Ban on cruise ship sewage discharges near shellfish beds

The NorthWest CruiseShip Association, an organization representing the cruise ships traveling to and from the Port of Seattle, has agreed to prohibit discharges of treated sewage within a half-mile of shellfish beds as recommended by the state Health Department.

Dumping of raw sewage within Puget Sound and the Strait of Juan de Fuca south of the international boundary with Canada is prohibited, under a voluntary arrangement struck in 2004 and updated annually by its signers -- the cruise association, the Port of Seattle and the state Ecology Department.

Under the agreement, cruise vessels can use advanced sewage treatment systems to strain the solid material from the raw sewage. Once that's done, the rest is treated to levels similar to those achieved by King County's wastewater treatment division and can be discharged into Puget Sound, including at the dock.

Sewage sludge cannot be dumped closer than three miles from shore, according to U.S. law, but the cruise lines have agreed to international guidelines that prohibit sewage sludge dumping within 12 miles of shore. This year, 211 cruise ships are expected to call at the Port of Seattle.

The average Alaska-bound cruise ship generates about 28,000 gallons of sewage sludge during the seven-day jaunt from Seattle, according to port staff. The port is studying whether it would be feasible and advisable to truck the sewage to a treatment plant rather than dumping it in the ocean.

The cruise lines have also recently agreed to stop discharging treated sewage when gastroenteritis cases exceed 2 percent of passengers or crew for this season.

The amended agreement can be found at Ecology's cruise ship Web site at www.ecy.wa.gov/programs/wq/wastewater/cruise_mou/index.html.

The Environmental Protection Agency released a draft study of cruise ship waste in December that found cruise ships' treated sewage contains levels of chlorine, phthalates, ammonia, copper, nickel and zinc that greatly exceed the EPA's water quality criteria, even after the sewage was processed by the most advanced systems. Ammonia adds to the risk of fueling algal blooms and "dead" zones posed by cruise ships and their thousands of passengers' waste.