An improvement project carried out at Obbola paper mill last year, resulted in a dramatic reduction of emissions to the Ume River. Emission levels are still at a very low level after just over a year.

The biological treatment plant at Obbola paper mill cleans the mills’ waste water before it’s released to the river. The purification is made in several stages where, among other things, suspended material (particles such as fibre residues, oxygen-consuming substances and biological sludge) is purified.

Last year, an improvement project was initiated with the aim of improving the purification in the biological treatment plant. The factory had experienced interruptions in the plant and risked not being able to meet the emission conditions for the next years, if no measures were taken.

A cross-functional team worked intensively for 12 weeks to collect data to be able to investigate the root cause of the disruptions at the plant. A number of measures were taken.

 -We established routines for how the sewage treatment plant should be run in the best way, explains Hans Thorén, Laboratory manager and team leader for the improvement team. We changed some equipment and then trained the operators.

After the end of the project in April 2018, emissions decreased significantly and have remained at a low level since then. - The past year has been magical, says Erik Sandberg, Process specialist. All conditional emission parameters have decreased significantly, some down to 25% of previous emissions.

- Here we can clearly see how relatively small changes can lead to large results, says Erik. We can be proud of how good a process can be if we to this together, he says.