The chemistry of Norwegian groundwaters : II. The chemistry of 72 groundwat- ers from Quaternary sedimentary aquifers

Seventy-two samples of groundwater derived from Norwegian Quaternary (largely glaciofluvial or glacial) aquifers were analysed for a wide range of major and minor hydrochemical parameters. The waters exhibit a relatively uncomplex evolution from Na-Cl dominated, immature waters (which reflect marine salts in precipitation) to Ca-HCO3 dominated waters via calcite dissolution. The median pH of these waters is 7.37, in contrast to similar waters from crystalline bedrock aquifers with a median pH of 8.07. The water samples provide little evidence of significa- nt acidification or sulphatisation of groundwaters by 'acid rain'. In fact, a positive correlation emerges between non-marine sulphate and alkalinity/pH, suggesting dominantly lithological sources for non-marin- e sulphate. No groundwaters from Quaternary deposits exceed maximum recommended concentrations for Rn, F- and Na, while 10% fall outside the required pH range. This again contrasts with bedrock aquifers where 30% of waters are non-compliant with respect to one or more of these parameters.