GRADE 1 WATER DISTRIBUTION STUDY
QUESTIONS WITH COMPLETE
SOLUTIONS
Whichaagencyasetsalegalalimitsaonatheaconcentrationalevelsaofaharmfulacontaminantsainapot
ableawateradistributedatoacustomers?
a.aNationalaPrimaryaDrinkingaWateraRegulationsaAgency
b.aUSaEPA
c.aUSaPublicaHealthaService
d.aOccupationalaHealthaandaSafetyaAdministrationa-aans✔✔B
Theanumberaofamonthlyadistributionasystemabacteriologicalasamplesarequiredais
a.abasedaonatheawaterawithdrawalapermitalimit
b.abasedaonatheasystemasize
c.abasedaonapopulationaserved
d.adifferentaforaeachastatea-aans✔✔c
WhataisatheamaximumacontaminantalevelaforaTTHMainatheaunitedastates?a-aans✔✔.08
UnderatheaSurfaceaWateraTreatmentaRule,adisinfectionaresidualsamustabeacollectedaatathea
samealocationainatheadistributionasystemaas?
a.acoliformasamples
b.atotalatthms
c.adisinfectionabyaproducts
d.aalkalinity,aconductivity,aandapHaforacorrosionastudiesa-aans✔✔a
Ironacanacausea"redawater"aandathusacustomeracomplaintsawhenaitsaconcentrationaisaabove
aitsasecondaryamaximum acontaminantalevelaof:
a.)a0.01amg/L
b.)a0.05amg/L
c.)a0.10amg/L
d.)a0.30amg/La-aans✔✔d
TheagoalaofatheaSurfaceaDrinkingaWateraActaisaforaeacha________atoaacceptaprimaryaenforc
ementaresponsibilitya(primacy)aforatheaoperationaofatheastate'sadrinkingawateraprogram.
a.astate
b.awateratreatmentaplant
c.aoperator
d.amunicipalitya-aans✔✔a
WhataisatheaobjectiveaofatheaTotalaColiformaRule?
a.atoaprovideaCryptosporidiumaprotectionainanewafacilities
,b.atoaensureasafealevelsaofaleadaandacopper
c.atoaprotectatheapublicafromaexposureatoagiardiaalambliaaandacrypto
d.atoapromotearoutineasurveillanceaonasystemawateraqualityatoasearchaforafecalamatteraand/o
radisease-causingabacteriaa-aans✔✔d
Whichaagencyasetsastandardsaonaconcentrationalevelsaofaharmfulacontaminantsainadrinking
awater?a-aans✔✔USEPA
Explainatheadifferenceabetweenatheadifferentatiersaofaviolations.aWhichaoneaisatheamostaseri
ous?a-
aans✔✔Tiera1aisaanaacutyaMCLaviolationarequiringapublicanotificationawithina24ahrs.aTiera2an
otificationamustaoccurawithina30adays.aTiera3arequireanotificationawithina1ayear.
AapositiveaE.acoliatestamustabeareportedatoatheaprimacyahealthaagencyawithinawhataperiodaof
atime?a-aans✔✔24ahours
Howaisathearequiredanumberaofamonthlyabacteriologicalasamplesadetermined?a-
aans✔✔Populationaserved
Whataisatheaactionalevelaforaleadainafirstadrawasamplesatakenafromacustomerataps?a-
aans✔✔.015amg/L
Aawaterasystemaisadesignatedaaacommunityapublicawaterasystemaifaitaservesahowamanyaho
mes?a-aans✔✔15aoramore
Whataauthorityaprovidesaspecificawaterasamplingainstructions?a-
aans✔✔theastateaprimacyaagency
AccordingatoatheaLeadaandaCopperaRule,awhataisatheaactionalevelaforalead?a-
aans✔✔0.015amg/L
Determineatheadetentionatimeainahoursaforatheafollowingawateratreatmentasystem:aDistributi
onapipeafromawateraplantatoastorageatankaisa549afeetainalengthaanda14ainchesainadiameter.aSt
orageatankaaveragesa2,310,000agallonsaofawateraataanyagivenatime.aFlowathroughasystemai
sa6.72amgd.a-aans✔✔8.3ahours
divideadailyaflowabya24ahoursainaaadaya(280,000)
thenadividea280,000aintoatankacapacity
Ifachlorineaisabeingafedaataaarateaofa260lb/dayaforaaaflowarateaofa23cf/s,awhatashouldabeatheaa
djustmentaonatheachlorinatorawhenatheaflowarateaisadecreasedatoa16acf/saifaallaotheraparamet
ersawereatoastayatheasame?a-aans✔✔180lb/day
260/23=x/16
dividea260abya23,athenamultiplyathatabya16
, Howamanyagallonsaofasodiumahypochloriteasolutionathatacontaina12.1%aavailableachlorinea
