From: Rabbi Moshe Sofer
To: Rabbi Getz
The Chasam Sofer rules unequivocally that the mikvah is invalid on multiple grounds: the tub suspended by chains is not attached to the ground and retains full vessel status; when the plug is closed during immersion, the tub is disconnected from the spring, invalidating immersion on a Torah level; and in practice, the women testified they never opened the plug at all. He orders the ruling to be publicized.
Source: Shu"t Chasam Sofer YD §206