Texas Class D Water License – Class D
Wastewater Test Exam Certification (Graded
and Verified).
Operator treatment goals are defined by the limits and conditions in waste
discharge
A) Policies
B) Standards
C) Permits <<<Answer:
D) Inspections
According to TCEQ design criteria, wastewater collection lines should not be
installed any closer than 9 ft from a _____ line
A) Sewer
B) Drainage
C) Water <<<Answer:
D) Electric
Monthly reports of effluent quality are submitted to
A) EPA
B) Local council
C) Texas Commission on Environmental Quality (TCEQ) <<<Answer:
D) OSHA
A domestic wastewater plant operator must hold a valid license issued by
A) TWUA
B) TCEQ <<<Answer:
Page 1 of 42
,Texas Class D Water License – Class D
Wastewater Test Exam Certification (Graded
and Verified).
C) NRC
D) WHO
The National Pollutant Discharge Elimination System (NPDES) is enforced by
A) EPA <<<Answer:
B) CDC
C) WHO
D) FEMA
Section 2 – Preliminary Treatment
Screenings from a treatment plant should be
A) Incinerated onsite
B) Buried in a permitted sanitary landfill <<<Answer:
C) Recycled
D) Washed and reused
Which process is considered preliminary treatment?
A) Aeration
B) Grit removal <<<Answer:
C) Clarification
D) Disinfection
Page 2 of 42
,Texas Class D Water License – Class D
Wastewater Test Exam Certification (Graded
and Verified).
Comminutors and grinders are used to
A) Remove grit
B) Shred large solids <<<Answer:
C) Disinfect effluent
D) Mix sludge
The velocity in grit channels should be maintained around
A) 0.2 fps
B) 1.0 fps
C) 1.0 – 1.3 fps <<<Answer:
D) 2.5 fps
Grit chambers protect
A) Effluent quality
B) Downstream pumps and equipment <<<Answer:
C) Laboratory staff
D) Disinfection systems
Section 3 – Primary Treatment
Settling of solids occurs more rapidly in
A) Cold wastewater
B) Warm wastewater <<<Answer:
Page 3 of 42
, Texas Class D Water License – Class D
Wastewater Test Exam Certification (Graded
and Verified).
C) Salty wastewater
D) Chlorinated effluent
Primary clarifiers are designed to remove about what percent of BOD?
A) 10–15%
B) 25–35% <<<Answer:
C) 50%
D) 75%
Sludge blankets in primary clarifiers should be
A) 2–3 ft <<<Answer:
B) 6–8 ft
C) 10–12 ft
D) 0.5 ft
The typical detention time in a primary clarifier is
A) 15 min
B) 45 min
C) 1.5–2.5 hours <<<Answer:
D) 6 hours
Scum is composed mainly of
A) Sand
Page 4 of 42
Wastewater Test Exam Certification (Graded
and Verified).
Operator treatment goals are defined by the limits and conditions in waste
discharge
A) Policies
B) Standards
C) Permits <<<Answer:
D) Inspections
According to TCEQ design criteria, wastewater collection lines should not be
installed any closer than 9 ft from a _____ line
A) Sewer
B) Drainage
C) Water <<<Answer:
D) Electric
Monthly reports of effluent quality are submitted to
A) EPA
B) Local council
C) Texas Commission on Environmental Quality (TCEQ) <<<Answer:
D) OSHA
A domestic wastewater plant operator must hold a valid license issued by
A) TWUA
B) TCEQ <<<Answer:
Page 1 of 42
,Texas Class D Water License – Class D
Wastewater Test Exam Certification (Graded
and Verified).
C) NRC
D) WHO
The National Pollutant Discharge Elimination System (NPDES) is enforced by
A) EPA <<<Answer:
B) CDC
C) WHO
D) FEMA
Section 2 – Preliminary Treatment
Screenings from a treatment plant should be
A) Incinerated onsite
B) Buried in a permitted sanitary landfill <<<Answer:
C) Recycled
D) Washed and reused
Which process is considered preliminary treatment?
A) Aeration
B) Grit removal <<<Answer:
C) Clarification
D) Disinfection
Page 2 of 42
,Texas Class D Water License – Class D
Wastewater Test Exam Certification (Graded
and Verified).
Comminutors and grinders are used to
A) Remove grit
B) Shred large solids <<<Answer:
C) Disinfect effluent
D) Mix sludge
The velocity in grit channels should be maintained around
A) 0.2 fps
B) 1.0 fps
C) 1.0 – 1.3 fps <<<Answer:
D) 2.5 fps
Grit chambers protect
A) Effluent quality
B) Downstream pumps and equipment <<<Answer:
C) Laboratory staff
D) Disinfection systems
Section 3 – Primary Treatment
Settling of solids occurs more rapidly in
A) Cold wastewater
B) Warm wastewater <<<Answer:
Page 3 of 42
, Texas Class D Water License – Class D
Wastewater Test Exam Certification (Graded
and Verified).
C) Salty wastewater
D) Chlorinated effluent
Primary clarifiers are designed to remove about what percent of BOD?
A) 10–15%
B) 25–35% <<<Answer:
C) 50%
D) 75%
Sludge blankets in primary clarifiers should be
A) 2–3 ft <<<Answer:
B) 6–8 ft
C) 10–12 ft
D) 0.5 ft
The typical detention time in a primary clarifier is
A) 15 min
B) 45 min
C) 1.5–2.5 hours <<<Answer:
D) 6 hours
Scum is composed mainly of
A) Sand
Page 4 of 42
