I live in one of those old ranch houses where the washer/dryer are in the kitchen. The kitchen is U-shaped and the W/D is in one side of the U, and the sink is in the bottom of the U. The dishwasher is to the right of the sink, also in the bottom of the U. Lately I have been noticing a slow trickle sound coming from the washer drain pipe when the washer has not recently been in use (at least 24 hours). I was beginning to be concerned that there might be a leak or clog that should be checked out. Today I had a load of laundry running while I was washing dishes. When I let the sink out, I turned on the disposal. After 10 seconds or so, water came rushing out from under the washing machine. It looked like the area at the top of the drain was wet, so I was assuming it overflowed there. Is it just that I was doing too much at once with the disposal forcing the water through too quickly while the washer was going (I didn't think it was on the drain cycle, but it may have been), or is there likely a clog building not allowing enough water through at once? Thanks for your help!--- New Housewife

Sounds like you have a partial blockage in drain pipe. The disposal is forcing water into the drain faster than it can flow out and it is backing up the washer stand pipe. Remove trap under the sink and snake drain line.