Local government can be extremely glamorous some times and as such I spent Monday afternoon visiting the Swalecliffe Sewage Plant in Brook Road. I was asked to attend by Southern Water as part of a small stakeholder group, including representatives from SOS Whitstable, environmental groups and local residents in close proximity to the site. The group was convened following the public meeting arranged by Rosie Duffield MP at the end of June.
Detailed communications about what is going on at the plant will be coming out soon and whilst I am not a water engineer I thought it would be useful to share some reflections on the trip and what hope there is for the future.
So what do we know:
- Investment has started at the site
Concerns by direct neighbours about being woken by an alarm every time a ‘spill’ took place have been addressed by now manning the site 24/7. Inspections of the Odour Control Unit on site have identified a number of broken pipes which have been replaced and there are now odour monitoring stations run by an independent company on site and in the back garden of one local resident. We are pushing for real time information from this system to be available to local residents.
We saw evidence of new electrical back ups added to the inflow coming into the site, additional storm tanks to increase their overflow capacity and plans for new improved systems to remove ‘rag’.
Southern Water are using the odour monitoring system to manage the effectiveness of the Odour Control Units and how they pump out the tanks. Five times a week ‘sludge’ (the removed faecal matter) is transported to another site in Canterbury where it is processed into bio gas and a nitrate rich fertiliser sold to farmers.
The company have already invited local residents to visit the site and residents reported that communication has notably improved. Evidence of improved communication includes an agreement by Southern Water to replace the gates on site (they were loud at night), cut back trees and consider introducing an ANPR system which would automatically open the gates, improved signage and avoiding collection during the school run to improve road safety.
At the end of this month the company will seal the outflow into the Swalecliffe Brook used to as an emergency pressure release valve when heavy rain reaches the hydraulic capacity of the site. The site is currently designed to take 208 litres of sewage a second but can reach up to 800l per second in heavy rainfall.
When the 208l capacity is met, large storm tanks on the site fill. This water is then pumped back into the system when the pressure dissipates. If these storm tanks are full to bursting, water is currently pumped into the brook. From November this now be disposed of by the short sea outfall – the diluted sewage released into the sea but not the SSSI.
Southern Water have increase the capacity of their storm tanks by 25% to try to try and reduce the number of times capacity is reached.
The proposed extension to the long sea outfall – the pipe with which cleaned water is pumped out to sea will take place in Summer 2024. The work can only be done outside of the season for migratory birds and requires a number of licenses for off shore piling. They have submitted a planning application to the council for the new base of this on the shoreline.
They have offered to help clean up or ‘rewild’ the Brook after the building work but how the systems were allowed to fall into such disrepair still remains unclear.
2. Water quality testing is the next battle
Whilst works have started on the Swalecliffe site, Southern Water are clear that the problem of surface run off overwhelming our Victorian sewage system isn’t going away and is only getting worse with climate change.
The Swalecliffe pumping station serves a catchment of some 38,000 people and when the system predicts capacity at Swalecliffe is to extend beyond 800l per second – the overflow (surface run off and untreated sewage) is directed upstream of the plant to one of 5 combined sewage outflows (CSO’s) along the coast.
Whilst water flowing through the CSO’s is heavily diluted and not raw sewage, the pertinent question is how safe its the water to swim in.
Southern Water currently provide real time data on the use of their CSO’s through an app called Beach Buoy. They acknowledge that this system needs improvement are are revising it. The new system will see spills effectively colour coded to more clearly explain to people the total quantity of water spilt, how tides will disperse flow and updated to prevent a number of false positives.
The system currently records when sensors in each of the pipes are triggered however on site inspections and modelling after the alarm can sometimes indicate that the trigger is seawater flowing up a pipe on the tide or a mechanical fault. Surfers Against Sewage are being consulted on how this information will present on their app.
Southern Water are at pains to suggest that recent community water testing which identified the presence of E-Coli at the beach is at odds with Environment Agency data which suggests our beaches have the cleanest water they ever. Whilst it would be nice for the community to be involved in testing, there are questions to be raised about the accuracy of these home test kits, whether capacity exists locally to do proper laboratory testing and how quick any turnaround would be.
The preferred solution would thus be a real time water quality monitoring station off Tankerton which Southern Water have indicated they are willing to help fund. We are actively pursuing this with the council and Southern Water.
3. House building is making the problem worse
In contrast to many of its competitors, Southern Water publicly wrote to MP’s this week in support of Duke of Wellington’s amendment to the Environment Bill.
This amendment (added to the bill twice by the House of Lords) committed water companies to reducing CSO emissions year on year – it was eventually replaced by a government amendment which only asked them to work to mitigate the effect of said emissions. The revised amendment prevented a back bench rebellion but was widely criticised by local environmental groups for failing to hold companies to account.
In our meeting Southern Water made it clear that the nature and scale of future house building was untenable unless the council are able to commit to all new developments being ‘water neutral’. The water neutral standard sees developers encourage homeowners to use less water by installing smart meters and mechanical devices to reduce water use. It encourages them to harvest gray water and include means of storing water on site so that it slowly soaks through the catchment and doesn’t rush immediately into the drains (semi permeable tarmac, attenuation ponds, soakaways and reed beds).
Whilst we have recently forced the council to review its approach to sustainable drainage, we are actively pushing Southern Water to make a public statement to this affect but we have launched a petition for the council to adopt the ‘Water Neutral’ standard which you can fill in here.
We are also exploring how the council might use its building control function to ensure housing already in the pipeline is designed to this standard. Maps are being made available for the catchment so we can see the impact of planned development in the new Local Plan.
4. A new partnership approach is needed
Southern Water have began modelling and physically surveying the catchment across Whitstable to discover where surface run off is worse and what can be done about it. There initial calculations suggest that 50% of the surface run off comes from roads and 20% from roofs. Reducing this figure by 17% reduction would reduce CSO usage by over 80%.
Of course reducing surface run off from roads and homes is not easy but there are ways to do it. Additional drainage channels could be built near roads, smart water butts added to homes to hold water and funding made available for grey water harvesting on large industrial roofs.
In order to be able to put in a concerted plan, Southern Water are offering to help initially convene a North Kent Water Partnership with representatives from Kent County Council, planning authorities, the Environment Agency and Natural England. They are interested in bodies pooling funding to fund a concerted plan to reduce run off. The group would be independently chaired and see Southern Water contribute financially to any plan. How much any scheme would cost is unclear.
The stakeholder group are to begin regular meetings with Southern Water before Christmas and your opinions matter. If you have any evidence of a pollution incident or opinion on how we should proceed please email me at [email protected]
It’s fair to say that after this summer we all know a lot more than we did about sewage treatment and whilst it is encouraging to see some progress and open lines of communication, it is fair to say we remain sceptical.