USA
Challenge
The James Island Public Service District (JIPSD) Wastewater Department is responsible for maintaining the public wastewater collection system, which also serves about 13,000 retail customers and one wholesale customer, although the developmental growth on James Island continues to increase the service area. The wastewater collection system consists of gravity pipelines, lift stations, and force mains conveying wastewater to Charleston Water System’s Plum Island Treatment Plant. JIPSD’s Wastewater Department maintains 61 pump stations and seven pump stations for the City of Folly Beach, which are part of a system that provides collection services to all wastewater areas of the island, including the Town of James Island, the City of Charleston, and the City of Folly Beach residents.
In 2011, JIPSD commissioned the construction of a wastewater pump station equipped with a pair of submersible pumps powered by drives on a programmable logic controller. It is not uncommon for wastewater pumps to collect fibrous materials that subsequently cause blockages. This phenomenon is known as “ragging,” and it can occur several times a day, requiring a cleaning that is as unpleasant as it is expensive.
Solution
In April 2015, JIPSD installed the N3171 in position one at the pump station. About two weeks later they had to remove the original pump from position two for cleaning. The pump in position two had apparently already been ragged up when the first Flygt pump was installed. Since the N3171 was put in place, they have had no callouts to that station for low flow or ragging. JIPSD is already quite impressed with the Flygt pump, which cleans the sump so well that the neighboring submersible pump no longer suffers from ragging issues. Regardless, JIPSD intends to order a second N3171.