Grease Interceptor Sizing Using UPC - City of MilpitasGrease Interceptor Sizing Using UPC – Draft-Final June 6, 2017 W‐2978 City of San José 3 EEC 2.0 FIXTURE AND DRAIN CONNECTIONS

California WDR Subcommittee Group

June 6, 2017

Prepared for:

Grease Interceptor SizingUsing UPC(AC27650, SO #3)

Draft‐Final

Department of Environmental Services200 E. Santa Clara Street, 7th Floor

San Jose, California 95113

Grease Interceptor Sizing Using UPC – Draft-Final June 6, 2017

W‐2978 City of San José 2 EEC

1.0 INTRODUCTION Pursuant to Service Order No.3 of AC Contract No. AC27650, EEC Environmental (EEC) was tasked with assessing sizing of grease interceptors in accordance with the current Uniform Plumbing Code (UPC)1. The task includes identification of the fixtures and drains that are to connect to grease interceptors at food service establishments as well as assignment of the appropriate number of drainage fixture units (DFUs) for each fixture/drain, which factors into interceptor sizing. The task also includes discussion on the circumstances when a hydromechanical grease interceptor (HGI) can be a suitable alternative to a gravity grease interceptor (GGI). The purpose of the City’s FOG Control Program is to prevent grease blockages in the City’s sanitary sewer lines that can cause sanitary sewer overflows (SSOs). Key elements in controlling such blockages/SSOs include the use of grease interceptors as well as implementation of Best Management Practices (BMPs) at food service establishments (FSEs). Grease interceptors (aka: Grease Control Devices or GCDs) come in many shapes and sizes, each with their own benefits and deficiencies. Hydromechanical grease interceptors (HGI or trap) are smaller devices that can be installed above or below ground, as well as outside or inside of a facility. Gravity grease interceptors (GGIs) are larger in‐ground tanks, typically installed outside the facility. Because of their size, HGIs tend to be less expensive to install; however, due to their smaller size, multiple devices may be needed to treat the appropriate fixtures and drains and more frequent maintenance is required to ensure its proper operation. GGIs are more suitable for connection of all appropriate fixtures and drains to a single device and because of their relatively large sizes, typically require less frequent maintenance; however, GGIs are generally more expensive to install, particularly where an existing facility is being retrofitted with a GCD. Most types of grease interceptors can be effective in reducing FOG discharges to the sewer if:

The fixtures and drains with FOG‐laden wastewater are connected to the device

The device is property sized for the connected fixtures/drains

The device is properly installed and maintained The focus of this report is in ensuring the appropriate fixtures and drains are connected to the grease interceptor, the grease interceptor is sized appropriately, and the appropriate grease interceptor configuration is applied fairly and equitably.

1 EEC has been a national consulting leader on the pretreatment and processing of FOG for over 20 years. EEC’s 2004 national FOG control study for the Orange County Sanitation District (OCSD) and their 26 satellite agencies is still considered the largest study of its kind in addressing FOG related sewer blockages and SSO issues. EEC has extensive experience in grease interceptor design, sizing and installation, as well as grease interceptor configuration criteria development.



2.0 FIXTUREANDDRAINCONNECTIONSCurrent City of San Jose Code Section 15.14.630D states ‐ Waste discharged from fixtures and equipment in establishments which may contain grease or other objectionable materials including, but not limited to, scullery sinks, pot and pan sinks, dishwashers, food waste disposals, soup kettles, and floor drains located in areas where such objectionable materials may exist, may be drained into the sanitary sewer through the grease control device if approved by the director provided, however, that toilets, urinals, wash basins, and other fixtures containing fecal material shall not flow through the grease control device. Generally, all sinks, fixtures and/or drains in food preparation, cooking or dish washing areas are candidates for connection to the GCD and in most cases, should be connected to a GCD. Determination of the specific fixtures and drains that must connect to a GCD is based primarily on the potential for FOG‐laden wastewater to be encountered at each fixture/drain. Some sinks/drains present less risk for FOG laden wastewater and present less risk if not connected to the GCD. Table 2.1 below provides a summary of the typical FSE fixtures/drains and their associated potential for FOG‐laden wastewater discharge:

Table 2.1 – Fixture and Drain Connections to a GCD

Fixture Location Potential for FOG Connection to GCD

Multi‐Compartment/ Scullery Sink

Dish Wash, Food Prep, Cooking Areas

High Recommended

Pot/Pan Wash Sink Dish Wash, Food Prep, Cooking Areas

High Recommended

Pre‐Rinse Sink (for dishwashing)

