WATER TREATMENT OPERATOR
LEVEL 1 SAMPLE QUESTIONS
(WATER OPERATOR CERTIFICATION
STUDY GUIDE)CORRECT 100%
What are the two important factors impacting the effectiveness of chlorination? -
ANSWERConcentration of chlorine and contact time
The treatment process that controls corrosion or scaling is known as what? -
ANSWERStabilization
Permanganate reactions are highly dependent on what factor? - ANSWERpH
It is hardest to kill the organism that causes what illness? - ANSWERCryptosporidiosis
Disinfection of water wells with free chlorine requires exposure for how long and at what
concentration? - ANSWER12 to 24 hours; 50mg/L
Flocculation basins are usually designed to provide for detention times of how long? -
ANSWER15 to 45 minutes
Alum works best in a pH range of what? - ANSWER5.8 to 7.5
What has little effect on colloidal particles because of their small size? -
ANSWERGravity
What natural electrical force keeps colloidal particles apart in water treatment? -
ANSWERZeta potential
What does the zeta potential measure? - ANSWERThe number of excess electrons
found on the surface of all particulate matter
What device collects the settled water as it leaves the sedimentation basin? -
ANSWERThe effluent launder
In solid-contact basins with fairly constant water quality parameters, how often should
the solids concentration be determined? - ANSWERAt least twice per day
What is the definition of decant? - ANSWERTo draw off the liquid from a vessel of any
size without stirring up bottom sedimentation
LEVEL 1 SAMPLE QUESTIONS
(WATER OPERATOR CERTIFICATION
STUDY GUIDE)CORRECT 100%
What are the two important factors impacting the effectiveness of chlorination? -
ANSWERConcentration of chlorine and contact time
The treatment process that controls corrosion or scaling is known as what? -
ANSWERStabilization
Permanganate reactions are highly dependent on what factor? - ANSWERpH
It is hardest to kill the organism that causes what illness? - ANSWERCryptosporidiosis
Disinfection of water wells with free chlorine requires exposure for how long and at what
concentration? - ANSWER12 to 24 hours; 50mg/L
Flocculation basins are usually designed to provide for detention times of how long? -
ANSWER15 to 45 minutes
Alum works best in a pH range of what? - ANSWER5.8 to 7.5
What has little effect on colloidal particles because of their small size? -
ANSWERGravity
What natural electrical force keeps colloidal particles apart in water treatment? -
ANSWERZeta potential
What does the zeta potential measure? - ANSWERThe number of excess electrons
found on the surface of all particulate matter
What device collects the settled water as it leaves the sedimentation basin? -
ANSWERThe effluent launder
In solid-contact basins with fairly constant water quality parameters, how often should
the solids concentration be determined? - ANSWERAt least twice per day
What is the definition of decant? - ANSWERTo draw off the liquid from a vessel of any
size without stirring up bottom sedimentation
