The Oregon Health Authority has set water treatment targets for the Portland Water Bureau. These targets reduce corrosion in plumbing through adjusting the pH of the water. The Water Bureau has measured at least a 50 percent reduction in lead at the tap with pH adjustment.
In January 1997, the Portland Water Bureau began corrosion control treatment, raising the pH of the water to make it less acidic and less likely to leach metals. The treatment consists of adding 4-5 milligrams per liter (parts per million) of sodium hydroxide as part of the water treatment process. The target pH range is 7.8 to 8.0.
Adjusting pH helps reduce levels of lead and copper in tap water in some homes and businesses, and in wastewater treatment discharges. For water-related activities or hobbies affected by changes in pH, consumers should always follow professional instructions from the product manufacturer or hobby consultant. This includes swimming pools, hot tubs, aquariums, beer or wine making, pet fish, etc.