| Size (Peak day design capacity, gallons per day) | less than 10,000 | 1 |
| Size (Peak day design capacity, gallons per day) | 10,000 - 50,000 | 2 |
| Size (Peak day design capacity, gallons per day) | 50,001 - 100,000 | 4 |
| Size (Peak day design capacity, gallons per day) | 100,001 - 500,000 | 9 |
| Size (Peak day design capacity, gallons per day) | 500,001 - 1,000,000 | 12 |
| Size (Peak day design capacity, gallons per day) | 1,000,001 - 5,000,000 | 16 |
| Size (Peak day design capacity, gallons per day) | 5,000,001 - 10,000,000 | 20 |
| Size (Peak day design capacity, gallons per day) | 10,000,001 - 50,000,000 | 25 |
| Size (Peak day design capacity, gallons per day) | greater than 50,000,000 | 30 |
| Pretreatment | Influent pumping | 2 |
| Pretreatment | Flow equalization basin | 1 |
| Pretreatment | Manually cleaned screens | 1 |
| Pretreatment | Mechanically cleaned screens | 2 |
| Pretreatment | Fine screens, including microscreens | 3 |
| Pretreatment | Comminutor, barminutor, grinders | 2 |
| Pretreatment | Grit removal | 2 |
| Primary Treatment | Primary clarifiers | 4 |
| Primary Treatment | Primary clarifiers with chemical addition | 7 |
| Primary Treatment | Imhoff tank, or other method of combined sedimentation and digestion, other than a septic tank | 3 |
| Primary Treatment | Dissolved air flotation | 16 |
| Secondary Treatment | Trickling filter without recirculation | 5 |
| Secondary Treatment | Trickling filter with recirculation | 8 |
| Secondary Treatment | Activated sludge: Oxidation ditch | 8 |
| Secondary Treatment | Activated sludge: Diffused or dispersed aeration | 10 |
| Secondary Treatment | Activated sludge: Pure oxygen | 15 |
| Secondary Treatment | Activated sludge: Sequencing batch reactor (SBR), intermittent cycle extended aeration system (ICEAS), or other batch treatment method | 20 |
| Secondary Treatment | Activated sludge: Additional points if an activated sludge plant is operated in high rate mode or contact stabilization mode | 2 |
| Secondary Treatment | Rotating biological contactor | 10 |
| Secondary Treatment | Activated bio-filter with aeration | 10 |
| Secondary Treatment | Activated bio-filter without aeration | 8 |
| Secondary Treatment | Stabilization ponds without aeration | 5 |
| Secondary Treatment | Aerated lagoon | 8 |
| Secondary Treatment | Secondary clarifiers | 4 |
| Secondary Treatment | Secondary clarifiers with chemical addition | 7 |
| Advanced Waste Treatment | Polishing pond or effluent flow equalization | 2 |
| Advanced Waste Treatment | Chemical and physical treatment without secondary treatment | 20 |
| Advanced Waste Treatment | Chemical and physical treatment following secondary treatment | 15 |
| Advanced Waste Treatment | Ion exchange | 4 |
| Advanced Waste Treatment | Granular media filtration | 8 |
| Advanced Waste Treatment | Membrane filtration | 8 |
| Advanced Waste Treatment | Membrane filtration, integrated system | 12 |
| Advanced Waste Treatment | Electrodyalysis, electrodialysis reversal | 20 |
| Advanced Waste Treatment | Biological or combined chemical and biological nutrient removal | 12 |
| Advanced Waste Treatment | Nitrification by extended aeration only | 2 |
| Advanced Waste Treatment | Chemical precipitation of phosphorous | 3 |
| Advanced Waste Treatment | pH adjustment | 3 |
| Advanced Waste Treatment | Activated carbon columns or beds | 8 |
| In-plant Odor Control | Biofilter | 3 |
| In-plant Odor Control | Adsorption with activated carbon or equal adsorbent | 3 |
| In-plant Odor Control | Wet scrubber | 3 |
| In-plant Odor Control | Thermal deactivation with catalytic process | 6 |
| In-plant Odor Control | Odor-reducing sprays | 2 |
| Sludge Thickening and Dewatering | Sludge decant tank | 2 |
| Sludge Thickening and Dewatering | Gravity thickener basin | 3 |
| Sludge Thickening and Dewatering | Gravity belt thickener | 4 |
| Sludge Thickening and Dewatering | Screw press | 5 |
| Sludge Thickening and Dewatering | Centrifuge | 6 |
| Sludge Thickening and Dewatering | Belt filter press, plate-and-frame press, or vacuum filter | 8 |
| Sludge Thickening and Dewatering | Sludge bagger | 3 |
| Sludge Thickening and Dewatering | Evaporative sludge drying by means of drying beds | 2 |
| Sludge Thickening and Dewatering | Additional points if a polymer is added to sludge before the sludge is put in drying beds | 3 |
| Sludge Stabilization and Conditioning | Unheated anaerobic digestion | 8 |
| Sludge Stabilization and Conditioning | Heated anaerobic digestion | 10 |
| Sludge Stabilization and Conditioning | Aerobic digestion | 5 |
| Sludge Stabilization and Conditioning | Wet oxidation | 10 |
| Sludge Stabilization and Conditioning | Chemical stabilization with lime | 3 |
| Sludge Stabilization and Conditioning | In-vessel composting, if controlled and operated by the operator as part of routine system operations | 10 |
| Sludge Stabilization and Conditioning | Static pile composting, if controlled and operated by the operator as part of routine system operations | 5 |
| Solids Disposal | Incineration, if controlled and operated by the operator as part of routine system operations | 12 |
| Solids Disposal | Land application, if controlled and operated by the operator as part of routine system operations | 5 |
| Solids Disposal | Sludge lagoon | 3 |
| Solids Disposal | Off-site disposal | 1 |
| Disinfection | Liquid and powdered hypochlorites | 3 |
| Disinfection | Additional points if hypochlorites are generated on-site | 2 |
| Disinfection | Gas chlorine | 12 |
| Disinfection | Chlor-Alkali on-site generation | 12 |
| Disinfection | Chlorination using tablets | 1 |
| Disinfection | Ultraviolet light | 3 |
| Disinfection | Ozonation without pure oxygen | 3 |
| Disinfection | Ozonation with pure liquefied oxygen | 4 |
| Disinfection | Ozonation with on-site generation of pure oxygen | 5 |
| Disinfection | Dechlorination with gas | 10 |
| Disinfection | Dechlorination with dechlorination agents other than gas | 3 |
| Disinfection | Dechlorination using tablets | 1 |
| Effluent Discharge | Plant pumping of effluent | 2 |
| Effluent Discharge | Effluent aeration | 2 |
| Other Treatment | Other wastewater treatment | 0 |
