AWWA ACE70834

This powerpoint presentation begins by providing a brief overview of pilot test protocols that included: constructed test loops at 5 sites;loops contained four 6 in. long segments of: 3/4 in. lead pipe, 3/4 in. copper tube with 5 in. long bead of 50/50 lead-tin solder, and 1/4 in. diameter bar of leaded brass in 3/4 in. PVC; water flow was 5 gpm (3.6 fps) in each of 3 parallel legs;fed identical phosphate doses (based on plant PO4 dose) ineach leg with high zinc concentration (1:1 or 1:3 ZOP), lowzinc concentration (1:10 ZOP), or no zinc (75% PO4);used a 10-hr stagnation period nightly; and,operated each loop for six months. A summary of corrosivity results is provided, along with a summary of water quality results. Study conclusions indicate that: overall, zinc does not appear to have a substantial impact oncorrosivity of lead, copper or mild steel;zinc does not appear to play a role in protection of steady-statemetal release from piping materials, its role in therelease of particulates, especially lead is unclear; and,at locations where differences were statistically significant,no clear pattern emerged - sometimes zinc improvedperformance, sometimes it hindered performance. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2009

Number of Pages:

26

File Size:

1 file , 1.3 MB