Grease Interceptor Design Requirements

Grease interceptors are required for all Food Service Establishments (FSEs) that do not qualify for a Low Grease Discharge Waiver (LGDW).

Grease Waste Plumbing

Required Connections

The following fixtures SHALL connect to the grease interceptor:

  • Dishmachines: Low temperature chemical (e.g., chlorine) sanitizing
  • Dishmachines: High temperature sanitizing. Must include a device to mix cold water with the discharge to reduce the discharge temperature to 140° F or less.
  • Two and three compartment sinks, prep sinks, pre-rinse sinks, dump sinks, etc.
  • Mop sinks and/or utility sinks
  • Kitchen equipment drains (including the floor sinks serving the equipment) - wok drains, tilt kettles, ice cream/custard/etc. production machines, ice cream dipper wells, etc.
  • Floor and trench drains in grease-prone prep and cooking areas
  • Connect hand wash sinks to the sanitary line in general. Hand wash sinks may be connected to grease waste when the sanitary line is not in close proximity.

Prohibited Connections

​​​The following fixtures SHALL NOT connect to the grease interceptor:

  • Toilets, urinals and similar domestic waste fixtures
  • Garbage disposals or grinders
  • Drains receiving condensate
  • Drink station and ice machine drains
  • Bar sinks not receiving significant quantities of grease
  • Hot and cold well drains
  • Hand wash sinks in general


Interceptor venting must be connected to the building waste vent piping in accordance with the JCW accepted unit detail and the plumbing code.

Gravity Grease Interceptors (GGIs)


  • Gravity grease interceptor (GGI) installations shall be a single stand-alone unit with a minimum 1000 gallon and maximum 2000 gallon volume. Units in parallel shall not be used.  Units in series may generally not be used.
  • A 90-day pumping and cleaning frequency is standard.


For all new interceptors and replacements, provide sizing calculations (sealed by a Kansas PE) using the Drainage Fixture Units (DFUs) connected to the gravity interceptor in accordance with JCW grease waste plumbing standards and in correlation with 2015 IPC and 2015 UPC criteria and size the interceptor as follows:

  • DFU values for each fixture directly connected to the interceptor (including floor and trench drains) shall be included in the calculations. Each fixture shall be assigned value based on “Fixture Size” (per IPC Table 709.2) and be included in a Drainage Fixture Unit (DFU) value calculation table provided by the designer.
  • The DFU load of an indirect waste receptor (e.g. floor sinks) receiving the discharge of indirectly connected fixtures shall be the DFU value for the indirect waste receptor except as noted herein.
  • The DFU value for equipment with intermittent drainage (e.g. use the manufacturer’s rated “Flow” for commercial dishmachines) shall be assigned fixture unit values (per UPC Table 702.2(2)) as noted in the DFU Calculations Table below.
  • DFUs for equipment with continuous drainage (e.g. water-cooled wok range) shall be assigned 2 DFUs for each gallon per minute (GPM) of rated flow (per IPC Section 709.3) and added to the DFU Calculations Table.
  • Please see the  Drainage Fixture Unit Value (DFU) Calculations Table format and unit DFUs per Fixture Size or Flow.  Include a copy of the table (with the required unit DFUs per Fixture Size or Flow and including all project Fixture Description labels and counts (Qty) with the sealed interceptor sizing calculations.

Gravity interceptor volume shall be sized using the calculated DFUs and the following Gravity Grease Interceptor Volumes table (Table 8-2 from the ASPE Plumbing Engineering Design Handbook, Volume 4. (C) 2016, reprinted with permission from the American Society of Plumbing Engineers. All rights reserved.) with 1000 gal minimum and 2000 gal maximum:

Gravity Grease Interceptor Volumes
Drainage Fixture Units (DFUs) Interceptor Volume (gal)
Up to 35 1000
Up to 172 1500
Up to 216 2000

Where DFUs for a future FSE(s) are unknown, the interceptor shall be sized based on the maximum DFUs allowed for the pipe size (per UPC Table 703.2) connected to inlet of the interceptor. An inlet pipe size of 4 inches corresponds with up to 216 DFUs and a 2000 gallon interceptor. If the pipe size and corresponding number of DFUs may exceed 216, please contact JCW to discuss options.

