United States Environmental Protection Agency Solid Waste And Emergency Response (OS-220) 530R89120 EPA The Remedial Investigation Site Characterization and Treatability Studies This fact sheet is the second in a series of four that describes the remedial inves- tigation/feasibility study (RI/FS) pro- cess. Included within this fact sheet is a summary of Chapters 3 and 5 of the Interim Final Guidance for Conducting Remedial Investigations and Feasibility Studies Under CERCLA (October 1988, OSWER Directive No. 9355.3-01). These chapters discuss site characterization and treatability studies, respectively. Also included is information on how to manage these aspects of the remedial investigation (RI). The RI builds on activities initiated during scoping and includes implementation of the work plan (WP), the sampling and analysis plan (SAP), and the health and safety plan (HSP). Field data are col- lected and analyzed to determine the problems posed by a site and to support the identification of potential remedial actions. For sampling efforts to be better focused, it may be desirable to conduct iterative, and increasingly focused, field investigation rounds. Thus, the RI ob- jectives may be better balanced with time and resource constraints. A sche- matic of the major components that comprise the RI is presented in Figure 1. Treatability studies provide data on remedial technologies and their effec- tiveness on the specific waste found at a site. Ideally, the need for these investiga- UmknSwvqr Conduct Mite EwkMtNMtfFWRHMr 1 nwiMdfer ttons is identified during scoping, while the testing program is developed and implemented during the RI. Remedial Investigation Activities Conduct Field Investigations Field investigations define a site's physical characteristics as well as its sources, nature, and extent of contamination. In addition to characterizing a site, these activities may also be conducted to gather data on required design/operation parameters for the technologies being considered for remedial action. Because the RI and FS are interactive processes that are conducted concurrently. field investigation activities will be ongoing during the development and screening of remedial action alternatives. Sampling methods for obtaining site data are outlined in the Compendium o/Super/und Field Operations Methods (September 1987. OSWER Directive No. 9355.0-14); relevant chapters from this compendium are noted on Table 3-1 of the RI/FS Guidance. Note: Support activities are re- quired before conducting field in- vestigations «nd may take several month* to be completed. Activi- ties may include: » Obtaining access to areas of in- vestigation * Procuring subcontractors, equip- ment, and supplies * Selecting and coordinating with an analytical laboratory , » Procuring onsite facilities for RI activities Providing for storage/disposal of contaminated materials gener- ated during the RI Figure 1. Major Components of the Remedial Investigation ------- Define Site Physical Characteristics Data on the site's physical characteris- tics and the surrounding areas are col- lected to: (1) define potential transport pathways and receptor populations and (2) provide sufficient engineering data to develop and evaluate remedial action alternatives. Information used to define a site's physical characteristics includes: Site surface features 'Site geology Soil and vadose-zone characteristics Site hydrogeology Surface water hydrology Meteorological data Human population, land, and water use data Ecological information These data may be obtained from a variety of sources Including, but not limited to: historical photographs, topo- graphic surveys, site operational rec- ords, sampling/monitoring results. demographic information. USGS and zoning maps, and interviews with pres- ent/past site owners and employees. Characterize Sources of Contamination Source characterization includes defin- ing: (1) facility characteristics that iden- tify source locations; (2) the quantity of wastes that are either contained in, or have been released in, the environment; and (3) the physical and chemical char- acteristics of wastes present in the sources. As a part of source characteri- zation, the location, type, and integrity of waste containment structures (e.g., drums) are evaluated to determine the potential for substance release and its magnitude. The data required for source characterization are typically obtained through site Inspections, mapping. remote sensing, and sampling and analy- sis. Quantities of wastes are estimated either from verifiable Inventories of con- tainerized waste, from sampling and analysis, or from physical dimensions of the source. Characterize Nature and Extent qf Contamination The final objective of the field Investi- gation performed during the RI is to investigate the extent of contaminant migration. Including the volume of con- tamination and any changes in its phys- ical and chemical characteristics. This process involves using the information on physical site data and source location for a preliminary estimate of the locations of contaminants that may have migrated into the environment. An iterative monitoring program is then implemented so that, using increasingly accurate analytical techniques, the locations and concentrations of contaminants that have migrated can be denned. The final step is to ensure that the extent of contamination is confirmed with adequate data of sufficient quality to support riskassessmentand the analysis of remedial alternatives. The sampling and analysis approach used to determine the extent of contami- nation is discussed in Section 4.5.1 of U.S. EPA's Data Quality Objectives far Remedial Response Activities (March 1987. OSWERDirectiveNo. 