Reduces Maintenance Issues with Retrofit Wastewater Pumping Solution

Harleyville, S.C. — With a population of 677, the small town of Harleyville, S.C., located 60 miles northwest of Charleston, was looking to upgrade its aging lift stations to increase efficiencies, lower utility costs and reduce overall pump maintenance for its municipal wastewater facility.
The town employed six lift stations—five of which utilized grinder pump systems from 1985—to consolidate wastewater and pump it to a centralized wastewater processing and treatment plant.

The 25-year-old lift stations each suffered frequent clogging, expensive maintenance and repair, and skyrocketing monthly utility bills related to extended pump run times. In fact, the reliability of the entire wastewater transfer system seemed to derail every three to six months, when a pump outright failed or a station backed up because the pumps were unable to keep up with demand.

Working with global engineering consultant URS Corporation, the town began its system update by retrofitting one lift station with energy-efficient wastewater pumps from Grundfos. The improvement was dramatic and led to upgrades at two additional lifting stations. As a result, Harleyville has reduced energy use by 35 percent and cut $25,000 in annual maintenance and repair expenditures.

Efficient Pumps Slash Run Times; Energy Use

“Due to the greater pumping capacity of the Grundfos SLV pumps, the station’s run time dropped by roughly 80 percent,” said Dan Huggins, P.E., project manager, URS Corporation, who noted that peak pump operation fell from an average of 18 hours per day to 3.5 hours per day (factoring in median rainfall and infiltration amounts).

The additional pump capacity combined with the reliability of the SLV Series’ pumps made an immediate impact on the trouble-plagued system. “Since power consumption accounts for 85 percent of a pump’s life-cycle costs, likely the most dramatic savings for this project is the ability to maximize pumping performance, across each lift station,” noted Robert Pruit, principal of Carolina Pumpworks, who worked with engineer Huggins to incorporate the SLV pumps.

“Some of the town’s outdated pumps were running nearly non-stop during increased flow events to keep the wet wells from overflowing. For example, when rainfall swelled the volume of flow into the town’s sewer lines, both of the pumps at each of the individual lift stations would typically run for extended periods of time to deal with the increased flow.”

Added Capacity & Redundancy

In all, the three newly upgraded duplex lift stations each feature two 5.5 HP, 1,750 RPM three-phase pumps that alternate operation according to the station’s level control system, which offers both system redundancy and added capacity during increased flow events. To overcome prior difficulties with pumps clogging, the team selected the optional SuperVortex impeller, to help ensure that solids up to 3-inches in diameter pass freely through the solids-handling pump without jamming.

Carolina Pumpworks also provided custom-designed control panels
to meet Harleyville’s requirements. The control panels included the Grundfos IO113 pump monitor relays, that together with the pump sensors, provides more protection against thermal overload and seal leakage.

The transformation began in October 2011 when—with the aid of state grants— the town installed its first SLV pump system at Pump Station 5 as a retrofit application.

This aging lift station served 125 residents and pumps sewage one quarter mile to the next manhole and was plagued with service issues.
“The old pumps frequently clogged and the resulting motor stress forced a pump removal—and repair— roughly every six months,” recalls Harleyville Maintenance Superintendent Tommy Weeks. “Pump maintenance for this station alone was running nearly $4,000 a year.”

Designed to handle raw unscreened sewage, effluent and process water in municipal applications, the SLV series pump with its recessed super vortex impeller was an ideal solution for the initial lift station retrofit. The upgraded Lift Station 5 has been operating maintenance-free from its initial start-up in 2011 without a single incident of clogging.

“These new pumps have really helped mitigate any maintenance costs that we have had in the past due to pump ‘burn-out’ and clogging,” explained Weeks. “In addition, these pumps help reduce build-up in the gravity lines because they pump more volume more quickly. After more than three years and 2,000 hours run time under Station 5’s belt, the pumps have proven themselves to be ‘solid performers’ and the ideal solution for our wastewater system.”

In fact, the pump’s performance was so dramatic that URS project engineer Dan Huggins knew that when the time came to rebuild Lift Station 4—the weakest link in the town’s wastewater system—they would tailor the station around the Grundfos SLV pumps.

State Funding Leads to Additional Pump Upgrades

Due to the success of Lift Station 5, when more state funding became available in 2013, Harleyville upgraded two additional lift stations with the SLV submersible pumps. Both projects were up and running by December 2013.

The original 4-foot wet well at Lift Station 4 was too small for the raw sewage intake and required a complete overhaul. The pumps in Station 4, which serves 250 people, were running nearly continuously in an attempt to keep up with the sewage flow. As a result, the station lost a pump to repairs roughly every three months, resulting in an annual maintenance cost of $15,000.

