Pennsylvania Code
Title 25 - ENVIRONMENTAL PROTECTION
Part I - Department of Environmental Protection
Subpart C - Protection of Natural Resources
Article II - Water Resources
Chapter 105 - DAM SAFETY AND WATERWAY MANAGEMENT
Subchapter C - CULVERTS AND BRIDGES
DESIGN CRITERIA FOR CONSTRUCTION OR MODIFICATION
Section 105.163 - Bridge piers

(a) Bridge piers shall be kept to a minimum in number and cross-sectional area and shall be designed to offer the least obstruction to the passage of water and ice, consistent with safety.

(b) Bridge piers in channels subject to unstable or super critical flow shall require special investigation and shall be so designed as to prevent the creation of excessive backwater and waves downstream of the pier.