9335.0-7B). Note: Because of the inherent un- certainties associated with Super- fund cites, it is impossible to de- finitively characterize the nature and extent of contamination at a site. Adequate site characteriza- tion requires data that meet DQOs. define the risks posed by a «Ue, demonstrate clearly the need for remedial action, and support the rationale for electing a remedial action alternative. Perform Data Analysis Laboratory Analys The type of laboratory chosen to analyze the site characterization samples may include a mobile laboratory, a labora- tory with whom the EPA has contracted under the contract laboratory program, (CLP), or a non-CLP laboratory. The type of laboratory selected will depend on the analytical services required, the number of samples to be analyzed, and the de- sired turnaround time. In many cases, it may be appropriate for more than one type of laboratory to be used. For ex- ample, mobile or non-CLP laboratories may be used for the quick analysis of screening level samples, while selected duplicate and/or split samples may be sent to CLP laboratories to confirm and validate the initial estimation of the nature and extent of contamination. Note: A combination of laboratory services, adequate to achieve the established DQO*. result* in more effective use of time and money. characteristics, sources of contamina- tion, the nature and extent of contami- nation, and the risk associated with the contamination. Defining the risks to human health and the environment is a function of the baseline riskassessmen The baseline risk assessment is ad- dressed in a separate fact sheet entitled. Risk Assessment Guidance far Super- fund: Human Health Evaluation Manual. This fact sheet is being prepared by the Hazardous Site Evaluation Division in the Office of Emergency and Remedial Response. Data Management The quality and validity of information generated during the RI must be effec- tively tracked by a data management system to allow it to be used to support remedy selection and any legal or cost recovery actions. The RI data manage- ment system should include: Field Logs-to document field investi- gation activities and observations, field measurements, -and any unusual circumstances or occurrences. Laboratory and QA/QC Reports-to provide chaln-of-custody and sample shipment records, analytical results, adherence to prescribed protocols, nonconformity events, correct*' measures, and data deficiencies. All records should be maintained throughout the RI/FS to ensure that only final and approved analytical data are used in the site analyses. Precau- tions should be taken to prevent the introduction of errors or the loss or misinterpretation of data. A data secu- rity system should be created to safe- guard and prevent free access to project records. Note: In some cave*, the use of non- validated data la warranted to prepare InteraalreviewdocumenU, to begin data analyst*, and to continue refining remedial action alternative*. Preliminary data, how- ever, can lead to improper conclu- sions and are, therefore, consid- ered unofficial. These data must be updated upon receipt of QA/QC The results of the RI are typically pre- sented as an analysis of site physical Define Contaminant Fate and Transport Results of the site physical characteriza- tion, source characterization, and extent of contamination analyses are combined to determine and project contaminant ------- fate and transport This involves deter- mining the actual and potential magni- tude of releases from the sources and *he mobility and persistence of source ntaminants. If information on contaminant release is available, the observed extent of con- tamination maybe used In assessing the transport pathways rate of migration and the fate of contaminants over the time span between release and monitor- ing. Contaminantfate and transport may also be estimated on the basis of site physical and source characteristics. Either type of analysis may be based on semi-analytical, analytical, or numeri- cal models. While field data generally best define the extent of contamination, models can interpolate among, and ex- trapolate from, isolated field samples to areas and times not sampled. Note: Modeling techniques to de- termine contaminant fate and transport may not be necessary if site conditions are well understood and if the potential effectiveness of different remedial actions can be easily evaluated. "define Contaminant- and sOcation-Specific ARARs Identification of potential applicable or relevant and appropriate