Woolston construction

Work is under way on our redevelopment and modernisation of Woolston Wastewater Treatment Works.

We started work in September 2014 and expect the construction process to take about five years to complete. 4Delivery (4D), a consortium comprising Veolia Water, Costain and Stantec, is carrying out the work on behalf of Southern Water.

The project is being carried out in stages to make sure we can continue to treat the wastewater for the local area while the redevelopment is being done, and because of the very small area of the site which we can work in.

We built a temporary treatment works which took over much of the treatment from the existing works during the main construction phases. This enabled us to start work on the existing site by demolishing some tanks and structures.

Update – August 2018

June 2018 saw us reach our third significant milestone – starting to pass wastewater through some of the new secondary process equipment, specifically the membrane biological reactor (MBR) which is the largest wastewater MBR of its kind in the UK.

By turning the flows into this new secondary treatment process which completes the second stage of cleaning the wastewater, we’re now able to move on to decommissioning, cleaning, and removal of some of the temporary treatment works from now on. Demolition will be required over the course of the next few months.

We’re well underway with erecting the steel framework that will support the new buildings. Cladding to the building framework starts in late summer and will be finished in winter 2018. These superstructures enclose the primary, secondary and sludge treatment processes and form an odour and sound barrier between us and our neighbours.

Update - November 2018

We have diverted incoming wastewater through the next new stage of process. The full flows are now processed entirely through the new plant and local residents will benefit from a reduction in odour sources because of a more efficient screening and treatment process.

Construction of the sludge treatment area has made speedy progress, with the building’s steel frame being erected during August and the concrete bases made ready for installation of the sludge process plant and storage tanks during the next few weeks.

Our specialist contractors will continue to build the steel framework for the sludge building, moving on to start placing the roof and wall cladding on the main buildings during October.

We’ve been making steady progress removing redundant pipework and equipment from the enabling works temporary treatment works area.

We will move on to demolition of the redundant tanks and structures in the original treatment works site once they have been cleaned. The cleaning operations are likely to generate odours when residual sludge or screenings are disturbed – please bear with us whilst we carry out this essential activity.

The new sludge treatment process is expected to be up and running during spring 2019.

Recent changes

In January 2018, as part of bringing the plant into service, we ‘turned flows’ and started to pass wastewater through new treatment processes. The means you may hear new noises coming from site – don’t worry, we are also monitoring this.

In January 2018, as part of bringing the plant into service, we ‘turned flows’ and started to pass wastewater through the new primary treatment process. The means you may hear new noises coming from site – don’t worry, we are also monitoring this.

Where possible, we have been using additional acoustic screening alongside the manufacturer’s noise covers. We’ll continue to monitor the sound experienced at the site boundary and do what we can to try and reduce these.

Over the next few months we’ll be continuing with the commissioning and optimisation of the new equipment, which will cause some fluctuations in the noises you hear from the site.

We apologise for any inconvenience this may cause and thank you for your patience. As more of the new site is brought into operation over the coming months, we anticipate there will be more changes to the noises you might hear, alongside construction noise.

When the site is finished in Summer 2019, the new process equipment will be contained within a new building, which is due to be completed during Spring 2019.

This building will significantly reduce the amount of noise you hear from the process plant.

We’re doing everything we can to minimise disruption during this redevelopment. Things on site are progressing quickly and we’ll continue to monitor the impact of these changes on our neighbours.

We’d like to thank you for your patience during these works and welcome any feedback you might have on how we could do better, please use the contact details below or speak to one of the site team directly.

If you have any further questions, please contact Southern Water’s customer call centre on 0330 303 0368, quoting the site PRN reference 539389. Alternatively, you can contact the 4D Woolston Site Office on 023 8042 0856.

Construction FAQs

There will be temporary increases in the number of vehicles travelling to and from the site, but traffic management measures will be put in place to ensure that this causes as little disturbance as possible. We will consult with other developers working in the area to ensure that there are no conflicts with traffic.

During construction, access to the site will be from Victoria Road, either through the existing compound entrance next to Crest Nicholson, or via the new entrance to the treatment works opposite Swift Road junction.

We’ll do all we can to keep noise to a minimum. The noisiest part of the scheme is likely to be the demolition of the redundant temporary treatment works.

Hydraulically-operated plant will be used where possible to minimise vibrations arising from sheet piling works, however, if we meet ground conditions that do not allow us to use this method, we will need to use other techniques.

Bored screw piling is the preferred installation method where ground conditions allow. Again, where there are technical reasons why this is unsuitable, we will need to look at alternative methods.

Any dust coming from activities on site will be reduced using water sprays, the wheels of vehicles leaving site will be washed and road surfaces cleaned to keep the surrounding area as clean as possible.

All works relating to construction of the development will only take place between the following hours:

  • Monday to Friday 8.00am–6.00pm
  • Saturdays 9.00am–1.00pm
  • At no time on Sundays and recognised public holidays.

Deliveries to the site during the construction phase shall avoid peak traffic hours of 7.30-9.30am and 4-6pm unless agreed with Southampton City Council.

We will not need to enter your home at any point during these works. Should someone come to your address claiming to be from the works and requiring access, please close the door and call the police on 999. Remember to always know the identity of doorstep callers.

Works connected with the ongoing operation of the treatment works will continue as usual and there may be activity out of normal working hours arising from emergencies on site.

Parking for vehicles connected with the works will be provided in the currently unused section of the Victoria Road car park. Provision for any additional parking will be agreed with Southampton City Council.

We have liaised closely with Natural England and the Environment Agency and have carried out environmental surveys to assess impact on wildlife.

Robust mitigation measures will be put in place during construction and these are included in the planning consent.