24 September 2020
Green Party Press Release
Cambridge Green Party submission to the Phase 1 consultation for the Cambridge Waste Water Treatment Plant Relocation (CWWTPR) project.
Thursday 24th September, 2020
The Cambridge Green Party response was put together by Ellie Crane; long-term Green Party member with a background in ecological science and environmental and farming policy.
It appears from the project documentation that the main purpose of the CWWTPR project is to free up land for housing development in North East Cambridge. The local Green Parties believe that the scale of development planned for our region is unsustainable and we have significant concerns about the plans for North East Cambridge.
Our preferred option would be for the water treatment works to stay at its current location.
Assuming, however, that the CWWTPR project is going to go ahead, we would like to take the opportunity to comment on the proposals. We are aware of local campaigns raising specific concerns about one or more of the three shortlisted sites, and trust these concerns will be taken into account as the project moves into its next phase.
As representatives of the local Green Parties we do not have a preferred site out of the options put forward, but we wish to raise some general points and questions.
Thank you for the opportunity to comment.
1. Implications of the project for the River Cam
The ‘Let it Flow’ report, published by the Cam Valley Forum in May 2020, highlights the serious problems that exist because of over-abstraction of water in the Cam Valley. Groundwater abstraction currently deprives the Cam of about half its average natural flow. The ecological impacts of low flows are exacerbated by pollution, including nutrients from treated sewage. The impact of pollution is magnified when there is less flow available to dilute it. It is not yet possible to say whether future climate change will worsen or improve the situation, but it is clear that the resilience of the system needs to be improved.
The Cam Valley Forum puts forward a number of recommendations and proposals. They state that it would be desirable to upgrade treatment standards at all the sewage treatment works that discharge water to Chalk streams, in particular to remove nutrients from their effluents.
They also call for an evaluation of the feasibility and cost of treating wastewater to high standards, at all sewage treatment works in the Cam Valley, so that it can be used for public water supply, to recharge the Chalk aquifer directly, and/or to irrigate crops in locations where the contribution of treated effluent to summer river flows is not critical.
How will Anglian Water address these concerns and proposals through the CWWTPR project?
2. Production of energy and biosolids
In the Site Selection Technical Summary, it is stated that the current water treatment site includes a sludge treatment plant. Solids are passed through an anaerobic digester, generating energy that helps to power the site. The process also produces biosolids used by local farmers.
Green Party policy places a high priority on returning biodegradable organic waste, including sewage, to the soil. To achieve this safely, it is necessary to separate sewage from non-biodegradable materials (such as heavy metals). Our policy also proposes that water companies could be required to enter into joint arrangements with Regional Waste Disposal Authorities to build digestion plants to produce biogas and/or compost from organic waste from agricultural sources, sewage and municipal waste.
Will the proposed new facility increase (or at least retain) the capacity to generate energy and biosolids from anaerobic digestion? What measures will be in place to ensure that organic material applied to soil is not contaminated with non-biodegradable materials such as heavy metals and microplastics? Are there any implications arising from the choice of site (for example varying costs of transporting the biosolid to the fields where it is to be applied)? Has the potential for joint AD facilities with waste disposal sites been explored?
3. Loss of Green Belt
Green Party Policy strongly supports retaining and enhancing Green Belts. We do however recognise the case for siting the new facility at one of the locations within the Cambridge Green Belt, rather than at one of the sites further away from Cambridge.
In particular, we agree that the higher carbon emissions and greater risk of impacts to Principal Aquifers associated with the more remote sites are strong arguments against them. We note that Government guidance provides that “Where it has been demonstrated that it is necessary to release Green Belt land for development, strategic policy-making authorities should set out policies for compensatory improvements to the environmental quality and accessibility of the remaining Green Belt land.”
Green Party policy similarly encourages local authorities to review their green belt on a periodic basis as necessary to achieve sustainable development, with reviews seeking to ensure no net loss in the quantity and quality of green belt land.
Will Anglian Water work with local authorities to ensure any loss of Green Belt land as a result of the CWWTPR project is compensated for by improvements to the remaining Green Belt?
4. Preparedness for impacts of climate change
We note that areas classified by the Environment Agency as currently being in flood zones 2 or 3 were ruled out as potential sites for the new facility. However, as stated on Anglian Water’s website, projected impacts of climate change for our region include increased flooding and a greater chance of extreme weather including intense rainfall events.
Projections of sea level rise indicate that a significant proportion of the area north of Cambridge will be below the annual flood level by 2050. These impacts clearly have implications for the new water treatment works. As well as potential risk to buildings and infrastructure from flooding, there is a risk of raw sewage entering river systems if sewage works become overwhelmed during rainstorms (as has happened in the catchment in the past).
What is the expected operational lifespan of the new facility, and what assessment has been carried out of potentially increased risks due to climate change within this period? Are these risks substantially different across the alternative sites proposed?
1. Cambridge Waste Water Treatment Plant Relocation Project: Site Selection Technical Summary (2020)
2. ‘Let It Flow!’ (2020) Proposals from the Cam Valley Forum for an Integrated Water Resource Management Plan for the Cam Valley. Available online at:
3. Cambridge Waste Water Treatment Plant Relocation Project: Site Selection Technical Summary (2020)
4. See for example Marine and Coastal Policy MC402; Pollution Policy PL429; Food and Agriculture Policy FA640. All available at:
5. Natural Resources & Waste Management Policy NR413. Available at:
6. See for example Countryside Policy CY562; Local Planning & the Built Environment Policy LP407. Both available at:
7. Advice on the role of the Green Belt in the planning system (2019). Online at:
8. Local Planning & the Built Environment Policy LP510. Available at:
9. Cambridge Waste Water Treatment Plant Relocation Project: Site Selection Technical Summary (2020)
10. Anglian Water - Climate change
11. Climate Central – land projected to be below annual flood level in 2050. Interactive map available at:
12. Let It Flow!’ (2020) Proposals from the Cam Valley Forum for an Integrated Water Resource Management Plan for the Cam Valley. Available online at: