A program was set up to analyze the quality of the various water streams in a boiling water reactor during routine and transient operation. Feedwater, reactor cleanup outlet water, control rod drive water, and reactor water samples were analyzed for dissolved oxygen content, pH, and conductivity. Close attention was paid to transient conditions, and these were carefully documented as to cause and effect. Nearly 2000 data points per day were collected, while weekly calibrations were performed to maintain system accuracy.