Thanks for the help.
I had some well guys out here a few times, and whenever tradesmen come by, I drive them insane with questions. They figured my well was probably around 60 feet deep, but they would have to pull the pump out to be sure.
There is no possible way this house was treated with Chlordane because it was built in 2000 on a freshly cleared lot. I doubt any house within half a mile was built before 1990.
I've used glyphosate and 2,4D here. Not that it does much good in the weed-growing capital of the universe. I also use imidacloprid from time to time. Again, not that it does much good.
There is very little crop farming here because it's impossible. It's basically hobby farms for horse lovers. Any agricultural chemicals of consequence would have to come a long way. A neighbor has a "blueberry farm," but it's really a tax dodge, like the cattle on my land. He has like 200 organic blueberry plants, and he pretends to run a u-pick. In exchange, the state cuts his taxes by 50%. I have a 14-acre pasture with maybe 8 cattle, and the tax bill last year was about $110.
Until about the time I started brewing again, I drank bottled water because I didn't want tons of calcium in my system. I've had kidney stones, and I was under the impression, probably mistaken, that hard water made them worse.
One of these days I'll get a test and see what's happening.