Gasworks site – are contamination issues being properly addressed?
The development of the Gasworks site on the cliff top above the Marina raises lots of important issues, some of which we have addressed in recent articles on this website.
The potential risks arising from extensive on-site excavations are one of those issues.
Developer the Berkeley Group is currently involved in eighteen gasworks site redevelopments all over the country, in a joint venture between the Berkeley Group and National Grid. Another thirteen are in the pipeline.
Map (courtesy of the Berkeley Group) showing the eighteen gasworks sites. Interestingly it fails to show the Berkeley/St William site at Southall where health issues have been reported (see below). Have they something to hide? They also changed the name of the Southall site from “Waterside” to “The Green Quarter”. It would be interesting to find out why.
On a few of these sites, construction work has already started. The scheme at Southall Middlesex referred to above, is a huge development of 4,000 new dwellings. Local residents have reported experiencing a number of severe health issues and odours, which they believe were due to their exposure to toxic chemicals released from the ground by excavations on the site.
Berkeley are also involved in another Gasworks redevelopment at Lea Bridge in Leyton north London, for 575 new dwellings in ten buildings up to eighteen storeys tall. A six year construction programme is envisaged.
In Brighton the construction stage will take at least eight years according to Berkeley. And developers’ initial forecasts are usually optimistic, so we could be looking at possibly ten years or more of disruption and potential contamination effects.
Yet another site is in Hornsey where a development of 281 new homes recently received planning approval. Residents have complained about exposure to strong noxious odours, that they believe are toxic, both outside and inside their own homes.
And there is another Berkeley project in Bow where fourteen towers to create 1286 new homes are planned.
A coalition of residents with similar concerns about developments on the following gasworks sites have joined forces to establish a group called Gasworks Communities United (GCU). They are demanding an urgent overhaul of regulations on the treatment of contaminated land to protect people’s health and wellbeing.
GCU’s members are:
CBC at Lea Bridge, Leyton
CASH at Southall & Hayes
AGHAST at Brighton & Hove
The Friends of Tower Hamlets Cemetery Park – Bow Common
Hornsey residents – Clarendon Road Gasworks
Worthing Residents – Worthing Gasworks
Gasworks Communities United say that toxic land remediation practices must be independently assessed as part of any new redevelopment, and demand a swathe of regulation changes in the way that contaminated land is managed.
There are two important issues here.
The first is how best to identify and analyse the risks to health from potential contamination which could be released by invasive excavations for foundations and services during the construction stage, and to determine what measures would be necessary to protect the health and well-being of residents living and working in adjacent areas of the city
The second is to examine how the design of the new housing could respond to those risks by minimising the amount of excavation required – and minimising the risks too.
Berkeley’s proposals appear to be very weak on both those counts.
Contamination risks
An Environmental Impact Assessment (EIA) scoping report prepared by Quod, a specialist consultancy for Berkeley/St William, acknowledges contaminants on the site, envisages a construction period of eight years, and requests that human health considerations be left out of the scope of consideration.
This hardly inspires confidence in the process proposed by Berkeley.
The Berkeley Group falsely asserts “that odour is different to air quality and does not mean it is harmful to health, or that mitigation measures are not being effective“.
This is directly contradicted by Professor Watterson, an Environmental & Public Health expert in gasworks remediation at the University of Stirling, who writes:
“The effectiveness of such engineering solutions and materials used in remediation or containment may not become clear for several years or decades. Each decade produced new risks and new risk assessments that had not been factored in at the time of the original reports’ publication. Each time, the risks identified often grow and the measures that need to be taken have to be strengthened. Very low level exposure to mixtures for example was not on the radar of brownfield risk assessments decades ago nor were ultra-fine particles, endocrine disruptors with impacts at ppt or even PM2.5 If consultants and others – citizen toxicology – report visual and olfactory signs of hydrocarbons etc on a gas site that ceased activity decades ago, it is a cause for concern.” NB : ppt is Parts Per Trillion
And erring even more on the side of caution, the World Health Organisation states that “There is no such thing as any “safe” level of exposure to some of the toxic chemicals that may be found in such sites.“
Has the Council any expertise?
It is certain that the Council does not have the in-house expertise to be able to judge whether Berkeley and its consultants’ contamination strategy is adequate to ensure public health concerns are properly dealt with.
Nor has it the funds to employ an independent specialist to vet Berkeley’s proposals.
In our view it must select its own expert consultant and require Berkeley to underwrite the cost of an independent report. It is equally important that the decontamination and construction procedures – including preliminary exploratory excavations and work – are independently supervised and monitored – just as a Clerk of Works would supervise the construction quality of the building work.
Given the problems at Southall in particular, it is vitally important that this question is subject to the most exacting standards of independent review and evaluation.
