BPM is the "Best Practicable Means" and this section is a non-technical explanation of a widely used defence against statutory nuisance actions, when the nuisance has been created on trade or business premises
This section will mainly be of interest to UK readers. It has little relevance to international considerations.
Not only can Best Practicable Means (BPM) be the basis of an appeal against a noise abatement notice, but The Environmental Protection Act 1990 (The Act) makes specific provision for it to be a defence against proceedings for contravention of a noise abatement notice or order (Sn.80(7) and Sn. 82(10)). Note that there is no mention of Best Practicable Means being a defence in actions under Section 81(5) and therefore it appears likely that this defence is not available.
If we now examine BPM more closely. It is sometimes characterised is being "The Polluters Charter" because under some circumstances it allows the noise or vibration pollution to continue; however "the devil is in the detail". The Act defines BPM as
Finally "in circumstances where a code of practice under section 71 of the Control of Pollution Act 1974 (noise minimisation) is applicable, regard shall also be had to guidance given in it." Unfortunately the Codes of Practice currently adopted are not particularly wide in their application (e.g. noise from Model Aircraft) except for BS.5228 which considers noise from construction and open sites.
The "current state of technical knowledge" has been interpreted to mean that the BPM can change and evolve; for example in the case of a factory it may be served with a Notice, and successfully appeal it on BPM; however if a new quieter, cheaper process is subsequently developed then the factory would no longer be taking BPM and the Notice could be re-served, or action for non-compliance recommenced. In some circumstances it may be considered that moving the business would be the best method of noise control, but Swarbick & Co quotes "Manley & An v New Forest DC" as "A house owner gained permission to run a dog kennel. It grew and eventually the authority served a notice claiming it to be a statutory nuisance because of the noise. The defendants appealed asserting they had used the 'best practicable means' to reduce the noise. It was not within the section to require such a business to move, although the expansion of a business was relevant."
The "local conditions and circumstances" generally mean that solutions which worked elsewhere may not be appropriate; for example the best way to reduce noise might involve the demolition of a listed building, or alternatively erecting earth mounds, for which the local authority will not grant consent; in both instances the "local conditions and circumstances" would mean that the best course of action could not be taken, and this is all envisaged within BPM.
Finally the "financial implications" mean that spending on noise control has to be reasonable within the resources of the business; for example it may be reasonable to expect a multinational company to spend £1m on reducing noise at one of their major plants, but on the other hand spending a similar amount on a corner shop would be unreasonable. There is case law that it not sufficient merely to show that there would be an adverse financial impact.
The Act further states that Best Practicable Means is to apply only so far as compatible with safety and safe working conditions; as an example in an industrial noise case, the local authority required the disabling of an automatic waste paper removal system, which had a noisy fan, and the use a manual (quiet) system instead; however, workers putting their hands into operational machinery was not safe, and therefore not in accord with BPM.