Dish Wash Area High Recommended

Floor Drain/Trench Drain Cooking Area (for Kettles or other Equip)

High Recommended

Floor Sinks (with equipment drains)

Cooking Area (for Wok Ranges, Hoods Drains, other Equipment)

High Recommended

Floor Sinks/Floor Drains/Trench Drains

Dish Wash Area Moderate Recommended

Mop Sink Dish Wash, Food Prep, Cooking Areas

Moderate Recommended

Floor Drains Food Prep, Cooking Area Moderate Recommended

Commercial Dishwasher (without a pre‐rinse sink)

Dish Wash Area Moderate Recommended

Prep‐Sinks (General) Food Prep, Cooking Area Moderate or Low Optional

Floor Sinks (no equipment drains)

Food Prep, Cooking Area low Optional

Prep‐Sink (Vegetable Prep Only)

Food Prep Area Low Optional

Commercial Dishwasher (with a pre‐rinse sink)

Dish Wash Area Low Not Necessary

Commercial Dishwasher Beverage, Bar Area Low Not Necessary

Hand Sinks Any Low Not necessary

Floor Sinks (for Bev/Ice Machines)

Any Low Not necessary

Toilets and Hand Sinks Restrooms N/A Never



Multi‐Compartment/Scullery Sinks Multi‐compartment sinks, most frequently 3‐compartments, are typically the most used sink in the food service establishment. This sink is used for a variety of functions including dish washing (in lieu of an automatic dishwasher), utensil washing, and pot/pan washing. Additionally, multi‐compartment sinks are sometimes used for pre‐rinsing of dishes prior to insertion into an automatic dishwasher/sanitizer. Due to its extensive uses, this sink has a high potential for FOG laden wastewater and connection to the facility’s GCD should be required.

Potential Exceptions: Some FSEs have multi‐compartment sinks in beverage or bar areas, used primarily for glass ware washing. In this type of location, these sinks present a very low potential for FOG‐laden wastewater and connection to a GCD is not necessary.

Pot/Pan Wash Sinks Many FSEs have a sink designated for washing/rinsing cooking residue from pots and pans. Such a sink has a high potential for FOG laden wastewater connection to the facility’s GCD should be required.

Potential Exceptions: Rare Dishwasher Pre‐Rinse Sinks Some FSEs with a commercial dishwasher have a sink designated for pre‐rinsing of dishes, utensils, trays, pots, and pans prior to processing through the dishwasher. Because this sink will be routinely exposed to food scraps and residue, there is a high potential for FOG laden wastewater from this sink. Connection of this sink to the facility’s GCD should be required.

Potential Exceptions: Rare Floor Drain/Trench Drains (food cook areas) FSEs may have floor or trench drains near cooking equipment such as tilt kettles or tilt skillets. Such drains are designed to facilitate cleaning/rinsing of the large cooking equipment, which can contain significant amounts of food residue. This drain has a high potential for FOG laden wastewater and connection to the facility’s GCD should be required.

Potential Exceptions: If the drain is designated to receive the water from steam tables, connection to the GCD may not be necessary as there is little potential for FOG laden wastewater to be encountered.

Floor Sinks (with equipment drains in food cooking areas) Floor sinks in food cooking areas are often designated to receive the drainage or runoff from cooking equipment such as wok ranges, char‐broilers, and exhaust hoods. This equipment can discharge significant amounts of FOG‐laden waste and connection to the facility’s GCD should be required.

Potential Exceptions: Rare Floor Sinks/Floor Drains/Trench Drains (Dish wash areas) Floor sinks, floor drains and/or trench drains in dish wash areas are frequently exposed to the drainage or spills from dish washing activities, which can include food waste from dishes or pots/pans. Additionally, spills in these areas are likely to be directed to the area drains rather than cleaned up with absorbents. Therefore, these drains have a moderate potential for FOG laden wastewater and where practicable, connection to the facility’s GCD should be required.

Potential Exceptions: Rare



Mop Sink (located in dish wash, food prep/cooking areas) Mop sinks receive water from routine floor cleaning/disinfecting activities as well as from the clean‐up of accidental spills. Since is not uncommon for grease and oils that are spilled or spattered onto the floor to be tracked across the floor by kitchen personnel, there is a moderate potential for FOG laden wastewater to be dumped into this sink. Therefore, where practicable, connection to the facility’s GCD should be required.