areaneededatoadisinfectaaa1.5ftadiameterapipelineathataisa283afeetalong,aifatheadosagearequir
edaisa50amg/L?aAssumeatheasodiumahypochloriteaisa9.92alb/gallon.a-
aans✔✔1.3agallonsasodiumahypochlorite
sodiumaHCl=[(milagal)(dosage)(8.34)]/[%availaCl2/100%]
Aastorageatankahasaaa60ftaradiusaandaaveragesa25.5ftainawateradepth.aCalculateatheaaverag
eadetentionatimeainahoursaforathisastorageatank,aifaflowathroughatheatankaaveragesa2.91amgda
duringatheamonthainaquestion.a-aans✔✔17.8ahours
Aa24inapipeline,a427ftalong,awasadisinfectedawithacalciumahypochloriteatabletsawitha65%aav
ailableachlorine.aDetermineatheachlorineadosageainamg/L,aifa7lbaofacalciumahypochloriteawas
aused.aAssumeathatatheahypochloriteaisasoadilutedathataitaweighsa8.34lb/gal.a-
aans✔✔54amg/L
CaHCl(lb/day)=a[(mgd)(dosage)(8.34)(100%)]/[%availableaCl2]
Headaisameasuredain
a.aabsoluteapressure
b.agaugeapressure
c.afeet
d.afoot-poundsa-aans✔✔c
Aaplataisa
a.aaamap
b.aaacorrosionapointaonaaapipe
c.aanaorganelleafoundainasomeaprotozoans
d.aaahighlyacorrosiveasoilatypea-aans✔✔A
Atawhichatimeaofadayaisatheaageaofatheawaterastoredainatheadistributionasystematheahighest?
a.aEarlyamorning
b.aLateamorning
c.aearlyaafternoon
d.alateaeveninga-aans✔✔a
Wateramainsashouldaprimarilyabeasizedabasedaona
a.aearthquakeapotential
b.apeakadomesticaandacommercialademands
c.apeakacommercialaandaindustrialademands
d.aadequateafireaflowaataanaappropriateapressurea-aans✔✔d
Theamostadesirablearesidentialapressurearangesafroma
a.a20atoa35apsi
QUESTIONS WITH COMPLETE
SOLUTIONS
Whichaagencyasetsalegalalimitsaonatheaconcentrationalevelsaofaharmfulacontaminantsainapot
ableawateradistributedatoacustomers?
a.aNationalaPrimaryaDrinkingaWateraRegulationsaAgency
b.aUSaEPA
c.aUSaPublicaHealthaService
d.aOccupationalaHealthaandaSafetyaAdministrationa-aans✔✔B
Theanumberaofamonthlyadistributionasystemabacteriologicalasamplesarequiredais
a.abasedaonatheawaterawithdrawalapermitalimit
b.abasedaonatheasystemasize
c.abasedaonapopulationaserved
d.adifferentaforaeachastatea-aans✔✔c
WhataisatheamaximumacontaminantalevelaforaTTHMainatheaunitedastates?a-aans✔✔.08
UnderatheaSurfaceaWateraTreatmentaRule,adisinfectionaresidualsamustabeacollectedaatathea
samealocationainatheadistributionasystemaas?
a.acoliformasamples
b.atotalatthms
c.adisinfectionabyaproducts
d.aalkalinity,aconductivity,aandapHaforacorrosionastudiesa-aans✔✔a
Ironacanacausea"redawater"aandathusacustomeracomplaintsawhenaitsaconcentrationaisaabove
aitsasecondaryamaximum acontaminantalevelaof:
a.)a0.01amg/L
b.)a0.05amg/L
c.)a0.10amg/L
d.)a0.30amg/La-aans✔✔d
TheagoalaofatheaSurfaceaDrinkingaWateraActaisaforaeacha________atoaacceptaprimaryaenforc
ementaresponsibilitya(primacy)aforatheaoperationaofatheastate'sadrinkingawateraprogram.
a.astate
b.awateratreatmentaplant
c.aoperator
d.amunicipalitya-aans✔✔a
WhataisatheaobjectiveaofatheaTotalaColiformaRule?
a.atoaprovideaCryptosporidiumaprotectionainanewafacilities
,b.atoaensureasafealevelsaofaleadaandacopper
c.atoaprotectatheapublicafromaexposureatoagiardiaalambliaaandacrypto
d.atoapromotearoutineasurveillanceaonasystemawateraqualityatoasearchaforafecalamatteraand/o
radisease-causingabacteriaa-aans✔✔d
Whichaagencyasetsastandardsaonaconcentrationalevelsaofaharmfulacontaminantsainadrinking
awater?a-aans✔✔USEPA
Explainatheadifferenceabetweenatheadifferentatiersaofaviolations.aWhichaoneaisatheamostaseri
ous?a-
aans✔✔Tiera1aisaanaacutyaMCLaviolationarequiringapublicanotificationawithina24ahrs.aTiera2an
otificationamustaoccurawithina30adays.aTiera3arequireanotificationawithina1ayear.
