Applications of Emerging Technologies in the Drinking Water Sector - Waterborne Pathogens: Detection Methods and Applications - page 354

responsible for minimizing the chance of untreated sewage entering the
sea, but sometimes it is hard to avoid, such as in instances of leaking septic
tanks or overflowing sewers in the beach vicinity, and thus there is always an
inherent risk to the public using these areas. 44
Use of water in agriculture also provides a potential entry point for bac-
teria and protozoa. Water is predominantly used in agriculture for crop irri-
gation, produce washing and livestock drinking. The sources of the water
used are predominantly rivers and streams but also boreholes, ponds, and
lakes; only a small amount (about 2%) comes from water mains. A portion of
this water is likely to contain pathogens that could go on to infect livestock
or contaminate crops. It is therefore necessary for the quality of water used
for irrigation to be controlled and assessed prior to use to prevent water-
borne pathogens from passing to humans in this manner. 45
In the UK a high percentage of outbreaks of disease caused by pathogens
in water is associated with private supplies. In particular, Cryptosporidium ,
Giardia and Campylobacter have been associated with private supplies. The
reasons for the contamination may include water being derived from surface
water or springs that are within the agricultural catchment and therefore
prone to inundation of contaminated agricultural run-off. 46 Additionally,
water used as a source for small supplies may be subject to a higher prob-
ability of containing pathogenic microorganisms, making it vitally impor-
tant that a multibarrier approach is used for treatment to ensure all different
pathogenic agents are removed. 46 The number of outbreaks resulting from
public supplies is considerably lower than from private supplies, which is
believed to be due to the fact that they tend to employ a multibarrier treat-
ment system more often than private supplies.
Public health plays a key role in, and considerably determines, targets
for water quality and the definition of what constitutes “safe” in drinking
water. Targets for public health are essentially translated into the standards
for water suppliers set through legislation. 18
11.6. DETECTION AND TREATMENT FROM A MARKET
PERSPECTIVE
A range of water monitoring, pathogen detection and treatment pro-
tocols and systems have been developed over the past 20 years, both to satisfy
the requirements of water supply and water treatment companies and to
ensure that the regulator is satisfied that potable water is of a sufficiently high
standard to be supplied to customers. Various approaches are reviewed here.