There are sewer tanks where, when full, an electric sewer pump automatically turns on.

Is it a problem to pour water down the drain (washing hands, flushing the toilet) into such a sewer system?

One is not directly causing the pump to turn on -- it only kicks in if the tank becomes full.


2 Answers 2


Rav Aryeh Leibowitz quotes the Nishmas Shabbos (6:75 - note this teshuva doesn't seem to be the correct address) saying that if the electric sewer pump will only be activated after a few flushes, then it may only be considered a grama since it's a ko'ach sheni. Nonetheless, if you can pour the water out upstairs then it is better to do that, while it may be uncomfortable for a guest in the basement to go upstairs. He also notes that is would be better to wash your hands with the faucet rather than a utensil since using a utensil would be pouring the water directly into the container while just opening the pipe is less direct. He also notes that it's a safek psik reisha which might be considered a davar she'eino miskaven, so there is more room to be lenient. Rav Leibowitz concludes saying that many poskim are lenient with a commercial tank which holds more than one flush, though it's better to use an alternative bathroom if it's not uncomfortable.

  • That's what I heard when a shul renovated recently -- get a commercial system so that no one flush will definitively trigger it.
    – Shalom
    May 26, 2020 at 15:53
  • After doing some research it seems like it is in an addendum to Vol 6 #75. However unable to find the addendum online. May 27, 2020 at 2:32

Rabbi Meir Aaron who operates Halacha.CO who is a Chabad Rabbi, says it is permitted for the following reasons.

1 - It does not turn on specifically after each flush.

2 - Kovod HaBriyos is permitted when the prohibition is Rabinnic in nature.

See here for the entire answer and sources.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .