7/19/26, 11:39 AM Wastewater Operator - Class 1 - Certification Review - Spring 2025 Flashcards | Quizlet
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Wastewater Operator - Class 1 - Certification Review -
Spring 2025
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Flashcard sets Study guides
Wastewater Class A/1 practice Wastewater Operator Class 1 & 2 Pra... Class 1 Wastewater Treatment Test O... wastew
109 terms Teacher 178 terms 67 terms 92 terms
sierra_bliss Preview juanmaganajr73 Preview Norac123nec Preview kam
Terms in this set (535)
What are the typical removal percentages in primary - Settleable Solids = 90-95%
clarifiers?
- T.S.S. = 60-75%
( Settleable Solids / T.S.S. / B.O.D. )
- B.O.D. = 25-35%
In a wastewater treatment process, which zone is - Aerobic : Removes Biochemical Oxygen Demand ( B.O.D. )
required to remove each of the three; Nitrogen,
Phosphorus, Biochemical Oxygen Demand ( B.O.D. )? - Anoxic : Removes Nitrogen
( Aerobic / Anoxic / Anaerobic ) - Anaerobic : Removes Phosphorus
In an Imhoff Tank, how is a "Slot" cleaned out? "Chaining"
Typically a large logging chain is inserted and dragged back and forth, clearing
out any blockages.
At what point does an Imhoff Tank need to have sludge When the sludge gets within 18 inches of the slot.
removed?
What is the color and consistency of the sludge that Black & Gritty sludge
comes out of an Imhoff Tank?
What nuisance insect can be a problem if the sides of a Filter Fly / Psychoda
Trickling Filter are not regularly cleaned?
https://quizlet.com/1021540148/wastewater-operator-class-1-certification-review-spring-2025-flash-cards/ 1/12
, 7/19/26, 11:39 AM Wastewater Operator - Class 1 - Certification Review - Spring 2025 Flashcards | Quizlet
What piece of equipment is becoming more widely used Putting a spray nozzle at the end of the rotary arm to wash off the eggs and
to treat Filter Fly / Psychoda problems in Rotary Trickling larvae from the walls.
Filters?
What Natural Force is used to settle particles that are Gravity
denser than water in a Clarifier?
Why are Trickling Filters NOT true organics "filters"? The organics are "Consumed" by the bacteria in the Zoogleal film, NOT "Filtered"
out.
What part of a wastewater plant is an initial location to The Secondary Clarifier
spot problems in the treatment process?
That is where issues with your "bugs" will show up; when solids do not want to
settle to the bottom.
How is dissolved matter changed in order for it to be It is made Denser / Heavier than water
removed from wastewater flow?
What are the 2 compartments each for in an Imhoff Tank? - Top : Used for Sedimentation
- Bottom : Used for Digestion of sludge
How large should the side vents in an Imhoff Tank be? Large enough to allow operator access for sludge removal.
What are 4 common properties of Chlorine gas? - Color : Yellow-Green
( Color / Comparative Weight / Boiling Point Temp. / - Comparative Weight : 2.5x Heavier than air
Expansion Rate )
- Boiling Point Temp : -30.1° F
- Expansion Rate : Expands 450x its size when changing from liquid to gas
Which Emergency Kit should be used for a 150 lbs - 150 lbs cylinder = Emergency Kit "A"
cylinder of Chlorine vs a 1 Ton cylinder vs a Rail Car?
- 1 Ton cylinder = Emergency Kit "B"
- Rail Car = Emergency Kit "C"
At what temperature range do fusible plugs melt in order 155° F - 160° F
to prevent a cylinder from exploding?
