A Beginner's Guide to
Water Management Bacteria
Information Circular 106
Department of Fisheries and Aquatic Sciences
Institute of Food and Agricultural Sciences
University of Florida
Institute of Food and Agricultural Sciences U-A THi
This publication was produced by:
Florida LAKEWATCH 2003
University of Florida / Institute of Food and Agricultural Sciences
Department of Fisheries and Aquatic Sciences
7922 NW 71st Street
Gainesville, FL 32653-3071
Phone: (352) 392-4817
Toll-Free Citizen Hotline: 1-800-LAKEWATCH (525-3928)
Web Address: http://lakewatch.ifas.ufl.edu/
Copies of this document are available for download
from the Florida LAKEWATCH website:
As always, we welcome your questions and comments.
A Beginner's Guide to
Water Management Bacteria
Information Circular 106
Department of Fisheries and Aquatic Sciences
Institute of Food and Agricultural Sciences
University of Florida
Institute of Food and Agricuitural Sciences
This publication was produced by:
Florida LAKEWATCH 2003
University of Florida / Institute of Food and Agricultural Sciences
Department of Fisheries and Aquatic Sciences
7922 NW 71st Street
Gainesville, FL 32653-3071
Phone: (352) 392-4817
Toll-Free Citizen Hotline: 1-800-LAKEWATCH (525-3928)
Web Address: http://lakewatch.ifas.ufl.edu/
Copies of this document are available for download
from the Florida LAKEWATCH website:
* A Beginner's Guide to Water Management The ABCs (Circular 101)
This 44-page publication provides a basic introduction to the terminology and concepts used in
today's water management arena, in a user-friendly glossary format.
+ A Beginner's Guide to Water Management Nutrients (Circular 102)
A basic introduction to the presence of phosphorus and nitrogen-two nutrients commonly associated
with algal growth and other forms of biological productivity in lakes. Limiting nutrients are also
discussed, along with conceptual and mathematical tools that can be used to achieve a variety of
water management goals. The booklet is 36 pages in length.
+ A Beginner's Guide to Water Management Water Clarity (Circular 103)
Anyone interested in the subject of water clarity can benefit from reading this 36-page circular.
Topics include techniques for measuring water clarity, the factors that affect it, as well as a
discussion of the techniques needed and/or used for managing it.
+ A Beginner's Guide to Water Management Lake Morphometry (Circular 104)
Knowledge of the size and shape of a lake basin (i.e., lake morphometry) can tell us a great deal
about how a lake system functions. It can also help us appreciate lakes for what they are and manage
them with more realistic expectations. This 36-page booklet is recommended for anyone interested
in learning more about the terminology and techniques currently being used to study lake morphometry
+ A Beginner's Guide to Water Management Symbols, Abbreviations & Conversion Factors
This 44-page booklet provides the symbols, abbreviations and conversion factors necessary to
communicate with water management professionals and scientists in the U.S. and internationally.
Included are explanations for expressing, interpreting and/or translating chemical compounds and
various units of measure.
Copies of any of these publications can be obtained by contacting
the Florida LAKEWATCH office at 1-800-LAKEWATCH (1-800-525-3928).
They can also be downloaded for free from the Florida LAKEWATCH web site at:
or from the
UF/IFAS Electronic Document Information System (EDIS):
'" r ~C'.F .,~u Ir
A after years of working with Florida increase in the number of septic tanks and/or
LAKEWATCH volunteers and discussing municipal sewage treatment plants. With the
lake management issues with them, we've record pace at which many of these systems
come to the conclusion that bacterial contamina- were installed, concerns are re-emerging
tion is one of the major concerns, if not the amongst citizens and some scientists.
biggest, among citizens who live on or use our
state waters. Such concerns are certainly under- Are these concerns warranted?
standable; for centuries, waterborne diseases have As Professor Dan Canfield1 likes to say,
ravaged human populations worldwide and, in "Yes, no, and maybe." No individual or agency
some countries, continue even today. Fortunately, can guarantee with absolute certainty that recreat-
within the United States and Florida, advances ing in a given waterbody is completely without
have been made in the treatment of human waste risk. While this may be an unsettling thought to
that have greatly reduced incidences of disease many individuals, it is important to remember
from contaminated water. that in most monitored waters, there is a very,
very low risk of becoming ill. When you drive
So why are people still worried? your car a few miles to the grocery store and back
It may have something to do with the home, you are exposing yourself to a much
swimming beach closures that occur every greater health risk than one would normally
summer due to high bacteria counts, as well as experience while recreating in Florida's waters.
periodic reports of bacterial contamination in
drinking water supplies. As sporadic as these What should one do if bacterial
S. contamination is suspected?
incidences may be, it is evidence that even with
n t y ad t i m The first thing to do is to stay well informed
modern technology and the improvements made
in wastewater treatment, problems do occur. and this circular provides a good place to start.
in wastewater treatment, problems do occur.
(See the outline provided at the end of the intro-
(As usual, it's the rare problems that we remember, (See the outline provided at the end of the intro-
duction for an overview of the topics covered.)
rather than the many successes.)
These occasional problems seem to Secondly, if you or a group of homeowners
These occasional problems seem to
Suspect recurring contamination and you have
underscore a general apprehension among
S. the financial capability to pay for testing by a
some Floridians that changes in land use and
unprecedented population growth could be private laboratory, we recommend that you do
unprecedented population growth could be
contributing to an increase in the contamination so, as many public health agencies are limited in
Sr l r. W o r t what they can do. If these agencies do test for
of our local waters. When one considers that
e s s pn hs i b m bacteria, it usually involves only one or two
the state's population has increased by more
indicator tests. Then, due to lack of funding and
than 115% in the past thirty years (i.e., since the
1970s), with even more growth expected personnel, their only option is often restricted to
1970s), with even more growth expected
1. simply ordering the site closed until re-testing
during the 21st century, it's no surprise that simply ordering the site closed until re-testing
indicates the water is again safe for use.
people are beginning to wonder about the
This is unfortunate, especially if there is a
effects that such growth may be having on our
lakes, rivers and coastline.
The widespread development of permanent 1 Dr. C is director of Florida LAKEWATCH, a citizen-
homes and businesses, many of them built on or based volunteer water r at the University of
SF 's Department of Fisheries and Aquatic Sciences.
near lakes, has been accompanied by a dramatic
chronic problem that needs to be identified and of the problem may seem obvious at first, it's
eliminated. important to remain objective and not jump to
Whether you hire a laboratory or decide to conclusions before doing one's homework.
collect water samples and do the testing yourself,
we strongly suggest that you refer to the Part 7 The bottom line?
of this booklet for an easy, relatively inexpensive Correcting the problem should be the most
approach to guide you through the process. Even important management objective once the public
if you have the financial resources to pay for more has been warned about possible contamination!
complicated testing methods (also described in The solution to this problem should not be
this circular), we think our Four Step approach is a limited to simply foregoing the use of the
good way to begin and may save further expense in waterbody, but being aware and committed to
the long run. tracking down the source.
Unless there is a catastrophic failure of a Lastly, remember that prudence should
major sewage collection line or septic system, always be the watchword when it comes to human
finding a leak is not always easy or cheap. In health. If you have been swimming in a lake,
some instances, contamination can be the result river or coastal waters and become ill, go see
of outdated or improperly installed septic tanks your doctor and be sure to tell her/him that you
and at other times, miles of leaky sewer lines have been in contact with recreational waters.
may be the culprit. Or it could be from an entirely You'll probably find out that your illness is not
different point of origin; sometimes, bacterial related to a waterborne disease, but if it is, most
contamination is the result of naturally occurring illnesses can be treated quickly and effectively.
animal waste from birds and other wildlife living Should you have any questions or concerns
nearby. "False alarms" are also common. regarding bacterial contamination in your lake,
That's why good detective work is required please call Florida LAKEWATCH:
from both professionals and the general public. 1-800-LAKEWATCH (1-800-525-3928).
Everyone must recognize that, even if the source
Included in this circular:
Part 1 A Brief Lesson On Bacteria 1
+ Bacteria in Lakes, 1
+ Why the Concern? 1
+ Viruses and Protozoa in Water, 2
Sidebar: Amoebas in Lakes, 3
Part 2 Sources of Bacterial Contamination 5
+ Human Waste, 5
+ Domestic Animal Waste, 5
+ Naturally Occurring Contamination from Wildlife, 6
Sidebar: A Taxonomic Headache, 7
Part 3 The Wastewater Treatment Debate: 9
Septic Tanks vs. Wastewater Treatment Plants
+ Septic Tanks, 9
+ Wastewater Treatment Plants, 11
Sidebar: Septic Systems for Dogs, 13
Part 4 Indicators Used to Detect 15
Bacterial Contamination in
+ Enterobacteriaceae, 16
+ Total coliforms, 18
+ Fecal coliforms, 19
+ Escherichia coli (E. coli), 20
Sidebar: Pseudomonas aeruginosa, 21
+ Enterococcus, 22
Sidebar: Other Indicators, 23
Part 5 Laboratory Methods for Counting 25
+ Membrane Filtration, 25
+ Most Probable Number, 25
+ Plate Counts, 26
+ Presence/Absence, 26
Sidebar: Which Laboratory Method Does
LAKEWATCH Use? 27
Part 6 Criteria for Assessing Coliform 29
Contamination in Florida Waters
Part 7 A Four Step Process for Identifying 31
and Locating Bacterial Contamination
+ The Good News
+ Step 1 Collect Samples from Multiple Sites, 32
+ Step 2 Identify Sites with Elevated Fecal
Coliform Counts, 32
+ Step 3 Test for E. coli and Look for False
+ Step 4 Re-sample Sites with Elevated Fecal
Coliform Counts, 34
Sidebar: Locations to Consider When Tracking
Possible Sources of Contamination, 35
Selected References, 38
When we think about bacteria, many of rivers, streams and oceans, where they serve as
us often think of pathogenic (disease- "decomposers," helping to break down dead
causing) organisms that are notorious plant and animal tissue and continually releasing
for causing illnesses in humans such as cholera, nutrients back into the water. For example,
tuberculosis, typhoid fever, etc. While admittedly, Cyanobacteria play a critical role in the photosyn-
these diseases can be quite serious, it is important thetic production that occurs within many
to recognize that the bacteria responsible for such aquatic ecosystems,2 while other bacteria are
illnesses represent a relatively small fraction of the crucial to important chemical processes in water
thousands of "species" that are known to exist. such as nitrogen fixation and denitrification.3
It also helps to keep things in perspective
by acknowledging that bacteria have been around Why the Concern?
for a very long time. In fact, fossil remains tell us Like most things in life, it only takes a few
that one group of bacteria, known as Cyanobacteria, troublemakers to spoil the fun. In this case,
was among the first life forms to have been health officials are mostly concerned about a
established on earth more than three billion years small number of bacteria strains that are enteric
ago. Some scientists even theorize that these (i.e., of or related to the intestines of warm-
organisms helped to create the earth's unique blooded animals, including humans), as well as
life-giving atmosphere by producing so much opportunistic viruses and protozoa that can cause
oxygen, via photosynthesis, that eventually the illness in people, particularly those with weakened
atmosphere became habitable for other creatures. immune systems.
