Invercote - Water environment at the Iggesunds Bruk mill
Iggesund Mill is located on the narrow inlets of Iggesundsfjärden and Gårdsfjärden, which have low water turnover.
The company takes part in the programme for coordinated monitoring of receiving bodies of water in the north-eastern part of county Hälsingland which refers to monitoring of the environmental effects of different activities in different catchment areas and in the coastal waters.
For annual data on reported emmisions to water from the Iggesunds Bruk mill please see Invercote Environmental Declaration
Strong improvement of marine environment during the last 30 years
The mill's emissions of eutrophicating substances have fallen sharply since the 1980s. In trial fishing in 1987, the fish life in Gårdsfjärden was characterised as typical of areas of water high in nutrients. Some changes in the direction of more normal status were noted in 1996, but fish production remained high and with a preponderance of the carp family.
Recovery proceeds slowly in such enclosed areas as Gårdsfjärden, where large amounts of organic material and mineral nutrients from earlier emissions have accumulated on the bottoms.
In 1996 impairment of liver function and reproduction was observed in perch in Gårdsfjärden. However, growth and survival were normal. Further studies of perch in the waters off Iggesund were performed, with similar results to those found in the study in 1996.
Reproductive studies were performed on both perch and zebra fish in 2001 and 2002. The results show that perch that have spawned in the receiving body of water produce eggs with just as good hatchability and larval survival as the perch in an unaffected reference area, and the studies in the laboratory on zebra fish did not indicate any effects.
In late 2009 a treatment plant was brought on line with chemical flotation after the existing aerated lagoon. This has resulted in a reduced load on the receiving bodies of water, particularly regarding mineral salts.
In connection with an application for a new environmental permit, the company conducted a follow-up fish study in autumn 2009, which showed that a small number of significant differences, which cannot be regarded as biologically significant, existed between the sites studied. No evidence was discovered of the inhibition of reproduction found in previous studies, and the results therefore indicate clear recovery. The fish study was conducted before the chemical flotation plant was commissioned, which means that the recovery that has occurred must have had another cause, such as internal measures already taken.
As part of the permit application procedure, a hard-bottom inventory was also conducted in August 2010, and the study showed that there has been a large-scale improvement in the inner reaches of Gårdsfjärden and the outer reaches of Enångersfjärden since 1987. It is impossible today to differentiate the effect of outflow from the Iggesundsån river in the studied reaches of Gårdsfjärden on the plant communities on the bottoms from the effect of the point source Iggesund Mill in the same receiving body of water. There is no visible toxic effect.
The sediments in Gårdsfjärden are finely divided, oxidised and teeming with life. Filtering organisms such as freshwater fungi, barnacles and hydras occur on rocks. Nor do TOC concentrations in water and sediment suggest any unusual conditions.