Composting is well established across the UK, with 1.97 million tonnes having been composted in 2003-4, primarily in the form of open windrow green waste. By 2016, this figure needs to rise to 10 million tonnes if landfill diversion targets are to be met.

Given that a typical licensed site runs at 25,000 tonnes a year, this would mean a further 320 sites need to be built in the next 10 years. And, even if some managed 50,000 tonnes a year, it means a lot of development – and getting it right becomes even more important.

There is likely to be a rapid increase in in-vessel facilities that can compost food wastes. Generally, composting sites are well run and do not create many problems. But some local authorities have had major issues with composting facilities – usually involving odour and traffic. To minimise the risk of nuisance, there are some basic points that should be considered in letting and awarding contracts.

The purpose of composting should be to produce a good product, fit for purpose, that has a sustainable market – whether to agriculture, amenity or bagged products for the retail market. Compost should be produced to at least PAS100 standards, and the location of the facility is crucial to avoid causing a nuisance to neighbours.

Consideration should be given to the type of facility, whether it should be green waste only or to include food waste, and should it be a single large-scale operation or a number of smaller facilities.

Many of the problems commonly associated with composting operations have been with exempt sites. The current rules allow for 1,000m3 of active composting at any one time; this, in theory, suggests annual inputs of up to 5,000 tonnes a year.

An exempt site by its very nature has minimal regulation, and so does not have to meet the same standards as a fully licensed site – and is somewhat open to abuse. Environment Agency rules are changing and it is likely that an exempt site will be restricted to a maximum of 400 tonnes a year.

Odour seems to be the main bone of contention with composting sites, whether licensed or exempt. Therefore, unless it is going to be a fully enclosed facility where all odours are controlled, site location is crucial. For an open-windrow facility, the site boundaries should be 250m from any receptors – which substantially reduces the number of potentially available sites, especially in the crowded Southeast.

Victims of geography

The main problems associated with compost sites tend to be that they are in the wrong location or are not being run well. Cost is often at the root of problems, especially on exempt sites – which some LAs have used as a cheap composting route. It is extremely difficult to run a composting site properly with gate fees of less than £20 per tonne. Well-run sites have average gate fees in the region of £25 per tonne.

To help minimise these problems, LAs need to specify carefully what they expect from a compost-provider. It is important that a potential contractor has the necessary skills to run a site properly, and understands the basic waste management rules.

It can be extremely beneficial for an LA to engage a specialist consultant to assist with the procurement process. Companies such as Enviros, the Organic Resource Agency and ADAS have specialist teams with a wealth of experience in ensuring that tenders are drawn up in such a way that only professional compost operators with sufficient experience are likely to be able to compete.

Prior knowledge

Getting planning for compost facilities is often difficult and, before awarding any contracts, the local authority needs to know either that planning has been obtained or that it is likely to be granted. In some cases, it may be possible for a LA to identify a suitable site and to get planning permission before then inviting tenders to build and operate the facility in question.

At the very least, the LA at a strategic level has to ensure that the waste team and planners will work together to encourage composting development while at the same time working within national planning rules.

It is essential for the future of composting that all compost operators work to best-practice standards and that LAs do their part by ensuring they let out contracts that achieve best value in terms of proper composting, and not necessarily for the lowest price. And contracts must be monitored on a regular basis to ensure they continue to meet the tender standards.

The majority of compost sites work very well and do not cause a nuisance to their neighbours. The few sites that do create problems must not be allowed to give the industry a bad name.

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