The well is giving out. Two years of low rainfall has reduced production such that the pump runs for just a few seconds before shutting off again. I just increased the recovery time between pump runs to see if that helps things, but I doubt it. Talking to my neighbors, it seems that many wells in the area are going dry. We've not had this happen before with our well, but there's a first time fore everything.
Yesterday I had 3800 gallons of water delivered to our tanks, and it will probably require several deliveries before any rain - whenever that begins in earnest - starts to improve our well's output. It will be interesting to see how long that takes.
I may have mentioned this before, but those of you considering a rural lifestyle take note: maintaining your own water supply is not simple, inexpensive, nor for the faint of heart. It's much nicer if you can just open the tap and get clean water.