Walters, Nantahala, and Thorpe Secondary Containment Design
Duke Energy (Duke) was exploring the option to add and/or update secondary containment to oil containing equipment in the switchyards at the Thorpe, Nantahala, and Walters Hydro plants to eliminate risks of oil spills into the rivers. Duke required engineering services for the best-fit design of the secondary containment systems.
Kleinschmidt facilitated kickoff meetings at each site to review the design alternatives and select the Duke preferred alternatives and desired modifications. A feasibility study was completed, and three primary options subsequently presented to Duke were a concrete containment option along with two types of membrane containment options. Prior to proceeding with the detail design of the switchyard containment, Kleinschmidt prepared simple preliminary plan layout drawings of each substation showing the outline of the containment areas and the locations of the water discharge point (i.e.: gravity drain or sump pump). Following approval by Duke of the preliminary layouts, we proceeded with the detail design of each containment system. Ground Penetrating Radar (GPR) work is being completed to assist in locating utilities and a site topographic survey will be conducted at each location. Kleinschmidt submitted a 60 percent design package for review and will complete the final design package including drawings and instructions for installation of secondary containment. We will provide permitting, bidding assistance, and construction support services following final design We will also provide record drawing updates to Duke Energy’s existing drawings to reflect the as-built configuration of the switchyards after construction is complete.
Kleinschmidt provided services in a manner to fully integrate client input and preferences, finding ways to achieve design goals and have a constructible product. The design also included maintenance reducing improvements. Safety was a significant consideration during the planning and design process as there will be construction and maintenance activities during power generation. The design schedule was shortened to allow for construction activity during the same year as design being completed.