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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. 

Jump to Resources to access Policies & Guidance, Publications, Related Sites, and Tools



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.

Remedial Investigation

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.


Feasibility Study

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 optimizationremedial 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. 



Title and Description

ERP Manual

DON Environmental Restoration Program Manual: Chapter 8 RI/FS (February 2018)
Describes the steps taken to advance an Environmental Restoration Program (ERP) site through the RI/FS phase.

​RAA Guidance

Naval Facilities Engineering Command Guidance for Remedial Alternatives Analysis (October 2020)
This guidance document describes the requirements for RAAs, the procedures for RAA preparation, and the review process for RAAs. This document updates the RAA guidance issued in April 2012. A detailed template for preparing the RAA is attached.

Munitions Response Program


Munitions Response (MR) Remedial Investigation/Feasibility Study (RI/FS) Guidance (June 2019)
This guidance document includes an overview of the U.S. DON MRP, the regulatory framework governing investigations, and response actions under the MRP.

Document Review

NAVFAC ER,N Program Directive for Quality Document Review (QDR) of DON Installation Restoration Program (IRP) Sites (June 2018)

Summarizes the process for obtaining the required internal reviews of key documents including the FS.


EPA Best Practice Process for Identifying and Determining State Applicable or Relevant and Appropriate Requirements (ARAR) Status Pilot (October 2017)

Establishes a pilot process for meeting the CERCLA requirement to identify and determine state and federal ARARs when selecting remedial cleanup actions.

Optimization Policy

DON Policy for Optimizing Remedial and Removal Actions at All DON Environmental Restoration Program Sites (April 2012)

Clarifies when to perform optimization reviews and provides effective remedial strategies to meet remedial action objectives. Requires consideration of: 1) GSR metrics; 2) RAA; and 3) the Management and Monitoring Approach (MMA).

GSR Metrics

DON Guidance on Green Sustainable Remediation (April 2012)

Discusses how to incorporate GSR metrics into projects. Methods for evaluating remedy footprint are discussed, along with case studies and recommended strategies for footprint reduction.

Remedy Evaluation

DON Guidance for Optimizing Remedy Evaluation, Selection, and Design (March 2010)

Provides a general overview and explanation of key optimization concepts as they pertain to the FS, Record of Decision (ROD), and Remedial Design (RD) and provides specific recommendations for optimizing remedy selection and design.

Site Closeout

DON Guidance to Documenting Milestones Throughout the Site Closeout Process (March 2006)

Outlines a consistent approach for documenting specific milestones for achieving site closeout.

Site Closeout

DoD/EPA Joint Guidance on Streamlined Site Closeout and NPL Deletion Process For DoD Facilities (January 2006)

Streamlines the site closeout and National Priorities List (NPL) deletion process for DoD facilities.


Title and Description

Incremental Sampling

Advantages and Limitations of the Incremental Sampling Methodology (ISM) for Navy Projects (Aug 2020)

Incremental sampling methodology (ISM) is a structured composite sampling and processing protocol that is designed to reduce data variability and provide a reasonably unbiased estimate of mean contaminant concentrations in a volume of soil.

Mass Discharge


Tools for Estimating Contaminant Mass-in-Place, Mass Discharge, and Remediation Timeframes (August 2018)

Provides an overview of tools and techniques to estimate contaminant mass-in-place, contaminant mass discharge, and remediation timeframes. Case studies illustrate how tool results improved site-specific remedial strategies.

ARARs Toolkit

NAVFAC Toolkit for Identifying Applicable or Relevant and Appropriate Requirements (ARARs) (August 2014)

Outlines the key concepts in identifying and documenting ARARs.

GSR Metrics

Integrating Green and Sustainable Remediation Metrics within the CERCLA Process during the Feasibility Study (July 2012)

Focuses on Navy GSR metrics and their incorporation into the nine criteria for alternatives analysis during remedy evaluation phase. An example case study is also provided.

Cost Estimate

EPA – A Guide to Developing and Documenting Cost Estimates During the Feasibility Study (July 2000)

This guidance document addresses cost estimates of remedial alternatives developed during the remedial investigation/feasibility study. The goals of this guidance are to improve the consistency, completeness, and accuracy of cost estimates developed to support the Superfund remedy selection process. To help achieve these goals, the document presents clear procedures and expectations, a checklist of cost elements, and example formats. It also identifies resources for estimating costs during the feasibility study.


Title and Description

Chlorinated Solvents


Protocol for Selecting Remedies for Chlorinated Solvent Releases (ER-200530)

This guide is intended to assist decision makers with selecting remedies for releases of chlorinated solvents to the subsurface environment. Content includes a review of the nature of the problem, consideration of the critical components of setting objectives, a current overview of available options, and suggestions for developing comprehensive remedial packages



FRTR Technology Screening Matrix

A user-friendly tool for screening potentially applicable technologies for a remediation project. Covers in situ and ex situ technologies for soil and groundwater remediation. Variables used in screening include contaminants, development status, overall cost, and cleanup time.

Chlorinated Solvent


Matrix Diffusion 


A software application used for simulating the transient effects of groundwater source and chlorinated solvent plume remediation that takes into account matrix diffusion.





ESTCP BioPic Tool

A tool to perform screening to determine the most appropriate remedial option among monitored natural attenuation (MNA), biostimulation, biologically mediated abiotic reductive dechlorination, or bioaugmentation

Environmental Restoration



Enviro Wiki Webpage

This webpage makes scientific and engineering research results more accessible to the target audiences, facilitating the permitting, design and implementation of environmental projects. Articles are written and edited by invited experts to summarize current knowledge for environmental professionals on an array of topics, with cross-linked references to reports and technical literature

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