GEORGIA CERTIFIED OPERATORS
EXAM QUESTIONS AND FULLY
CORRECT ANSWERS
300 QUESTIONS AND ANSWERS
1. Q: What is the primary purpose of coagulation in water treatment? A:
To destabilize suspended particles and colloidal matter so they can form larger
flocs that can be removed by sedimentation and filtration.
2. Q: What is the optimal pH range for alum coagulation? A: 6.0 to 7.5
3. Q: What does turbidity measure? A: The cloudiness or haziness of water
caused by suspended particles.
4. Q: What is the maximum allowable turbidity for filtered water under the
Surface Water Treatment Rule? A: 1.0 NTU for conventional filtration, with
95% of readings ≤ 0.3 NTU.
5. Q: What is the detention time? A: The theoretical time required for a given
flow of water to pass through a tank or basin.
6. Q: How do you calculate detention time? A: Detention Time = Volume ÷
Flow Rate
7. Q: What is the purpose of disinfection in water treatment? A: To kill or
inactivate pathogenic microorganisms to prevent waterborne diseases.
8. Q: What is the most common disinfectant used in water treatment? A:
Chlorine (as gas, sodium hypochlorite, or calcium hypochlorite).
9. Q: What is free chlorine residual? A: The amount of chlorine available for
disinfection after the chlorine demand has been satisfied.
10. Q: What is combined chlorine residual? A: Chlorine that has reacted with
ammonia or organic nitrogen compounds to form chloramines.
,11. Q: What is breakpoint chlorination? A: The point at which enough
chlorine has been added to oxidize all organic matter and ammonia, leaving
only free chlorine residual.
12. Q: What is the minimum free chlorine residual required in the
distribution system? A: 0.2 mg/L (Georgia requirement may vary, check
current regulations).
13. Q: What is hardness in water? A: The concentration of calcium and
magnesium ions in water, typically expressed as mg/L or ppm as CaCO₃.
14. Q: What is alkalinity? A: The capacity of water to neutralize acids,
primarily due to bicarbonates, carbonates, and hydroxides.
15. Q: What is pH? A: A measure of the hydrogen ion concentration in water,
indicating acidity or basicity on a scale of 0-14.
16. Q: What is the acceptable pH range for drinking water? A: 6.5 to 8.5
17. Q: What is fluoride used for in water treatment? A: To prevent tooth
decay when added at optimal levels (typically 0.7-1.2 mg/L).
18. Q: What is the maximum contaminant level (MCL) for fluoride? A: 4.0
mg/L
19. Q: What is iron and manganese removal typically accomplished by? A:
Oxidation followed by filtration.
20. Q: What is the taste and odor threshold for chlorine? A: Approximately
0.2-0.4 mg/L for most people.
21. Q: What is jar testing used for? A: To determine optimal coagulant
dosage and pH for water treatment.
22. Q: What is flocculation? A: The process of gentle mixing to promote the
formation of larger floc particles from smaller ones.
23. Q: What is sedimentation? A: The process of allowing floc particles to
settle out of water by gravity.
24. Q: What is filtration? A: The physical process of removing suspended
solids from water by passing it through a porous medium.
25. Q: What are the main types of filters used in water treatment? A: Rapid
sand filters, slow sand filters, dual media filters, and multimedia filters.
26. Q: What is backwashing? A: The process of reversing flow through a filter
to remove accumulated solids and restore filtration capacity.
, 27. Q: What is filter head loss? A: The pressure drop across a filter due to the
resistance of the filter media and accumulated solids.
28. Q: What is the purpose of pre-chlorination? A: To control algae growth,
reduce taste and odor, and aid in coagulation.
29. Q: What is post-chlorination? A: Final disinfection to maintain residual
chlorine in the distribution system.
30. Q: What is chlorine demand? A: The amount of chlorine required to react
with organic matter and other substances before free chlorine residual appears.
31. Q: What is contact time (CT)? A: The product of free chlorine
concentration and contact time, used to determine disinfection effectiveness.
32. Q: What is Giardia lamblia? A: A protozoan parasite that causes
giardiasis and is resistant to chlorine disinfection.
33. Q: What is Cryptosporidium? A: A protozoan parasite that causes
cryptosporidiosis and is highly resistant to chlorine disinfection.
34. Q: What is the log removal requirement for Giardia? A: 3-log (99.9%)
removal/inactivation.
35. Q: What is the log removal requirement for viruses? A: 4-log (99.99%)
removal/inactivation.
36. Q: What is ozone used for in water treatment? A: Disinfection and
oxidation of organic compounds, iron, and manganese.
37. Q: What is ultraviolet (UV) disinfection? A: A physical disinfection
process that uses UV light to inactivate microorganisms.
38. Q: What is granular activated carbon (GAC) used for? A: Removal of
taste, odor, and organic compounds through adsorption.
39. Q: What is powdered activated carbon (PAC) used for? A: Temporary
taste and odor control and removal of organic compounds.
40. Q: What is membrane filtration? A: A physical separation process using
semi-permeable membranes to remove contaminants.
41. Q: What is reverse osmosis? A: A membrane process that removes
dissolved solids, including salts and minerals.
42. Q: What is nanofiltration? A: A membrane process that removes organic
compounds and multivalent ions.
