ADOPTS WITH AMENDMENTS:

International Plumbing Code 2015 (IPC 2015)

Heads up: There are no amended sections in this chapter.
This chapter shall govern the material and installation of traps, interceptors and separators.
Each plumbing fixture shall be separately trapped by a liquid-seal trap, except as otherwise permitted by this code. The vertical distance from the fixture outlet to the trap weir shall not exceed 24 inches (610 mm), and the horizontal distance shall not exceed 30 inches (610 mm) measured from the centerline of the fixture outlet to the centerline of the inlet of the trap. The height of a clothes washer standpipe above a trap shall conform to Section 802.3.3. A fixture shall not be double trapped.

Exceptions:
  1. This section shall not apply to fixtures with integral traps.
  2. A combination plumbing fixture is permitted to be installed on one trap, provided that one compartment is not more than 6 inches (152 mm) deeper than the other compartment and the waste outlets are not more than 30 inches (762 mm) apart.
  3. A grease interceptor intended to serve as a fixture trap in accordance with the manufacturer's installation instructions shall be permitted to serve as the trap for a single fixture or a combination sink of not more than three compartments where the vertical distance from the fixture outlet to the inlet of the interceptor does not exceed 30 inches (762 mm) and the developed length of the waste pipe from the most upstream fixture outlet to the inlet of the interceptor does not exceed 60 inches (1524 mm).
  4. Floor drains in multilevel parking structures that discharge to a building storm sewer shall not be required to be individually trapped. Where floor drains in multilevel parking structures are required to discharge to a combined building sewer system, the floor drains shall not be required to be individually trapped provided that they are connected to a main trap in accordance with Section 1103.1.
Fixture traps shall be self-scouring. Fixture traps shall not have interior partitions, except where such traps are integral with the fixture or where such traps are constructed of an approved material that is resistant to corrosion and degradation. Slip joints shall be made with an approved elastomeric gasket and shall be installed only on the trap inlet, trap outlet and within the trap seal.
The following types of traps are prohibited:
  1. Traps that depend on moving parts to maintain the seal.
  2. Bell traps.
  3. Crown-vented traps.
  4. Traps not integral with a fixture and that depend on interior partitions for the seal, except those traps constructed of an approved material that is resistant to corrosion and degradation.
  5. "S" traps.
  6. Drum traps.
Exception: Drum traps used as solids interceptors and drum traps serving chemical waste systems shall not be prohibited.
Each fixture trap shall have a liquid seal of not less than 2 inches (51 mm) and not more than 4 inches (102 mm), or deeper for special designs relating to accessible fixtures.
Trap seals of emergency floor drain traps and trap seals subject to evaporation shall be protected by one of the methods in Sections 1002.4.1.1 through 1002.4.1.4.
A potable water-supplied trap seal primer valve shall supply water to the trap. Water-supplied trap seal primer valves shall conform to ASSE 1018. The discharge pipe from the trap seal primer valve shall connect to the trap above the trap seal on the inlet side of the trap.
A reclaimed or gray water-supplied trap seal primer valve shall supply water to the trap. Water-supplied trap seal primer valves shall conform to ASSE 1018. The quality of reclaimed or gray water supplied to trap seal primer valves shall be in accordance with the requirements of the manufacturer of the trap seal primer valve. The discharge pipe from the trap seal primer valve shall connect to the trap above the trap seal, on the inlet side of the trap.
A waste water-supplied trap primer device shall supply water to the trap. Waste water-supplied trap primer devices shall conform to ASSE 1044. The discharge pipe from the trap seal primer device shall connect to the trap above the trap seal on the inlet side of the trap.
A barrier-type trap seal protection device shall protect the floor drain trap seal from evaporation. Barrier-type floor drain trap seal protection devices shall conform to ASSE 1072. The devices shall be installed in accordance with the manufacturer's instructions.
Fixture trap size shall be sufficient to drain the fixture rapidly and not less than the size indicated in Table 709.1. A trap shall not be larger than the drainage pipe into which the trap discharges.
Building (house) traps shall be prohibited.
Traps shall be set level with respect to the trap seal and, where necessary, shall be protected from freezing.
A recess provided for connection of the underground trap, such as one serving a bathtub in slab-type construction, shall have sides and a bottom of corrosion-resistant, insect- and verminproof construction.
Where a vitrified clay or other brittleware, acid-resisting trap is installed underground, such trap shall be embedded in concrete extending 6 inches (152 mm) beyond the bottom and sides of the trap.
In mental health centers, pipes and traps shall not be exposed.
Interceptors and separators shall be provided to prevent the discharge of oil, grease, sand and other substances harmful or hazardous to the public sewer, the private sewage system or the sewage treatment plant or processes.

