OPERATION OF WASTEWATER
TREATMENT PLANTS LEVELS 1-2 EXAM
PREP COMPLETE DETAILED CASE
STUDY
An lImhoff lcone lis lused lto lmeasure________solids.
A. lsuspended
B. lcolloidal l
C. lvolatile
D. lsettleable l- l lCorrect lanswer.D. lsettleable l
(Operation lof lWastewater lTreatment lPlants, lVolume l1
by lKenneth lD. lKerri)
A l_____ lflume lis lwidely lused lfor lmeasuring lwastewater lflow. l- l lCorrect lanswer.Parshall
(Operation lof lWastewater lTreatment lPlants, lVolume l1
by lKenneth lD. lKerri)
Velocity lof lflow lin la lgrit lchannel lmust lbe lreduced lto la lrange lof l____ lto l_____ lfps lin lorder lfor lgrit lto
lproperly lsettle. l- l lCorrect lanswer..7 lto l1.4 lfps
(Operation lof lWastewater lTreatment lPlants, lVolume l1, l3.33
by lKenneth lD. lKerri)
With lrespect lto lgrit lremoval lsystems, lgrit lis ltraditionally ldefined las lparticles llarger lthan l0.21mm
l(0.008 lin) l(65 lmesh) land lwith la lspecific lgravity lof lgreater lthan l______. l- l lCorrect lanswer.specific
lgravity lof lgrit lis l2.65 lor lgreater l
,(EPA lWastewater lTechnology lFact lSheet, lScreening land lGrit lRemoval)
Mechanically lcleaned lbar lscreens lfeature lbars lset lat l_____ lto l_____ ldegrees lfrom lvertical. l- l lCorrect
lanswer.Bars lset lat l0 lto l30 ldegrees lfrom lvertical.
(EPA lWastewater lTechnology lFact lSheet, lScreening land lGrit lRemoval)
Manually lcleaned lbar lscreens lfeature lbars lset lat l_____ lto l_____ ldegrees lfrom lvertical lto lfacilitate
lcleaning. l- l lCorrect lanswer.Bars lset lat l30 lto l45 ldegrees lfrom lvertical lto lfacilitate lcleaning. lPrimarily
lused lin lolder lor lsmaller ltreatment lfacilities, lor lin lbypass lchannels.
(EPA lWastewater lTechnology lFact lSheet, lScreening land lGrit lRemoval)
The lBOD ltest lmeasures lthe lamount lof loxygen lthat lis lconsumed lwhile la lsample lof lwastewater lis
lincubated lin lthe ldark lat la ltemperature lof l_____ l°C lfor l_____ ldays l(± l_____ lhours) l- l lCorrect
lanswer.The lBOD ltest lmeasures lthe lamount lof loxygen lthat lis lconsumed lwhile l a lsample lof lwastewater
lis lincubated lin lthe ldark lat la ltemperature lof l20 l°C lfor l5 ldays l(± l3 lhours)
(USGS lBook l9-A7 l(Third lEdition) lFive-Day lBiochemical lOxygen lDemand)
What ldo lwe lmean lby lTotal lDissolved lSolids l(TDS) lin lwastewater? l- l lCorrect lanswer.All lthe lsolids lthat
lcannot lbe lfiltered lout lof lthe lwater
(New lMexico lWastewater lSystems lOperator lCertification lStudy lManual)
What ldo lwe lmean lby lTotal lSuspended lSolids l(TSS) lin lwastewater? l- l lCorrect lanswer.All lthe lsolids lthat
lcan lbe lfiltered lout lincluding: lsettleable lsolids land lnon-settleable lsolids l(colloids)
(New lMexico lWastewater lSystems lOperator lCertification lStudy lManual)
, The lwastewater lin la lsewer lline lshould lmove lat la lspeed lthat lwill lprevent lthe ldeposition land lbuildup
lof lsolids lin lthe lsewer; lthis lis lcalled la l"scouring lvelocity". lA lminimum lvelocity lof l_____ lfps lprovides
lthis lscouring lor lself-cleaning lvelocity. l- l lCorrect lanswer.The lwastewater lin la lsewer lline lshould lmove
lat la lspeed lthat lwill lprevent lthe ldeposition land lbuildup lof lsolids lin lthe lsewer; lthis lis lcalled la
l"scouring lvelocity". lA lminimum lvelocity lof l2 lfps lprovides lthis lscouring lor lself-cleaning lvelocity. l
(New lMexico lWastewater lSystems lOperator lCertification lStudy lManual)
Wastewater ltreatment lponds: lFacultative lponds lare l_____ lfeet ldeep l- l lCorrect lanswer.Facultative
lponds lare l4-8 lfeet ldeep
(New lMexico lWastewater lSystems lOperator lCertification lStudy lManual)
Wastewater ltreatment lponds: lAnaerobic lponds lare l_____ lfeet ldeep l- l lCorrect lanswer.Anaerobic
lponds lare l>14 lfeet lin ldepth
(New lMexico lWastewater lSystems lOperator lCertification lStudy lManual)
Typical lPrimary lClarifier lEfficiencies: lSettleable lSolids lexpected lremoval lefficiency l_____% lto l_____% l-
l lCorrect lanswer.Typical lPrimary lClarifier lEfficiencies: lSettleable lSolids lexpected lremoval lefficiency l95%
lto l99%
(New lMexico lWastewater lSystems lOperator lCertification lStudy lManual)
Typical lPrimary lClarifier lEfficiencies: lSuspended lSolids lexpected lremoval lefficiency l_____% lto l_____%
l- l lCorrect lanswer.Typical lPrimary lClarifier lEfficiencies: lSuspended lSolids lexpected lremoval lefficiency
l40% lto l60% l
(New lMexico lWastewater lSystems lOperator lCertification lStudy lManual)
TREATMENT PLANTS LEVELS 1-2 EXAM
PREP COMPLETE DETAILED CASE
STUDY
An lImhoff lcone lis lused lto lmeasure________solids.
