Recommended Practice for Constr uction Parallel to Existing Underground Transm ission Pipelines Emphasis of these guidelines is on the interaction between existing transmission pipeline operators and those planning to construct in a parallel fashion. These activities may involve many different parties. Contractors working on behalf of the constructing party, including environmental and survey professionals, de sign engineers, constr uction contractors, and operators of excavation and earth moving equipment, should engage in work practices that are in conformance with these guidelines and apply vigilance in identifying u ticipated circumstances that may indicate a problem. This