BREFs are the product of a lengthy exchange between industry and regulators on the best available techniques (BAT) which operators should use under the integrated pollution prevention and control (IPPC) regime.
Foundries in the UK came under IPPC some time ago. Some 120 operators applied to the Environment Agency for an IPPC permit in 2001, and 60 smaller sites made applications to local authorities last year.
A two-year delay in the publication of the foundry BREF by the European IPPC Bureau meant that a final version was not available to inform the Agency's interim guidance for the non-ferrous and ferrous metals sectors (ENDS Reports 317, pp 30-31 and 318, p 43 ). The Agency's guidance will need to be revised in the light of the BREF, although many of the requirements appear to be comparable with those already in the existing guidance.
The IPPC Bureau says that for the most part, work on the foundry BREF was marked by a high degree of consensus between the various stakeholders. The BREF lacks performance data from the non-ferrous sector, which was under-represented on the Bureau's working group, because many firms in the sector are SMEs with limited resources.
The key environmental issues for the sector are emissions to air, including particulate matter and metals, dioxins, volatile organic compounds (VOCs) and odour.
The sector uses several different furnace designs, chosen on technical grounds such as the type of metal to be melted. The BREF does not specify which furnace type is preferable, even though emissions levels of SO2, NOx vary quite widely between them. On the key issue of dust emissions, the BREF says that emissions levels of less than 20mg/m3 are achievable with the use of bag filters or wet scrubbers - less ambitious than the 10mg/m3 currently required of UK operators.
On emissions from casting houses, the BREF says that companies should minimise fugitive VOCs from chemically-bonded sand which can lead to odour problems. Companies should consider alternative moulding methods, such as inorganic binders which emit no VOCs. The BREF describes this as an emerging technique that has been successfully used in the aluminium castings industry.
Companies should also reuse a high percentage of sand, up to 90-100% for some types, within the moulding process. This is standard practice at UK foundries where the landfill tax has provided a strong incentive to reduce waste.
However, the requirements on dioxins proved more controversial. The BREF says that levels of 0.1ng/m3 are achievable at all types of foundry, using in-process controls and abatement such as activated carbon injection or catalytic bag filters. In contrast, the Agency's guidance specifies an indicative BAT level for ferrous foundries of 1ng/m3.
The BREF says that ferrous foundry operators have expressed doubts about whether dioxin abatement is applicable at ferrous foundries, despite wide experience in other sectors including steel making, non-ferrous and waste incineration. Nevertheless, operators are now likely to have to consider the fitting abatement in order to achieve the indicative BAT.
At non-ferrous foundries, the Agency's 2001 interim guidance levels has already reduced levels of dioxins using abatement from 1 to 0.1ng/m3 - although a higher level of 0.5ng/m3 is acceptable where it can be achieved through in-process controls alone.