Chapter 2, the hazards of backflow Flashcards
These are low hazards, that are also agents that do not cause disease, but they do decrease the aesthetic quality of water.
Biological pollutants
Lactobacillus is a type of bacteria used in the production of yogurt. What is it classified as in relation to backflow?
A biological pollutant
These are agents that cause disease. Examples include bacteria, viruses, protozoa, algae, etc..
Biological contaminants
This biological contaminant is the bacteria that causes legionnaires disease
Legionella
Legionella is commonly found in what locations
Cooling towers, evaporators, condensers, and hot water tanks.
Modern treatment processes can effectively kill or remove most of the organisms. However, when contaminants backflow into the distribution system, treatment becomes somewhat irrelevant since the treatment system process has been:
Bypassed
These are created when ammonia is used in combination with chlorine
Chloramines
Which is more effective at killing biological contaminants, chlorine or chloramines?
Chlorine
Water Quality Monitoring frequencies are determined based on what?
Size of population
What is the minimum requirement for residual chlorine in a public water supply?
0.2 PPM
What is the minimum combined chlorine residual where chloramines are used?
0.6ppm
What is generally considered a better test for determining if the portable water system has been contaminated?
Testing the water for total coliforms
This is the amount of time that has passed between the ingestion of or contact with the biological agent and the first disease symptoms
Onset time
______ is the ability of an organism to make an individual ill.
Pathogenicity
______ is how ill the organism will make the individual
Virulence
________ is the term used when backflow preventers are installed at each possible point of contamination.
Isolation
______ is the term used when backflow prevention assemblies are used to keep contaminants from entering the distribution system from a water consumers facility
Containment, or service protection
Chemical pollutants are substances that do not pose a public health threat, but reduce the:
Aesthetic water quality
Chemical contaminants are substances that pose a threat to:
Public health
_____ refers to the poisonous nature of a chemical and varies widely
Toxicity
Often funding for backflow prevention programs is insufficient because of the costs of the program are more apparent than the
Benefits
