Campaigners in North London are preparing to launch legal action against a proposed 789-home development on a former gasworks site, citing fears of contamination from toxic chemicals including cyanide, benzene, and asbestos. The Keep Kensal Green Campaign, which has been opposing developments in the area, is crowdfunding the legal challenge against the St William Kensal Gasworks Development, which was submitted for planning permission on July 25, 2025.
The site, formerly occupied by Kensal Gasworks gasometers, is being developed by St William, a partnership between Berkeley Group and National Grid. While the St William project is smaller than the nearby Ballymore development known as Project Flourish, residents and campaigners have raised similar concerns about health risks and environmental impact.
Campaigners cite health risks and toxic exposure
Jude Allen of Keep Kensal Green said: "I have so far found 30 other developments around the UK. A proportion of which have been done by Berkeley (the same developers as St William), where health impacts have been reported, the same journey of residents saying, hang on, we're getting sick. What's happening? The developer's saying, no, no, nothing to see out here. You were just being hysterical. But there is a growing body of evidence that this could be the cause."
Allen also highlighted concerns about traffic during the 10-12-year development period, stating that more than 100 lorries a day would carry toxic waste along major arterial routes, including Harrow Road. "St William wants to remove their toxic waste by lorry or container, going through residential areas and taking the route via Harrow Road. They are taking it to what's called a soil hospital and piling it up there," she said. "It's just horrendous. So, not only have we got these toxic chemicals going into the atmosphere, being carried seven kilometres into Westminster and Brent, we also have, from Ballymore, actual toxic waste will be taken along Harrow Road in 100 lorries a day."
The campaign group also raised concerns about short-term health effects for residents, including headaches, itchy and streaming eyes, nausea, and a tight chest, from inhaling benzene, naphthalene, cyanide, and asbestos. They also noted the potential for unexploded bombs from the Blitz to be found during foundation work, as well as impacts on the listed Kensal Green Cemetery and a lack of affordable housing.
Councillors express fears and call for caution
Liberal Democrat Cllr Barbara Want, representing a neighbouring ward in Brent, expressed significant concerns about the development's impact on her constituents. She told MyLondon: "There are lots of different reasons that people might want to reject to this application, but the one thing that stood is the fear of the health impact, you can argue forever the percentage of affordable housing and local infrastructure, but I don't feel in our ward that is the key issue. Having spoken to residents, there is an absolute genuine fear for the potential and release of toxic gas to the extent that I have parents who are saying they want to move away from here."
Cllr Want added: "The response was that this was scaremongering, but you do not scaremonger the fact that this is heavily contaminated land and that it is going to be excavated, and that history shows that trusting a council or a contractor is not a guarantee of safety. Have you seen Toxic Town?" She noted that although the development is in another borough, the contaminated soil would reportedly be transported through Brent, prompting her to raise concerns about the approval process.
Developers and council defend planning process
In response to the concerns, a spokesperson for the Royal Borough of Kensington and Chelsea said: "Objectors were given the opportunity to address the Planning Committee directly, and their concerns were carefully considered by members during the meeting. Having taken account of the development plan, all material planning considerations, the officer assessment and the representations received, the Committee resolved to grant planning permission, subject to the completion of a Section 106 legal agreement and referral to the Mayor of London."
The spokesperson added: "The Council has also imposed a range of planning conditions and secured planning obligations through a Section 106 agreement to ensure that appropriate controls, mitigation measures and other planning benefits are delivered as part of the development." Cllr Elizabeth Campbell, Leader of Kensington and Chelsea Council, called the approval "a major milestone for the borough," saying: "We have very little space to build in Kensington and Chelsea and a very high demand for housing, so it's absolutely crucial that the opportunity is grasped with both hands at Kensal Canalside. I hope it won't be long before the developer can get on with the job of building over 2,500 much-needed homes, 500 of those will be affordable."
Cllr James Husband, Chairman of the Planning Committee, said: "We gave detailed consideration to the application over almost three hours last night. The number of homes is very significant in the context of our borough and in the end the public benefit outweighed the harms. At a vote of four to one, the committee agreed to resolve to grant planning permission." Ballymore, which declined to comment on the campaigners' concerns, outlined benefits of its Project Flourish development, including 2,519 homes (500 affordable), two public parks, play spaces, biodiversity gain, and contributions to local amenities. Berkeley Group did not respond to the campaigners' concerns.
A planning decision for the St William site has not yet been made, with consultation having concluded and a decision due on October 8. Once Project Flourish files its Section 106 agreement, the Keep Kensal Green Campaign plans to launch its legal action.
