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Towns of Cary and Morrisville
Public Works and Utilities Department
Pretreatment Division

Grease Interceptor Installation and Inspection Process
Preliminary Information

The Owner, Engineer, or Architect should refer to the Town of Cary Website for food service establishment fats, oils and grease control applicability and requirements, and contact the Town of Cary Public Works and Utilities Department Pretreatment Division at (919) 319-4564 or (919) 462-2072.

During project design and development, Town of Cary grease interceptor and plumbing code requirements need to be considered and incorporated in the plumbing design plan. Local health code officials; such as Wake County Environmental Services or the North Carolina Department of Agriculture should be consulted for requirements, as they may affect the number and type of kitchen fixtures required for a food service establishment (FSE). The Fats, Oils, and Grease Control Program requirements are intended to protect the Town’s wastewater collection and treatment system.

Items to consider when designing a grease interceptor system:

· Determine if project is considered a food service establishment and is required to meet the Town’s Fats, Oils, and Grease Control Program requirements

· Determine if physical constraints exist for the installation of a properly sized grease interceptor in a pre-existing facility – See Grease Interceptor Determination and Requirements Document

· Have clear understanding of plumbing equipment schedules

· Garbage disposals and waste food grinders required by Town of Cary municipal sewer use code to connect to an appropriately sized grease interceptor. Grease interceptor sizing is increased to account for food solids and grease accumulation.

· Review requirements of other local agencies (Wake County Environmental Services, NC Department of Agriculture, Plumbing Code, etc.)

· Placement of grease interceptor (accessibility, vehicular/foot traffic, odor, etc.)

· Grease interceptor sizing related to service frequency requirements. Over sizing may result in reduced cleaning frequencies; however, may also lead to odor issues and difficulties in adequate and effective cleaning

· Existing or proposed sewer and plumbing elevations

· Future possibilities of facility kitchen expansion or changes in menu that could alter the grease interceptor adequacy

· Community grease interception (grease interceptor shared and used by more than one FSE)

· Time or initiation of grease interceptor installation; during utilities installation, or with building construction

· Contact the Town of Cary Pretreatment Division for preliminary review of grease interceptor proposals

Items needed for grease interceptor sizing:

FSE layout/proposals may include any of the following, but are not limited to:

Total number and Dimensions (inches)

· 1, 2, 3-compartment sinks and drain size

· Utility sinks

· Grease contributing equipment (rotisserie, chinese stove (wok), tilt kettles, etc.)

Discharge flow rate (gallons per minute) per manufacturer specifications

· Dishwashers

· Pre-rinse sinks and drain size (faucet supply flow rate)

· Prep sinks and drain size (faucet supply flow rate)

· Can Wash / Mop sink hose bibs (faucet supply flow rate)

· Garbage disposals / Food Waste Grinders / Pulpers (water supply flow rate)

· Exhaust Hood(s) (self cleaning, water supply flow rate)

· Kitchen floor surface area - square footage (sum of cooking, food prep, serving, and dishwashing areas)

Using the Town of Cary Grease Interceptor Sizing Spreadsheet; include all applicable sink dimensions, flow rates, pipe diameter, and floor surface area. Once you have sized the grease interceptor, contact the Pretreatment Division at (919) 319-4564 or (919) 462-2072 for review and approval. Equipment and information used in sizing said grease interceptor shall reflect in the building plumbing plan submittal.

Permit Application and Plan Review Submittal

The Owner, Engineer, or Architect should refer to the Town of Cary Inspections and Permits Department website at www.townofcary.org for permit application and plan submittal requirements in the Town of Cary. Projects located in the Town of Morrisville shall refer to the Town of Morrisville Inspections Department website at www.ci.morrisville.nc.us for permit application and plan submittal requirements

Plan review submittals with information pertaining to the installation of a grease interceptor should include:

