Amherst DPW workers are testing the water of the newly filled War Memorial Pool to make sure it's OK to re-open for the first time in three years.  Tests are being done on the pool's new filtration system to make sure it's working properly.  A decision on whether to open the pool following major repairs is expected Friday.  Town Manager John Musante says in the meantime, the town's other outdoor pool at the Mill River Recreational Area, is already open for the season.