Pumps Provide Lift Station Reliability

May 27, 2008

Sewage collection and treatment authorities across the nation are concerned with maintaining lift station pumping capacities during system failures.

Traditional design has incorporated a diesel-powered generator to provide backup electricity in the event of a power failure at the station. Now, tradition is being broken as sewage authorities discover the benefits of backup pumping capacity instead of backup electrical capacity.

Backup pumping capacity supplied by the Godwin Dri-Prime automatic self-priming diesel-powered pumpset provides lift stations with 100% pumping redundancy for emergencies, power outages and scheduled preventive maintenance. The reliability issues of transfer switches and control panels of traditional lift station designs becomes a thing of the past. The following three case studies illustrate how backup pumping capacity has improved lift station reliability and flexibility.

City of Hoover, Ala.

Lift station reliability had become such an issue that city engineers decided to research the cause of outages. Their findings were surprising. They found that only 14% of lift station outages were directly related to power failures. “Our discovery that a large percentage (86%) of lift station failures were caused by either mechanical pump or electrical control panel failures was a huge wake-up call for us,” said Phil McGraw, civil engineer, city of Hoover.

McGraw had used diesel powered portable pumps on a temporary basis during emergency repairs for permanently installed pumps and was impressed by the reliability. He knew a Godwin diesel Dri-Prime pump was what he needed as a backup system.

Dri-Prime pump with engine cover and locking door.

As a result, the city of Hoover devised a plan in the mid-1990s to convert all of its 40 lift stations over to Godwin Dri-Prime pumpsets instead of electrical generators. The Godwin 6-in. CD150M Dri-Prime was the first pump purchased for this application and it is still operating to the city’s satisfaction. Today, over 30 stations have been completed.

Orange Water & Sewer Authority, N.C.

Orange Water and Sewer Authority (OWASA) of Carrboro and Chapel Hill, N.C., initially purchased a Godwin HL10M Dri-Prime pumpset and trailer for a bypass needed in its wastewater treatment facility during a clear well upgrade. In addition, OWASA used the HL10M pumpset for six weeks to provide supplementary pumping while installing permanent pump upgrades.

Two DPC300 Dri-Prime pumps at OWASA in North Carolina.

“Godwin was responsive and really worked with us to provide quotes, engineering and service—all with very short notice. They were also terrific with follow-up,” said Barbara Oslund, OWASA engineering manager. “I recommend that municipal engineers talk to Godwin before undertaking similar projects.”

“These pumps have other uses, too,” Oslund said. “We’ve put the trailer and original pipe configuration into storage and are now using the HL10M at our raw water pumping facility as a contingency during power outages.”

In a separate application, OWASA used two Godwin 12-in. DPC300 Dri-Prime pumpsets at its wastewater treatment facility. The pumps, designed as critically silenced units, solved the challenge of providing enough capacity to meet peak demands until a major system upgrade could be completed. As permanently installed pumps at the station were taken off line and upgraded, the DPC300 Dri-Prime pumpsets provided supplemental pumping capacity during high-flow conditions.

“I was against diesel pumping initially, but I sure see the benefits now,” said Johnny Johnson, OWASA’s maintenance manager. “Godwin’s solutions have really helped us during our system upgrades.”

OWASA asked Godwin Pumps representatives to advise on a contingency plan to deal with the impact of coastal storms and hurricanes. As a result, Godwin has contingency plans in place with seven of OWASA’s pump stations.

Maryland Environmental Services

Maryland Environmental Services (MES) operates lift stations for a correctional facility in Jessup, Md. As part of a planned lift station upgrade, MES’s consulting engineer contacted Godwin Pumps to provide the backup system design required on the project.

Godwin designed backup pumping systems at two lift stations. Each pumping system consisted of a Godwin 8-in. CD225M Critically Silenced Dri-Prime pumpset that was skid mounted and permanently installed with the capability of pumping up to 3 million gal per day.

Critically Silenced Dri-Prime pump in Jessup, Md.

Correctional facilities operate on an increased maintenance schedule that requires more pump servicing, generator exercising and line clearing than at a typical municipal lift station. Therefore, MES required double backup systems for the permanently installed electric submersible pumps at the station. The Godwin Dri-Prime pumpsets provide the secondary backup in the event of a primary backup system failure. The additional reliability provided by Godwin’s self-priming diesel pumps meets MES’s standard for a 100% operational guarantee.

“Those Godwin pumps start every time and do the job,” said Harry McNally, maintenance supervisor for MES. “They give me peace of mind knowing those diesels are there to back us up.”

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