When my washing machine drains, some of the water backs up into my utility sink. Last night I used my disposal in the kitchen, ran water and all was fine. I put in 3/4 load of clothes and left the house. When I returned the floor was wet and the utility sink was full. I assumed it ran over onto the floor. We drained most of the water from the sink into a nearby toilet. I ran water in the upstairs sink and the utility sink began filling up. It sat all night and was drained this morning. When I came home from work, I ran water in the kitchen sink along w/ liquid dish soap. The washer stand pipe showed about 5 inches of bubbles on it and the utility sink was filling up w/ water again. HELP - where is the clog?

Sounds like your blockage's downstream from the utility sink. The solution would be to snake from the utility sink roof vent or a cleanout in a basement stack if you have one. You may also snake from the washer stand pipe if you wish. If you go down the roof vent put out enough cable toreach the base and 20 feet more. Good luck, Tom