Texas Wastewater Class A Prep for wastewater class
A| Ques ons and answers| 2026
Seeding of BOD samples is necessary when samples
(All of the above) have a chlorine residual, have a previously been chlorinated, have been
subjected to high temperatures, contain high or low pH industrial wastes
When is blue-green algae the most dominant on a pond treatment system?
Summer
A 30-inch diameter wastewater interceptor is observed to be flowing half-full at about two
fps. The approximate volume of wastewater flowing through the pipe is 3.14x1.25 x 1.25 x 2
= 4.9 cfs x 449 = 2,200 gpm
c. 2,200 gallons per minute
A one-cylinder reciproca0ng sludge pump with a 10-inch bore and a 5-inch stroke pumps at
a rate of 50 cycles per minute. How many minutes must the pump be operated to pump
5,000 gallons of sludge? 3.14x0.416 x 0.416 x0.416 x 50 x7.48 = 84.5 gpm 5000 gal = 59,2min
84.5 gpm b. 29
60 minutes
If an exis0ng centrifugal pump motor is replaced with a motor with 25 percent more speed,
the motor horsepower required will increase by 1.25 x 1.25 x 1.25 = 1.95
95 percent
When must TCEQ be no0fied about expansions of a treatment facility?
Before construc0on
In an anaerobic digester, the percentage of methane and carbon dioxide gas content should
be
70% methane, 30% carbon dioxide
The temperature of an anaerobic digester should be maintained at a minimum of
95° F
What type of wastewater treatment operates in the endogenous bacteria growth phase?
Extended air
Why is recircula0on needed in a trickling filter?
,Keep the media wet Further reduce BOD All of the above (a, b, and c)
What type of fire ex0nguisher would be used on an electrical control panel that has been
de-energized?
Class A Class C (a and d)
Disinfec0on with chlorine is the most effec0ve at a pH of
6.0
The biomass on a normal func0oning RBC has what appearance?
Grey to brown and 0.05 to 0.1 inch thick
The sludge from a primary clarifier should percent solids?
4% to 6%
What is eutrophica0on in a pond system?
Enrichment with nitrogen and phosphorous Causes algae blooms (b and c)
How oCen should pH meters be calibrated?
Daily
In Texas, pH meters are required to be calibrated on how many buffers?
two
An industrial complex has a BOD discharge to the POTW of 500 pounds per day. The
popula0on equivalent of this industry is 500 lbs = 2,941 0.17 lbs BOD person
2941
The parameters of the BOD test are
5 days at 20° Cen0grade
Standard Dimension Ra0o in pvc pipe is defined as
Ra0o of OD pipe diameter to wall thickness
How should shoring be removed from a trench?
up from the boEom up
In low pressure sewer systems where each tap must have a grinder pump liC sta0on, sta0on
is considered to be
part of the collec0on system and the responsibility of the u0lity
Effec0ve communica0on depends on
, being a good listener
When designing a wastewater collec0on system, the engineer considers the popula0on for
how many years in the future?
50
According to 30 TAC Chapter 317, all pipe and fiFngs used in wastewater pressure shall have
a minimum psi pressure ra0ng of
150
The minimum velocity of flow in a wastewater line should be
2.0 fps
At a construc0on job site, as the roadway speed increases, the spacing between cones and
barricades should
increase
The major cause of wastewater line stoppages is
roots and grease
Carbon monoxide (CO) poisoning symptoms are
0ghtness in the chest nausea drowsiness and headache (all of the above)
The smallest pipe size for air recircula0on of a self-priming centrifugal pump is
1 inch
Dangerous gases in a confined space may not be detected with the physical senses because
some gases have no odor some gases may deaden the sense of smell some gases may
displace the oxygen (all of the above)
What are the dangerous gases a collec0on system worker might come into contact with?
CO2 CO НaS CH4 (all of the above)
On a construc0on job site, equipment booms must maintain at least how many feet of
clearance from overhead electric lines?
