Impact of Bottom-Sediment Removal on 137Cs Contamination in an Urban Pond

Many irrigation ponds in Fukushima Prefecture were decontaminated due to the contamination of radiocesium released from Daiichi Nuclear Power Plant. To evaluate impact decontamination on 137Cs dynamics an urban pond Koriyama City, Prefecture, Japan, temporal changes concentrations bottom sediments and water investigated before after bottom-sediment removal. Post-decontamination, inventories decreased by 46–89%. relatively high fine decontamination, also at points near inlet decontamination. Following mean concentration suspended solids (SS) dissolved 52% 5%, respectively. Even normalized SS water, which calculated dividing each area, higher than those rivers, dam reservoirs, elsewhere Fukushima. The positive correlations between δ15N values, indicator source contribution sediments, upper 5 cm implied that areas gradually increased pond. results underline importance secondary inputs highly urbanized catchments.