Abstract
This paper describes the lasting effect of nutrient release reduction from bottom sediments with sand capping at Yokohama Port. The water quality in Tokyo Bay is still contaminated because of a large amount of nutrient release from contaminated sediments. In order to reduce the nutrient release from the sediments, Yokohama Municipal Government conducted a sand capping const.ruction at Yokohama Port. In the study, we carried out the undist.urbed bottom sediment sampling at Yokohama Port, and carried out the laboratory test.s for nutrient release rate from the sediments. From the st.udy, it is found that the nutrient release rate from the sediments without sand capping is larger than the sediments with sand capping. Therefore it is considered that the effect of sand capping on nutrient release reduction still maintains for 5 to 10 years after the construction.
