Colorado Department of Pub lic Health and Environment

Hazardous Materials and Waste Management Division Policies

Policy Title: End of Post-Closure Care

Program(s) Initiating the Policy: Solid & Hazardous Waste Program

Program(s) Subject to the Policy: Solid & Hazardous Waste Program

Statutory and Regulatory Citation s: 6 CCR 1007-3, §264.117(a) and §265.117(a)

Policy Purpose:

Since the inception of the federa l Resource Conservation and Recovery Act (RCRA) and its state equivalent, the Colorado Hazardous Waste Act (CHWA), one focus of the regulatory program has been to require facilities th at treat, store or dispose of h azardous waste to either obtain a permit to continue operating or to close their regulated units. Cl osures that result in leaving waste and/or contamination behind, thereby creati ng a landfill, require the facility to perform long-term post-closure care of the hazardous wast e management unit. The purpose of this policy is to define the criteria by which the Departme nt will determine that the regulatory requirements for closure have been satisfied and post-clo sure care of the regul ated unit may cease.

Policy:

6 CCR 1007-3, §264.111 and §265.111 of the Colorado Hazardous Waste Regulations establish performance standards for regulated units at clos ing facilities, consisting primarily of activities that a) minimize the need for further maintena nce and controls, and b) minimize or eliminate
future releases of hazardous waste and constitu ents to the degree necessary to protect human health and the environment. Although a facility may have successfully achieved these standards,
the fact that not all hazardous waste and constituents have been removed from the facility triggers the need for long-term maintenance a nd monitoring of the hazardous waste management unit during the post-closure care peri od. 6 CCR 1007-3, §264.117(a) and §265.117(a) state “Post-closure care for each hazardous waste management unit...must begin after completion of
closure of the unit and continue fo r 30 years after that date.” Th ese sections go on to state that the Department may at any time during the post- closure care period either shorten or lengthen the post-closure care period applicable to the hazardous waste management unit and the wastes managed therein.

Accordingly, the Department may decide that post-closure care is no longer required at a hazardous waste management unit if human h ealth and the environment are sufficiently protected. Although these sections do not require evaluation of spec ific criteria, they do suggest factors that may be considered in making the d ecision to shorten or e nd the post-closure care period. These factors include en vironmental monitoring results, ch aracteristics of the waste andcharacteristics of the unit that might suggest the f acility is secure, stable and predictable in its present and anticipated future state.

CDPHE Criteria for Ending Post-C losure Care and Maintenance

Post-closure care under the CHWA may end at regulated units when one of the following
conditions is satisfied:

1) The regulated unit is clean closed, either by removing the waste and any associated contamination, or by delisting the waste, render ing it non-hazardous for management as a solid waste either within the existing unit or at some other solid waste facility; or

2) The Department approves, in accord ance with 6 CCR 1007-3, §264.117(a)(i) or §265.117(a)(i), a proposal to end post-closure care after completing a performance-based evaluation that considers all relevant unit design and environmental factors to determine that the hazardous waste unit is secure and protective of human health and the environment. The data
and site information to be evalua ted include, but are not limited to:

• Leachate monitoring results (quality and quantity)

• Ground water monitoring results

• Characteristics of the hazardous waste

• Hydrogeologic characteristics of th e formation beneath and around the unit

• Overall design of the unit to minimize long-term maintenance, resist the generation of leachate and contain the waste in perpetuity

• The potential for waste or constituents to migrate from the regulated unit

• Management and maintenance history of the unit (including cap and liner)

• End-use strategy and the enforceable mechanis m ensuring the continued use and care of the property

The Department will review the information provi ded, and will consider releasing the unit from long-term post-closure care only if the following conditions are met:

• The waste in the regulated unit is and will continue to be stable;

• There have been no releases from the unit in th e past, or if a release did occur, corrective measures were implemented successfully and subsequent monitoring shows no evidence of a reoccurrence;

• The unit configuration/design ensures that a re lease or exposure to the waste is unlikely or nonexistent;

• Little or no maintenance is required to preven t the migration of or exposure to the waste;

• The institutional controls in the environm ental covenant would ensure the preceding conditions would continue in perpetuity;

• Even if a release were to occur from the unit in the future, the anticipated impact to
human health and the environment would be minimal and may not justify an active

response.