1003.2 Approval

AMENDMENT
This section has been amended at the state or city level.
Interceptors and separators shall be designed and installed in accordance with the manufacturer's instructions and the requirements of this section based on the anticipated conditions of use. Wastes that do not require treatment or separation shall not be discharged into any interceptor or separator. No interceptor or separator shall be installed until its design, size, location and venting has been approved by the local jurisdictional code official. The local jurisdictional code official shall have the authority to require a grease interceptor to be serviced, repaired, or replaced with a larger unit when it is determined that a unit is not working or being maintained properly, the unit is damaged, or the mode of operation of the facility no longer meets the anticipated conditions of use (i.e., offensive odors, sewage backups or overflows, or when it is determined that grease is bypassing the grease interceptor and causing downstream blockages or interfering with sewage treatment).

1003.2.1 Grease Interceptor Sizing

AMENDMENT
This section has been amended at the state or city level.
In all instances of new construction, change of occupancy classification or use of the property, a gravity grease interceptor or hydro-mechanical grease interceptor meeting the minimum capacity as required by this Section of the Code shall be installed. The minimum required capacity (volume) of the grease interceptor shall be determined based upon the maximum number of persons served during the largest meal period. The minimum capacity shall not be less than 125 gallons below the static water level. This capacity is sufficient to hold the flow from one meal long enough to accomplish proper grease separation when serving up to 50 people during a single meal period. When over 50 people are served during a single meal period, the minimum capacity shall be increased beyond 125 gallons based upon at least an additional 2 1/2 gallons per person beginning with the 51st person served and greater. 

Exception:
  1. At the discretion of the local jurisdictional code official, a smaller, point of use type hydro-mechanical grease interceptor or automatic grease removal device may be permissible when:
    1. a concrete slab would have to be broken at an existing building or facility for the proper installation of a grease interceptor; or
    2. an outside, unpaved area surrounding an existing building where a grease interceptor could be installed is available; however, it is determined that the area is located further than 75 feet from the plumbing fixtures that the grease interceptor would be servicing; or
    3. the local jurisdictional code official determines that the installation is unfeasible such as when servicing a kitchen located on the upper floors of a multistoried building; or
    4. the local jurisdictional code official determines that minimal fat, oil and grease will be produced or introduced into the sanitary drainage system based on the menu and mode of operation of the facility (i.e., snowball stands, sandwich shops, or other similar facilities with low grease production and which utilize single-service tableware and hollowware including forks, knives, spoons, plates, bowls, cups, and other serving dishes).
  2. In these instances, listed under the exception, the minimum required size of the hydromechanical grease interceptor; fats, oils and greases disposal system or automatic grease removal device shall be determined in accordance with the requirements of Section 1003.3.4 of this code. In no case shall a grease interceptor or automatic grease removal device be installed which has an approved rate of flow of less than 20 gallons per minute.
Grease interceptors shall comply with the requirements of Sections 1003.3.1 through 1003.3.5.
A grease interceptor or automatic grease removal device shall be required to receive the drainage from fixtures and equipment with greaseladen waste located in food preparation areas, such as in restaurants, hotel kitchens, hospitals, school kitchens, bars, factory cafeterias and clubs. Fixtures and equipment shall include pot sinks, prerinse sinks; soup kettles or similar devices; wok stations; floor drains or sinks into which kettles are drained; automatic hood wash units and dishwashers without prerinse sinks. Grease interceptors and automatic grease removal devices shall receive waste only from fixtures and equipment that allow fats, oils or grease to be discharged. Where lack of space or other constraints prevent the installation or replacement of a grease interceptor, one or more grease interceptors shall be permitted to be installed on or above the floor and upstream of an existing grease interceptor.
Where food waste disposers connect to grease interceptors, a solids interceptor shall separate the discharge before connecting to the grease interceptor. Solids interceptors and grease interceptors shall be sized and rated for the discharge of the food waste disposers. Emulsifiers, chemicals, enzymes and bacteria shall not discharge into the food waste disposer.
When specifically allowed under the exception of Section 1003.2.1 of this code, hydromechanical grease interceptors; fats, oils, and greases disposal systems and automatic grease removal devices shall be sized in accordance with ASME A112.14.3, ASME A112.14.4, ASME A112.14.6, CSA B481.3 or PDI-G101. Hydromechanical grease interceptors; fats, oils, and grease disposal systems and automatic grease removal devices shall be designed and tested in accordance with ASME A112.14.3, ASME A112.14.4, CSA B481.1, PDI G101 or PDI G102. Hydromechanical grease interceptors; fats, oils, and greases disposal systems and automatic grease removal devices shall be installed in accordance with the manufacturer's instructions. Where manufacturer's instructions are not provided, hydromechanical grease interceptors; fats, oils, and greases disposal systems and automatic grease removal devices shall be installed in compliance with ASME A112.14.3, ASME A112.14.4, ASME A112.14.6, CSA B481.3 or PDI-G101.
Grease interceptors shall have the grease retention capacity indicated in Table 1003.3.4.1 for the flow-through rates indicated.

