Market liberalisation in the water industry will not work through common carriage, according to Tony Ballance, former chief economist at regulator Ofwat. Water quality and the security of supply would be jeopardised with no single body responsible for overseeing the network, he said. The set-up and running costs of a market with multiple buyers and sellers, similar to that for the energy industry, would be too great to make it viable, added Ballance, now a director of consultancy Stone and Webster.