Normally people eat chametz until the time on Erev Pesach that one is obligated to stop eating chametz and then people dispose of it and burn the chametz...this year because Erev Pesach is on Shabbos, and one cannot eat matza on Erev Pesach, and we need a way to dispose of our remaining chametz after eating the challa (in whatever form you might have it) but unable to burn it because of Shabbos, it is common for one of those methods being flushing the remaining chametz down the toilet.

The rabbanim of Bet Shemesh, whoever they are - I havent seen a list of the 30 names signed on the letter - issued a psak that people should not dispose of their remaining chametz by flushing it down the toilet on Shabbos, whether it is just the chametz itself or even if the chametz is wrapped in a vessel of some sort such as a bag. In previous years when the situation was similar with Shabbos being Erev Pesach, people flushed things down the toilet and it caused problems with the pipes getting stuffed up and even caused chametz to come back up, and sometimes also into neighbors houses, on Pesach itself. This is therefore a mitzva of disposing the chametz being done by causing damage and even causing people to have chametz present, and it is a mitzva being done via an aveira.

It sounds horrible and disgusting. I dont know why any homeowner would flush bags of chametz down the toilet or drain. I can understand crumbling up bread into small pieces, that seems ok, but big pieces and doing it with bags or other containers seems worse than negligent and a recipe for disaster. Do they really not think it might cause a blockage of the pipes and have a sewage backup over the holiday?

Besides for the damage being caused to everyone in the area, I am not sure there is really a chametz issue. once the food has been sitting in the sewage system it doesnt seem like it retains its status as edible food. And anyway, if I am the neighbor and have someone else's chametz coming up through my pipes, it still doesnt belong to me so I havent violated the prohibition of having chametz on pesach. EVen the fellow who flushed it down was mafkir it and did the annulment of chametz so it is stupid to do this, it is damaging to do this, but I dont think it is a violation of the rules of chametz nor is it causing others to sin.

The rabbonim signed on the letter suggested an alternate solution. They suggested throwing any remaining chametz into the street, into the public thoroughfare. The Municipality has no intention to acquire that chametz and will make all the garbage cans hefker before Shabbos, so chametz can be disposed of in city garbage cans.

It is not uncommon here for people to refuse to dispose of old bread in the garbage cans, even wrapped up, and instead just put the leftover bread (all year round) on top of walls near the garbage cans or on top of the garbage cans. I wonder how they will do this before Pesach rather than putting it in the hefker bins...

If the city if making all the garbage bins hefker, I wonder what they would do if somebody would take ownership of some of these bins and take them home...