Following completion of the Lift Station 4, a local hotel and an apartment complex were constructed nearby. The high performing lifting station has not faltered in managing the increased sewage flow from these facilities.

Speaking on the importance of receiving grant money for the new Lift Station 4, Mayor Charles Ackerman said, “This grant money will let us build a whole new lift station and reroute the force main to a different manhole, which will save us time and energy. We desperately need this; we’ve had a lot of problems with that station. It has a lot of water com-ing into it, a lot of sewage. This will be a tremendous help to the town.”

Following the reconstruction of Lift Station 4, the town upgraded an additional lift station with two similar Grundfos SLV series pumps. Like the other aging lift stations in the Harleyville system, the outdated pumps in Lift Station 2 required service every six to seven months.

Tommy Weeks, the town’s maintenance superintendent, estimates that the new pumps at Lift Station 2 will eliminate approximately $4,000 in annual maintenance costs.

Putting Repairman Out of Business

The goal moving forward for Harleyville will be to upgrade the remaining lift stations with the SLV pumps, when more state funding becomes available.
“We’ve come a long way to ensuring the integrity and operational efficiencies of our wastewater system,” concludes Weeks. “There are zero maintenance costs or issues with the new pumps. I chuckle each time the repairman—accustomed to a significant amount of business from us—calls to ask when we think one of the pumps will be in for repair.”

PROJECT SNAPSHOT

Harleyville, South Carolina
6 lift stations @ average 100-150GPM/ea serving 600 residents

Savings

35% in Utility Cost/year
$25,000 in Maintenance Costs/year

The Challenge

The Town of Harleyville, S.C. was looking to upgrade its lift stations due to increased pump run times and maintenance costs.

The Solution

Carolina Pumpworks, worked with Harleyville’s Consulting Engineer, URS Corporation to specify and install Grundfos SLV pumps—with SuperVortex impellers at three of the six lift stations. The pumps pro-vided increased operational efficiencies and reduced maintenance requirements.

MEMCOR® XP MEMBRANE SYSTEM

Innovative upgrade averts potable water crisis and delivers lasting value

HIGH QUALITY WATER WITH A LOW PROFILE.

A better control over the flow

With its proximity to Interstate 70, the town of Georgetown, Colorado has always enjoyed a continuous flow of tourist traffic. But like many other quaint mountain communities in Colorado, it relied on media filtration technology to meet the local population’s demand for drinking water.
In Georgetown’s case, a 1960’s era diatomaceous earth (DE) filtration system provided the primary treatment of water out of South Clear Creek. The town’s existing filters forced operations staff to tend to the plant on a 24/7 basis during times of high turbidity in the feed source, and resulted in frequent shutdowns that threatened the overall quality of the treated water. Adding to the challenge was the water treatment plant’s location in a narrow canyon on the edge of town, which all but eliminated the possibility of settling out the turbidity in the feed prior to the DE filters. There was simply no space to pre-treat the feed water.

EYEING A CLEAR WATER TREATMENT SOLUTION

Georgetown’s commitment to supplying the highest quality water to
its citizens led the town to focus on treatment technologies that would provide reliable pathogen and turbidity removal. In addition to these goals, the town also had to consider the limited space available for a new solution, along with technologies that could reduce the operational intensity of the water treatment process.
Working with Frachetti Engineering, Georgetown officials weighed several options before selecting the MEMCOR® XP system, a proven membrane ultra-filtration (UF) technology that would not only meet the town’s specific needs, but also deliver multiple operational efficiencies.

EFFICIENCY THAT MAKES AN IMMEDIATE IMPACT — MEMCOR® XP SYSTEM

The MEMCOR® XP system uses the most advanced, industry-proven membrane filtration technology. Fully assembled and factory tested, the self-contained unit is shipped ready-to-run, substantially minimizing integration, installation and start-up costs.

Ideally suited for small communities and industrial applications where suspended solids removal is critical, the MEMCOR XP system’s straight forward and compact design maximizes efficiency and reliability to produce the quality and quantity for communities need.

SIMPLE INTEGRATION AND LONG-TERM OPTIMIZATION

Arriving in Georgetown fully assembled, the MEMCOR XP system small footprint easily fit within the tight constraints of the treatment plant, and substantially minimized the project installation requirements compared to erector-set type alternatives. The system‘s gravity feed compatibility provided additional efficiencies by eliminating the need for feed pumps to drive the filtration process.

Since initial start-up in 2011, the MEMCOR XP system has continued to provide the Georgetown community with consistent and reliable high-quality water.

