Wisdom from the ages: build your house on rock, not sand.
From experience (unfortunately) I can corroborate that sand around the house = water in the basement. Ok, sand sucks, rock is better. But the ages forgot to mention radon gas. Not all rocks are created equal.
Granite = uranium = radon gas = bad
We moved two weeks ago. A few days ago I plugged in the radon detector. Given the geology of the city we now live in is about 90% limestone, I thought nothing of it other than peace of mind.
After the two days it takes the device to get an average reading, I looked. A little high. Huh. No biggie, probably an anomaly. I reset the device.
Two days later, the alarm went off. What the fuck??!
I found a geological map of the area and learned we are sitting on one of the few little chunks of granite in the whole city.
Figures. It also turns out limestone can contain radon picked up from surrounding rocks.
Our readings so far are just over the EPA limit. Livable, perhaps, if it were just hubby and me. But exposing a one year old to the approximate equivalent of 200 chest x-rays/year isn't cool with me.
I think we're moving...again. More to come.
Moral of the story? Build your house on stone...just not the radioactive kind.