Charles, I can check but not send e-mails until I get back to work on Tuesday so I will try to answer your question in a simple way right now.
I will try to draw a design of how I drill wells and scan them and post here on the DP as soon as I get a chance.
Now on to your problem:
Sand can eventually clog all wells. For years I use to shoot my well. I used a Smith&Wesson 38 special with 158gr hollowpoints. I know it sounds strange but align yourself over the well and shoot it. The impact of the bullet will clear the strainer for quite some time. I used this method for about 8 years at one of my previous homes. Don't worry the bullet will just sink to the bottom and cause no problem.
This will get you through until you can drill another.
1976-1982 USMC, Having my hands in the soil keeps me from soiling my hands on useless politicians.