The field tests were conducted under reducing and oxidizing conditions. Corrosion rates with zero oxygen were about 1.1 mils per year (mpy) for both copper and steel coupons, which is quite low for carbon steel. There was a problem controlling the oxygen level in the oxygenated experiments; however, it was found that corrosion rates increased with the presence of oxygen. Corrosion rates for the steel and copper coupons were 4 and 2 mpy, respectively; copper coupled to cast iron corroded at 8 mpy. Commercial corrosion rate measuring equipment determined the general corrosion rate of carbon steel farily well but overestimated copper corrosion rates. The redox electrode was a very sensitive indicator of the entry of oxygen; PNL-3385