Praying in a place under which there is a sewage pipe

There is nothing wrong with this so long as (the
apartment) is separate (from the pipe). Al-Imaam al-Muwaffaq, the author
of al-Mughni and of al-Sharh
al-Kabeer, said: It is permissible to use the area above the
roof of the pipe and similar places, because the pipe is beneath and there
is a roof over it. It is not allowed to pray in toilets and similar
places, but according to the correct view, it is permissible to pray and
read Qur’aan on the roof over them, as we have stated above. Some
scholars said that it is not permissible to do that, but the correct view,
in sha Allaah, is that it is OK. And Allaah knows best.