Download Fecal Coliform

Name ___________________________________
Date ________________
As you close read the background information on chemical and biological water quality indicators, answer each of
the following questions.
Fecal coliform and E. coli Bacteria
http://education-portal.com/academy/lesson/monitoring-public-water-supplies-ecoli-threats.html#lesson
(watch first 2 minutes)
1. Why does the presence of E. coli sometimes lead to beach closings?
2. What is the Vermont state standard for E. coli in swimming water?
pH
https://www.youtube.com/watch?v=h2tNAGlPebY#t=17 (
3. What is the pH range that will generally support life in an aquatic ecosystem?
4. List two human activities that could alter the pH of a water body.
Temperature
5. How does water temperature affect aquatic life?
6. List two human activities that could alter the temperature of a water body.
Turbidity
https://www.youtube.com/watch?v=5jJWMmIYMlw (watch first 2 minutes)
7. What does turbidity measure?
8. Why do turbid waters support less aquatic life?
Benthic Macroinvertebrates
9. What is a benthic macroinvertebrate?
10. List two reasons benthic macroinvertebrates are useful indicators of water quality.
Dissolved Oxygen (DO)
https://www.youtube.com/watch?v=9Jk0AmmuLSY (watch1:30 seconds, this is not the method we will use)
11. What is dissolved oxygen? Why is it important to aquatic life?
12. List 1 physical and 1 biological factor that might increase DO levels.
13. List 1 physical and 1 biological factor that might decrease DO levels.
Phosphorus
14. What is phosphorus? Why is it essential for aquatic life?
15. What are the different forms of phosphate (a phosphate ion) and where are they found?
16. Why can human caused enrichment of phosphorus be a problem? (cultural eutrophication)
Physical Survey
17. What ‘three zones’ are covered in a physical survey of the stream?
18. What is meant by embeddedness?
19. How is the condition of the banks related to the health of the stream? Give an example.
Fecal coliform bacteria are found in the feces of human beings and other warm-blooded animals. Fecal
coliform by themselves are generally not pathogenic (a biological agent, such as a bacterium or virus, that can
cause a disease). Pathogenic organisms include bacteria, viruses and parasites that cause diseases and illnesses.
Fecal coliform bacteria are already inside of you! They occur naturally in the human digestive tract and aid in the
digestion of food. However, when a human being or other warm-blooded animal is infected with disease,
pathogenic organisms are found along with fecal coliform bacteria.
If fecal coliform counts are high (over 200 colonies/100 ml of a water sample) in a river or lake, there is a greater
chance that pathogenic organisms are also present. If you are swimming in waters with high levels of fecal
coliform, you have a greater chance of developing a fever, nausea or stomach cramps from swallowing diseasecausing organisms, or from pathogens entering the body through cuts in the skin, the nose, mouth, or ears. Some
examples of diseases and illnesses that can be contracted in water with high fecal coliform counts include typhoid
fever, hepatitis, gastroenteritis, dysentery and ear infections.
Why not test pathogens? Pathogens are relatively scarce in water, making it time-consuming and expensive to
monitor them directly. Instead, we monitor fecal coliform because of the possible correlation between fecal
coliform and the probability of contracting a disease from the water.
Fecal Coliform Standards
Drinking Water = 0 FC/100 mL
Partial body contact = 1000 FC/100 mL
Swimming = 200 FC/100 mL
Treated sewage effluent = less than 200 FC/100 ml
Fecal coliform bacteria are living organisms, unlike the other conventional water quality parameters. The fecal
coliform bacteria multiply rapidly when conditions are good for growth and die in large quantities when they are
not.
E. coli (Escherichia coli) is a species of fecal coliform bacteria that is specific to fecal material from humans and
other warm-blooded animals. There are three different categories of water quality standards for bacteria based on
water use: total body contact (swimming), partial body contact (boating), and drinking water. In Vermont, the state
standard for swimming is 77 colonies/100ml. At this level, there is a risk that 6 out of 1000 swimmers will get sick.
For boating, the state standard is 200 colonies/100ml, and for drinking water the Vermont standard is 0
colonies/100ml. *
Sources of fecal contamination of surface waters include wastewater treatment plants, onsite septic systems,
domestic and wild animal manure, and urban runoff. Fecal matter can enter the river system directly from pipes
and from excretion of animals, or are carried by surface runoff after rain.*
*Excerpt from:
Behar, Sharon. Testing the Waters: Chemical and Physical Vital Signs of a River. Kendall/Hunt: Iowa, 1996. p.
165.
*Chart from EPA
pH is the percentage of hydrogen ions (H+) in a solution. A solution is more acidic when it contains more
hydrogen ions. The level of acidity of the water is important to the plant and animal life there. Most animals are
adapted to living in neutral conditions. Changes in pH endanger the lives the organisms in the water.