Accepted Units

For a standard concrete gravity grease interceptor, use JCW's standard detail and modify the detail to reflect the required volume and piping arrangement for the project.

Grease Interceptor or Sand-Oil Interceptor Detail

Only Non-concrete Gravity Interceptor (NCGGI) Units accepted by JCW may be permitted and used for new installations and replacements in JCW’s service area.

Non-Concrete Gravity Interceptor (NCGGI) Units
Manufacturer Model Volume Material Detail
Zurn Proceptor GMC 1500(2) UPC 1500 Fiberglass PDF

Hydromechanical Grease Interceptors (HGIs)


  • A 90-day pumping frequency is standard.
  • A minimum 2500 lb interceptor grease capacity is required for facilities with grease production of up to 2500 lbs in the 90-day pump period.
  • A single larger unit with capacity meeting the calculated grease production estimate is required where grease production exceeds 2500 lbs in 90 days.
  • Hydromechanical units may not be used for multiple tenant Common Interceptor installations.


For a Food Service Establishment (FSE) with a known operator:
  • Provide grease production calculations (sealed by a Kansas PE) using the proposed number of meals per day provided by the FSE owner\operator in the JCW Food\Beverage Facility Supplemental Application and the grease production value based on the type of FSE. Select the Grease Production Value from Table 8-3 and refer to the calculation example below.
  • Grease Production Calculation Example:  A full-fare BBQ FSE serving approximately 350 meals per day on washable dishes and flatware with a 90-day pump schedule. Select the “Very high grease producer (with flatware)” value from Table 8-3 and calculate the daily grease load as follows: 350 meals per day × 0.075 lbs per meal = 26.25 lbs of grease per day. For a 90-day pump schedule at 26.25 lbs per day, 2362.5 lbs of grease storage capacity is required. The calculated capacity is less than JCW minimum 2500 lbs; therefore, use a minimum 2500 lb capacity HGI unit.
  • Table 8-3 is reprinted with permission from ASPE Plumbing Engineering Design Handbook, Volume 4. (C) 2016, American Society of Plumbing Engineers. All rights reserved.
Table 8-3 Example Grease Production Values for Restaurants
Restaurant Type Grease Production Values Examples
Low Grease Producer

0.005 lbs/meal (no flatware)

0.0065 lbs/meal (with flatware)

Elementary Cafeteria, Grocery Meat Department, Hotel Breakfast Bar, Sub Shop, Sushi, Take & Bake Pizza
Medium Grease Producer

0.025 lbs/meal (no flatware)

0.0325 lbs/meal (with flatware)

Cafe, Coffee Shop, Convenience Store, Grocery Deli, Greek, Indian, Japanese, Korean, Thai, Vietnamese
High Grease Producer

0.035 lbs/meal (no flatware)

0.0455 lbs/meal (with flatware)

Full-Fare Family, Fast-Food Hamburger, Hamburger Bar & Grill, German, Italian, Fast-Food Mexican
Very High Grease

0.058 lbs/meal (no flatware)

0.075 lbs/meal (with flatware)

Full-Fare BBQ, Fast-Food Fried Chicken, Full-Fare Mexican, Steak & Seafood, Chinese, Hawaiian

For a future Food Service Establishment (FSE) with an unknown operator:
  • Provide grease production calculations (sealed by a Kansas PE) based on square footage of the entire space. At minimum, use an average of 0.171 meals per square foot per day, a grease production value of 0.0455 lbs per meal and 90-day pump out.
  • A minimum 2500 lb grease capacity unit is required for a space up to 3500 square feet.
  • A single larger unit is required if the estimated grease production exceeds 2500 lbs in 90 days.

Accepted Units

Only Hydromechanical Grease Interceptor (HGI) units accepted by JCW may be permitted and used for new installations and replacements in JCW’s service area.

Hydromechanical Grease Interceptor (HGI) Units
Manufacturer Model Volume Material Detail
Schier GB-500 500 Polyethylene PDF
Schier GB-1000 1000 Polyethylene PDF