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

Home

Enterprise Park to Crooked Lake 115 kV Transmission Line March 2012 Environmental Assessment The transmission line will be designed to meet the NESC and the Institute of Electrical and Electronics Engineers standards. The NESC recommends minimum safety standards for clearances over roadways, buildings, signs, light standards, and other facilities. In most instances, the Applicant states that NESC height standards over highways and roadways (20.1-feet minimum clearance) will be exceeded. In some cases, greater clearances are dictated by MnDOT or local county highway permitting. The Applicant has stated it will work with these agencies to meet their clearance requirements. Although the existing standards give recommended clearances over buildings, the Applicant has stated it will not locate transmission lines directly over a building unless it cannot be avoided. Horizontal clearances to buildings, signs, light standards, and other installations are determined by calculating the blowout of the wire, structure deflection, and safe electrical clearance from the line. 4.3. Transmission Line Conductors The single circuit structures will have three single -conductor phase wires (not bundled) and one shield wire. The phase wires will be 795 ACSS 26/7 (Aluminum Conductor Steel Supported with 7 steel core strands and 26 outer aluminum strands). The shield wire will be 0.528 optical ground wire. The average span between structures without underbuild will be 300-400 feet and structure heights will range from 60 to 85 feet. The diameter of wood poles at ground level ranges between 15 and 22 inches. Rectangular laminated poles are buried in steel culverts typically four to six feet in diameter that are filled with crushed rock. Steel poles are mounted on concrete pillar foundations with diameters ranging from four to eight feet in diameter with the pole slightly smaller than the concrete pillar. Structures, pole heights and spans will vary depending upon topography and environmental constraints (such as highway crossings, water crossings, and required angle structures). 4.4. Cleanup and Restoration The HVTL route permit will require the Applicant to restore the ROW following construction. Upon the completion of construction, property owners and interested parties will be contacted by the Applicant to determine the extent of construction damages, if any. Personal property and real estate that may have sustained construction - related damage will be restored or replaced by the Applicant to its pre -construction condition or better. Property owners and other interested parties will again be notified by the Applicant upon the completion of the restoration and cleanup, and will be directed to report any outstanding construction issues that have not been addressed. Once construction cleanup is complete and construction damages have been successfully mitigated, landowners will be sent a final notification advising them of the completion of the Project. 18