Location; South Charleston, WV | Market Served; Wastewater | Key Services; Electrical Engineering

 

Keystone Engineering Group is designing the replacement of the primary distribution system servicing the South Charleston Sewage
Treatment Plant. The treatment plant is jointly owned and operated by the South Charleston Sanitary Board, a municipal utility, and
Dow Chemical, a privately owned industrial corporation. The Design phase of this project kicked off in January 2018. The power
distribution system, consists of two 46kV overhead services to two separate substations at opposite sides of the plant, feeding 2300V to
five distribution substations located around the plant. The proposed upgrade replaces the existing electrical system between the 46kV
equipment down to the existing 480V switchboards and MCCs, while keeping the budget within manageable limits.

The conceptual design includes the installation of a 46kV to 13.8kV substation transformers and switchgear at each of the substations,
with 13.8kV feeders to a new dual fed 13.8kV to 480V substation feeding a new outdoor low voltage main-tie-main switchgear with
automatic throw over control. The 480V feeders from the switchgear will directly feed the plant’s 480V switchboards and MCCs,
bypassing the 2300V distribution substations which are scheduled for demolition. Keystone was hired by Thrasher Engineering, the
engineer of record for this project, to resolve a budgeting problem that had risen between the Owners of the plant. An original budget
of $7M was proposed at the conceptual design phase of the project, which escalated to $14M upon receiving preliminary cost estimates
from contractors. Keystone was hired to evaluate the construction scope, propose cost saving measures, and determine if the total
project can be delivered for the original $7M budget with scope of work acceptable to both DOW and the City of South Charleston.

Demolition of the old equipment and the installation of new equipment requires arrangement of the construction sequence to keep the
facility in operation with state mandated backup power and due consideration for limiting construction costs from temporary power
systems and generators.