The anticipated rise in U.S. maritime traffic could increase the incidence of ships discharging wastewater and air pollutants at sea and in ports and increase the number of shipping accidents that result in spills of bunker fuel and oil. In the last few years, the impact of such occurrences on the environment and concern about their future frequency have brought the maritime industry under increased scrutiny.
To reduce the potential for oil spills, members of the International Maritime Organization (IMO) agreed in April 2001 to a 2015 deadline on the worldwide phaseout of most single-hulled oil tankers in favor of the added protection provided by double-hulled vessels.1 Other international actions underway include a ban on the use of ship hull paints that contain toxic tributyltin (TBT)2 and establishment of guidelines for dismantling obsolete ships.3 In addition, the IMO is working within the United Nations Framework Convention on Climate Change to reduce ship greenhouse gas (GHG) emissions, which contribute to global warming.
In the United States, pressure on shipping is coming from several directions. Ports are being assessed by state and regional officials, who are having difficulty meeting their commitments under the Clean Air Act. The Port of Los Angeles has, for instance, developed a program for the reduction of diesel particulate and smog-forming emissions, and the Port of Houston has conducted a comprehensive study of vessel air emissions. In July 2000, an environmental group published a report, A Stacked Deck: Air Pollution from Large Ships, reporting data on emissions of nitrogen oxide, sulfur, and GHGs from Category 3 ships.4 The report contained data estimated by the Sea Emissions Assessment project at Carnegie Melon University. This ongoing project has produced a globally mapped inventory of emissions from commercial ship engines operating internationally and estimates these emissions at more than 14 percent of all nitrogen emissions from global fuel combustion and more than 16 percent of sulfur emissions from world petroleum use. The project has estimated that 747 thousand metric tons of nitrogen oxides (NOx) are annually emitted from foreign and domestic ships in U.S. waters.5 The EPA National Emissions Trends database, which takes a different approach in estimating emissions, attributed 1,008 thousand short tons (916 thousand metric tons) of NOx to commercial marine vessels in 1998. Bluewater Network sued EPA for not regulating ship emissions, and in January 2001 the agency agreed in a settlement to establish air emission standards for Category 3 ships.
Public attention on the environmental impacts of shipping has been especially focused on the cruise industry. The Bluewater Network initiated a Cruise Ship Campaign in early 2000 with a petition to the EPA detailing various water discharges (see table 1). The petition suggested that not only was enforcement of existing laws weak but that these laws did not adequately address the problems. In response to the 2000 petition, EPA established a multiyear Cruise Ship Discharges Assessment study.
Previously, the U.S. General Accounting Office (GAO) had conducted a limited study on cruise ship marine pollution.6 The report found that between 1993 and 1998, foreign-flag cruise ships were involved in 87 confirmed illegal discharge cases in U.S. waters. A few of the cases included multiple illegal discharge incidents occurring over the 6-year period. Eighty-three percent of the cases involved discharges of oil or oil-based products, the volume of which ranged from a few drops to hundreds of gallons. The balance of the cases were discharges of plastic or garbage. GAO judged that 72 percent of the illegal discharges were accidental. The 87 cruise ship cases represented 4 percent of the 2,400 foreign-flag commercial ship illegal discharge cases confirmed during the 6 years studied.
Concerned about the growth of cruise ship activity in their coastal waters, but recognizing the lack of comprehensive data on ship discharges, California and Alaska set up task forces to collect data on ship effluents and air emissions. California's Cruise Ship Environmental Task Force began its work in 2001 and is required to report to the state legislature in June 2003. Alaska collected data during the 2000 summer cruise season and released a draft final report in May 2001. The data collected showed that no ship tested was in full compliance with all standards. For instance, treated blackwater (sewage) exceeded federal standards for fecal coliform in 75 percent of the samples and exceeded standards for total dissolved solids in 86 percent of the samples. In addition, gray water (which is not regulated by federal standards) showed high concentrations of fecal coliform7 which should not be present at all. The air emissions data was less definitive because only ambient monitoring was conducted. In June 2001, the Alaska state legislature passed new legislation regulating cruise ship discharges and emissions. It requires a program of sampling, testing, and reporting of wastewater and air discharges and enforceable standards for anything cruise ships may discharge in Alaska waters.
In the midst of state activity on cruise ships, the U.S. Congress passed a law (Public Law 106-554), in December 2000, that placed new requirements on ships in waters off Alaska. The U.S. Coast Guard took its first penalty action under this new law against the cruise ship Norwegian Sky on May 4, 2001. Lab results of samples of treated effluent discharges showed fecal coliform counts of 700,000 per 100 milliliters and total suspended solids (TSS) of 27,000 milligrams per liter. Federal standards are 200 fecal coliform per 100 milliliters and 150 milligrams per liter of TSS. A third citation was issued in June 2001. These and other data collected in Alaska suggest that the current marine sanitary devices (MSDs) that ships use to treat blackwater may not always be effective, especially as MSDs age.8 The discharge standards were adopted in 1976, based on the technology in use at the time.
On the industry side, a year after the Florida-Caribbean Cruise Association signed a Memorandum of Understanding regarding environmental practices and policies with Florida, the International Council of Cruise Lines (ICCL) announced in June 2001 that its members had adopted mandatory environmental standards for all association cruise ships. The standards, which specify acceptable waste management methods, cover graywater and blackwater discharges; hazardous chemical waste such as photo processing fluid and dry-cleaning chemicals; unused and outdated pharmaceuticals; and used batteries and fluorescent and mercury vapor lightbulbs.
1 The U.S. Oil Pollution Act of 1990 set a phase out schedule (by ship size, age) of oil shipments in U.S. waters in single-hulled ships from 1995 to 2015. From January 2015 onward, single-hulled oil shipments are banned in U.S. waters.
2 TBT is an antifouling agent, a biocide, that prevents the growth of algae, barnacles, and other marine organisms on ship hulls. It leaches from the paint, thereby entering the marine environment and accumulates in sediments, especially in harbors and ports.
3 This action was taken under the Basel Convention on the Transboundary Movement of Hazardous Wastes and Their Disposal.
4 Category 3 is an EPA classification for large, ocean-going vessels.
5 Ship Emissions Assessment at http://www.andrew.cmu.edu/~jcorbett/SEA.html
6 U.S. General Accounting Office, Marine Pollution: Progress Made to Reduce Marine Pollution by Cruise Ships, but Important Issues Remain, GAO/RCED-00-48, February 2000.
7 Fecal coliform indicates the possible presence of human or warm-blooded animal waste.
8 U.S. EPA, Cruise Ship White Paper, Aug. 22, 2000.