LaMotte EZ 3-0034 - Manual (Page 10)

such as dogs, cats, birds, mammals, and people. E. coli belongs to both groups of
bacteria that are reported in water quality studies; E. coli is a fecal coliform (FC) and a
total coliform (TC).
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New guidelines from the USEPA recommend E. coli or Fecal Coliform standards that
vary with the potential human exposure to the water. For example, during summer on
a lake which allows swimming and water skiing, the standards will be stricter (require
lower counts) than during the winter on that same lake or if it was a rarely used
swimming area. Each state works with the EPA to determine the best standards that
apply to their water bodies. Refer to the EPA document, “Bacterial Water Quality
Standards for Recreational Waters (Freshwater and Marine Waters)-Status Report” at
this website: www.epa.gov/waterscience/beaches/local/statreptac.pdf for more
specific standards from your state.
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Normal testing for E. coli cannot determine the source of the contamination (e.g.
animal vs. human), since it is present in all warm-blooded mammals. Drinking water
is often drawn from rivers, lakes, streams, and other reservoirs open to non-point
source or point source pollution. Water company scientists measure fecal coliform
bacteria, in addition to dissolved oxygen, pH, temperature, and turbidity to determine
water quality. High levels of fecal coliform or E. coli have caused closures of shellfish
beds, beaches, and other recreational water sources. Point source pollution may be
caused by septic systems, municipal sewage discharges, animal feed operations,
farms, and boaters discharging wastes. Non-point source pollution from E. coli may
be related to runoff of fecal waste from the land after a heavy rainfall. For example, in
urban areas, E. coli runoff occurs from runoff of pet feces in the park or on the street
into creeks, rivers, streams, lakes, or groundwater. E. coli levels in urban storm water
can reach as high as 100,000/100 mL. E. coli levels reaching over 27,000/100 mL
were found in an area where gulls routinely roost in Milwaukee.
Reducing bacterial water pollution involves a whole community working together.
State, Federal, and Local Water agencies, EPA, community leaders, teachers,
students, neighbors, farmers, chemical companies- everybody must work together to
plan a best management strategy for your community. Additional tools are available
under Resources to make an action plan. Education programs show the impact of
individual behaviors on public health and water quality and create a culture for
change.
Def i ni tions
CFU colony-forming units or colonies or cells, one CFU is larger than a
period(.), can be seen without magnification, and may contain more
than 10,000 individual bacterial cells, all clones of the original
bacterial cell
E. coli
(Esch e richia coli)
those bacteria which grow as dark blue/purple colonies on the
Coliscan Easygel plate as a result of the production of both
glucuronidase and galactosidase enzymes. These bacteria are of
fecal origin.
To tal Coliforms those bacteria which make up the sum of the E. coli (blue/purple
colonies) + other coliforms. The other coliforms will appear as
pink/magenta colonies because they produce galactosidase, but
NOT glucuronidase. Species of the genera Citrobacter,
Enterobacter, Escherichia, and Klebsiella are the main groups of
coliform bacteria.
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