BERLIN — Delmarva Power last week asked the Maryland Public Service Commission to authorize an adjustment in electric delivery rates to bolster the company’s ongoing efforts to maintain safe and reliable service, provide enhanced customer service technology and support the additional resources that were needed to restore service to customers after Hurricane Irene in August. If approved, the proposed $25.2 million request would result in a 5.6 percent increase on a typical Maryland residential customer’s bill, effective July 2012. The monthly bill for a residential Standard Offer Service customer using 1,000 kilowatt hours a month would increase by $7.29 per month, from $129.26 to $136.55. The impact on commercial and industrial customers would vary by usage. “We are working diligently to maintain safe and reliable service and to enhance technology to benefit our customers,” said Gary Stockbridge, Delmarva Power Region President. “We’re replacing and upgrading our infrastructure and reducing potential service interruptions by trimming trees around power lines.” The company invested approximately $200 million in infrastructure enhancements from 2007 through 2011 and plans to spend an additional $344 million through 2016 in order to meet customer growth and maintain a reliable electric system.