The town's engineering firm underestimated the original $6.6 million dollar project.
Belmar administrator Colleen Connolly says Birdsall Engineering based the reconstruction on the walkway being 25 feet wide. However, the boardwalk is wider than that in spots.
Connolly also says beach ramps need to be reconfigured to comply with the Americans With Disabilities Act.
The town council will review the change order at its Wednesday night meeting.