E004 Tulane EPHOC - Potable Water
Quiz Question and answers correctly
solved 2026
For which of the following microorganisms is chlorine a good disinfectant?
a. crytpo, viruses, bacteria
b. bacteria, viruses
c. bacteria, crypto
d. viruses, crypto - correct answer ✔b. bacteria, viruses
Which of the following is true about ground waters?
a. They are often safe to use without disinfection.
b. They are sometimes contaminated by natural contaminants like arsenic and can be contaminated by
septic tank and surface contaminants,
c. They are usually microbiologically safe if not Ground Water Under the Direct Influence of Surface
Water (GWUDI).
d. all of the above - correct answer ✔a. They are often safe to use without disinfection.
b. They are sometimes contaminated by natural contaminants like arsenic and can be contaminated by
septic tank and surface contaminants,
c. They are usually microbiologically safe if not Ground Water Under the Direct Influence of Surface
Water (GWUDI).
Why should all water supplies have periodic sanitary surveys?
a. Sanitary surveys can identify potential problems and help prevent quality and compliance problems.
b. Sanitary surveys are a good way to become familiar with water suppliers and operators and to assist
them.
c. Sanitary surveys are a teaching tool that helps water suppliers understand their system and do a
better job.
, d. all of the above - correct answer ✔a. Sanitary surveys can identify potential problems and help
prevent quality and compliance problems.
b. Sanitary surveys are a good way to become familiar with water suppliers and operators and to assist
them.
c. Sanitary surveys are a teaching tool that helps water suppliers understand their system and do a
better job.
Which of the following is true about excess nitrates and/or nitrites in drinking water?
a. Nitrates and nitrites are often caused by sewage or fertilizer contamination.
b. Nitrates and nitrites are water soluble and will move through soils to contaminate groundwater.
c. Infants 3 to 6 months old are at risk to methemoglobinemia from high nitrate or nitrite levels,
especially if the water is also microbially contaminated.
d. all of the above - correct answer ✔a. Nitrates and nitrites are often caused by sewage or fertilizer
contamination.
b. Nitrates and nitrites are water soluble and will move through soils to contaminate groundwater.
c. Infants 3 to 6 months old are at risk to methemoglobinemia from high nitrate or nitrite levels,
especially if the water is also microbially contaminated.
Which statement is correct regarding Drinking Water supplies?
a. they always have the potential risk of microbial contamination that must be managed and prevented
b. they are a significant contributor to cancer risks in the population due to disinfection by-products
c. they should be retreated in the home with Point of Use or Pint of Entry systems
d. they should be disinfected to become sterile so that no bacteria are present in the water - correct
answer ✔a. They always have the potential risk of microbial contamination that must be managed and
prevented.
What is the most appropriate use of chloramines in water treatment?
a. primary disinfectant
b. secondary disinfectants and depressants of disinfectant by-product formation
Quiz Question and answers correctly
solved 2026
For which of the following microorganisms is chlorine a good disinfectant?
a. crytpo, viruses, bacteria
b. bacteria, viruses
c. bacteria, crypto
d. viruses, crypto - correct answer ✔b. bacteria, viruses
Which of the following is true about ground waters?
a. They are often safe to use without disinfection.
b. They are sometimes contaminated by natural contaminants like arsenic and can be contaminated by
septic tank and surface contaminants,
c. They are usually microbiologically safe if not Ground Water Under the Direct Influence of Surface
Water (GWUDI).
d. all of the above - correct answer ✔a. They are often safe to use without disinfection.
b. They are sometimes contaminated by natural contaminants like arsenic and can be contaminated by
septic tank and surface contaminants,
c. They are usually microbiologically safe if not Ground Water Under the Direct Influence of Surface
Water (GWUDI).
Why should all water supplies have periodic sanitary surveys?
a. Sanitary surveys can identify potential problems and help prevent quality and compliance problems.
b. Sanitary surveys are a good way to become familiar with water suppliers and operators and to assist
them.
c. Sanitary surveys are a teaching tool that helps water suppliers understand their system and do a
better job.
, d. all of the above - correct answer ✔a. Sanitary surveys can identify potential problems and help
prevent quality and compliance problems.
b. Sanitary surveys are a good way to become familiar with water suppliers and operators and to assist
them.
c. Sanitary surveys are a teaching tool that helps water suppliers understand their system and do a
better job.
Which of the following is true about excess nitrates and/or nitrites in drinking water?
a. Nitrates and nitrites are often caused by sewage or fertilizer contamination.
b. Nitrates and nitrites are water soluble and will move through soils to contaminate groundwater.
c. Infants 3 to 6 months old are at risk to methemoglobinemia from high nitrate or nitrite levels,
especially if the water is also microbially contaminated.
d. all of the above - correct answer ✔a. Nitrates and nitrites are often caused by sewage or fertilizer
contamination.
b. Nitrates and nitrites are water soluble and will move through soils to contaminate groundwater.
c. Infants 3 to 6 months old are at risk to methemoglobinemia from high nitrate or nitrite levels,
especially if the water is also microbially contaminated.
Which statement is correct regarding Drinking Water supplies?
a. they always have the potential risk of microbial contamination that must be managed and prevented
b. they are a significant contributor to cancer risks in the population due to disinfection by-products
c. they should be retreated in the home with Point of Use or Pint of Entry systems
d. they should be disinfected to become sterile so that no bacteria are present in the water - correct
answer ✔a. They always have the potential risk of microbial contamination that must be managed and
prevented.
What is the most appropriate use of chloramines in water treatment?
a. primary disinfectant
b. secondary disinfectants and depressants of disinfectant by-product formation
