In 1994, HM Inspectorate of Pollution launched the "Bedford protocol" which set requirements for the growing number of cement works seeking to carry out trial burns of substitute fuels (ENDS Report 236, p 30 ). Last year, the House of Commons Environment Committee criticised oversight of the trials by HMIP and the Agency, and questioned the validity of emission tests under the protocol (ENDS Report 266, pp 30-32 ).
The Agency is now consulting on a revised version of the protocol. This sets requirements for the content and advertising of applications, public consultation, kiln operation, conduct of trials and monitoring - including minimum test frequencies for each pollutant and a soil sampling protocol.
The Agency is requiring greater public consultation, in line with its plans for dealing with "contentious" applications (ENDS Report 275, pp 36-37 ). New requirements include the holding of at least one public meeting to discuss the proposals.
Data from a six-week trial are likely to be the minimum required for a satisfactory assessment, the Agency says. It will carry out its own, smaller programme of check monitoring during each trial, and may require further tests if it finds poor agreement with the operator's results.
The Agency says that where cost savings result from the use of waste fuels "there may be some scope to tighten the improvement programme in the authorisation without imposing excessive cost." But it says that commercial details of fuel supply contracts will "probably" be classed as confidential.
In February, the Agency authorised Rugby Cement to increase the maximum substitution rate of SLF at its Barrington works in Cambridgeshire from 25 to 40%.
The Agency has also announced that it is minded to approve Blue Circle's application to carry out a second trial burn of scrap tyres at its Westbury works in Wiltshire. Last year, the firm dropped its application to burn tyres on a permanent basis after doubts were raised about the validity of its trial monitoring data (ENDS Report 268, pp 7-8 ).
Finally, the Agency has varied the authorisation for Castle Cement's controversial Ribblesdale works in Lancashire to set conditions on the operation of a new wet scrubber on one of the site's kilns (ENDS Report 256, pp 6-7 ). New emission limits for sulphur dioxide and particulates will not come into force until June to allow time for the scrubber to be commissioned.