Biffa

One of the 80 or so sites in the UK that have gained EMAS accreditation is the Redhill landfill facility, located in open countryside bordering the southern outskirts of London. This waste disposal site is owned and operated by Biffa, part of the Severn Trent water utility company. It accepts around 1,000 tonnes of waste a day from nearby local authorities and from local waste management companies.

In 2000/2001, Biffa recorded a turnover of £396m, and a profit of £45.7m (before exceptional costs).

Redhill is an unlined 'dilute and disperse' landfill covering 65 hectares of former agricultural land. Between 1954 and 1992 it was quarried for the mineral known as fuller's earth. This left a void of around 10 million cubic metres, partially filled with water.

Planning permission for infilling and restoring the site was granted in 1989, and this lays down conditions governing the way the site is operated and eventually restored. For example, the types and volumes of waste to be dumped at the site are restricted, and extensive environmental monitoring is required.

The operation is regulated by means of a waste management licence issued under the Environmental Protection Act 1990.

As with most landfill sites, two environmental impacts are of particular interest to the regulators: first, leaching of polluted water from the site into local watercourses; and second, emissions of toxic gases and unpleasant odours.

Additional problems arising from landfilling of waste include noise, insect pests, and lorry traffic to and from the site.

'Burying waste in the ground will always have its problems, but it's a matter of minimising those problems,' says Robert Sanders, site manager.

The Redhill site features active gas extraction. Methane drawn off the decomposing waste is either flared or used to power two 1MW generators which export electricity to the national grid. In 1999/2000, more than 3,000 tonnes of methane were used for power generation, while a further 400 tonnes were flared.

The environmental management system put in place at Redhill puts great emphasis on monitoring. Groundwater quality is measured every month using a series of 11 boreholes around the site, while around 1,500 measurements a year are made of methane concentrations.

Trends in environmental performance at Redhill are not easy to deduce, since each annual environmental statement provides data only for the most recent year. However, comparing the annual statements from recent years reveals that:

• Between 1995 and 2000, the growth in on-site electricity generation turned a net electricity consumption of 111,000kWh into a net export of 14,500,000kWh;
• Over the same period, water consumption at the site has fallen by 63% and gas oil consumption by 35%;
• The percentage of methane gas that was used to generate electricity rose from 36% in 1996 to 80% in 1999.

The operators of the Redhill site, like other landfill companies, are sensitive about the issue of complaints. No clear trend is apparent in the number of complaints received. In 1998/99, a total of 18 were made, 12 of them relating to odour. In response to this, Biffa undertook further 'capping' of the waste as well as greater extraction of landfill gases. Whether it was attributable to these actions or not, the number of complaints about odour fell to just five in the following year.

'A lot of what the waste disposal industry does is seen through the eyes of 10 to 20 years ago,' says Sanders. 'Things have certainly changed now. If people complain, we visit them and hopefully appease them.'

Sanders believes there are sound business reasons for having EMAS certification - not least of which is a greater likelihood of winning large, lucrative waste disposal contracts.

He estimates that the work involved in compiling the annual environmental statements required under the terms of EMAS represents about a month of one person's time each year. The path to accreditation in 1996 was fairly straightforward, Sanders explains, since the site was already approved to ISO 14001, and before that BS7750 (the equivalent British Standard).

'Quite a lot of the information we needed for EMAS was already available to us, like energy usage and our response to complaints,' he recalls.

Biffa's most recent three-yearly environmental statement for the Redhill site was published in 1999, and verified by approved auditors SGS Yardsley.

To date, all the waste deposited at the Redhill site has been placed above the natural water table. This means that relatively small quantities of polluted water leach out of the waste and into watercourses.

However, plans are in hand to develop a new section of the site which has been excavated to 37 metres below the natural water level. Because of its much greater depth, more stringent safeguards against water pollution would be needed than elsewhere on the site, including a composite lining system constructed from clay and high-density polyethylene. Discussions are currently under way with the Environment Agency over the details of this proposal.