Current through Register Vol. 50, No. 9, September 20, 2024
D. Grease Traps, Grease
Interceptors, and Large Capacity Grease Interceptors. An approved type grease
trap, grease interceptor, or large capacity grease interceptor complying with
the provisions of this Section shall be installed in the waste line leading
from sinks, drains and other fixtures or equipment in establishments such as
restaurants, cafes, lunch counters, cafeterias, bars and clubs, hotels,
hospitals, sanitariums, factory, school or day care center kitchens, markets,
or other establishments where grease may be introduced into the drainage or
sewage system in quantities that can affect line stoppage or hinder sewage
treatment or the functioning of an individual sewerage system, except when, in
the opinion of the plumbing official, they are not necessary.
J. Special Occupancy
Provisions. Laundries, bottling plants and slaughter houses shall be provided
with an interceptor or separator in conformance with the following.
1. Laundries. Laundries shall be provided
with an interceptor as follows.
a.
Interceptor. Commercial laundries shall be equipped with an interceptor having
a removable wire basket or similar device that will prevent strings, rags,
buttons, or other materials detrimental to the sewerage system from passing
into the drainage system.
b.
Intercepting Basket/Device. The basket or other device shall prevent passage
into the drainage system of solids 1/2-inch (12.7 mm) or larger in size. The
basket or device shall be removable for cleaning purposes.
2. Bottling Plants. Bottling plants shall
discharge their process wastes into an interceptor which will provide for the
separation of broken glass or other solids, before discharging liquid wastes
into the drainage system.
3.
Slaughter House Drains. Slaughtering room drains shall be equipped with
separators which shall prevent the discharge into the drainage system of
feathers, entrails and other materials likely to clog the drainage
system.
K. Food Service.
The following special requirements apply to the handling of organic wastes of
food origin.
1. Commercial Food-Waste
Grinders. Where commercial food-waste grinders are installed, the waste from
those units shall discharge through a grease trap of an approved design for
this use.
2. Wash Racks. Every wash
rack and/or floor or slab used for cleaning containers and equipment exposed to
organic wastes of food origin shall be adequately protected against storm or
surface water and shall drain or discharge into a grease trap of an approved
design for this use.
L.
Maintenance. Grease traps, grease interceptors, large capacity grease
interceptors, and other types of interceptors and separators shall be
maintained in conformance with the following.
1. Grease Traps and Grease Interceptors.
Grease traps, grease interceptors, and large capacity grease interceptors shall
be maintained in efficient operating condition by periodic removal of the
accumulated grease. No such collected grease shall be introduced into any
drainage piping or sewerage system.
2. Interceptors and Separators in General.
Interceptors and separators of all types shall be maintained in efficient
operating condition by periodic removal of accumulated material for which the
interceptor or separator has been designed. No such collected material shall be
introduced into any drainage piping or sewerage system.
N. Procedures for
Design, Construction and Installation of Interceptors and Separators [formerly
Appendix M - Procedures for Design, Construction and Installation of
Interceptors and Separators]. The provisions of this Subsection shall apply to
the design, construction, installation and testing of interceptors and
separators required in accordance with Subsections A - M of
§1005 of this code.
1. Definitions. Definitions contained in
Chapter 2 of this code shall also apply to this Section except where the
following special definitions shall apply.
Bottling Plant Separator -an
interceptor designed to separate and retain broken glass and
other solids.
Grease Interceptor - an
interceptor of less than 125 gallon capacity which is designed
and installed so as to separate and retain grease. Typically identified by flow
rate and/or grease capacity and generally installed indoors adjacent to the
plumbing fixtures they serve. (See §1005. N.6 of this code for design and
sizing requirements.)
Grease Trap - an
interceptor of at least 125 gallon capacity which is designed
and installed to separate and retain grease. Typically identified by liquid
holding capacity (volume) and generally installed below
grade(G) outdoors with provisions for
above grade(G) accessibility for
cleaning purposes. (See §1005. N.3 of this code for sizing requirements and
§1005. N.4 of this code for design requirements.)