Potential Exceptions: For some facilities, the mop sink may be located in a remote janitor/utility closet, where it may not be practicable to gravity flow the drain to the GCD. In such cases, connection directly to the sanitary sewer can be considered.

Floor Drains (in food prep/cooking areas) Floor drains in food preparation and cooking areas often receive water from floor cleaning activities as well as from the clean‐up of accidental spills. Therefore, these drains have a moderate potential for FOG‐laden wastewater and where practicable, connection to the facility’s GCD should be required.

Potential Exceptions: Rare Prep‐Sinks (Food prep, cooking areas) Prep sinks are intended for washing fruits and vegetables. Depending on their physical location in the kitchen area, they can be used for other purposes such as dish or pot/pan washing. The potential for FOG‐laden wastewater from this sink can be moderate and connection to the facility’s GCD should be required.

Potential Exceptions: Where it is clear that the prep sink will be used for vegetable prep only (BMPs in place to reinforce its use), connection to the GCD may not be necessary.

Floor Sinks (no equipment drains in food prep/cooking areas) Floor sinks with no equipment drains (unused) are not likely to receive much wastewater drainage. If the floor sink rim is set above the floor, there is minimal potential for wash water from floor clean‐up activities to be directed to the floor sink. Therefore such a sink presents a low potential for FOG‐laden wastewater and connection to a GCD may not be necessary.

Potential Exceptions: Rare Commercial Dishwasher (with a pre‐rinse sink) Commercial dishwashers in FSEs with a pre‐rinse sink, are generally used for sanitizing purposes. The vast majority of residual food waste (and corresponding FOG) are washed away during the pre‐rinse process. There can be some residual food/FOG material on the dishes placed in the dishwasher, and the high temperature water from a dishwasher can be beneficial to the FOG separation process; however, emulsification from dishwasher detergents can negatively impact the FOG separation process and contribute to FOG pass‐through. Since the potential for FOG‐laden wastewater from a dishwasher (with a pre‐rinse sink) is typically low, and there is some potential for the dishwasher discharge to negatively impact GCD performance, connection to the GCD is not recommended.

Potential Exceptions: If there is no pre‐rinse of wares prior to the dishwasher, there is then a high likelihood of significant FOG‐laden wastewater from the dishwasher process. In these cases, connection to a GCD should be required. A GGI is suitable to receive the dishwasher discharge; however, a HGI is not. Therefore, a facility needing a GCD that utilizes a commercial dishwasher but has no pre‐rinse sink, must use a GGI. It is also important that GGI sizing account for the discharge flow rate from the connected dishwasher machine (refer to sections 3 and 4 below).



3.0 FIXTUREUNITVALUEDETERMINATION Once fixtures and drains have been designated for connection to the GCD, the Drainage Fixture Unit (DFU) value for each will be needed to determine interceptor sizing. DFU determination is based primarily on the fixture drain line or trap size as follows:

Table 3.1 – Fixture/Drain DFUs

Drain/Trap Size (inch)

Fixture Unit Equivalent(DFUs)

1‐¼ 1

1‐½ 3

2 4

3 6

4 8

>4 Consult with City

Exceptions/Special Circumstances:

Emergency floor drains, regardless of their size, can be assigned a DFU value of 0 (zero) as they are not intended to receive water flow on a regular basis and should not factor into GCD sizing.

For multi‐compartment sinks with individual drain lines for each compartment, DFUs should be determined for each drain individually. Where compartment drains are combined, the DFU value shall be determined based on the shared drain line size.

Fixture unit values of floor sinks receiving drainage from other fixtures/equipment (e.g., indirect drainage from a prep sink) shall be determined by:

o Combining the fixture DFU values for each of the fixtures received, or o Using the drain/trap size of the floor sink o NOT both.

Fixture unit equivalents for equipment with continuous drainage (e.g., wok range), shall be assigned 2 DFU for each gallon per minute (GPM) of rated flow.

Fixture unit equivalents for equipment with intermittent drainage (e.g., commercial dishwasher), shall be assigned fixture unit values per UPC Table 702.2(b) as follows:

Table 3.2 –Fixture Unit Equivalents (for Intermittent Flow Only)

GPM Fixture Unit

Up to 7 ½ 1

Greater than 7 ½ to 15 2

Greater than 15 to 30 4

Greater that 30‐50 6

Greater than 50 Consult with City



DFU values typical of common FSE fixtures and drains are summarized in the table 3.2 below.

