Periodisk avrenning av tungmetaller - en feltundersøkelse gjort ved Steinsjøen skytefelt

This report presents a study of Pb, Cu and Sb contamination of a small stream at Steinsjøen shooting range in Norway. The main purpose of the study was to investigate the dissolved heavy metal concentration during episodic events and during periods of high precipitation. Samples were collected during the spring and in the first part of the summer in 2001. Samples were also collected during an excavation event in and close to the stream in November the same year. During the snowmelt period the flow in the stream was significantly higher compared to the rest of the monitoring period. The amount of heavy metals transported during this period was very high. As much as 30% of the total heavy metal runoff occurred during this period. No correlation was found between the concentration of heavy metals and the flow. After the snow melting period several precipitation events occurred. In contrast to the snow melt episode the concentration of heavy metals correlated very well with the flow. Compared to the low flow periods, the concentration was as much as four times higher during the high flow periods. The study also indicated that excavation has an effect on the heavy metal concentration, however only in short periods.