The city of Louisville, Ohio installed a 3 mm Or-Tec Blue Whale Microbar Screen in its wastewater treatment plant in November 2018 to screen hair, wipes, plastics and other ’rags’ from its influent wastestream. Louisville is a bedroom community with around 10,000 residents and a few light businesses. Its plant is designed to treat up to 6 million gallons of wastewater per day.

The 3 mm Or-Tec Blue Whale Microbar Screen replaced a 10-year old perforated band screen that was failing and had, in fact, been problematic from the start. “I was never happy with it (band screen) from when it was new,” explains Chief Operator Rich Goebeler, “We always felt like it was only capturing maybe 50% or 60%.” To compensate, operators used a hand rake located downstream of the band screen after aeration and before final clarifiers to remove four to eight 5-gallon buckets of material each day.

The band screen also needed a lot of repairs. Both the brush and pillow blocks on its bearings needed to be replaced after a few years. Then, after just six years, the stainless-steel keepers holding the rubber channel seals oxidized off.

“They were gone,” recalls Goebeler, “leaving debris to bypass the actual screen around the sides.” The band screen company offered a pricey “update” kit to fix them. This upset him. He recalls telling them, “But the other ones rotted off! Can’t you give us a price break? I mean, they were bad after six years!”

Hundreds of the band screen’s chain plates were also bent, allowing even more material to bypass the band screen. Hand raking became a constant chore. “The guys would go out three or four times a day and clean off the (hand rake) screen,” explains Service Director Dan Milsap. “They would rake buckets, and buckets and buckets of hair and other material that was going through the (band) screen.”

In short, Goebeler says, after just ten years, the band screen needed a complete overhaul. With repairs approaching $20,000, the city decided to abandon it.

After research, recommendations from another Ohio wastewater plant and bidding, Louisville chose the 3mm Or-Tec Blue Whale Micro Bar Screen. “I was impressed with the 3mm opening that they (Or-Tec) had and what it was pulling out of the system,” Milsap says.

The city has not been disappointed. “The Blue Whale has been great,” Milsap says. “I believe we have been very fortunate. It has kept up with our peak flows at the plant. It’s probably been one of the best products that we purchased over the years.”

The new Or-Tec 3mm Blue Whale Microbar Screen is removing enough debris to fill a 2 cubic yard dumpster each week. This is in sharp contrast to the band screen, which was filling just one third of the dumpster weekly.

As expected, hand raking has decreased sharply. Goebeler says that operators are hand raking just a ½ gallon bucket of debris a day, and he expects it to continue to decline. “Our system is still cleaning out,” he explains, “I think we will keep getting less and less debris out.”

Goebeler is impressed with the ease of mainte-nance of the 3mm Or-Tec Blue Whale Microbar Screen. “It’s something that we don’t have to give constant attention to,” he notes. “It’s just down there running, doing its job.”

He says that the only maintenance has been routine. Operators grease the main shaft bear-ings every two weeks. Downstream maintenance has also decreased., including less cleaning and fewer replacement parts. “It’s saving on man hours. It’s saving on time. We couldn’t be happier with it,” Milsap says.

Water savings are also enormous. The 3mm Or-Tec Blue Whale Micro Bar does not require wash water. Goebeler says that the old band screen used 60 gallons of wash water per minute.

On average, this meant that it used about 26,000 gallons of wash water per day, but he says even that is a ‘very conservative” estimate. He says that because the former screen ran based on the level in the channel, rainy or wet periods would cause it to operate continuously – using approximately 16,440 gallons per hour, or 394,560 gallons per day.

“First, we have the water savings, then the reduced maintenance, “ Goebeler says. “I just feel that it is a very good piece of equipment and I would highly recommend it to anyone else.” Milsap agrees.

Goebeler and Milsap say that working with Or-Tec was terrific. Milsap was especially impressed with the help the company provided during installation.

Milsap said Or-Tec was right there on site helping. “You always wonder how the transition is going to go when you are replacing a piece of equipment of that size and importance, but it was seamless,” he says.

“(Or-Tec) helped us out a ton with the installation. They were there answering questions. They pretty much led the installation portion of the project and we’re grateful for that. It really, really helped us out.”

“The whole (Or-Tec) crew was great to deal with,” Milsap emphasizes.

The OR-TEC Blue Whale Micro Bar is completely unique screen because it can screen to openings as small as 1mm while not blinding due to its tapered bar construction and pene-trating rake teeth. This US patented screen is manufactured in an ISO 9001 and ISO 14001 factory and eliminates downstream matting without the use of wash water or brushes. This very high removal rate vastly improves the rest of the wastewater treatment plants operation by reducing fouling of pumps, valves and other rotating equipment.