Whose responsibility is it to maintain curbs and sidewalks in the Borough?

This responsibility belongs to the property owner.  The PMPCA specifically states:

1. The borough may also require owners of property abutting on any street or State highway to grade, construct, drain, pave and repave the sidewalk, curb or gutter and keep them in repair and in safe and usable condition along the property at the grades and under the regulations and specifications as council may prescribe.