Commonwealth Associates, Inc.

SIGNIFICANT PROJECTS

Commonwealth Associates, Inc. offers consulting, engineering, and design services for power delivery projects throughout the U.S., as well as TRANSMISSION 2000® software for the analysis and planning of electric utility transmission systems.

TRANSMISSION LINE DESIGN

Project: Swan-Tyee Intertie
Client: Southeast Alaska Power Authority

In 2007, Commonwealth was selected by the project’s owner, Southeast Alaska Power Authority (SEAPA), to provide project management services for the Swan-Tyee Intertie 138 kV transmission line and the associated substation modifications. The Swan-Tyee Intertie is a 57-mile tubular steel transmission line that interconnects two remote hydro sites in southeast Alaska. The geography consists of mountainous, timbered terrain. The remoteness of the project required all personnel, equipment, and material to be transported by barge and helicopter. The construction crews were fed and housed at remote floating camps serviced via boats and float planes. The project includes 283 structures and includes three major overhead water crossings: Shrimp Bay (2,585 feet), Behm Canal (5,887 feet), and Eagle Bay (6,890 feet). Two types of conductor were used: 37#8 Alumoweld in the higher elevations and for long spans and 397.5 kcmil “Lark” in the lower elevations.

Commonwealth, as project manager, was responsible for overseeing, coordinating, and reporting the progress of the multiple entities involved with the project, which included the line contractor, substation contractor, clearing contractor, U.S. Forest Service, engineer, environmental monitor, construction manager, inspectors, hydro operation personnel, and material suppliers. Within 20 months of Commonwealth’s selection as project manager the Swan-Tyee Intertie project has come to fruition ahead of schedule and under budget.
Project: Roseland-Bushkill 340 kV/500 kV Project
Client: Public Service Electric & Gas (PSE&G)

This project involves designing a new 45-mile double-circuit 230 kV/500 kV structure transmission line to replace an existing 230 kV transmission line on a narrow 150-foot-wide right-of-way. A portion of this line has to remain energized during construction in order to keep a substation fed from two sources. The remaining line will be constructed in a way that will allow the re-energization of the line in a 14-hour turn-around timeframe. Commonwealth assisted PSE&G with permitting, the design through the Delaware Water Gap area, crossing of existing transmission lines, and interconnections to a new 500 kV switching station. Commonwealth was also involved with the alternative route analysis and the preferred route evaluation. A feasibility report and cost estimates were prepared initially for the preferred route and then the design began. Commonwealth also assisted in the permitting documentation phase. The final deliverables will be a construction package for the entire line and support by Commonwealth during construction. The structures are tubular steel poles, sometimes multi-legged design. The 500 kV circuit consists of four-bundle 1590 kcmil “Falcon” ACSR. The heights of the structure were required to be less than 200 feet. Commonwealth also completed the electrical effects analysis for PSE&G.
Project: Southern Loop 345 kV Project
Client: Vermont Electric

This project is a new 345 kV H-frame design approximately 54 miles in length in mountainous terrain in Vermont for the purpose of reinforcing the existing transmission grid system. The new 345 kV transmission line is paralleling an existing 345 kV line. The new line has a loop interconnecting into a new substation. The new line was designed to match as both existing structure location and type of structure as closely as possible as well as to avoid environmentally sensitive areas. The design criteria of the old line had to be recreated in order to match the old code design to the current code design, hence match the existing 345 kV design. New steel poles were designed for use in selected areas. Also, existing Vermont River crossing structures were analyzed as part of this project. Modifications to the existing guying had to occur so as not to interfere with the new parallel line. The conductor was two-bundle 954 kcmil “Rail” ACSR. PLS-CADD was used for the routing, permitting and design phases of this project.
Project: Wabash Blissfield Ethanol Plant 138 (115) kV Transmission Line
Client: Wabash Valley Electric Cooperative

In 2006, Commonwealth designed a new wood 138 kV transmission line 4.5 miles in length. Private easements were purchased for right-of-way and tree trimming. In addition, routing and permitting services were rendered as part of the total work. Commonwealth’s responsibility for the project included the services above as well as project management of the overall schedule; construction bidding and award; material bidding, ordering and expediting; and construction field audits (construction management) of the construction. Work was performed in the Jackson, Michigan, office with multiple on-site visits and meetings to coordinate construction management and design efforts. The total design costs were approximately $175,000, with the overall project costs at $1,250,000. Survey subcontractors were contracted and managed as part of the project. The scope of the work included a digital terrain model for design and staking of the transmission structures for construction. The construction of the line was completed 2 weeks prior to the in-service set forth by the client.

