The Vermont Public Utility Commission on May 15 adopted a hearing officer’s recommendations that the commission approve Green Mountain Power’s (GMP) Websterville substation project in the Town of Barre, Vt., and issue a certificate of public good (CPG), subject to conditions.
As noted in the final order, the project entails the:
- Demolition and removal of the existing Websterville substation and a neighboring residence acquired by GMP
- Construction of a new substation on the existing parcel, as well as the neighboring parcel acquired by GMP
- Installation and use of temporary substation facilities during the course of demolition and construction
The new Websterville substation will include:
- A new substation fence, about eight feet tall, that will create a fenced-in yard of about 102 feet by 188 feet
- New equipment foundations, a new control house foundation, a new ground grid, a new below-grade trench, and new conduit systems
- Three temporary 45-foot-tall transmission poles to facilitate site work, two new 50-foot utility poles, and one new 55-foot transmission pole to allow for interconnection of the transmission lines with the substation
- A new 34.5-kV transmission steel structure with associated insulators and lightning arresters, six 38-kV vacuum circuit breakers with associated disconnects and bypass switches, two 34.5-kV 3600kVAR capacitor banks, six 34.5-kV potential transformers with associated fusing, and one 25kVA station service transformer with associated fusing. The 34.5-kV bus will be fed by three overhead transmission lines entering the substation on the north side
- A new 12.47-kV distribution steel structure with associated insulators and lightning arresters, three 15-kV vacuum circuit breakers with associated disconnects, nine 438Amp voltage transformers, six 12-kV potential transformers with associated fusing, three gang-operated load break switches, and one 25kVA station service transformer with associated fusing. Three 12.47-kV distribution circuits will exit the substation on the south side
- A new 15/28MVA 34.5-kV to 12.47-kV power transformer with oil containment and associated station class lightning arresters
- A new control house. The control building will house the relay protection and control panels, supervisory control and data access (SCADA) equipment, fiber optic communication, and other miscellaneous control devices. A DC battery system and AC/DC distribution panels will also be installed in the control building. Fiber optic communication between the GMP control center and the substation will be used for SCADA monitoring and control, voice grade communication, and engineering access for retrieval of fault records from local microprocessor relays. A GPS antenna will be mounted to the roof of the control building
- Five new substation light poles for maintenance and emergency activities in the substation yard
- A substation security system
- An animal deterrent fence system around the distribution bus
The final order added that in response to public comments made by the Town of Barre Planning Commission, GMP has stated that it will restrict its construction activities as such:
- GMP will restrict “heavy construction activities” to the hours between 7 a.m., and 5 p.m., Monday through Friday; between 8 a.m., and 5 p.m., on Saturdays; and no construction activities will occur on Sundays or state or federal holidays, except if construction activities must be performed during required outages needed to maintain system reliability
The final order noted that the project will not unduly interfere with the orderly development of the region, with due consideration having been given to the recommendations of the municipal and regional planning commissions, the recommendations of the municipal legislative bodies, and the land conservation measures contained in the plan of any affected municipality.
The hearing examiner recommended that the commission include a condition in the CPG requiring that GMP merge the two parcels during construction or promptly after construction completion.
The final order also noted that the project will meet the need for present and future demand for service, which could not otherwise be provided in a more cost-effective manner through energy conservation programs and measures, as well as energy efficiency and load management measures.
The project is needed to:
- Provide feeder backup to the Barre South #37 and Graniteville #35 substations, which will enhance reliability for customers in the Barre area
- Replace aged and obsolete equipment and infrastructure
- Improve clearances and worker safety at the substation
The final order added that the project will also provide future load-serving capability, increased distributed generation interconnection capacity, and improved system strength. Noting that the project will not have an adverse effect on system stability and reliability, the final order noted that the new substation will have a larger transformer and will be equipped with microprocessor-based relaying that captures event reports for fault location and circuit analysis.
Discussing aesthetic impacts, the final order said that GMP has proposed a landscape mitigation plan to minimize the views of the substation and, in part, has relied on the mitigation plan to support its conclusion that the project’s effect on aesthetics will not be unduly adverse. No party has objected to, or suggested any revisions to, the proposed landscape mitigation plan. The final order also said that the project will not have an undue adverse effect on any endangered species or critical wildlife habitat because there are no endangered species or necessary wildlife within the project area.
Among other things, the final order noted that GMP has entered into a memorandum of understanding (MOU) with the Vermont Agency of Natural Resources, which includes proposed CPG conditions regarding best management practices for penta-poles, sampling of retired equipment to ensure equipment is handled and disposed of properly, demolition and proper disposal of demolition wastes and debris, as well as site management and remediation. The hearing examiner recommended that the commission incorporate the conditions in the MOU in any CPG issued for the project, the final order said.