I received this via e-mail from a source that claims it came from R. Zechariah Gelley of the Breuers community:
ANNOUNCEMENT BY THE RABBINATE
As you most probably have heard, a Sha’aloh has recently been raised about the water in New York City. Initial reports indicated that this problem did not affect water in Manhattan. However, recent information indicates that water in Manhattan shares the same problem as the water in Brooklyn. At this time there still remain gaps in the information available – information that could affect the Heter or Issur of the water.
In the meantime, the Rabbinate is recommending that all drinking water (including ice cubes, tea, coffee, etc.) and cooking water be filtered either through the use of a water filter that can be attached to the faucet or some other device, or by using bottled water that has been filtered.
Before Shabbos one should prepare a sufficient amount of filtered water for use on Shabbos.
Water for rinsing or washing food or dishes need not be filtered. Also water for rinsing one's mouth need not be filtered.
As more information becomes available, this recommendation might change.
10 Tamuz 5764
June 29, ‘04