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FOG Light™

FOG Light™

21st Century FOG management

Many jurisdictions are still working from code language written 40 years ago. Much has changed in how we understand materials, flow patterns, sizing and more.

As your partner in the pretreatment community, Schier is committed to providing code officials with best-in-class grease interceptor products along with updated research, education and resources to help in developing or amending FOG (fats, oils and grease) discharge management programs. FOG Light™ by Schier is your go-to resource in the treatment of kitchen wastewater - serving as a beacon to guide you in code and program decisions, with a focus on right sizing and corrosion-resistant products.

Our goal is to help wastewater authorities prevent, reduce, or eliminate the costs and impacts of FOG discharges on sewer collection systems.

Three pillars of

A Holistic FOG Program

Corrosion resistant grease interceptors

3rd-party certified performance testing

Right sizing for optimal pumpout frequency


# 1

Corrosion Resistance

Animal fats, dairy, sugars, salts and all other food waste will decay overtime inside of a grease interceptor. These food particles create hydrogen sulfide gas, which eats away at steel and concrete grease interceptors from the inside out. The average lifespan of a steel grease interceptor is 5 years and the average lifespan of a concrete grease interceptor is 10 years. The solution is mandating only non-corrosive materials such as polyethylene.

The Water Environmental Research Foundation's 2008 report on fats, roots, oils and grease shows that FOG deposits found in collection systems were made up of calcium and iron from hard water, concrete and steel corrosion. Inadequate construction practices, such as insufficient concrete cover for reinforcement, improper curing, or poor concrete quality, can lead to increased vulnerability to corrosion as well.

Learn more

# 2

Performance Testing

Schier first innovated diffusion flow grease separation in 2005, and we've spent years since honing the inner workings of grease interceptors to optimal performance. What we know to be true, is that a laminar, turbulent-free environment promotes significantly more efficient separation of FOG. Schier's design includes inlet and outlet diffusers, along with baffles for our larger units, and allows an interceptor to achieve more than 90% efficiency.

Gravity grease interceptors that are listed to Z1001, on the other hand, are only constructed to meet design criteria and structural analysis, not performance. No testing is performed on these units to ensure proper function. When modeling and testing was performed on gravity units by WERF, it was found that the turbulent environment led to bypass and poor efficiency.

In-house testing and third-party certification

We believe performance test reports should be transparent and posted publicly from all manufacturers. Testing and certification is at the heart of right sizing. We invite IAPMO to certify each Schier unit on our state-of-the-art, in-house test lab, bringing objectivity, expertise, credibility and risk mitigation to the evaluation of performance. The results show how well the unit works at a specified flow rate and exactly how much grease it will store. These reports allow YOU to compare the performance of the system against industry standards and other manufacturers.


# 3

Right Sizing

All grease interceptors have a maximum grease holding capacity, whether tested and rated or not. When that capacity is exceeded, an interceptor will bypass grease into the collection system. It is critical that grease interceptors be maintained as they become full and not allowed to fill beyond that point. This is accomplished by using right sizing calculations. Many jurisdictions across the country use the 25% rule. This rule, while applied to untested gravity interceptors, is not appropriate for hydromechanical interceptors because of advancements in design. HGIs have substantially larger storage capacities making the 25% rule irrelevant.

Grease Production Sizing Method (GPSM), introduced by Schier in 2012, calculates how much grease a restaurant is likely to produce to ensure the grease interceptor has enough capacity to allow for a realistic and affordable pumpout frequency. GPSM has been used to size more than 100,000 restaurant grease interceptors, adopted by several municipalities, published in the 2016 edition of the ASPE Plumbing Engineering Design Handbook, and powers our Grease Monkey ® sizing app.

We're here

Every step of the way

Code Writing

Whether you're developing or revising code, our experts can consult on every aspect of FOG regulation.

Plans Review

When specifiers opt in for sizing pre-approval, our specialists confirm and ensure code compliance.


Schier grease interceptors are designed for easy and proper installation, so that inspections run smooth.

Meet our

Regulatory Compliance Team


Eric Thompson

Regulatory Compliance Manager


Gonzalo Lagos

Regulatory Compliance Manager


Andy Carbajo

Regulatory Compliance Specialist


Tye Cooley

Regulatory Compliance Specialist


Troy Duvanel

Regulatory Compliance Specialist

Schedule a consultation

Blogs for you


The evolution of flow control devices

Hydromechanical grease interceptors (HGI) typically require a flow control device to restrict the incoming flow to the flow rate to which the grease interceptor is certified. These devices haven’t always been used the way they are today.

Read Blog


Understanding cover load ratings

The American Association of State Highway and Transportation Officials (AASHTO) has implemented weight restrictions governing manhole covers within the United States.

Read blog

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