What are the steps that should be taken immediately if 1. Get away from the manhole ( Do NOT even replace the lid )
noxious or toxic fumes are detected at a manhole
location before or just after opening the lid? 2. Contact Police Dept, Fire Dept, & Supervisor ( and any other emergency
support necessary )
( Examples : Rotten egg smell or gasoline smell )
What is the first step in designing or updating a security Identify all of the potential hazards at the plant.
program or emergency plan at a treatment plant?
https://quizlet.com/1021540148/wastewater-operator-class-1-certification-review-spring-2025-flash-cards/ 2/12
Science Earth Science Save
Wastewater Operator - Class 1 - Certification Review -
Spring 2025
Leave the first rating
Students also studied
Flashcard sets Study guides
Wastewater Class A/1 practice Wastewater Operator Class 1 & 2 Pra... Class 1 Wastewater Treatment Test O... wastew
109 terms Teacher 178 terms 67 terms 92 terms
sierra_bliss Preview juanmaganajr73 Preview Norac123nec Preview kam
Terms in this set (535)
What are the typical removal percentages in primary - Settleable Solids = 90-95%
clarifiers?
- T.S.S. = 60-75%
( Settleable Solids / T.S.S. / B.O.D. )
- B.O.D. = 25-35%
In a wastewater treatment process, which zone is - Aerobic : Removes Biochemical Oxygen Demand ( B.O.D. )
required to remove each of the three; Nitrogen,
Phosphorus, Biochemical Oxygen Demand ( B.O.D. )? - Anoxic : Removes Nitrogen
( Aerobic / Anoxic / Anaerobic ) - Anaerobic : Removes Phosphorus
In an Imhoff Tank, how is a "Slot" cleaned out? "Chaining"
Typically a large logging chain is inserted and dragged back and forth, clearing
out any blockages.
At what point does an Imhoff Tank need to have sludge When the sludge gets within 18 inches of the slot.
removed?
What is the color and consistency of the sludge that Black & Gritty sludge
comes out of an Imhoff Tank?
What nuisance insect can be a problem if the sides of a Filter Fly / Psychoda
Trickling Filter are not regularly cleaned?
https://quizlet.com/1021540148/wastewater-operator-class-1-certification-review-spring-2025-flash-cards/ 1/12
, 7/19/26, 11:39 AM Wastewater Operator - Class 1 - Certification Review - Spring 2025 Flashcards | Quizlet
What piece of equipment is becoming more widely used Putting a spray nozzle at the end of the rotary arm to wash off the eggs and
to treat Filter Fly / Psychoda problems in Rotary Trickling larvae from the walls.
Filters?
What Natural Force is used to settle particles that are Gravity
denser than water in a Clarifier?
Why are Trickling Filters NOT true organics "filters"? The organics are "Consumed" by the bacteria in the Zoogleal film, NOT "Filtered"
out.
What part of a wastewater plant is an initial location to The Secondary Clarifier
spot problems in the treatment process?
That is where issues with your "bugs" will show up; when solids do not want to
settle to the bottom.
How is dissolved matter changed in order for it to be It is made Denser / Heavier than water
removed from wastewater flow?
What are the 2 compartments each for in an Imhoff Tank? - Top : Used for Sedimentation
- Bottom : Used for Digestion of sludge
How large should the side vents in an Imhoff Tank be? Large enough to allow operator access for sludge removal.
What are 4 common properties of Chlorine gas? - Color : Yellow-Green
( Color / Comparative Weight / Boiling Point Temp. / - Comparative Weight : 2.5x Heavier than air
Expansion Rate )
- Boiling Point Temp : -30.1° F
- Expansion Rate : Expands 450x its size when changing from liquid to gas
Which Emergency Kit should be used for a 150 lbs - 150 lbs cylinder = Emergency Kit "A"
cylinder of Chlorine vs a 1 Ton cylinder vs a Rail Car?
- 1 Ton cylinder = Emergency Kit "B"
- Rail Car = Emergency Kit "C"
At what temperature range do fusible plugs melt in order 155° F - 160° F
to prevent a cylinder from exploding?
What are the steps that should be taken immediately if 1. Get away from the manhole ( Do NOT even replace the lid )
noxious or toxic fumes are detected at a manhole
location before or just after opening the lid? 2. Contact Police Dept, Fire Dept, & Supervisor ( and any other emergency
support necessary )
( Examples : Rotten egg smell or gasoline smell )
What is the first step in designing or updating a security Identify all of the potential hazards at the plant.
program or emergency plan at a treatment plant?
https://quizlet.com/1021540148/wastewater-operator-class-1-certification-review-spring-2025-flash-cards/ 2/12
