Classification points for wastewater treatment plants shall be assigned in accordance with Table 304.3:
Table 304.3 Point System for the Classification of Wastewater Treatment Plants
Item | Points |
Size | |
For industrial plants only, maximum population equivalent (pop.eq.) served, peak day | 1 per 10,000 pop.eq. or part thereof |
For all other plants, the larger of design flow (avg. day) or peak month's flow (avg. day) in gallons per day (GPD) | 0.1 per 100,000 GPD |
Effluent Discharge | |
Receiving stream sensitivity. Primary consideration is the degree of dilution provided under low flow conditions. Point values are: | 1-6 |
"Effluent limited segment" in EPA terminology; secondary treatment is adequate | 1 |
More than secondary treatment is required | 2 |
"Water quality limited segment" in EPA terminology; stream conditions are very critical (dry run, for example) and a very high degree of treatment is required | 3 |
Effluent used in direct recycle and reuse system | 6 |
Land disposal - evaporation | 2 |
Subsurface disposal | 5 |
Rapid infiltration basins | 6 |
Variation in Raw Wastes (slight to extreme), including industrial discharge connections. Primary consideration is frequency or intensity of deviation or excessive variation from normal or typical fluctuations; such deviation can be in terms of strength, toxicity, shock loads, I/I, etc. Point values are: | 0-6 |
Variations do not exceed those normally or typically expected | 0 |
Recurring deviations or excessive variations of 100 to 200 percent in strength and/or flow | 2 |
Recurring deviations or excessive variations of more than 200 percent in strength and/or flow | 4 |
Raw wastes subject to toxic waste discharges | 6 |
Pretreatment | |
Screening, comminution | 3 |
Grit removal | 3 |
Influent flow equalization | 1 |
Plant pumping of main flow | 3 |
Primary Treatment | |
Primary clarifiers | 5 |
Combined sedimentation/digestion | 5 |
Chemically enhanced primary treatment | 7 |
Secondary Treatment | |
Activated sludge with secondary clarifiers (including extended aeration, sequencing batch reactors & oxidation ditches) | 15 |
Stabilization ponds without aeration | 5 |
Aerated lagoon | 8 |
Sand filters | 5 |
Fixed film media system | 10 |
Subsurface disposal | 5 |
Rapid infiltration basins | 6 |
Overland flow | 6 |
Advanced Treatment | |
Polishing pond | 2 |
Chemical/physical, including ballasted treatment | 12 |
Biological or chemical/biological | 12 |
Ion exchange | 10 |
erse osmosis or membrane filtration | 15 |
Chemical recovery, carbon regeneration | 4 |
Spray irrigation | 8 |
Overland flow | 6 |
Filtration | 8 |
Solids Handling | |
Mechanical thickening | 5 |
Anaerobic digestion | 10 |
Aerobic digestion | 6 |
Evaporative sludge drying | 2 |
Mechanical dewatering | 8 |
Solids reduction (incineration, wet oxidation) | 12 |
Composting | 7 |
Lime stabilization | 5 |
Septage receiving | 1 |
Disinfection | |
Chlorination or comparable | 5 |
On-site generation of disinfectant | 5 |
Dechlorination | 5 |
Ultraviolet | 5 |
Effluent post aeration | 2 |
Effluent flow equalization | 1 |
Odor Control. Primary consideration is complexity of odor control system operation and maintenance. Point values are: | 0-2 |
Soil or carbon filters or equivalent | 1 |
Chemical/wet scrubber systems or equivalent | 2 |
SCADA System | 1 |
Laboratory Control by Plant Personnel. Primary consideration is complexity of lab work done by plant personnel. Point values are: | 0-10 |
Push button or visual methods for simple tests such as pH, chlorine residual, settleable solids | 1 |
Standard procedures such as DO, COD, BOD, TSS, gas analysis, filtrations, solids, volatile content, nutrients, bacteriological analysis (membrane filter, MPN, E. coli, fecal coliform, Enterococci) | 3 |
More advanced determinations, such as total oils, phenols, metals | 5 |
Biological identification | 7 |
Virus studies or similarly complex work conducted on site | 10 |
Highly sophisticated instrumentation such as atomic absorption and gas chromatography | 10 |
N.H. Admin. Code § Env-Wq 304.28
(See Revision Note at part heading for Env-Wq 304) #10392, eff 8-1-13