Agenda - 11-04-2010 - 7a - Laserfiche WebLink

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22 (e) (3) Design (1) Facilities other than those noted in subsections (d)(1) and (2) of this section may require the installation of a grease and oil interceptor. The Hillsborough town engineer of his designee shall determine the need and applicability of such device. Access manholes, with a minimum diameter of 24 inches, shall be provided over each chamber and sanitary tee. The access manholes shall extend at least to finished grade and be designed and maintained to prevent water inflow or infiltration. If the tank is located in an area subject to vehicular traffic, the tank shall be constructed for traffic rated locations and the manhole rings and risers shall be designed and constructed for H-201oading. The manholes shall also have readily removable covers to facilitate inspection, grease removal, and wastewater sampling activities. (2) All interceptors shall be located outside of the building in such a manner that personnel from Hillsborough can inspect the interceptors at any time. (3) (4) A site plan showing the location of the interceptor, lines and cleanout or manhole; Details of the interceptor, lines and cleanout or manhole; (~ Formula and calculations used to determine the interceptor capacity. (5) Every interceptor shall have sufficient capacity to pertorm the service for which it is provided. Interceptors shall be designed to provide for a minimum hydraulic retention time of 24 minutes at actual peak flow or 12 minutes at the plculated theoretical peak flow rate as predicted by the Uniform Plumbing Code fixture criteria, between the influent and effiuent baffles with 20 percent of the total volume of the grease interceptor being allowed for sludge to settle and accumulate. Four different design methods will be available for use based on the needs of the facility. Method 1 bases the size of the device upon the number of kitchen drainage fixtures; Method 2 (EPA-1) bases the size of the device upon the number of seats in a facility Method 3 (EPA-2) bases the size of the device upon the number of meals served each day; and Method 4 uses NCDEH standards. All four methods are on file in the engineer's office. (6) (~) (8) Hillsborough shall be notified of any changes of operation or process at the permitted establishment. The establishment may be required to upgrade its grease interceptor to meet current requirements and standards. The following documents shall be submitted to Hillsborough for review and approval prior to issuance of a permit for installation of an interceptor. Any changes to the approved plan shall be approved by Hillsborough, prior to implementation. All grease traps and interceptors must be designed using standard engineering principles for sedimentation and floatation in gravity separators. Baffles and good inlet design are required to deflect the flow across the surface areas of the units and sufficient grease and solids storage capacity is required. Grease traps and interceptors shall be rated for the designed flow-through rate of the unit in gallons/minute. Grease interceptors shall be installed by users as required by Hillsborough. Grease interceptors shall be installed at the user's expense. All grease interceptors shall be of a type, design, and capacity approved by Hillsborough and shall be readily and easily accessible for cleaning and inspection. All such grease interceptors shall be serviced and emptied of accumulated waste contents as required in order to maintain minimum design capabilities or effective volume of the grease interceptor, but not less frequently than once every 60 days. Grease interceptors shall be installed to handle only discharge from food preparation, handling and cleaning areas that generate grease components. Domestic waste is to go directly into the sanitary sewer without passing through the interceptor. Existing establishments. (1) Businesses and other locations subject to this chapter which were in operation before the effective date of the ordinance from which this subsection is derived (Existing establishments) and do not have grease interception systems are generally required to install such a system within one year of the effective date of this regulation. Such business may receive approval from the town engineer or his designee, to install a system under alternate standards taking into account the circumstances of the business's operation, production of waste grease, and the practicality of installation under normal requirements. (2) Existing businesses with an existing grease interception system that does not meet Hillsborough's standards may be required to upgrade the system or may be allowed to continue use of the present system subject to requirements such as a clean out frequency less than 60 days.