Commercial Septic System Installer Exam
Questions with Correct Answers 2025
AllBtanksBmustBhave:B-BCORRECTBANSWERB-2Bcompartments
AllBtanksBwhetherBpre-
manufacturedBorBconstructedBonBsiteBshallBbeBconstructedBsoBthatBtheBlengthBisB___________Bco
mparedBtoBtheBwidth.B-BCORRECTBANSWERB-atBleastBoneBandBone-
BhalfB(1B1/2)Btimes...B"toBtheBwidth."
SepticBTanksBmayBbeBmadeBof:B-BCORRECTBANSWERB-
Concrete,BPlastic,Bfiberglass,BorBotherBmaterialsBasBapprovedBbyBtheBdepartment.
TankBcompartmentBpartitionsBwillBbeBlocated:B-BCORRECTBANSWERB-NotBlessBthanBtwo-
thirdsBorBmoreBthanBthree-fourthsBtheBLengthBofBtheBtankBfromBtheBInletBend.
CompartmentBpartitionsBwillBbeBconstructedBsoBaBpass-
thruBholeBorBslotBequalBtoBorBgreaterBthanBtheBdiameterBofBtheBinletBpipeBisBpositionedBbelowBtheBl
iquidBsurfaceBwithBaB_____________________________.B-BCORRECTBANSWERB-
MinimumB25%BtoBaBmaximumBofB50%BofBtheBtotalBliquidBdepth.
TotalBliquidBdepthBforBlargerBpoured-in-
placeBtanksBshallBhaveBaBmaximumBofB______________inchesB-BCORRECTBANSWERB-66Binches
TrueBorBFalse:BWallsBandBbottomBofBpoured-in-placeBsepticBtanksBmustBbeBreinforced.B-
BCORRECTBANSWERB-True
HowBcanBaBSepticBtankBbeBreinforced?B-BCORRECTBANSWERB-
sixBinchBbyB6BinchB(6"x6")BNo.10BgageBweldedBsteelBreinforcingBwireBORBfibrousBreinforcingBmateri
alBconformingBtoBASTMBspecificationsBforBsuchBmaterials.
, HowBmustBTankBLidsBbeBReinforced?B-BCORRECTBANSWERB-usingBthree-
eightsBsteelBreinforcingBrodsB(rebar)BwhichBshallBbeBspacedBtwelveBinchesB(12")BonBcenterBeachBwa
yBextendingBaBminimumBofBtwoBandBoneBhalfB(2B1/2")BinchesBandBaBmaximumBofBthreeB(3")BfromBt
heBoutsideBedgeBofBtheBtankBlid.
InBgeneral,BtheBtankBmustBbeBableBtoBwithstandBaBuniformBliveBloadBofB______________________B
poundsBperBsquareBfootBinBadditionBtoBallBloadsBtoBwhichBanBundergroundBtankBisBnormallyBsubjec
ted.B-BCORRECTBANSWERB-150
TrueBorBFalse:BWalls,Bbottoms,BandBlidsBofBpoured-in-
placeBsepticBtanksBshouldBhaveBaBminimumBthicknessBofBfourBinchesB(4").B-BCORRECTBANSWERB-
True
TankBlidsBshallBbeBconstructedBinB______________________BpiecesBandBshallBhaveBsecurable,Bre
movableBaccessBopeningsBlocatedBsoBthatBtheBinletBandBoutletBteesBcanBbeB__________________
______________.B-BCORRECTBANSWERB-oneBorBtwo,B
readilyBaccessed.
AccessBopeningBshallBhaveBaBminimumBofB_________________BandBmaximumBofB_____________
______BfreeBspace.B-BCORRECTBANSWERB-Minimum:B15"
Maximum:B24"
TanksBwithBmoreBthanB12BinchesBofBcoverBmustBextendBaccessBopeningsBtoBwithinB______BinchesB
ofBtheBgroundBsurface.B-BCORRECTBANSWERB-12
AllBtanksBshallBbeBequippedBwithB________________________________BratedBorBequivalentBtees
BatBtheBinletBandBoutletBendsBofBtheBtank.B-BCORRECTBANSWERB-FourBinchB(4")BPVC,BASTMB3034
Questions with Correct Answers 2025
AllBtanksBmustBhave:B-BCORRECTBANSWERB-2Bcompartments
AllBtanksBwhetherBpre-
manufacturedBorBconstructedBonBsiteBshallBbeBconstructedBsoBthatBtheBlengthBisB___________Bco
mparedBtoBtheBwidth.B-BCORRECTBANSWERB-atBleastBoneBandBone-
BhalfB(1B1/2)Btimes...B"toBtheBwidth."
