Question
Can I use this new kind of pump on Shabbos. When I flush the toilet the water then goes to the pump and then the pump activates to remove the waste. Would this be ’Grama of Melacha’ or something like that?
Answer
Shalom,
Thank you for your question. Unfortunately the information I gained from the website of Liberty Pumps, toilet pumps, did not provide the technical information needed to answer your question. The issue (as you point out in your question) is one of how directly the action of flushing is to the turning on of the pump and macerating mechanism. It could be that the pump and other motorized actions only turn on after the waste is flushed down a pipe, and therefore it may be considered as a secondary action. This would be similar to the permission for a person to pour water in their courtyard even though it will run out (afterwards) to the public thoroughfare (See Shulchan Aruch, 357,1 and the Mishna Brurah 1 ibid). This is the basis for using a sink even though the pipe takes the water out to the garden (See Shmirat Shabbat KeHilchatah 12, 18).
On the other hand, it may be that the unit is built in such a way that the act of flushing it itself turns on the motor directly. Of course, in such a case it would be problematic to use such a toilet on Shabbat. [Though there may be room to allow flushing such a toilet with a "shinui" (= a change in the normal way) in cases of embarrassment or hygienic concerns. This could be based on the concept of "kavod ha'briot", the honor of humanity. This leniency would have to be applied on a case by case situation, depending on whether other people use the same toilet; if it is close to end of Shabbat and one could wait to flush the toilet; if someone has a stomach virus etc etc.]
The ruling on this question will also involve another major issue, which is what is the halachic ruling about electricity in general. Although all agree that the use of electricity on Shabbat is totally forbidden, there is an argument as to whether it is forbidden by a Torah prohibition or a Rabbinic one. If the prohibition is Rabbinic there will be more room to rule leniently.
May I suggest that you turn your question to Machon Zomet (http://www.zomet.org.il/eng/). They are experts in questions of halacha and modern appliances. They have created a toilet pump that is totally permitted on Shabbat (search on their home page "Sump Pump"). I am sure that they will be able, with their great technical knowledge, to give you a clearer ruling than I can.
Blessings.
