Veolia Water Technologies UK (VWT UK) supplied its AnoxKaldnes™ K5 moving bed biofilm reactor (MBBR) system to Hooe Wastewater Treatment Works (WwTW). Selected to help the site meet tougher new permit requirements in a critically short time-frame, VWT UK’s MBBR solution provided an effective, small footprint solution that met the required improvements in the final effluent discharge.
Located close to a large village in East Sussex, Hooe WwTW had been tasked with tightening the final effluent discharge permit figures of its site of operations. As part of this, Hooe WwTW had to meet new requirements such as 85%ile Ammonia (NH3) permit of 12mg/l, a 95%ile Biological Oxygen Demand (BOD) permit of 20mg/l, a Total Phosphorus (TP) permit of 0.7mg/l and a 95%ile Suspended Solids (SS) permit of 40mg/l. Other requirements included a 95%ile Iron (Fe) permit of 4mg/l and an Upper Tier Iron permit of 8mg/l.
The wastewater treatment solution had to be installed and operational before the regulatory date of 31 March 2020 came into effect. Initially, the site planned to implement a new activated sludge process plant that would extend beyond its site boundaries. However, when planning permission was rejected for this, Hooe WwTW required an alternative solution with a small enough footprint that would fit inside the compact site’s perimeter.
Following a competitive bid, VWT UK was selected and supplied a two-streamed AnoxKaldnes™ K5 system composed of prefabricated biochemical oxygen demand (BOD) and glass reinforced plastic (GRP) MBBR tanks, which included retention sieves, air blowers and medium bubble air grids. A prefabricated Multiflo lamella settler was also supplied from Veolia Water Projects, VWT UK’s sister company.
With the need for a short delivery program, VWT UK carried out the manufacture and testing of the system’s tanks offsite, significantly reducing the project’s total delivery and installation time. The congested site also led to the transportation of the prefabricated solution to the site by crane to reduce the impact of deliveries, haulage and traffic within the local area. Once on site, it was then commissioned by the VWT UK team, as part of the site-wide construction, installation and commissioning overseen by Southern Water’s Framework Principal Contractor, CMDP, a Costain MWHT Joint Venture. Due to the rural location of the site, VWT UK and CMDP liaised closely with local residents throughout the project to ensure any disruption to the nearby village was limited.
During the project, national COVID-19 restrictions also came into effect. Despite this, VWT UK mitigated this issue with limited close working, increased personal protective equipment (PPE) for all employees and remote working where possible.
The AnoxKaldnes™ K5 MBBR plant has produced excellent rates of phosphorus and ammonia removal. It is difficult to think of another plant that would be able to fit in the available space on site while still reliably treating up to 60 litres per second of effluent.
– Graham Lea, Principal Process Engineer, Southern Water