Water and Effluent Treatment Magazine
Issue link: https://fhpublishing.uberflip.com/i/564644
24 WET NEWS september 2015 A s we build in more and more remote and inaccessible areas, the requirement to provide basic utilities to households and businesses becomes increasingly challenging. Nowhere is this more apparent than in the pumping of wastewater to treatment works where the development is situated below the gravity sewer, or the treatment works is situated many miles away. Traditionally, the solution has been to build a pumping station consisting of a chamber constructed from concrete rings and fitted out with pipes, valves and pumping equipment to move wastewater to the gravity main. In many areas, this can be challenging – it can take many weeks to complete the construction of a pumping station on site. This can lead to some issues relating to access, confined space working and logistics. Increasingly, developers and water companies have been looking for a cost-effective and safe solution for pumping station construction. This search has led them to look towards prefabricated options that are built off-site and ready to be installed. Prefabricated packaged pumping stations use a simple, minimal design concept that can allow ease and speed of installation and commissioning, as well as aiding the reduction of labour-intensive tasks. New regulations combined with development in more inaccessible areas are creating formidable challenges when pumping wastewater to treatment works. Xylem's rob saunders explains. The challenge: Accessing the inaccessible THE CONCEPT • packaged stations can be used where sewage or surface water needs pumping to a mains connection • the tOps benching unit lowers the liquid level in relation to the position of the pump inlet • packaged pumping stations offer a simple and cost effective means to transport wastewater NEED TO KNOW 1 It can take many weeks to complete the construction of a pumping station on site 2 Developers and water companies have been looking for a cost-effective and safe solution for pumping station construction 3 the sewers for Adoption legislation sets out guidelines to ensure developers build compliant pumping stations 4 sediment movement in a pump sump differs from that in a sewer. THE VERDICT "by being designed off-site and meeting the required standards, containerised pumping stations can be installed quickly and simply, offer vital health and safety benefits whilst reducing plant downtime and ensuring treatment works can maintain optimum performance levels rob saunders" INSIGHT INsIght pumps & vAlves by being designed off-site and meeting the required standards, containerised pumping stations can ensure treatment works maintain optimum performance levels A solution: A packaged deal P ackaged pumping stations can be adapted to suit most individual require- ments. For example, the Flygt packaged pumping station range from Xylem can meet the requirements of many applica- tions including domestic waste- water for a single household, through to large housing devel- opments, effluent and wastewa- ter from industrial units and commercial premises. In fact, they can be used in almost any situation where sewage or sur- face water needs pumping to a mains connection. Packaged pumping station chambers can be also used to augment exist- ing arrangements. The Sewers for Adoption (SFA) legislation sets out guide- lines to ensure that developers build pumping stations that are compliant with the specifica- tions agreed by the local water company, to allow them to be adopted at a later date. These guidelines effectively mean that many pumping sta- tions needing full replacement or refurbishment also have to meet the standards set out by the local water company. The legislation is set in place to ensure that pipework, valve ensuring the pumping station can be integrated into the exist- ing sewerage system quickly and simply. Another important aspect of the sewers for adoption process is the transportation of solids through the sewerage system. Sediment movement in a pump sump differs from that in a sewer. The flow in a sump is less regular, in terms of both direc- tion and capacity. With inter- mittent pump operation, a pump sump periodically acts as a settling tank. The accumula- tion of sludge leads to the build- up of harmful gases and requires periodic desludging of the sump, which can increase operational costs. The optimal sump, in this context, should be small enough to prevent the set- tling of sludge yet large enough to avoid obstructing pump operation. Xylem's TOPS series of Flygt Packaged Pumping Stations incorporates a self-cleaning benching unit which reduces the accumulation of solids on the sump of the chamber. Float- ing solids, similarly to the set- tling ones, can only enter the pump if they are within the influence of the pump suction. The patented TOPS benching unit lowers the liquid level in relation to the position of the pump inlet, ensuring a larger amount of solids can be transported. Packaged pumping stations offer a simple and cost effective means to transport wastewater. By being designed off-site and meeting the required stand- ards, containerised pumping stations can be installed quickly and simply, offer vital health and safety benefits whilst reducing plant downtime and ensuring treatment works can maintain optimum perfor- mance levels. n Rob Saunders is Packaged Pump Stations Market manager at Xylem. Whereas traditional pumping stations can take between six and eight weeks to install, a packaged pumping station can be fully installed or integrated with an existing system within one week. Furthermore, contain- erised pumping stations can be designed, manufactured and tested off-site ensuring the operational activities of the client are not affected. the tOps series incorporates a self-cleaning benching unit that reduces the accumulation of solids on the sump of the chamber layout, pump types, level and control specifications all con- form to the required standards. From a civils building con- tractor's point of view, the tradi- tional method for adoption authority can be a long and complicated one involving sub- missions forms and potentially long turnaround times. Pack- aged pumping stations meet all the design criteria specified by individual water companies, reducing installation times and packaged pumping stations can augment existing arrangements, as well as meet the design criteria for all concerned.