requirements (ARARs) is initiated during scoping and continues throughout site characteriza- tion activities. During the RI, as a better understanding is gained of site condi- tions and contaminants, identification of contaminant- and location-specific ARARs continues to: (1) better plan fu- ture field activities, including identifying the scale of any required treatability studies, and (2) identify remedial action alternatives. The CERCLA Compliance with Other Laws Manual (Part I - August 1988 and Part II - August 1989, OSWER Directive Nos. 9234.1 and 9234.1-02) contains detailed information on identi- fying and complying with ARARs. Evaluate Additional Data Needs As data are collected, and a better un- derstanding of the site and the risks that it poses is obtained, the preliminary remedial action alternatives, initially identified during scoping, should be fur- ther refined. The available data should then be evaluated to determine if: (1) the DQOs have been met (2) the risks posed by the site have been adequately de- fined, (3) the need (or lack of need) for remedial action is documented, and (4) the data necessary for the development and evaluation of remedial action alter- natives have been obtained. Site char- acterization Is complete when these cri- teria have been met. Conduct Treatability Studies The need for treatability testing should be identified during project scoping to avoid delays in the RI/FS schedule. During scoping, a literature survey should be conducted to gather informa- tion on a technology's applicability, performance, implementability, relative costs, and operation and maintenance requirements. If practical candidate technologies have not been sufficiently demonstrated or cannot be adequately evaluated on the basis of available information (e.g., characterization of a waste alone is insufficient to predict treatment performance or the size and cost of treatment units) treatability testing should be performed. The treatability testing program will be designed and Implemented during the RI, while other field activities are under way. Design and implementation of a testing program will include: Preparation of a WP. SAP. and HSP Performance of field sampling, if re- quired Implementation of a testing program Evaluation of test results and docu- mentation in a report If the project plans developed for the RI/ FS do not adequately define the activi- ties to be performed during the treatabil- ity studies, a WP, SAP, and HSP must be developed before beginning the testing program. The required contents of these plans are listed in Appendix B of the RI/ FS Guidance. The decision to use a bench- versus a pilot-scale test is affected by a number of factors, including the level of develop- ment of the technology, the composition of the waste, and the nature and repre- sentativeness of the desired data. For a technology that is well developed and tested, bench studies may be sufficient to evaluate performance on new waste types. Pilot tests may be necessary if in- formation needed to operate the tech- nology at full scale Is limited, if there is a need to investigate secondary effects of the process, or if the waste being tested is complex or unique. Following the treatability testing pro- gram, an evaluation report will be pre- pared that analyzes and Interprets the test results considering the technology's effectiveness, Implementability, environ- mental Impacts, and cost Full-scale application of the technology will be evaluated and should include the identi- fication of key parameters and unknowns that can affect full-scale operations. Additional information on treatability studies can be found in a document entitled, Guide to Conducting TreatabH- tty Studies under CERCLA. This guide is currently being developed by the Office of Research and Development in their Risk Reduction and Engineering Labo- ratory in Cincinnati, Ohio. Note: The need for treatability stud- ies will result from initiating the alternative development process during scoping. A Technical Advi- sory Committee (TAG) should be used to achieve early consensus on potential remedial alternatives. Once the need for treatability test- ing has been identified, TAG support should continue with oversight of the development and implementation of the testing program as well as evaluation and interpretation of test results. (See Scoping Fact Sheet, OSWER Directive No. 8355.3-O1FS1, for additional information on the TAG.) Remedial Investigation Deliverables Preliminary Site Characterization Summary The preliminary site characterization summary is a concise summary of site data. This summary is developed after initial field efforts and: (1) provides a vehicle for the early sharing of ARARs with the support agency, (2) allows for early refinement of remedial alternatives, and (3) can be transmitted to the Agency for Toxic Substances and Disease Regis- try so that they may begin their required health assessment The format of the preliminary site char- acterization summary will be determined by the Region. The summary may be nothing more than a list of contaminants of concern and the affected media, or it ------- may be more extensive and review the investigative activities that have taken place. Draft RI Report The RPM reviews and approves the draft RI report after completion of RI activi- ties. This report summarizes the results of the field activities to characterize the nature and extent of contamination, the fate and transport of contaminants, and the results of the baseline risk assess- ment Table 3-13 In the RI/FS Guidance provides a suggested RI report format. RPM Responsibilities The RPM Is responsible for managing the project to meet the RI/FS objectives within the time and cost constraints. These responsibilities Include ensuring that adequate technical support is pro- vided, as well as schedule maintenance and financial control of the project Technical Support Techniques to assist In ensuring that adequate technical support Is provided to the project during the RI Include: Incorporate TAG participation throughout the RI to identify and resolve technical issues. When treat- ment is being considered for complex or difficult to treat waste, it is appro- priate for ORD's START team to be included on the TAG. See the Scoping Fact Sheet (OSWER Directive No. 9355.301FS1) for additional infor- mation on the START team and other technical experts. Communicate on a regular basis with all Involved parties (support agen- cies, consultants. TAG members) to reach a consensus on issues of con- cern and/or additional site work. Carefully consider the choice of ana- lytical services to minimize the time required to process samples while maintaining the needed data quality level. Consider the contractor's abil- ity to perform or subcontract analyti- cal services. Ensure that contractors performing treatability studies have adequate experience and the necessary per- mits. Schedule and Cost Control The management techniques listed under technical support also assist in control- ling schedule and cost Other schedule and cost control techniques include: When possible, provide conditional approval to portions of the work plan to begin field activities early. Be aware that Basic Ordering Agree- ments can be used by consultants to expedite the procurement of subcon- tractors. Consider weather conditions when scheduling field activities', extreme weather conditions may delay the schedule and/or Increase costs. Ensure that field contractors are trained in CLP procedures, including sample collection, shipment, and chain-of-custody requirements, to minimize the need to resample. Consider directing contractors to validate field data. Holdreviewmeetlngswlthallinvolved parties to expedite review of deltver- ables. * Review monthly financial statements from consultants and make sure that all costs are justifiable. Understand the components of labor hour costs and verify that activities are conducted by appropriate per- sonnel at the most effective level. Learn to anticipate cost and schedule problems based on the contactor's previous month's performance and take actions to minimize cost over- runs and schedule delays. Enforcement Considerations Potentially responsible parties (PRPs) may conduct all RI activities, Including any required treatability studies. It should be noted, however, that EPA reserves the right to conduct any aspect of the RI. As an example. EPA may conduct the baseline risk assessment since it serves as a primary means for supporting enforcement decisions. Both the administrative order (AO) and ap- proved WP represent the negotiated agreement between EPA and the PRPs on how the RI is to be conducted. Modi- fications to the scope of work must be approved by EPA before Implementation. As required by SARA. EPA will oversee all PRP activities with the assistance of a qualified third party. The objectives of such oversight include verifying that: (1) the RI/FS complies with CERCLA. *' NCP, and relevant Agency guidance; the work complies with the AO. State- ment of Work. WP. and SAP, (3) all work is performed to accordance with accept- able scientific and engineering methods; and (4) an adequate data base is devel- oped to support subsequent decisions and actions, either in the case of litiga- tion or the development of the Record of Decision. Additional Information on PRP participation in the RI/FS and PRP over- sight can be found in Appendix A of the RI/FS Guidance and in OWPE's Model Statement ofWofkforPRP-ConductedRe- medial Investigations and Feasibility Studies (June 2. 1989). Points to Remember » Initiate field support actlvttle' early and allow enough time i the schedule to complete them, Use DQOs to determine the qual- ity of data needed from each field activity. Create a data management sys- tem for all RI activities. » Minimize the need to mobilize/ demobilize contractors. Use field-screening techniques and mobile laboratories, where appropriate. Turn data over to contractors for pre-analysls before data valida- tion. Develop and implement the treatability testing program dur- ing the RI. Continue theidentiflcationofcon- taminant- and location-specific ARARs. * Communicate regulatiy with all involved parties. * Incorporate TAG participation throughout the RI ------- |