Washing Machine Drains = Bathtub Fills Up W/ Sewage?
Okay so my title is just a hint of the trouble I have recently encountered.
A couple days ago I did a load of laundry and noticed that the bathtub was full of sewage about 45mins after starting the laundry load.
Puzzled it took me until the next day to figure out they two events were related. It seems as though when the washing machine drains; the kitchen sink, bathroom toilet & bathtub all fill up with sewage coming UP THE DRAIN!!
Now when not doing laundry, the toilet flushs fine, the bathtub drains fine, and the kitchen sink drains fine... THIS ONLY HAPPENS WHEN I USE THE WASHING MACHINE.
ABOUT THE PLUMBING:
The washing machine drains into a long metal tube that comes out of the ground. It tees into a big black pipe in the basement, as does the toilet and bathtub kitchen and bathroom sink.
I noticed that the ground is wet in the basement right under the toilet hookup...
ANY IDEAS AS TO WHERE TO START WOULD BE TOTALLY APPRECIATED!!