Large housing developments that cannot connect to the main sewer by gravity, require packaged pumping stations to perform the vital task of safely removing wastewater. They must be designed to water company standards and here, Helen Wilson, industry & infrastructure UK manager at Xylem UK, answers the questions developers may ask before selecting a pumping station.
What is a packaged pumping station?
Packaged pumping stations (PPSs) are factory-built systems that pump wastewater and stormwater from a site into the public sewer network for treatment and disposal.
Does my development require a packaged pumping station?
The systems are typically used where a development cannot connect to the public sewer system by gravity. It may be situated below the network, in a remote or inaccessible location, or is a considerable distance away from the main sewer, making a traditional gravity-based system unfeasible or not cost effective.
Do I need to liaise with the local water company before installation?
If you are constructing sewers or pumping stations as part of a new development, it is advisable to apply for an S104 connection in the design phase of a new project. This process allows the local water company to adopt the new sewerage system under Section 104 of the Water Industry Act 1991. By doing so, you ensure that your development complies with industry standards and that the sewer network is properly integrated into the existing infrastructure.
The station design and installation must comply with the industry’s Sewage Sector Guidance (SSG), a suite of documents that sets out adoption requirements including for location, size, pipework, valve layout, pump types, level and control specifications. The SSG was introduced in April 2020, replacing the Sewers for Adoption guidance.
How long will it take to install a packaged pumping station?
PPSs are pre-assembled units which are delivered to site fully kitted-out with components including pumps, pipes, valves and controls. This means the installation process is simple and can be arranged to suit programmes work, saving onsite build-time and reducing disruption.
Xylem’s Flygt brand offers a comprehensive range of packaged pumping stations which it aims to specify, price and supply within four to six weeks. To avoid any site-specific issues, Xylem engineers will work with the developer to clarify details such as, where will the station be situated? Does it have clear access? Has the correct access cover been specified? And, importantly, has a groundwater survey been carried out?
Who will be responsible for the management and maintenance of the pumping station once installed?
Water companies and New Appointments & Variations (NAVs) - limited companies selected to run water and sewerage services in specific geographic areas, are recognised as the most suitable owners of sewerage networks. Once satisfied the pumping station has been completed to the agreed standard, the utility will adopt the asset and take over its management.
Before this can happen, a pre-adoption onsite inspection is usually carried out to ensure all works have been completed as per the design. Representatives from the water company, the developer and, where Xylem is the supplier, a member of its engineering team are all involved.
As a turnkey service provider, Xylem offers developers a pre-adoption advisory service and full technical submission to be used to apply for a S104 legal agreement.
Are packaged pumping stations easy to maintain?
The right packaged pumping station will provide efficient and reliable pumping for new housing, from single dwellings through to major developments. Models with high-end pumps will provide decades of service and, in the long-term, be more efficient than alternatives such as septic tanks or onsite treatment units.
Xylem’s engineers advise at least one service visit per year to lift and check the electrical pumps. If the station is found to receive large volumes of unflushable items, such as wet wipes and nappies, they would recommend up to four visits per year.
Are smart pumping stations now available?
As urbanisation increases and developments expand into more remote and inaccessible areas, the need to efficiently pump wastewater to treatment works becomes an ever more crucial consideration. As such, the technology is becoming more intelligent to meet changing customer needs.
One example is the Flygt Concertor, which was the world’s first wastewater pumping system with integrated intelligence. The smart system is capable of sensing the operating conditions of its environment, adapting performance in real-time and providing feedback to operators.
