(a) Scope and purpose. The objective of this section is to aid in preventing the introduction and accumulation of fats, oils, and greases into the municipal wastewater system which will or tend to cause or contribute to sanitary sewer blockages and obstructions. Food service establishments and other industrial or commercial establishments generating wastewater containing fats, oils or greases are subject to this section. This section regulates such users by requiring that grease interceptors and other approved strategies be installed, implemented, and maintained in accordance with the provisions hereof.
(b) Definitions. The definitions contained in section 36-172 and the following terms, when used in this section, shall apply.
Action level means the concentration based numeric value that the grease interceptor effluent, at the device's outlet tee and prior to mixing with any other waste water from the contributing establishment's property, are expected to achieve on a consistent or stipulated basis.
Common interceptor means one or more interceptors receiving FOG laden wastewater from more than one establishment. Common interceptors may be located at shopping centers, malls, entertainment complexes, sporting arenas, hotels, multi-tenant "flex" spaces, mixed use spaces, and other sites where multiple establishments are connected to a single grease interceptor. The owner of the property on which the common grease interceptor is located shall be primarily responsible for the maintenance, upkeep, and repair of the common interceptor.
Fats, oils, and greases means organic polar compounds derived from animal and/or plant sources that contain multiple carbon chain triglyceride molecules. These substances are detectable and measurable using analytical test procedures established in 40 CFR 136, as may be amended from time to time. All are sometimes referred to herein as "grease" or "greases" or "FOG".
Food service establishments or "FSE" means those establishments primarily engaged in activities of preparing, serving, or otherwise making available for consumption foodstuffs and that use one or more of the following preparation activities: Cooking by frying (all methods), baking (all methods), grilling, sauteing, rotisserie cooking, broiling (all methods), boiling blanching, roasting, toasting, or poaching, and infrared heating, searing, barbecuing, and any other food preparation or serving activity that produces a consumable food product in or on a receptacle requiring washing to be reused.
FOG enforcement response plan means the document and written plan and procedures by which the director implements an enforcement strategy applicable to the FOG control and management program established herein. The plan applies to FOG program violations and matters of program noncompliance. Stipulated penalties for specific and programmatic infractions are addressed in the plan and set forth in the town's annual budget ordinance. The director shall make site and case specific determinations of program non-conformance in accordance with this Division 2.
Grease trap or interceptor means a device for separating waterborne greases and grease complexes from wastewater and retaining such greases and grease complexes prior to the wastewater exiting the trap and entering the sanitary sewer collection and treatment system. Grease traps also serve to collect solids that settle, generated by and from activities that subject users to this section, prior to the water exiting the trap and entering the sanitary sewer collection and treatment system. Grease traps and interceptors are sometimes referred to herein as "grease interceptors".
Minimum design capability means the design features of a grease interceptor and its ability or volume required to effectively intercept and retain greases and settled solids from grease-laden wastewaters discharged to the public sanitary sewer.
Noncooking establishments means those establishments primarily engaged in the preparation of precooked foodstuffs that do not include any form of cooking, but that may produce a consumable food product in or on a receptacle requiring washing to be reused.
On-site grease interceptor treatment (sometimes "onsite treatment") means mechanisms or procedures utilized by a user to treat grease interceptor contents on the user's site, followed by the reintroduction of such treated wastewater back into the interceptor. On-site grease interceptor treatment may only be accomplished by a user if the user or the user's contract service provider is permitted by the NC Division of Waste Management as a septage management firm or service provider.
Program acknowledgement certificate means program confirmation documentation issued by the director. The user is required to keep program acknowledgement certificate on premises and produce it upon request of Town of Cary.
Service provider means any third party not in the employment of the user that performs maintenance, repair, and other services on a user's grease interceptor at the user's directive.
User is as defined in section 36-172 for the purpose of this section. Users include property owners who provide common interceptors for one or more independent establishments, including tenants.
(c) Grease interceptor installation, maintenance, recordkeeping, and grease removal.
(1) Grease interceptors shall be installed and maintained at the user's expense, when a User operates a food service establishment. Grease interceptors may be required in noncooking or cold dairy and frozen foodstuffs establishments and other industrial or commercial establishments when the establishment generates wastewater containing fat or grease and the director determines an interceptor is necessary to prevent contribution or accumulation of grease to the sanitary sewer collection and treatment system. Upon notification by the director or designee that the user is subject to the terms of an enforcement action, as stipulated in the FOG enforcement response plan, said user shall not allow wastewater discharge concentration from subject grease interceptor to exceed an establishment action level of 200 milligrams per liter, expressed as hexane extractable material. All grease interceptors shall be of a type, design, and capacity approved by the director and shall be readily and easily accessible for maintenance and repair, including cleaning and for town inspection. All grease interceptors shall be serviced and emptied of accumulated waste content as required in order to maintain minimum design capability or effective volume of the grease interceptor, but not less often than every 60 days or as permitted in a valid program modification. Users who are required to pass wastewater through a grease interceptor shall:
a. Provide for a minimum hydraulic retention time of 24 minutes at actual peak flow between the influent and effluent baffles, with 25 percent of the total volume of the grease interceptor being allowed for any food-derived solids to settle or accumulate and floatable grease-derived materials to rise and accumulate, identified hereafter as a solids blanket and grease cap respectively.
b. Remove any accumulated grease cap and solids blanket as required, but at intervals of not longer than 60 days at the user's expense, or in accordance with a valid program modification or other director's requirements. Grease interceptors shall be kept free of inorganic solid materials, such as grit, rocks, gravel, sand, eating utensils, cigarettes, shells, towels, rags, etc., which could settle into this solids blanket and thereby reduce the effective volume of the grease interceptor.
c. If the user performs on-site grease interceptor treatment pursuant to a modification granted under subsection 36-183(g)(5) below, user shall:
1. Prior to commencement of onsite treatment obtain written approval by and from the director of all processes utilized in said onsite treatment.
