Required gravity
grease interceptors shall comply with the provisions of Section 1014.3.1 through Section 1014.3.7.
The provisions of this section shall
apply to the design, construction, installation, and testing
of commercial kitchen gravity grease interceptors.
Waste
discharge in establishments from fixtures and equipment
which contain grease, including but not limited to,
scullery sinks, pot and pan sinks, dishwashers, soup kettles,
and floor drains located in areas where grease-containing
materials exist, shall be permitted to be drained
into the sanitary waste through the interceptor where
approved by the Authority Having Jurisdiction.
Toilets, urinals, and other similar fixtures shall not drain through the interceptor.
Waste shall enter the interceptor through the inlet pipe.
Gravity interceptors shall be constructed
in accordance with the applicable standard in
Table 1701.1 or the design approved by the Authority
Having Jurisdiction.
Each grease interceptor shall be so
installed and connected that it shall be easily accessible
for inspection, cleaning, and removal of the intercepted
grease. A gravity grease interceptor that complies with
IAPMO Z1001 shall not be installed in a building where
food is handled. Location of the grease interceptor shall
meet the approval of the Authority Having Jurisdiction.
Interceptors shall be
placed as close as practical to the fixtures they serve.
Each
business establishment for which a gravity grease
interceptor is required shall have an interceptor
which shall serve that establishment unless otherwise
approved by the Authority Having Jurisdiction.
Each gravity grease interceptor
shall be located to be readily accessible to the
equipment required for maintenance.
Gravity
grease interceptors shall be designed to remove grease
from effluent and shall be sized in accordance with this
section. Gravity grease interceptors shall also be
designed to retain grease until accumulations can be
removed by pumping the interceptor. It is recommended
that a sample box is located at the outlet end of gravity
grease interceptors so that the Authority Having Jurisdiction
can periodically sample effluent quality.
The volume of the interceptor
shall be determined by using Table 1014.3.6. Where
drainage fixture units (DFUs) are not known, the interceptor
shall be sized based on the maximum DFUs
allowed for the pipe size connected to the inlet of the
interceptor. Refer to Table 703.2, Drainage Piping, Horizontal.
For SI units: 1 gallon = 3.785 L
Notes:
Given: A restaurant with the following fixtures and equipment.
One food preparation sink; three-floor drains - one in the food prep area, one in the grill area, and one receiving the indirect waste from the ice machine and a mop sink.
Using Table 1014.3.6, the grease interceptor will be sized at 750 gallons (2389 L).
| DRAINAGE FIXTURE UNITS1,3 (DFUs) | INTERCEPTOR VOLUME2 (gallons) |
|---|---|
| 8 | 500 |
| 21 | 750 |
| 35 | 1000 |
| 90 | 1250 |
| 172 | 1500 |
| 216 | 2000 |
| 307 | 2500 |
| 342 | 3000 |
| 428 | 4000 |
| 576 | 5000 |
| 720 | 7500 |
| 2112 | 10000 |
| 2640 | 15000 |
Notes:
- 1 The maximum allowable DFUs plumbed to the kitchen drain lines that will be connected to the grease interceptor.
- 2 This size is based on DFUs, the pipe size from this code; Table 703.2; Useful Tables for flow in half-full pipes (ref: Mohinder Nayyar Piping Handbook, 3rd Edition, 1992). Based on 30-minute retention time (ref.: George Tchobanoglous and Metcalf & Eddy. Wastewater Engineering Treatment, Disposal, and Reuse, 3rd Ed. 1991 & Ronald Crites and George Tchobanoglous. Small and Decentralized Wastewater Management Systems, 1998). Rounded up to nominal interceptor volume.
- 3 Where the flow rate of directly connected fixture(s) or appliance(s) have no assigned DFU values, the additional grease interceptor volume shall be based on the known flow rate (gpm) (L/s) multiplied by 30 minutes.
EXAMPLE 1014.3.6
GRAVITY GREASE INTERCEPTOR SIZING EXAMPLE
GRAVITY GREASE INTERCEPTOR SIZING EXAMPLE
Given: A restaurant with the following fixtures and equipment.
One food preparation sink; three-floor drains - one in the food prep area, one in the grill area, and one receiving the indirect waste from the ice machine and a mop sink.
| Kitchen Drain Line DFU Count (from Table 702.1): | ||
|---|---|---|
| 3 floor drains at 2 DFUs each | = | 6 DFUs |
| Mop sink at 3 DFUs each | = | 3 DFUs |
| Food prep sink at 3 DFUs each | = | 3 DFUs |
| Total | = | 12 DFUs |
Using Table 1014.3.6, the grease interceptor will be sized at 750 gallons (2389 L).
Abandoned grease interceptors shall be pumped
and filled as required for abandoned sewers and sewage
disposal facilities in Section 722.0.