Anslow v Norton Aluminium [2012] EWHC 2610 is the latest nuisance group action to be decided by the High Court in which the Court held that the lead claimants had suffered odour nuisance. The damages awarded by the Court are likely to mean the defendant company paying out in excess of £1.4 million which is thought to be one of the largest awards ever made in private nuisance proceedings The company in question is now (as a result of the proceedings) in administration.

As with the litigation in Barr v Biffa [2012] EWCA Civ 312 it is striking and chilling that the costs incurred in fighting the case were astronomical compared with the modest value of each individual claim (£3 million in Barr v Biffa).

The profile of group actions in private nuisance claims is that each individual claim is modest, worth a couple of thousand per annum at most and often less. There can however be hundreds of individual claims which all raise the same issues. The challenge is to ensure that the claims are assessed economically, efficiently and proportionately. The assessment of quantum for loss of amenity is another complexity.

In Anslow the Court examined and decided the claims of a few selected Claimants. In doing so the Court scrutinised the written material relating to the contemporary operation and regulation of the factory operations. Whilst standards of environmental management and compliance with regulatory requirements are not directly relevant to whether the Claimants experienced unreasonable interference, they do go to the likelihood that the plant was the cause of the matters of which the claimants complained and to the likely extent, duration and severity of the interference which its activities were likely to have caused throughout the claim period.

The Courts have acknowledged that damages for loss of amenity value cannot be assessed mathematically. Awards tend to be ‘modest’. In practice, the Courts have adopted an amalgam of two approaches to assessing quantum which can involve ‘cross checking’ the outcome of one approach against the outcome of the other. One approach is based on rental value and on the difference between the rental value of the unencumbered property as compared with its rental value when afflicted with nuisance The other approach is to assess damages generally referring as appropriate to decided cases in so far as they are any help.

In Anslow the Court rejected the rental value approach as not practicable or reasonable because there was too little primary data. The Judge awarded annual sums ranging from £2000 to £750 depending on the degree to which individuals were affected by the odours which was assessed by reference to odour modelling. This seems a correct and proportionate approach on the basis that low value claims covered by a Group Litigation Order cannot expect the same attention to detail as they would in high value claims. Claimants must take the rough with the smooth across the whole Register.