Bacteria can be found in virtually every Bacterial contamination generally refers to
environment you can think of including air, soil, instances in which human or animal wastes are
and water. Some strains have even been found in found in concentrations greater than the receiving
volcanic vents and deep inside arctic ice flows- waters can handle (i.e., when the volume of
environments once thought to be barren of any water is not enough to dilute waste products to
life. However, bacteria are also found much an acceptable level). In such instances, humans
closer to home. Did you know that a single
teaspoon of topsoil is thought to contain more 2 Because cyanobacteria are aquatic and capable of
than a billion bacteria and one square centimeter making their ownfood via photosynthesis, they are
sometimes called blue-green algae.
of human skin holds an average of 100,000
bacteria cells! 3 Some bacteria are known to convert gaseous nitrogen
into nitrates or nitrites. The resulting products are released
a in L into the water, making impossible for some plants to capture
these nutrients. T process is known as nitrogen fixation.
Bacteria are a natural component of life in When bacteria metabolize nitrates and turn them into
all aquatic systems including freshwater lakes, nitrogen gas or nitrous oxide, it is known as denitrification.
drinking from, swimming in, or eating shellfish and can be even more difficult to detect. For
from a contaminated waterbody, run a greater example, an infectious dose for a virus is far
risk of being exposed to harmful bacteria or lower than that of bacteria-by at least one order
pathogenic viruses that may also be present. of magnitude (i.e., 1/10h of the concentration).
Because it is impossible to eliminate all harm- This means that detecting a virus in a waterbody
ful bacteria from aquatic environments, U.S. is akin to finding a microscopic-sized needle in a
government health agencies have set standards for haystack. Adding to the challenge is the fact that
acceptable levels allowed in public waters. some enteric viruses can remain infective for
several months in both sediments and water and
See Part 6 on page 29 for more on the criteria used tend to be somewhat resistant to disinfectants.
to assess coliform contamination of Florida waters.
Testing for protozoa can also be tricky as
These standards tend to be conservative and they are present in relatively low concentrations,
experience has shown that they are effective in even in polluted waters, and the number of organ-
preventing human health problems nearly all of isms can change quickly over time. Current
the time. However, even if risk levels may be methods for detection are not well standardized,
deemed acceptable, meeting the standard does so there has been a lack of consistency when it
not completely eliminate the possibility of comes to setting water safety standards for these
becoming sick. Along those same lines, just organisms. Because of the difficulties and the
because a bacterium enters a waterbody, it doesn't expense associated with this type of monitoring,
necessarily mean the risk of contracting a disease most efforts have been limited to work being
is increased. It simply means that there is the conducted by researchers, as opposed to public
potential for a problem. health agencies. However, if epidemiological
evidence indicates that sampling is needed, some
Viruses and Protozoa in Water public health organizations are equipped to do
Bacteria are not the only microbial concern extensive and detailed sampling.
related to water usage. Pathogenic viruses and If you have questions regarding viruses or
protozoa such as amoebas may also be present protozoa, contact your public health department.
very summer, questions It's important to note that
surface about an aquatic swimmers who have contracted
amoeba (Naegleriafowleri) PAM usually got it after rooting
with a bad reputation. This around the lake bottom, in
organism is part of the larger heavy silt where the amoeba
protozoa group mentioned on lives. Therefore, keeping
page 2. Over the past 30 years, one's face away from the
there have been 34 deaths bottom of a lake, river, canal,
recorded in the United States etc. and keeping swimmers
due to exposure to this nasty from jumping off a dock into
little organism. Fifteen of the shallow water-or any other
deaths occurred in Florida. scenario that would result in
Fortunately, the chances of the disruption of bottom
coming in contact with sediments-will significantly
Naegleria, or contracting the reduce the risk of exposure to
resulting illness (Primary Naegleria. Young children are
Amoebic Meningoencephalitis- at the highest risk of exposure
PAM, for short) are quite slim. as they tend to engage in
In Florida, health officials such activities.
estimate that there is only one case for every 2.5 Everyone can be further protected by wearing ear
million hours that people spend in freshwater. Drown- plugs and a nose clip (or a dive mask that covers the
ing and boating accidents pose a much greater threat nose) when swimming. Remember, exposure to
to our state's water enthusiasts. With that said, there bottom sediments is the single MOST important
are a few precautions swimmers can take to decrease factor that increases chances for infection.
their chances of exposure even more. During most of the year, concentrations of
The first thing you should know is that, with the Naegleria are rarely high enough to cause public
exception of Antarctica, this amoeba is believed to health problems. However, as water temperatures
exist in virtually every lake and river around the rise during the summer (82-86 degrees Farenheit), it
world. It is also found in spas, hot tubs, thermally provides a more accommodating environment for the
enriched waters and poorly chlorinated swimming amoeba to feed and multiply. So, if possible, avoid
pools. So, if you're thinking of simply avoiding these swimming in warm shallow waters during this time.
aquatic environments, you might get a little lonely.
So, How Does One Avoid the Amoeba? Early diagnosis is the best bet for survival. In the
The best way to prevent exposure to Naegleria is to two known cases where patients survived infection
avoid stirring up bottom sediments, as this is where the from Naegleria, the family doctor recognized the
amoeba lives and feeds on bottom sediments composed symptoms immediately and was quick to react with
of fallen leaves and dead plants. Once sediments are appropriate antibiotics. Persons who complain of
mixed into the water column, the amoeba could be severe headaches, rigidity of the neck, impaired
forced up the nose of a swimmer who jumps or falls sense of smell and taste, nausea, vomiting and/or a
into the water. This increases the chance for it to high fever, and who have been swimming in a lake
enter into an ear or nasal passage where it can should be taken to a doctor. If the treatment is going
follow the olfactory nerve and gain entry into the to be effective, it needs to be administered quickly.
brain, where it has been known to cause problems. Note: You cannot get PAM by eating fshfrom a lake.
0) r15"3 ~
s --~a~ T~IC
T here are numerous potential sources of disease-causing bacteria from wastewater
bacterial contamination in Florida lakes discharges (often greater than 99.9% of the
-and other lakes, for that matter. In a time). However, there is still a risk that a pathogen
booklet such as this, it's impractical to list every or virus could be released in the water discharged
one of them. However, they can be grouped into from the treatment plant.
three general categories: human waste, domestic In rural and suburban areas of Florida, septic
animal waste, and naturally occurring contamina- tanks are the most common treatment system
tion from wildlife. Of course, contamination can used for human waste. However, despite their
also result from a combination of sources. prevalent use, septic tanks are often maligned
when issues of nutrient enrichment and bacterial
Human Waste contamination are discussed among lake users.
The disposal of untreated human waste into This is unfortunate because, while there is
the nearest waterbody was once a common certainly evidence that septic tanks can add
practice throughout the world, including the nutrients and bacteria to lakes, the contribution is
United States. Even as recently as the mid-20th usually not as great as many people think.
century, it was common practice for U.S. cities
See Part 3 The Wastewater Treatment Debate
and towns to discharge untreated human waste page 9.
into rivers, streams, lakes, or oceans. For years,
dilution was considered to be the "solution to Domestic Animal Waste
pollution." This practice is no longer condoned The improper disposal of human waste is not
and now, there are legal requirements for the the only possible source of bacterial contamination.
treatment of human wastes. Domesticated animals are warm-blooded and
In less developed countries, some communities their wastes can, at times, harbor pathogens known
continue to discharge both human and animal to adversely affect humans. So, unmanaged storm-
wastes into local waters. This is not always a water runoff from sites with high concentrations
problem if the amount of waste is small relative of domesticated animals such as animal feedlots,
to the volume of the receiving water. In some cattle and pig grow-out operations, etc. can also
instances, wastes are used as fertilizers for be potential sources for bacterial contamination.
terrestrial crops and/or even as fish food for Given the high visibility of these facilities, and
aquaculture crops. the odors they tend to emit, it's natural for area
In developed countries where more finan- residents to point to these areas first when
cial resources are available, large municipal bacterial contamination issues arise. However,
wastewater treatment plants are used to treat large such operations are not always to blame and
volumes of human waste. These types of treatment bacterial testing must be conducted before any
plants are extremely effective at removing conclusions are made.
Domesticated animals living on open Naturally Occurring Contamination
rangeland or pastureland, such as cattle or from Wildlife
horses, can also contribute to high bacteria When issues of bacterial contamination
counts in lakes and waterbodies. Often the occur at a lake, the focus almost immediately
contamination is related to the animals entering turns to sources such as septic tanks, runoff from
the water for drinking or cooling purposes, and livestock holding pens, or leaky sewer lines.
then defecating directly into the water. This can While these should always be considered, it
be corrected relatively easily by fencing the should also be remembered that there are natu-
animals away from the water. rally occurring sources of bacteria. For example,
However, the animals will then need to be large concentrations of wildlife such as deer or
provided drinking and cooling water, which can birds represent a significant potential source for
be expensive. In these bacterial contamination of a
situations, the problem, and waterbody.
resulting tensions among If bacterial contamination is A case in point is the
neighbors, can sometimes be suspected, bacterial testing bacterial contamination
resolved more quickly if the is a good first step to try and problem that occurred at
effected community is willing locate the sourcess. Lake Fairview in Orlando,
to assist the landowners) in Florida. It was originally
obtaining financing that will See Part 7 on pages 31-35 thought that the contamina-
help correct the problem. for a step-by-step approach tion was due to leaky septic
Perhaps the most to determining if bacterial tanks. This resulted in
pervasive problem associated contamination has occurred discussions concerning the
with domesticated animals is in a waterbody need for a municipal water
the runoff that follows heavy treatment plant. However,
rains. This is often referred after an extensive bacterial
to as "non-point source" study, it was determined that
runoff. However, it must be remembered that this the source of contamination could be traced to
source of contamination is not solely limited to bird droppings from large numbers of seagulls
agricultural lands. In urban areas, contaminated that were using the lake. Apparently, the seagulls
stormwater runoff is believed to originate from were feeding at a nearby landfill during the day
animal waste generated by pets, particularly in and then congregating at Lake Fairview to roost
parks where people bring their pets to exercise. each evening.
This type of non-point source runoff is An observant biologist happened to notice
difficult to control. In some areas, attempts are that when the seagulls were absent, there was no
being made to reduce the problem by preventing contamination. In this instance, it's evident that
the direct flow of stormwater into a waterbody. eliminating septic tanks would not have solved
Swales (a shallow depression in the landscape), the bacterial contamination problem as it was
man-made wetlands, and stormwater retention essentially a natural phenomenon that was
ponds are a few of the methods that have been difficult to control. It is also a good lesson for
widely used in recent years. However, because those who may balk at the expense of additional
use of such techniques is not always possible, the bacterial sampling for a lake or waterbody. In the
safest approach is to avoid recreational activities case of Lake Fairview, the cost of the extra
in your neighborhood lake for two to three days sampling paled in comparison to the cost of a
following exceptionally heavy rainfall. While it new wastewater treatment plant and expenses
may not eliminate the possibility of contracting associated with long-term maintenance of the
an illness, it can reduce the probability, plant and its sewage collection pipes.
One of the problems related to the study of bacteria is the difficulty in isolating and
describing the thousands of organisms that exist. It's hard enough to locate and
identify insects, birds and mammals; imagine working with microscopic
organisms, many of which have a half-life* of one hour!
So how does one differentiate between different types
Classification by shape and/or structure is one way.
Fortunately for us, bacteria are essentially limited
to three basic shapes:
+ Rod or stick-shaped bacteria are referred to as bacilli Esherichia coli (0157:H7)
+ Sphere shaped bacteria are classified as cocci
(pronounced cox-eye); and
+ Spiral shaped bacteria are classified as borrelia
Some live as individual cells while others tend to
group into pairs, chains, squares or other configurations. Staphylococcus aureus
on human skin
The composition of a bacteria's cellular wall is also an
important defining characteristic: Gram positive bacteria
have multi-layered cell walls, while gram negative bacteria
tend to have much thinner cell walls.
Adding to the challenge
Recent advances in microbial research are presenting another 8
dilemma. Thanks to new information gained from DNA and RNA Leptospira interrogans 2
sequencing, many bacteria are being renamed and/or re-classified. spirall shaped prokaryote)
As a result, many old lengthy complicated names are being changed
to new lengthy complicated names. This can be quite confusing, as many
of these outdated references are still in use.
If you should find that the science has indeed gotten ahead of this publication, please
don't hesitate to let us know! And remember, your questions and comments are always ,
welcome. Call Florida LAKEWATCH at 1-800-LAKEWATCH (1-800-525-3928). g
* Half-life the time required for half of the atoms of a substance/organism to disintegrate. E
There can be no doubt that advances in
wastewater treatment over the last 50 A septic system is a self-contained,
years have contributed greatly to the underground wastewater treatment system
reduction in waterborne illnesses. With this great that uses natural processes to treat and
success, one might wonder why we're not dispose of wastewater. These systems are
treating all human waste with advanced treat- also referred to as onsite or decentralized
ment processes and why opposition to upgrading wastewater systems.
existing wastewater plants always seems to
S. Septic systems are simple in design, consist-
emerge during public discussion. The following
ing of two main components-a watertight
is a brief overview of the on-going debate,
tank and a drainfield.
including some of the advantages and disadvan-
tages associated with each system. The tank is usually made of concrete or
fiberglass, with an inlet and outlet pipe.
Septic Tanks Wastewater from the home or building flows to
The septic tank is the most common waste- the inlet pipe and septic tank through a sewer
water treatment system in many rural and suburban pipe. Once inside the tank, the wastewater
areas of Florida. Yet despite its prevalent use, it eventually separates, forming three layers.
is often maligned among lake communities when Solids that are lighter than water, such as
issues of nutrient enrichment eutrophicationn) greases and oils, float to the top while solids
and bacterial contamination are discussed. heavier than water settle to the bottom, leaving
Certainly, there is evidence that septic tanks a middle layer of partially clarified wastewater.
can add nutrients and bacteria to lakes, but the
,. Naturally occurring bacteria that live in the
contribution of these materials to local waters is
Sn a g a wastewater continually work to break down the
usually not as great as many people think.
Properly functioning septic tanks generally solids. Any sludge that cannot be broken down
Properly functioning septic tanks generally
is retained in the tank until the tank is pumped.
contribute only small amounts of nutrients, if at
all. In fact, some long-term lake studies have The middle layer of clarified liquid flows from
suggested that septic tanks may have only a the tank via the outlet pipe to the drainfield,
limited impact on nutrient levels in most lakes. which usually consists of a series of pipes
The same seems to be true regarding the issue of placed in trenches lined with gravel or course
bacterial contamination, but each situation must sand. The drainfield treats the wastewater by
be examined carefully. allowing it to slowly trickle from the pipes into
Failed septic systems are primarily associated the gravel and down through the soil, which
with effluent leakage to the soil's surface from serves as a biological filter.
the drainfield and are usually detectable by
smell. As a general rule, if you elevated drainage field mounds have been known
can smell waste, there is most to leak through the sides. For that matter, well-
likely a problem that needs to be constructed elevated drainage fields have had
addressed quickly. If there is leakage problems. Therefore, even the newer
leakage, it tends to be near systems should be carefully examined for potential
the ends of the drainage field or problems.
sometimes it's due to the lack of Admittedly, there is no perfect septic disposal
soil over the drainage area. In these situations, system and there probably never will be. How-
wastewater is subject to being washed to a nearby ever, the failure of one septic system should
lake via surface water runoff. Fortunately, this not be used to condemn this method of waste
type of problem can be easily fixed by importing treatment. Expensive municipal wastewater
more soil and covering the area. treatment plants have problems of their own.
In other instances, leakage is due to the See pages 11-12 for more information
drainage field becoming clogged over time. This on municipal wastewater treatment plants.
can be remedied by providing a new field or expand-
ing the existing field. Homeowners often balk at
this solution because it is expensive, but health
concerns should override any monetary concerns.
There may also be times when solid waste
will need to be pumped from the septic tank -
itself. This is usually dependent on the amount of "
wastewater generated, based on the number of
people using the system and the amount of water
used. Kitchen garbage disposals, for example, are
infamous for increasing the amount of solids in a
septic tank, making it more difficult for bacteria
to do their job of breaking down the waste.
In the 21st century, homeowners now have a In 1997, the US EPA reported that "adequately
t century, homeowners now have a managed decentralized wastewater systems
choice between below-ground septic tank systems (i.e., septic tanks) are a cost-effective and long-
or above-ground systems. While the below-ground term option for meeting public health and water
type may seem risky for lakefront communities, quality goals, particularly in less densely
there are systems that are specially designed for populated areas." The agency also recognized
waterfront property. The tanks are setback consid- that poor septic tank management is a major
erably from the lake shoreline to minimize the part of the problems and/or criticisms associ-
possibility of untreated waste or nutrients entering ated with these systems. As a result, in 1998
the lake as seepage or runoff. If maintained the EPA was challenged to produce a set of
properly, they can provide reliable cost-effective voluntary national management standards for
wastewater treatment for years. citizens to follow. These guidelines are available
Above-ground septic tanks are becoming in the EPA publication entitled Onsite Waste-
popular in low-lying areas where soils remain a te r rea tment systems anua
wet for prolonged periods of time. When working 625R 00008). Free copies can be ordered by
wetcalling 800-490-9198. For more information,
properly, they are considered to be quite effective ch o e E wbie
check out the EPA website:
at treating wastewater. Some people believe
these new elevated above-ground septic systems http://www.epa.gov/owmitnet/mtb/
are better than the in-ground versions. This is a decent/summary.htm
dangerous assumption as improperly constructed
Wastewater Treatment Plants can have on a community; they are expensive to
Perhaps the strongest argument in favor of build and to operate. And while government
wastewater treatment plants is their effective- grants are often available for the construction of
ness. Today's advanced treatment processes are the plants, the cost of properly maintaining
about 99.9% effective in removing pathogens these systems for the long haul is borne by the
from wastewater. However, their effectiveness community. This means that any community
during normal operation should not always be contemplating the construction of a wastewater
the primary focus of concern. There are other treatment system must be prepared to expend
issues that should also be considered. significant amounts of money on maintenance
One major concern for Floridians should be for both the treatment plant and its collection
the potential for complete disruption of services system. If long-term expenses are overlooked,
during natural disasters, such as hurricanes, problems often become apparent years after the
During these periods, the public is asked to avoid construction of a wastewater treatment plant
contaminated water and be patient until services when bacterial contamination is discovered in a
are restored. Depending on the problem, this can nearby lake or in the groundwater.
sometimes take weeks. (Parents should be After many meetings and expensive upgrades
especially vigilant to keep children from playing are made to the main treatment facility, some
or swimming in potentially contaminated water communities are surprised to find that the source
following such storm events.) of contamination still may not have been eliminated.