Table 3.3 – Common Fixture/Drain DFU Values

Fixture Connection to GCD

DFU Value

3‐Compartment Sink Required 4

Pot/Pan Wash Sink Required 4

Dishwasher Pre‐Rinse Sink Required 4

Trench Drain Required 3

(per trench outflow)

Floor Sinks (Indirect sink drains)

Required 4

(or sum of indirect sink drain DFU values)

Floor Sinks (with equipment drains)

Required 4

(or equipment discharge flow rates)

Floor Sinks/Floor Drains/Trench Drains

Required 4

Mop Sink Required 3

Commercial Dishwasher (without a pre‐rinse sink)

Required 8

(or equipment Discharge flow rates)

Floor Drains (emergency) Required 0

Prep‐Sinks (General)

Optional 3

Floor Sinks (no equipment drains)

Optional 1

Prep‐Sink (Vegetable Prep Only)

Optional 3

Commercial Dishwasher (with a pre‐rinse sink)

Not necessary 8

(or equipment Discharge flow rates)

Hand Sinks Not necessary 2

Floor Sinks (for Bev/Ice Machines)

Not necessary 3



4.0 GGISIZING When the DFU values of the fixtures and drains connected to a GGI are known, the minimum volume of the GGI shall be determined by Table 4.1 (pursuant to UPC 1014.3.6) as follows:

Table 4.1 – GGI Sizing (DFU Based)

Drainage Fixture Units(DFUs)

Minimum Interceptor Volume (Gallons)

21 750

35 1000

90 1250

172 1500

216 2000

>216 Consult with City

When the DFU values are not known, the minimum GGI size can be determined based on the maximum DFUs allowed for the grease waste pipe size connected to the inlet of the GGI as follows:

Table 4.2 – GGI Sizing (Pipe Size Based)

Pipe Size (Inch)

Maximum DFUs Minimum Interceptor Volume (Gallons)

3 35 1000

4 172 1500

4 216 2000

>4 >216 Consult with City

Note: Where the flow rate of directly connected fixtures or appliances have no assigned DFU values, the additional grease interceptor volume shall be based on the known flow rate multiplied by 30 minutes. 5.0 HGISIZING Hydromechanical Grease Interceptors (HGI) are equipped with a flow control device that limits the flow of wastewater into and through the HGI. Flow control devices are designed and installed so that the total flow through the device is not greater than the rated flow of the connected HGI. Because of this flow limiting functionality, HGI sizing can vary depending on the fixture drainage period that is tolerable to the FSE (or required by the City). Drainage periods typically considered in HGI sizing are one‐minute and two‐minute. A longer drainage period allows for a smaller HGI size. Most agencies that allow installation of HGI devices leave it to the FSE’s discretion to select the drainage period. Given a defined drainage period, HGI sizing can be determined through one of the following two methods (reference UPC 1014.2):



1. HGI Sizing Using Gravity Flow Rates This method considers the maximum flow a pipe can convey under gravity flow conditions in determining the appropriate HGI size. In the table below, full pipe flow for various pipe sizes is calculated using Manning formula (assumes ¼ inch/foot slope and a friction factor of N=0.012). The minimum HGI size is defined based on the full pipe flow rates corresponding to the grease waste pipe size. These values are summarized as follows:

Table 5.1 – HGI Sizing (Flow Rates)

Diameter of Grease Waste Pipe (inches)

Full Pipe Flow1 (gpm)

HGI Size

One‐MinuteDrainage Period

(GPM)

Two‐MinuteDrainage Period

(GPM)

2 20 20 10

3 60 75 35

4 125 150 75

5 230 250 125

6 375 500 250 1 Assumes slope of ¼‐Inch per foot, using Manning’s formula with N=0.012

2. HGI Sizing Using Fixture Capacity

This method considers the capacities (volumes) of the fixtures discharging to the HGI device in determining the appropriate HGI size. The following steps are used to determine fixture capacities and the corresponding HGI size using this method. Step 1 – Calculate Fixture Capacities

Sinks/basins = Length x Width x Depth x 0.75 (fill factor); or Rated Appliance = Specified flow rate

Step 2 – Calculate total wastewater load (sum of capacities) Step 3 – Determine HGI size based on total wastewater load An example of this method is provided in Table 5.2 below:

Table 5.2 – HGI Sizing Example (Fixture Capacity)

Fixtures Compartment Size/Flow Rate

Qty Wastewater

Load (Gallons)

HGI Size

One‐Minute Drainage Period (GPM)

Two‐MinuteDrainage Period (GPM)

3‐comp Sink 24in x 24in x 12in 3 67.3

1‐comp Sink 24in x 24in x 12in 1 22.4

Hood Wash 4 GPM 1 4

Total 93.7 100 50

In the above example, a 50 GPM to 100 GPM HGI would be acceptable, depending on the desired (or required) drainage period.



