Grade IV | 61 or more points |
Grade III | 35 to 60 points |
Grade II | 16 to 34 points |
Grade I | 15 or less points |
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 gallons per day design capacity, or fraction thereof, a plant will be awarded a rating value of:............. | 1 pt. |
Water Supply Source - Based upon the type and quality of the raw water source, a plant will be awarded rating values of:
Groundwater....................... | 3 pts. |
Ground water under the direct influence of surface water.... | 5 pts. |
Surface water....................... | 5 pts. |
Average raw water quality................... | 0-10 pts.* |
Treatment Process - A plant employing any of the following treatment processes will be awarded rating values of:
Aeration ............................ | 4 pts |
Presettling ........................ | 2 pts |
Flash mix .......................... | 2 pts |
Coagulation........................ | 6 pts |
Flocculation ......................... | 5 pts |
Settling .......................... | 5 pts |
Upflow Solids Contact ...................... | 8 pts |
Lime softening ........................ | 5 pts |
Gravity Filtration | |
slow sand ....................... | 2 pts |
rapid ....................... | 6 pts |
Pressure Filtration ...................... | 3 pts |
Recarbonation ....................... | 3 pts |
Membrane Filtration ...................... | 20 pts |
Activated alumina ...................... | 10 pts |
Ion Exchange ....................... | 5 pts |
Chemical Treatment - A plant utilizing any of the following chemicals or chemical treatment processes will be awarded rating values of:
Fluoridation ......................... | 3 pts. |
Disinfection | |
Gaseous chlorine ................... | 5 pts |
Liquid or powdered chlorine ............. | 3 pts |
Chlorine dioxide .................. | 7 pts |
Ozonization (on-site generation) ............. | 10 pts |
On-site generation of Chlorine ............ | 5 pts |
Mixed Oxidants .................... | 7 pts |
UV Light ....................... | 3 pts |
Taste and Odor Control | |
Peroxide ...................... | 3 pts |
Potassium Permanganate ............... | 2 pts |
Powdered activated carbon ............. | 4 pts |
Activated carbon columns .............. | 6 pts |
Activated carbon slurry ............... | 8 pts |
Chemical Stabilization | |
(polyphosphate, Soda Ash, etc.) ........... | 4 pts |
Laboratory Control by Plant Personnel - Based upon the type and the difficulty of the laboratory work performed at a plant, a plant will be awarded rating values of:
Bacteriological ................... | .... 0-10 pts.* |
Chemical ..................... | ... 0-10 pts.* |
Total Points ** |
* See Table 1
** 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 1
*Average Raw Water Quality - Points are assigned to a plant as follows:
Raw water quality varies enough to require treatment process changes less than thirty-six (36) days each calendar year .................. | 2 pts. |
Raw water quality varies enough to require treatment process changes thirty-six (36) days or more each calendar year ................ | 5 pts. |
Raw water quality varies enough to require treatment process changes due to existing industrial waste pollution sources ............... | 10 pts. |
*Laboratory Control by Plant Personnel (Bacteriological) - Points are assigned in accordance with the type of laboratory control performed at the plant:
Lab work done outside of plant ................... | 0 pts |
Enzyme Substrate Method ..................... | 4 pts |
Membrane filter procedure ..................... | 5 pts |
Fermentation tubes or any dilution method .............. | 7 pts |
Biological identification ........................ | 10 pts |
*Laboratory Control by Plant Personnel (Chemical) - Points are assigned in accordance with the type of laboratory control performed at the plant:
Lab work done outside the plant ................. | 0 pts |
Colorimetric methods for simple tests such as chlorine, pH ..... | 3 pts |
Procedures such as titration, jar tests ............... | 5 pts |
More advanced determinations including inorganics ........ | 7 pts |
Highly sophisticated instrumentation such as atomic absorption and gas chromatography ...................... | 10 pts |
This classification serves as a distribution system certification for those systems meeting the definition of a small water system.
Tenn. Comp. R. & Regs. 0400-49-01-.06
Authority: T.C.A. §§ 4-5-201, et seq. and 68-221-901, et seq.