Page 39 - GPHS Environmental Public Health Standards (Foundation of Public Health) v1
P. 39
Potable Water - Main risks - Harmful microbes in water
Total coliforms
Intestinal Enterococcus
➢ Coliforms are a broad class
of bacteria and include Escherichia coli
those that can survive and ➢ The intestinal enterococcus
grow in water. ➢ E. coli is a type of group can be used as an
➢ Hence, they are not useful coliform and is index of fecal pollution.
as an index of specific fecal considered the most ➢ Most species do not multiply
pathogens, but they can suitable index of fecal in water environments.
be used as an indicator contamination ➢ Important advantages of this
of treatment monitoring, including group are that they tend to
effectiveness, and to surveillance of drinking- survive longer in water
assess the cleanliness water quality. environments than E. coli
and integrity of ➢ The guideline value is or thermotolerant
distribution systems, and zero (0) E. coli per 100 coliforms and are more
the potential presence of ml of water. resistant to chlorination.
biofilms. ➢ Guideline value is zero(0)
➢ The guideline value is zero per 100 ml of water.
(0) coliforms per 100 ml of
water
