Division BAT 46 In order to prevent or reduce emissions to soil and groundwater, BAT is to use all of the techniques given below.
United Kingdom
| Technique | Description | |
|---|---|---|
| (a) | Plant and equipment containment or bund | The parts of the plant in which treatment chemicals are stored or handled, i.e. treatment chemicals storage area, treatment, post-treatment conditioning and interim storage areas (comprising treatment vessel, working vessel, unloading/pull-out facilities, dripping/drying area, cooling zone), pipes and ductwork for treatment chemicals, and creosote (re)conditioning facilities, are contained or bunded. Containments and bunds have impermeable surfaces, are resistant to treatment chemicals and have sufficient capacity to capture and hold the volumes handled or stored in the plant/equipment. Drip trays (made of treatment-chemical-resistant material) may also be used as local containments for the collection and recovery of drips and spills of treatment chemicals from critical equipment or processes (i.e. valves, inlets/outlets of storage tanks, treatment vessels, working tanks, unloading/pull-out zones, handling of freshly treated wood, cooling/drying zone). The liquids in the containments/bunds and drip trays are collected to recover the treatment chemicals for their reuse in the treatment chemicals system. Sludge generated in the collection system is disposed of as hazardous waste. |
| (b) | Impermeable floors | Floors of areas which are not contained or bunded, and where drips, spills, accidental releases or leaching of treatment chemicals may occur are impermeable to the substances concerned (e.g. storage of treated wood on impermeable floors in the event that it is required in the BPR authorisation for the wood preservative used for the treatment). The liquids on the floors are collected to recover the treatment chemicals for their reuse in the treatment chemicals system. Sludge generated in the collection system is disposed of as hazardous waste. |
| (c) | Warning systems for equipment identified as ‘critical’ | ‘Critical’ equipment (see BAT 30) is equipped with warning systems to indicate malfunctions. |
| (d) | Prevention and detection of leaks from underground storage and ductwork for harmful/hazardous substances and record-keeping | The use of underground components is minimised. When underground components are used for the storage of harmful/hazardous substances, secondary containment (e.g. double-walled containment) is put in place. Underground components are equipped with leak detection devices. Risk-based and regular monitoring of underground storage and ductwork is carried out to identify potential leakages; when necessary, leaking equipment is repaired. A record is kept of incidents that may cause soil and/or groundwater pollution. |
| (e) | Regular inspection and maintenance of plant and equipment | The plant and the equipment are regularly inspected and serviced to ensure proper functioning; this includes in particular checking the integrity and/or leak-free status of valves, pumps, pipes, tanks, pressure vessels, drip trays, and containments/bunds and the proper functioning of warning systems. |
| (f) | Techniques to prevent cross-contamination | Cross-contamination (i.e. the contamination of plant areas that usually do not come into contact with treatment chemicals) is prevented by using appropriate techniques such as:
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