There's a common perception that the UK will move to thermal treatment of sludges within the next decade - not necessarily as a result of evidence of harm, but in the absence of evidence of safety, particularly for the very many pollutants that partition to sludges during wastewater treatment. Preventing those pollutants from entering the system would provide the ultimate solution to this challenge and revert sludge back to its fundamentally useful ingredients of carbon and nutrients. But what would such a transformational change require? Spanning effluent consents, green chemistry, environmental health, ecosystem collapse and producer responsibility, this presentation will explore the range of current levers and blockers - and suggest that it's a case of when, rather than if we un-bake the sludge cake.