AapositiveaE.acoliatestamustabeareportedatoatheaprimacyahealthaagencyawithinawhataperiodaof
atime?a-aans✔✔24ahours
Howaisathearequiredanumberaofamonthlyabacteriologicalasamplesadetermined?a-
aans✔✔Populationaserved
Whataisatheaactionalevelaforaleadainafirstadrawasamplesatakenafromacustomerataps?a-
aans✔✔.015amg/L
Aawaterasystemaisadesignatedaaacommunityapublicawaterasystemaifaitaservesahowamanyaho
mes?a-aans✔✔15aoramore
Whataauthorityaprovidesaspecificawaterasamplingainstructions?a-
aans✔✔theastateaprimacyaagency
AccordingatoatheaLeadaandaCopperaRule,awhataisatheaactionalevelaforalead?a-
aans✔✔0.015amg/L
Determineatheadetentionatimeainahoursaforatheafollowingawateratreatmentasystem:aDistributi
onapipeafromawateraplantatoastorageatankaisa549afeetainalengthaanda14ainchesainadiameter.aSt
orageatankaaveragesa2,310,000agallonsaofawateraataanyagivenatime.aFlowathroughasystemai
sa6.72amgd.a-aans✔✔8.3ahours
divideadailyaflowabya24ahoursainaaadaya(280,000)
thenadividea280,000aintoatankacapacity
Ifachlorineaisabeingafedaataaarateaofa260lb/dayaforaaaflowarateaofa23cf/s,awhatashouldabeatheaa
djustmentaonatheachlorinatorawhenatheaflowarateaisadecreasedatoa16acf/saifaallaotheraparamet
ersawereatoastayatheasame?a-aans✔✔180lb/day
260/23=x/16
dividea260abya23,athenamultiplyathatabya16
, Howamanyagallonsaofasodiumahypochloriteasolutionathatacontaina12.1%aavailableachlorinea
areaneededatoadisinfectaaa1.5ftadiameterapipelineathataisa283afeetalong,aifatheadosagearequir
edaisa50amg/L?aAssumeatheasodiumahypochloriteaisa9.92alb/gallon.a-
aans✔✔1.3agallonsasodiumahypochlorite
sodiumaHCl=[(milagal)(dosage)(8.34)]/[%availaCl2/100%]
Aastorageatankahasaaa60ftaradiusaandaaveragesa25.5ftainawateradepth.aCalculateatheaaverag
eadetentionatimeainahoursaforathisastorageatank,aifaflowathroughatheatankaaveragesa2.91amgda
duringatheamonthainaquestion.a-aans✔✔17.8ahours
Aa24inapipeline,a427ftalong,awasadisinfectedawithacalciumahypochloriteatabletsawitha65%aav
ailableachlorine.aDetermineatheachlorineadosageainamg/L,aifa7lbaofacalciumahypochloriteawas
aused.aAssumeathatatheahypochloriteaisasoadilutedathataitaweighsa8.34lb/gal.a-
aans✔✔54amg/L
CaHCl(lb/day)=a[(mgd)(dosage)(8.34)(100%)]/[%availableaCl2]
Headaisameasuredain
a.aabsoluteapressure
b.agaugeapressure
c.afeet
d.afoot-poundsa-aans✔✔c
Aaplataisa
a.aaamap
b.aaacorrosionapointaonaaapipe
c.aanaorganelleafoundainasomeaprotozoans
d.aaahighlyacorrosiveasoilatypea-aans✔✔A
Atawhichatimeaofadayaisatheaageaofatheawaterastoredainatheadistributionasystematheahighest?
a.aEarlyamorning
b.aLateamorning
c.aearlyaafternoon
d.alateaeveninga-aans✔✔a
Wateramainsashouldaprimarilyabeasizedabasedaona
a.aearthquakeapotential
b.apeakadomesticaandacommercialademands
c.apeakacommercialaandaindustrialademands
d.aadequateafireaflowaataanaappropriateapressurea-aans✔✔d
Theamostadesirablearesidentialapressurearangesafroma
a.a20atoa35apsi
