Each year, EPA selects new construction projects for funding based primarily on prioritization of those sites that present the greatest risk to human health and the environment.

To make the most efficient use of funds, the remedial program prioritizes funding for previously mobilized, ongoing construction projects over the funding to start new construction projects. As a result, EPA may not be able to fund new construction work at some NPL sites that otherwise may be ready for new construction work.

Many Superfund sites have multiple construction projects planned as part of the overall site remedy. Typically, EPA has already expended funds elsewhere on the sites included in the new construction projects awaiting funding list to address immediate health and environmental risk. Unfunded construction projects result when a potentially responsible party is not found or cannot pay, and no other funding sources, including appropriated funds, are available.