Large Capacity Grease Interceptor - an
interceptor of at least 125 gallon capacity conforming to ASME
A 112.14.3 or PDI-G101 which is designed and installed to separate and retain
grease. Generally manufactured to be installed above or below
grade(G) either indoors or outdoors.
(See §1005. N.3 of this code for sizing requirements and §1005. N.5 of this
code for design requirements.)
Laundry Trap - an
interceptor designed to separate and retain lint, strings,
rags, buttons or other similar materials which may be discharged from
laundries.
Oil Separator - an
interceptor designed to separate and retain waste oil and
other petroleum products.
Sand Interceptor - an
interceptor designed to separate and retain sand, gritty
material or other types of heavy solids.
Slaughter House Separator - an
interceptor designed to separate and retain feathers, entrails
and other similar substances.
Special Type Separator - an
interceptor designed to separate and retain deleterious,
hazardous or undesirable matter from normal wastes for proper disposal,
rendering, or recycling.
2.
General Regulations. The following general regulations are applicable to
interceptors and separators.
a. Size and
Type. The size and type of each interceptor or separator shall be in accordance
with the requirements of this Section and shall be approved by the plumbing
official.
b. Location. The location
of each interceptor or separator shall be approved by the plumbing
official.
c. Prior Approval. No
interceptor or separator shall be installed until its design, size, location
and venting has been approved by the plumbing official.
d. Cleanout on Discharge Line. A two-way
cleanout shall be provided on the discharge line immediately downstream of all
interceptors.
e. Grease
Traps/Grease Interceptors/Large Capacity Grease Interceptors. When it has been
determined under §1005. D of this code that a trap or interceptor is required,
the following regulations apply to the use of a grease trap or large capacity
grease interceptor versus the allowance of the use of a grease interceptor.
i. A grease trap or large capacity grease
interceptor shall be required in all instances of new construction or
substantial renovation of buildings or facilities. In addition, a grease trap
or large capacity grease interceptor shall be required for existing buildings
or facilities when a proper installation can be performed without the need to
break up a concrete slab.
ii. At
the discretion of the plumbing official, a grease interceptor may be allowed in
lieu of a grease trap or large capacity grease interceptor when the conditions
for a grease trap/large capacity grease interceptor installation do not exist
or cannot easily be met. For example, when:
(a). new construction, substantial renovation
of buildings or facilities is not being performed and a concrete slab would
have to be broken at the existing building or facility for the proper
installation of a grease trap;
(b).
an outside, unpaved area surrounding the building where a grease trap could be
installed is available; however, it is determined that the area is too far away
from the plumbing fixtures that the grease trap would be servicing;
or,
(c). the installation of a
grease trap is unfeasible such as when servicing a kitchen which is located on
the upper floors of a multistoried building.
3. Minimum Capacity of Grease
Traps and Large Capacity Grease Interceptors. The minimum required capacity of
grease traps and large capacity grease interceptors shall be determined based
upon the maximum number of persons served during the largest meal period in
accordance with the following:
a. General.
Grease traps and large capacity grease interceptors should be designed to be
large enough to allow the water contained within it to remain cold since only
cold water separates grease. In addition, grease traps and large capacity
grease interceptors should be designed to be large enough so that they require
cleaning at a frequency no more often than once per month.
b. Without Garbage Grinder. The minimum
capacity for applications without a garbage grinder 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 of the grease trap or
large capacity grease interceptor shall be increased beyond 125 gallons based
upon at least an additional 2 1/2 gallons per person beginning with the
511st person served and greater.
c. With Garbage Grinder. When a garbage
grinder is connected (see §1005. K.1 of this code), the grease trap or large
capacity grease interceptor shall have a minimum capacity of no less than 500
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 a garbage grinder is
connected and over 50 people are served during a single meal period, the
minimum grease trap capacity shall be increased beyond 500 gallons based upon
at least an additional 2 1/2 gallons per person beginning with the
51st person served and greater.
d. Alternate Sizing Methods. For
informational purposes only, alternate sizing methods may be found in Figures
9, 10, and 11 in
Section
1807 of this code.
