Polychlorinated Biphenyls (River Usk) Mr. Flynn To ask the Secretary of State for Wales what arrangements have been made to deal with contamination of the River Usk by polychlorinated biphenyls carried in vessels in the river. Mr. Grist We are not aware of any such incidents. However, were such an event to occur it would be a matter for the National Rivers Authority, the local authority and if it were within a port, the harbour authority.