A row between the Health and Safety Executive (HSE) and Transport for London (TfL) over risks posed by a chemical site is threatening the Silvertown Tunnel scheme.
Transport secretary Chris Grayling will make a decision on whether to grant planning permission for the east London tunnel in October, but the HSE has come out against the scheme. This is because parts of the tunnel would run close to a potentially hazardous chemical storage and distribution site, called Brenntag Inorganic Chemicals.
In 2012 a blaze broke out at the chemical plant, triggering an air raid siren alert to nearby residents due to the danger posed by the stored chemicals, according to a report in the Evening Standard.
The HSE believes there is an increased risk to the public if another such incident occurred at the chemical site, as there could be stationary or slow-moving traffic in the tunnel, if built.
Silvertown Tunnel map
Source: Transport for London
In a letter to the planning inspectorate, the HSE has argued that proposed works to the A102 tunnel approach, which is to be widened from five to eight lanes and would link with the A1020 on the north side of the Thames once the tunnel is complete, could increase the number of people at risk by around 10%.
Therefore, the HSE is advising that a “Grampian-style requirement” be attached to any development consent order (DCO) granted – meaning that the tunnel could not be opened to the public unless the chemical site no longer posed a risk. A Grampian requirement would prevent the start, use or occupation of a development until certain conditions have been met by the applicant.
But TfL says any such requirement would present “a significant risk to the project and its procurement”. It is lobbying Grayling to ignore the HSE’s advice, arguing the safety body is being over cautious.
“As was made clear in TfL’s examination submissions [to the Planning Inspectorate], TfL considers that the HSE’s position is based on an overly-restrictive methodology that is being applied too narrowly in the context of the scheme,” said a letter to Grayling on behalf of TfL.
TfL argues that by managing demand – it has previously said the road could be tolled – there would be fewer people exposed to risk than estimated by the HSE. More road capacity would result in smoother traffic flow, and therefore vehicles would spend less time exposed to risk.
The transport body believes its evidence previously submitted to the inspectorate gives Grayling sufficient cause to ignore the HSE’s advice.
“TfL considers the evidence and analyses it submitted during the examination provide sufficient grounds for the secretary of state to override the HSE’s advice when determining the DCO application,” states the letter.
“Accordingly, TfL believes a Grampian-style requirement is unnecessary and disproportionate in response to the risks associated with the Brenntag site and the modified A102.”
TfL added that if the HSE had considered the development an extension to an existing road rather than a new highway, it may not have advised against the scheme.
A spokesperson for HSE said: “HSE has actively been involved in the planning process for the Silvertown Tunnel. We recognise this is an important infrastructure project.
“This correspondence reflects the detailed and important work we’ve been doing with the Local Planning Authority and TfL.”
The Department for Transport said it would be innapropriate to comment further.
TfL is currently looking for a contractor to design, construct, finance and maintain the 1km twin-bore Silvertown Tunnel.
In March, TfL announced three bidders, Ferrovial-owned Cintra Global, Hochtief PPP Solutions and Strabag/Skanska, as its shortlisted contractors. A preferred bidder for scheme is expected to be announced next spring following a decision on the DCO in October.