Tenn. Comp. R. & Regs. 0400-49-01-.08

Current through October 22, 2024

Section 0400-49-01-.08 - CLASSIFICATION OF WASTEWATER TREATMENT PLANTS AND WASTEWATER COLLECTION SYSTEMS

(1) Wastewater treatment plants shall be classified by the Board or its authorized representative into one of five groups, designated either as Biological/Natural, Grade I, II, III, or IV. These classifications shall be made in accordance with the point total scheme below which takes into account the design flow of the plant, its type of unit processes, its character, and the volume of wastewater it treats.

(2) The term "collection system" means a system for the collection and transmission of wastewater to a treatment plant.

(3) The classification of a wastewater treatment plant or a wastewater collection system may be changed by the Board or its authorized representative because of changes in the conditions or the circumstances upon which the original classification was based. Notice of such a classification change shall be given to the management officers of the plant or system.

(4) Types of Wastewater Systems:

(a) A wastewater treatment plant, except Biological/Natural, will be classified either as Grade I, II, III or IV in accordance with the following point totals:

Grade IV	............................76 or more points
Grade III	................................... 56 to 75 points
Grade II	......................................... 55 points or less
Grade I	............... This classification is for a wastewater treatment plant with a capacity of seventy-five thousand (75,000) gallons per day or less. This classification serves as a Collection System certification for Grade I Collection Systems with less than fifteen (15) service connections.
Biological/Natural	... This classification is for wastewater systems using natural biological treatment as the predominant means for treatment. This includes stabilization ponds, intermittent sand filters, recirculating sand filters, spray-irrigation, constructed wetlands, aerated lagoons, and overland flow systems. This classification serves as a Collection System certification for Grade I Collection Systems with less than fifteen (15) service connections.

Point totals for plant classification shall be computed in accordance with the following rating value criteria:

	Rating Value Points
Design Flow - For every one million (1,000,000) gallons per day design capacity, fraction thereof, a plant will be awarded rating value of: ...........	2 pts.
	(30 points maximum)

Effluent Discharge - Based upon the following factors, a plant will be awarded rating values of:

Receiving stream (sensitivity) ...................	0-7 pts.*
Land disposal evaporation ....................	2 pts.
Subsurface disposal .......................	4 pts.
Variation in Raw Wastes - Based upon the variation in the quality of the raw plant will be awarded a rating value of: ..................	wastes, 0-6 pts.*

Preliminary Treatment Units - A plant employing any of the following preliminary treatment processes will be awarded rating values of:

Manually cleaned screens .....................	2 pts
Mechanically cleaned screens ....................	3 pts
Preaeration ..............................	2 pts
Comminutor, barminutor, grinders, etc .................	3 pts
Grit removal ............................	3 pts
Raw sewage pumping ........................	3 pts
Flow equalization basins (Aerated) .................	5 pts
Flow equalization basins (Unaerated) ...................	2 pts
Fine screens ............................	3 pts

Primary Treatment Units - A plant employing any of the following primary treatment processes will be awarded rating values of:

Pre-chlorination ...........................	3 pts
Primary Clarifiers .........................	5 pts
Primary Clarifiers with chemical settling aid ...............	7 pts
Swirl system ...........................	3 pts

Secondary Treatment Units - A plant employing any of the following secondary treatment processes will be awarded rating values of:

Secondary Clarifiers ..........................	5 pts
Flocculation with or without chemical aid .................	7 pts
Trickling Filter without recirculation .................	6 pts
Trickling Filter with recirculation ....................	8 pts
Activated Sludge+
Oxidation ditch .........................	8 pts
Mechanical aeration ......................	9 pts
Diffused or dispersed aeration ................	10 pts
Batch Treatment (ICEAS, etc .................	10 pts
Pure oxygen ...........................	15 pts

+ Add ten (10) additional points for a two-stage activated sludge facility

Tertiary Treatment Units/Advanced Treatment - A plant employing any of the following tertiary, or advanced, treatment processes will be awarded rating values of:

Polishing pond or Effluent flow equalization ................	2 pts
Land application of treated effluent ...................	5 pts
Chemical treatment removal .....................	6 pts
Denitrification ..........................	10 pts
Sand or mixed media filters .......................	8 pts
Activated Carbon Beds ......................	10 pts
Nitrification required by permit
By Activated Sludge .....................	6 pts
Nitrification by other process ..................	5 pts

Disinfection - Based upon the type of disinfection process employed, a plant will be awarded rating values of:

Chlorination .............................	5 pts
Dechlorination ............................	5 pts
Ozonization .............................	10 pts
Ultraviolet ..............................	5 pts

Sludge Treatment and Handling - A plant employing any of the following sludge treatment and handling facilities will be awarded rating values of:

