Image courtesy Prince of Petworth If the smell of sewage on the 800 block of Kennedy St. NW is really as bad as residents have said it is, it’s a wonder it only started making headlines this week. NBCWashington.com picked up the story after a nearby resident wrote to Prince of Petworth looking for answers. Sewage has apparently been running down the block, the smell seeping into homes and businesses, since January, the result…