Avenue Remediation

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VSD AVENUE, a joint venture partnership between Volker Stevin, DEC and Sita Remediation are undertaking the Avenue Remediation and Landscaping Scheme in Chesterfield, Derbyshire. Their client is the Homes and Communities Agency (HCA).

Please can you describe the project you are working on?

This is a long-term project to clean up 98 hectares of some of the most contaminated ground in Europe. Situated between the A61 and the main midland railway line, next to the river Rother near the village of Wingerworth, the site was previously occupied by a coke works, colliery, power station, lime works and other industrial processes at various times. The coking works ceased production in 1992 and in 1999 there was a period of demolition; the above ground structures and chemical tanks were emptied and demolished, to allow access to the below ground contamination problems including hydrocarbons, heavy metals, cyanides and waste chemical products.

The total volume of material being excavated, processed and replaced is in the order of two million cubic metres, making the Avenue one of the largest remediation projects currently working in the UK. Every cubic metre of earth is being tracked and can be accounted for – in some parts of the site to a depth of 18m.

The key objectives of the remediation of the Avenue site are to deal with the contamination through on site treatment and to deliver a restored landform which will provide significant benefits for the local community along with the provision of environmental enhancement and a flood alleviation scheme protecting areas of Chesterfield from future flooding. Completion of the work is scheduled for the end of 2015.

How have you incorporated the Scheme into your site?

We fully support CCS aims and the Scheme is included on management meeting agendas. Details of the Scheme and its Code of Considerate Practice are explained to all our site staff and workforce – not only at induction, but also through annual re-inductions in order to refresh knowledge and ensure our commitment and compliance with the Scheme.

A dedicated Considerate Constructors Scheme Champion coordinates the Scheme on site, raising awareness through toolbox talks, distributing feedback on our progress and awards won, and ensuring every member of the team is able to take pride in what we have achieved together. Our CCS Gold Award certificate is displayed proudly on site along with Scheme posters at key locations.

We try to employ local people wherever possible, training them up through internal and external courses to improve their future employment prospects. This is also a way of letting local residents know what is going on at the site – workers see what we are doing and relay it to other people in the community, which helps to allay possible concerns and misconceptions.

Lorry access has been limited to only 3 or 4 per day to minimise disturbance of residents. We try to keep a low-key presence, using minimal hoardings and billboards so that when people drive past they don't necessarily see the site. We keep things as neat and tidy as we can, trimming back overhanging trees and shrubs.

Since the beginning of the project, what challenges have you faced?

One of the initial difficulties was objection and genuine concern about what was going to happen with this contaminated site that had lain dormant for years. Residents didn't want things stirring up and were very nervous about odours and smells, health, noise and vibrations.

There were two silt lagoons leaking into the groundwater and contaminating the river. The contaminants present included hydrocarbons, which had to be broken down using high levels of heat – a particularly energy intensive and costly process requiring bespoke equipment.

A wide variety of wildlife species were known to have made their habitats on and around the site, including lapwings, kingfishers, badgers, ducks, snakes, foxes and even deer. Expert knowledge was required in order to meet biodiversity standards.

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Silt lagoon

How have you been able to overcome these?

We have sought to bring the public with us through education and information. This has included going out to give talks to local groups including parish councils and schools and handing out DVDs, posters and brochures. We have also been interviewed by and featured in several local publications.

We hold quarterly meetings with regulators and members of the public on site here and invite them to the site for properly controlled visits and periodic tours of the site. By showing them what has been deposited here, how it was killing the environment and what we are doing to clean it all up, they usually leave here more enlightened and happy with what's going on.

Our website, maintained by on-site staff, provides air quality monitoring reports as well as project progress pictures and other documents. Technical questions on topics including noise, dust, odours and health impact are dealt with as a priority by a dedicated technical committee.

The most hazardous materials are taken from the waste lagoons and mixed with soil-borne hazardous waste, before being treated in the Thermal Desorption Unit (TDU). Feed materials for the TDU are tested for calorific value and then blended to ensure the most efficient combustion is achieved. The waste is put through a kiln at temperatures of up to 600°C to remove the contamination. The resulting vapour is then heated to 1,100°C, washed, filtered and treated to remove all traces of the chemicals, leaving only steam to be released from the exhaust stack.

We work closely with Derbyshire Wildlife – they have a big input on the existing wetland area and its maintenance. We use ecologists on site to advise with issues relating to particular species, particularly where it becomes necessary to relocate their habitats.

We sponsor two local football teams and a tree-planting scheme. School visits are conducted prior to holidays to highlight the hazards of construction generally and this site in particular.

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TDU by night

Could you detail a few examples of good practice you have put in place on site?

When we reached the milestone of 1million man hours without any reportable accidents, management placed a shipping order of piping hot fish and chips to celebrate and thank the workforce. We have since reached 1,000 days without a reportable accident.

Last year the entire workforce was invited to complete a comment card offering suggestions on how we could improve things in their working environment, with an entry into a prize draw for all completed cards. An excellent response rate was received and a wide range of comments listed and shared.

Senior managers give tours and talks to university students. We recently hosted a tour for a group from Sellafield who came to see how we are treating the contaminated materials. A safety poster campaign was held at a local primary school resulting in a cheerful 50m long mural on the hoardings in the car park to brighten up the day for workers. The winning pupils were given a tour, lunch and a presentation.

A team of local residents monitor odour levels and there are many air pollution-measuring stations. We maintain a visitors' centre at the southern end of site away from the operational centre. Local schools use the facility for fieldwork such as pond dipping.

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Any other comments?

Our commitment to the Scheme is demonstrated by the time we devote to implementing the required standards. All initiatives to support the local community, the workforce and wildlife will continue to receive the same high priority.

We are cleaning up over 100 years' worth of industrial contamination in just six years and will leave behind us an area that can flourish once again. The afteruse includes a 28 hectare development platform along with public open space, sports pitches and a nature reserve. A legacy which we can all be very proud of.