Environmental innovation is a much discussed, highly prized yet often elusive objective of governance programmes. Despite this, there have been relatively few studies of the everyday realities of achieving innovation on the ground. Addressing this gap, the paper takes a specific example of how the EU's Urban Wastewater Directive sparks a pursuit of new environmental standards in wastewater practices in the north of England. We argue that to encourage innovation, we must first appreciate its contingent and complex character. We do this by adopting an approach to innovation influenced by actor-network theory and conceive of it as being a highly contingent process of 'translation' through which actors' interests and identities, their practices, even the Directive itself are re-represented and re-ordered through the construction of new actor-networks. From such a perspective, governance of the water sector is shown to be a highly contested, unpredictable business shaped by situationally specific negotiations and compromises. Crucially, our case study reveals the importance of organizations performing 'intermediary' roles: facilitating the production of knowledge and re-ordering of relations between actors. Working at the interfaces between a range of actors and the Directive, intermediaries become integral to the ways in which objects and practices are translated and innovation realized.