Design to reduce contamination risk
How might the design and layout of the new housing achieve this? Reducing risk to zero is a technical challenge. And like many technical challenges things can and do go wrong on the way, as we can see from the Southall example. But the risk factor can be significantly reduced by taking a different approach to design.
Rather than trying to maximise the development potential of the site by building tall blocks of flats requiring deep and invasive excavations and piling, why not try to reduce the excavations to the absolute minimum?
This in principle would mean “floating” a concrete raft upon which each building (or group of closely located buildings) would rest. Spaces between the buildings would then need minimum groundworks to seal in the contaminants. It would be virtually impossible to remove all the contaminants anyway. They would run deep, carried far below ground by water flows over the last hundred or so years.
This raft would support low-rise high density lightweight structures up to about four storeys or so high. There are several recent housing schemes which use lightweight engineered timber (CLT) structures for buildings considerably higher than 4 storeys.
Nick Hibberd, Executive Director of the Council’s Economy, Environment and Culture section should know all about these techniques as like us, he attended a Construction Voice seminar on 29 January 2020 in which Tom Westwood of Waugh Thistleton Architects, described and illustrated examples of large timber residential buildings in Leamington Spa and and East London.
Here in Brighton there is one in Lewes Road too.
Use of modern CLT techniques would be a very sustainable, very low carbon solution which would fit perfectly with the current Council’s Green Agenda. There are other similar sustainable systems available using MMC (Modern Methods of Construction), techniques.
Why is the Council not actively promoting these systems?
If it really believes in its green agenda, why is it promoting the huge concrete structures and piled foundations proposed by Berkeley which are totally the opposite – outdated and highly carbon intensive construction?
Use of modern construction methods would result in a building form, height and scale much more sympathetic to the adjacent residential areas including the nearby conservation areas and listed buildings, and be far less intrusive visually, given the Gasworks site’s prominent position on the cliff above the Marina.
Low-rise buildings around a courtyard can accommodate very high densities – and provide comparable numbers of new dwellings to high-rise blocks. The diagram below illustrates the point.
Council’s Response to the Scoping Report
The Council’s opinion report dated 20 Nov 2020 suggests that though building heights have not been finalised as yet, they are likely to vary between 4 and 17 storeys. It anticipates dust falling on land up to 500m from the site and an eight year construction period.
That would include large areas of eastern Brighton and a very large area of the South Downs National Park (only 70m to the north).
It would also include The East Cliff and Kemp Town Conservation Areas which are about 100m to the west, the Grade II listed Kemp Town Enclosures Registered Park and Garden (250m), the Grade 1 Listed Sussex Square (170m), and the Brighton to Newhaven Cliffs SSSI (50m).
The opinion report suggests that an Environmental Statement (ES) will be required.
This would include the following topics:
• Socio-Economic Impacts
• Transport
• Air Quality and Odour
• Noise and Vibration
• Daylight, Sunlight and Overshadowing
• Ground Conditions and Contamination
• Townscape, Heritage and Visual Impacts
• Biodiversity (to include a Ecological Impact Assessment (EcIA).
• Water Resources, Flood risk and Surface Water Drainage
• In-Combination Effects – eg noise impacts alongside air emissions and contamination on a sensitive receptor such as protected habitat.
The Council’s Public Health Team have recommended that the following matters be included in the planning application and should inform the ES:
• Refer to the Joint Strategic Needs Assessment & B&HCC Health and Wellbeing Strategy
• Undertake a Health Impact assessment (HIA) for the Planning Application.
• Use data from Community Insight Use data from Community Insight where you can find specific information on the Rottingdean Coastal Ward.
Identified dust and surface soiling could include contaminated material and gases and odours could be released. This should be addressed in the ES.
Noise and vibration issues resulting from piling and or other construction activities should be set out.
The Council Heritage Team have requested that the historic wall along the western edge of the site be considered an undesignated heritage asset and added to the list of assets in paragraph 12.7 of the document, due to its origins as the wall defining the boundaries between Brighton and Rottingdean.
Natural England has set out that the ES should consider the effects on the SDNP, local landscapes and heritage landscapes.
This summarises the Council’s position. There is a lot of work to be done to ensure that evidence to justify this development responds satisfactorily to that long list of qualifications and requirements.
The planning process is being done in the wrong order.
Alternative approaches to developing this site should have been done and publicly discussed right at the very beginning.
But Berkeley have unilaterally pre-empted this possibility by spending a lot of time and effort coming up with a massively overdeveloped scheme which closes off a low-risk, low cost, low rise option.
That’s their problem.
There is a much more satisfactory solution – if only the Council would take on board some of the ideas set out in this article and seriously re-consider the risky strategy it is currently pursuing.
The community demands it.
That’s the Council’s problem.
