The New Croton Reservoir supplies much of New York City's tap water, and people are allowed to — and do — go out on boats and fish. I'd venture a guess that almost every Saturday and Sunday, a piece of bread falls into the water.

I don't know how long it takes for the water to reach New York, but strongly suspect that the water at the tap in New York is connected by water to the reservoir. (This last suspicion is amplified by the fact that the water travels to New York under gravity alone. For it to do so implies that there's no "break" in the water: any break would be filled by the water propelled by gravity.)

Even a small amount of chametz that gets mixed into water on Pesach makes the water chametz.

I know some New Yorkers do not drink (or cook with) water that comes from the tap on Pesach, but most are not so stringent. Why aren't they? What heter is there to use the water? (Sources, please, if possible.)

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    Firstly, there would be no end. Which water in the world would be permissible? And how can you eat fish that sat in that water? Or carrots that may have been washed with that water... Or Matzo that was baked with that water.
    – yydl
    Commented Mar 29, 2011 at 4:36
  • 2
    And finally, "Even a small amount of chametz": How small is small. Does a piece of bread in an ocean make the entire ocean Chametz?
    – yydl
    Commented Mar 29, 2011 at 4:37
  • 1
    Regarding your second point, R'yydl, maybe so: I don't know how the filtering works. If that is in fact the case, then perhaps that answers my question. (Though, I suppose, if it takes less than a week for the water to travel from Croton to New York, then an interruption in the flow wouldn't help any, as New Yorkers are still getting chametz water). Anyone know?
    – msh210
    Commented Mar 29, 2011 at 5:50
  • 2
    The Chometz is most likely eaten up by the fish way before it gets to your house Commented Mar 29, 2011 at 12:22
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    R'Gershon Gold, all of it will be? Is that a halacha-based "most likely"? Remember that chametz is not batel.
    – msh210
    Commented Mar 29, 2011 at 15:27

4 Answers 4


Hacham Ovadia Yosef discusses this issue in Yabia Omer Helek 7 Siman 44 in terms of the kinneret, which supplies water for most of israel. Kibbutzim along the coast are KNOWN for dumping hametz into the water. He answers that hametz dumped before pesach is nullified in 60. During pesach, he applies the concept of "tzonen bitzonen". Since the hametz and water were both cold (I.e. They weren't cooked together) the flavor of the chametz doesn't spread to all the water, and as long as you're not drinking ACTUAL hametz, there's no problem with the water. He concludes by saying that it's best to use pre-filtered water, but if not, the water is not assur.

  • But isn't it kavush?
    – Double AA
    Commented Sep 9, 2012 at 14:26
  • Some discussion on kavush from the OU
    – Zachariah
    Commented Dec 11, 2012 at 18:31
  • @BaalShemotTovot But how can you be sure that you aren't drinking actual chametz in it? I know there's a very small chance--but what is the halachic reason you're allowed to take that chance?
    – SAH
    Commented Feb 16, 2015 at 10:02

R' Shneur Zalman of Liadi writes (Orach Chaim 467:48):

מי שרוצה לשאוב בפסח מבארות של נכרים או מבארות של ישראל שלא נזהר בהן מחמץ כל השנה, טוב שיסנן המים בבגד נקי בכל פעם ששואב. אבל מעיקר הדין אין מחזיקין איסור מספק.

"One who wants to draw water on Pesach from wells owned by non-Jews, or by Jews but with which they weren't careful to keep chametz away all year - it is best to strain the water through a clean cloth every time he draws water. However, according to the letter of the law, [this is not necessary, because] we don't assume out of doubt that there was something prohibited there."

There is indeed a widespread practice to use new sink aerators for Pesach, or at least to cover the sink spout with cheesecloth or something similar. I believe the main reason for this is that it's likely to have absorbed chametz during the year from dishes being washed in hot water or the like; but according to this, that would also take care of any problems of chametz in the water.

  • 1
    Thanks for the citation. I wonder whether the same can be said for Croton, where it may be beyond לא נזהר בהן מחמץ and in the category of קרוב לודאי. (That "may" indicates a conjecture.) Does anyone have any other sources that agree with the Rav (especially more modern ones that discuss modern reservoirs)?
    – msh210
    Commented Mar 29, 2011 at 15:31

Rabbi Shlomo Zalman Auerbach ruled that while yes, we say "chametz is not nullified even 1/1000", but a few pieces of bread in the ocean are so far past the mark that they become nullified. So somewhere between one-in-a-thousand and one-in-a-quintillion (approximate volume of the Mediterranean in gallons).

  • 2
    A ceratin well-known posek (unfortunately I forget who) put it in the following terms: "A משהו also has a shiur!"
    – Dave
    Commented Mar 29, 2011 at 13:42
  • R'Shalom, do you have a citation, by any chance, please?
    – msh210
    Commented Mar 29, 2011 at 15:28
  • @msh210, afraid I received it as Torah Sheb'al Peh. It's probably in writing someplace.
    – Shalom
    Commented Mar 29, 2011 at 15:38
  • 2
    I've heard (orally) the remark that Dave mentioned attributed to Reb Chaim Ozer of Vilna. Commented Mar 29, 2011 at 16:08
  • Where do you get your estimate of one gallon of bread per Mediterranean? And which type of gallon are we talking about? en.wikipedia.org/wiki/Gallon (See Dave's comment for a justification for these questions.)
    – WAF
    Commented Apr 1, 2011 at 1:27

ialcut iosef brings the case of people throwing hames on the kineret before pesah, in practice one could say he says the same as harav auerbach, but in principle he says that hames before pesah in batel beshishim

now the question would still be pertinent if this happens during pesah itself

so if this is a hidush from harav auerbach I would say safek deoraita lehumra

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