Tribal scientists and community members are testing wells, solving plumbing problems and delivering clean water to their neighbors. — Emery Three Irons, a Crow tribal member, stood in tall, lush grass one day in late May, contemplating a cream-colored house. After 20 minutes of reflection, he approached two 5-year-olds standing on the front steps, eating popsicles and playing with a puppy. “Is your grandpa awake?” he asked them, his…