This wasn't mentioned above, so I'll say it here...
Silica (sand) may no be bad for you health-wise, but having it go through a pump (any pump) will ruin it. You may be able to get it rebuild a few times, but in the long run it will destroy the internal parts.
Depending on the type of well, you may need to have it blown out to remove the sand. But if there is sand, there's a possibility of there being a break in the well casing, which most of the time is not repairable...