Hazardous waste facilities will eventually stop generating and/or receiving waste for treatment, storage or disposal. At that time, the owner/operator must either remove all waste that has accumulated in hazardous waste management units at the facility, or leave the waste in place while maintaining the units in such a way that ensures they will not pose an unacceptable future threat to human health and the environment. This is referred to as RCRA closure.
Past and present activities at hazardous waste facilities have sometimes resulted in releases of hazardous waste and hazardous constituents into soil, ground water, surface water, sediments and air. Hazardous waste regulations mandate that facilities investigate and clean up, or remediate, these releases. This program is known as RCRA corrective action.