I imagine the Position Statement has been pulled due to the Permitting Regs 2009 coming in and making them out of date.
We recently used pfa grout to shore up some mine workings. We needed to produce a risk assessment to show trhe pfa would not pose a risk to controlled waters and the operation was covered by an exemption from WMLicensing Regs. We needed to do this because we were proposing to bring pfa on to site from the power station and mix it with water on site. The mixing was deemed to be a waste treatment operation to make the pfa suitable for use as a grout. If we have brought in lorry loads of pre-mixed grout for direct use this would not have required an exemption as the Env Ag would have deemed the waste pfa fully recovered at the batching plant (which would have required a permit to cover the mixing). Now, with the advent of the Permitting Regs 2009 I'm not sure what exemptions would apply (they don't seem to apply to anything much these days) so I would look to use a WRAP protocol if possible or perhaps the Waste Code of Practice.
WRAP and Env Ag have produced this "Pulverised fuel ash and furnace bottom ash. A technical report on the manufacture of products from pulverised fuel ash (PFA) and furnace bottom ash (FBA)" which seeks to determine when the material can be considered to have ceased to be a waste; and have produced a draft quality protocol.
The UK Quality Ash Association have also produced tech sheets on using pfa as a grout. The electricity producers are rather keen to help too given that they have lots they want shot of.
Google "pfa and Northwich" to find out about the use of 1Mt of the stuff to stop Northwich from falling in on itself.
I believe the situation in Scotland is that SEPA still operate under the WMLicensing Regs and the "old" exemptions.
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