Water Treatment Operator Level 1 Sample Questions (Water Operator
Certification Study Guide)
What are the two important factors impacting the effectiveness of chlorination? - ANSWES✔️💫-
Concentration of chlorine and contact time
The treatment process that controls corrosion or scaling is known as what? - ANSWES✔️💫-Stabilization
Permanganate reactions are highly dependent on what factor? - ANSWES✔️💫-pH
It is hardest to kill the organism that causes what illness? - ANSWES✔️💫-Cryptosporidiosis
Disinfection of water wells with free chlorine requires exposure for how long and at what
concentration? - ANSWES✔️💫-12 to 24 hours; 50mg/L
Flocculation basins are usually designed to provide for detention times of how long? - ANSWES✔️💫-15
to 45 minutes
Alum works best in a pH range of what? - ANSWES✔️💫-5.8 to 7.5
What has little effect on colloidal particles because of their small size? - ANSWES✔️💫-Gravity
What natural electrical force keeps colloidal particles apart in water treatment? - ANSWES✔️💫-Zeta
potential
What does the zeta potential measure? - ANSWES✔️💫-The number of excess electrons found on the
surface of all particulate matter
What device collects the settled water as it leaves the sedimentation basin? - ANSWES✔️💫-The effluent
launder
, In solid-contact basins with fairly constant water quality parameters, how often should the solids
concentration be determined? - ANSWES✔️💫-At least twice per day
What is the definition of decant? - ANSWES✔️💫-To draw off the liquid from a vessel of any size without
stirring up bottom sedimentation
How often should sedimentation basins with mechanical sludge removal equipment be drained and
inspected? - ANSWES✔️💫-Once a year
What is the most important reason to reduce turbidity? - ANSWES✔️💫-To remove pathogens
What is the filtration flow rate through a manganese greensand pressure filter at 10 degrees C? -
ANSWES✔️💫-2 to 3 gpm/sq ft
When is a filter ripening? - ANSWES✔️💫-When it becomes more efficient in particle removal
Virgin greensand can be regenerated by soaking the filter bed for several hours in a chlorine solution of
what? - ANSWES✔️💫-100 mg/L
What precipitates can foul a cation exchange resin? - ANSWES✔️💫-Iron and manganese
What process works best for sequestering manganese? - ANSWES✔️💫-Polyphosphates and chlorine
Adding CO2 to water is known as what? - ANSWES✔️💫-Recarbonation
What must be done in the ion-exchange softening process once the resin can no longer soften water? -
ANSWES✔️💫-Regeneration
Certification Study Guide)
What are the two important factors impacting the effectiveness of chlorination? - ANSWES✔️💫-
Concentration of chlorine and contact time
The treatment process that controls corrosion or scaling is known as what? - ANSWES✔️💫-Stabilization
Permanganate reactions are highly dependent on what factor? - ANSWES✔️💫-pH
It is hardest to kill the organism that causes what illness? - ANSWES✔️💫-Cryptosporidiosis
Disinfection of water wells with free chlorine requires exposure for how long and at what
concentration? - ANSWES✔️💫-12 to 24 hours; 50mg/L
Flocculation basins are usually designed to provide for detention times of how long? - ANSWES✔️💫-15
to 45 minutes
Alum works best in a pH range of what? - ANSWES✔️💫-5.8 to 7.5
What has little effect on colloidal particles because of their small size? - ANSWES✔️💫-Gravity
What natural electrical force keeps colloidal particles apart in water treatment? - ANSWES✔️💫-Zeta
potential
What does the zeta potential measure? - ANSWES✔️💫-The number of excess electrons found on the
surface of all particulate matter
What device collects the settled water as it leaves the sedimentation basin? - ANSWES✔️💫-The effluent
launder
, In solid-contact basins with fairly constant water quality parameters, how often should the solids
concentration be determined? - ANSWES✔️💫-At least twice per day
What is the definition of decant? - ANSWES✔️💫-To draw off the liquid from a vessel of any size without
stirring up bottom sedimentation
How often should sedimentation basins with mechanical sludge removal equipment be drained and
inspected? - ANSWES✔️💫-Once a year
What is the most important reason to reduce turbidity? - ANSWES✔️💫-To remove pathogens
What is the filtration flow rate through a manganese greensand pressure filter at 10 degrees C? -
ANSWES✔️💫-2 to 3 gpm/sq ft
When is a filter ripening? - ANSWES✔️💫-When it becomes more efficient in particle removal
Virgin greensand can be regenerated by soaking the filter bed for several hours in a chlorine solution of
what? - ANSWES✔️💫-100 mg/L
What precipitates can foul a cation exchange resin? - ANSWES✔️💫-Iron and manganese
What process works best for sequestering manganese? - ANSWES✔️💫-Polyphosphates and chlorine
Adding CO2 to water is known as what? - ANSWES✔️💫-Recarbonation
What must be done in the ion-exchange softening process once the resin can no longer soften water? -
ANSWES✔️💫-Regeneration
