WATER TREATMENT OIT TEST 300 MOCK TEST
WITH ANSWER RATIONALES 2026
◉ What is the object of O. Reg. 170/03?
Answer: Drinking Water Systems Regulations:
Sampling, Testing, Reporting Adverse Tests, Min level of treatment
for GW and SW.
◉ What is the object of O. Reg. 248/03?
Answer: Testing Regulation:
Regulates; Sampling, Testing, Analysis, handling, creates a licensing
system for labs.
◉ What is the object of O. Reg. 128/04 and O. Reg. 129/04?
Answer: Controls Licensing
◉ What major regulations are contained under the Ontario Water
Resources Act
(OWRA)?
Answer: Reg 285, 129, 903
◉ What is the object of O. Reg. 285/99?
,Answer: Permits for water taking and transfer
◉ What is the object of O. Reg. 903?
Answer: Wells
◉ Physical Characteristics
Answer: Temperature, Colour, Suspended Solids, Turbidity
◉ Chemical Characteristics
Answer: Nutrients, minerals, metals, oxygen, organic compounds
◉ Biological Characteristics
Answer: Aquatic plants, animals, algae, bacteria, protozoa
◉ What is the minimum level of treatment for surface water?
Answer: Chemical assisted filtration, Primary disinfection
◉ What is the minimum level for treatment for GUDI water?
Answer: Same as surface:
Chemical assisted filtration, disinfection
◉ Why is surface water quality so variable?
, Answer: No single or simple measure of quality
Contain a wide variety of substances
◉ Why are lakes and reservoirs usually sources of better quality
water than rivers?
Answer: Suspended matter settles at the bottom and natural
purification processes have time to improve water.
◉ What is thermal stratification
Answer: Changes in temperature profile with depth in a lake
◉ What is eutrophication?
Answer: High nutrient loading in lakes and rivers. Can come from
nitrogen and phosphorus due to wastewater discharges.
◉ What is presedimentation?
Answer: Removes gravel, sand, silt prior to main treatment
◉ What is coagulation?
Answer: Rapid dispersion of coagulant in water to destabilize
particles and form precipitates
◉ What is flocculation?
WITH ANSWER RATIONALES 2026
◉ What is the object of O. Reg. 170/03?
Answer: Drinking Water Systems Regulations:
Sampling, Testing, Reporting Adverse Tests, Min level of treatment
for GW and SW.
◉ What is the object of O. Reg. 248/03?
Answer: Testing Regulation:
Regulates; Sampling, Testing, Analysis, handling, creates a licensing
system for labs.
◉ What is the object of O. Reg. 128/04 and O. Reg. 129/04?
Answer: Controls Licensing
◉ What major regulations are contained under the Ontario Water
Resources Act
(OWRA)?
Answer: Reg 285, 129, 903
◉ What is the object of O. Reg. 285/99?
,Answer: Permits for water taking and transfer
◉ What is the object of O. Reg. 903?
Answer: Wells
◉ Physical Characteristics
Answer: Temperature, Colour, Suspended Solids, Turbidity
◉ Chemical Characteristics
Answer: Nutrients, minerals, metals, oxygen, organic compounds
◉ Biological Characteristics
Answer: Aquatic plants, animals, algae, bacteria, protozoa
◉ What is the minimum level of treatment for surface water?
Answer: Chemical assisted filtration, Primary disinfection
◉ What is the minimum level for treatment for GUDI water?
Answer: Same as surface:
Chemical assisted filtration, disinfection
◉ Why is surface water quality so variable?
, Answer: No single or simple measure of quality
Contain a wide variety of substances
◉ Why are lakes and reservoirs usually sources of better quality
water than rivers?
Answer: Suspended matter settles at the bottom and natural
purification processes have time to improve water.
◉ What is thermal stratification
Answer: Changes in temperature profile with depth in a lake
◉ What is eutrophication?
Answer: High nutrient loading in lakes and rivers. Can come from
nitrogen and phosphorus due to wastewater discharges.
◉ What is presedimentation?
Answer: Removes gravel, sand, silt prior to main treatment
◉ What is coagulation?
Answer: Rapid dispersion of coagulant in water to destabilize
particles and form precipitates
◉ What is flocculation?