Anaerobic digestion
Unheated ............................	5 pts
Heated ...........................	10 pts
Aerobic digestion .........................	7 pts
Drying beds .............................	3 pts
Sand bed with polymer added ....................	5 pts
Gravity thickener .........................	5 pts
Dissolved air floatation thickener ..................	8 pts
Vacuum filter ............................	8 pts
Centrifuge .............................	8 pts
Belt Press, Plate & Frame .....................	8 pts
Solids reduction (Incinerator, wet oxidation, etc.) ............	15 pts
Land application ..........................	5 pts
Chemical stabilization with lime .....................	8 pts
All other dewatering units including wedgewire and vacuum beds, both with polymers ..........................	5 pts
Composting: Invessel .......................	10 pts
Composting: Static Pile ......................	5 pts
Sludge Lagoon ..........................	3 pts

Laboratory Control by Plant Personnel - Based upon the type and difficulty of laboratory work performed at a plant, a plant will be awarded rating values of:

Bacteriological (Complexity) .....................	0-10 pts.*
Chemical/Physical (Complexity) ...................	0-10 pts.*
	Total Points **

* See Table 2

** If a rating value points total would not accurately reflect special conditions at a plant and a material distortion in its rating would occur, the Board will establish the classification of the plant after a review of its special conditions.

Table 2

Effluent Discharge - Points are assigned to a plant based upon the following receiving stream sensitivity criteria .........................

0-7 pts.*

The key concept is the degree of dilution provided under low flow conditions. Assigned point values are:

Secondary, or equivalent to secondary, wastewater treatment only is required ......	1 pt.
Advanced secondary treatment ....................	3 pts.
Tertiary treatment ..........................	5 pts.
Effluent used in a direct reuse system ................	7 pts.
Variation in Raw Wastes - Points are assigned to a plant based upon the variation from slight to extreme of the following factors: .................	0-6 pts.*

The key concept is frequency and/or intensity of deviation or excessive variation from normal or typical fluctuations; such deviation can be in terms of strength, toxicity, shock.

Recurring deviations or excessive variations in strength and/or flow less than 100 percent ...............................	0 pts.
Recurring deviations or excessive variations in strength and/or flow from 100 to 200 percent .............................	2 pts.
Recurring deviations or excessive variations in strength and/or flow of more than 4 200 percent .............................	pts.
Raw wastes subject to toxic waste discharges .............	6 pts.

Laboratory Control by Plant Personnel - Points are assigned in accordance with the type of laboratory control performed at the plant:

Bacteriological/biological (complexity) ..............

0-10 pts.*

The key concept is to credit bacteriological/biological lab work done on-site by plant personnel. Assigned point values are:

Lab work done outside the plant .....................	0 pts
Membrane filter procedures ...............	3 pts
Use of fermentation tubes or any dilution method .....	5 pts
Biological identification .................	7 pts

Chemical/physical (complexity) ..................

0-10 pts.*

The key concept is to credit chemical/physical lab work done on-site by plant personnel.

Lab work done outside the plant ...............	0 pts.
Push-button or visual methods for simple tests such as pH, settleable solids .......................	3 pts.
Additional procedures such as DO, COD, BOD, gas analysis, titrations, solids, volatile content ..............	5 pts.
More advanced determinations such as specific nutrients, total oils, phenols, etc .......................	7 pts.
Highly sophisticated instrumentation such as atomic absorption and gas chromatography ................. 1	0 pts.

These terms describe the minimum level of effluent quality attainable for treated wastewater under standard design conditions in terms of the arithmetic mean of the values for effluent samples collected in a period of thirty (30) consecutive days for the following parameters: five-day biochemical oxygen demand (BOD5); total suspended solids (TSS); and acidity/alkalinity (pH).

1. "Equivalent to secondary wastewater treatment" means the 30-day average for BOD5 does not exceed 45 mg/l and there is no ammonia limit.

2. "Secondary wastewater treatment" means the 30-day average for BOD5 does not exceed 30 mg/l and there is no ammonia limit.

3. "Advanced secondary wastewater treatment" means that the biochemical oxygen demand is expressed as the carbonaceous form (CBOD₅) that is equal to or greater than 10 mg/l and is equal to or less than 25 mg/l; and there is an ammonia limit.

4. "Tertiary wastewater treatment" means that the CBOD₅ is less than 10 mg/l and there is an ammonia limit.

(b) Grade I Collection System. This classification is for a wastewater collection system that uses collector and/or transmission lines to transport wastewater to a treatment plant and which serves no more than five thousand (5,000) service connections.

(c) Grade II Collection System. This classification is for a wastewater collection system that uses collector and/or transmission lines to transport wastewater to a treatment plant and which serves more than five thousand (5,000) service connections.

Tenn. Comp. R. & Regs. 0400-49-01-.08

Original rule filed May 21, 2014; effective August 19, 2014. Rule renumbered from 1200-05-03.

Authority: T.C.A. §§ 4-5-201, et seq. and 68-221-901, et seq.