TABLE 1003.3.4.1
CAPACITY OF GREASE INTERCEPTORSa
TOTAL FLOW-THROUGH
RATING (gpm)
GREASE RETENTION
CAPACITY (pounds)
4 8
6 12
7 14
9 18
10 20
12 24
14 28
15 30
18 36
20 40
25 50
35 70
50 100
75 150
100 200

For SI: 1 gallon per minute = 3.785 L/m, 1 pound = 0.454 kg.
  1. For total flow-through ratings greater than 100 (gpm), double the flow-through rating to determine the grease retention capacity (pounds).
Grease interceptors shall be equipped with devices to control the rate of water flow so that the water flow does not exceed the rated flow. The flow-control device shall be vented and terminate not less than 6 inches (152 mm) above the flood rim level or be installed in accordance with the manufacturer's instructions.
Where automatic grease removal devices are installed, such devices shall be located downstream of each fixture or multiple fixtures in accordance with the manufacturer's instructions. The automatic grease removal device shall be sized to pretreat the measured or calculated flows for all connected fixtures or equipment. Ready access shall be provided for inspection and maintenance.
Gravity grease interceptors shall comply with the requirements of Sections 1003.3.46.1 through 1003.3.46.8 and shall be sized in accordance with Section 1003.2.1 of this code.
UpCodes note: There seems to be a typo in the section numbers referenced in this section. We are showing it as it appears in the LA Uniform Construction Code.

1003.3.6.1 Indoor Installations

AMENDMENT
This section has been amended at the state or city level.
If a gravity grease interceptor must be installed within an enclosed building, any access covers shall be gasketed to prevent the intrusion of odors into the building.

1003.3.6.2 Distance

AMENDMENT
This section has been amended at the state or city level.
The grease interceptor shall be placed as close to the plumbing fixture(s) discharging greasy waste as possible, but preferably on the outside of the building when feasible.

1003.3.6.3 Outlet Pipe

AMENDMENT
This section has been amended at the state or city level.
The minimum diameter of the outlet pipe shall not be less than 4 inches. The invert of the gravity grease interceptor outlet opening (i.e., lowest portion of the outlet pipe where it draws waste near the bottom of the grease interceptor), shall be located at a maximum of 6 inches and a minimum of 4 inches from the floor of the grease interceptor. This requirement also applies to any intermediate outlets in multi-compartment gravity grease interceptors.

1003.3.6.4 Air Space

AMENDMENT
This section has been amended at the state or city level.
A minimum of one foot of air space shall be provided above the static water level.

1003.3.6.5 Venting

AMENDMENT
This section has been amended at the state or city level.
A gravity grease interceptor outlet shall be properly vented in accordance with this section to prevent it from siphoning itself out. Any internally vented outlet line shall have the vent terminal extended to within 2 inches of the bottom of the access cover to prevent grease from escaping the gravity grease interceptor through the open vent terminal. For those gravity grease interceptors having a gasketed cover, the gravity grease interceptor outlet line shall not be allowed to be internally vented. In this case, the outlet line itself shall be vented with a minimum 2-inch vent pipe installed in accordance with Chapter 9 of this code.