4. Grease Traps. The following
regulations are applicable to the design and installation of grease traps.
a. The minimum required capacity of grease
traps shall be determined based upon the maximum number of persons served
during the largest meal period in accordance with §1005. N.3 of this
code.
b. If a grease trap must be
installed within an enclosed building, any access covers shall be gasketed to
prevent the intrusion of odors into the building.
c. A one compartment grease trap is
acceptable; however, a two compartment, or a one compartment grease trap with a
baffle wall between the inlet and outlet, is preferred.
d. The grease trap 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.
e. The minimum diameter of the outlet pipe
shall not be less than 4 inches.
f.
A minimum of one foot of air space shall be provided above the static water
level.
g. Venting. The following
regulations are applicable to the venting of grease traps:
i. The grease trap outlet shall be properly
vented to prevent the trap 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 grease trap
through the open vent terminal.
ii.
For those grease traps having a gasketed cover, the grease trap outlet line
shall not be allowed to be internally vented. In this case, the outlet line
itself shall have a 2-inch vent pipe properly installed.
h. The invert of the grease trap outlet
opening, at the point where water exits the grease trap, shall be located at a
maximum of 6 inches and a minimum of 4 inches from the floor of the grease
trap. This requirement also applies to any intermediate outlets in
multi-compartment grease traps. The invert of the inlet shall be at least 3
inches above the invert of the outlet.
i. On unbaffled single compartment grease
traps, a 90° ell shall be used on the inlet and shall terminate 6 inches below
the static water level. On baffled single compartment grease traps, a baffle
wall shall be placed between the inlet and outlet. The inlet shall discharge
into the grease trap at a level at least 6 inches below the top of the baffle
wall. The baffle wall shall extend from 2 inches below the static water level
to the bottom of the grease trap such that incoming water will have to overflow
above the top of the baffle wall in order to reach the outlet.
j. The horizontal distance between the inlet
and outlet piping in the grease trap should be sufficient to allow
gravity-differential separation to the grease so that it will not escape
through the outlet. The minimum horizontal distance shall be 24
inches.
k. Access/Covers. The
following regulations are applicable to the access to and the covers for grease
traps:
i. Access from the top of the grease
trap shall be provided by an easily removable cover above an access opening of
at least 20 inches square or 24 inches round. Additional access opening/covers
shall be provided as necessary to provide accessibility to each compartment in
multi-compartment 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.
ii. 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. (The intention is that a
child-resistant cover be provided. Especially for lightweight covers,
mechanical fasteners are recommended to augment the safety of and ensure
positive closure of the cover.)
l. No water jacketed grease trap shall be
approved or installed.
m. Each
grease trap shall have an approved water seal of not less than 2 inches in
depth or the diameter of its outlet, whichever is greater.
n. Abandoned grease traps shall be pumped and
filled as required for abandoned septic tanks in accord with LAC 51:XIII.715.V.
Click Here To View
Image
Figure 1005.N.4A (1 of 2) - Grease Trap (top
view)
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Image
Figure 1005.N.4A (2 of 2) - Grease Trap (side
view)
Click Here To View
Image
Figure 1005.N.4B - Grease Trap (sanitary details
only)
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Image
Figure 1005.N.4C - Grease Trap
5. Large Capacity Grease Interceptors. The
following design regulations are applicable to large capacity grease
interceptors.
a. Large capacity grease
interceptors shall be evaluated, tested, and certified for conformance with
ASME A 112.14.3 or PDI-G101.
b. The
minimum required capacity of large capacity grease interceptors shall be
determined based upon the maximum number of persons served during the largest
meal period in accordance with §1005. N.3 of this code.
c. Grease interceptors shall be maintained in
efficient operating condition by periodic removal of the accumulated grease. No
such collected grease shall be introduced into any drainage piping or sewerage
system.
d. Each grease interceptor
shall have an approved water seal of not less than 2 inches in depth or the
diameter of its outlet, whichever is greater. The grease interceptor outlet
shall be properly vented to prevent the trap from siphoning itself
out.
