Although utilities strive to maintain water quality from the
treatment plant, through the distribution system, and into
customers' homes and businesses, at times microbial
indicators are present but go undetected in treated water. This
results in apparent contamination downstream in the distribution
system.
Causes of this contamination can be diminished by tracking
and eliminating low-pressure events (including transitory ones),
cross-connections, and inadequate disinfection procedures during
distribution system maintenance. However, the complexity of
distribution systems and the dispersion of related information,
such as water quality, hydraulics, asset condition, and operation
and maintenance, often prevent the causes of water quality
failures from being identified. This lack of understanding of the
origin of positive coliform samples leads to a nonactive approach
as long as the problem is not acute with regard to public health or
compliance issues.
Key points to understanding and solving coliform existence
in distribution system water include taking into account the
hydraulics and daily operation and maintenance of storage
tanks and pipe systems. The authors believe that analyzing
coliform problems is the first step toward solving them, and
they review the parameters involved in understanding and
predicting these problems. They also make a strong case for
replacing coliform testing with Escherichia coli-testing as a
regulatory tool. Includes 151 references, tables, figures.
| Edition : | Vol. 94 - No. 8 |
| File Size : | 1
file
, 1.2 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 15 |
| Published : | 08/01/2002 |
