Saskatchewan Wastewater Operator j j
Level III Exam Questions And Correct Ans
j j j j j j j
wers (Verified Answers) Plus Rationales
j j j j j
2026 Q&A | Instant Download Pdf
j j j j j
1. jWhatjisjthejprimaryjpurposejofjajwastewaterjtreatmentjplant?
a) Producejpotablejwater
b) Protectjpublicjhealthjandjthejenvironmentjbyjtreatingjwastewater
c) Generatejelectricity
d) Providejirrigationjwater
Rationale:jThejmainjgoaljofjwastewaterjtreatmentjisjtojremovejconta
minantsjandjprotectjpublicjhealthjandjthejenvironment.
2. Whichjparameterjisjmostjcommonlyjusedjtojmeasurejorganicjstrengthji
njwastewater?
a) pH
, b) BiochemicaljOxygenjDemandj(BOD)
c) TotaljSuspendedjSolidsj(TSS)
d) Conductivity
Rationale:jBODjmeasuresjthejamountjofjoxygenjrequiredjbyjmicroorg
anismsjtojdecomposejorganicjmatterjinjwastewater.
3. WhatjisjthejtypicaljrangejofjpHjinjtreatedjmunicipaljwastewaterjd
ischarge?
a) 3–5
b) 6–7
c) 6.5–9
d) 9–11
Rationale:jTreatedjwastewaterjshouldjgenerallyjhavejajpHjnearjneutr
al,jusuallyjbetweenj6.5jandj9.
4. Whatjtypejofjmicroorganismjisjprimarilyjresponsiblejforjnitrificationjinj
wastewater?
a) Anaerobicjbacteria
b) Chemolithotrophicjbacteria
c) Protozoa
d) Fungi
Rationale:jNitrifyingjbacteria,jsuchjasjNitrosomonasjandjNitrobacter,j
oxidizejammoniajtojnitrate.
5. Injactivatedjsludge,jwhatjdoesjthejtermj“sludgejage”jreferjto?
a) Agejofjthejinfluentjwastewater
, b) Timejsludgejspendsjinjthejprimaryjclarifier
c) Averagejtimejmicroorganismsjremainjinjthejsystem
d) Timejforjsludgejtojsettlejinjthejdigester
Rationale:jSludgejagej(orjsolidsjretentionjtime)jisjthejaveragej
durationjmicroorganismsjstayjinjthejactivatedjsludgejsystem,j
affectingjtreatmentjefficiency.
6. Whichjofjthejfollowingjisjajcommonjmethodjofjremovingjsolidsjfromjw
astewater?
a) Sedimentation
b) Filtration
c) Chlorination
d) Aeration
Rationale:jSedimentationjallowsjsolidsjtojsettlejoutjbyjgravityjinjclarifi
ersjorjsettlingjtanks.
7. Whatjisjthejmainjpurposejofjchlorinationjinjwastewaterjtreatment?
a) ReducejBOD
b) Removejsolids
c) Disinfectjandjkilljpathogens
d) Enhancejsettling
Rationale:jChlorinationjisjusedjprimarilyjforjdisinfectionjtojkillj
disease-causingjorganisms.
8. Whichjofjthejfollowingjisjajcharacteristicjofjanaerobicjdigestion?
a) Requiresjoxygen
, b) Producesjnitrate
c) Producesjmethanejgas
d) RapidlyjreducesjTSSjwithoutjodor
Rationale:jAnaerobicjdigestionjdecomposesjorganicjmatterjinjthejabse
ncejofjoxygen,jproducingjmethanejandjCO₂.
9. Whatjisjthejpurposejofjajgritjchamber?
a) ReducejBOD
b) Removejsand,jgravel,jandjotherjheavyjinorganicjsolids
c) Aeratejwastewater
d) NeutralizejpH
Rationale:jGritjchambersjremovejdensejinorganicjparticlesjtojpreventj
damagejtojdownstreamjequipment.
10. Whatjisjthejtypicaljtemperaturejrangejforjmesophilicjanaerobicj
digestion?
a) 5–15°C
b) 30–38°C
c) 50–60°C
d) 70–80°C
Rationale:jMesophilicjdigestionjoccursjefficientlyjinjthejrangejofj30–
j38°C.
