Mr. Matthew Macken:

That is very heavily regulated from what I see in my work in the AD sector. There is also the matter of health and safety in terms of digestate. A nutrient management plan is always created for wherever it may go. Application rates are then applied. It has to go to the relevant county council which has to approve it. Only then can it be moved and spread on and such. It is usually directly injected into the ground to avoid emissions that way, and through the process, it is stabilised using alkaline, it is pasteurised, heated, reheated, retested and rigorously retested again. From what I have seen going back to 2009 or 2010 with the plant that I am involved in, there is yet to be an issue in any nutrient management plan, NMP, that has been sent out with any heavy metal traces or anything like that surrounding the application of biosolids, sludge or digestate.