We recently began to get the smell of mildew from our basement. When we dug into it, we found the felt around the pipes entering the gray water holding tank to be be very damp. Looking closer, we found that the down pipe from the washer/dryer was cracked.
The crack ran almost completely around the point of entry into the holding tank (circumferential). We had stored a heavy cast iron grill between the pipe and forward wall along with a small shovel and other "junque". Pressure from these stored items against the pipe was enough to break it.
So, after an emergency response by a mobile RV repairman ($165.50) and replacement of part of the down pipe, we are able to use the washer again. BE AWARE...different items stored in the basement can move and cause damage. Now I have to rethink my entire storage plan.