Siltbuster, the leading water treatment specialist, has provided Costain with four modular treatment solutions, to be used during the delivery of the £200m Preston Western Distributor Road, linking Preston and southern Fylde to the M55 motorway.
The 2.5 mile-long dual carriageway, set to open in 2023, includes a new motorway junction, four new bridges and three underpasses. The route goes past several surface watercourses, including the Savick Brook and the Lancaster Canal. With this in mind, Costain contacted Siltbuster at a very early stage in the project and tasked it with planning the water runoff management.
To date, Siltbuster has deployed four water treatment systems to cover the multiple controlled watercourses where water is being released from the site. Each location is regulated by the Environment Agency, with the Environmental Permit requiring total suspended solids be less than 100mg/l and a pH value between pH6 and pH9 to be achieved consistently.
In order to protect the north west’s aquatic ecosystems and habitats, each Siltbuster unit needed to be capable of treating flows of up to 40m3/hr. To deliver this, all of the systems include two-stage flow proportional chemical dosing of coagulant and flocculant to improve the settlement rates of the very fine suspended clay solids, and an 8m3 tank complete with mixers and a HB50 lamella clarifier. The modular nature of these solutions means additional capacity can easily be added should the coming wet season create greater volumes of water needing to be treated.
Karl Heath, Environmental Manager at Costain, comments on its water treatment approach: “We’ve been managing the water on site throughout the project starting with basic settling techniques. By engaging Siltbuster early in the process we could make sure we were ready to deploy more advanced systems when it became necessary at the end of the summer, in preparation for the wet season and the consequent increased surface water runoff. The Siltbuster systems have helped keep the project on track by ensuring we are in line with our environmental permit at all times, protecting the surrounding habitats as vigilantly as possible.”
James Baylis, Regional Technical Sales Engineer at Siltbuster, concludes: “It is to Costain’s credit that it consulted with us early in the planning stages of the project. We were able to advise on temporary flexible modular solutions which could be rapidly deployed from our hire fleet as soon as the need arose. As part of our service, we have also offered Costain specialist technical advice and training, helping to protect the aquatic ecosystems around the project.”