The level of acidity can be changed by human’s actions. Acid rain, a result of air pollution and matter emitted from
tailpipes and smokestacks affect the pH. When these things combine with water in the atmosphere, they form
sulfuric and nitric acids, then fall to the earth as acid rain, snow, hail, and fog. This precipitation mixes with water
already on the earth, in creeks, rivers, ponds and wetlands. Other pollutants carried by runoff from the land, also
change the acidity of the water.
A pH of 7 is considered to be neutral. When the pH is less than 7, it is acidic; a pH greater than 7 is basic. A pH
value between 7.0 and 8.0 are optimal for supporting a diverse aquatic ecosystem. A pH range between 6.5 and 8.5
is generally suitable.
Temperature
The rates of biological and chemical processes depend on temperature.
Temperature affects the oxygen content of water (oxygen levels become lower as temperature increases); the rate of
photosynthesis by aquatic plants; the metabolic rates of aquatic organisms; and the sensitivity of organisms to toxic
wastes, parasites, and diseases.
Causes of temperature change include weather, removal of shading stream bank vegetation, impoundments (a body
of water confined by a barrier, such as a dam), discharge of cooling water, urban storm water, and groundwater
inflows to the stream.
Thermal pollution is a way that the temperature of water can increase. Thermal pollution is an increase in water
temperature caused by adding relatively warm water to a body of water. Thermal pollution can come from
stormwater running off warmed urban surfaces (streets, sidewalks, parking lots) and industries that discharge warm
water from their facilities that was used to cool machinery.
Turbidity is a measure of the relative clarity of water: the greater the turbidity, the murkier the water. Turbidity
increases as a result of suspended solids in the water that reduce the transmission of light. Suspended solids are
varied, ranging from clay, silt and plankton, to industrial wastes and sewage.
So the water is dirty, what's the big deal?
With higher levels of turbidity, water loses its ability to support a diversity of aquatic organisms.
Water becomes warmer as suspended particles absorb heat from the sunlight and cause oxygen levels to fall.
Remember- warm water holds less oxygen than cooler water!
Photosynthesis decreases because less light penetrates the water, resulting in even further drops in oxygen levels.
The combination of warmer water, less light and oxygen depletion makes it impossible for some forms of aquatic
life to survive.
Suspended solids affect aquatic life in other ways as well. Suspended solids can clog fish gills, reduce growth rates,
decrease resistance to disease and prevent egg and larval development. Particles of silt, clay and organic materials
settle to the bottom, especially in areas of a river or stream that are slow moving. These settled particles could
smother the eggs of fish and aquatic insects, as well as suffocate newly hatched insect larvae. Material that settles
into the spaces between rocks makes these microhabitats unsuitable for mayfly and stonefly nymphs, caddisfly
larvae and other aquatic insects living there.
Why Study the Stream-Bottom Macroinvertebrates?
* Stream-bottom macroinvertebrates are an important part of the community of life found in and around a stream.
Stream-bottom macroinvertebrates are a link in the aquatic food chain. In most streams, the energy stored by plants
is available to animal life either in the form of leaves that fall in the water or in the form of algae that grows on the
stream bottom. The algae and leaves are eaten by macroinvertebrates. The macroinvertebrates are a source of
energy for larger animals such as fish, which in turn, are a source of energy for birds, raccoons, watersnakes, and
even fishermen.
* Stream-bottom macroinvertebrates differ in their sensitivity to water pollution.
Some stream-bottom macroinvertebrates cannot survive in polluted water. Others can survive or even thrive in
polluted water. In a healthy stream, the stream-bottom community will include a variety of pollution-sensitive
macroinvertebrates. In an unhealthy stream, there may be only a few types of nonsensitve macroinvertebrates
present.
* Stream-bottom macroinvertebrates provide information about the quality of a stream over long periods of time.
It may be difficult to identify stream pollution with water analysis, which can only provide information for the time
of sampling. Even the presence of fish may not provide information about a pollution problem because fish can
move away to avoid polluted water and then return when conditions improve. However, most stream-bottom
macroinvertebrates cannot move to avoid pollution. A macroinvertebrate sample may thus provide information
about pollution that is not present at the time of sample collection.
* Stream-bottom macroinvertebrates are relatively easy to collect.
Useful stream-bottom macroinvertebrate data are easy to collect without expensive equipment. The data obtained
by macroinvertebrate sampling can serve to indicate the need for additional data collection, possibly including
water analysis and fish sampling.
From: http://wsrv.clas.virginia.edu/~sos-iwla/Stream-Study/StreamStudyHomePage/WhyStudyMacro.HTML
accessed 10.01.06