Another point of contention relates to the Instead, the problem could very well be within
financial burden that wastewater treatment plants the collection system-miles and miles of sewer
pipes that, when deteriorated, can begin to release even been speculated that aging wastewater
small amounts of untreated waste. When this collection systems (sewer pipes, etc.) represent
happens, additional capital will be needed to pay the greatest threat of fecal contamination to
for the upgrade or repairs. lakes-even more than septic tanks.
There is another aspect concerning the Sometimes extensive monitoring is necessary
construction of new wastewater treatment plants to determine if waste is leaking into a local water-
that many people don't think about. While citizens body or the groundwater supply. Fortunately,
may be anxious to modernize their community's there are several methods that have been developed
sewage treatment facilities, they may not realize in recent years that make this task a little easier.
that by building a new system or expanding an Lastly, it's important to remember that no
existing one, they might also be opening the door human invention is foolproof. All wastewater
to the dramatic development of an area, includ- treatment plants can experience failures in treat-
ing an increase in the local population. If septic ment processes. When severe failures do occur,
systems are suspected sources of bacterial wastewater plant operators must release untreated
contamination, one might first assess the cost of wastes to the nearest waterbody because they
improving those systems before jumping on the cannot treat the waste or they risk damage to a
wastewater treatment plant bandwagon. section of the treatment plant. This doesn't occur
As with septic systems, municipal wastewater often, but it will most likely occur at some time
systems also have a limited life expectancy and during a plant's history.
must be maintained and repaired constantly to
ti. e ctine and See Part 7 on pages 31-35 for more on identifying
retain their effectiveness and integrity. It has suspected sources of contamination.
Wastewater treatment plants are centrally
located facilities, usually built and operated by city
or county municipalities and are primarily designed
to do one thing: Remove harmful pollutants from
domestic and industrial liquid waste so that it is safe
'r. to return to the environment. This is accomplished
by pumping wastewater from private homes or
businesses through many miles of sewer pipes to
waste treatment plants. It is then pumped through a
series of treatment processes to remove unwanted
materials and chemicals.
The removal of harmful materials, including
micro-organisms, is accomplished with strictly
regulated control processes and specialized
equipment such as control pumps, valves, etc.
Once the wastewater is treated, it is returned to
streams, rivers, and oceans, or re-used as "gray
water" to irrigate landscaping. Industrial facilities
sending waste to municipal treatment plants must
meet certain minimum standards to ensure that
wastes have been adequately pretreated and will
not damage municipal treatment facilities. Waste
from private homes is currently not regulated.
Septic Systems for Dogs (WhatWill They Think of Next?)
W ith the increasing popularity of dog parks around the nation, concern about surface runoff
from doggie waste has also cropped up. Some park planners are thinking ahead by
incorporating waste treatment systems into their plans. Underground septic tanks located at the
parks are used to prevent seepage into low-lying areas or possibly into nearby streams or lakes.
Pet owners are asked to collect pet waste and deposit it into clean-up stations located throughout
the park; the waste is ultimately disposed of via the septic system. According to estimates, septic
tanks only need to be pumped out once a year or on an as-needed basis. The system costs
about $700, and is reimbursed from annual fees paid by park users.
D detecting pathogenic bacteria and viruses reliable indicators that fecal waste may be present;
in water can be a challenging endeavor. .
in water can be a challenging endeav. They tend to live longer and are found in
Even with today's advances in microbiol-
Sgreater numbers than pathogens, making them
ogy, it is extremely difficult and expensive to i
easier to detect in a laboratory sample;
isolate specific organisms. Some species are
rarely found in large enough numbers for detection, + They are generally non-pathogenic and there-
while others are nearly impossible to cultivate in fore less risky to deal with when collecting
a laboratory as they require just the right combina- samples and analyzing in a laboratory; and
tion of environmental conditions to grow.
tion of environmental conditions to grow. Laboratory methods used for detecting and
So, instead of trying to identify elusive
Counting these organisms are relatively simple
pathogens in a water sample, nearly all monitoring
programs test for the presence of non-pathogenic
bacteria that are far more numerous and easier to Continue reading the rest of this section to
detect. This approach is based on the theory that learn more about the Enterobacteriaceae family,
if certain non-harmful indicator organisms are total coliforms, and fecal coliforms. Learn why
present in a water sample, then harmful bacteria they may or may not be appropriate indicators
or viruses may also be present. The concept was for specific bacterial contamination concerns.
introduced in 1892 and continues to be the basis Also, learn about other bacteria groups, includ-
for most water quality standards today. ing the Enterococcus family, that are being
For many years, public health agencies have considered for use as indicator organisms.
largely relied upon the presence of two coliform
bacteria groups, total coliforms and fecal
coliforms, as indicators of bacterial contamina- The indicator organisms discussed in this
tion in water. As you can see in Figure 4-1 on circular are primarily used for the detection of
page 16, coliforms are classified as two sub- bacteria in "non-potable" waters waters
groups of the Enterobacteriaceae family intended for swimming or bathing. While several
(pronounced Enter-o-bac-teer-ee-a-see-ay). Their of the same organisms may be used for monitor-
classification within this family means that, aside ing potable (drinking) water or even wastewater,
from their genetic similarities, coliform bacteria there may be some variation, more than we have
share several common traits that make them room for in this publication. For more information
useful indicator organisms, including: about monitoring criteria and techniques used for
detecting bacteria in drinking water or waste-
* Many of these organisms are known to exist in water, please refer to the Selected References
the intestines and feces of warm-blooded animals, section in the back of this publication.
including humans, and therefore serve as fairly
s scientific names go, the word of water. The tests are commonly referred to as
Enterobacteriaceae is a definite tongue- total coliform counts and fecal coliform counts.
twister. However, it's really not as hard Traditionally, health officials using these
to decipher as one might think. One helpful hint counts have assumed that if high numbers of
is the prefix entero which tells us that these coliforms are detected in a water sample, then
bacteria are enteric-of or relating to the intestines, recent fecal contamination is present and repre-
Also, its lengthy name is certainly appropriate as sents a health threat. (Remember the theory: if
this family represents an expansive group of indicator organisms are present in a water sample,
organisms that includes nearly a dozen separate disease-causing bacteria or viruses may also be
genus groups and more than 40 "species." present.)
See Figure 4-1 for a general idea of the hierarchy Years ago, when many U.S. cities and towns
of the Enterobacteriaceae family, were discharging untreated waste into public
Fortunately for us, there are only a few waters, this assumption was most likely correct.
Fortunately for us, there are only a few
groups within this family that we need to know
for bacterial monitoring purposes:
+ The larger total coliform group includes
many different species and strains of coliform
bacteria, originating from a variety of sources coliformgro
(i.e., fecal and non-fecal) including both plants
and animals. Eherichia s
* The fecal coliform group includes bacteria ebsieas
that usually originate from fecal matter (i.e., Ci-obacter
animal or human waste).
* Escherichia coli (E. coli)5 is just one of the
many types of bacteria within the fecal coliform
group. This "species" has recently surfaced as a
particularly useful indicator organism.
For years, most public health agencies
Bacteria within the Enterobacteriaceae
largely depended on the first two groups, total
family belong to at least four genera4:
and fecal coliforms, as indicators for detecting faily belo to at least or eera
Escherichia, Citrobacter, Klebsiella, and
potential bacterial contamination. Why? Enterobacter. Within these groups, there are
Ease of testing is one reason. Because these many different "species" and/or strains-far
groups include a broad spectrum of closely too many to list here.
related organisms, scientists were able to develop
.- 14 The term genera is plural for genus. A genus is
a fairly simple testing method for estimating the .
comprised of one or more species and is one of the
number of coliform bacteria colonies in a volume primary ranking categories used for classifying living
organisms within the animal kingdom. An organism's
5 The strains ofE. coli discussed in this circular are not genus name helps to rank it within the larger family
the same as those associated with cases of severe food group, but is still one level above its "species" name.
However, now that the vast majority of
municipalities have wastewater treatment
plants-effectively eliminating most major health i
threats-total and fecal coliform counts are no
longer considered to be as useful. (i.e., They are not
considered "sensitive" enough for detecting
small amounts of bacteria.) In fact, the U.S.
Environmental Protection Agency (U.S. EPA)
and many state health agencies are now recom-
mending that total and fecal coliform tests be
phased out and replaced with E. coli tests.
For the time being however, it's important
to remember that fecal and total coliform counts
remain the legal standard for Florida waters.
These standards continue to be used for several
(1) They are the least expensive tests to perform;
(2) They are commonly used as water safety
criteria in many state legal standards;
( n Jennifer Donze, with Florida LAKEWATCH, places
(3) They can provide valuable clues on what is
eally n i te lake o tebody bacteria samples into an incubator where they will
really going on in the lake or waterbody.
"bake" for 24 hours. After incubation, samples are
As you will learn from reading the rest of observed and bacteria colonies counted. LAKE-
this section, there are a few drawbacks related to WATCH has been monitoring bacteria for survey
the use of total and fecal coliform counts. However, purposes, on a limited number of lakes, since the
they still provide a good screening mechanism to year 2000. Total coliform counts, fecal coliform counts
begin with if bacterial contamination is suspected and E. coli counts have been the bacteria testing
in a waterbody. If one does find high total and methods of choice for the survey.
fecal coliform counts, steps can then be made to
investigate further, perhaps using other indicator
organisms and tests. For years, many state governments,
If you are deciding whether to do the testing including Florida, have come to rely on
yourself or hire a private laboratory, equipment
requirements will undoubtedly be a major factor.
Many testing methods require the use of an incuba- detection of bacterial contamination.
tor, an autoclave (for sterilizing) and membrane Many have enacted legislation estab-
filtration devices-all of which involve a large lishing numerical bacteria standards or
initial investment. However, once the equipment guidelines for determining if a water-
is obtained, routine testing is fairly inexpensive, body is "safe" for recreational activities.
especially if water samples are collected by See page 29 for the current Florida
volunteers. standards, but also remember to
The good news is there are several compa-
nies working to develop reliable bacteria detec-
tion methods that involve less equipment and are in the near future.
easier to use. So stay tuned.
Total Coliforms high-tech incubators is certainly preferred.
As an indicator, total coliform counts are
most effective at red-flagging contamination in
T he term total coliforms drinking water. World Health Organization
refers to a numerical count guide-lines for drinking water allows a maximum
of the total number of coliform of 0-2 organisms per 100 mL as acceptable for
bacteria that exist in a measured piped water supplies and a maximum of 10 per
amount of water (i.e., from a sample). 100 mL for unpiped water supplies. It also states
This count generally includes both fecal and that "frequent occurrences of high coliform counts
non-fecal coliforms and an expansive assemblage signify the need for an alternative water source or
of closely related organisms within the Entero- sanitary protection of the current source." 6
bacteriaceae family. When using total coliform counts as an
See Figure 4-1. indicator of contamination in recreational waters,
remember that even though coliforms are found
For years, total coliform counts have been in fecal waste, there are other bacteria within the
considered tried-and-true indicators of bacterial same group that naturally occur in aquatic plants
contamination, mainly because they include and soils. Because of this, high total coliform
fecal coliforms, which tend to be more prevalent counts cannot always be considered an indicator
and longer-lasting than the elusive pathogens of fecal contamination. It's also the reason why
that sometimes co-exist in fecal waste, total coliform counts are no longer considered as
Also, their ability to carry out lactose useful for determining the safety of recreational
fermentation at fairly low temperatures (95-97 swimming or the consumption of shellfish.
degrees F) makes it relatively easy and inexpen-
Does this mean that total coliform counts should
sive to process samples in a laboratory: Samples indicators?
no longer be used as indicators?
are incubated to "trigger" a fermentation process,
which causes coliform bacteria to grow. Once Not necessarily. While high total coliform
growth has occurred, colonies can be counted. counts may not always be an indication of fecal
For those with a limited budget, a sampling contamination in a waterbody, they may still be
method that can be achieved without expensive an indication of a potential health risk. For
example, high total coliforms may sometimes
indicate the presence of plant material and an
associated bacteria known as Pseudomonas
aeruginosa. This bacteria is considered to be
non-fecal in origin and, therefore, unlikely to
--- -. pose any severe health threats. However, it is
Known to be a major cause of ear infections in
humans and is also associated with skin rashes.
So, even if a lake shows no sign of fecal
contamination, a high total coliform count could
indicate a potential risk for swimmers, water
skiers, or others that come in contact with the
water for a prolonged period of time.
". See page 21 for more on Pseudomonas aeruginosa.
6 Hach Company. 2000. The Use of Indicator Organisms
to Assess Public Water .' Technical I
Series Booklet No. 13.
fecal coliform counts is the fact that these counts
Fecal Coliforms do not seem to correlate with the incidences of
gastrointestinal illness experienced or reported
s illustrated in Figure 4-1, by individuals using recreational waters.
1A fecal coliforms are a sub-
of tal coliforms. arey are s- ~ Does this mean that fecal coliforms should no
set of total coliforms. They are longer be used as indicators?
also the group of bacteria that, "
from a huan heath perspective, Again, not necessarily. Many public health
from a human health perspective,
eoe ae m t ccerned a bec e tey agencies continue to use fecal coliform counts as
people are most concerned about because they
. indicator bacteria. Legal standards are one
indicate the presence of fecal matter in a
waterbody reason; a large number of states, including
W n c rin t e iv Florida, still rely on long-standing fecal coliform
When comparing the effectiveness of total
criteria to set the legal limits for water quality
coliform counts versus fecal coliform counts, it
1. and safety. In many instances new standards or
could be said that fecal coliform counts are and safety. In many instances new standards or
., criteria have yet to be developed for several of
considered to be a more reliable indicator of criteria have yet to be developed for several of
contam n w n a w y. the newer indicator organisms, including E. coli.
possible contamination within a waterbody.
i So, even if new indicator organisms are
Use of this test has long been based on two
assumptions: added to the testing regimen, fecal coliform tests
still have to be used to meet the existing legal
(1) Fecal coliforms originate only from warm- standards. Also, some groups have decided to
blooded animals; and continue fecal coliform counts in their testing
regimen so that current data can be directly
(2) Fecal coliforms do not survive for an extended regimen so that current data can be directly
Scccompared with historical data, which usually
period of time in water and are, therefore, fairly compared with historical data, which usually
consists of fecal coliform measurements.
reliable indicators of recent contamination. consists of fecal coliform measurements.
When dealing with large-scale human
contamination from untreated wastes or an
inoperative wastewater plant, these assumptions
are typically true. However, they've also become
dogma among many public health workers, even
when studies have shown otherwise. For instance,
several studies now show that fecal coliform
counts sometimes include bacteria that are not
necessarily fecal in origin. An example is the
free-living strain of the Klebsiella bacteria that is
often present in soils.
The presence of such organisms in a fecal
coliform count can result in false positive read-
ings. In other words, the test results will suggest
fecal contamination, when there is none. Studies
have also definitively shown that fecal coliforms J
can survive and even multiply in the natural _
environment, therefore their presence does not --
necessarily indicate contamination from an
Perhaps the strongest criticism related to
There seems to be a correlation between the pres-
Escherichia coli (E. coli)
ence of E. coli and swimming-related illnesses.
E scherichia coli (E. coli) Note: Admittedly, this can be somewhat c, f(,,;i,,;
bacteria represent a sub- even though the indicator strain ofE. coli is
Considered to be harmless, it can sometimes be
group within the fecal coliform
group. (See Figure 4-1.) Amazingly, accompanied by the toxic strain (0157:H7) and
even within this smaller E. coli other organisms that can cause illness.
bacteria group, there are hundreds, perhaps Does this mean that E. coli bacteria should
thousands, of different strains. Although most always be used as indicator organisms?
strains are harmless and live in the intestines of Not necessarily. The methods used for
healthy humans and animals, there are a few detecting E. coli do have a few drawbacks:
known to cause problems. For example, many of
Some methods involve two incubation steps,
us have heard rather alarming reports about E. coli m
., making it more time-consuming and expensive
0157:H7, a strain associated with an estimated an t oe teconumin n n
7i 7 than total and fecal coliform counts.
73,000 cases of food-borne illness each year.7
This deadly organism is different from the E. coli + When counting colonies of E. coli bacteria in
used as an indicator for water quality, a laboratory sample, there are times when other
Use of the "harmless" E. coli strain as an naturally occurring bacteria, belonging to the
indicator organism has advantages over fecal group Klebsiella, may be present and inadvertently
coliform counts: counted along with the E. coli.9 This can result in
false positives. There is also the chance that E. coli
(1) It occurs only in the feces of warm-blooded
counts may be elevated due to the presence of
mammals and is therefore a good indicator of the
c bird feces.
presence of fecal waste in water;8 bird feces.
When any of these scenarios occur, additional
(2) EPA studies have shown that, in fresh water, steps are required to definitively demonstrate that
the vast majority of detected coliforms are, in
fact, E. coli. Even with these drawbacks, the EPA
is now recommending that public health agencies
regularly use the E. coli test when monitoring for
7 From the Center for Disease Control: The combination
of letters and numbers in the name of the E. coli bacterium
refers to the "' markers found on its ". and
distinguishes it from other types of E. coli. Other known
St sources of from E-coli 0157:H7 include the
Consumption of sprouts, lettuce, salami, unpasteurized
Sand juice, and swimming in or drinking sewage-
Wetemhile researching testing methods, you may run .
A hilhe researching testing methods, you may run 8 Similar to the total and fecal indicator approach,
across the phrase "EPA Approved." It is important E. coli testing is based on the assumption that if E. coli
to note that just because a testing method is EPA approved, bacteria are found in a waterbody, there is the chance
it does not necessarily mean that it is adopted by your that pathogenic bacteria or viruses may also be present.
local public health organization. If your purpose is to
9 Klebsiella pneumoniae is a naturally occurring free-
determine if a sample meets state legal water safety living soil bacterium that can also be found in the human
standards, you need to check with your local health
gut shortly after birth. There is no evidence to
organization before deciding which method to use. that this species has caused healthy individuals to
experience illness due to exposure.
In addition to the indicator organisms mentioned in this section, a bacteria
known as Pseudomonas aeruginosa (abbreviated P. aeruginosa often shows
up incidentally in total coliform counts, even though it is not a coliform.
This bacterium can be found almost everywhere in nature and in some man-
made environments, including the garden hose in your back yard. In lakes,
P. aeruginosa is often found as a naturally occurring bacteria within aquatic
plant communities and in the surrounding soils.
According to an informational bulletin published by the Hach Company,10
a standard laboratory method has tentatively been accepted for P. aeruginosa
testing. While it is not considered to be a particularly useful indicator of fecal
contamination (i.e., it is rarely found in the feces of healthy humans and
seldom isolated from animal feces), it can be useful for monitoring bathing
beaches. This is because P. aeruginosa has been known to be a major cause
of skin rashes and ear infections in swimmers and bathers.
10 Hach Company. 2000. The Use of Indicator Organisms to Assess Public Water ". Technical
I Series Booklet No. 13. Page 26.
