LAWR

ENVIRONMENTAL NUISANCE Tackling AD odour concerns Any new development can cause concern, particularly if the proposal is something unfamiliar or comes with even the tiniest degree of potential risk. Anaerobic digestion (AD) plants often tick these boxes. One of the perceived issues that can create a cause for concern is odour. Stephen Locke explains his thoughts on odour management and how good communication can help. naerobic digestion can be an ideal way of treating organic wastes and producing a useful by-product – digestate. However odours from a number of sources on sites, as well as atmospheric emissions from the biogas engines and infrastructure, have the potential to cause impacts at sensi- tive receptors. The risk of odour generation from AD and other bio-fuel plants is affected by a number of factors. These include : • The feedstock delivery process • The types of feedstock • How the feedstock is handled • The type of gas management system • The digestate storage and spreading protocols The type of feedstock is crucial in terms of odour potential with agri- cultural AD plants generally having a lower odour potential when compared to plants handling products such as food wastes. The perceived nuisance issues asso- ciated with AD have been exacerbated by a small number of cases and the fear of local resident's quality of life being harmed. Whilst there is often agree- ment about what constitutes pleas- ant and unpleasant odours, there is a wide variation between individuals as to what is deemed unacceptable and what affects our quality of life. As with any project careful pre-sub- mission planning is required to assess the issues. Site selection is crucial and many local planning authorities will want to see some sort of rationale as to why a particular site has been chosen. It may be that the plant needs to be located on a certain site because of proximity to grid connection or because the heat produced is going to be used locally for another use. Communicating your ideas to the local authority and to the wider com- munity will help people understand why the plant is required in a par- ticular location and how you intend to mitigate risks. Careful planning In my view, AD facilities need to be designed and operated with odour pre- vention in mind. The two main areas where odour can be released in the AD process are in the reception area where waste is delivered and from ammonia in the digestate. Other ways of odour " Deliveries of waste products should be dealt with as quickly as possible. " 32 Local Authority Waste & Recycling September 2014 A Real or illusory? ►

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