FOG Pretreatment

In 1969, the Cuyahoga River in Ohio caught fire.

The blaze caught the attention of the national media, and Time magazine described the Cuyahoga as a river that “oozes,” rather than flows. There were no fish or other animals in the water, and the concentration of oil and other toxins was so thick that they could actually burn.

The river had become, in effect, a giant grease trap.

And the ’69 fire was not event the first time the river had caught fire, and it by Cuyahoga standards, it was relatively mild. Dating back to the 1860s, the river had caught on fire at least 13 times. In 1952, the largest such fire caused more than $1 million of damage to boats, docks and a riverfront building. But the 1969 fire had a major impact on efforts to clean up the nation's waterways.

The damage that grease and other pollutants can inflict on the environment is well documented, but few cases illustrate this as well as Narragansett Bay in Rhode Island.

Narragansett Bay is a prime example of what untreated sewage can do to the environment. However, it’s also a great case study in how pretreatment can help turn around polluted waterways and help reverse the impact of pollution.

The problem began in the 18th century when Rhode Islanders would empty their raw sewage directly into their nearby rivers that flowed into the bay. By the 1970s, nearly 65 million gallons of untreated sewage was flowing into Rhode Island’s waters each day. Grease deposits the size of soccer balls were sometimes seen floating in the bay. The bay’s shellfish beds, which had created a booming industry, were closed.

If you live in a rural area, chances are good that you use a septic system to treat your wastewater. If that’s the case, you’re probably careful about what goes down the drain and into the tank. You might, for example, pour any used cooking oil or grease into a disposable container and toss it into the garbage can. Sound familiar?

Though that might be standard practice for residences with on-site sewage management, it’s not exactly a feasible option for commercial entities that produce a high volume of grease, such as restaurants and resorts. To maintain an effective sewage treatment system free of grease clogs, pretreatment is vital.

Keeping grease out of your local sewage system — whether it's a septic field or another treatment process — will save you money and prevent maintenance headaches in the future.

A packed-to-the-gills restaurant during dinner rush doesn’t hold a candle to the hustle and bustle — both in and out of the kitchen — of a middle school cafeteria during the lunch hour.

While most restaurants have a leisurely dining room turnover, hundreds of students are cycled through the lunch line and sent out the door with full bellies every thirty minutes in a cafeteria setting. This presents a challenge not only for the front of the house cafeteria staff, but also requires a pretreatment plan that can go with the flow … literally.

School cafeterias feed hundreds — maybe even thousands — of children over a very short period of time. Sometimes, even twice a day. Every aspect of the operation, from the staff to the grease interceptor, needs to run like a well-oiled machine. One clog, one overflow or glitch could shut down the kitchen in an instant. 

But there are solutions.

The federal government takes grease seriously. Very seriously. In fact, the Department of Justice is ready, and willing, to issue federal jail time to any individual who knowingly violates the Clean Water Act, a standing tenet of which is proper grease disposal.

Just ask Mobile, Ala.’s DHS Inc. In 2011, the president and manager were charged in a 43-count indictment with violations of the Clean Water Act, as well as conspiracy and fraud. Their company, which was hired to remove the FOGs from grease interceptors, was, ironically, allegedly dumping the collected grease directly into local sewer systems — the same systems they were being paid to protect.

Grease interceptors do more than just keep fats, oils and grease out of the wastewater system. Properly maintained grease intereceptors protect your community's environment in a number of ways.

Imagine taking a paintbrush to the broadside of an old barn: Your goal is probably to cover the expanse uniformly with one color. But the result would likely be a lot different if you didn’t consider the number of boards you might have to replace, holes that need patching or nails that need to be driven back into the wood.

If you started blindly painting away without paying attention to each issue, you’d waste time, money and valuable resources.This same principle can be applied to standardized regulations in today’s economy. In an effort to comply with such uniform regulations, businesses waste valuable resources. 

A standardized approach can be more expensive, less effective, and less flexible than other approaches. There are alternatives, though.

There’s no reason why a sandwich shop or an ice cream parlor should be required to use same pretreatment system as a steakhouse … right?

Wastewater regulations today are often prescriptive, which means that one standard method of pretreatment is required for each of the food service establishments, or other commercial kitchens, in a municipality. Wouldn’t it make more sense, though, to create sanitary codes and ask businesses to develop their own methods of compliance?

Performance-based rules might not only do a better job, but could be cheaper in the long run, too.

The EPA estimates the total number miles of sewer lines snaking across the country to be about 1.2 million. Considering some of these lines are over 100 years old, local governments will spend billions of dollars modernizing failing wastewater systems over the next 10 to 20 years.

Because this aging infrastructure has survived decades of wear, tear and obstruction, decreasing its capability to withstand heavy demands, the probability of blockages and backups increases over time. And those blockages and backups are very likely to lead to the release of pollutants.

Not only do those pollutants threaten public health, they can also lead to fines and other enforcement actions from state and federal agencies. But there are things that regulators and waste water system users can do to reduce the burden on aging treatment systems, decrease costs and increase efficiencies.

In 1884, Nathaniel Whiting patented the first grease interceptor design. These oversized, concrete boxes are still the default choice for many in the food-service industry.

Though innovative at the time, the design of these concrete interceptors has changed very little over the past 130 years and is fraught with problems in today’s world. 

Traditional concrete interceptors range in size from 300 or so gallons to several thousand. Though there are a few different designs, they all rely on the same principle — gravity.

Wastewater from a commercial kitchen flows down through the tank, where food particles sink to the bottom and oil rises to the top. The grease-free water in the middle then exits the tank and enters the public sewage lines.

Though these grease interceptors do the job, they don't necessarily do it well, do it efficiently or do it economically.  

Think about the grease interceptor in your food service establishment.

You’ve seen it labor on through long days, lunch rushes followed by full-house dinners — the silent workhorse of the kitchen that helps keep your commercial kitchen environmentally friendly.

But, did you know that the design of your grease trap could have potentially devastating effects on the health of your kitchen staff?

When not properly designed and maintained, grease traps can become a breeding ground for bacteria that release hydrogen sulfide (H₂S), a pungent and sometimes deadly gas. This gas can cause health problems, which is bad enough. In addition, though, the gas can damage some grease interceptors, reducing their lifespans and creating potentially higher costs.

Fortunately, this isn't inevitable. Learn more about the dangers of hydrogen sulfide and how that should figure into your grease intereceptor decisions.