2. If any pumped wastes or other materials removed from the grease interceptor are treated in any fashion on-site and reintroduced back into the grease interceptor as an activity of and after such on-site treatment, the user shall meet the criteria contained in (c)(1)c.3. below.
3. Attain and adhere to the criteria listed below:
a. After 30 minutes of settling time, not more than 3.0 ml/L of settlable solids, as measured in a one liter Imhoff cone shall be allowed, and;
b. Within and not more than 24 hours after onsite grease interceptor servicing, not more than two inches of settlable solids and/or grease shall be allowed to have accumulated therein as a result of said operations.
c. Service vehicles and equipment used in onsite grease interceptor servicing shall be registered with the utilities department, and as required by the North Carolina Division of Waste Management.
d. When servicing grease interceptors service vehicles and equipment shall have onboard, at all times, a certificate of approval for the operations and methods used, issued by the director.
e. Any tanks, tankage, or vessel(s) associated with a modification shall be empty upon arrival at the initial FSE user site for which this modification is intended to be applied.
d. Operate and maintain the grease interceptor to achieve and consistently maintain any applicable grease action level. "Consistent" shall mean any wastewater sample taken from such grease interceptor must meet the terms of numerical limit attainment described in subsection (c)(1). If a user documents that conditions exist ("space constraints") on their establishment site that limit the ability to locate a grease interceptor on the exterior of the establishment, the user may request an interior location for the interceptor. Such request shall contain the following information:
1. Location of town sewer main and easement in relation to available exterior space outside building.
2. Existing plumbing layout at or in a site.
3. A statement of understanding, signed by the user or authorized agent, acknowledging and accepting conditions director may place on permitting an identified interior location. Conditions may include requirements to use alternative mechanisms, devices, procedures, or operations relative to an interior location.
4. Such other information as may be required by the director.
e. The use of biological or other additives as a grease degradation or conditioning agent is permissible only upon prior written approval of the director. Any user using biological or other additives shall maintain the trap or interceptor in such a manner that attainment of any grease wastewater, action level, solids blanket or grease cap criteria, goal or directive, as measured from the grease interceptor outlet or interior, is consistently achieved.
f. The use of automatic grease removal systems is permissible only upon prior written approval of the director, the lead plumbing inspector of the town, and the Wake County Department of Environmental Services or the US Department of Agriculture. Any user using a grease interceptor located on the interior of the site shall be subject to any operational requirements set forth by the North Carolina Division of Waste Management. Any user using this equipment shall operate the system in such a manner that attainment of the grease wastewater discharge limit, as measured from the unit's outlet, is consistently achieved as required by the director.
g. The director may make determinations of grease interceptor adequacy need, design, appropriateness, application, location, modification(s), and conditional usage based on review of all relevant information regarding grease interceptor performance, facility site and building plan review by all regulatory reviewing agencies and may require repairs to, or modification or replacement of grease interceptors.
(2) The user shall maintain a written record of grease interceptor maintenance for three years. All such records will be available for inspection by the town at all times. These records shall include:
a. FSE name and physical location;
b. Date of grease interceptor service;
c. Time of grease interceptor service;
d. Name of grease interceptor service company;
e. Name and signature of grease interceptor service company agent performing said service;
f. Established service frequency and type of service: full pumpout, partial pumpout, on-site treatment (type of nature of operations);
g. Number and size of each grease interceptor serviced at FSE location;
h. Approximated amount, per best professional judgement of contract service provider, of grease and solids removed from each grease interceptor;
i. Total volume of waste removed from each grease interceptor;
j. Destination of removed wastes, food solids, and wastewater disposal;
k. Signature and date of FSE personnel confirming service completion;
l. Such other information as required by director.
(3) No nongrease-laden sources are allowed to be connected to sewer lines intended for grease interceptor service.
(4) Access manholes shall have an installed diameter of 24 inches, a maximum weight of 50 pounds, and shall be provided over each chamber, interior baffle wall, and each sanitary tee. The access penetrations, commonly referred to as "risers" into the grease interceptor shall also be, at a minimum, 24 inches in diameter. The access manholes shall extend at least to finished grade and be designed and maintained to prevent water inflow or infiltration. The manholes shall also have readily removable covers to facilitate inspection, grease removal, and wastewater sampling activities.
(5) A user may request a modification to the following requirements of this section. Such request for a modification shall be in writing and shall provide the information set forth below.
a. The user's grease interceptor pumping frequency. The director may modify the 60-day grease interceptor pump out frequency when the user provides data, and performance criteria relative to the overall effectiveness of a proposed alternate and such can be substantiated by the director. Proposed alternatives may include: Grease interceptor pumping or maintenance matters, bioremediation as a complement to grease interceptor maintenance, grease interceptor selection and sizing criteria, onsite grease interceptor maintenance, and specialized ware washing procedures.
b. Grease interceptor maintenance and service procedures. The director may modify the method(s) or procedure(s) utilized service a grease interceptor when the user provides data, and performance criteria relative to the overall effectiveness of a proposed alternate method or procedure and such can be substantiated by the director. If a modification to maintenance and service procedures is permitted it shall be a conditional discharged permit approval.
c. Any modification must be approved by the director in written form before implementation by the user or the user's designated service provider. The user shall pay modification fees as set forth in the budget ordinance fee schedule.
(Code 1982, § 19-104; Ord. No. 98-021, 12-10-1998; Ord. No. 06-014, 8-10-2006; Ord. No. 2011-Code-09, 12-15-2011; Ord. No. 2019-Code-04, 10-10-2019)