Suck it up, pressurize it and send it to the treatment plant.

In theory, this should be a straightforward job for pumps at a lift station. However, as we all know, the curse of so-called “flushable” products in our sewer systems is also proving that some so-called “nonclogging pumps” are getting clogged.

If you don’t have a problematic lift station in your network, you’re either lucky or have the most environmentally responsible residents in the country. Or perhaps you’ve already solved the beast of a problem with a piece of equipment that has been around for over 70 years.

As more and more maintenance teams contend with the rise in non-biodegradable products, problems for wastewater lift stations are almost inevitable. This critical piece of infrastructure is further hindered by today’s low-flow household wastewater systems that honorably save water but allow solids to build up.

Unclogging the supposedly nonclogging pump can be a thoroughly unpleasant job, especially for example, in Daphne, Alabama, where its main lift station at Windscape was besieged with ragging issues to the point of having a vac truck there at least once per week. All part of the job, maybe, but burning up hours of labor returning to the same problematic lift station again and again can be demoralizing. The fact that some of those first to complain about backup and odors might include people who have contributed to the problem is not lost on the engineers who are doing their best to make things right.

At Daphne Utilities, the top priority is always to provide a reliable wastewater collections and treatment system that supports the needs of its community, protects the environment and quality of life for all Eastern Shore residents, and meets or surpasses all federal and state requirements. The Daphne Water Reclamation Facility can treat up to 4.17 million gallons of wastewater per day, but has the hydraulic capacity to process up to 9 mgd. The facility serves approximately 12,000 homes and businesses and treats an average of 3 million gallons of wastewater every day.

The utility has an extensive cleaning program in place, as well as a comprehensive pretreatment and grease management program to combat fats, oils and grease. This includes the requirement for grease interceptor devices at all food service establishments and for car wash establishments to have sand/oil interceptors.

Critical infrastructure

Despite all these proactive measures, the recurring problem at Daphne’s Windscape lift station was getting some unwanted attention within the community.

“We have two 88 hp pumps but were still having ragging issues. Our power source was also unreliable, so our bypass pumps would soon become clogged,” says Goeff Wilkins, water reclamation facility manager. “Windscape is our primary lift station, which with seven others feeding into it, handles about 1 million gallons per day or about 1,500 gallons per minute, so it’s a very critical part of our network. I know some operators choose to use chemicals to address certain issues, but with wastewater being more aggressive, we wanted to find the best long-term pumping solution.”

Always on the lookout for technologies to improve the reclamation facility and its sewage network, Daphne Utilities had established a link with leading process equipment provider, Cahaba Water Solutions, based in Birmingham. Cahaba suggested testing an EradiGator from Landia, which is based on the very same chopper pump design that Landia invented back in 1950. Goeff Wilkins and his key engineers had also attended two national trade shows to weigh the best options.

Demonstrating effectiveness

“Daphne Utilities continues to be proactive in addressing and solving issues in their collection systems. However, like all utilities, there is always a pump station where there will be a continuing heavy presence of non-biodegradable products,” says Tim Boyne, owner/president of Cahaba Water Solutions. “We felt if we could demonstrate the performance of the Landia EradiGator under these tough conditions, we could greatly reduce their operation and maintenance costs at the Windscape station as well as reduce the potential of overflows from clogged conditions.”

At the trial, Wilkins and his team could immediately see the chopping and mixing of the 20 hp Landia EradiGator.

“It immediately resolved the issues in the Windscape lift station, so we had no hesitation in investing in it,” Wilkins says.

Set up on a timer to operate for 15 minutes per hour, the Landia pump now effectively protects the two existing 88 hp pumps with its chopping and mixing action. The EradiGator’s external knife system also prevents unpumpable solids from entering the pump’s casing.

“It does a phenomenal job,” Goeff says. “We can really see the difference at the headworks to our facility where there is now much less debris. We’ve saved huge amounts of time by not having to pull out the clogged duty pumps or send in the vac truck. Through SCADA and from daily inspections, we still check for any signs of matting and ragging, but the Landia EradiGator doesn’t need much maintenance. It works fantastic.

“Cahaba has been very helpful in finding us such a solid yet simple long-term solution to the issue we had with our main lift station. None of our team misses having to go there all the time.”