This powerpoint presentation begins by providing a brief overview of the City of Raleigh distribution system, water quality parameters affected by nitrification, the current Total Coliform Rule (TCR), and possible future regulatory compliance. The beginning of coliform studies by CDM in 2004 is presented, along with a water quality monitoring plan, and distribution system field studies. A 2005 CDM distribution system water quality field study is outlined, including sampling plan improvements, TCR sample site plan update, and study completion and summary of changes
implemented. Results achieved include the following:
dramatic decline in number of coliform positives;
improved communication within the Water Plant
Division, and between the Water Plant Division and other
Public Utilities Divisions using GIS;
tracking and trending of laboratory data; and,
better prepared when drought hit in 2007-08. Summary of key past and future items that
improve TCR compliance is presented, including the following:
high residual chlorine concentrations;
additional monitoring and enhanced operation of
distribution system to keep tanks turned over and
dead-ends flushed and to watch for nitrification;
enhanced full-system flushing with elevated amounts
of free chlorine flushed though sample sites, deadends; updated TCR Sampling Plan;
improved model and identification of isolation zones;
developed a Department Operating Procedure for
coliform occurrence investigation and bridge
department sharing of relevant information with GIS (spot
flushing, main breaks, sample plans, new lines,
backflow, plumbing), Response Team formed;
expand cross-connection control program, site
plumbing investigations;
implement nitrification control procedures (lower
ammonia, flushing, etc.); and,
corrosion control and infrastructure upgrades and
maintenance. Includes figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 2.8 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 37 |
| Published : | 11/01/2008 |
