Costs for groundwater monitoring during remediation represent a significant, persistent, and growing burden for the private entities and government agencies responsible for environmental remediation projects, especially as remedies are determined and implemented. Long-term monitoring (LTM) is defined here as monitoring conducted after some active, passive, or containment remedy has been selected and put in place, and is used to evaluate the degree to which the remedial measure achieves its objectives (e.g., removal of groundwater contaminants, restoration of groundwater quality, etc.). It usually is assumed that after a site enters the LTM phase of remediation, site characterization is essentially complete, and the existing monitoring network can be adapted, as necessary, to achieve the objectives of the LTM program.

EPA 542-R-05-003. "May 2005." " ... EPA's Office of Superfund Remediation and Technology Innovation."--Page 2. Includes bibliographical references.

Introduction -- Benefits of optimization of long-term monitoring programs -- Purpose -- Scope -- Steps involved in long-term monitoring optimization -- Clearly define and document current monitoring program -- Examine existing data -- Determine the type of evaluation -- Select the LTMO method(s)/tool(s) -- Perform the optimization -- Assess and implement results -- LTMO resources.