The rabbi issued a halachic ruling explaining that the using the tap directly turns on an electrical water pumping system – an offense which, according to the Torah, can be punished by stoning.
Rabbi Landa was asked to address the issue by his city's residents. After realizing that it concerned many Jews all over the world who live in multi-story buildings, he decided to delve into it.
For several weeks he consulted professionals in order to understand the mechanism leading the water from the pool to the apartments, and looked into different alternatives presented to him.
After concluding his inquiry, Landa ruled that "any person with technical knowledge can easily understand that a pump operated upon the opening or closing of the faucet means is basically being turned on on Shabbat."
According to the rabbi, the long-term solution is to install a high water reservoir enabling natural rather than electrical pumping. In the meantime, however, "there is no other choice but to ensure that the pump is turned throughout Shabbat and Jewish holidays."
This would require the installment of a special faucet which moves unused water back to the underground pool.
At the end of his letter, Rabbi Landa calls on the residents to accept the financial expenses involved in the solution and the noise expected to disrupt the day of rest until a permanent solution is found.
"On the contrary, hearing the sound of the pump will bring you some Shabbat entertainment and the joy of a mitzvah," he wrote.
Following the halachic complication, the rabbi's aides are calling on building contractors to consult rabbinical authorities before installing such pumps in the city's apartment buildings in order to prevent Shabbat desecration in advance.
They explained that the wider public was unaware of the issue and that contractors were therefore causing residents to commit acts banned by the Torah.