Water Treatment Operator Level 1 Sample
Questions (Water Operator Certification
Study Guide) WITH WELL ELABORATED
ANSWERS 2026!!!
What are the two important factors impacting the effectiveness of chlorination? - ANSWER☑️⭐-
Concentration of chlorine and contact time
The treatment process that controls corrosion or scaling is known as what? - ANSWER☑️⭐-Stabilization
Permanganate reactions are highly dependent on what factor? - ANSWER☑️⭐-pH
It is hardest to kill the organism that causes what illness? - ANSWER☑️⭐-Cryptosporidiosis
Disinfection of water wells with free chlorine requires exposure for how long and at what
concentration? - ANSWER☑️⭐-12 to 24 hours; 50mg/L
Flocculation basins are usually designed to provide for detention times of how long? - ANSWER☑️⭐-15
to 45 minutes
Alum works best in a pH range of what? - ANSWER☑️⭐-5.8 to 7.5
What has little effect on colloidal particles because of their small size? - ANSWER☑️⭐-Gravity
What natural electrical force keeps colloidal particles apart in water treatment? - ANSWER☑️⭐-Zeta
potential
, What does the zeta potential measure? - ANSWER☑️⭐-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? - ANSWER☑️⭐-The effluent
launder
In solid-contact basins with fairly constant water quality parameters, how often should the solids
concentration be determined? - ANSWER☑️⭐-At least twice per day
What is the definition of decant? - ANSWER☑️⭐-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? - ANSWER☑️⭐-Once a year
What is the most important reason to reduce turbidity? - ANSWER☑️⭐-To remove pathogens
What is the filtration flow rate through a manganese greensand pressure filter at 10 degrees C? -
ANSWER☑️⭐-2 to 3 gpm/sq ft
When is a filter ripening? - ANSWER☑️⭐-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? - ANSWER☑️⭐-100 mg/L
What precipitates can foul a cation exchange resin? - ANSWER☑️⭐-Iron and manganese
What process works best for sequestering manganese? - ANSWER☑️⭐-Polyphosphates and chlorine
Questions (Water Operator Certification
Study Guide) WITH WELL ELABORATED
ANSWERS 2026!!!
What are the two important factors impacting the effectiveness of chlorination? - ANSWER☑️⭐-
Concentration of chlorine and contact time
The treatment process that controls corrosion or scaling is known as what? - ANSWER☑️⭐-Stabilization
Permanganate reactions are highly dependent on what factor? - ANSWER☑️⭐-pH
It is hardest to kill the organism that causes what illness? - ANSWER☑️⭐-Cryptosporidiosis
Disinfection of water wells with free chlorine requires exposure for how long and at what
concentration? - ANSWER☑️⭐-12 to 24 hours; 50mg/L
Flocculation basins are usually designed to provide for detention times of how long? - ANSWER☑️⭐-15
to 45 minutes
Alum works best in a pH range of what? - ANSWER☑️⭐-5.8 to 7.5
What has little effect on colloidal particles because of their small size? - ANSWER☑️⭐-Gravity
What natural electrical force keeps colloidal particles apart in water treatment? - ANSWER☑️⭐-Zeta
potential
, What does the zeta potential measure? - ANSWER☑️⭐-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? - ANSWER☑️⭐-The effluent
launder
In solid-contact basins with fairly constant water quality parameters, how often should the solids
concentration be determined? - ANSWER☑️⭐-At least twice per day
What is the definition of decant? - ANSWER☑️⭐-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? - ANSWER☑️⭐-Once a year
What is the most important reason to reduce turbidity? - ANSWER☑️⭐-To remove pathogens
What is the filtration flow rate through a manganese greensand pressure filter at 10 degrees C? -
ANSWER☑️⭐-2 to 3 gpm/sq ft
When is a filter ripening? - ANSWER☑️⭐-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? - ANSWER☑️⭐-100 mg/L
What precipitates can foul a cation exchange resin? - ANSWER☑️⭐-Iron and manganese
What process works best for sequestering manganese? - ANSWER☑️⭐-Polyphosphates and chlorine
