This report describes ballast water data reported by crude oil tankers arriving to Valdez and Prince William Sound, Alaska, from 2005 through 2015.
The analysis includes the following: Annual number of vessels that discharged ballast water, Annual volumes of ballast water discharge, Annual volumes of dirty ballast water discharge, Ballast water source locations (2010 ? 2015), Ballast water management locations, Ballast water management rates, Ballast water management methods.
Between 2005 and 2015, 23 crude oil tankers reported discharging 87,855,788 metric tons of ballast water to Valdez and Prince William Sound. The majority of ballast water was sourced from locations on the west coast of the United States such as Puget Sound, WA, and San Francisco Bay, CA, resulting in 96% coastwise ballast water discharge. The remainder (4%) was sourced from distant locations such as Hawaii and Singapore. Of the 34% of ballast water that was reported to be managed, flow-through ballast water exchange was the preferred method (67%), followed by empty-refill exchange (29%), and alternate methods (4%).
Trends in data should be considered in the context of changes in policy during the time period. For example, the Environmental Protection Agency’s 2008 Vessel General Permit (VGP) significantly influenced the management and recordkeeping requirements for crude oil tankers engaged in coastwise trade. The 2008 VGP went into effect in Alaska on February 6, 2009.