His status in haredi circles is legendary, and for years his kashrut seal has appeared on every kind grocery item. Now, you can get tap water with the seal of Moshe Yehuda Leib Landau, the chief rabbi of Bnei Brak.
Though during the year a tiny amount of something non-kosher doesn’t render otherwise kosher food off-limits, on Passover, a principle of assur b’mashehu applies. This means that, strictly speaking, even a small spec of bread renders a huge pot of Passover food hametz.
The question that has bothered some Israeli Orthodox rabbis for years is: Given that much of Israel’s water supply comes from the Sea of Galilee, if a picnicker dropped a sandwich in the lake, wouldn’t that make all of Israel’s drinking water hametz?
To be on the safe side, some Orthodox families fill up huge tanks with water before Passover (the strict rules don’t apply to water that you owned before the festival). This year, the Bnei Brak municipality arranged with Mekorot, the company that pipes Israel’s water, to only receive desalinated sea-water.
And just to make sure that the desalination operation is hametz-free, Landau went to visit ahead of the festival. His aides said they were impressed that the water is pumped from the depths of the Mediterranean — presumably thought to be a hametz-free area. If anyone is reading this from a cruise ship on the Med and recalls dropping a sandwich overboard, please wait until after Passover to post a comment.
A New Passover Tradition: Desalinated Water