摘要：The commercial vessel uses sea water to stabilty a vessel when the vessel is not loading a cargo. The water stabilized for the vessel is known as ballast water. The activity of loading the ballast water for the ship from origin port and dissposal to the distination port has caused impact on spreading the unidenfied organism the local port. Aim of the study to determine disposal value of water ballast either from a foreign merchant vessel or domestic merchant vessel so that Port of Tanjung Emas Semarang (PTES) is able to determine a policy on ballast administration from merchant vessel include a data of Arrival and Departure Report of the Vessels (ADRV) documents for the last five years (2009-2014). Disposal ballast water of domestic vessel to PTES is average about 37,036 m3and increased by 76.68% in a year. Yearly ballast water disposed from the foreign commercial vessels has reached 576.045 m3 for the last 5 years. The increasing of ballast water is about 122.19%. Level of vunerability on the PTES waters is due to ballast water dissposal caused mainly from foreign commercial vessels. The PTES administration should provide water reservoir and and water ballast treatment of commercial vessels which has 51,090 m3/per month or 81,744 kl/month.
