D2 WATER DISTRIBUTION TEST QUESTIONS
WITH CORRECT ANSWERS 2025/2026
What is the primary purpose of the SWDA? - CORRECT ANSWER -To create uniform national
standards for drinking water quality
Who sets Maximum Contaminants Levels (MCLs)? - CORRECT ANSWER -USEPA
What are some of the duties of the EPA? - CORRECT ANSWER -Sets MCLs, delegates
enforcement of SDWA to state agencies, provides grant funds, monitors state activities, provides
continued research
What is state primacy? - CORRECT ANSWER -Giving the authority to the state to implement and
enforce regulations
True or False: State requirements must be at least as stringent as those set by USEPA - CORRECT
ANSWER -True.
A public water system is a system that supplies piped water for human consumption and that
has at least ___ service connections or serves ___ or more persons for ___ or more days of the
year. - CORRECT ANSWER -15, 25, 60
What is an nontransient, noncommunity public water system? Give an example of one. -
CORRECT ANSWER -Establishments with their own private water systems that serve an average
of 25 persons that do not live at the location, but the same people use the water for more than
6 months per year. Example: school or factory
What is a transient, noncommunity public water system? Give an example of one. - CORRECT
ANSWER -Establishments with own water system and serve at least 25 persons a day but these
people only use the water occasionally and for short periods of time. Example: Motel or Park
,What is a community public water system? Give an example of one. - CORRECT ANSWER -
Establishments with their own water supply that serve more than 15 homes. Example: HOA, or
municipal water utilities
Which of the public water systems are required to only monitor for nitrate, nitrite, and
microbiological contamination? - CORRECT ANSWER -transient, noncommunity
What does the National Primary Drinking Water Regulations (NPDWRs) specify? - CORRECT
ANSWER -MCLs or a treatment technique requirement for contaminants that may be found in
drinking water and could have an adverse health effect on humans
What does the National Secondary Drinking Water Regulations (NPDWRs) specify? - CORRECT
ANSWER -water contaminants that may adversely affect aesthetic qualities of the water such as
taste, odor or color
When must an agency post a public notification? - CORRECT ANSWER -When the water system
violates any of the operating, monitoring or reporting requirements or if they exceed the MCL
Lead and Copper Rule (LCR) - CORRECT ANSWER -Requires that samples be collected at
customers taps after the water has remained undisturbed in the water piping for at least 6 hrs
True or False: system operators are required to regularly collect and test water samples. -
CORRECT ANSWER -true
True or False: Water quality cannot change after it enter the distribution system. - CORRECT
ANSWER -false -blending, season, operational changes
What are the 4 methods of collecting samples? - CORRECT ANSWER -Grab sample, composite
sample, time composite sample, flow-proportional composite sample
, What is a grab sample? - CORRECT ANSWER -A single sample at a single location
What is a composite sample? - CORRECT ANSWER -A series of grab samples at one place and at
different times
What is a time composite sample? - CORRECT ANSWER -Equal volumes at regular intervals
What is a flow proportional composite sample? - CORRECT ANSWER -Adjusting the sample size
proportional to the flow
How do you select a sample point? - CORRECT ANSWER -As close to the main as possible
True or false: It is required for samples to be taken from groundwater under the direct influence
of surface water. - CORRECT ANSWER -true
What are Sanitary Surveys? - CORRECT ANSWER -On site annual inspection of a water system's
facilities and operation.
What are some the requirements that the State establishes to ensure proper water system
operation? - CORRECT ANSWER -Operator Certification, sanitary surveys, enforcement
What are the 3 main areas of concern to distribution operators? - CORRECT ANSWER -
microbiological safety, disinfection by products, lead
Total coliform rule - CORRECT ANSWER -to require surveillance of total coliform bacteria
WITH CORRECT ANSWERS 2025/2026
What is the primary purpose of the SWDA? - CORRECT ANSWER -To create uniform national
standards for drinking water quality
Who sets Maximum Contaminants Levels (MCLs)? - CORRECT ANSWER -USEPA
What are some of the duties of the EPA? - CORRECT ANSWER -Sets MCLs, delegates
enforcement of SDWA to state agencies, provides grant funds, monitors state activities, provides
continued research
What is state primacy? - CORRECT ANSWER -Giving the authority to the state to implement and
enforce regulations
True or False: State requirements must be at least as stringent as those set by USEPA - CORRECT
ANSWER -True.
A public water system is a system that supplies piped water for human consumption and that
has at least ___ service connections or serves ___ or more persons for ___ or more days of the
year. - CORRECT ANSWER -15, 25, 60
What is an nontransient, noncommunity public water system? Give an example of one. -
CORRECT ANSWER -Establishments with their own private water systems that serve an average
of 25 persons that do not live at the location, but the same people use the water for more than
6 months per year. Example: school or factory
What is a transient, noncommunity public water system? Give an example of one. - CORRECT
ANSWER -Establishments with own water system and serve at least 25 persons a day but these
people only use the water occasionally and for short periods of time. Example: Motel or Park
,What is a community public water system? Give an example of one. - CORRECT ANSWER -
Establishments with their own water supply that serve more than 15 homes. Example: HOA, or
municipal water utilities
Which of the public water systems are required to only monitor for nitrate, nitrite, and
microbiological contamination? - CORRECT ANSWER -transient, noncommunity
What does the National Primary Drinking Water Regulations (NPDWRs) specify? - CORRECT
ANSWER -MCLs or a treatment technique requirement for contaminants that may be found in
drinking water and could have an adverse health effect on humans
What does the National Secondary Drinking Water Regulations (NPDWRs) specify? - CORRECT
ANSWER -water contaminants that may adversely affect aesthetic qualities of the water such as
taste, odor or color
When must an agency post a public notification? - CORRECT ANSWER -When the water system
violates any of the operating, monitoring or reporting requirements or if they exceed the MCL
Lead and Copper Rule (LCR) - CORRECT ANSWER -Requires that samples be collected at
customers taps after the water has remained undisturbed in the water piping for at least 6 hrs
True or False: system operators are required to regularly collect and test water samples. -
CORRECT ANSWER -true
True or False: Water quality cannot change after it enter the distribution system. - CORRECT
ANSWER -false -blending, season, operational changes
What are the 4 methods of collecting samples? - CORRECT ANSWER -Grab sample, composite
sample, time composite sample, flow-proportional composite sample
, What is a grab sample? - CORRECT ANSWER -A single sample at a single location
What is a composite sample? - CORRECT ANSWER -A series of grab samples at one place and at
different times
What is a time composite sample? - CORRECT ANSWER -Equal volumes at regular intervals
What is a flow proportional composite sample? - CORRECT ANSWER -Adjusting the sample size
proportional to the flow
How do you select a sample point? - CORRECT ANSWER -As close to the main as possible
True or false: It is required for samples to be taken from groundwater under the direct influence
of surface water. - CORRECT ANSWER -true
What are Sanitary Surveys? - CORRECT ANSWER -On site annual inspection of a water system's
facilities and operation.
What are some the requirements that the State establishes to ensure proper water system
operation? - CORRECT ANSWER -Operator Certification, sanitary surveys, enforcement
What are the 3 main areas of concern to distribution operators? - CORRECT ANSWER -
microbiological safety, disinfection by products, lead
Total coliform rule - CORRECT ANSWER -to require surveillance of total coliform bacteria
