Superfund Information Systems: Site Profile

Superfund Site:


Operable Units

Below, EPA has provided a list of the remedial actions selected pertaining to each operable unit.

EPA issues Records of Decision (RODs) to explain which cleanup methods will be used at Superfund National Priorities List sites. EPA has two primary documents that it may use to identify changes to the remedies selected in RODs. EPA uses a ROD Amendment when it needs to make a fundamental change to the remedy. EPA publishes an Explanation of Significant Differences (ESD) for significant changes.

During cleanup, complex sites may be divided into several distinct areas to make the response more efficient. These areas, called operable units (OUs), may address geographic areas, specific problems, or medium (e.g., groundwater, soil) where a specific action is required. The remedies are displayed for the OU numbers indicated in the original decision document. OU numbers may change over time.

EPA is working to improve data quality. The information presented on this page is undergoing review for accuracy and completeness, and may be subject to change.

OU ID Name Decision Document Cleanup Technologies Selected
in the Decision Document
00 SITEWIDE Not applicable
01 WATER SYSTEM Record of Decision
April 14, 1984
Water Supply (permanent replacement, other, NOS)
01 WATER SYSTEM Record of Decision Amendment
August 07, 1985
Water Supply (permanent replacement, other, NOS)
02 RESERVOIR Record of Decision
December 15, 2004
Disposal (offsite)
Hydraulic Control (containment)
Institutional Controls
Monitored Natural Attenuation
03 MAINSTEM RIVER Record of Decision
April 29, 2004
Disposal (offsite)
Slope Stabilization
Treatment (other, NOS, onsite)
03 MAINSTEM RIVER Explanation of Significant Differences
June 12, 2015
ESD/Amd - Remedy Element Addition/Modification

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