Northern Wasco Parks and Recreation District says it has been able to source enough liquid chlorine to be open the Northern Wasco Aquatic Center for the next four days on a modified schedule.   Open swims are scheduled Friday from 1 p.m. to 7 p.m., and Saturday, Sunday, and Monday from 10 a.m. to 2 p.m. each day.  The district says the rest of the week is still to be determined, as it hunts for chlorine during the current shortage to be open as much as possible.  Issues at a major chlorine production facility in Longview has led to a liquid chlorine shortage throughout the Northwest.