Companies urged to comply
Maria Cull, from law firm Herbert Smith, analyses recent court rulings relating to industry and the environment
The four-year guaranteed period will end between June and December this year - during that time the Agency could not revoke the consent or modify its conditions without the agreement of the consent holder.
Now the Agency wants to take control to ensure that the River Dee and its tributaries are not being polluted. All companies have been told that the Agency will be reviewing the consents.
The WPZ was set up as a legal mechanism to give the Agency additional powers to regulate commercial, industrial and agricultural premises in sensitive catchment areas.
While companies, including Dwr Cymru Welsh Water, Dee Valley Water and United Utilities, provide water from the Dee to some 2.5m people and industries in North-East Wales and North-West England, the Agency also has a responsibility to ensure that there is enough fresh water for fisheries and natural habitats.
Mark Chapman, the Agency's environment manager for the Freshwater Dee catchment, said: "I believe that there are a number of companies within the zone that do not have a consent but by law are required to do so. I would urge any such company to contact the Agency."