Metsä Board isn’t resting on its laurels but has set targets for reducing water use. The numbers are impressive: Since 2010, Metsä Board has reduced the use of process water by 16 per cent – this is 1 per cent from the target to be achieved by 2020. Water use is also monitored by the government by strict environmental permits set for each mill.
"Predicting the future, I’d say we are moving towards more closed water cycles. For example we have great plans for our Äänekoski mill. But at the same time I must highlight that even the older mills can be efficient: our oldest mill Tako is a great benchmark in Tampere city centre.”
Some of Metsä Board’s mills are integrates (the board and pulp mills are on the same site) where the efficiencies can be further enhanced. Soili Hietanen gives an example: “Husum mill is a big integrate where the pulp mill delivers wet pulp to the board mill, in other words, a part of the board mill’s water comes from the pulp mill. There’s no need for drying the pulp before using it.”
Drinking from the same lake
What happens to the water that cannot be reused? Mills have effluent treatment plants where water is carefully purified before returned to the nature.
“The percentages of recycled and reused water vary from mill to mill, mainly depending on process quality requirements and local water conditions.”
But the water from the effluent treatment plants is clean, Hietanen knows:
“Near the Äänekoski mill, the water is released back to the lake where we go swimming from the mills’ club house. And from the same upstream is where the Finnish capital area gets its drinking water. As you can guess, the water is very carefully analysed and monitored by authorities.”
But who knew that the sludge from the effluent treatment plants is utilised as energy? The boardmaking process is full of side streams, efficiencies and synergies which all count in the big picture being the best examples on circular economy.
Hietanen mentions one more aspect on how Metsä Board’s process is water efficient: because there is so much rainfall in Finland (annual precipitation is between 600 and 700 mm) forests need no watering. Forests are also very important in the hydrologic system, they act like a giant sponges filtering and recycling water.
“Every step of our process is carefully considered. From the above it’s easy to make the connection to the UN’s sustainable development goal no 6 which is about ensuring availability and sustainable management of water and sanitation. We are committed to the UN’s Global Goals.”