NEW : Officials expect the lake to be drained by Friday . Mother says the family has been polygraphed , which is hard but necessary . They are being held in a jail cell for now until they can get out of there and go home. Scent dogs ran around the lake and stopped at the water 's edge .
NEW : Officials expect the lake to be drained by Friday . Mother says the family has been polygraphed , which is hard but necessary . Mother says the girls do n't go to or swim in Meyers Lake . Scent dogs ran around the lake and stopped at the water 's edge .