Existing Methods of Waterborne Pathogen Detection - Waterborne Pathogens: Detection Methods and Applications - page 41

the design and implementation of other types of monitoring; or the
monitoring undertaken by water providers, or the regulatory bodies,
to ensure water treatment processes are providing the required level of
public health protection; or the verification of treatment processes, vali-
dating them for future use.
2. operational monitoring aimed at providing additional and essential data
on water bodies at risk or failing environmental objectives of a WSF/
WSP; this operational monitoring should provide information for
instant action.
3. investigative monitoring aimed at assessing causes of such failure; or
at understanding the pathogen load in source waters; or tracking the
source of an outbreak.
Surveillance and verification of treatment systems are performed by water
providers who need to maintain constant vigilance over the security
of their water supply systems. Once treated water enters a distribution
network, it may be vulnerable to ingress of contamination in a number
of ways. Also, even though treated to the required standard, it may still
undergo deterioration in quality during transit to the consumers' taps.
Once a disinfectant residual is applied, it may decline in concentration,
until it is no longer sufficient to control the growth of organisms. With
aging assets, it is vital that water providers are able to maintain confidence
in the integrity of their networks and have the means for early detection
of vulnerability in their infrastructure and its adverse impacts on water
quality. Traditional monitoring is not appropriate since it can take, at best,
nearly a day before the outcome of a routine test is known for a bacte-
riological indicator organism. The ability to monitor more frequently for
specific waterborne pathogens of concern would greatly improve public
health protection. Water companies would be able to respond much more
rapidly to potential incidents before drinking water reaches the consumer
or is used for food production.
Operational monitoring is a key part of WSP approach, enabling
water providers to take up-to-date decisions about the quality of the
delivered water and adjust processes accordingly. The WHO considers
that this type of monitoring should be comprised of simple observations
and tests in order to rapidly confirm that control measures are continu-
ing to work. As stated above, traditional microbial monitoring suffers
from the speed at which results can be provided, since finished waters
will have reached consumer taps before results can be acted upon.