1003.3.6.6 Water Seal

AMENDMENT
This section has been amended at the state or city level.
On unbaffled single compartment gravity grease interceptors, a 90 degree ell shall be used on the inlet and shall terminate 6 inches below the static water level. On baffled single compartment gravity grease interceptors, a baffle wall shall be placed between the inlet and outlet. The inlet shall discharge into the gravity grease interceptor at a level at least 6 inches below the top of the baffle wall.

1003.3.6.7 Minimum Horizontal Distance

AMENDMENT
This section has been amended at the state or city level.
The minimum horizontal distance between the inlet and outlet piping in the gravity grease interceptor shall be 24 inches.

1003.3.6.8 Access/Covers

AMENDMENT
This section has been amended at the state or city level.
Access from the top of the gravity grease interceptor shall be provided by an easily removable cover above an access opening for proper maintenance. Additional access opening/covers shall be provided as necessary to provide accessibility to each compartment in multicompartment or multi-baffled arrangements as well as access to both the inlet and outlet. Access opening covers shall be above or at grade (G) to provide ready accessibility. Each access cover shall be designed so that it cannot slide, rotate, or flip when properly installed in order that the opening is not unintentionally exposed. Especially for lightweight covers, mechanical fasteners are recommended to augment the safety of and ensure positive closure of the cover.
The discharge piping from a grease interceptor shall be directly connected to the sanitary drainage system.
At repair garages where floor or trench drains are provided, car washing facilities, factories where oily and flammable liquid wastes are produced and hydraulic elevator pits, oil separators shall be installed into which oil-bearing, grease-bearing or flammable wastes shall be discharged before emptying into the building drainage system or other point of disposal.

Exception: An oil separator is not required in hydraulic elevator pits where an approved alarm system is installed. Such alarm systems shall not terminate the operation of pumps utilized to maintain emergency operation of the elevator by fire fighters.
A mixture of treated or untreated light and heavy liquids with various specific gravities shall be separated in an approved receptacle.
Oil separators shall be listed and labeled, or designed in accordance with Sections 1003.4.2.1 and 1003.4.2.2.
Oil separators shall have a depth of not less than 2 feet (610 mm) below the invert of the discharge drain. The outlet opening of the separator shall have not less than an 18 inch (457 mm) water seal.
Where automobiles are serviced, greased, repaired or washed or where gasoline is dispensed, oil separators shall have a capacity of not less than 6 cubic feet (0.168 m3) for the first 100 square feet (9.3 m2) of area to be drained, plus 1 cubic foot (0.028 m3) for each additional 100 square feet (9.3 m2) of area to be drained into the separator. Parking garages in which servicing, repairing or washing is not conducted, and in which gasoline is not dispensed, shall not require a separator. Areas of commercial garages utilized only for storage of automobiles are not required to be drained through a separator.
Sand and similar interceptors for heavy solids shall be designed and located so as to be provided with ready access for cleaning, and shall have a water seal of not less than 6 inches (152 mm).
Clothes washers shall discharge through an interceptor that is provided with a wire basket or similar device, removable for cleaning, that prevents passage into the drainage system of solids 1/2 inch (12.7 mm) or larger in size, string, rags, buttons or other materials detrimental to the public sewage system.

Exceptions:
  1. Clothes washers in individual dwelling units shall not be required to discharge through an interceptor.
  2. A single clothes washer designed for use in individual dwelling units and installed in a location other than an individual dwelling unit shall not be required to discharge through an interceptor.
Bottling plants shall discharge process wastes into an interceptor that will provide for the separation of broken glass or other solids before discharging waste into the drainage system.
Slaughtering room and dressing room drains shall be equipped with approved separators. The separator shall prevent the discharge into the drainage system of feathers, entrails and other materials that cause clogging.
Interceptors and separators shall be designed so as not to become air bound. Interceptors and separators shall be vented in accordance with one of the methods in Chapter 9.

1003.10 Access and Maintenance of Interceptors and Separators

AMENDMENT
This section has been amended at the state or city level.
Access shall be provided to each interceptor and separator for service and maintenance. A two-way cleanout shall be provided on the discharge waste line immediately downstream of all interceptors and separators. Interceptors and separators shall be maintained by periodic removal of accumulated grease, scum, oil, or other floating substances and solids deposited in the interceptor or separator.
The materials and methods utilized for the construction and installation of traps, interceptors and separators shall comply with this chapter and the applicable provisions of Chapters 4 and 7. The fittings shall not have ledges, shoulders or reductions capable of retarding or obstructing flow of the piping.
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