On the chemical water quality in Hoylandet, a reference area for acidification research

Chemical and physical water quality parameters have been analyzed in a synoptic study of 101 lakes and 103 rivers and streams in Hoylandet, a coastal catchment in Central Norway. The area is sparsely populated and most sites were unaffected by local pollution. Cambro-Silurian sedimentary rocks, porphyric granites and migmatitic gneisses are represented within the area and gave variable concentrations of dissolved salts in surface water. Conductivity varied from 0.6 to 20 mS m(-1) and pH from 5.0 to 7.6. Salt from sea spray dominated in dilute water in more elevated parts of the catchment while chemical weathering products were dominant in lower. The concentrations of all major ions and pH decreased with increasing elevation. Non marine sulfate occurred in moderate concentrations. pH values less than 5.5 were rare and the area as a whole did not seem to be subject to acidification.