6. Grease
Interceptors. The following design regulations are applicable to grease
interceptors:
a. When specially allowed by
the plumbing official pursuant to §1005. N.2.e of this code, an approved type
grease interceptor complying with ASME A 112.14.3 or PDI-G101 and the
provisions of this Paragraph may be installed in the waste line leading from
sinks, drains and other fixtures or equipment in establishments such as
restaurants, cafes, lunch counters, cafeterias, bars and clubs, hotels,
hospitals, sanitariums, factory, school or day care center kitchens, markets,
or other establishments where grease may be introduced into the drainage or
sewage system in quantities that can affect line stoppage or hinder sewage
treatment or the functioning of an individual sewerage system, except when, in
the opinion of the plumbing official, they are not necessary.
b. The minimum required size of grease
interceptors shall be determined based upon fixture discharge rate (gpm) and
grease retention capacity (pounds) in accordance with Figure 1005.N.6 of this
code (see also §1005. N.6.h of this code); however, in no case shall a grease
interceptor be installed which has an approved rate of flow of less than 20
gallons per minute, except when specially approved by the plumbing
official.
c. Each plumbing fixture
or piece of equipment connected to a grease interceptor shall be provided with
an approved type flow control or restricting device installed in a readily
accessible and visible location in the tailpiece or drain outlet of each such
fixture. Flow control devices shall be so designed that the flow through such
device or devices shall at no time be greater than the rated capacity of the
grease interceptors. No flow control device having adjustable or removable
parts shall be approved.
d. Each
grease interceptor that is rated shall be stamped or labeled by the
manufacturer with an indication of its full discharge rate in gallons per
minute (gpm). Each grease interceptor allowed to be installed under the
provisions of this Paragraph shall have an approved rate of flow which is not
less than that given in Table 1005.N.6 of this code based upon the total flow
expected in gpm from the total number of connected fixtures (i.e., each grease
interceptor shall be rated equal to or greater than the incoming flow). The
total capacity, in gallons, from all fixtures discharging into any such grease
interceptor shall not exceed two and one-half (2-1/2) times the certified
gallon per minute (gpm) flow rate of the grease interceptor as per Table
1005.N.6 of this code.
i. Any grease
interceptor installed with the inlet more than 4 feet lower in elevation than
the outlet of any fixture discharging into such grease interceptor shall have
an approved rate of flow which is not less than 50 percent greater than that
given in Table 1005.N.6 of this code.
ii. For the purpose of this Paragraph, the
term "fixture" shall mean and include each plumbing fixture, appliance,
apparatus or other equipment required to be connected to or discharge into a
grease interceptor by any provision of this Paragraph.
e. Each fixture discharging into a grease
interceptor shall be trapped and vented in an approved manner. An approved type
grease interceptor may be used as a fixture trap for a single fixture when the
horizontal distance between the fixture outlet and the grease interceptor does
not exceed 4 feet and the vertical tailpipe or drain does not exceed 2 1/2
feet.
f. Grease interceptors shall
be maintained in efficient operating condition by periodic removal of the
accumulated grease. No such collected grease shall be introduced into any
drainage piping or sewerage system.
g. Each grease interceptor shall have an
approved water seal of not less than 2 inches in depth or the diameter of its
outlet, whichever is greater. The grease interceptor outlet shall be properly
vented to prevent the trap from siphoning itself out.
h. When grease interceptors are allowed to be
installed by the plumbing official in commercial kitchens, the recommended
sizing criteria is provided in Table 1005.N.6 of this code below.
|
Table 1005.N.6
Grease Interceptors
|
|
Required Rate of Flow Per Minute, Gallons
|
Grease Retention Capacity, Pounds
|
|
20
|
40
|
|
25
|
50
|
|
35
|
70
|
|
50
|
100
|
|
Procedure for Sizing Grease Interceptors
|
|
Steps
|
Formula
|
Example
|
|
1
|
Determine cubic content of fixture by multiplying
length x width x depth.
|
A sink 48" long by 24" wide by 12" deep.
