Ahead of a required application to state regulators expected by the end of the year, contractor PSEG has identified 10 potential routes for transmission lines regional electrical grid operator PJM says are needed amid power plant retirements and growing demand as part of the controversial Maryland Piedmont Reliability Project. While the exact path is to be determined, the high-voltage lines would stretch approximately 70 miles through farms, parks, neighborhoods, wetlands and forests in Baltimore, Carroll and Frederick counties, from existing transmission lines northeast of Parkton to an existing substation southwest of Frederick. See where each alternative (lettered A-J) would go in the interactive below.