Hazardous waste rules require owner/operators of facilities that store, treat or dispose of hazardous waste to be subject to, among other things, closure and post-closure requirements.
Closure is the period directly after a hazardous waste treatment, storage or disposal facility (TSDF) stops its normal operations. During this period, a TSDF stops accepting hazardous waste; completes treatment, storage, and disposal of any wastes left on site; and disposes or decontaminates equipment, structures, and soils. Some owners and operators will completely remove all waste that was treated, stored, or disposed in their unit. This operation is known as clean closure. In order to demonstrate clean closure, an owner and operator must show that levels of hazardous contaminants at the facility do not exceed EPA-recommended exposure levels.
If you store, treat, or dispose of hazardous waste, you are likely subject to the hazardous waste closure requirements.
Closures are unit-based activities whereas Corrective Action is site-wide. In closure, it is important to define the physical boundaries of the hazardous waste management unit subject to closure based upon the hazardous waste, hazardous waste constituents, or breakdown products associated with hazardous waste managed at the unit.
In instances where hazardous constituents are found to be present at or near the closure unit but are not attributable to the unit activities, Ohio EPA has several alternatives. The hazardous constituents found within the unit boundary can be addressed as a part of the closure process; as such the unit will not be investigated during Corrective Action. Alternatively, the unit can be closed addressing only the hazardous waste managed at or attributable to the unit (without addressing the other hazardous constituents); the closed unit will then be subject to Corrective Action investigation.
Hazardous constituents outside the closure unit boundary may be addressed through Corrective Action or other programs available through the state. In cases where the closure unit has released hazardous waste or constituents into the surrounding soil or ground water and the closure units are located near Waste Management Units (WMUs) or Areas of Concern (AOCs) that also had releases to the environment, the clean-up of similar releases may be subject to two different set of standards and procedures. Therefore Ohio EPA may address the closure unit under Corrective Action by exempting the closure unit from certain closure requirements conditioned on the incorporation of the unit into the Corrective Action program through a permit or order.
RCRA Corrective Action
Facilities generally are brought into the RCRA corrective action process through orders when there is an identified release of hazardous waste or hazardous constituents from waste management units (WMU), or when Ohio EPA is considering a facility’s RCRA permit application. Additionally, a facility owner or operator may volunteer to perform corrective action by entering an agreement with Ohio EPA in order to expedite the process.
The RCRA Corrective Action program investigates and remediates waste management units (WMUs) on a site-wide basis, as necessary, which are typically permit or order driven. Unlike the closure process, which provides two options (closure by removal and closure with waste in place) the Corrective Action process provides considerable flexibility to Ohio EPA to choose a remedy that reflects the conditions and the complexities of each facility. For example, depending on the site-specific circumstances, remedies may attain media cleanup standards through various combinations of removal, treatment, and engineering and institutional controls.
Where a collection of adjacent WMUs and a hazardous waste management unit undergoing closure are releasing hazardous constituents to the environment, two separate remedial processes would apply to the cleanup of the respective releases. Many times, the regulatory distinction between the WMU and the closure unit cannot be maintained because unit boundaries overlap, contaminant plumes are commingled, or it is difficult to identify the exact source of the contamination. The post-closure rule developed by U.S. EPA, and effective in Ohio as of December 7, 2004, addresses this situation by allowing the hazardous waste management unit to be addressed under Corrective Action. This rule allows the regulating agency to choose whether to apply current 40 CFR Parts 264 and 265 (or OAC Chapters 3745-54 to 3745-205 and 3745-65 to 3745-256) to hazardous waste management units closed as a part of a broader Corrective Action or to address them through the Corrective Action cleanup requirements. However this rule was not intended as a way to bring WMUs under the unit-specific closure standards. For more information on RCRA Corrective Action, please go to the link for RCRA Closure Guidance on DERR’s Cleanup under RCRA web site.