I have a 10 yr old 480' deep well (100gpm) pump at 300' that has become completely clogged. My original "well driller" flushed all the mud out of the casing until gravel came out then he let the clear water run all night. During the night the water stopped again because the casing had become completely clogged with mud again. Any ideas or suggestions as to what needs to be done to solve this problem? (in lieu of drilling a new well which is not an option at this point). I've always had great water (with some iron but our Culligan Water System takes care of that for the house) and hope that someone can help me with this serious problem. Thank you in advance for your help.....