OTCO BASIC WASTEWATER Exam
Questions with Correct Solutions
Already Graded A+!!!Updated
2025/2026 New Syllabus Exam
Preparation Material<<LATEST
VERSION>>
What devices function combines the functions of a screen and a grinder? -
ANSWER ✓ Communitor
In a trickling filter, liquid waste runs over the media, the slime either falls off or is
washed off. What is this process called? - ANSWER ✓ Sloughing
What laboratory test does not provide data for process control in the treatment
system? - ANSWER ✓ Solids demand
What environment do anaerobic bacteria live and reproduce in? - ANSWER ✓ An
environment with no free or dissolved oxygen
When the carbon dioxide rises to the surface, some of it is used by algae, which
converts it to oxygen by the process of - ANSWER ✓ Photosynthesis
Changes in the wastewater blank can upset a biological unit by inhibiting or
killing the microorganisms. - ANSWER ✓ pH
Pressure is measured in terms of feet, expressed as the blank in elevation of the
course and discharge point of the liquid. - ANSWER ✓ Difference
Why is testing for water quality at a treatment plant important? - ANSWER ✓
Helps the plant remain compliant with is NPDES permit
, Some blank require sophisticated techniques or specialized equipment and testing
for these may be doe external commercial labs. - ANSWER ✓ Testing Parameters
Where are the ventilation ports generally located on a filter tower? - ANSWER ✓
Base
What important safety procedure must be completed before inspecting or servicing
a rotating distributor? - ANSWER ✓ Lock out and tag the influent valve or pump
supplying the flow and secure the distributor.
What will happen if grease and scum are not removed from the primary tanks
regularly? - ANSWER ✓ Down stream plant processes will be affected.
Comminutors and grinders are used in the headwork's of treatment plants to: -
ANSWER ✓ Shred and grin material entering the plant
What is or are some of the advantages of an aerated grit removal system? -
ANSWER ✓ Lighter organics in suspension, freshens wastewater, produces well-
washed grit, removes heavy material.
What might happen if in ground clarifiers are dewatered during high ground water
conditions? - ANSWER ✓ Tank will float.
Withdrawal rates in a primary clarifiers should be slow to prevent pulling out too
much blank with the sludge. - ANSWER ✓ Water
The key to any blank system, in a fixed film treatment, is to get the wastewater
evenly distributed over the media so that proper treatment can occur. - ANSWER
✓ Distribution
The blank starts with the person who collects the sample, continues through the
person who analyzes the sample in the laboratory, and ends at the person who
witnesses disposal of the sample. - ANSWER ✓ Chain of Custody
The blank of treated water back to the filter is probably the most important factor
used to effectively control trickling filter performance: - ANSWER ✓
Recirculation
Questions with Correct Solutions
Already Graded A+!!!Updated
2025/2026 New Syllabus Exam
Preparation Material<<LATEST
VERSION>>
What devices function combines the functions of a screen and a grinder? -
ANSWER ✓ Communitor
In a trickling filter, liquid waste runs over the media, the slime either falls off or is
washed off. What is this process called? - ANSWER ✓ Sloughing
What laboratory test does not provide data for process control in the treatment
system? - ANSWER ✓ Solids demand
What environment do anaerobic bacteria live and reproduce in? - ANSWER ✓ An
environment with no free or dissolved oxygen
When the carbon dioxide rises to the surface, some of it is used by algae, which
converts it to oxygen by the process of - ANSWER ✓ Photosynthesis
Changes in the wastewater blank can upset a biological unit by inhibiting or
killing the microorganisms. - ANSWER ✓ pH
Pressure is measured in terms of feet, expressed as the blank in elevation of the
course and discharge point of the liquid. - ANSWER ✓ Difference
Why is testing for water quality at a treatment plant important? - ANSWER ✓
Helps the plant remain compliant with is NPDES permit
, Some blank require sophisticated techniques or specialized equipment and testing
for these may be doe external commercial labs. - ANSWER ✓ Testing Parameters
Where are the ventilation ports generally located on a filter tower? - ANSWER ✓
Base
What important safety procedure must be completed before inspecting or servicing
a rotating distributor? - ANSWER ✓ Lock out and tag the influent valve or pump
supplying the flow and secure the distributor.
What will happen if grease and scum are not removed from the primary tanks
regularly? - ANSWER ✓ Down stream plant processes will be affected.
Comminutors and grinders are used in the headwork's of treatment plants to: -
ANSWER ✓ Shred and grin material entering the plant
What is or are some of the advantages of an aerated grit removal system? -
ANSWER ✓ Lighter organics in suspension, freshens wastewater, produces well-
washed grit, removes heavy material.
What might happen if in ground clarifiers are dewatered during high ground water
conditions? - ANSWER ✓ Tank will float.
Withdrawal rates in a primary clarifiers should be slow to prevent pulling out too
much blank with the sludge. - ANSWER ✓ Water
The key to any blank system, in a fixed film treatment, is to get the wastewater
evenly distributed over the media so that proper treatment can occur. - ANSWER
✓ Distribution
The blank starts with the person who collects the sample, continues through the
person who analyzes the sample in the laboratory, and ends at the person who
witnesses disposal of the sample. - ANSWER ✓ Chain of Custody
The blank of treated water back to the filter is probably the most important factor
used to effectively control trickling filter performance: - ANSWER ✓
Recirculation
