1
Texas Wastewater A Questions and
Correct Answers
What is TCEQ doing to control "point source" pollution
of the Texas waterways? Answer: *Permitting of
domestic wastewater plants
*Permitting of industrial wastewater plants
Describe proper design of force main wastewater lines.
Answer: Minimum two fps velocity with the smallest
pump operating alone. Minimum four inch diameter
pipe with 150 psi rating.
What is Standard Dimension Ratio? Answer: Ratio of
outside pipe diameter (OD) to wall thickness (PVC)
Describe proper design of gravity wastewater lines.
Answer: Designed to flow half full ,under normal
conditions, at a minimum of two fps and a maximum of
ten fps.
Manholes should have a minimum opening of?
Answer: 24 inches and be at least 4 feet wide.
Pretest - Stuvia US
,2
pH meters should be calibrated how often? What
standards should be used for calibration purposes?
Answer: Daily with at least two buffers.
What is the standard chlorine residual and minimum
contact time on Texas wastewater permits? Answer:
a. 1.0 mg/L for a minimum 20 minutes detention time
at peak flow b. No chlorine residual needed if detention
time is greater than 21 days
As the complexity of an organization increases, what
management function becomes most important?
Answer: Planning
What is the effective chlorine disinfecting agent?
Answer: Hypochlorous Acid (HOCl)
Does pH affect the chlorination process? Explain your
answer. Answer: When using free chlorine the
disinfectant is HOCl acid. As such it is much more
effective at pH's below 7.0. Above 7.0 pH the acid
begins to be neutralized.
Pretest - Stuvia US
, 3
What is the effluent chlorine residual in Texas that is
standard on permits and the minimum detention time?
What is the maximum residual allowed? Answer:
Texas standard is 1.0 mg/L for a minimum 20 minutes
detention time at peak flow. Maximum residual allowed
is 4.0 mg/L.
A treatment plant has a clarifier that is 60 feet in
diameter and is 10 feet deep. The weir is 2 feet inside
the outer clarifier wall. The flow is 1.0 MGD. The weir
and outflow channel is 3 feet deep. a. What is the
detention time in hours? Answer: Formula
What activated process cannot nitrify in a single stage?
Answer: Contact Stabilization
What is the GPM output of a piston pump with an 8-
inch diameter piston with a 10-inch stroke operating at
50 strokes per minute? Answer: Formula
A treatment plant has a clarifier that is 60 feet in
diameter and is 10 feet deep. The weir is 2 feet inside
the outer clarifier wall. The flow is 1.0 MGD. The weir
and outflow channel is 3 feet deep.
Pretest - Stuvia US
Texas Wastewater A Questions and
Correct Answers
What is TCEQ doing to control "point source" pollution
of the Texas waterways? Answer: *Permitting of
domestic wastewater plants
*Permitting of industrial wastewater plants
Describe proper design of force main wastewater lines.
Answer: Minimum two fps velocity with the smallest
pump operating alone. Minimum four inch diameter
pipe with 150 psi rating.
What is Standard Dimension Ratio? Answer: Ratio of
outside pipe diameter (OD) to wall thickness (PVC)
Describe proper design of gravity wastewater lines.
Answer: Designed to flow half full ,under normal
conditions, at a minimum of two fps and a maximum of
ten fps.
Manholes should have a minimum opening of?
Answer: 24 inches and be at least 4 feet wide.
Pretest - Stuvia US
,2
pH meters should be calibrated how often? What
standards should be used for calibration purposes?
Answer: Daily with at least two buffers.
What is the standard chlorine residual and minimum
contact time on Texas wastewater permits? Answer:
a. 1.0 mg/L for a minimum 20 minutes detention time
at peak flow b. No chlorine residual needed if detention
time is greater than 21 days
As the complexity of an organization increases, what
management function becomes most important?
Answer: Planning
What is the effective chlorine disinfecting agent?
Answer: Hypochlorous Acid (HOCl)
Does pH affect the chlorination process? Explain your
answer. Answer: When using free chlorine the
disinfectant is HOCl acid. As such it is much more
effective at pH's below 7.0. Above 7.0 pH the acid
begins to be neutralized.
Pretest - Stuvia US
, 3
What is the effluent chlorine residual in Texas that is
standard on permits and the minimum detention time?
What is the maximum residual allowed? Answer:
Texas standard is 1.0 mg/L for a minimum 20 minutes
detention time at peak flow. Maximum residual allowed
is 4.0 mg/L.
A treatment plant has a clarifier that is 60 feet in
diameter and is 10 feet deep. The weir is 2 feet inside
the outer clarifier wall. The flow is 1.0 MGD. The weir
and outflow channel is 3 feet deep. a. What is the
detention time in hours? Answer: Formula
What activated process cannot nitrify in a single stage?
Answer: Contact Stabilization
What is the GPM output of a piston pump with an 8-
inch diameter piston with a 10-inch stroke operating at
50 strokes per minute? Answer: Formula
A treatment plant has a clarifier that is 60 feet in
diameter and is 10 feet deep. The weir is 2 feet inside
the outer clarifier wall. The flow is 1.0 MGD. The weir
and outflow channel is 3 feet deep.
Pretest - Stuvia US