SUBSTATION DESIGN

Project: Auburn St. and Bridgewater 345 kV Substation BPS Upgrades
Client: National Grid

Commonwealth provided preliminary engineering services to National Grid for upgrading two 345/115 kV substations to comply with NPCC Bulk Power System (BPS) standards. Station improvements include the following:
- Auburn St. 345-115 kV Substation
  Approximately 90% of the Auburn St. substation will be removed from service and demolished over a 24-month construction and cutover period. Construction will be sequenced in such a manner that outages are minimized and grid reliability maintained. The final substation is comprised of eight 345 kV gas circuit breakers, two autotransformer banks and sixteen 115 kV gas circuit breakers, new control house, all new control/protection systems, new raceway systems, 115 kV underground cables and along with some 115 kV transmission structures.
- Bridgewater 345-115 kV Substation
  The majority of the work at Bridgewater involves the construction of a new control house with all new controls/protection to conform to current NPCC BPS standards. The control house will be constructed and fully outfitted with all instrumentation before commencement of cutover activities. The station comprises four 345 kV gas circuit breakers, two autotransformer banks, and fourteen 115 kV gas circuit breakers.
Project: Relocation of NIPSCo Electric Transmission Lines for Airport Expansion
Client: Gary/Chicago International Airport

As part of a runway expansion project, it was necessary to relocate approximately 3,000 feet of 345 kV, 138 kV, and 34.5 kV overhead transmission line owned by Northern Indiana Public Service Company. The project tasks included evaluating the underground relocation of the overhead circuits using 3000 kcmil copper XLPE 345 kV, 2500 kcmil copper XLPE 138 kV, and 1000 kcmil aluminum XLPE 69 kV cables. After evaluation of several options, the selected economic option required the design of a 345/138 kV substation, two 138 kV underground transmission lines, and one 34.5 kV underground line. To provide the necessary capacity, the lines were designed with 3156 kcmil aluminum XPLE 138 kV cable and 1000 kcmil copper EPR 35 kV cable.
Project: Haddam 345/115/23 kV Substation
Client: Northeast Utilities

Commonwealth provided engineering design, material bid packages, and construction bid packages for rebuilding a bulk power substation. The substation consisted of a new 345 kV switchyard for a tapped line; autotransformer; 115 kV breaker and a half switchyard for five lines, 115 kV capacitor bank, two 115/ 23 kV transformers, and two 23 kV switchgear housings, new control house, ac and dc auxiliary systems, protection/ relay/control systems, SCADA and a DFR. One of the more interesting challenges at Haddam was determining the best way to minimize outages as the new substation was constructed by the old one. The basic plan required continued operation of the 34.5 kV distribution system during the construction period. To accomplish this, phased construction and cutover activities were developed to support operational needs:
- First, a portion of the new 115 kV and 34.5 kV station was constructed and then interconnected with the existing 115 kV. The interconnection also required some temporary protection circuitry to ensure reliability of the system. Interconnecting the two stations allowed swing of three 115 kV lines from the old station to the new. Also during this period, staged cutovers of 34.5 kV cable circuits occurred.
- Second, after reconfiguring the 34.5 kV and 115 kV circuits, it was possible to remove the old 115 kV and 34.5 kV facilities, making room for the new. Existing foundations, duct banks, grounding conduits, equipment and control house were all removed in this phase
- Third, within the area now cleared, the 115 kV station was finished, the new autotransformer bank installed, and the 345 kV yard constructed. The 345 kV yard was strategically developed to allow tapping of an existing overhead 345 kV line, including consideration for further expansion into a 4-breaker ring bus with a second autotransformer bank.

ELECTRICAL SYSTEMS STUDIES

Project: Geauga County EMF Calculations and Public Meetings
Client: FirstEnergy Service Company

Commonwealth calculated electrical and magnetic fields and radio noise for the proposed Geauga County double-circuit 138 kV transmission line. Our staff also participated in public meetings to answer questions posed by the attendees.
Project: Transmission Impact Study
Client: East Kentucky Power Cooperative

Commonwealth conducted a transmission impact study for the connection of a large load near Dover, Kentucky. The work included steady-state voltage, short circuit and transient stability analyses.
Project: Arc Flash Hazard Study
Client: New Covert Generating Company

Commonwealth performed an arc flash hazard analysis of the Covert plant auxiliary power system. Arc flash calculations were performed in accordance with IEEE Standard 1584 using ETAP software. We provided a report of our findings and arc flash labels to the client.
Project: Assessment of Kentucky’s Transmission System Vulnerability to Electrical Disturbances
Client: Kentucky Public Service Commission

Commonwealth conducted a transmission power flow analysis to identify various scenarios that could stress the electrical system of Kentucky. The study was performed using Commonwealth’s proprietary Cascade Analysis program to test the system’s vulnerability. The scenarios included electrical disturbances to the power system both inside and outside Kentucky.

LAND ACQUISITION

Project: Runway Safety Compliance Project
Client: Southwest Michigan Regional Airport

Commonwealth land specialists are providing appraisal management, interviews, negotiation, relocation, settlement, closing, and other services to enable the Southwest Michigan Regional Airport in Benton Harbor, Michigan, to acquire properties for expansion of the airport and provide relocation services for more than 225 residents being displaced. During the first phase of this multi-year project, Commonwealth conducted interviews with owners and tenants to explain the acquisition process and federal relocation procedures. Property value appraisals were prepared by independent appraisal firms and reviewed by Commonwealth for conformance to federal and state standards. Several agencies, vendors, realtors, and developers are participating with Commonwealth to provide assistance and supplement the available housing stock. Commonwealth is coordinating with various agencies such as MSHDA and Habitat for Humanity to provide assistance and advice on financing matters.

Commonwealth will prepare purchase offers and negotiate agreements. Additionally, eligible relocation benefits will be explained to the residents being displaced. If necessary, Commonwealth will assist the airport with condemnation and eviction proceedings. After acquisition of properties, Commonwealth will oversee any salvage operations and the demolition or moving of the buildings. Commonwealth will manage the property until it is turned over to the airport, along with a complete set of files for the airport’s records.
Project: Runway 32 Expansion
Client: Muskegon County Airport

Over a 6-month period, Commonwealth provided land acquisition expertise to assemble and manage a team working with 23 landowners in the fee simple acquisition of approximately 15 acres of land needed for lengthening Runway 32 at the Muskegon County Airport. Commonwealth managed interviews and negotiations with the landowners, secured property appraisals, prepared relocation benefit determinations, obtained environmental surveys for each property, assisted in closings, and oversaw the demolition and removal of houses and other buildings. Commonwealth also managed a subcontractor conducting hazardous material surveys and inspections for lead and asbestos in the buildings on the properties. Throughout the project, Commonwealth coordinated activities with the engineering firm designing the airport expansion and worked to meet the special regulatory requirements of Muskegon County and the Federal Aviation Administration.
Project: Potomac-Appalachian Transmission Highline (PATH) Project
Client: The Louis Berger Group/PATH West Virginia Transmission Company

Commonwealth provided land services for the Potomac-Appalachian Transmission Highline (PATH) project involving 250 miles of transmission line from Putnam County, West Virginia, to Kemptown, Maryland. The client needed a landownership database and a copy of the deed of record by which each owner took title for more than 3,000 parcels. Our GIS staff processed the digital imagery and created a GIS shapefile of the parcels within a 2,200-foot corridor along the preferred route within West Virginia and Virginia. This boundary information was obtained from tax assessors’ offices. Where digital information was not available, the information was collected at the individual counties in paper format and scanned and digitized in ArcGIS. At the initial stage, the property owner information from the tax records was linked to the shapefile via a landownership database. These shape files were then utilized to create maps to aid the land agents in pulling last deed-of-record documents. The landownership database was then augmented using this more detailed ownership information, and the property lines in the shapefile were adjusted where necessary. Working with the primary siting consultant, this information was incorporated onto a secure SharePoint website that the client and other consultants could access. Commonwealth completed this assignment within a 45-day period.
Project Name: Susquehanna-Roseland 500 kV Project
Client: Public Service Electric & Gas (PSE&G)

Commonwealth was involved in securing permission to enter, access road options, and easement negotiations for 570 parcels along the transmission line route. Our field agents entered data and contact records from the field using Commonwealth’s LadStat database system.