Lagoon cover dewatering solution for Gippsland Water

Gippsland Water provides quality water and wastewater services to the Gippsland region of Victoria, supplying drinking water to 76,490 households and businesses and wastewater services to more than 69,000 households and businesses, across 43 towns. With 375 operational, engineering, financial, environmental and administrative employees, it is a major local employer for the region, serving an estimated population base of over 165,000.

With a number of sites with floating covers, the utility was experiencing issues with its cover dewatering pumps. Motors were burning out due to dry running; pump suction lines were clogging with debris, plant material and sludge build-up; pumps were not priming; and mechanical seals were breaking. This all created a lot of maintenance issues, both on the cover and with replacing, priming or repairing pumps.

The solution

Justin Tile, Project Engineer Asset Delivery, reached out to Hydro Innovations’ Regional Manager, Graeme Spence, to discuss a better solution.

With long suction lines of 40–50 m, low flow requirements and discharge to nearby drains, it was decided to trial a Ragazzini peristaltic pump. Hydro Innovations offered a trial based on performance. The pump utilises a ‘roller-on-bearing’ design, which eliminates the need for lubrication fluid inside the pump housing because there is no friction on the surface of the tube/hose. This minimises the chances of contamination and results in a longer tube life. The pump also requires smaller drives, so less power is needed compared to other peristaltic pumps to get the same rpm and capacity.

With no lubrication fluid required, hose replacement is greatly simplified and cheaper without having to drain and dispose of a messy and expensive oil or glycerine solution. The dry casing also allows for the use of Ragazzini’s early leak detection system — standard with the pumps — to alert operators when hoses need replacing.

The results

The Ragazzini pump is robust and is suitable for the hydraulics of the duty. As the pumps are self-priming, there is no need for a foot valve out on the cover.

The pump was installed with little fuss as minimal pipework adjustment was required. Once it was turned on, it quickly proved how effective it is in this application. Priming of the long suction line was achieved in approximately 25 seconds with no foot valve. The pump has been successful in this application, reduced the need for access to the cover and decreased maintenance callouts.

Tile said he has been very happy with the whole process, with honest support from Hydro Innovations and proven performance from the pump. He said this will be the way forward now for cover dewatering.

Image caption: Gippsland Water Lagoon cover dewatering. Image supplied.