Transcript Coliform Organisms - Elvire Jacques, M.D.

Coliform organisms
Elvire Jacques, MD
Environmental health
Safe Drinking Water Act (SDWA)
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1974
EPA regulates contaminants which may be
health risks and which may be present in
public drinking water supplies.
Revisions 1986, 1996
Microbial indicator of fecal
contamination
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Always found in warm-blooded animal
feces
Greater number than pathogens
Cannot multiply in water
Simple, reliable identification tests
Increased resistance to disinfectants
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Dutka, Jrnl Environmental Health 36:39-46,1973
Coliform organisms
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Gastrointestinal tracts of humans and
animals
Harmless
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Different species
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Escherichia coli
Klebsiella species
Enterobacter species
Citrobacter species
Proteus species
Misc.
EPA health goal
Total coliforms = zero
Legal limit on total coliforms
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Systems must not find coliforms in more
than 5% of monthly samples to meet
EPA's standards.
If more, report violation to the state and
the public
Contaminant
MCLG (mg/L) MCL or TT
(mg/L)
Health
effects
Source
Cryptosporidium
0
TT
GI illness
Human and
animal feces
Giardia
0
TT
GI illness
Human and
animal feces
Legionella
0
TT
Legionnaire’s
disease
water
Total coliform
(fecal colif
and E. coli
0
5%
Presence
may indicate
other
harmful
bacteria
Environment
Fecal colif.
and E. coli
from human
and animal
feces
Viruses
(enteric)
0
TT
GI illness
Soil runoff
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The presence of coliform bacteria in tap
water suggests that the treatment system
is not working properly or that there is a
problem in the pipes
Contamination, then what?
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Repair the disinfection/filtration equipment
Flush or upgrade the distribution system
Enact source water protection programs to
prevent contamination.
Total coliform positive
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Repeat samples within 24 hours
Analyze for fecal coliforms and Escherichia
coli (E. coli)
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Positive fecal coliform
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MCL violation
State and public notification because of direct
health risk.
Water Treatment Agents
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Chlorine
Ozone
Sun
Filtration systems
Ozone treatment
Water treatment plant
Thank you