EXAM QUESTIONS AND FULLY
CORRECT ANSWERS
300 QUESTIONS AND ANSWERS
1. Q: What is the primary purpose of coagulation in water treatment? A:
To destabilize suspended particles and colloidal matter so they can form larger
flocs that can be removed by sedimentation and filtration.
2. Q: What is the optimal pH range for alum coagulation? A: 6.0 to 7.5
3. Q: What does turbidity measure? A: The cloudiness or haziness of water
caused by suspended particles.
4. Q: What is the maximum allowable turbidity for filtered water under the
Surface Water Treatment Rule? A: 1.0 NTU for conventional filtration, with
95% of readings ≤ 0.3 NTU.
5. Q: What is the detention time? A: The theoretical time required for a given
flow of water to pass through a tank or basin.
6. Q: How do you calculate detention time? A: Detention Time = Volume ÷
Flow Rate
7. Q: What is the purpose of disinfection in water treatment? A: To kill or
inactivate pathogenic microorganisms to prevent waterborne diseases.
8. Q: What is the most common disinfectant used in water treatment? A:
Chlorine (as gas, sodium hypochlorite, or calcium hypochlorite).
9. Q: What is free chlorine residual? A: The amount of chlorine available for
disinfection after the chlorine demand has been satisfied.
10. Q: What is combined chlorine residual? A: Chlorine that has reacted with
ammonia or organic nitrogen compounds to form chloramines.
,11. Q: What is breakpoint chlorination? A: The point at which enough
chlorine has been added to oxidize all organic matter and ammonia, leaving
only free chlorine residual.
12. Q: What is the minimum free chlorine residual required in the
distribution system? A: 0.2 mg/L (Georgia requirement may vary, check
current regulations).
13. Q: What is hardness in water? A: The concentration of calcium and
magnesium ions in water, typically expressed as mg/L or ppm as CaCO₃.
14. Q: What is alkalinity? A: The capacity of water to neutralize acids,
primarily due to bicarbonates, carbonates, and hydroxides.
15. Q: What is pH? A: A measure of the hydrogen ion concentration in water,
indicating acidity or basicity on a scale of 0-14.
16. Q: What is the acceptable pH range for drinking water? A: 6.5 to 8.5
17. Q: What is fluoride used for in water treatment? A: To prevent tooth
decay when added at optimal levels (typically 0.7-1.2 mg/L).
18. Q: What is the maximum contaminant level (MCL) for fluoride? A: 4.0
mg/L
19. Q: What is iron and manganese removal typically accomplished by? A:
Oxidation followed by filtration.
20. Q: What is the taste and odor threshold for chlorine? A: Approximately
0.2-0.4 mg/L for most people.
21. Q: What is jar testing used for? A: To determine optimal coagulant
dosage and pH for water treatment.
22. Q: What is flocculation? A: The process of gentle mixing to promote the
formation of larger floc particles from smaller ones.
23. Q: What is sedimentation? A: The process of allowing floc particles to
settle out of water by gravity.
24. Q: What is filtration? A: The physical process of removing suspended
solids from water by passing it through a porous medium.
25. Q: What are the main types of filters used in water treatment? A: Rapid
sand filters, slow sand filters, dual media filters, and multimedia filters.
26. Q: What is backwashing? A: The process of reversing flow through a filter
to remove accumulated solids and restore filtration capacity.
, 27. Q: What is filter head loss? A: The pressure drop across a filter due to the
resistance of the filter media and accumulated solids.
28. Q: What is the purpose of pre-chlorination? A: To control algae growth,
reduce taste and odor, and aid in coagulation.
29. Q: What is post-chlorination? A: Final disinfection to maintain residual
chlorine in the distribution system.
30. Q: What is chlorine demand? A: The amount of chlorine required to react
with organic matter and other substances before free chlorine residual appears.
31. Q: What is contact time (CT)? A: The product of free chlorine
concentration and contact time, used to determine disinfection effectiveness.
32. Q: What is Giardia lamblia? A: A protozoan parasite that causes
giardiasis and is resistant to chlorine disinfection.
33. Q: What is Cryptosporidium? A: A protozoan parasite that causes
cryptosporidiosis and is highly resistant to chlorine disinfection.
34. Q: What is the log removal requirement for Giardia? A: 3-log (99.9%)
removal/inactivation.
35. Q: What is the log removal requirement for viruses? A: 4-log (99.99%)
removal/inactivation.
36. Q: What is ozone used for in water treatment? A: Disinfection and
oxidation of organic compounds, iron, and manganese.
37. Q: What is ultraviolet (UV) disinfection? A: A physical disinfection
process that uses UV light to inactivate microorganisms.
38. Q: What is granular activated carbon (GAC) used for? A: Removal of
taste, odor, and organic compounds through adsorption.
39. Q: What is powdered activated carbon (PAC) used for? A: Temporary
taste and odor control and removal of organic compounds.
40. Q: What is membrane filtration? A: A physical separation process using
semi-permeable membranes to remove contaminants.
41. Q: What is reverse osmosis? A: A membrane process that removes
dissolved solids, including salts and minerals.
42. Q: What is nanofiltration? A: A membrane process that removes organic
compounds and multivalent ions.
