Sammendrag
NIVA has monitored effects of emissions from Vajda-Papir Scandinavia AS to Drammenselva. The
focus was on possible impacts of emission of soluble organic components on aquatic life. The
monitoring program was based on samples from one station upstream of the emission point, and
another station 300 meters downstream. Physico-chemical parameters were analyzed from water
samples six times at each station. Macroinvertebrates were sampled in May and October. The data
were applied to classify ecological status in accordance to the Water Framework Directive.
The physico-chemical parameters did not show any difference between the upstream and
downstream stations. The macroinvertebrate samples were used to calculate the ASPT index, which
shows macroinvertebrate sensitivity to organic pollution, and was applied to classify ecological
status. Ecological status on the upstream station was good, while the downstream station was in
moderate ecological status.
Possible uncertainties associated with the results are discussed. Uncertainties especially associate to
possible influence of salinity from the fjord, possible occasional drift of sensitive macroinvertebrates
from upstream sites, and structural features of the ASPT index.
The results from 2018 are not consistent with data collected in 2015, where moderate status was
recorded at both stations. We accordingly recommend further monitoring, following the same
procedures as in 2018, in order to substantiate the findings from 2018.
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