With either of the two sizing methods, the total capacity (in gallons) of the fixtures discharging into the HGI cannot exceed two and one‐half times the certified flow rate of the HGI. This will impose a limitation on the total number of fixtures that can be connected to an individual HGI. Note: A HGI is not appropriate for use in a facility with a commercial dishwasher without a pre‐rinse sink. Pursuant to UPC 1014.2, the vent or air inlet of the flow control device shall connect to the sanitary drainage vent system or through the roof of the building, and shall not terminate to the free atmosphere inside the building. 6.0 HGITYPES Pursuant to UPC section 210.0, HGI is defined as follows: A Plumbing appurtenance or appliance that is installed in a sanitary drainage system to intercept non‐petroleum fats, oil and grease (FOG) from a wastewater discharge and is identified by flow rate, and separation and retention efficiency. The design incorporates air entrainment, hydromechanical separation, interior baffling, or barriers in combination or separately, and one of the following:

A – External flow control, with air intake (vent), directly connected. B – External flow control, without air intake (vent), directly connected. C – Without external flow control, directly connected. D – Without external flow control, indirectly connected.

While there is a wide variety of manufactures and configurations of HGI devices, operationally, there are two general categories:

“Passive” HGIs, which simply trap and retain separated FOG.

Grease Removal Devices (GRD), which automatically remove the separated FOG from the HGI, typically into a separate holding container.

Both categories have similarities that include:

When properly sized, installed and maintained, both can be effective in removing FOG from the wastewater discharged to them.

Sized pursuant to UPC Section 1014.2.

Typically installed indoors but can be installed outdoors.

Construction materials include metal, fiberglass, or plastic.

If compliant with UPC, been certified by an accredited conformity assessment body (listing agency), indicating that the device has been certified to its listed flow rate and grease retention capacity, pursuant to applicable standards (e.g., ASME A112.14.3‐2000 and ASME A112.14.4‐2001).

Require internal or external flow control devices, some with (others without) air intake (vent).

Require access to external flow control devices for maintenance, particularly when installed below ground.



Require routine maintenance (removal of accumulated FOG/solids) to ensure device performance.

Common sizes range from 15 GPM to 150 GPM (and higher). While both categories are HGIs, there are some differences that will factor into their applicability in certain situations. Key differences include:

The automated functionality of a GRD can help simplify the level and frequency of maintenance interaction by FSE personnel; however, GRDs also introduce an added level of maintenance complexity with electrical timers, heaters, scrapers, motors, etc., all of which must be properly set‐up and maintained to provide the automated functionality.

Passive HGIs are well suited for sub‐slab installation (vaulted). When covers are properly installed and attached, they are generally sealed and are not susceptible to leaking in the event of a downstream blockage.

GRDs are not well suited for sub‐slab installation. Even with all covers properly installed, GRDs are not sealed and a downstream blockage can result in spillage from the unit. Additionally, a key feature of a GRD is the visual indication of FOG levels in collection containers. When installed sub‐slab, this visual indication is likely lost.

