Narragansett Bay is the cleanest it has been in more than a century  – but the federal government says it’s still not enough. That means customers of the Narragansett Bay Commission pay triple what they did in 2001 because of nearly $600 million worth of water quality improvements over the past 15 years. This week Jim Hummel sits down with the commission’s executive director, who says it’s a delicate balance between clean water and equitable sewer rates.