Interim Remedial Measures (TAGM - 4042)

Issuing Authority: Michael J. O'Toole, Jr.
Title: Director, Division of Environmental Remediation
Date Issued: June 1, 1992

Purpose

The intent of this TAGM is to provide guidance which helps decision makers properly and consistently define and track Interim Remedial Measures conducted at sites listed on the Registry. IRM procedures will be discussed in future TAGMs.

Definition

An Interim Remedial Measure or "IRM" means a discrete set of activities to address both emergency and non-emergency site conditions, which can be undertaken without extensive investigation and evaluation, to prevent, mitigate, or remedy environmental damage or the consequences of environmental damage attributable to a site listed in the Registry. Its purpose is to lessen obvious hazardous waste risks to the environment and/or public health. IRMs are intended to function as a temporary rather than final remedial response to the problem. However, the IRM should serve to reduce the scope and cost of the final remedy. An IRM may become the final remedy if it achieves the goal of restoration of the site to predisposal conditions (to the extent feasible and authorized by law) and minimally achieves the elimination or mitigation of all significant threats to the public health and/or to the environment presented at the site.

For project tracking purposes, IRMs should be perceived as a program element, not an operable unit. An IRM is a component of a comprehensive remedial program for an operable unit. A comprehensive remedial program generally includes an RI/FS, Design, Construction, O&M plus any associated IRMs. The term "operable unit" means a discrete portion of a program that may address geographical portions of a site, specific site problems, or initial phases of a program; and that manages migration or that eliminates or mitigates a release, threat of release, or pathway of exposure.

Several types of IRMs exist. The term IRM includes but is not limited to the following activities: removals of wastes and contaminated materials including environmental media (e.g., drum removals, soil removals, removals of contents from lagoons and settling basins, removals of floating product on groundwater table); construction of diversion ditches, collection systems, or leachate collection systems; construction of fences or other barriers; installation of water filters or provision otherwise of alternative water supplies.

Interim Remedial Measure vs. Remedial Construction

Included in the list of IRM activities are actions which have traditionally been considered as remedial construction activities. Therefore, to facilitate distinguishing IRMs from remedial construction projects, the following criteria are provided:

Timing of the Action: An IRM conducted as part of an operable unit generally is done before an RI/FS is completed. On the other hand, a remedial construction project occurs after an RI/FS is completed. The remedial construction project is dictated by the Record of Decision which is completed at the end of the RI/FS.
Purpose of the Action: An IRM is intended to serve as a temporary and/or partial response to the problem. A remedial construction project is intended to be the final or part of the final and complete response to the problem. Sometimes, however, an IRM proves sufficiently effective that the Record of Decision selects the no further action alternative and the site can legitimately be reclassified as "cleaned up", (Class 4, 5 or D2).
Complexity of the Remedial Response: An IRM is generally a less complex type of remedial response and a much less detailed design, if any, is a prerequisite to the action. A remedial construction project is more complex, necessitating a conventional, fully detailed design.
Degree of Thoroughness of the Response: An IRM must conform to appropriate standards and criteria unless conformity is waived for good cause, including without limitation that the subsequent remedial construction will be in conformity with such standards and criteria; and IRM should conform to appropriate guidance. Remedial construction projects must always attain the SCGs stipulated in the Record of Decision.

Interim Remedial Measures vs. EPAs or DECs Emergency Response Action

IRMs and Emergency Response Actions are generally similar in type and purpose. In an effort to be able to account for and track all significant actions occurring at an inactive hazardous waste site, the following criteria are provided to distinguish IRMs and Emergency Response Actions.

Degree of Significance: IRMs are significant rather than incidental actions. Removal of a single barrel of hazardous wastes would be an example of an incidental action. Emergency Response Actions include both significant and incidental actions. By definition an emergency means a spill, or other event or condition, whether natural or human-made, as the result of which a release or threat of release of hazardous waste presents an immediate threat to life, health, property or natural resources.
Degree of Urgency: IRMs address problems which may or may not command an urgent response. In contrast, Emergency Response Actions are performed only in emergency situations.
Location: IRMs are conducted only at sites listed on New York State's Registry of Inactive Hazardous Waste Sites. Emergency Response Actions may occur at both non-listed and listed sites. When a significant Emergency Response Action occurs at a listed site, it will be tracked in New York State's Hazardous Waste Site Project Tracking System as an IRM. When a significant Emergency Response Action occurs at a location, which becomes listed on the Registry at a later date, the project will then be identified and tracked as an IRM in New York State's Hazardous Waste Site Tracking System.