15A NCAC 18E .0803      GREASE TANK CAPACITY REQUIREMENTS

(a)  Grease tanks or grease tanks used with grease traps shall be required for food preparation facilities, food processing facilities, and meat markets; churches, institutions, and places of public assembly that include a full kitchen; and other facilities expected to generate FOG levels that are higher than DSE as defined in Table III of Rule .0402(a) of this Subchapter. The grease tank shall be plumbed to receive all wastes associated with food handling, preparation, and cleanup. No toilet wastes shall be discharged to a grease tank.

(b)  The minimum grease tank liquid capacity shall be 1,000 gallons or as calculated by one of the following, whichever is greater:

(1)           five gallons per meal served per day;

(2)           equal to the required septic tank liquid capacity calculated in accordance with Rule .0801 of this Section; or

(3)           equal to the capacity as determined in accordance with the following:

GLC       =              D x GL x ST x HR/2 x LF

Where    GLC       =              grease tank liquid capacity, in gallons

D             =              number of seats in dining area

GL          =              gallons of wastewater per meal: 1.5 single‑service or 2.5 multiuse

ST           =              storage capacity factor = 2.5

HR          =              number of hours open

LF           =              loading factor: 1.25 if along an interstate highway; 1.0 if along US

Highway or recreational areas; or 0.8 if along other roads

(c)  When the required minimum grease tank capacity for a facility is less than or equal to 1,500 gallons, the grease tank may be a single tank with two compartments and a minimum 2:1 length to width ratio.

(d)  When the required minimum grease tank capacity for a facility is greater than 1,500 gallons, the grease tank shall have a minimum 4:1 length to width ratio and four compartments. This requirement can be met by two or more tanks in series. When this requirement is met by having two or more tanks in series, each tank in the series shall have a minimum liquid capacity of 1,000 gallons and a minimum 2:1 length to width ratio.

(e)  A grease rated effluent filter approved in accordance with Rule .1404 of this Subchapter shall be in the final compartment of the grease tank.

(f)  When two or more grease tanks are used in series in accordance with Paragraph (d) of this Rule, the following conditions shall be met:

(1)           an approved grease rated effluent filter shall be in the final compartment; and

(2)           the outlet of the initial tank shall consist of a sanitary tee extending down 40 to 60 percent of the liquid depth.

(g)  The grease tank liquid capacity requirements set forth in this Rule may be reduced by up to 50 percent when used in conjunction with a grease trap located inside the facility. The system shall be designed by a PE, if required by G.S. 89C, and approved by the Department when review of documentation provided by the PE and manufacturer demonstrate that the grease trap is projected to reduce FOG concentration by at least 50 percent.

(h)  Grease traps and grease tanks shall be maintained by a septage management firm permitted in accordance with G.S. 130A-291.1, and the contents disposed of in accordance with 15A NCAC 13B .0800.

History Note:        Authority G.S. 130A-335(e), (f), and (f1);

Eff. January 1, 2024.