Slow drainage when flushing toilets.
Water backing up into sinks, toilets, tubs and washing
machines.
Unusual "gurgling" sounds when running water or flushing
toilets.
Areas of grass of a deeper green color than the surrounding
grass on your lawn.
Noticeably soggy areas of the lawn or soil.
Depressions forming in the soil.
Unpleasant odors in, or around the house.