This paper summarizes results of recent analyses performed by Battelle-Northwest in EPRI project RP 653-3: Computer Simulation of Scaling in Geothermal Systems. The results reported here are drawn primarily from case evaluations performed over the 12 months since the preceding EPRI Geothermal Symposium held in Monterey in June 1979. The present project is a continuation of a previous project designated RP 653-1. The ultimate objective of research performed in this project is to develop analytical tools (computer codes) and the supporting thermophysical and chemical data base that can be used to predict scaling and corrosion in geothermal power generating systems