Following the unveiling of the Xcentric Impeller Pump during WEFTEC 2025, Pentair has now partnered with Hampton Roads Sanitation District (HRSD) to pilot the pump technology in its sewer network.

Eddie Abisaab, HRSD COO, said he and his team learned of the pump and were intrigued by its potential capabilities. As in many sewer systems, clogs and rags presented a continued challenge for sewer system and collection system managers when it came to the existing pump equipment HRSD had been using.

“A lot of rags get caught in the pump, which really creates a maintenance nightmare specific to our workforce,” Abisaab said of the pump stations prior to using the Xcentric pump. “We all know when a pump is clogged, energy efficiency is really going down the drain.”

That drop in energy efficiency also leads to a drop in performance and can also result in reliability issues in the long term. The Xcentric pump, however, allows those rags to pass through the pump without chopping or grinding them.

Roby Jones, Pentair group technology leader for commercial and infrastructure flow, noted that because it does not shred, chop or grind the materials as they pass through, the pump does not contribute to broader issues such as microplastics proliferation.

Both Abisaab and Jones explained that changes in wastewater characteristics have changed how wastewater systems operate. As one example, low-flow toilets and more water-conscious appliances conserve water and send less down the drain. The waste flushed down the drain doesn’t decrease, however, meaning the concentration in the water is greater due to the reduction in liquid flow.

“We started really looking at that and saying, ‘How could we handle solids better?’” Jones said. “We developed an impeller that is a conical shape, which almost makes it bladeless because the normal traditional sharper leading front edges are where your solids want to wrap around.”

Jones said there is a place for macerating pumps and for the Xcentric pump to coexist, but the application will determine the best pump for the job. For Abisaab, reliability was one of the critical factors that led him and HRSD toward the Xcentric design, particularly cost efficiency over the life cycle while meeting regulatory requirements. That cost efficiency, he said, also means accounting for the operations and maintenance needs over the lifetime of the pump’s operation.

“The more headaches it’s going to cause, the more complex it tends to be,” Abisaab said. “So the simpler it is to maintain a piece of equipment, the more it makes the operator and maintainer’s life easier.”

Another element that piqued Abisaab’s interest was the ability to control when and where solids in the collection system could be collected. Because the Xcentric pump lets the solids through without macerating them, it opens up an opportunity to route those solids to a single collection point before they get to the headworks at the plant, which may have additional positive operations and maintenance implications for HRSD.