New Construction, Major Renovation Existing Facilities - Plan Submittal

1. Project owner name

2. Proposed facility name

3. Project location

4. Project design group information/Engineer (sealed by PE)

5. Plumbing equipment schedule

6. Plumbing plan layout (sewer, greasy waste, and storm (if applicable))

7. Isometric plumbing layout

8. Kitchen equipment schedule

9. Grease interceptor sizing spreadsheet summary (sink types, dimensions, sink drain pipe size)

10. Grease interceptor location (proximity to kitchen, service, potential odors)

11. Grease interceptor detail and size (Town of Cary Design or Town approved design)

12. Grease interceptor construction material type

13. Grease interceptor traffic rating (H-20 bridge loaded required if subject to vehicular traffic)

14. Inlet and outlet sanitary tee design detail (Town of Cary Design)

15. Grease interceptor sample vault detail (Town of Cary Design)

Existing Facility with pre-approved alternative grease interception – Plan Submittal

1. Project owner name
2. Proposed facility name
3. Project location
4. Project design group information/Engineer (sealed by PE)
5. Plumbing equipment schedule
6. Plumbing plan layout (sewer, greasy waste, and storm (if applicable))
7. Isometric plumbing layout
8. Kitchen equipment schedule
9. Kitchen equipment layout
10. Grease trap manufacturers spec sheet with make, model, design
11. Grease interceptor location (proximity to kitchen, service, potential odors)
12. Type of installation (on-floor, in-floor, exterior)
13. Type of fixture connection (direct, in-direct)

In-field Grease Interceptor Installation Inspections

The Town of Cary Pretreatment Division will conduct in-field inspections to confirm the size, design, and installation of plan review approved grease interceptors. The Pretreatment Division conducts its inspections independent of the Town’s Inspection and Permits Department Plumbing Inspections. The plumbing contractor or engineer should contact the Pretreatment Division for approval at the following stages of construction for inspection in order to not delay final inspections and the facilities Certificate of Occupancy:

Groundwork Grease Interceptor Inspection – Inspection of all below slab or in-ground grease interceptor installations. It is expected that the interceptor (with sample vault, if applicable) will be installed in the proper orientation, level, correct size/design, and interceptor risers/covers installed prior to back filling the excavated site. At the contractors’ discretion, groundwork inspections may include the installation of inlet and outlet sanitary tees, baffle wall grouting (sides and bottom – if needed) and sample vault slope installation; however, these inspections are typically associated with a rough-in inspection.

Rough-In Grease Interceptor Inspection – Inspection of inlet and outlet sanitary tees, baffle tees, grouted baffle wall (sides and bottom - if needed) and sample vault slope installation. In special cases the inspection of all grease waste plumbing lines that are located in the wall for special case/alternative interior grease interceptors prior to covering with wall finishes.

Final Grease Interceptor Inspection – Inspection of grease interceptor risers/covers at final finish grade and review of installed sink fixtures connecting to the interceptor. It is expected that the grease interceptor access will be at a minimum flush with final finish grade and all noted corrections from previous inspection complete.

The Pretreatment Division will record all inspections on an inspector’s report and will be placed in the permit box where one copy will be required to remain at all times with the permit card and a second copy will be available for the Contractors records. The Pretreatment Division will notify the Plumbing Inspector of the grease interceptor inspection result for their future plumbing inspections and review.

The Pretreatment Division reminds the Contractor that a comments sheet is included with your permit card. The comment sheet should be reviewed for any comments or requirements that were made in addition to what is included on an approved set of construction plan.

Failure to complete previously noted deficiencies or complete installations at the appropriate inspection phase may result in the issuance of a $50 re-inspection fee.

Note: Town of Cary Pretreatment Division plan review, inspection, and approval are strictly for adherence to the Town's Sewer Use Ordinance requirements. All Building and construction code requirements shall be administered by the qualified local code enforcement official. Pretreatment Division review and approval shall not be construed as a building ro construction code official review or approval.

If there are any questions regarding the installation of a grease interceptor or the required inspections, please feel free to contact the Pretreatment Division at (919) 319-4564 or (919) 462-2072.