More utilities are using chloramines in place of free chlorine because of their greater stability for
better compliance with both the Total Coliform Rule and more stringent requirements of the
Disinfectants/Disinfection Byproducts Rule. New information about disinfectant-induced changes in
oxidation reduction potential (ORP), lead chemistry, scale formation and interactions with natural
organic matter have contributed to a greater understanding of the factors influencing increased
corrosion and metals release associated with a change in disinfectant. As such, AwwaRF funded this
project (#3107) to build upon the water industry's limited understanding of this effect. This project
includes laboratory studies and a field sampling program. Identical pipe-loop setups and components
testing procedures are being conducted at the HDR Applied Research and Technology Center
(ARTC) in Bellevue, Washington and the District of Columbia Water and Sewer Authority (DCWASA)
testing facility in Washington, DC. This paper provides a brief description of the setups, operations,
preliminary data, and discussion of preliminary results. In general, preliminary results indicate the
presence of chlorine tends to suppress lead release from old lead pipe but this effect appears to be
less prominent for newly exposed lead-bearing materials. At the same time, copper release appears to
be accelerated in the presence of chlorine. Both these effects are affected by water quality
parameters, scales present on the surface and overall exposure history of corroding surfaces. Results
from this study will be of interest to utilities that are considering converting from free chlorine to
chloramines, and/or utilities concerned with maintaining simultaneous compliance with the Lead and
Copper Rule and the Stage 2 D/DBPR. Includes 24 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 20 |
| Published : | 11/01/2007 |
