To carry out this chapter, any Federal agency responsible for a construction project may assist the Secretary or may transfer to the Secretary funds as may be agreed on, but not more than 1 percent of the total amount authorized to be appropriated for the project, except that the 1 percent limitation under this section shall not apply if the cost of the project is $50,000 or less. The costs of the survey, recovery, analysis, and publication shall be deemed nonreimbursable project costs.

Amounts appropriated for purposes of this section shall remain available until expended.