; and (2) are caused by operations of the rail operator. (b) Revised Maps If a change in the rail operations of rail operator described in subsection (a) establishes a substantial new nonconforming noise level on the property of a school located in an urbanized area, or significantly reduces nonconforming noise levels on the property of such a school, that is not reflected in the noise exposure map, the rail operator shall submit a revised noise exposure map to the Secretary showing the new nonconforming noise levels or noise level reduction. 6. Noise compatibility programs (a) Program submission A rail operator that submitted a noise exposure map under section 5 may submit a noise compatibility program to the Secretary of Transportation after— (1) consulting with public agencies and planning authorities in the area covered by the map; and (2) notice and an opportunity for a public hearing. (b) Contents of program A program submitted under subsection (a) shall state the measures the rail operator has taken or proposes to take to reduce existing nonconforming noise levels on the property of a school and prevent creating additional nonconforming noise levels in the area covered by the map. The measures may include constructing barriers or acoustical shielding and soundproofing of schools subject to a nonconforming noise level. (c) Approvals The Secretary shall approve or disapprove a program submitted under subsection (a) of this section not later than 180 days after receiving it. The Secretary shall approve the program if the program— (1) is reasonably consistent with achieving the goal of reducing nonconforming noise levels on the property of a school and preventing the introduction of additional nonconforming noise levels on the property of a school