The problem you describe is ...
Published by Michael Deed, Geoquip Water Solutions Limited - Managing Director
The problem you describe is very likely to be due to iron related bacteria in the water. A soft rich orange brown residue forming on the inside of the well, pipes, pump and other equipment. The best solution is to clean the well and then maintain it in this manner. Have a look at this site and see if the pictures are the same as your well www.wellrehabilitationsolutions.com