Alaska Certified Water/Wastewater Operator Database
Wastewater Treatment Scoring Components

The current wastewater treatment scoring components are shown below. You may also return to the previous page.

Size (Peak day design capacity, gallons per day)less than 10,0001
Size (Peak day design capacity, gallons per day)10,000 - 50,0002
Size (Peak day design capacity, gallons per day)50,001 - 100,0004
Size (Peak day design capacity, gallons per day)100,001 - 500,0009
Size (Peak day design capacity, gallons per day)500,001 - 1,000,00012
Size (Peak day design capacity, gallons per day)1,000,001 - 5,000,00016
Size (Peak day design capacity, gallons per day)5,000,001 - 10,000,00020
Size (Peak day design capacity, gallons per day)10,000,001 - 50,000,00025
Size (Peak day design capacity, gallons per day)greater than 50,000,00030
PretreatmentInfluent pumping2
PretreatmentFlow equalization basin1
PretreatmentManually cleaned screens1
PretreatmentMechanically cleaned screens2
PretreatmentFine screens, including microscreens3
PretreatmentComminutor, barminutor, grinders2
PretreatmentGrit removal2
Primary TreatmentPrimary clarifiers4
Primary TreatmentPrimary clarifiers with chemical addition7
Primary TreatmentImhoff tank, or other method of combined sedimentation and digestion, other than a septic tank3
Primary TreatmentDissolved air flotation16
Secondary TreatmentTrickling filter without recirculation5
Secondary TreatmentTrickling filter with recirculation8
Secondary TreatmentActivated sludge: Oxidation ditch8
Secondary TreatmentActivated sludge: Diffused or dispersed aeration10
Secondary TreatmentActivated sludge: Pure oxygen15
Secondary TreatmentActivated sludge: Sequencing batch reactor (SBR), intermittent cycle extended aeration system (ICEAS), or other batch treatment method 20
Secondary TreatmentActivated sludge: Additional points if an activated sludge plant is operated in high rate mode or contact stabilization mode2
Secondary TreatmentRotating biological contactor10
Secondary TreatmentActivated bio-filter with aeration10
Secondary TreatmentActivated bio-filter without aeration8
Secondary TreatmentStabilization ponds without aeration5
Secondary TreatmentAerated lagoon8
Secondary TreatmentSecondary clarifiers4
Secondary TreatmentSecondary clarifiers with chemical addition7
Advanced Waste TreatmentPolishing pond or effluent flow equalization2
Advanced Waste TreatmentChemical and physical treatment without secondary treatment20
Advanced Waste TreatmentChemical and physical treatment following secondary treatment15
Advanced Waste TreatmentIon exchange4
Advanced Waste TreatmentGranular media filtration8
Advanced Waste TreatmentMembrane filtration8
Advanced Waste TreatmentMembrane filtration, integrated system12
Advanced Waste TreatmentElectrodyalysis, electrodialysis reversal20
Advanced Waste TreatmentBiological or combined chemical and biological nutrient removal12
Advanced Waste TreatmentNitrification by extended aeration only2
Advanced Waste TreatmentChemical precipitation of phosphorous3
Advanced Waste TreatmentpH adjustment3
Advanced Waste TreatmentActivated carbon columns or beds8
In-plant Odor ControlBiofilter3
In-plant Odor ControlAdsorption with activated carbon or equal adsorbent3
In-plant Odor ControlWet scrubber3
In-plant Odor ControlThermal deactivation with catalytic process6
In-plant Odor ControlOdor-reducing sprays2
Sludge Thickening and DewateringSludge decant tank2
Sludge Thickening and DewateringGravity thickener basin3
Sludge Thickening and DewateringGravity belt thickener4
Sludge Thickening and DewateringScrew press5
Sludge Thickening and DewateringCentrifuge6
Sludge Thickening and DewateringBelt filter press, plate-and-frame press, or vacuum filter8
Sludge Thickening and DewateringSludge bagger3
Sludge Thickening and DewateringEvaporative sludge drying by means of drying beds2
Sludge Thickening and DewateringAdditional points if a polymer is added to sludge before the sludge is put in drying beds3
Sludge Stabilization and ConditioningUnheated anaerobic digestion8
Sludge Stabilization and ConditioningHeated anaerobic digestion10
Sludge Stabilization and ConditioningAerobic digestion5
Sludge Stabilization and ConditioningWet oxidation10
Sludge Stabilization and ConditioningChemical stabilization with lime3
Sludge Stabilization and ConditioningIn-vessel composting, if controlled and operated by the operator as part of routine system operations10
Sludge Stabilization and ConditioningStatic pile composting, if controlled and operated by the operator as part of routine system operations5
Solids DisposalIncineration, if controlled and operated by the operator as part of routine system operations12
Solids DisposalLand application, if controlled and operated by the operator as part of routine system operations 5
Solids DisposalSludge lagoon3
Solids DisposalOff-site disposal1
DisinfectionLiquid and powdered hypochlorites3
DisinfectionAdditional points if hypochlorites are generated on-site2
DisinfectionGas chlorine12
DisinfectionChlor-Alkali on-site generation12
DisinfectionChlorination using tablets1
DisinfectionUltraviolet light3
DisinfectionOzonation without pure oxygen3
DisinfectionOzonation with pure liquefied oxygen4
DisinfectionOzonation with on-site generation of pure oxygen5
DisinfectionDechlorination with gas10
DisinfectionDechlorination with dechlorination agents other than gas3
DisinfectionDechlorination using tablets1
Effluent DischargePlant pumping of effluent2
Effluent DischargeEffluent aeration2
Other TreatmentOther wastewater treatment0
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