Waterborne Disease Outbreaks and the Multi-barrier Approach to Protecting Drinking Water - Global Drinking Water Management and Conservation - page 16

severity of the outbreak, by approving plans for the construction of an ultra-violet
light treatment facility. Ultra-violet (UV) treatment has been proven to be effective
against protozoa, and therefore is the right step toward preventing future outbreaks.
In May 2000, August 2000, and April 2001 three outbreaks of cryptosporidiosis
occurred in Northern Ireland. Respectively, 230, 117, and 129 cases of illnesses
were reported in unrelated cases in different locations within the Belfast Area.
These outbreaks are small when considered in proportion to the population of
approximately 400,000 people in the greater Belfast area. The source of the

rst
outbreak is believed to have been livestock runoff, the second source is believed to
have been human sewage from a septic tank, and the third is believed to have been
wastewater from a blocked drain (Glaberman et al. 2002 , p. 631). Chlorine is
commonly used in Ireland, but in this case it is again proven that chlorine is
ineffective against the Cryptosporidium pathogen. Filtration was in place in the
third outbreak, but the blocked drain would have allowed the contaminated water to
enter the finished water supply. Ireland primarily relies on surface water sources for

drinking water, and these sources are vulnerable to contamination because of fre-
quent heavy rainfalls and the large numbers of farms with livestock (Zintl et al.
2009 , p. 271). This combination poses a serious threat to the safety of drinking
water. Although high numbers of livestock are a major concern, only the

rst
outbreak was caused by Cryptosporidium of an animal genotype, while the second
and third were caused by Cryptosporidium of a human genotype (Glaberman et al.
2002 , p. 632). With the knowledge of a high likelihood of contamination, whether
due to animal or human fecal matter, monitoring and treatment in the area would be
necessary in order to avoid future outbreaks. The three outbreaks re ect poorly on

the ability of Ireland s water system to monitor and treat their water effectively.

In April 2001 an outbreak of cryptosporidiosis occurred in North Battleford,
Saskatchewan. This outbreak caused between 5,800 and 7,100 cases of illness, in
the city of approximately 15,000 people. The surface water source of North
Battleford is the North Saskatchewan River, which at the time had no protection
programs established to prevent source contamination. The treatment at the plant
included both chlorination and

'

filtration. It is believed that the source of contam-
ination was sewage from a sewage treatment plant 3,500 m upstream from the
intake of the drinking water plant (Hrudey et al. 2002 , p. 401). The sewage treat-
ment plant was reported as not meeting operating standards due to old equipment
and inadequate practices (Woo and Vicente 2003 , p. 261). Another possible source
of contamination could be calf feces runoff from the agricultural activity in the area
in combination with heavy spring rainfall (Woo and Vicente 2003 , p. 261). Again,
treatment failure was the main problem within the water system that should have
been able to prevent the outbreak. Inadequate coagulation, which is part of the

filtration process, was the cause of the outbreak. Also a lack of knowledge and
education on the topic of water treatment, particularly concerning the speci

c
pathogen Cryptosporidium, was determined to be an issue concerning the capa-
bilities of the plant staff (Woo and Vicente 2003 , p. 262). Overall the North
Battleford outbreak revealed a variety of problems that allowed the Cryptospori-
dium pathogen to enter the drinking water system.