AWWA ABC Water Distribution Grades 1
& 2 Exam 2026 Questions and Answers
Which agency sets legal limits on the concentration levels of harmful contaminants
in potable water distributed to customers? - Correct answer-US Environmental
Protection Agency
The number of monthly distributions system bacteriologiacal samples required is -
Correct answer-Based on the population served
What is the maximum contaminant level for total trihalomethanes (TTHM) in the
united States? - Correct answer-0.080 mg/L
Under the Surface Water Treatment Rule, disinfection residuals must be collected
at the same location in the distribution system as - Correct answer-coliform
samples
Iron can cause "red water" and thus customer complaints when its concentration is
above its secondary maximum contaminant level of - Correct answer-0.30 mg/L
©COPYRIGHT 2025, ALL RIGHTS RESERVE 1
,The goal of the Surface Drinking Water Act is for each ________ to accept primary
enforcement responsibility (primacy) for the operation of the state's drinking water
program. - Correct answer-State
What is the objective of Total Coliform Rule? - Correct answer-To promote routine
surveillance of distribution system water quality to search for fecal matter and/or
disease-causing bacteria
Which agency sets standards on the concentration levels of harmful contaminants
in drinking water? - Correct answer-EPA
Explain the difference between the different tiers of violations. Which tier is the
most serious? - Correct answer-Tier 1 = 24 hours (most severe)
Tier 2= 30 days
Tier 3= 1 year
A positive E. Coli test must be reported to the primacy health agency within what
time period? - Correct answer-24 hours
How is the required number of monthly bacteriological samples determined? -
Correct answer-Population served
What is the action level for lead in first-draw samples taken from customer taps? -
Correct answer-0.015 mg/L
©COPYRIGHT 2025, ALL RIGHTS RESERVE 2
, A water system is designated a community public water system if it serves how
many homes? - Correct answer-15 or more
What authority provides specific water sampling instructions? - Correct answer-
The state primacy agency
According to the Lead and Copper Rule, what is the action level for lead? - Correct
answer-0.015 mg/L
Head is measured in - Correct answer-Feet
A plat is - Correct answer-a map
At which time of the day is the age of the water stored in the distribution system
the highest? - Correct answer-Early morning
Water mains should primarily be sized based on - Correct answer-adequate fire
flow at an appropriate pressure
The most desirable residential pressure ranges from - Correct answer-50 to 75 psi
(345 to 517kPa)
Domestic water use includes water that is supplied to residential areas,
____________, and institutional facilities. - Correct answer-commercial districts
Riparian doctrine is sometimes called the "rule of - Correct answer-reasonable
sharing."
©COPYRIGHT 2025, ALL RIGHTS RESERVE 3
& 2 Exam 2026 Questions and Answers
Which agency sets legal limits on the concentration levels of harmful contaminants
in potable water distributed to customers? - Correct answer-US Environmental
Protection Agency
The number of monthly distributions system bacteriologiacal samples required is -
Correct answer-Based on the population served
What is the maximum contaminant level for total trihalomethanes (TTHM) in the
united States? - Correct answer-0.080 mg/L
Under the Surface Water Treatment Rule, disinfection residuals must be collected
at the same location in the distribution system as - Correct answer-coliform
samples
Iron can cause "red water" and thus customer complaints when its concentration is
above its secondary maximum contaminant level of - Correct answer-0.30 mg/L
©COPYRIGHT 2025, ALL RIGHTS RESERVE 1
,The goal of the Surface Drinking Water Act is for each ________ to accept primary
enforcement responsibility (primacy) for the operation of the state's drinking water
program. - Correct answer-State
What is the objective of Total Coliform Rule? - Correct answer-To promote routine
surveillance of distribution system water quality to search for fecal matter and/or
disease-causing bacteria
Which agency sets standards on the concentration levels of harmful contaminants
in drinking water? - Correct answer-EPA
Explain the difference between the different tiers of violations. Which tier is the
most serious? - Correct answer-Tier 1 = 24 hours (most severe)
Tier 2= 30 days
Tier 3= 1 year
A positive E. Coli test must be reported to the primacy health agency within what
time period? - Correct answer-24 hours
How is the required number of monthly bacteriological samples determined? -
Correct answer-Population served
What is the action level for lead in first-draw samples taken from customer taps? -
Correct answer-0.015 mg/L
©COPYRIGHT 2025, ALL RIGHTS RESERVE 2
, A water system is designated a community public water system if it serves how
many homes? - Correct answer-15 or more
What authority provides specific water sampling instructions? - Correct answer-
The state primacy agency
According to the Lead and Copper Rule, what is the action level for lead? - Correct
answer-0.015 mg/L
Head is measured in - Correct answer-Feet
A plat is - Correct answer-a map
At which time of the day is the age of the water stored in the distribution system
the highest? - Correct answer-Early morning
Water mains should primarily be sized based on - Correct answer-adequate fire
flow at an appropriate pressure
The most desirable residential pressure ranges from - Correct answer-50 to 75 psi
(345 to 517kPa)
Domestic water use includes water that is supplied to residential areas,
____________, and institutional facilities. - Correct answer-commercial districts
Riparian doctrine is sometimes called the "rule of - Correct answer-reasonable
sharing."
©COPYRIGHT 2025, ALL RIGHTS RESERVE 3
