Agenda - Council - 06/25/2013 - Laserfiche WebLink

Home

Enterprise Park to Crooked Lake 115 kV Transmission Line March 2012 Environmental Assessment 4. Facility Construction Construction of the Project would begin following the decision of the Commission and the issuance of required permits and approvals. Prior to construction, all easement rights and ROW must be acquired and soil conditions established to finalize the construction design. The Applicant has stated the Project will be designed in compliance with the latest industry standards, as well as environmental and other permit conditions. This includes adherence to National Electric Safety Code (NESC) standards regarding clearances to ground, clearance to crossing utilities, clearance to buildings, right-of-way widths, erecting power poles, and stringing of transmission line conductors. The Applicant has stated it typically uses outside contractors for construction activities on large transmission line projects. The contractor is required to construct the line in accordance with specifications developed by the Applicant's Engineering and Project Management Depatttnent. A copy of the Applicant's easement restriction list, environmental restriction lists, and any required local permits are given to the awarded contractor prior to construction. The Applicant has stated the proposed 115 kV transmission line would be constructed at existing grade elevations. Therefore, no pole locations would require grading, unless it is necessary to provide a level area for construction access and activities. Typical tangent structures will be wood, laminated wood, or steel direct -embedded poles. The structures will require a hole dug 10 to 15 feet deep and 3 to 4 feet in diameter for each pole. Any excavated soil that is not backfilled will be thin spread or removed from the site as required. The poles may be backfilled with native soils, crushed rock or concrete depending on design conditions. In lowland areas, a galvanized steel culvert may be also inserted for pole stability if soil capacity is poor. Due to the congested development throughout the Project area, angle structures will typically be self supported and attached to a drilled concrete pillar foundation. The pillar will typically have a diameter of 4 to 8 feet. The hole may require a depth of 15 to 30 feet depending on design requirements. The pillar will be poured onsite with concrete delivered to the site via concrete trucks from a local batch plant. Poles may be delivered to the staked location or to a designated marshalling yard depending on delivery and contractor availability. If the poles are delivered to a staked site, they are placed on the right-of-way out of the clear zone of any adjacent highways or designed pathways. The poles are typically framed with insulators and hardware on the ground and then lifted and placed in the hole via a bucket truck or a crane depending on the weight of the structure. Once the structures have been erected, conductors are installed by establishing stringing setup areas within the right-of-way. These stringing setup areas are typically located 13