A s we enter the 21st century, an entirely In tropical regions, some of these organisms
different group of bacteria, belonging to the are commonly found in unpolluted waters,
Enterococcus family are now being considered making them less reliable indicators of fecal
as indicator organisms (plural: Enterococci, contamination. This may apply to Florida waters,
pronounced enter-o-cox-eye). so caution should be used before this method is
Previously known as group D streptococcus, selected over the total and fecal coliform tests
Enterococcus bacteria represent an entirely presently used.
different strain of bacteria from the Enterobacte- Within the Enterococcus group, chemists
riaceae family. Because of their hardy nature, generally agree there are two main species that
these bacteria occur naturally in almost every hold the most potential as bacterial indicators:
environment including soil, plants, water, and Enterococcusfaecalis and Enterococcusfaecium
also within the gastrointestinal tract of many (formerly known as Streptococcusfaecalis and
animals and birds. They have even been found in Streptococcusfaecium, respectively). These species
various food products such as cheese, raw and occur in large numbers in both human and animal
pasteurized milk, frozen seafood, frozen fruits, feces and are thought to be appropriate indicators
fruit juices, and vegetables, for determining the presence of fecal contamina-
Prior to 1984, Enterococci bacteria were tion in a waterbody.
grouped within the fecal Streptococcus genus It should be noted however, that two other
and were often referred to as "fecal streps" by bacteria within the same genus, Enterococcus
bacteriologists. However, with recent advances avium and Enterococcus gallinarium (formerly
in genetics, microbiologists have found that known as Streptococcus avium and Streptococcus
certain bacteria within the fecal Streptococcus gallinarium, respectively), have been known to
group were genetically unique enough to classify pose health problems, even though they are
them as a separate genus.11 As a result, approxi- primarily associated with bird feces.
mately 17 different bacteria have been identified Until recently, the greatest hurdle in using
within this new Enterococcus group.12 Enterococci as bacterial indicators was the
Enterococci as bacterial indicators lack of reliable testing methods. This has
Recently, many professionals have come to changed with the development and (EPA)
consider the Enterococcus bacteria group as one approval of a new mE culturing medium. While
of the preferred indicators of fecal contamination the process is similar to fecal coliform tests,13
there are drawbacks: the medium used to test
from warm-blooded animals. This is true for at there are drawbacks: the medium used to test
least two reasons: for Enterococci is more expensive than me-
dium used for fecal coliform tests, and it
(1) In marine environments, Enterococci can contains a toxic ingredient.
survive longer than fecal coliforms, thus providing
a more accurate indication of the presence of
11 Richard R. Facklam and Sahm, D.F. 1995. Manual of
fecal waste; and .'Microbiology Page
C 'Microbiology. Page '
(2) Studies show a positive correlation between 12 Richard R. Facklam and Sahm, D.F 1995. Manual of
incidences of human gastrointestinal illness and C .'Microbiology. Pages. 309.
concentrations of Enterococci found in public 13 Enterococci require incubation at 410 C (106F).
waters. However, there is one exception.
W within the scientific community, there have imposed on most monitoring agencies. For now, it
been numerous discussions about using seems prudent to continue testing for total and fecal
bacteriophages (viruses that attack bacteria) or other coliforms, to eliminate the most probable and
bacteria as possible indicators of contamination, immediate health risk, and let the researchers worry
These organisms include coliphages, such as about detecting other organisms.
Bacterodesfragilis viruses, and F-Specific coliph- In addition to bacterial indicators, there are a few
ages, such as Staphylococcus aureus, Salmonella, chemical agents currently being considered as
S/1//I, Aeromonas, Campylobacterjejuni, and indicators of human fecal pollution:*
egionella. Detergents and optical brighteners are associated
Many of these have merit as potential indicator with laundry discharge and their presence in surface
organisms, but they also have major problems water may indicate an upstream source of waste-
when it comes to detection methods. For example, water from leaky septic tanks or sewer pipes.
some of the organisms are naturally occurring in
Coprostanol--a by-product of the bacterial
aquatic environments, which would make it difficult oroaol-a ro t the bac
to determine if there is an outside source of contami- breakdown of cholesterol in the human body.
nation. Additionally, the expense of detection and Caffeine.
the use of new DNA sequencing techniques often
Non-point Source News. Number 63. U.S. EPA, 2000
places these tests outside the budgetary constraints
Disposable "Whirl-Pak" bags are popular for The membrane filtration method involves
use in bacteria water sampling because they filtering samples through filters and incubating
don't require sterilization, them for a specified time and temperature.
Once filters have been incubated, coliform Rebecca Varner counts bacteria for Florida
bacteria colonies are then identified and LAKEWATCH's statewide bacteria survey
counted based on their coloration. project.
n addition to learning about indicator bacteria, placed on an appropriate agar medium or a pad
described on pages 15-23, it's also helpful saturated with a special broth medium, and then
to know a little about the laboratory methods incubated. If the targeted organism is present,
used for detection. The information may come in colonies will grow. Filters are then examined and
handy when trying to decide which method to bacteria are identified by size, color, shape and
use for bacterial monitoring. There are several sheen. Because bacteria colonies grow from a
variations, including: single bacteria cell, the number of colonies
SMembre F n ( ) present is considered to be representative of the
* Membrane Filtration (MF)
number of bacteria present in the water sample.
+ Most Probable Number (MPN) Results are usually reported as the number
+ Plate Counts of colony forming units per 100 mL (CFUs/100
mL). This method is one of the easiest, least
+ Presence/Absence (P/A) expensive methods for counting total coliforms.
Each of these methods generally involves
the use of an incubator14 as well as specific Most Probable Number (MPN)
media (i.e., agars or broth) designed for sup- The Most Probable Number (MPN) method
porting the growth of the targeted bacteria, usually involves 10-15 test tubes that are prepared
while inhibiting the growth of others. The with different amounts of bacteria growth medium
following pages provide brief descriptions of and sample water. The medium is designed to
each method, with an emphasis on the two support only the growth of a targeted bacteria
techniques most widely used in lake monitoring species.15 Once the test tubes are "inoculated"
the Membrane Filtration method and Most with sample water, they are incubated for up to
Probable Number method. four days and then examined.
The test tubes are observed for a positive or
Membrane Filtration (MF) negative reaction from the target organism. A
The Membrane Filtration (MF) method positive result would show bacteria growth and
the presence of gas within the tube. (e.g., When
involves filtering a measured amount of sample the sence of as within the tube When
water through a membrane filter that is designed
to retain the targeted bacteria. This is usually 14 Incubators rangefrom large expensive "stand-up"
models to something as simple as a box with a -watt
accomplished with an electric or hand vacuum models o some as a box h
I. See Suppliers List in the back of this circular for
pump that pulls sample water through the filter, more
leaving behind bacteria cells that are too large to
15 Four types of media that are used for the MPN method
pass through the pores. include: ". glutamate medium, lauryl
After the filtration process, the filter itself is tryptose broth, MacConkey broth, and lactose broth.
testing for fecal coliforms, a positive tube is one inverted and placed in an incubator. Once the
that shows evidence of growth and gas.) Tubes samples are incubated, bacteria colonies are
with positive growth are counted and the results counted and reported as "colony-forming units"
are used to estimate the "most probable number" per milliliter of water sample (CFUs/mL).
of bacteria in a water sample. This estimate is S d pe m i d f
Spread plate method- is different from the
achieved by using statistical probabilities-by
S.. pour plate method in that agar is poured onto the
comparing the number of positive tubes with a .
comparing the number of positive tubes with a plate and allowed to solidify before it is exposed
table of statistically determined numbers.16 As ,
to the sample. Once the agar is solidified, the
with anything statistical, the accuracy of this
sample is spread onto the plate surface with a
method is improved by increasing the number of
Sterilized bent glass rod and allowed to be absorbed
inoculated test tubes for each group of samples. into the agar medium before it is incubated.
into the agar medium before it is incubated.
Compared with the MF method, the MPN .
d w t M Colonies, that appear after a period of incubation,
test has several disadvantages, especially for
are identified and counted.
individuals wanting to do their own sampling
and bacteria testing: + Membrane Filtration technique see
Membrane Filtration on page 25.
(1) it's considerably more expensive and labor
intensive; Presence/Absence (P/A)
(2) because it involves the use of 10 to 15 test This method is just what its name implies.
tubes, this method also takes up quite a bit more Similar to the plate methods, it is mostly used for
incubator space; and monitoring drinking water. The theory holds that
(3) the MPN test does not yield a direct bacteria as long as there are zero coliform organisms within
count. a large number of samples, actual bacteria counts
are not necessary. In other words, testing is done
It does have one advantage, however; simply for the presence or absence of organisms.
suspended sediments within a water sample do While there may be problems with this
not affect the MPN process, whereas the MF approach as it relates to the use of recreational
method involves the use of filters that can waters, it can be an effective screening tool. For
become clogged with sediments and/or algae.17 example, if there are no total and/or fecal coliforms
This is something to consider if your water found in a sample, there is a high probability that
sample is from a lake or waterbody with high there is not a bacteria problem. Conversely, if
algal counts or turbidity problems (i.e., lots of total and/or fecal coliforms are present, one can
suspended solids). then go ahead and do more specialized testing
for identifying specific bacterial organisms or
groups such as fecal coliforms, Pseudomonas
Plate count methods are traditionally used aeruginosa, Enterococcus spp., etc.-whatever
for monitoring drinking water. The reference book one's budget will allow.
Standard Methods for the Examination of Water
and Wastewater8 describes three variations:
16 These tables are developed and used in bacteria
* Pour plate method -(a.k.a., the standard plate laboratories to calculate statistical probabilities.
method) involves pouring liquefied agar medium
Si i i i i 17 The Volunteer Monitor. Fall '98. Bacteria Testing
into petri dishes and then adding a measured Part I. Methods Primer. Page 9.
amount of sample water. Once the sample is
18 Often abbreviated as Standard Methods, this book is
mixed with the medium, the plates are left to sit considered to be the foremost authority on the science of
so the contents can solidify. They are then water analysis.
