A wide held requirement for the minimum volume for a kosher mikvah is 40 se'ah.
Is it permissible to use a 40 se'ah puddle as a keli mikvah? Are there additional requirements such as a minimum depth, or whether the puddle needs to hold the water i.e., water isn't following out etc.?
I appreciate that it may be a considerable concern regarding the safek of the size of the puddle e.g., if the water if unclear (e.g. dirty, murky, filled with leaves). This may be considered in the answer. However, considering that a layman would be able to distinguish a large puddle (e.g. one that may fit a car) even if waters are murky, would it be permissible to use such a body of water as a mikvah to tovel keilim.
I think the question applies for a person immersing in the mikvah, but I don't want to get in to the territory of tzniyut etc.