Just when David Miller figured he’d ease up on his career gas pedal and coast into retirement, he finds himself more invigorated than ever about his business, Miller’s Septic Service in Mauston, Wis.The reason? Jason Graves, the boyfriend of his 22-year-old daughter, Kristin, is joining the company — and perhaps eventually will take over. While there’s no guarantee the latter will happen, Miller nonetheless is happy about the unexpected chance to pass on the lessons he’s learned after 25 years in the business and, at the same time, view the industry through the prism of Graves’ more progressive ideas.“It’s an
