WATER TREATMENT ACTUAL EXAM
QUESTIONS AND COMPLETE STUDY GUIDE
2026
▶ Algal Blooms cause... Answer: Taste and odor problems, very short filter
runs, An increase in pH, depletion of dissolved oxygen, and organic
loading.
▶ TON Answer: Threshold odor number
▶ pH fluctuations Answer: Daytime pH goes up and Nighttime pH goes
down.
▶ Costs go up to maintain consistent pH because... Answer: We need to
add more chlorine & coagulants, or more soda ash or caustic to lower the
pH.
▶ Dissolved Oxygen Depletion Answer: bacteria feed/metabolize on dead
algal cells that causes oxygen to be used up, which in return causes sever
fish die offs.
▶ Increase in color & chlorination is known as... Answer: Organic Loading
▶ Trihalomethanes, Haloacetic Acids (HAA5s), Bromate, and Chlorite are
known as... Answer: disinfect byproducts that cause cancer
▶ MCL : TTHMs Answer: .08 ppm
▶ MCL: HAA5s Answer: .06 ppm
▶ MCL: Bromate Answer: .01 ppm
▶ MCL: Chlorite Answer: 1 ppm
▶ MRDLs Answer: Maximum Residual Detection Levels
, ▶ MRDL: Chlorine Answer: 4 ppm
▶ MRDL: Chloramines Answer: 4 ppm
▶ MRDL: Chlorine Dioxide Answer: .8 ppm
▶ D/DBP stage 1 Answer: Establishes a technique or enhanced
coagulation & softening and sets a Total Organic Carbon removal based on
the alkalinity of the raw water.
▶ D/DBP Stage 2 Answer: Establishes an initial Distribution Evaluation
and moves the sampling calculation to locational Running Annual Average.
▶ Monomictic Lakes Answer: One mixing in Warner climates
▶ Dimictic lakes Answer: Two mixings in colder climates
▶ Epilimnion Answer: An upper layer of warm water with high levels of
dissolved oxygen (upper part of a stratified reservior)
▶ Metalimnion / Thermocline Answer: middle layer in a stratified reservior
▶ Hypolimnion zone Answer: lower layer
▶ Biochemical oxygen demand (BOD) in the metalimnion & hypolimnion
causes... Answer: Anaerobic conditions: rotten egg odor, increase iron and
magnanese
▶ Microbial conditions include... Answer: Viruses, bacteria, and Giardia
(parasite)
▶ Nitrogen based fertilizers runoff into reserviors causing: Answer:
Eutrophic conditions
▶ Industrial Discharges such as.. Answer: mining operations produce:
Cyanide, asbestos, and in GW: solvents (TCE, PCE) and Perchlorate
QUESTIONS AND COMPLETE STUDY GUIDE
2026
▶ Algal Blooms cause... Answer: Taste and odor problems, very short filter
runs, An increase in pH, depletion of dissolved oxygen, and organic
loading.
▶ TON Answer: Threshold odor number
▶ pH fluctuations Answer: Daytime pH goes up and Nighttime pH goes
down.
▶ Costs go up to maintain consistent pH because... Answer: We need to
add more chlorine & coagulants, or more soda ash or caustic to lower the
pH.
▶ Dissolved Oxygen Depletion Answer: bacteria feed/metabolize on dead
algal cells that causes oxygen to be used up, which in return causes sever
fish die offs.
▶ Increase in color & chlorination is known as... Answer: Organic Loading
▶ Trihalomethanes, Haloacetic Acids (HAA5s), Bromate, and Chlorite are
known as... Answer: disinfect byproducts that cause cancer
▶ MCL : TTHMs Answer: .08 ppm
▶ MCL: HAA5s Answer: .06 ppm
▶ MCL: Bromate Answer: .01 ppm
▶ MCL: Chlorite Answer: 1 ppm
▶ MRDLs Answer: Maximum Residual Detection Levels
, ▶ MRDL: Chlorine Answer: 4 ppm
▶ MRDL: Chloramines Answer: 4 ppm
▶ MRDL: Chlorine Dioxide Answer: .8 ppm
▶ D/DBP stage 1 Answer: Establishes a technique or enhanced
coagulation & softening and sets a Total Organic Carbon removal based on
the alkalinity of the raw water.
▶ D/DBP Stage 2 Answer: Establishes an initial Distribution Evaluation
and moves the sampling calculation to locational Running Annual Average.
▶ Monomictic Lakes Answer: One mixing in Warner climates
▶ Dimictic lakes Answer: Two mixings in colder climates
▶ Epilimnion Answer: An upper layer of warm water with high levels of
dissolved oxygen (upper part of a stratified reservior)
▶ Metalimnion / Thermocline Answer: middle layer in a stratified reservior
▶ Hypolimnion zone Answer: lower layer
▶ Biochemical oxygen demand (BOD) in the metalimnion & hypolimnion
causes... Answer: Anaerobic conditions: rotten egg odor, increase iron and
magnanese
▶ Microbial conditions include... Answer: Viruses, bacteria, and Giardia
(parasite)
▶ Nitrogen based fertilizers runoff into reserviors causing: Answer:
Eutrophic conditions
▶ Industrial Discharges such as.. Answer: mining operations produce:
Cyanide, asbestos, and in GW: solvents (TCE, PCE) and Perchlorate
