A lot of sins can be washed away if you picked the right market/sub-market. 

Since the house had no basement, the water leak most likely washed away some soil beneath the building.So, bottom line is, have it checked out quickly.

The best I thought of was to not allow outside water use (car washes, etc...) and install low flow shower heads and toilets.

The best part about this call was he kept saying, "You've sent me a bunch of mail but this is the first time you've ever answered.

Was he actually talking to you, or you overheard the situation?

When I owned my restaurant grease trap was directly under the washing sink and cleaned out on a regular schedule.A tip when looking at an existing restaurant or one that went out of business is to inspect the grease trap.

My worse clean up, I had to take a garden hose into the house to wash it out.

I dug up all of them and wash them off.

Anyone ever hear the term "wash well"?

Wash window sills and curtain rods.