15A NCAC 08G .0302      CLASSIFICATION OF BIOLOGICAL WATER POLLUTION CONTROL TREATMENT SYSTEMS

(a)  The following discharging systems are assigned a classification of Grade I Biological Water Pollution Control System unless the permitted flow, or operational complexity of the system requires a higher classification:

(1)           septic tank/sand filter systems;

(2)           biological lagoon systems; and

(3)           constructed wetlands and associated appurtenances.

(b)  Systems that utilize an activated sludge or fixed growth process with a permitted flow less than or equal to 0.5 million gallons per day (mgd) are assigned the classification of Grade II Biological Water Pollution Control System.

(c)  Systems utilizing an activated sludge or fixed growth process with permitted flows of greater than 0.5 through 2.5 million gallons per day (mgd) are assigned the classification of Grade III Biological Water Pollution Control System.

(d)  Systems utilizing an activated sludge or fixed growth process with a permitted flow greater than 2.5 million gallons per day (mgd) are assigned a classification of Grade IV Biological Water Pollution Control System.

(e)  Any system receiving a classification of Grade II Biological Water Pollution Control System that is required to achieve nutrient reduction is assigned the classification of Grade III Biological Water Pollution Control System.

(f)  Any system receiving a classification of Grade III Biological Water Pollution Control System that is required to achieve nutrient reduction is assigned the classification of Grade IV Biological Water Pollution Control System.

 

History Note:        Authority G.S. 90A-37;

Eff. April 1, 1999;

Amended Eff. December 1, 2006.