10
How should trench shoring be installed?
to above the top of the trench
When seFng work goals for an employee, the goals should be
A| Ques ons and answers| 2026
Seeding of BOD samples is necessary when samples
(All of the above) have a chlorine residual, have a previously been chlorinated, have been
subjected to high temperatures, contain high or low pH industrial wastes
When is blue-green algae the most dominant on a pond treatment system?
Summer
A 30-inch diameter wastewater interceptor is observed to be flowing half-full at about two
fps. The approximate volume of wastewater flowing through the pipe is 3.14x1.25 x 1.25 x 2
= 4.9 cfs x 449 = 2,200 gpm
c. 2,200 gallons per minute
A one-cylinder reciproca0ng sludge pump with a 10-inch bore and a 5-inch stroke pumps at
a rate of 50 cycles per minute. How many minutes must the pump be operated to pump
5,000 gallons of sludge? 3.14x0.416 x 0.416 x0.416 x 50 x7.48 = 84.5 gpm 5000 gal = 59,2min
84.5 gpm b. 29
60 minutes
If an exis0ng centrifugal pump motor is replaced with a motor with 25 percent more speed,
the motor horsepower required will increase by 1.25 x 1.25 x 1.25 = 1.95
95 percent
When must TCEQ be no0fied about expansions of a treatment facility?
Before construc0on
In an anaerobic digester, the percentage of methane and carbon dioxide gas content should
be
70% methane, 30% carbon dioxide
The temperature of an anaerobic digester should be maintained at a minimum of
95° F
What type of wastewater treatment operates in the endogenous bacteria growth phase?
Extended air
Why is recircula0on needed in a trickling filter?
,Keep the media wet Further reduce BOD All of the above (a, b, and c)
What type of fire ex0nguisher would be used on an electrical control panel that has been
de-energized?
Class A Class C (a and d)
Disinfec0on with chlorine is the most effec0ve at a pH of
6.0
The biomass on a normal func0oning RBC has what appearance?
Grey to brown and 0.05 to 0.1 inch thick
The sludge from a primary clarifier should percent solids?
4% to 6%
What is eutrophica0on in a pond system?
Enrichment with nitrogen and phosphorous Causes algae blooms (b and c)
How oCen should pH meters be calibrated?
Daily
In Texas, pH meters are required to be calibrated on how many buffers?
two
An industrial complex has a BOD discharge to the POTW of 500 pounds per day. The
popula0on equivalent of this industry is 500 lbs = 2,941 0.17 lbs BOD person
2941
The parameters of the BOD test are
5 days at 20° Cen0grade
Standard Dimension Ra0o in pvc pipe is defined as
Ra0o of OD pipe diameter to wall thickness
How should shoring be removed from a trench?
up from the boEom up
In low pressure sewer systems where each tap must have a grinder pump liC sta0on, sta0on
is considered to be
part of the collec0on system and the responsibility of the u0lity
Effec0ve communica0on depends on
, being a good listener
When designing a wastewater collec0on system, the engineer considers the popula0on for
how many years in the future?
50
According to 30 TAC Chapter 317, all pipe and fiFngs used in wastewater pressure shall have
a minimum psi pressure ra0ng of
150
The minimum velocity of flow in a wastewater line should be
2.0 fps
At a construc0on job site, as the roadway speed increases, the spacing between cones and
barricades should
increase
The major cause of wastewater line stoppages is
roots and grease
Carbon monoxide (CO) poisoning symptoms are
0ghtness in the chest nausea drowsiness and headache (all of the above)
The smallest pipe size for air recircula0on of a self-priming centrifugal pump is
1 inch
Dangerous gases in a confined space may not be detected with the physical senses because
some gases have no odor some gases may deaden the sense of smell some gases may
displace the oxygen (all of the above)
What are the dangerous gases a collec0on system worker might come into contact with?
CO2 CO НaS CH4 (all of the above)
On a construc0on job site, equipment booms must maintain at least how many feet of
clearance from overhead electric lines?
10
How should trench shoring be installed?
to above the top of the trench
When seFng work goals for an employee, the goals should be
