Liverpool Wastewater Treatment Works – Keeping the Mersey clean
A lot has changed in Liverpool over the past 25 years and one of the most remarkable changes has been the clean-up of the River Mersey.
On October, 4, 1991 Liverpool Wastewater Treatment Works was opened by H.R.H The Princess Royal, and nearly 25 years later Her Royal Highness, Princess Anne returned to open the new £200m state-of-the-art extension to the existing treatment works.
Lorne Large, United Utilities Principal Project Manager, said:
“The extension to Liverpool treatment works means we will be able to keep the River Mersey clean well into the next century.”
The latest development marks a far cry from when the River Mersey had reached its low point in the mid-1980s, when it was described by the then Secretary of State for the Environment, Michael Heseltine “as an affront to the standards a civilised society should demand of its environment.”
It was famous for being known as the dirtiest river in Europe, awash with a deadly cocktail of raw sewage and toxic chemicals. However, over the past 25 years United Utilities and its predecessor North West Water has spent billions of pounds overhauling the sewer network to help play its part in the clean-up.
The opening of Liverpool wastewater treatment works in 1991 had a huge impact on the river. Prior to being built, the city’s raw and partially treated sewage was being discharged directly into the Mersey and its tributaries.
The improvement in treating wastewater had an instant impact, helping the river Mersey to flourish once again, which was key to the economic regeneration of the city.
Ian Fullalove, United Utilities special projects manager said: “The opening of the £200m extension to the existing treatment works will help continue the environmental improvements we have already been making.”
In the first stage of treatment, the raw sewage goes into the primary settlement tanks for heavy solids to be removed. The effluent then goes on to the secondary treatment stage, in which the water enters 16 basins each large enough to hold 18 double-decker buses.
Here, oxygen and bacteria are added which treats the wastewater. This produces clean effluent which then goes into the River Mersey.
The success of the clean-up is evident. Beautiful creatures such as dolphins frolicking in Liverpool Bay are becoming a common sighting and a humpback whale was recently spotted flapping its distinctive pectoral fin.
Matthew Clough founder of Liverpool Bay Marine Life Trust said: “Other species enjoying the cleaner water include octopus, salmon, grey seals and large cod, which are being badly hit worldwide.
“We’re also seeing dolphin and porpoise recovery which is absolutely fantastic and even more evidence the clean-up is working.”
Economically the city has also benefitted from the improved quality of water in the river, which has encouraged the regeneration of land beside the river and its tributaries.
Power Plastics Ltd
Having been in operation for 25 years, Power Plastics offer a complete turnkey solution for the design, manufacture and installation of a range of structures. These are designed to suit the existing tank dimensions and meet the client’s expectation.
Power Plastics are certified for the design and the manufacture of their structures. The company has worked on a variety of projects with diverse clients, including Grafham Water, Liverpool Wastewater Treatment Works and Melbourne Water Treatment Works.
Premier Construction spoke to Phil Sellers, of Power Plastics Ltd, to find out more information on the company and its involvements with Liverpool Wastewater Treatment Works in particular. According to Phil:
“Power Plastics designed, manufactured and installed eight covers over the SBR tanks; these covers were aluminium and stainless steel construction with PVC removable roof covers. The structures also had an aluminium walkway to allow access into the covers.
“This project was the first time Power Plastics had designed a roof structure that could be assembled at one end of a tank and then pushed down the tank – this reduced the risk of working at height and also dramatically decreased the time spend assembling the structures on site.
“Power Plastics commenced the installation of the structures in October 2014 and completed our installation in March 2015 – this reduced duration was due to the design of the rolling roof and the offsite assembly of the roof structures into large sections which could be quickly assembled on site.
“The Liverpool structures were another first for Power Plastics as we designed an aluminium decking system which interfaced with our aluminium framed fabric structures; this gave Power Plastics the opportunity to show GCA and UU that Power Plastics have a range of products that allow for the covering of tanks with both fabric structures and aluminium access walkways.”
When asked what the company prides itself on, Phil replied:
“Offering the complete service to our clients and designing complex structures that fit first time. As a company, our first thoughts when we are awarded a project are ‘how can we design a structure that can be installed safely and quickly on site?’ We offsite assemble large sections of our structures in our factories to reduce risk and installation time on site.”