Fighting Lift Station FOG

Active mixing eliminates grease problems with less resources and no chemicals

Fighting Lift Station FOG

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Lift station operators often rely on grease-dissolving chemicals to manage FOG in lift stations, but Farmers Branch, Texas, is taking a different approach. 

Chemical treatment can be effective, but it carries potential drawbacks including the need for repeated applications and possible environmental impacts. Engineers are constantly working on different approaches to these issues, and one such solution has gained support in Farmers Branch. 

That’s one reason innovative engineers have been striving to create alternatives for lift stations. Kasco’s new HydraForce product line is specifically designed to address wastewater problems, and the HydraForce Lift Station Agitator builds on the strength of Kasco’s proven diffused aeration products. 

Tested at a public works facility in Farmers Branch, Texas, the HydraForce Lift Station Agitator was found to dramatically reduce greasing, eliminating the need for continual grease remediation and ultimately saving the city thousands of dollars. 

A greasy situation

James Ryan Sartor is the director of Public Works in Farmers Branch, a Dallas suburb with a population of approximately 36,000. Changing dynamics at a lift station brought unexpected problems that Sartor had to solve.

“In its early years this particular lift station only served a couple of large commercial complexes, and it operated perfectly fine at that time,” Sartor says.

But that changed in 2017. 

“There was a proposed housing development in Farmers Branch that grew beyond its original projected size,” Sartor says. “It morphed into multiple single-family developments as well as several large multi-family apartment complexes. We had to upgrade to handle the increased flow, and as these new additions to the city were being occupied, we noticed the lift station was developing a grease issue.”

Greasing is a significant problem in wastewater lift stations that can lead to operational issues and maintenance challenges. Grease primarily comes from sources such as kitchen sinks, dishwashers and food processing facilities, where fats and oils are often washed down drains.

When grease enters the sewer system, it can solidify and adhere to the surfaces of the wet well, pipes and pump impellers.

Grease buildup can reduce the effective volume of the wet well, potentially leading to decreased pump efficiency and increased pump cycling. It can create blockages in pipes and impellers, causing pumps to clog and malfunction. Over time, if not addressed, grease accumulation can lead to costly maintenance and repairs. And in severe cases, it can cause lift station failures and sanitary sewer overflows, posing health and environmental risks.

Chemical remediation

Effective prevention and management strategies, along with regulatory measures and public awareness, are essential to mitigate the impact of greasing on lift station performance and the overall sewer system.

“In the early stages, we were able to control the issue using various chemical treatments and cleaning methods,” Sartor says.

Lift station operators often use chemical agents to break up grease accumulations within lift stations and associated sewer lines. Containing enzymes, bacteria, surfactants or other active ingredients, these chemicals are typically known as grease digesters or grease solvents, and are designed to help mitigate the problem of grease buildup. 

Grease-dissolving chemicals work by breaking down the fats, oils and grease into smaller, more easily dispersible components. Applied directly into the lift station’s wet well or introduced into the sewer lines upstream of the lift station, this process helps prevent the formation of solid grease deposits on lift station surfaces and in sewer pipes.

But some grease-dissolving chemicals may have environmental impacts, and their effectiveness can vary depending on factors such as the type and concentration of chemicals used, the severity of grease buildup and the hydraulic conditions within the lift station. Many local and municipal governments have regulations and codes in place to control the discharge of FOG into the sewer system as well. These regulations often require businesses to implement FOG control measures and undergo inspections to ensure compliance.

Furthermore, grease-dissolving chemicals typically require regular application to maintain their effectiveness. This can add ongoing operational costs and maintenance tasks to lift station management.

Such was definitely the case in Farmers Branch. “As the service area began to grow, the cost of managing the grease issue was growing as well,” Sartor says.  

The active mixer

After a lengthy search for solutions, Farmers Branch was approached by Axis Construction to look at an existing technology from Kasco that had been used in aquatic applications such as residential and commercial pond management, stormwater retention ponds and more. That technology was Robust-Aire, an underwater diffused aeration system. 

There are several benefits to using a device that physically mixes water to break up grease in wastewater lift stations, either in combination with or as an alternative to chemical treatments. Mechanical mixers use physical agitation to break up grease deposits and keep them in suspension in the wastewater. This mechanical action can help prevent the formation of solid grease layers on the surface of the water or the wet well.

“I was very interested in the product,” Sartor says. “After examining its design and construction, I talked with Axis about installing the device in a lift station wet well for grease remediation. By March of 2022, Axis had completed the installation, and we spent a couple of weeks tweaking its placement and levels.” 

Within just a couple of months, big changes began happening.

“By early May,” Sartor says, “we started to experience amazing results. The station was staying very clean, the water was clearer, and there was far less odor. We continued to see these kinds of improvements through the following year. Fast-forward to August of 2023, we’re no longer using chemical treatments in this lift station at all. At most, we may experience a small grease deposit in the far corners of the lift station, and those are easily washed down and dissipated.”

The savings to Farmers Branch in terms of expenditures and human resources were also dramatic.

“Our chemical treatments had been costing us thousands of dollars a year,” he says. “We were using equipment and personnel for grease remediation every two to three weeks. We now perform our standard weekly inspections of this site and have yet to experience a need for grease removal since installation.”

Sartor notes he expects his experience with the Kasco HydraForce Lift Station Agitator to provide even more benefits down the road.

“This piece of equipment has greatly improved our operations. We are conducting a major lift station rehab starting later this year, and I am excited to have the balance of our lift stations retrofitted with this device very soon.”


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