The purpose of the Remedial Investigation/Feasibility Study (RI/FS) is to characterize the nature and extent of risks posed by the release of hazardous substances, pollutants, or contaminants and to evaluate potential remedial options.
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The RI characterizes the site and assesses the baseline risks to human health and the environment. The FS screens and evaluates remedial alternatives so that an appropriate remedy can be selected. To the extent possible, the RI/FS should be performed as an integrated effort to ensure that data obtained in the RI are appropriate to evaluate likely remedial alternatives during the FS.
The RI is the investigative phase of the response action and begins with site characterization. The RI further develops and refines the conceptual site model (CSM) to support remedy selection and design. The RI must follow the Department of the Navy’s (DON’s) Systematic Planning requirements including the preparation of an approved Sampling and Analysis Plan (SAP) in accordance with the Uniform Federal Policy for Quality Assurance Project Plans (UFP-QAPP). Key considerations in the RI phase include:
- Characterizing site conditions to determine the nature and extent of contamination from historical site releases;
- Evaluating potential current and future risks to human health and the environment based on exposure to historic site releases;
- Providing a basis for further evaluation, response action, or no further action (NFA); and
- Obtaining data for the evaluation of remedial alternatives if the site poses an unacceptable risk.
- Please see the Risk Assessment Web page for information on human health and ecological risk assessments conducted as part of the RI.
The primary focus of the FS is to ensure that appropriate remedial alternatives are developed and evaluated in such a manner that the information can be presented to decision makers and an appropriate remedy can be selected. Key considerations in the FS phase include:
- Identifying applicable or relevant and appropriate requirements (ARARs);
- Developing remedial action objectives (RAOs) and site-specific cleanup goals and ensuring RAOs are specific, measurable, relevant, and timely;
- Developing, screening, and evaluating remedial alternatives in accordance with the nine criteria described in the National Contingency Plan (NCP) ;
- Optimizing remedial options to be implementable, cost-effective, and to minimize environmental footprints; and
- Providing sufficient information about the alternatives to allow for sound decision making and to support consensus among regulatory authorities regarding the remedy selection in the Proposed Plan (PP).
The process of identifying, evaluating, and selecting the appropriate remedy begins with a review of remedial technologies and methods that are appropriate to address the site risks. Information about common and innovative technologies can be found on the Federal Remediation Technologies Roundtable (FRTR) Technology Screening Matrix. In addition, presumptive remedies should be considered at all applicable sites according to EPA guidance.
NAVFAC has several policies and guidance documents that impact remedy evaluations in the FS phase related to optimization, remedial alternatives analysis (RAA), quality document reviews (QDRs), and green and sustainable remediation (GSR) metrics. The DON Guidance for Optimizing Remedy Evaluation, Selection, and Design provides additional FS phase considerations.
The initial step of developing the RI/FS is the scoping process. Early planning and collaboration among the stakeholders (Remedial Project Manager [RPM], contractors, and regulators) are key to a successful scoping process. The RAA review is required during the scoping of the FS report and prior to submittal to the regulatory agencies.
The end product of an RI/FS is the comparison of remedial strategies supported by valid site data and a risk assessment, which allows decision makers to ultimately select the most appropriate remedy or combination of remedies for a site. A QDR is also required for the RI/FS prior to submittal to regulatory agencies.
For more information, Chapter 8 of the DON Environmental Restoration Program Manual details RI/FS considerations.