remedial options, and to test new technologies on bench and pilot scales.2.0 Objectives
The primary objectives of the Communication/Liaison Work Group are:
- Track Program Operations in order to keep Work Group members informed of the overall status of the ARCS Program and ongoing efforts of each technical work group.
- Disseminate Information about the program regularly to the public, other organizations and agencies, and elected officials in the U.S., as well as to Canadian Federal and Provincial agencies involved in contaminated sediment issues.
- Solicit Feedback from the public and elected officials on the progress and scope of the ARCS Program, and communicate the substance of this feedback to the other work group chairs, the ARCS Management Advisory Committee and GLNPO Management.
- Encourage Public Participation. During all phases of the project, the Work Group seeks to encourage and maintain strong public interest in the ARCS Program through public meetings, news releases, informal information exchange, and other activities.
The tasks needed to accomplish these objectives are the following:
- Continual work group interaction;
- Preparation and dissemination of general and site-specific information materials on the ARCS Program and on contaminated sediments in general;
- Mailing list compilation and maintenance;
- Solicitation of public input through news updates, press releases, questionnaires, public meetings and informal dialogue;
- Development and maintenance of library repositories for contaminated sediment and ARCS Program materials in the five priority areas;
- On-site coordination of public meetings and press briefings;
- Slide-show preparation and dissemination; and
- Guidelines for public participation and community outreach plans when appropriate.
Frequent contact with members of other work groups is maintained, and interviews are scheduled as appropriate to obtain information on planned or ongoing work. The Communication/Liaison Work Group will receive summaries of other work group meetings and work plan revisions on a regular basis.3.2 Preparation of Information Materials
The Communication/Liaison Work Group prepares press releases, fact sheets and other written materials for dissemination to interested Federal and State agencies, elected officials, and the public at regular intervals.
Periodic "ARCS Updates" will continue to be produced and distributed. They will provide information not only on ARCS Program activities, but also on cooperative efforts and information sharing with other projects (such as EPA's Superfund Program, Environment Canada's contaminated sediment research, etc.) and on more general topics such as current scientific research that relates contaminated sediments to ecological impacts on the Great Lakes.
Updates on activities specific to the priority consideration areas will be included in the Fact Sheets or produced and disseminated separately as needed. Press releases will be coordinated and issued by the Communication/Liaison Work Group member representing U.S. EPA's Office of Public Affairs in cooperation with the Communication/Liaison Work Group member in the U.S. Army Corps of Engineers' North Central Division, where appropriate.3.3 Mailing List Compilation
A mailing list has been compiled and will continue to be maintained and updated regularly to disseminate information gathered in the tasks above to the appropriate interested parties.3.4 Soliciting Public Input
Ongoing and regular feedback will continue to be sought from environmental groups, elected officials and the general public, and will be communicated to the other work groups, GLNPO staff, and the Management Advisory Committee.3.5 Development and Maintenance of Library Repositories
Repositories have been established and are being maintained for all of the five priority areas. For a listing of all ARCS library repositories, see Appendix B.3.6 On-Site Coordination and Public Meetings
Representatives from the Communication/Liaison Work Group will continue to travel to the priority consideration sites to inform the public and media about the ARCS Program, ongoing field work, research activities and results. Meetings with interested public have already been held at four of the five sites (Saginaw, Buffalo, Indiana Harbor, and Ashtabula. Second meetings will be held at these four sites in fiscal 1992 along with at least one meeting in Sheboygan. Efforts will be made to conduct additional meetings with RAP Public Advisory Committees in various Great Lakes locations where interest is expressed.3.7 Slide Show Preparation
A slide show has been developed and is being disseminated to describe the contaminated sediment issue in general and the ARCS program in particular. A minimum of 10 presentations will be made by Work Group members in fiscal 1992.3.8 Video Documentation
Video footage on demonstration projects and related field activities will be produced to document MCS activities. Consideration will be given to preparing an overall sediment remediation documentary.4.0 Products
The products of the Communication/Liaison Work Group will consist of the fact sheets, press releases, slide show, video footage and other forms of communication discussed above. Much of the work performed by this Work Group will be an integral part of the Contaminated Sediments Management Documents, discussed in Part 1. Members will have an opportunity for direct input into the development of these guidance documents.
5.0 Recent Accomplishments
- In Fiscal Year 1991, the Communication/Liaison Work Group produced two "ARCS Updates", and several site-specific fact sheets and news releases. A slide show was developed and disseminated, and video footage was taken.
- Members of the work group scheduled and coordinated meetings with Remedial Action Plan Public Advisory Committees in Ashtabula, Ohio, and the Grand Calumet River/Indiana Harbor Canal, as well as speaking to approximately 30 interested civic and environmental groups around the Great Lakes basin. Work Group members also participated in professional discussions of contaminated sediment assessment and remediation Action Plan forum of the International Joint Commission in Traverse City, Michigan, in September 1991.
- The Work Group participated in a press conference and public information dissemination regarding a pilot demonstrations in Saginaw Bay, Michigan, and the Buffalo River, New York.
- The Work Group enlarged its mailing list to approximately 1,000 people. It also fielded requests for information and collected feedback on the program from the public for dissemination to EPA managers.
- Library repositories for ARCS material and other information on contaminated sediment have been established in the five priority areas and materials have been distributed to them.