Nearly a month after being closed to the public due to an infestation of blue-green algae, Stevens Pond will close for the remainder of the season, North Andover Youth and Recreation Services officials announced. Recreation officials called the decision unfortunate, but necessary, due to the lack of rain this summer that would have otherwise helped break up the infestation by agitating the water surface. The algae can produce toxins that can be dangerous to humans and animals. Reimbursements were issued Aug. 8 to residents who purchased a season pass to the pond and to those who purchased Session 2 swimming lessons. Anyone who has not received a reimbursement yet should call 978-682-9000.