A. lsuspended
B. lcolloidal l
C. lvolatile
D. lsettleable l- l lCorrect lanswer.D. lsettleable l
(Operation lof lWastewater lTreatment lPlants, lVolume l1
by lKenneth lD. lKerri)
A l_____ lflume lis lwidely lused lfor lmeasuring lwastewater lflow. l- l lCorrect lanswer.Parshall
(Operation lof lWastewater lTreatment lPlants, lVolume l1
by lKenneth lD. lKerri)
Velocity lof lflow lin la lgrit lchannel lmust lbe lreduced lto la lrange lof l____ lto l_____ lfps lin lorder lfor lgrit lto
lproperly lsettle. l- l lCorrect lanswer..7 lto l1.4 lfps
(Operation lof lWastewater lTreatment lPlants, lVolume l1, l3.33
by lKenneth lD. lKerri)
With lrespect lto lgrit lremoval lsystems, lgrit lis ltraditionally ldefined las lparticles llarger lthan l0.21mm
l(0.008 lin) l(65 lmesh) land lwith la lspecific lgravity lof lgreater lthan l______. l- l lCorrect lanswer.specific
lgravity lof lgrit lis l2.65 lor lgreater l
,(EPA lWastewater lTechnology lFact lSheet, lScreening land lGrit lRemoval)
Mechanically lcleaned lbar lscreens lfeature lbars lset lat l_____ lto l_____ ldegrees lfrom lvertical. l- l lCorrect
lanswer.Bars lset lat l0 lto l30 ldegrees lfrom lvertical.
(EPA lWastewater lTechnology lFact lSheet, lScreening land lGrit lRemoval)
Manually lcleaned lbar lscreens lfeature lbars lset lat l_____ lto l_____ ldegrees lfrom lvertical lto lfacilitate
lcleaning. l- l lCorrect lanswer.Bars lset lat l30 lto l45 ldegrees lfrom lvertical lto lfacilitate lcleaning. lPrimarily
lused lin lolder lor lsmaller ltreatment lfacilities, lor lin lbypass lchannels.
(EPA lWastewater lTechnology lFact lSheet, lScreening land lGrit lRemoval)
The lBOD ltest lmeasures lthe lamount lof loxygen lthat lis lconsumed lwhile la lsample lof lwastewater lis
lincubated lin lthe ldark lat la ltemperature lof l_____ l°C lfor l_____ ldays l(± l_____ lhours) l- l lCorrect
lanswer.The lBOD ltest lmeasures lthe lamount lof loxygen lthat lis lconsumed lwhile l a lsample lof lwastewater
lis lincubated lin lthe ldark lat la ltemperature lof l20 l°C lfor l5 ldays l(± l3 lhours)
(USGS lBook l9-A7 l(Third lEdition) lFive-Day lBiochemical lOxygen lDemand)
What ldo lwe lmean lby lTotal lDissolved lSolids l(TDS) lin lwastewater? l- l lCorrect lanswer.All lthe lsolids lthat
lcannot lbe lfiltered lout lof lthe lwater
(New lMexico lWastewater lSystems lOperator lCertification lStudy lManual)
What ldo lwe lmean lby lTotal lSuspended lSolids l(TSS) lin lwastewater? l- l lCorrect lanswer.All lthe lsolids lthat
lcan lbe lfiltered lout lincluding: lsettleable lsolids land lnon-settleable lsolids l(colloids)
(New lMexico lWastewater lSystems lOperator lCertification lStudy lManual)
, The lwastewater lin la lsewer lline lshould lmove lat la lspeed lthat lwill lprevent lthe ldeposition land lbuildup
lof lsolids lin lthe lsewer; lthis lis lcalled la l"scouring lvelocity". lA lminimum lvelocity lof l_____ lfps lprovides
lthis lscouring lor lself-cleaning lvelocity. l- l lCorrect lanswer.The lwastewater lin la lsewer lline lshould lmove
lat la lspeed lthat lwill lprevent lthe ldeposition land lbuildup lof lsolids lin lthe lsewer; lthis lis lcalled la
l"scouring lvelocity". lA lminimum lvelocity lof l2 lfps lprovides lthis lscouring lor lself-cleaning lvelocity. l
(New lMexico lWastewater lSystems lOperator lCertification lStudy lManual)
Wastewater ltreatment lponds: lFacultative lponds lare l_____ lfeet ldeep l- l lCorrect lanswer.Facultative
lponds lare l4-8 lfeet ldeep
(New lMexico lWastewater lSystems lOperator lCertification lStudy lManual)
Wastewater ltreatment lponds: lAnaerobic lponds lare l_____ lfeet ldeep l- l lCorrect lanswer.Anaerobic
lponds lare l>14 lfeet lin ldepth
(New lMexico lWastewater lSystems lOperator lCertification lStudy lManual)
Typical lPrimary lClarifier lEfficiencies: lSettleable lSolids lexpected lremoval lefficiency l_____% lto l_____% l-
l lCorrect lanswer.Typical lPrimary lClarifier lEfficiencies: lSettleable lSolids lexpected lremoval lefficiency l95%
lto l99%
(New lMexico lWastewater lSystems lOperator lCertification lStudy lManual)
Typical lPrimary lClarifier lEfficiencies: lSuspended lSolids lexpected lremoval lefficiency l_____% lto l_____%
l- l lCorrect lanswer.Typical lPrimary lClarifier lEfficiencies: lSuspended lSolids lexpected lremoval lefficiency
l40% lto l60% l
(New lMexico lWastewater lSystems lOperator lCertification lStudy lManual)
