Congressional Budget Office Cost Estimate: S. 1447: Diesel Emissions Reduction Act of 2017 [open pdf - 89KB]
"S. 1447 would authorize the appropriation of $100 million annually through 2022 for the Environmental Protection Agency (EPA) to provide grants for projects and state programs that reduce emissions from diesel engines. The bill also would require the EPA to provide guidance to states about technical differences in vehicles, engines, equipment, and vehicle fleets. Finally, the bill would specify that any funds not claimed by states for diesel programs be reallocated for projects that retrofit vehicles. Assuming appropriation of the authorized amounts, CBO [Congressional Budget Office] estimates that implementing S. 1447 would cost $480 million over the 2018-2022 period. Enacting the bill would not affect direct spending or revenues; therefore, pay-as-you-go procedures do not apply. CBO estimates that enacting S. 1447 would not increase net direct spending or on-budget deficits in any of the four consecutive 10-year periods beginning in 2028. S. 1447 contains no intergovernmental or private-sector mandates as defined in the Unfunded Mandates Reform Act (UMRA) and would impose no costs on state, local, or tribal governments."
Congressional Budget Office: https://www.cbo.gov/