If a Mikvah that the rainwater was not changed in many years, maybe up to more than 30, is it still kosher to immerse vessels in it?

 

This is something which, in and of itself, would not generally disqualify the Mikvah.

Nevertheless, there are many things in general which can go wrong and invalidate a Mikvah. Therefore, when a Mikvah is required Min Hatorah (such as for Keilim immersion according to most opinions), one should ensure that it is under the Hashgocha of a Rov who is proficient in Hilchos Mikvaos. If it is not under the Hashgocha of a Rov, one should not automatically presume that it is Kosher.

 

 

#5256