42 U.S.C. § 12655j

Program agencies may use volunteer services for purposes of assisting projects carried out under this division and may expend funds made available for those purposes to the agency, including funds made available under this division, to provide for services or costs incidental to the utilization of such volunteers, including transportation, supplies, lodging, recruiting, training, and supervision. The use of volunteer services under this section shall be subject to the condition that such use does not result in the displacement of any participant.