11. Whichjsludgejdewateringjprocessjusesjhigh-
speedjcentrifugaljforce?
a) Beltjpress
Level III Exam Questions And Correct Ans
j j j j j j j
wers (Verified Answers) Plus Rationales
j j j j j
2026 Q&A | Instant Download Pdf
j j j j j
1. jWhatjisjthejprimaryjpurposejofjajwastewaterjtreatmentjplant?
a) Producejpotablejwater
b) Protectjpublicjhealthjandjthejenvironmentjbyjtreatingjwastewater
c) Generatejelectricity
d) Providejirrigationjwater
Rationale:jThejmainjgoaljofjwastewaterjtreatmentjisjtojremovejconta
minantsjandjprotectjpublicjhealthjandjthejenvironment.
2. Whichjparameterjisjmostjcommonlyjusedjtojmeasurejorganicjstrengthji
njwastewater?
a) pH
, b) BiochemicaljOxygenjDemandj(BOD)
c) TotaljSuspendedjSolidsj(TSS)
d) Conductivity
Rationale:jBODjmeasuresjthejamountjofjoxygenjrequiredjbyjmicroorg
anismsjtojdecomposejorganicjmatterjinjwastewater.
3. WhatjisjthejtypicaljrangejofjpHjinjtreatedjmunicipaljwastewaterjd
ischarge?
a) 3–5
b) 6–7
c) 6.5–9
d) 9–11
Rationale:jTreatedjwastewaterjshouldjgenerallyjhavejajpHjnearjneutr
al,jusuallyjbetweenj6.5jandj9.
4. Whatjtypejofjmicroorganismjisjprimarilyjresponsiblejforjnitrificationjinj
wastewater?
a) Anaerobicjbacteria
b) Chemolithotrophicjbacteria
c) Protozoa
d) Fungi
Rationale:jNitrifyingjbacteria,jsuchjasjNitrosomonasjandjNitrobacter,j
oxidizejammoniajtojnitrate.
5. Injactivatedjsludge,jwhatjdoesjthejtermj“sludgejage”jreferjto?
a) Agejofjthejinfluentjwastewater
, b) Timejsludgejspendsjinjthejprimaryjclarifier
c) Averagejtimejmicroorganismsjremainjinjthejsystem
d) Timejforjsludgejtojsettlejinjthejdigester
Rationale:jSludgejagej(orjsolidsjretentionjtime)jisjthejaveragej
durationjmicroorganismsjstayjinjthejactivatedjsludgejsystem,j
affectingjtreatmentjefficiency.
6. Whichjofjthejfollowingjisjajcommonjmethodjofjremovingjsolidsjfromjw
astewater?
a) Sedimentation
b) Filtration
c) Chlorination
d) Aeration
Rationale:jSedimentationjallowsjsolidsjtojsettlejoutjbyjgravityjinjclarifi
ersjorjsettlingjtanks.
7. Whatjisjthejmainjpurposejofjchlorinationjinjwastewaterjtreatment?
a) ReducejBOD
b) Removejsolids
c) Disinfectjandjkilljpathogens
d) Enhancejsettling
Rationale:jChlorinationjisjusedjprimarilyjforjdisinfectionjtojkillj
disease-causingjorganisms.
8. Whichjofjthejfollowingjisjajcharacteristicjofjanaerobicjdigestion?
a) Requiresjoxygen
, b) Producesjnitrate
c) Producesjmethanejgas
d) RapidlyjreducesjTSSjwithoutjodor
Rationale:jAnaerobicjdigestionjdecomposesjorganicjmatterjinjthejabse
ncejofjoxygen,jproducingjmethanejandjCO₂.
9. Whatjisjthejpurposejofjajgritjchamber?
a) ReducejBOD
b) Removejsand,jgravel,jandjotherjheavyjinorganicjsolids
c) Aeratejwastewater
d) NeutralizejpH
Rationale:jGritjchambersjremovejdensejinorganicjparticlesjtojpreventj
damagejtojdownstreamjequipment.
10. Whatjisjthejtypicaljtemperaturejrangejforjmesophilicjanaerobicj
digestion?
a) 5–15°C
b) 30–38°C
c) 50–60°C
d) 70–80°C
Rationale:jMesophilicjdigestionjoccursjefficientlyjinjthejrangejofj30–
j38°C.
11. Whichjsludgejdewateringjprocessjusesjhigh-
speedjcentrifugaljforce?
a) Beltjpress
