Microbial diversity in trace metals contaminated groundwater and adjacent river

To understand long-term impacts of steel slag material on aquifer geochemistry and microbial communities, we conducted 4 sampling campaigns in the Gier alluvial groundwater (Loire, France) and the Gier river. In its northern part, the aquifer flows under a 200 000 m3 steel slag exhibiting high levels of chromium and molybdenum. After geochemical analysis, water samples were divided into two groups characterized (1) by high trace metals content or (2) high nitrogen content. Those samples were compared to non-contaminated samples, with geochemical characteristics similar to the river samples. To follow changes in microbial community, the V3-V4 region of 16s rRNA gene was sequenced.