John H. Schnieders, FAIC, CPC, is the principal chemist of Water Systems Engineering Inc., an investigative and chemical systems design laboratory. Schnied ers' presentation, "Chemical Rehabilitation of Wells," included: a review of chemicals available for well cleaning; discussions of mineralization and biological fouling, major causes of production loss and water quality problems; guidance on selecting the right chemistry for the problem; a review of how to determine the correct amount of acids, enhancers, etc.; examination of mechanical applications and why they are necessary; and some disposal and preventative maintenance considerations.