Midway to Waterton 345-kV Transmission

Location: Colorado

Client: Xcel Energy

Completion Date: 2010

Xcel Energy selected Burns & McDonnell as its engineer-procure-construct (EPC) contractor for its Midway, Colo., to Waterton, Colo., 345-kV transmission line project. Located just south of Denver, this project consists of 9 miles of double-circuit, 345-kV transmission line with self-supporting, weathering steel structures between Waterton and Daniels Park, Colo. At Daniels Park, the new transmission line segment attaches to another line that continues to Midway. Burns & McDonnell will construct new 345-kV/230-kV additions to existing 230-kV facilities at Midway and Waterton.

  • Transmission design
  • Substation design
  • Procurement
  • Construction management

The Waterton Substation to Midway Substation scope includes a new 345-kV line terminal, 345-kV power circuit breaker, 345-kV/230-kV, 560 MVA autotransformer, new control building with protection and controls, replacement of two 230-kV/115-kV autotransformers with 280 MVA units, expansion of the 230-kV breaker-and-a-half configuration, and replacement of 115-kV power circuit breakers due to increased fault currents.

The Midway Substation to Waterton Substation scope includes a 345-kV line terminal, 345-kV power circuit breaker, 345-kV/230-kV, 560 MVA autotransformer, new control building with protection and controls, and modification of the existing 230-kV breaker-and-a-half arrangement.

Burns & McDonnell will design transmission modeling with PLS-CADD software and provide geotechnical investigating and recommendation, aerial and ground surveying, establishing design criteria for environmental loads and clearances, conformance with National Electric Safety Code and Xcel Energy requirements, and pole-for-pole replacement of existing 230-kV line where feasible. Burns & McDonnell will also prepare detailed load and design drawings, conductor and shield wire detail and sag charts, hardware and assemblies drawings, vibration and spacer analysis, grounding drawings, foundation design, and permitting support.

Substation design will include:

  • Civil design — grading and erosion control, landscaping, foundations and
    oil containment
  • Physical design — rigid bus grounding, lightning protection, raceway lighting and station layout
  • Electrical protection and control — AC/DC systems, schematics, cable schedules, panel layouts, control building layout, relay setting, one-line diagrams and wire drawings

Burns & McDonnell will also be responsible for preparing a design guide and procuring a topographical survey, geotechnical investigations, soil-resistivity data, regulatory and construction permits (except route permit), and transmission and substation equipment and materials, while preparing the necessary drawings and supporting Xcel Energy in its Certificate of Public Convenience process and application. Burns & McDonnell will work closely with construction subcontractors to achieve erosion and sediment control, flora and fauna requirements and restrictions, and additional permit compliance. For overall project support, Burns & McDonnell will prepare a detailed schedule, project budgets, cost reports and cash flow reports. The project scope also includes outage coordination, testing preparation and management, and commissioning planning.