SepticBTanksBmayBbeBmadeBof:B-BCORRECTBANSWERB-
Concrete,BPlastic,Bfiberglass,BorBotherBmaterialsBasBapprovedBbyBtheBdepartment.
TankBcompartmentBpartitionsBwillBbeBlocated:B-BCORRECTBANSWERB-NotBlessBthanBtwo-
thirdsBorBmoreBthanBthree-fourthsBtheBLengthBofBtheBtankBfromBtheBInletBend.
CompartmentBpartitionsBwillBbeBconstructedBsoBaBpass-
thruBholeBorBslotBequalBtoBorBgreaterBthanBtheBdiameterBofBtheBinletBpipeBisBpositionedBbelowBtheBl
iquidBsurfaceBwithBaB_____________________________.B-BCORRECTBANSWERB-
MinimumB25%BtoBaBmaximumBofB50%BofBtheBtotalBliquidBdepth.
TotalBliquidBdepthBforBlargerBpoured-in-
placeBtanksBshallBhaveBaBmaximumBofB______________inchesB-BCORRECTBANSWERB-66Binches
TrueBorBFalse:BWallsBandBbottomBofBpoured-in-placeBsepticBtanksBmustBbeBreinforced.B-
BCORRECTBANSWERB-True
HowBcanBaBSepticBtankBbeBreinforced?B-BCORRECTBANSWERB-
sixBinchBbyB6BinchB(6"x6")BNo.10BgageBweldedBsteelBreinforcingBwireBORBfibrousBreinforcingBmateri
alBconformingBtoBASTMBspecificationsBforBsuchBmaterials.
, HowBmustBTankBLidsBbeBReinforced?B-BCORRECTBANSWERB-usingBthree-
eightsBsteelBreinforcingBrodsB(rebar)BwhichBshallBbeBspacedBtwelveBinchesB(12")BonBcenterBeachBwa
yBextendingBaBminimumBofBtwoBandBoneBhalfB(2B1/2")BinchesBandBaBmaximumBofBthreeB(3")BfromBt
heBoutsideBedgeBofBtheBtankBlid.
InBgeneral,BtheBtankBmustBbeBableBtoBwithstandBaBuniformBliveBloadBofB______________________B
poundsBperBsquareBfootBinBadditionBtoBallBloadsBtoBwhichBanBundergroundBtankBisBnormallyBsubjec
ted.B-BCORRECTBANSWERB-150
TrueBorBFalse:BWalls,Bbottoms,BandBlidsBofBpoured-in-
placeBsepticBtanksBshouldBhaveBaBminimumBthicknessBofBfourBinchesB(4").B-BCORRECTBANSWERB-
True
TankBlidsBshallBbeBconstructedBinB______________________BpiecesBandBshallBhaveBsecurable,Bre
movableBaccessBopeningsBlocatedBsoBthatBtheBinletBandBoutletBteesBcanBbeB__________________
______________.B-BCORRECTBANSWERB-oneBorBtwo,B
readilyBaccessed.
AccessBopeningBshallBhaveBaBminimumBofB_________________BandBmaximumBofB_____________
______BfreeBspace.B-BCORRECTBANSWERB-Minimum:B15"
Maximum:B24"
TanksBwithBmoreBthanB12BinchesBofBcoverBmustBextendBaccessBopeningsBtoBwithinB______BinchesB
ofBtheBgroundBsurface.B-BCORRECTBANSWERB-12
AllBtanksBshallBbeBequippedBwithB________________________________BratedBorBequivalentBtees
BatBtheBinletBandBoutletBendsBofBtheBtank.B-BCORRECTBANSWERB-FourBinchB(4")BPVC,BASTMB3034