Long-term stewardship (LTS) is the last stage of the cleanup process. Safeguards are put in place in order to protect human health and the environment when contamination remains on a site. The EPA formed the LTS Task Force in 2004 to evaluate the state of long-term stewardship across its various waste cleanup programs. SIRS has established this concept in Delaware to manage LTS issues for sites at the state level. It is important to recognize that LTS should be actively considered in the remedial action planning, life cycle projection, design, cost/funding implementation and decision-making process. This consideration may result in the implementation of a more cost-effective remedial action where no restrictions on the property are required.
Two subsets under Long-term stewardship (LTS) are operations and maintenance (O&M) and institutional controls (IC). Operations and maintenance are more active, and usually involve inspections of the remedial action, depending on the specifications of the O&M Plan. Institutional controls are more passive, and usually involve administrative policies that restrict the use of or activities at a property to prevent the risk of exposure.
One common type of institutional control is a Groundwater Management Zone (GMZ). A GMZ is a delineated land area adjacent to and including a contaminated site where DNREC has determined that new drinking water wells must be restricted in order to protect public health and safety. The GMZ map and associated restrictive language define the area where DNREC will restrict water wells as detailed in a Memorandum of Agreement between the Division of Water and the Division of Waste & Hazardous Substances. A GMZ is put in place when there is a "technical impracticability" where the nature or extent of groundwater injury prevents remediation.
Another common type of institutional control is a Uniform Environmental Covenant Act (UECA). UECAs are more commonly referred to as deed restrictions and they run with the land. They are put in place to restrict future land usage due to residual contamination. They inform future site workers and site visitors to contact DNREC should proposed activities interfere with the remedy.