Water Leak / Slab Foundation - Help!
We received our water bill the other day and it was 4 times the usual expense. Actually, this is the 2nd month it's been high. The first time I thought it was because of a leaky toilet that I fixed in early January. But no, we definitely have a water leak somewhere.
Here is what I know:
With all faucets off, I can see the water meter moving. Closing off the main supply causes the meter to stop. Both toilets shut off makes no difference.
We are using ~2500 cf of water per month instead of the average 800.
A guy came to look yesterday and taped out everywhere our supply pipes are underground and under the slab. He thinks the leak is NOT under the slab because there is no moisture coming up through the slab that any of us can detect.
We had an electrical wire put in a trench this summer that crosses the supply line. We were theorizing that perhaps they nicked the pipe and eventually caused it to leak. So I dug a hole near the intersection, but the dirt doesn't appear to be abnormally wet in that area. Not exactly sure what to expect however. This is western Oregon by the way.
Any thoughts on how I can figure out where the leak is? Does water normally come up through the slab when there is a leak as he suggested? Any help would be appreciated!