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Presented by Rand Ackroyd

Plumbing and Drainage Institute• The Plumbing and Drainage Institute

(PDI) was formed in 1949.

• The organization developed the original performance requirements for Grease Interceptors (Hydromechanical Grease Interceptors) PDI G101.

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Our objectives:

– Advancement of Engineered Plumbing Products

– Publicity/Public Relations

– Research

– Publish Standards

– Education

Plumbing and Drainage Institute

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GREASE…

How Bad Can It Be?

• Myth:Myth: If grease is not used in food If grease is not used in food

preparation a grease interceptor is not preparation a grease interceptor is not needed.needed.

• Fact:Fact: Grease is not the only problem. The Grease is not the only problem. The overall problem is FOG (Fats, Oils and overall problem is FOG (Fats, Oils and Grease). These materials alone or in Grease). These materials alone or in combination will result is sewer blockages.combination will result is sewer blockages.

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• Myth:Myth: Choosing a larger size grease Choosing a larger size grease

interceptor will result in a greater grease interceptor will result in a greater grease removal efficient.removal efficient.

• Fact:Fact: When grease interceptor has been When grease interceptor has been sized properly to the anticipated maximum sized properly to the anticipated maximum flow using a grease interceptor with a larger flow using a grease interceptor with a larger flow capacity will not increase grease flow capacity will not increase grease removal efficiency.removal efficiency.

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• Myth:Myth: The larger the grease storage, the The larger the grease storage, the

more efficient the interceptor.more efficient the interceptor.

• Fact:Fact: Grease must be separated from the Grease must be separated from the waste water before it can be stored. waste water before it can be stored. Storage capacity and grease removal Storage capacity and grease removal efficiency are not related.efficiency are not related.

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• Myth: Myth: The grease must cool and harden to The grease must cool and harden to separate from the waste water.separate from the waste water.

• Fact: Fact: Grease interceptors separate based on Grease interceptors separate based on the difference in specific gravity of FOG and the difference in specific gravity of FOG and water. Liquefied grease floats just as well as water. Liquefied grease floats just as well as solidified grease. Grease is lighter than solidified grease. Grease is lighter than water.water.

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• Myth:Myth: Hot water will melt the grease and Hot water will melt the grease and wash the grease through the interceptor.wash the grease through the interceptor.

• Fact:Fact: All hydro mechanical grease All hydro mechanical grease interceptors are tested for grease removal interceptors are tested for grease removal efficiency with 150°F water.efficiency with 150°F water.

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• Myth:Myth: Once the grease is captured in the Once the grease is captured in the interceptor, it will remain captured in the interceptor, it will remain captured in the interceptor as long as the interceptor is not interceptor as long as the interceptor is not yet 25% full.yet 25% full.

• Fact:Fact: Because the grease (FOG) is Because the grease (FOG) is contaminated with food particles and the contaminated with food particles and the interceptor is a breeding ground for bacteria, interceptor is a breeding ground for bacteria, the FOG can be broken down, exit the the FOG can be broken down, exit the interceptor and create blockages interceptor and create blockages downstream. downstream.

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• Myth:Myth: Over sizing an interceptor cannot Over sizing an interceptor cannot hurt.hurt.

• Fact:Fact: Over sizing an interceptor relative to Over sizing an interceptor relative to actual flow actual flow is a problemis a problem. It can result in the . It can result in the generation of hydrogen sulfide gas that can generation of hydrogen sulfide gas that can convert to hydrochloric acid. Both metal convert to hydrochloric acid. Both metal and concrete structures downstream have and concrete structures downstream have suffered severe structural damage from suffered severe structural damage from this acid.this acid.

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• Myth:Myth: With the change to healthier cooking With the change to healthier cooking oils, there is less of a FOG problem.oils, there is less of a FOG problem.

• Fact:Fact: Cooking oils that are healthier for you Cooking oils that are healthier for you are not healthier for the drainage system. are not healthier for the drainage system. They are all polar hydrocarbons. In fact, They are all polar hydrocarbons. In fact, some of the new alternative cooking oils some of the new alternative cooking oils with specific gravities closer to water will with specific gravities closer to water will be harder to capture from the wastewater.be harder to capture from the wastewater.

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• Myth:Myth: When the grease interceptor is full, When the grease interceptor is full, the drain line will stop flowing.the drain line will stop flowing.

• Fact:Fact: Water will continue to flow even when Water will continue to flow even when the FOG in the interceptor is at capacity. the FOG in the interceptor is at capacity. Additional grease in the wastewater will Additional grease in the wastewater will simply flow right through the interceptor. simply flow right through the interceptor. Grease interceptors must be either Grease interceptors must be either manually or electronically monitored.manually or electronically monitored.

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• Myth:Myth: Grease does not clog plastic pipe Grease does not clog plastic pipe

• Fact:Fact: Grease can create blockages all al Grease can create blockages all al drain pipe materials.drain pipe materials.

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Thank You For Your Time!