This study investigated 16 repair sites of drinking
water mains to monitor the effect of main repairs on
water quality. Samples were collected from the distribution
system and from the soil and groundwater surrounding
the mains. Changes in water quality outside
the isolated repair area were also monitored.
A total of 424 water samples collected from consumers'
homes and flushed hydrants were assayed for
total coliforms, Escherichia coli, and aerobic
endospores. Total coliforms were detected in 4.0% of
these samples and E. coli in only a single sample.
Almost all of the positive samples (16 of 17) were collected
during the flushing step of the repair process.
Water quality changes, including losses of chlorine
residuals and peaks in turbidity, were also observed
outside the repair area.
Repairs of water mains are routinely conducted
by water utilities, and, moreover, the frequency of
repairs in some systems can be quite high because
of the system's age and resulting deterioration.
Water utilities should have measures in place to
ensure that their operational practices are adequate
for public health protection as well as for regulatory
compliance. Includes 36 references, tables, figures.
| Edition : | Vol. 100 - No. 7 |
| File Size : | 1
file
, 730 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 15 |
| Published : | 07/01/2008 |
