A study was conducted in Seattle, Washington, to evaluate the use of lime and sodium bicarbonate in surface water supplies to control corrosion of plumbing materials. Continuous-flow pipe-coupon test loops were used to test the effectiveness of two water treatments - addition of lime only, and lime plus sodium bicarbonate. Three commonly used plumbing materials (copper, galvanized steel, and black steel) were tested for corrosion type and rate, penetration rate, and metal leaching. Corrosion rates were evaluated through weight loss, penetration rates were tested with pitting depth measurements, and corrosion types were determined by visual observation. Metal leaching tests were conducted using small-diameter pipes which exaggerate the test results and thus enable meaningful comparisons to be made in short-term tests. This method was developed by the Seattle Water Department for this study.