A review of non-OP dips was promised by the VPC a year ago in a report on the safety of OP dips (ENDS Report 265, p 31 ). The move was a response to growing concern about water pollution incidents caused by dips based on synthetic pyrethroids, which are highly toxic to aquatic invertebrates.
In 1995 and 1996, invertebrate life in about 100 kilometres of rivers and streams was severely damaged by incidents known or strongly suspected of being caused by illegal or careless disposal of pyrethroid dips (ENDS Report 263, pp 4-5 ). More incidents occurred last year, including one which affected eight kilometres of a Welsh river.
In its latest review, the VPC acknowledges that the use and disposal of non-OP dips is causing a "serious environmental problem." There are "regular reports" of pollution incidents, even though under-reporting is likely because of the remote location of dipping and the difficulty of identifying them except by biological monitoring. Such incidents, it says, are "of great concern because they occurred over long stretches of the most ecologically valuable rivers and recovery was slow."
The review also notes that water quality standards for pyrethroids are being breached as a result of discharges from wool washing processes. A working group with representatives from the textile, water and sheep industries has been set up by the Environment Agency and the Veterinary Medicines Directorate to consider solutions.
The VPC's main recommendations are for changes to the certificate of competence scheme for sheep farmers. At present, farmers may not buy OP dips unless they have a certificate. The Scottish Environment Protection Agency has been pressing for two years for this requirement to be extended to non-OP dips, and the VPC has now accepted this. Agriculture Minister Jeff Rooker announced in a parliamentary answer that consultation on the necessary legal changes is under way.1The Government has also accepted a recommendation that users should receive practical training in the use and disposal of dips as part of the certification scheme. And the examination used in the scheme will be amended to ensure that nobody can pass without displaying a certain level of knowledge on the environmental aspects of sheep dipping.
However, these changes will leave many farmers untouched because they already have certificates. According to the VPC, 12,800 of the expected 20,000 certificates for OPs have been awarded. The Government has accepted its recommendation that certificate-holders should be "encouraged" to take the new wider test, but there must be some doubt whether many will do so.
The new groundwater regulations proposed by the Government in January are likely to make more of an impact because they would oblige farmers to notify the environment agencies of plans to dispose of spent sheep dip and consult them about suitable dipping practices. Disposal of sheep dip to soakaways is likely to be banned (ENDS Report 276, pp 42-43 ).
The Government has accepted the VPC's advice that the date package for authorisation of pyrethroid dips should include toxicity tests on aquatic invertebrates, and in "flow-through" rather than static tests. It has also promised to press dip suppliers to provide sales data to allow proper environmental risk assessments.