Texas Wastewater B exam questions and
answers 2025\2026 A+ Grade
Primary Clarifiers
- correct answer In an activated sludge treatment system, primary treatment processes include the:
Removal of Inorganic material from grit
- correct answer In a washing grit remover, the grit is moved slowly by screw conveyors up an inclined
channel in order to?
90% or above
- correct answer An efficient primary clarifier is expected to remove ? of the influent settleable solids.
Adequate DO at surface at all times
- correct answer Proper operation of a facultative pond system requires that:,
True
- correct answer The amount of organic matter removed by a trickling filter is mostly dependent on the
recirculation ratio
Bulking
- correct answer In an activated sludge treatment plant, a Sludge Volume Index (SVI) of 180 would
indicate
Reseed The AB, Remove sludge from FC
- correct answer The purpose of returning the solids from the bottom of the clarifier to the aeration tank
in the activated sludge process is to
Free swimmer rotifers stalked ciliates
- correct answer Microscopic examination of a good-settling sludge should show a predominance of:
, Dissolved oxygen (DO) or oxygen obtained from food materials such as sulfate or nitrate
- correct answer When nitrification takes place in the activated sludge process, facultative bacteria use
Primary clarifiers
- correct answer In an activated sludge process, the results of a mixed liquor settling test indicate that
the supernatant of the mixed liquor sample is clear, but the supernatant of the plant effluent sample is
turbid. These test results indicate that the problem is occurring in the?
Low C02 high Methane
- correct answer One indication that an anaerobic digestion facility is improving would be?
False
- correct answer The terms "low rate" and "high rate" when used in reference to the anaerobic digester
refer to the rate of stabilization of the raw sludge?
Control odor, Reduce BOD ,Control foaming, Aid in sludge
- correct answer Besides disinfection, chlorination can be used in wastewater treatment processes to?
450ml
- correct answer If released to atmospheric pressure, one part liquid chlorine will expand to about?
8-12"
- correct answer Anaerobically digested sludge should be applied to a drying bed to a depth of about?
Not to create a negative pressure in the anaerobic digester and to prevent coning of sludge
- correct answer Sludge from a digester should be slowly drawn to a drying bed in order to?
Recharge Water supply, keep saline out of groundwater stop ground Substance
- correct answer Direct aquifer recharge of treated effluent can be used to?
under new construction, new plant, not running yet
- correct answer An exemption from filing monthly effluent reports with the TCEQ may be obtained if?
answers 2025\2026 A+ Grade
Primary Clarifiers
- correct answer In an activated sludge treatment system, primary treatment processes include the:
Removal of Inorganic material from grit
- correct answer In a washing grit remover, the grit is moved slowly by screw conveyors up an inclined
channel in order to?
90% or above
- correct answer An efficient primary clarifier is expected to remove ? of the influent settleable solids.
Adequate DO at surface at all times
- correct answer Proper operation of a facultative pond system requires that:,
True
- correct answer The amount of organic matter removed by a trickling filter is mostly dependent on the
recirculation ratio
Bulking
- correct answer In an activated sludge treatment plant, a Sludge Volume Index (SVI) of 180 would
indicate
Reseed The AB, Remove sludge from FC
- correct answer The purpose of returning the solids from the bottom of the clarifier to the aeration tank
in the activated sludge process is to
Free swimmer rotifers stalked ciliates
- correct answer Microscopic examination of a good-settling sludge should show a predominance of:
, Dissolved oxygen (DO) or oxygen obtained from food materials such as sulfate or nitrate
- correct answer When nitrification takes place in the activated sludge process, facultative bacteria use
Primary clarifiers
- correct answer In an activated sludge process, the results of a mixed liquor settling test indicate that
the supernatant of the mixed liquor sample is clear, but the supernatant of the plant effluent sample is
turbid. These test results indicate that the problem is occurring in the?
Low C02 high Methane
- correct answer One indication that an anaerobic digestion facility is improving would be?
False
- correct answer The terms "low rate" and "high rate" when used in reference to the anaerobic digester
refer to the rate of stabilization of the raw sludge?
Control odor, Reduce BOD ,Control foaming, Aid in sludge
- correct answer Besides disinfection, chlorination can be used in wastewater treatment processes to?
450ml
- correct answer If released to atmospheric pressure, one part liquid chlorine will expand to about?
8-12"
- correct answer Anaerobically digested sludge should be applied to a drying bed to a depth of about?
Not to create a negative pressure in the anaerobic digester and to prevent coning of sludge
- correct answer Sludge from a digester should be slowly drawn to a drying bed in order to?
Recharge Water supply, keep saline out of groundwater stop ground Substance
- correct answer Direct aquifer recharge of treated effluent can be used to?
under new construction, new plant, not running yet
- correct answer An exemption from filing monthly effluent reports with the TCEQ may be obtained if?