In the year 2000, Florida LAKEWATCH
began a preliminary statewide survey
collecting bacteria data on more than 80
lakes. The objectives of the survey are
two-fold. Using data from the survey,
1Trying to determine if there are patterns in
the abundance of total coliform bacteria and
the fecal coliform known as Escherichia coli
(E. coli) in Florida lakes and waterbodies. 7 .
Note: E. coli are a subgroup of fecal coliform
bacteria. Both fall under the larger category known
as total coliforms. See page 20for more information. What does this mean?
2 Looking for relationships that can be High total coliform counts, as found in 15% of the
drawn between coliform abundance and samples, are generally associated with abundant
other environmental factors such as changes in plant material, and may indicate the potential for
water temperature, rainfall, aquatic plant a variety of infections, including skin rashes
abundance, algae blooms, etc. and/or external ear infections in swimmers.
The presence of abundant plant material also
Florida LAKEWATCH uses the membrane introduces the possibility of other water-related
filtration technique for fast, simultaneous illnesses such as swimmer's itch.
detection of total coliforms and the fecal coliform
known as E. coli. Test kits are purchased from The low E. coli counts suggest that there is not a
the HACH Company and are identified as major problem with fecal contamination in this
Method 10029 m-ColiBlue24 Broth. sampling of Florida lakes (i.e., even though the
data are preliminary).
Most Florida LAKEWATCH bacteria samples
have been collected one time only from each of
the lakes involved in the survey and therefore r details related to bacteria detection
should only be considered as a description of techniques are sure to change in the
the bacteria concentrations for that day; data improvements continue to
coming years as improvements continue to
posted in the annual LAKEWATCH Data Sum-
be made, on an almost daily basis, in the micro-
mary book 1986-2001 are not intended for use
in making public safety decisions. However, biology field. For this reason, we are reluctant
in making public safety decisions. However,
to get too specific about the many techniques,
they are helpful in looking at patterns among
bacteria counts and other environmental factors. agars, broths, incubation temperatures, etc.
For a historical perspective we recommend
Preliminary analyses of the data shows that
that you refer to a copy of Standard Methods
15% of the (approximately) 1,000 samples
for the Examination of Water and Wastewater.
collected had total coliform counts that would for the Examination of Water and Wastewater.
exceed Florida's state criteria for total coliforms. For the latest up-to-date information, we
However, less than 0.01% of the samples had suggest you contact any of the laboratory
E. coli counts that would have exceeded suppliers listed in the back of this booklet.
Florida's state criteria for fecal coliforms.
ike many other states, Florida has established In August 2000, the Florida Department of
numerical bacteria counts that are used as Health initiated the Florida Healthy Beaches
the legal standard for determining the Program. The program was designed to assess
presence of total and/or fecal coliform contamina- the bacteriological quality of coastal beaches in
tion in Class III waters.19 The criteria are the 34 counties. To do this, the Department of Health
same for both fresh and marine waters: measures both fecal coliforms and enterococci.
Florida's total coliform standard The following criteria for fecal coliforms,
Less than or equal to 1,000 as a monthly aver- were established by the Florida DEP and are
age; nor to exceed 1,000 in more than 20% of the based on the legal criteria established by
samples examined during any month; less than Florida law:
2,400 at any time. Monthly averages shall be ex-
pressed as geometric means based on a minimum Fecal coliforms:
of 10 samples taken over a 30-day period using Good = 0-199 fecal coliforms per 100 milliliters (mL)
either the MPN or MF counts.20 of marine water
Florida's fecal coliform standard Moderate = 200-799 fecal coliforms per 100 mL
MPN or MF counts shall not exceed a monthly Poor = 800 or greater fecal coliforms per 100 mL
average of 200, nor exceed 400 in 10% of the
samples, nor exceed 800 on any one day. Monthly Note: If afecal "" count is observed to exceed 800
averages shall be expressed as geometric means colonies per 100 of beach water and a re-sampling
based on 10 samples taken over a 30-day period. result also exceeds this value, then a health warning
would be issued for the sampling site.
* Florida Department of Environmental Protection; The following criteria for enterococci bacteria
Chapter 62-302.530, Florida Administrative Code. have been recommended by the U.S. EPA as
Sa saltwater quality indicator. As of 2002, they
19 Class III waters are '. as "waters designated for have not been established as legal criteria.
the purpose of recreation and the propagation and Enterococci:
maintenance of healthy, well-balanced populations of fish
and Good = 0-34 enterococci per 100 milliliters (mL) of
20 The abbreviation MPN stands for Probable marine water
Number." The MPN technique refers to a .. "" method, Moderate = 35-103 enterococci per 100 mL
used in laboratories, to estimate the number of bacteria
colonies in a measured amount of wate, usually 100 ml Poor = 104 or greater enterococci per 100 mL
The abbreviation MF stands for li. ane Filter." The Note: If Enterococci results are observed to equal or
MF technique refers to a "' method used to count the exceed 104 colonies per 100 milliliters of beach water
number of bacteria colony forming units (or CFUs) on a sampled and a re-sampling result also exceeds this value,
membrane filter after 100 milliliters of sample water have an "Advisory" (not as strong as a "Warning") would be
been poured through it. issued for the sampling site.
With careful thought and good detective work,
it is possible to locate the sources) of bacterial contamination.
U unless there is a catastrophic failure of a there is evidence that bacterial contamination may
major sewage collection line, finding be present, it can help pinpoint possible sources.
the source of bacterial contamination in While there is no guarantee that these efforts will
a lake or waterbody can be difficult, time consum- find every source, there is a high probability that
ing and, depending on which testing regimen you most of the important ones can be identified.
choose, it can also be expensive. In fact, lack of Also, the LAKEWATCH approach is based
funding is often the largest hurdle that citizens largely on the use of total and fecal coliform
run into when sampling is proposed. counts. These methods are recom-
Because of this, public agencies Re-sam le! mended because they are generally
are often hard-pressed to conduct easier and less expensive to process
bacteria testing in a timely or than other tests currently available
consistent manner. If they have the Re-sample! and are therefore, more accessible
resources to sample at all, it's often to the average citizen or monitoring
limited to one sampling event, Re-sampie! group. In fact, more and more
which usually tells little. volunteer groups are investing in
Re-sample! basic laboratory equipment (i.e.,
The Good News incubator and test kits) and are
With careful thought and doing the testing themselves. Now,
some good detective work, it is possible to locate thanks to the development of several new cultur-
the sources) of bacterial contamination. Working ing mediums, E. coli counts are just as easy as to
together, lakeside communities can raise money process as total and fecal coliform counts.
to pay for sampling by private laboratories or
they can do it themselves. Regardless of which See page 27 for more on the E. coli count testing
method used by LAKEWATCH.
approach you take, Florida LAKEWATCH's Four
Step process-described on the following One more thing: the fecal coliform count
pages-provides a simple framework and relatively "criteria" in Steps 2 and 3 are roughly based on
inexpensive testing strategy to follow. It was Florida's state regulatory codes. This is not a
developed by LAKEWATCH staff in response coincidence. However, the importance of the
to hundreds of inquiries and a pilot study that following four step plan goes well beyond state
was conducted in several counties. regulatory codes, which are apt to change in the
When reading through the steps, you may near future. Our main goal in presenting this
notice that re-sampling often, and in many loca- information is to: (1) enable you to determine if
tions, is a major component of our plan. It's been there is a problem to begin with; (2) enable you
our experience that a willingness to do this will to spot patterns in your test results; and (3) help
help assess risks related to water usage and, if you locate the source of contamination.
Step 1 Step 2
Collect Water Samples from Multiple Sites Identify Sites with Elevated
Fecal Coliform Counts
If contamination is suspected, sampling at a
single site will not provide sufficient information Once fecal coliform counts have been
to make an accurate assessment of the problem. obtained from various sampling sites on your
Therefore, it's recommended that water samples lake, classify them using the three categories
be collected from approximately 12 sites, spaced listed below. Generally speaking, if the sample
as uniformly as possible around the lake or results fall within Low Risk category, the water-
waterbody. Nine of the sampling sites should be body would generally be considered "safe," as
located near shore. they are within Florida's criteria for Class III
It's also recommended that three sites be waters. However, if samples fall into the Poten-
sampled offshore in open water, as this will permit tial Risk or High Risk categories, they may not
a judgment of the magnitude of contamination. meet Florida's Class III water standards and re-
If the waterbody has a large amount of sampling is strongly recommended.
aquatic plants, try to sample just away from the Low Risk Category
plants. If there are not a lot of aquatic plants, the Sampling sites with fecal coliform counts of less
samples should be collected in water less than than 200 (CFUs per 100 mL)
three feet deep, as this offers the best possible As a general rule, sampling sites with fecal
chance of detecting contamination. coliform counts of 0 -199 colonies per 100 milli-
All samples should then be analyzed for fecal liters of water (CFUs per 100 mL) are most
coliform counts. This can be done in a professional likely not a problem and for all practical pur-
laboratory or even with the help of some home- poses, the bacteriological quality of these sites
monitoring kits that are now on the market. can be ranked as good. Furthermore, if all the
sites in the waterbody have results in this
See List of Suppliers in the back of this circular.
category, there is a strong possibility that the
waterbody is not being contaminated.
Note: It must always be recognized that even a count of
zero bacteria does not absolutely preclude the possibility
Potential Risk Category
Sampling sites with fecal coliform counts ranging
between 200 and 799 (CFUs per 100 mL)
Sampling sites with fecal coliform counts
ranging between 200 and 799 CFUs per 100 mL
of water represent sites with potential fecal
contamination. One of the first things to do when
such results are obtained, is to examine the
sampler's field notes and any comments from
local residents regarding possible reasons as to
why the counts would be high at the sites.
