Irish meat plants began killing cattle yesterday as part of a special scheme to combat BSE.
They are committed to slaughtering up to 25,000 animals a week and may kill 750,000 cattle over the next six months, producing an agricultural waste mountain of unprecedented proportions.
There seem to be few alternatives to burning this material, which must be destroyed in a way that guarantees BSE infection cannot spread.
Anaerobic composting (in the absence of oxygen) could dispose of the animals but might not clear any infection. Burying the animals would be rejected by the public as a potential BSE risk to groundwater. Locals dug up and dumped a BSE-infected animal last October that was buried close to water schemes near Loughrea, Co Galway, and similar action has been threatened in Co Mayo.
"Unfortunately it is not a simple question," said Prof Vincent Dodd, Dean of Engineering and Architecture at UCD. He doubts that composting is an option for such volumes of material. But carcass numbers will build up quickly in the coming months and they will have to be dealt with. "Are we going to freeze them forever?" he asked.
An incineration plant for carcasses was therefore "tied up with the whole question of waste", and whether society would tolerate incineration. "I think it is pretty difficult to sustain the idea that each village should have a church, a pub and a dump."
Yet incineration is not going to help get the Government on top of the BSE waste mountain, according to Mr P.J. Rudden, director at M.C. O'Sullivan, consulting engineers. His company has been promoting the incineration option for municipal waste through regional plans.
If immediate action was taken to build an incinerator for this animal waste, it could not be commissioned before 2004, Mr Rudden said. It would require at least two years for a planning process that would attract powerful and determined local opposition at any site chosen. Constructing the plant would take a further 18 months. Incineration does not provide a quick answer for the impending carcass stockpile.
Doubts about the justification for a large-scale cull were raised by Mr Trevor Sargent TD, Green Party spokesman on agriculture and food. It was being pursued at Government and EU level as much to protect markets as to protect health. "It is being treated more as a marketing problem than as a scientific problem," he said.
Mr Sargent said anaerobic digestion of animals processed into meat-and-bone meal was the best route for disposal and would also produce a fuel source, methane. More comprehensive testing might also provide an alternative to destruction, with animals cleared for BSE being allowed back into the food chain. There are alternative technical approaches, Mr Rudden said, but ultimately all were based on a form of thermal treatment, the use of extreme heat to dispose of carcasses.
Gasification involves heating to 2,000 degrees, , degrees C which produces a crystallised substance that could be used as a concrete aggregate. Pyrolysis produces a usable fuel and a charcoal-like residue. "None of these systems are proven, they don't have a track record," Mr Rudden added. Incineration did and "is very much part of European policy", he insisted.
Mr Rudden was dismissive of any dioxin risk associated with carcass incineration. "There is more dioxin generated by the open burning of waste here than all of the incinerators that have been proposed. The [dioxin] link to incineration is purely historical." Nor was there any proposal that there would be dual use of an incinerator for animal and municipal waste.
"I am not concerned about the emissions," Prof Dodd said. "If run properly, they work." Once an incinerator was installed, however, "you have to feed it", he added, and this could blunt efforts to reduce the waste stream through re-use and recycling. Sustaining a high enough volume of material through the incinerator would then become the challenge and dual use could come into play.