LEVEL 1 WATER DISTRIBUTION EXAM
STUDY GUIDE 2026 COMPLETE QUESTIONS
AND 100% CORRECT ANSWERS
⩥ Wells That Are Biologically Contaminated Must Be Bacteriologically
Surveyed and Samples Taken How Far Apart? Answer: At Least 12
Hours Apart
⩥ When Backfilling a Pipeline, How Deep Should the First Layer of
Backfill Be Compacted? Answer: At the Horizontal Centerline of the
Pipe
⩥ What Is an Important Step in Problem Solving? Answer: Realization
That a Problem Still Exists
⩥ What Type of Pipe Joint Is Considered Inflexible and Not Usually
Installed Below Ground? Answer: Flanged Joint
⩥ When Are Butterfly Valves Used in Distribution Systems? Answer:
Generally When the Pipeline Is Greater Than 16'' or When Throttling
Might Be Required or When a Motorized Operator Is Needed for
Automated Control
,⩥ Fire Hydrants Should Be Placed at What Intervals? Answer: 350 to
600 Feet Apart, At All Intersections, In Close Proximity When Used in
High-Value Commercial Applications
⩥ AWWA M-17 Fire Hydrants Requirement Answer: Two fire hydrants
are required for conducting a fire flow test as per AWWA M-17.
⩥ Unsafe Condition as per OSHA Answer: Working in granular soil with
a trench width less than 1:1 is considered an unsafe condition according
to OSHA regulations.
⩥ Type of Pump with Fixed Impeller Answer: A centrifugal pump
consists of an impeller fixed on a rotating shaft enclosed in a casing.
⩥ Purpose of a Check Valve Answer: A check valve is used to prevent
flow in a reverse direction.
⩥ Framework to Support Trench Walls Answer: Shoring is a complete
framework of wood and/or metal designated to support the walls of a
trench.
⩥ Issue with Improperly Adjusted Weighted Check Valve Answer:
Improperly adjusted weighted check valve can result in water hammer.
, ⩥ Protected Classes of Employees Answer: Protected classes of
employees include individuals over 40 years of age, gender, and political
affiliation.
⩥ Advantage of Gate Valves in Water Distribution Systems Answer:
Gate valves are used in water distribution systems due to their lower
friction compared to other valves.
⩥ Definition of Controlling Answer: Controlling involves ensuring
progress towards objectives and taking corrective actions as necessary.
⩥ Types of Maintenance in Preventative Maintenance Program Answer:
The four types of maintenance in a preventative maintenance program
are predictive maintenance, planned maintenance, and corrective
maintenance.
⩥ About how many gallons would a 6-inch pipeline, 1000 feet long
hold? Answer: Approximately 1500 gallons
⩥ Why is the objective of any safety program important? Answer: To
prevent accidents and ensure workplace safety
⩥ What is the chlorine residual in treated water with a dose of 2.1 mg/L
and a demand of 0.8 mg/L? Answer: Chlorine residual: 1.3 mg/L
STUDY GUIDE 2026 COMPLETE QUESTIONS
AND 100% CORRECT ANSWERS
⩥ Wells That Are Biologically Contaminated Must Be Bacteriologically
Surveyed and Samples Taken How Far Apart? Answer: At Least 12
Hours Apart
⩥ When Backfilling a Pipeline, How Deep Should the First Layer of
Backfill Be Compacted? Answer: At the Horizontal Centerline of the
Pipe
⩥ What Is an Important Step in Problem Solving? Answer: Realization
That a Problem Still Exists
⩥ What Type of Pipe Joint Is Considered Inflexible and Not Usually
Installed Below Ground? Answer: Flanged Joint
⩥ When Are Butterfly Valves Used in Distribution Systems? Answer:
Generally When the Pipeline Is Greater Than 16'' or When Throttling
Might Be Required or When a Motorized Operator Is Needed for
Automated Control
,⩥ Fire Hydrants Should Be Placed at What Intervals? Answer: 350 to
600 Feet Apart, At All Intersections, In Close Proximity When Used in
High-Value Commercial Applications
⩥ AWWA M-17 Fire Hydrants Requirement Answer: Two fire hydrants
are required for conducting a fire flow test as per AWWA M-17.
⩥ Unsafe Condition as per OSHA Answer: Working in granular soil with
a trench width less than 1:1 is considered an unsafe condition according
to OSHA regulations.
⩥ Type of Pump with Fixed Impeller Answer: A centrifugal pump
consists of an impeller fixed on a rotating shaft enclosed in a casing.
⩥ Purpose of a Check Valve Answer: A check valve is used to prevent
flow in a reverse direction.
⩥ Framework to Support Trench Walls Answer: Shoring is a complete
framework of wood and/or metal designated to support the walls of a
trench.
⩥ Issue with Improperly Adjusted Weighted Check Valve Answer:
Improperly adjusted weighted check valve can result in water hammer.
, ⩥ Protected Classes of Employees Answer: Protected classes of
employees include individuals over 40 years of age, gender, and political
affiliation.
⩥ Advantage of Gate Valves in Water Distribution Systems Answer:
Gate valves are used in water distribution systems due to their lower
friction compared to other valves.
⩥ Definition of Controlling Answer: Controlling involves ensuring
progress towards objectives and taking corrective actions as necessary.
⩥ Types of Maintenance in Preventative Maintenance Program Answer:
The four types of maintenance in a preventative maintenance program
are predictive maintenance, planned maintenance, and corrective
maintenance.
⩥ About how many gallons would a 6-inch pipeline, 1000 feet long
hold? Answer: Approximately 1500 gallons
⩥ Why is the objective of any safety program important? Answer: To
prevent accidents and ensure workplace safety
⩥ What is the chlorine residual in treated water with a dose of 2.1 mg/L
and a demand of 0.8 mg/L? Answer: Chlorine residual: 1.3 mg/L
