AWWA ACE70859

This powerpoint presentation begins by providing a brief overview of the adverse consequences of partial pipe replacements and the practical concernsrelated to galvanic corrosion andPSR. Topics presented include: chloride to sulfatemass ratio (CSMR)sample calculation; causes for concern - high CSMR; and, experimental design -Cu2+ Deposition Corrosion. Cu2+ Deposition Corrosionconclusions:trace levels of Cu2+ (even 0.03 mg/L)increased lead release from lead pipe w/nogalvanic connection to Cu;deposition corrosion significant concern interms of lead leaching as per prior research; and,putting a copper pipe before a lead pipe inthe flow path, as occurs in partialreplacement, is a concern. Mechanisms ofgalvanic corrosion(Pb Pipe - Cu Pipe),new vs. aged Pb pipeCSMR is presented, along with simulated small scalepartial replacements. Conclusions indicate that:Cu2+ in water increases Pb in water(deposition corrosion); galvanic corrosion of Pb/Cu couples can besignificant - lower pH and higher Cl- at Pb junctionduring stagnation, andPb is sacrificed; simulated partial service line replacement,higher Pb (> 200%) in low CSMR water,higher Pb (>165%) in high CSMR water, andshort length of Cu relative to Pb hadhighest Pb release. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2009

Number of Pages:

54

File Size:

1 file , 2 MB