JUNEAU — While environmentalists are quick to complain about cruise ships dumping waste in the ocean, officials say Alaska ferries have even more lenient rules for treating wastewater.
State ferries use water treatment systems that were standard in the 1970s, state Department of Environmental Conservation cruise ship program specialist Ed White said.
Eight of the 11 state-owned ferries use chlorine to kill bacteria and then grind waste before discharging that slurry with used water from sinks, toilets and showers, White told the Juneau Empire — an approach commonly used by cruise ships until 2000. That's when officials found the systems didn't perform as well when compared to more advanced wastewater systems, he said.
The state transportation department, which operates the ferries, has been working to upgrade systems on board, he said.
The five largest ferries, with overnight lodgings for more than 50 people, fall under state regulations for small cruise ships. While the Department of Environmental Conservation, or DEC, requires regular sampling of treated wastewater from large cruise ships, samples for small cruise ships are required only twice a year, he said.
Cruise ships discharge far more wastewater than ferries. In May, the 3,500-passenger Norweigan Jewel, which visits Juneau regularly, discharged about 184,000 gallons of treated wastewater a day into Alaska waters, according to DEC. The state ferry Columbia discharged about 15,000 gallons a day that month.
The ferries Aurora, LeConte and Tustumena are too small to be regulated by the state but must meet federal standards that require they carry the chlorine treatment systems they do.
"They're meeting the federal requirements, but the federal requirements were written 40 years ago," White said.
Chlorine is considered toxic to marine life, and small cruise ships are limited in how much chlorine can remain in treated wastewater, he said. Ferries have been installing de-chlorination units, he said.
The remaining three ferries use holding tanks to collect waste and pump it ashore, state transportation department spokesman Jeremy Woodrow said.
Coast Guard rules prohibit the dumping of untreated wastewater within about 3.5 miles of land. Since ferries use chlorine tablets to treat the water first, they are allowed to discharge anywhere in Alaska waters, as long as they are underway, USCG spokeswoman Jenn Ferreira said.
New DEC rules allow for some of the large cruise ships to discharge while docked at downtown Juneau. Ferries do not pass through that area.