A large number of tin (Sn) mining activities carried out in the coastal area of Bangka Belitung has a direct impact on water quality, especially water turbidity. Turbid waters can produce large amounts of phosphate in local waters, and its distribution is influenced by the direction and speed of ocean currents. This study aims to determine the value of water turbidity concerning the amount of phosphate content in two different locations with tin (Sn) mining activities as a source of pollution. This research was conducted in July 2018, in the coastal waters of Tanah Merah Island and Semujur Island. The results of the water turbidity value in the Tanah Merah coastal waters were 12.50-22.50 NTU greater than that of Semujur Island waters, namely 4.14-7.22 NTU. The phosphate value in Tanah Merah coastal waters is 0.02-0.05 mg / L, greater than the Semujur Island waters, which is 0.01-0.02 mg / L. This indicates that Tanah Merah coastal waters are more turbid with a value higher phosphate. The existence of tin (Sn) mining activities in Tanah Merah waters has an impact on the amount of water turbidity that can bind phosphate elements compared to Semujur waters.