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Hydromechanical Grease Interceptor

Gravity Grease Interceptor


Online: $22,717.10

List: $32,453.00

Buy Now

100 GPM / 10,061 lbs
200 GPM / 9,446 lbs

Indoor / Outdoor

1,588 GAL

Liquid Capacity

Product Description

100/200 GPM Hydromechanical/Gravity Grease Interceptor

The GB-1500 consists of three independent rotationally molded halves bolted and welded together to create two baffle walls and provide tremendous structural integrity. It can be installed above grade (on the ground) or buried below grade (compatible with FCR2 risers to bring system to grade), as well as indoor or outdoor.

More Features:

  • Rugged polyethylene tank body

  • 20% kitchen solids waste capacity

  • No flow control required, first in the industry certified to Type D of the ASME standard

  • Safety Star® access restrictor prevents accidental entry

  • Preinstalled pumpout port option available

  • Contains baffle walls

  • Three manholes for increase visibility into chambers

Listed by IAPMO to ASME A112.14.3/CSA B481.1-2022 (Type D)
Listed by IAPMO to ANSI/CAN/IAPMO Z1001-2021

Miami DERM

Meets 99% efficiency requirement for Miami DERM:

  • 100 GPM (6.3 L/s) / 9,897 lbs. (4,489 kg)

  • 200 GPM (12.6 L/s) / 8,093 lbs (2,540 kg)

Need Documentation?

Technical Information

Flow Rate/Grease Capacity
100 GPM (6.3 L/s) / 10,061 lbs (4,562.8 kg)
200 GPM (12.6 L/s) / 9,446 lbs (4,283.9 kg)

Solids Capacity 318 gal (1203.8 L)

Liquid Capacity 1,588 gal (6,011.2 L)

Weight 1,290 lbs (585 kg)

Installation Location Indoor/Outdoor

GB-1500 product image
Is the GB-1500 the 'right-sized' model for you?

on-grade perfection

Schier's cover adapters give 4" of vertical adjustability and up to a 5-degree tilt in any direction, helping to ensure covers are installed perfectly inline on the concrete pad.



Schier's FCR2 field cut risers are designed for easy modification in the field to reduce jobsite installation time and eliminate custom riser costs.

If using 24" corrugated risers (by others), you will need the CA2 riser adapters. You will not use a CA2 with an FCR2.


See our test lab

The GB-1500 is performance tested in house and third-party certified

On the tank

Product ID label with technical and certification details (also available inside the cover adapter)

"Made By" label featuring one of our product builders and the date your interceptor was built


The GB-1500 is built with two baffle walls that aid our flow diffusers with high-performance grease separation as the contents move through the tank from one chamber to the next. All Schier Great Basin™ grease interceptors are designed to slow turbulent flow, allowing increased separation performance and up to 99% grease-free output.


FCR2 product image
Field cut riser
AK3 product image
Anti-flotation anchor kit for use with GB-1000, GB-1500 and all Big Foot® models.
ATD1 product image
For securing covers to units in ABOVE GRADE INSTALLATIONS with increased head pressure conditions.
CA2 product image
Adapter for 24" Corrugated Pipe Riser
CC2 product image
For recessed and suspended units with 24" covers.
PLAIN-EA-24 product image
4" MPT - 2" Plain End Fitting.
PLAIN-EA-34 product image
4" MPT - 3" Plain End Fitting.
FPT-EA-23 product image
3" MPT - 2" FPT Fitting.
FPT-EA-34 product image
4" MPT - 3" FPT Fitting.

Frequently Asked Questions

Are the Great Basin® indoor/outdoor units traffic rated (H-20 load rate)?

These units are traffic rated if they are installed in accordance with our installation instructions. The unit will need the H-20 load-rated cast iron covers and a traffic-rated pad at grade per our installation detail.

Can corrugated pipe be used as a riser on the Great Basin® indoor/outdoor units?

A 24" double wall corrugated pipe can be used as a riser for these units. You will need to purchase Schier's adapter for 24" corrugated pipe riser (CA2).

Can the discharge from a food waste grinder be run through the Great Basin® indoor/outdoor units?

These units have solids capacity of 20% or more of the unit's liquid volume, but food waste grinders can quickly overwhelm a grease interceptor. If the food waste grinder is connected to the unit, we recommend a solids interceptor in front of the grease interceptor.

Can the Great Basin® indoor/outdoor units be installed above grade (on the ground)?

All Great Basin® indoor/outdoor models can be installed above grade. The the adapter tie down kit (ATD1) is recommended to ensure the adapters do not become unseated in the event of a downstream backup. A GB-500 installed above grade must also have the above grade support kit (AGS2).

Can the Great Basin® units be used with a dishwasher?

These units can be used with a dishwasher. If the dishwasher will have a discharge temperature higher than 150 degrees Fahrenheit, the system will require a drain tempering valve to reduce the water temperature.

Can you suspend the Great Basin™ indoor/outdoor units from the ceiling above?

These units can be suspended from above (with the exception of GB-1000 and GB-1500). The unit needs to be fully supported across the bottom with risers extending to the floor above. It is the responsibility of the specifying engineer or installer to design a support system appropriate for the weight of the unit with water. If suspending a GB-250, the unit must be installed with the above grade support kit (AGS1). If suspending a GB-500, the unit must be installed with the above grade support kit (AGS2).

Do the Great Basin™ indoor/outdoor units need to be installed inside a vault to be buried in a high-water table area?

If the units will be installed in an area where the water table will crest the inlet/outlet pipe, additional steps need to be taken to protect the unit from the extreme hydrostatic forces. The unit would need to be placed in a water tight vault or encased in concrete. If there is a possibility that ground water will come into contact with the unit, there needs to be a high-water/anti-flotation anchor kit installed (AK1, AK2, AK3).

Do the Great Basin® units require a fixture vent?

These units do not require a fixture vent. The internal design of the unit will ensure proper function without a fixture vent. Any venting to the piping connected to our unit is at the discretion of the local authority.

How many risers can be installed with a Great Basin® indoor/outdoor unit?

The maximum number of risers that can be used with a buried indoor/outdoor unit is three per manhole. If the unit is suspended with risers to the floor above, they can use more than three if needed.

Our fixture has an air gap and discharges into a floor sink, which is overflowing. How can we fix this?

Due to the low head pressure in this scenario, the first solution is to remove the internal flow control. This low head pressure ensures the unit will not exceed its certified flow rate. If that doesn’t solve the issue, the next solution is to add a flow restrictor to the tailpiece of the fixture.

What are the minimum and maximum riser heights of buried Great Basin™ indoor/outdoor units?

The adjustable adapters that ship with these units offer up to 4" of built-in riser height. The maximum height for field cut risers is 94," which is equivalent to three FCR2 risers (sold separately). If the unit is suspended with risers to the floor above, they can use more than three if needed.

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