When is disposal of liquid waste underground not a discharge to groundwater? When it is a landfill operation. When is the disposal of liquid waste underground not landfill? When the waste is solid but in a ‘liquid carrier’. Those are the complex conclusions to be drawn from a nine-year saga which has just ended with the closure of a Lincolnshire waste business.
Blackland Park Exploration Ltd (BPEL) runs an oil well in Whisby, Lincolnshire, which produces some 25 tonnes of crude a day. Along with the oil comes several hundred tonnes of produced water, which are re-injected into the well.
The well is 3,000 feet underground and the Environment Agency has accepted the re-injection is no risk to groundwater.
Until recently, BPEL has been using the re-injection process to dispose of aqueous industrial waste. This was covered by a waste management licence obtained in the early 1990s.
When the Landfill Regulations 2002 were introduced to implement the 1999 EU landfill Directive, the site was classified as a hazardous waste landfill. The Agency began a process to stop the disposal of the liquid waste at the site which had been made illegal.
At this point, the company disputed that the operation was landfill. Instead it said the operation should be regulated under groundwater regulations and it applied for a groundwater consent. But the Agency refused to accept the application and even declined to cash a cheque for the fee, company director Geoff Dickinson told ENDS.
The Agency took the case to the High Court in 2003. The court decided that because the operation was one of waste disposal, the underground strata could indeed be regarded as a landfill site (ENDS Report 343, pp 51-52 ). The BPEL took the case to the Appeal Court later that year but lost.
The disposal of hazardous liquids was stopped at the site in July 2004.
BPEL then took its case to Brussels, to be told by the European Commission that its activities could be regulated under either water or waste legislation, but that member states had the freedom to interpret the legislation themselves. By this time the Agency had issued a closure notice on the site’s waste operation.
The company approached Environment Secretary, Hilary Benn, late last year asking the government to exercise its discretion in the company’s favour. It drew attention to another case where this discretion seemed to have been granted. This was the disposal of liquid wastes from a chlor-alkali process in Cheshire, where brine wastes are pumped into salt caverns for disposal.
Ineos Chlor mines brine by injecting hot water into salt deposits near Northwich. The brine is sold to Brunner Mond which uses the feedstock to produce sodium carbonate via the Solvay process.
The wastes, still dissolved in brine, are returned to Ineos Chlor for reinjection into the caverns formed by the extraction process. The operation is covered by a waste management licence, even though the regulations prohibit landfilling of liquid wastes.
Although the wastes - calcium chloride and carbonate plus impurities present in the original brine solution - are innocuous, BPEL reasoned they were the result of an industrial process and there was little difference between its own operations and Ineos Chlor’s. Neither was causing damage and both might be regarded as the best practical environmental option.
But the minister wrote to BPEL on 26 January with the following explanation: "The operation at Ineos Chlor involves the underground storage of non-liquid waste, with brine being used as a liquid carrier of the non-liquid waste: the brine is not classified as a liquid waste. By contrast, the Whisby site involves the landfilling of liquid wastes."
Clearly some double-think is required to understand this argument. But the Agency’s Lincolnshire area manager David Hawley suggested that an important difference was that Ineos Chlor was not actually importing waste onto the site as BPEL was. The situation was analogous, he suggested, to BPEL’s re-injection of produced water which had never been disputed by the Agency.
The argument would be stronger if there was only one firm and one site involved in processing the brine.
"What BPEL wants to do is simply not possible in the current legal framework," Mr Hawley said. "In some cases it might be a good idea to put waste down holes in the ground. It’s definitely the cheapest option. But recovery might be a better idea, which is what the landfill Directive is all about."