UPM has studied extensively the ecological state of all of its pulp and paper mills effluent discharge areas, and has a number of bioindicators in use to measure the state of the environment.
Bioindicators measure the ecological state of waterways
Biological effluent treatment plants are effective
UPM treats all waste water in modern treatment plants before releasing it into watercourses. This is done at all UPM pulp and paper mills. Most of the mills have their own effluent treatment plants, but some mills rely on the municipal effluent treatment plants.
One example of natural bioindicators in Finland is the sea trout and whitefish. They appreciate all of the efforts made for the waste water treatment as the species are returning and now have their spawning places in the river Raumanjoki and Pitkäjärvenoja creek, which actually runs into the sea through the UPM Rauma mill site.
This development is encouraging as the species are classified as being very endangered in the Baltic Sea region. Reproduction may be tiny but it is important in order to guard the genetic heritage of the species.
What are bioindicators?
According to the EU Water Framework Directive, the ecological and chemical status of surface waters is assessed according to biological quality, hydromorphological quality and physical-chemical quality.
The amount of ecological data is often overwhelming and this is why environmental indicators, also known as Bioindicators, are often used. They are primarily used either to assess the state of the environment, or to diagnose the cause of the environmental change.
Typical bioindicator species are aquatic macroinvertebrates, fish, birds and vascular plants.
Our findings
The effluents enter the waterways from multiple sources, which is why it is difficult to evaluate the impact of just one mill.
As the aim is to draw clear conclusions about the impacts of effluent discharge on the waterways, monitoring should be designed in a way that supports this goal.
A good example is the Kymi River in Finland, where sampling sites are located above and immediately below the mill. The Water and Environment Association of the River Kymi has been monitoring the state of river for over 50 years based on the indicator species such as fish, benthic invertebrates and diatoms.
The abundance of Chironomidae (benthic invertebrate) in the Kymi River indicates that the conditions in the sediments have improved.
In 2018, the benthic survey of the River Kymi rapids was carried out for the first time in joint monitoring, where samples were taken from upstream rapids of the mill and from four rapids downstream of the load. In all the rapids in the main river, the benthic fauna corresponded very well to the benthic community of a natural rapids area according to the ecological state variables. Species classified as threatened were also present.
The condition and biodiversity of the river have improved considerably compared to past decades as wastewater treatment has become more efficient.
The latest results, published in 2022, indicate that the environmental impact of the UPM Kymi mills’ water load on the midge communities is low and that the benthic communities indicate a slightly oligotrofic river condition, i.e. having a low level of nutrients.
All of UPM's pulp and paper mills publish environmental statements, the EMAS reports. Traditionally, many mills also report on the status of watercourses around the mills. The biological treatment state has been found to be an effective way to remove dissolved organic contaminants and nutrients.
Figure: Map showing the Kymi River and the monitoring sites (Hilmberg, J., Raunio, J., 2021: Downstream of Kymi River water quality. Published in Kymi River Water and Environment Association no. 309. p. 32.)
