— The processes involved in the manufacture of pulp, board and paper require huge amounts of water, which is why it is crucial for mills to be situated in areas where the available water reserves are not in short supply, stresses Jukka Karppinen, Vice President of Metsä Group.
Metsä Group positions itself as a responsible forest industry company whose products improve people’s everyday lives and promote well-being in a sustainable way. The Group’s core operations encompass tissue and cooking papers, board, pulp and wood products, as well as wood supply and forestry services.
— The main consumers of water are our pulp, board and paper mills. We are fortunate in that none of our production plants are situated in an area where water is in short supply; on the contrary, the majority of our mills are in Finland and Sweden, which are both known to have abundant water reserves. As much as 98 per cent of the water we utilise is surface water extracted from rivers or lakes, Karppinen says.
Some of the Group’s mills in Central Europe also use groundwater.
— Water extraction, however, is tightly regulated in the plants’ environmental permits to ensure that the supply of groundwater reserves is also sufficient for the needs of others, Karppinen stresses.
From wastewater to clean water
The impacts of water utilisation by pulp, board and paper mills mostly concern wastewater. According to Karppinen, all of the water utilised in the mills’ production processes is effectively treated before being released back into the water system. Many mills have their own wastewater treatment facilities that make use of proven and efficient active sludge technology.
— Strict limits have been set for wastewater loads in the environmental permits of every mill. Measurement results related to the loads are also regularly reported to the environmental authorities and other stakeholder groups. All mills essentially have a certified management system in place for environmental matters, with targets set for development measures related to water utilisation, Karppinen explains.
Metsä Group continuously boosts the efficiency of its water utilisation such that process water is recycled within the mill. The water is typically recirculated six to ten times before it is returned via the wastewater treatment plant to the water system. Water recycling and re-use require internal treatment stages, which vary in number and quality from mill to mill.
Less water, less energy
— The impetus for enhancing the efficiency of water utilisation stems largely from energy savings and reducing the wastewater load – not so much from the scarcity of water reserves, Karppinen points out.
Water utilisation consumes energy because the water must be pumped from one place to another, heated for the production process and, finally, treated.
— If less water is required, less energy is required. In addition, a smaller amount of wastewater going to the treatment plant means a better treatment result and thus reduced environmental impacts caused by wastewater, Karppinen stresses.
No internationally approved method or standard for measuring the water footprint currently exists. Metsä Group, however, is currently engaged in a pilot project to assess the water footprint of board produced at the Simpele mill.
— The calculations are based on a life-cycle assessment and the draft of an ISO water footprint standard which is currently being prepared. The results are expected to be ready in June, says Karppinen.