Cubic content
48 x 24 x 12 = 13,824 cubic inches
|
|
2
|
Determine capacity in gallons. 1 gal = 231 cubic
inches
|
Contents in gallons
13,824 / 231 = 59.8 gallons
|
|
3
|
Determine actual drainage load. The fixture is
normally filled to about 75 percent of capacity with water. The items being
washed displace about 25 percent of the fixture content, thus actual drainage
load = 75 percent of fixture capacity.
|
Actual Drainage Load
0.75 x 59.8 = 44.9 gallons
|
|
4
|
Determine flow rate and drainage period. In general,
good practices dictate a 1-minute drainage period; however, where conditions
permit, a 2-minute drainage period is acceptable. Drainage period is the actual
time required to completely drain the fixture.
Flow rate = Actual Drainage Load / Drainage Period
|
Calculate flow rate for 1-minute period
44.9 / 1 = 44.9 gpm Flow rate
Two-minute period
44.9 / 2 = 22.5 gpm Flow Rate
|
|
5
|
Select interceptor which corresponds to the flow
rate calculated. Note: Select next larger size when flow rate falls between two
sizes listed.
|
For 1-minute period, 44.9 gpm requires PDI size
"50".
For 2-minute period, 22.5 gpm requires PDI size
"25".
|
Figure 1005.N.6
7. Oil Separators. The following regulations
are applicable to oil separators.
a. All
repair garages and gasoline stations with grease racks or grease pits, and all
factories which have oily wastes as a result of manufacturing, storage,
maintenance, repair, or testing processes shall be provided with an oil
separator which shall be connected to all necessary floor drains. The
separation of the vapor compartment shall be independently vented to the outer
air. If two or more separation or vapor compartments are used, each shall be
vented to the outer air or may connect to a header which is installed at a
minimum of 6 inches above the spill line of the lowest floor drain and vented
independently to the outer air. The minimum size of a flammable vapor vent
shall not be less than 2 inches, and when vented through a sidewall, the vent
shall not be less than 10 feet above the adjacent level at an approved
location. The interceptor shall be vented on the sewer side and this vent shall
not connect to a flammable vapor vent. All oil interceptors shall be provided
with gastight cleanout covers which shall be readily accessible. The waste line
shall not be less than 3 inches in diameter with a full-size two-way cleanout
brought to grade(G). When an interceptor is provided
with an overflow, it shall be provided with an overflow line (not less than 2
inches in diameter) to an approved waste oil tank having a minimum capacity of
550 gallons and meeting the requirements of the appropriate authority. The
waste oil from the separator shall flow by gravity or shall be pumped to a
higher elevation by an automatic pump. Pumps shall be adequately sized and
accessible. Waste oil tanks shall have a 2-inch minimum pumpout connection at
grade(G) and a 1 1/2-inch minimum vent to atmosphere at
an approved location at least 10 feet above
grade(G).
b. Each manufactured oil interceptor that is
rated shall be stamped or labeled by the manufacturer with an indication of its
full discharge rate in gallons per minute (gpm). The full discharge rate to
such an oil interceptor shall be determined at full flow. Each oil interceptor
shall be rated equal to or greater than the incoming flow and shall be provided
with an overflow line to an underground tank.
i. Oil interceptors not rated by the
manufacturer shall have a depth of not less than 2 feet below the invert of the
discharge drain. The outlet opening shall have not less than an 18-inch water
seal and shall have a minimum capacity as follows:
(a). where not more than three motor vehicles
are serviced and/or stored, oil interceptors shall have a minimum capacity of 6
cubic feet, and 1 cubic foot of capacity shall be added for each vehicle up to
10 vehicles; and
(b). above 10
vehicles, the plumbing official shall determine the size of the oil interceptor
required. Where vehicles are serviced only and not stored, oil interceptor
capacity shall be based on a net capacity of 1 cubic foot for each 100 square
feet of surface to be drained into the oil interceptor, with a minimum of 6
cubic feet.
c. A combination oil and sand interceptor may
be installed when the design is approved in writing by the plumbing official.