7.0 GGIVS.HGI As discussed above, Most types of GCDs can be effective in reducing FOG discharges to the sewer if:

The fixtures and drains with FOG‐laden wastewater are connected to the device

The device is properly sized for the connected fixtures/drains

The device is properly installed and maintained Historically, GGIs have been the grease control technology of choice for FOG Control programs across the country. Because of their larger size and typical underground installation, GGIs are well suited to receive the drainage from all grease bearing fixtures/drains in the FSE, including floor mounted sinks and drains. GGIs require routine maintenance, which typically consists of pumping/hauling the accumulated FOG and solids (and water) for off‐site disposal every 2‐4 months. This maintenance service is not typically performed by the FSE personnel so reliance on the FSE to ensure proper operation of a GGI is limited to arranging the service (scheduling and paying). Additionally, because GGIs are typically located outside the FSE, they are readily available for inspection by regulatory personnel to assess the maintenance condition. The downside of GGIs is that they require significant space, can be costly to install (particularly in a retrofit situation), and can contribute to sewer system odor and corrosion issues (particularly when oversized). For these reasons, HGIs are often considered as an alternative to a GGI in certain situations. HGIs are smaller devices that may be installed above or below ground, as well as outside or inside of a food facility. Because of their smaller size, HGIs tend to be less expensive for the FSE to install; however, multiple devices may be needed to capture the flow from all appropriate fixtures and drains, which increases installation/maintenance costs. Additionally the smaller device size results in a need for more frequent service and maintenance (weekly to monthly) to ensure the proper operation of the device(s). This frequent maintenance is often self‐performed



by the FSE, thereby increasing the reliance on FSE personnel and FSE practices to ensure device performance. Because the frequent maintenance of HGIs is critical to their performance, increased regulatory oversight (i.e., inspection) is often implemented for facilities with these devices. The City requires FSEs to install a GCD for all potential FOG‐bearing fixtures and drains in the FSE’s food preparation and clean‐up areas. GGIs are generally the preferred GCD technology for FOG source control, particularly when the FSE is associated with new construction. For existing FSEs required to install a GCD (typically triggered by the permitting process for remodels or other changes in operations), the City considers both GGIs and HGIs as suitable GCD options, as long as all of the required fixtures and drains are connected to the GCD. Several key factors are considered in determining the appropriate GCD configuration for each FSE. These primary factors include:

Scope of construction activities

The risk of the facility to discharge FOG to the sewer system

Physical site limitations of the FSE/property Scope of Construction Activities Installation of a GCD and its associated piping is an intrusive activity, best suited to be conducted during other facility construction activities. For existing operational FSEs, a GCD retrofit can require significant operational downtime, resulting in business losses in addition to the installation costs. These potential impacts to the FSE should be considered in determination of GCD requirements for FSEs in GCD retrofit situations. Risk of Facility to Discharge FOG Generally, the risk of a facility to discharge FOG should be evaluated based on the type of cooking equipment and/or processes employed by the FSE. This approach helps to eliminate the consideration of the food types being cooked (which can change at any time without notification to the City) as a factor in determining FOG‐risk. If the facility uses equipment with a high risk for generating FOG (e.g., deep fryers, griddles, stoves, woks, tilt skillets, char broilers, etc.), or employs practices with a high risk for discharging FOG (e.g., reusable dishes requiring dishwashing), the FSE is considered a High FOG Risk facility and GCD requirements should be applied accordingly. Physical Site Limitations Space constraints and the depth of the existing sewer can limit the CGD options that a facility can feasibly implement. There are situations where there is simply no physical space for a GGI. In some cases, there may be a space available for a GGI; however there is no feasible way to access that space for connection from the FSE or maintenance of the GGI (e.g., underground parking structure). Similarly, the existing sewer line that will receive the effluent from the GCD must be sufficiently deep to accommodate the appropriate pipeline slope to ensure proper gravity flow. Figure 7.1 – GCD Requirements Guideline, provides a decision process that considers these factors for a fair and equitable determination of appropriate CGD configurations. In considering this process, Table 7.1 summarizes applicable GCD configurations for New FSEs (new construction), and Table 7.2 summarized applicable GCD configurations for Existing FSEs.



Table 7.1 ‐ Applicable GCD Configurations For New FSEs

(New Construction)

High FOG‐Risk Equipment/Practices

Sufficient Space/Slope

Acceptable GCD Configuration

Yes Yes GGI (for all potential FOG‐bearing fixtures/drains)

No NA Provide for future GGI or HGI Installation

Table 7.2 ‐ Applicable GCD Configurations For Existing FSEs

(Remodel, Change in Operations/Ownership)

High FOG‐Risk Equipment/Practices

Sufficient Space/Slope

Acceptable GCD Configuration

Yes Yes GGI or HGI (for all potential FOG‐bearing fixtures/drains)

Yes No HGI (for all potential FOG‐bearing fixtures/drains)

No NA GCD Installation not required



Documents

Grease Interceptor Sizing Using UPC - City of MilpitasGrease Interceptor Sizing Using UPC – Draft-Final June 6, 2017 W‐2978 City of San José 3 EEC 2.0 FIXTURE AND DRAIN CONNECTIONS