Cruise ships visiting Alaska are dumping less wastewater into the Inside Passage due to a state law passed in 2001, according to the state Department of Environmental Conservation.
On Monday, DEC released a report assessing cruise ship and wastewater impacts in Alaska.
It notes that advanced wastewater treatment systems installed on the cruise ships over the last two and a half years have "dramatically improved" the quality of wastewater dumped from most cruise ships.
Wastewater dumped from smaller cruise ships and ferries in the Alaska Marine Highway System, however, still frequently exceed Alaska water quality standards for ammonia, free chlorine, fecal coliform, arsenic, copper, nickel, selenium and zinc, according to DEC.
Cruise ship travel in Alaska has increased almost three and a half times since 1990.
In 1990, about 235,000 travelers visited Alaska on cruise ships. By 2003 that number increased to about 800,000.
Juneau Democratic Rep. Beth Kerttula, one of the main architects of the 2001 cruise ship legislation, applauded the industry and the DEC for its efforts in reducing marine pollution.
Kerttula said the report shows copper, nickel, zinc and ammonia are still appearing in small amounts of wastewater dumped by some cruise ships.
"We're not 100 percent," she said. "But oh, my God, every other place in the world would love to have these standards."
Kerttula traveled to Washington state this week to testify before its Legislature on a proposed law similar to Alaska's. Rep. Mary Lou Dickerson, a Seattle Democrat, proposed the bill this session, which had its first hearing this week in the state's House Fisheries, Ecology and Parks Committee.
Dickerson said the bill was partly prompted by the discovery last May that a ship called the Norwegian Sun dumped 40 tons of human waste into the Strait of Juan de Fuca, near the Washington-Canada border.
"I think it's going to have a rocky go this year," Dickerson said. "The industry is fighting it tooth and nail as it did in Alaska."
She said the difference between her bill and the Alaska law is it would not allow dumping graywater, which generally constitutes nonsewage water, such as laundry, bath and sink water.
Alaska law allows dumping of graywater if the vessel is traveling at 6 knots and is one nautical mile from shore.
The report issued by DEC noted that smaller cruise ships dumping wastewater in Alaska do pose some risk to the marine environment.
"Due to the high concentration of fecal coliform (sewage water), the effluent from some small ships may pose a risk to human health in areas where aquatic life is harvested for human consumption," the report said.
The cruise ship law passed in 2001 requires smaller ships carrying fewer than 250 passenger to come into compliance with wastewater standards by March of 2004, according to Caroline Morehouse, an environmental engineer with DEC.
Ships that are not in compliance with the law by then must submit a proposal to DEC, outlining in detail when they will come into compliance with the law, she said.
"They have the option to submit an interim protection plan to tell us their schedule for compliance," Morehouse said. "They would have an extension to get into compliance but they have to show that they are moving toward that."
Wastewater samples from small and large cruise ships showed no evidence of hazardous materials, such as photography lab chemicals, according to DEC.