Any person or company maintaining any underground natural gas distribution system on public right-of-way within the City shall periodically test for leaks in accordance with the Pennsylvania P.U.C. "Gas Regulations" and/or the U.S.A. Standard Code for Pressure Piping, "Gas Transmission and Distribution Piping Systems," otherwise known as USAS B31.8-1968 as revised periodically. If leaks of a magnitude likely to affect tree growth are discovered, repairs shall be made with reasonable promptness so that no injury shall be done thereby to any trees or shrubs. (Ord. 14-1970 §7.)