Transmission Line Route Evaluation


Allegheny Power


Saltsburg, PA

CEC Services

  • GIS Data Processing
  • Land Feature Mapping
  • Web Application Design and Implementation
  • Document Management

Owner Objective

Allegheny Power was an electric utility company until merging with First Energy in 2011. It owned and operated electric generation facilities and delivered electric services to customers in Virginia, West Virginia, Pennsylvania and Maryland. Allegheny Power proposed a 20-mile 138 KV transmission line between North Washington and their Saltsburg substations.

CEC Approach

CEC performed a transmission line route evaluation (LRE) in support of the siting and certification of the electric transmission line. The purpose of the LRE was to determine a route for the proposed transmission line that best met the project purpose and need while minimizing social, cultural, ecological, and land use impacts.

CEC acquired spatial and non-spatial data from local counties and municipalities, state and federal agencies, private organizations, and other stakeholders. The constraints data included:

  • Urban features (i.e., residences, commercial and industrial sites, mine lands, gas and oil wells, groundwater wells, roads);
  • Cultural and social features (i.e., schools, religious facilities, parks and recreational areas, archaeological and cultural resources);
  • Ecological features (i.e., wetlands, streams, rare species, conservation areas, floodplains, scenic rivers); and
  • Existing and future land use (i.e., agricultural, forested, urban and suburban, commercial/industrial, number of properties traversed).

A Geographic Information System (GIS) (ESRI ArcMap) was used to create a constraint database from existing digital spatial data. Non-digital data sources were georeferenced and digitized within ArcMap and then added to the constraints database. Using the constraints database and the geoprocessing and analytical functions of GIS, CEC created alternate transmission line routes that avoided or minimized impacts to known constraints. CEC joined the client’s engineers in a field reconnaissance of the study area to refine the proposed alternate routes and to identify and verify constraints data. CEC then enumerated and fractionally ranked the constraints data for the alternate routes to identify the routes with the lowest number of constraints overall. The constraints data were then compared for the top-ranked routes to determine which constraints were most significant in the calculation of the rankings. Additional factors considered in the selection of the preferred route included existing land cover and potential future land use. The LRE analysis resulted in the selection of a preferred transmission line route.