since I am late to the thread I just want to mention my own experience with low water pressure on a residential well - turned out that the well pump was gummed up with manganese - well guy rebuilt the pump and it has been running fine for the past 8 years
we have high manganese content at certain times in the year, so I do expect the well pump to gum up eventually again - presumably "shocking" the well periodically can help, but in my area, the 'well-shocking' costs as much as 65% of the rebuild (due to the depth of well and equipment needed), so I will wait until the pump needs a rebuild and have the well 'shocked' at that time