McCormick Taylor supported Delmarva Power & Light (DPL) with the rebuild of their existing 69 kV line and with the installation of a new 138 kV transmission line from Piney Grove Substation in Wicomico County, MD to the Wattsville Substation in Accomack County, VA.



Stretching nearly 30 miles in length—21 miles in Maryland and 9 miles in Virginia—the Piney Grove to Wattsville Transmission Line Rebuild project required licensing from the Virginia State Corporate Commission and a Certificate of Public Convenience and Necessity (CPCN) from the Maryland Public Service Commission (PSC).


The project was challenging from a transmission engineering and environmental permitting perspective as it consisted of the rebuild of an existing 69 kV transmission line along with the installation of a new 138 kV transmission line. Because of these variables, the CPCN and Alternative Routing Analysis (ARA) required extensive coordination between the different disciplines involved to develop the project alternative and design that met the needs of the project, while also meeting the requirements of the CPCN process.


As part of this coordination, McCormick Taylor worked with DPL to implement and utilize electronic Environmental Review Documents (eERDs), which helped facilitate the streamlined review process with the agencies for the project. Providing a permittable, constructible design for the project allowed for the safe and reliable transmission of electricity to the lower Delmarva peninsula. The approach and lessons learned, including the development of the streamlined review process with the agencies, can be applied to future projects in the region and industry.

photo 2 transmission tower caisson drilling
photo 3 transmission line installation using helicopter


McCormick Taylor was responsible for preparing the Environmental Review Documents (ERD) in support of the CPCN application and Virginia State Corporate Commission submission, preparing the Section 404 permit applications and mitigation plan, and conducting environmental compliance inspections during construction. In support of these efforts, this project also required McCormick Taylor to conduct several environmental studies and extensive coordination with federal and state regulatory agencies, including the Army Corps of Engineers – Baltimore and Norfolk Districts, the Maryland Department of the Environment, the Maryland Department of Natural Resources (DNR), and the Chesapeake Bay Critical Area. The studies included, but were not limited to: Alternative Route Analysis, wetland delineation, Threatened and Endangered Species Surveys, Joint Permit Application(s), Class I cultural Resource Survey, and Visual Quality analysis.


The project crossed several unique and valuable environmental resources, including the wild and scenic Pocomoke River, Chesapeake Bay Critical Areas, tidal wetlands, and threatened and endangered species’ habitats. The presence of these resources within and adjacent to the project area required extensive coordination with the regulatory agencies, including the DNR. McCormick Taylor, in conjunction with DPL, worked extensively with the DNR to ensure that the most feasible route was selected for the project to minimize or avoid impacts to the valuable resources in the area.

photo 5 completed project 2


The project spanned substantial non-tidal and tidal wetlands including the Pocomoke River, but construction methods minimized environmental impacts to these sensitive locations.


In addition to the elements of the project directly associated with the design and construction of the transmission line, McCormick Taylor worked with DPL to design the Wetland Mitigation site which was required as a result of the wetland impacts associated with the project. McCormick Taylor developed the wetland mitigation design after a comprehensive mitigation site search. Our engineers worked with our scientists to develop the proposed design, which was approved by the agencies and is currently under construction. McCormick Taylor is currently providing designated specialist construction oversight support during the construction project to provide design guidance.



2020 Honor Award, ACEC/MD Engineering Excellence Awards

2020 National Recognition Award, ACEC National

photo 6 completed project 3