Click Here To View
Image
Figure 1005.N.7A - Oil Separator
Click Here To View
Image
Figure 1005.N.7B - Oil Separator Details
8. Sand Interceptors. The following
regulations are applicable to sand interceptors.
a. Multiple floor drains may discharge into
one sand interceptor.
b. Sand
interceptors shall be built of brick or concrete, prefabricated coated steel,
or other watertight material. The sand interceptor shall have an interior
baffle for full separation of the interceptor into two sections. The outlet
pipe shall be the same size as the inlet, the minimum being 3 inches, and the
baffle shall have two openings of the same diameter as the outlet pipe and at
the same invert as the outlet pipe. These openings shall be staggered so that
there cannot be a straight line flow between any inlet pipe and the outlet
pipe. The invert of the inlet pipe shall be no lower than the invert of the
outlet pipe.
i. The sand interceptor shall
have a minimum dimension of 2-feet square for the net free opening of the inlet
screen and a minimum depth under the invert of the outlet pipe of 24
inches.
ii. For each 5 gallons per
minute flow or fraction thereof over 20 gallons per minute, the area of the
sand interceptor inlet section is to be increased by 1 square foot. The outlet
section shall at all times have a minimum area of 50 percent of the inlet
sections.
iii. The outlet section
shall be covered by a solid removable cover set flush with the finished floor,
and the inlet section shall have an open grating set flush with the finished
floor and suitable for the traffic in the area in which it is
located.
c. Sand and
similar interceptors for every solid shall be so designed and located as to be
readily accessible for cleaning, shall have a water seal of not less than 6
inches, and shall be vented.
d.
Alternate designs for construction or baffling of sand interceptors complying
with the intent of this code may be submitted to the plumbing official for
approval.
Click Here To View
Image
Figure 1005.N.8 - Sand Interceptor
9. Laundry Traps. Laundry equipment that does
not have integral strainers shall discharge into an interceptor having a wire
basket or similar device that is removable for cleaning and that will prevent
passage into the drainage system of solids 1/2-inch or larger in maximum
dimension, such as string, rags, buttons or other solid materials detrimental
to the drainage system. The laundry trap (laundry interceptor/lint trap) and
its connection to the drainage system shall conform to the design depicted in
Figure 1005.N.9 of this Part. Any modifications of the design shall be approved
by the plumbing official. In additions, the size, location and venting of the
interceptor shall be approved by the plumbing official.
Click Here To View
Image
Figure 1005.N.9 - Lint Trap (with Non-Corrode
Basket)
10. Bottling
Separators. Bottling plants shall discharge their process waste water into an
interceptor/separator which will provide for the separation of broken glass or
other solids before discharging into the drainage system. The design, size,
location and venting of the bottling separator shall be approved by the
plumbing official.
11. Slaughter
House Separators. Slaughtering room drains shall be equipped with separators
which shall prevent the discharge into the drainage system of feathers,
entrails and other materials likely to clog the drainage system. The design,
size, location and venting of the slaughter house separator shall be approved
by the plumbing official.
12.
Special Type Separators
a. Every fish, fowl
and animal slaughter house or establishment and every fish, fowl and meat
packing or curing establishment and every soap factory, tallow rendering, fat
rendering and hide curing establishment, or any other establishment from which
considerable amounts of grease are likely to be discharged into any plumbing
system, community sewerage system, commercial treatment facility, or individual
sewerage system, shall be connected to and shall drain or discharge into a
grease trap meeting the requirements of this Section and approved by the
plumbing official for this use.
b.
Interceptors or separators for other special type applications shall not be
installed until their design, size, location and venting have been approved by
the plumbing official.
AUTHORITY NOTE:
Promulgated in accordance with
R.S.
40:4(A)(7) and
R.S.
40:5(2)(3)(7)(9)(16)(17)(20).