Move to Step 3.
While disposable Whirl-Pak baggies are popular
for the collection of bacteria water samples, plastic Note: There is really no need to re-sample areas that meet
Nalgene bottles can also be used. The only draw- Florida's fecal " criteria [see Chapter 62-302.530,
back is that they need to be sterilized each time. Florida Administrative Code]
High Risk Category
Sampling sites with fecal coliform counts,
of 800 or greater (CFUs per 100 mL)
When a fecal coliform result is observed
to exceed 800 CFU/100 mL of water sampled, :
consideration should be given to issuing a health
warning for the sampling site until re-sampling
can be done. State rules indicate that health
warnings should only be issued after additional
samples provide high counts. This is considered
the best approach to prevent undue public con- When testing for false positives, the primary
cern, but the public should at least be notified focus should begin with birds. Are birds residing
that additional testing is planned. Move to Step 3. in these areas on a regular basis or being routinely
fed at these sites? If the answer is yes to either of
Step 3 these questions, birds may be the most logical
Test for E. coli and Look for False Positives explanation rather than septic tanks or sewage
lines. If you want to be sure that birds are the culprit,
Once you have determined (from Step 2) you can test for two specific organisms that may
that fecal coliform counts are high, the objective be showing up in your fecal coliform testing
at this stage should be: regimen, Enterococcus avium and Enterococcus
gallinarium. To do this, you will need to contract
* To determine whether or not there are E. coli with a private laboratory.
organisms present in the fecal coliform tests; and i ie bird-ind d
If it is indeed a bird-induced problem,
* To rule out the possibility of "false positives" various management strategies can be tried.
that may have occurred due to large concentrations Steps can be taken to encourage the birds to
of birds (i.e., bird waste) and/or the presence of leave and/or discourage them from roosting in
the naturally occurring soil bacterium known as the area. Hunting (when legal) and noise devices
Klebsiella. can be effective, but you'll need to check with
your local wildlife agency before implementing
Test for E. coli It is recommended that you either of these approaches. The good news is,
have a private laboratory do the testing for E. coli. this usually means you have eliminated the need
If it is demonstrated that the vast majority of for further testing.
detected fecal coliforms belong to the E. coli If high fecal counts are not related to birds,
bacteria group, there is a high probability that the the next thing you should do is test specifically for
contamination source is human and continued re- the Klebsiella bacteria. The presence of these
sampling at the water body is warranted until the organisms in a fecal coliform test can also give
source of contamination is found and eliminated, false positives-especially in Florida. If tests
It is also recommended that you contact your indicate that high fecal coliform counts are due
local public health agency and move on to Step 4. to Klebsiella, then there is no serious health risk
and the need for further testing can most likely
Rule out false positives If E. coli are not be eliminated.21 If tests indicate that high fecal
detected, yet the fecal coliform counts remain counts are not related to Klebsiella, then it is
high, two possibilities should be considered: time to move to Step 4.
Contamination from birds (ducks, geese, sea 21 There is no evidence to that Klebsiella bacteria
gulls, etc.) or false positives from soil borne have caused any healthy individuals to experience
bacteria. illnesses due to exposure in the natural environment.
Step 1 Collect at least 12 water samples and
analyze them for fecal coliform counts. Go to Step 2
(9 nearshore, 3 offshore and open water)
Step 2 Identify sites with elevated fecal coliform counts.
If counts are 0-199 CFU/100 ml, then no further
testing is required
If counts are:
200-799 CFU/100 ml (Potential Risk) orea Go to Step 3
>800 CFU/100 mi (High Risk)
Step 3 oTest for E. coli;
SRule out false positives.
If the vast majority of detected fecal coliforms
belong to E. coi group, then high probability that o o o to e e
the search down to a smaller area.
Oc rn the contamination source is human. o te t e o
SSource needs to be found and eliminated.e
remain high, test for false positive readings
from organisms found in bird feces (Enterococcus
avium and Enterococcus gallinarium) or the
presence of Klebsiella bacteria.
If none of these organisms are present,
then no further testing is required.
Step 4 Re-sample sites with elevated fecal coliform counts
and narrow down the search area until the source
of contamination has been identified.
Step 4 Attention should be given to the locations of in-
Re-sample Sites with Elevated Fecal flowing streams, ditches, stormwater pipes, and/or
Coliform Counts water currents, with additional consideration
given to larger point sources such as farms.
Because false positives have been ruled out If fecal coliforms are higher in one area,
by now, the remainder of your bacteria testing you will have narrowed down your search area
can be done using the less expensive fecal coliform and greatly improved the chances of identifying
test. The objective of this sampling regimen is to the source.
identify the location of a contamination source.
See page 35 for Locations to Consider When
Sites that have been identified as potential Identifying and Locating Possible Sources of
sources should be re-sampled as soon as possible. Contamination.
With these results, it may be possible to narrow If the source for contamination is not
the search down to a smaller area.
readily found, the assistance of local property
Once re-sampling is initiated, new sites
owners should be enlisted in the effort. Specifi-
should be chosen near previously identified sites
cally, they should be asked to examine their
(i.e., those with high fecal coliform counts).
When tracking down suspected sources of bacterial
contamination, special consideration should be given
to the following locations:
* In-flowing pipes, ditches or streams If you know
of a place where water comes into a lake or waterbody, it's
a good idea to follow (i.e., on foot) the pipe or stream and
identify any other locations where water may be entering
the system. Make an effort to determine what water source
the pipe is linked to. It may be coming from a previously
+ Water currents For example, look at the way sub-
mersed aquatic vegetation (i.e., aquatic plants) may be
bending or leaning, as it could be an indication of the
direction that water is flowing into a lake. Follow that
source and collect water samples at evenly spaced intervals.
* Potential point sources Identify areas with high
densities of animals that might represent potential problems
(i.e., farms, ranches, pet parks, etc.). Keep in mind that even
if these areas are not visible from the shoreline or are located
away from the waterbody, stormwater runoff could still drain
from them. However, it must also be said that larger "point
sources" such as farms sometimes attract misdirected atten-
tion when it comes to suspected bacterial contamination.
Nothing should be assumed until the actual source is confirmed
with additional sampling. Quite often, the real culprit turns
out to be something other than the original suspected source,
such as a leaking sewer pipe between the farm and the lake.
+ Septic systems When a contamination source is not
readily found, the assistance of local property owners can be
enlisted to help find the source. Specifically, they should be
asked to examine their septic drainage field for possible
breach sites. If a sewage smell is detectable, it may be an
indication that additional sampling is needed in the area.m
septic drainage field for possible breach sites. is much less of a problem than it used to be. As
They should also be encouraged to use the "smell" they say, "the cup is at least half full." Rather
test. If they can smell a sewage odor, this alone than being fearful, citizens are encouraged to
is evidence for supporting additional sampling, remain vigilant and solve problems as they
Once the source of contamination is identified emerge.
and it is determined that the problem cannot be As far as the future is concerned, we all
easily remedied by the private homeowner or need to pay close attention to the developing
community, report it to your public health technology for measuring bacterial contamina-
agency. If the source happens to be on public tion. Things are changing almost daily and better
land, you may have to recruit assistance to raise techniques are becoming available. For the time
funds to solve the problem or to exert pressure being, however, the use of total coliform, fecal
on governmental agencies to fix it. coliform and E. coli counts continues to do the
job in most instances-especially when combined
Conclusion with the Four Step approach described in this
Franklin Delano Roosevelt once stated, circular.
"We have nothing to fear, but fear itself!" Life So for now, one can take comfort in know-
itself is not without risk, and aquatic activities ing that if total and fecal coliform counts are
are certainly not exempt. It is impossible to below the legal state-established criteria, there is
guarantee with 100% confidence that an indi- a strong probability that the water is safe for
vidual will not become ill upon contact with water. recreation. With that knowledge, we hope you'll
However, with the technology and information enjoy Florida's wealth of unique and refreshing
now available, bacterial contamination of water aquatic environments-in good health!
Phone: (800) 227-4224
Phone: (800) MILLIPORE
Phone: (800) 221-1975 or (800) 645-5476
Micrology Laboratories (for Coliscan products)
Phone: (888) 327-9435
IDEXX Laboratories (for Colilert products)
Phone: (207) 856-0300
American Public Health Association. 1998. STANDARD METHODS for the Examination of Water
and Wastewater. 20th Edition. American Public Health Association. Waldorf, Maryland.
Canadian Council of Ministers of the Environment. 1999. Canadian Water Quality Guidelines.
Eco-Health Branch. Ecosystem Sciences and Evaluation Directorate. Environment Canada.
Hach Company. 2000. Hach's Technical Information Series-Booklet No. 13, The Use of Indicator
Organisms to Assess Public Water Safety (Literature #7015.)
Hach Company. 2000. Microbiological Laboratory Start-up Guide. See Microbiological Testing
Section, pages 135-182.
Hach Company. 2000. Analytical Procedures. Coliforms: Membrane Filtration (simultaneous
detection) for the detection of total coliforms and E. coli from potable water, non-potable
Hach Company. 1997. Products for Analysis Catalog (Literature #3226).
The Volunteer Monitor. 1998. Issue Topic: Monitoring Estuaries. Special Section: Bacteria Testing,
Part 1. Volume 10, No. 2. Fall. Pages 8-15.
Note: T publication is a must for individuals or groups interested in doing their own bacteria testing.
Numerous testing methods are discussed and compared and is even provided on how
to build an incubator.
Toranzos, G. A. 1991. Current and possible alternate indicators of fecal contamination in tropical
waters: a short review. Environmental Toxicology and Water Quality 6: 121-130.
U.S. EPA. 2000. Non-point Source News-Notes. Special Focus: On-site Wastewater Treatment.
December. Number 63.
Note: News-Notes are accessible on EPA's website: www.epa.gov/OWOW/info/NewsNotes/index.html