Controlling copper corrosion in new construction by organic matter removal Roge R B. A R nold J R., 1 Alli A n gR iffin, 2 A nd M ARC e dw AR ds 3

A new elementary school with persistent elevated copper corrosion by-product release evaluated pH increase, orthophosphate dosing, and granular activated carbon (GAC) treatment as potential corrosion control measures using bench-scale experiments. Removal of natural organic matter (NOM) with temporary GAC treatment facilitated the formation of a copper scale with a permanently diminished (> 85%) solubility via an accelerated natural scale-aging process. Increasing the pH and adding a high dose of orthophosphate were also effective for decreasing copper release but presented significant long-term drawbacks, and their benefits were reversed if the treatments were discontinued. Temporary GAC treatment may be a holistically attractive option to reduce copper corrosion problems in new construction in certain waters with high levels of NOM.