Frequent Questions

What is the difference between an area of contamination (AOC) and a corrective action management unit (CAMU)?

The Resource Conservation and Recovery Act (RCRA) provides management standards for hazardous waste in specific types of units. In addition to the traditional units such as tanks and containers, EPA has established other units as flexible options for corrective action including the area of contamination (AOC) and corrective action management unit (CAMU). Both of these options require a designation by your state's implementing agency. 

In what is typically referred to as the AOC policy, EPA interprets RCRA to allow certain discrete areas of generally dispersed contamination to be considered RCRA units (usually landfills). Because an AOC is equated to a land-based unit, consolidation and in-situ treatment of hazardous waste within the AOC do not create a new point of hazardous waste generation for purposes of RCRA. This interpretation allows wastes to be consolidated or treated in situ without triggering land disposal restrictions or minimum technology requirements. The AOC interpretation may be applied to any hazardous remediation waste that is in or on the land. 

A CAMU is specifically designated for treatment, storage, or disposal of hazardous remediation waste. The main difference between CAMUs and the AOC policy is that when a CAMU is used, waste may be treated ex situ and then placed in a CAMU, CAMUs may be located at an uncontaminated facility, and wastes may be consolidated into CAMUs from areas that are not contiguously contaminated. 

This clarification is provided in the following guidance document: 
Memo, Fields and Herman to Regions 1-10; October 14, 1998 (RCRA Online #14291
This guidance document is available in the RCRA Online database at the following URL:

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