Grease Management: Grease Waste Plumbing, Interceptor Design and JCW Inspections
Johnson County Wastewater (JCW) permitting is required for all Food\Beverage Service\Prep Facilities (FSF) and for interceptor installations, replacements and repairs. JCW’s FOG\Commercial Review Team may be contacted at 913-715-8520 for information about JCW’s permitting and inspection processes.
Grease Waste Plumbing
The following are requirements for fixture plumbing in Food Service Facilities in JCW's service area:
- Grease Waste Fixtures:
a. Toilets, urinals and similar domestic waste fixtures SHALL NOT be connected to the interceptor.
b. Garbage disposals or grinders are prohibited in new food service facilities.
c. The following fixtures MUST NOT be connected to the grease interceptor:
i. Drains receiving condensate.
ii. Drink station and ice machine drains.
iii. Bar sinks not receiving significant quantities of grease.
iv. Hot and cold well drains.
v. Hand wash sinks in general.
d. The following fixtures MUST be connected to the grease interceptor:
i. Dishmachines: Low temperature chemical (e.g., chlorine) sanitizing.
ii. 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.
iii. Two and three compartment sinks, prep sinks, pre-rinse sinks, dump sinks, etc.
iv. Mop sinks, utility sinks.
v. 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.
vi. Floor and trench drains in grease-prone prep and cooking areas.
e. 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.
- 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) General
- Gravity grease interceptor (GGI) installations for food\beverage service\prep facilities (FSFs) permitted for use in Johnson County Wastewater’s (JCW’s) service area 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 a standard concrete gravity grease interceptor, use JCW's Standard Concrete Gravity Grease Interceptor Detail and modify the detail to reflect the required volume and piping arrangement for the project.
- 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. See the JCW Accepted Non-Concrete Gravity Grease Interceptor Unit List for accepted unit(s) and contact JCW to obtain the current JCW accepted detail before applying for the JCW permit. FSF projects with a NCGGI will be accepted for review only if the proposed interceptor unit has been accepted by JCW. Refer manufacturers to the JCW Non-Concrete Gravity Grease Interceptor Unit Acceptance Criteria for Manufacturers for unit requirements and review information.
Gravity Grease Interceptor (GGI) Sizing
1. For all new interceptors and replacements, a Kansas PE shall determine the Drainage Fixture Units (DFUs) connected to the gravity interceptor in accordance with JCW grease waste plumbing standards and in correlation with UPC criteria and size the interceptor as follows:
a. 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 UPC Table 709.2) and as noted in the Drainage Fixture Unit (DFU) Value Calculations Table.
b. 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.
c. 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(b)) as noted in the DFU Calculations Table below.
d. 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 UPC Section 709.3) and added to the DFU Calculations Table.
e. Include the Drainage Fixture Unit Value (DFU) Calculations Table with the sealed interceptor sizing calculations.
2. Gravity interceptor volume shall be sized using the calculated DFUs and the following Gravity Grease Interceptor Volumes table (per UPC 1014.3.6) with 1000 gal minimum and 2000 gal maximum:
|Gravity Grease Interceptor Volumes
Drainage Fixture Units (DFUs)
|Interceptor Volume (gal)
|Up to 35
|Up to 90
|Up to 172
|Up to 216
3. Where DFUs for a future FSF(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’s FOG\Commercial Review team at 913-715-8520 to discuss options.
Hydromechanical Grease Interceptors (HGIs) General
- Only Hydromechanical Grease Interceptor (HGI) units accepted by JCW may be permitted and used for new installations and replacements in JCW’s service area. Please see the JCW Accepted Hydromechanical Grease Interceptor Unit List for accepted HGI units and contact JCW to obtain the current JCW HGI Unit Installation Detail for the selected unit.
- FSF projects will be accepted for review only if the proposed interceptor unit has been accepted by JCW. Refer manufacturers to the JCW Hydromechanical Grease Interceptor Unit Acceptance Criteria for Manufacturers for unit requirement and review information.
- 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 Interceptor (HGI) Sizing
1. For a FSF with a known FSF operator:
Provide grease production calculations (sealed by a Kansas PE) using the proposed number of meals per day provided by the FSF owner\operator in the JCW Food\Beverage Facility Supplemental Application and the grease production value based on the type of FSF. Select the Grease Production Value from Table 8-3 and refer to the calculation example below. Contact a JCW FOG\Commercial Group member at 913-715-8520 to discuss Restaurant Type for facilities not found in the Examples Table.
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
||Grease Production Values
Low Grease Producer
0.005 lbs/meal (no flatware)
|Elementary cafeteria, grocery meat department, hotel breakfast bar, sub shop, sushi, take and bake pizza
|0.065 lbs/meal (with flatware)
Medium Grease Producer
|0.025 lbs/meal (no flatware)
||Cafe, coffee shop, convenience store, grocery deli, Greek, Indian, Japanese, Korean, Thai, Vietmanese
|0.0325 lbs/meal (with flatware)
|High Grease Producer
||0.035 lbs/meal (no flatware)
||Full-fare family, fast-food hamburger, hamburger bar and grill, German, Italian, fast-food Mexican
|0.0455 lbs/meal (with flatware)
|Very High Grease Producer
||0.058 lbs/meal (no flatware)
||Full-fare BBQ, fast-food fried chicken, full-fare Mexican, steak and seafood, Chinese, Hawaiian
|0.075 lbs/meal (with flatware)
Grease Production Calculation Example : A full fare BBQ FSF 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.
- For a future FSF with an unknown FSF operator:
a. Provide grease production calculations 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.
b. A minimum 2500 lb grease capacity unit is required for a space up to 3500 square feet.
c. A single larger unit is required if the estimated grease production exceeds 2500 lbs in 90 days.
- Hydromechanical units may not be used for multiple tenant Common Interceptor installations.
A FSF with an existing interceptor in proper operating condition that is not required to have an interceptor (or a non-FSF tenant moving in to a former FSF space) must request JCW evaluation of the following options:
1. Request a Pumping Variance to reduce pumping frequency. Or,
2. Temporary Decommissioning. If JCW has verified the interceptor is in proper operating condition, the Building Owner and FSF may request temporary permanent decommissioning of the interceptor. All temporarily decommissioned interceptors shall be pumped on reduced pumping frequency.
3. Permanent Decommissioning. Interceptors that are not in proper operating condition must be permanently decommissioned.
Contact JCW’s FOG\Commercial Review team at 913-715-8520 to discuss options and for complete requirements.
- Existing Interceptors - A pre-application inspection is required for all facilities with an existing interceptor. Contact JCW’s FOG\Commercial Review team at 913-715-8520 to schedule the inspection.
- Interior Grease Waste Piping - Johnson County Wastewater shall inspect the interior plumbing fixtures attached to the interceptor before the plumbing is covered as noted on the JCW Permit. Schedule this inspection through the project record at mygovernmentonline.org.
- New, Replacement or Repaired Interceptors - Johnson County Wastewater shall inspect the interceptor, interceptor repairs and exterior piping prior to backfilling and after inspection of the interior piping at several stages of the installation or repair as noted on the JCW Permit. Schedule these multiple inspections through the project record at mygovernmentonline.org.
- Operating Permit Inspection – Two weeks before the opening of the FSF, schedule the required FSF Opening Inspection – BMPs and Education through the project record at mygovernmentonline.org.