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Coliform Coliform organismsorganisms
Elvire Jacques, MDElvire Jacques, MDEnvironmental healthEnvironmental health
Safe Drinking Water Act Safe Drinking Water Act (SDWA)(SDWA)
19741974 EPA regulates contaminants which EPA regulates contaminants which
may be health risks and which may may be health risks and which may be present in public drinking water be present in public drinking water supplies.supplies.
Revisions 1986, 1996Revisions 1986, 1996
Microbial indicator of fecal Microbial indicator of fecal contaminationcontamination
Always found in warm-blooded Always found in warm-blooded animal feces animal feces
Greater number than pathogensGreater number than pathogens Cannot multiply in waterCannot multiply in water Simple, reliable identification testsSimple, reliable identification tests Increased resistance to disinfectants Increased resistance to disinfectants
Dutka, Jrnl Environmental Health 36:39-46,1973Dutka, Jrnl Environmental Health 36:39-46,1973
Coliform organismsColiform organisms
Gastrointestinal tracts of humans Gastrointestinal tracts of humans and animalsand animals
HarmlessHarmless
Different species Different species Escherichia coliEscherichia coli Klebsiella speciesKlebsiella species Enterobacter speciesEnterobacter species Citrobacter speciesCitrobacter species Proteus speciesProteus species Misc.Misc.
EPA health goalEPA health goal
Total coliforms = zero Total coliforms = zero
Legal limit on total coliformsLegal limit on total coliforms
Systems must not find coliforms in Systems must not find coliforms in more than 5% of monthly samples to more than 5% of monthly samples to meet EPA's standards. meet EPA's standards.
If more, report violation to the state If more, report violation to the state and the public and the public
ContaminanContaminantt
MCLG MCLG (mg/L)(mg/L)
MCL or TT MCL or TT (mg/L)(mg/L)
Health Health effectseffects
SourceSource
CryptosporidiuCryptosporidiumm
00 TTTT GI illnessGI illness Human Human and animal and animal fecesfeces
GiardiaGiardia 00 TTTT GI illnessGI illness Human Human and animal and animal fecesfeces
LegionellaLegionella 00 TTTT Legionnaire’Legionnaire’s diseases disease
waterwater
Total Total coliform coliform (fecal colif (fecal colif and and E. coliE. coli
00 5%5% Presence Presence may may indicate indicate other other harmful harmful bacteriabacteria
EnvironmeEnvironment Fecal nt Fecal colif. and colif. and E. coli from E. coli from human and human and animal animal fecesfeces
Viruses Viruses (enteric)(enteric)
00 TTTT GI illnessGI illness Soil runoffSoil runoff
The presence of coliform bacteria in The presence of coliform bacteria in tap water suggests that the tap water suggests that the treatment system is not working treatment system is not working properly or that there is a problem in properly or that there is a problem in the pipes the pipes
Contamination, then what?Contamination, then what?
Repair the disinfection/filtration Repair the disinfection/filtration equipmentequipment
Flush or upgrade the distribution Flush or upgrade the distribution systemsystem
Enact source water protection Enact source water protection programs to prevent contamination. programs to prevent contamination.
Total coliform positiveTotal coliform positive
Repeat samples within 24 hoursRepeat samples within 24 hours Analyze for fecal coliforms and Analyze for fecal coliforms and
Escherichia coli (E. coli)Escherichia coli (E. coli) Positive fecal coliformPositive fecal coliform
MCL violationMCL violation State and public notification because of State and public notification because of
direct health risk. direct health risk.
Water Treatment AgentsWater Treatment Agents
ChlorineChlorine OzoneOzone SunSun Filtration systemsFiltration systems
Ozone treatmentOzone treatment
Water treatment plantWater treatment plant
