JUNEAU, Alaska -- The Alaska Senate on Tuesday approved a Parnell administration measure to roll back cruise ship wastewater standards that were approved by voters in 2006. The vote was 14-6.

The legislation, already passed by the House, is the first bill to clear both the House and Senate in the 2013 legislative session that began just over a month ago.

All Senate Republicans voted for the measure, along with Democrat Lyman Hoffman.

Democrats Bill Wielechowski, Dennis Egan, Hollis French, Berta Gardner, Johnny Ellis and Donny Olson voted against it.

House Bill 80 allows the cruise industry to indefinitely discharge ammonia, a product of human waste, and heavy metals, dissolved from ship plumbing. Such discharges would have been banned starting in 2015 by that voter initiative passed in 2006 and later revised.

The legislation also ends the work of an advisory panel on cruise ship wastewater. The panel was created by a 2009 law. Its task was to investigate whether the technology exists to meet the 2006 standards.

Sen. Cathy Giessel, R-Anchorage, said the new legislation was the result of years of research, and technology has advanced the level of treatment but no new methods are on even on the horizon to lower levels of copper, zinc, nickel and ammonia at the point effluent is discharged. She said the measure will not lower Alaska's water quality standards.

Ammonia can contribute to algae blooms and harm shellfish. Copper, a heavy metal, has been shown to hurt the homing sense of salmon -- their ability to smell -- in freshwater.

Large cruise ships no longer discharge raw sewage, Giessel said, and the state Department of Environmental Conservation will still require the industry to use advanced treatment systems that produce cleaner effluent than most municipalities do.

"The intent of HB 80 is to apply a consistent environmental approach to all wastewater dischargers in Alaska -- cruise ships, municipalities, fish processors and others," she said.

The initiative for large cruise ships required them to meet state water quality standards -- meaning the water had to be clean enough not to harm life -- at the point that treated wastewater is discharged from the ship, not after it is diluted in seawater.

The bill just passed allows for the standards to be met at the edge of "mixing zones," -- where the effluent starts to dilute in the sea -- not at the point of discharge. Mixing zones for effluent from municipal treatment facilities can be tested, but ships continuously dump wastewater while moving, so the water quality in their mixing zones is based on computer "modeling," not actual sampling.

Democrat Olson -- who is from Golovin, near Nome, and this year is aligned with the Republicans -- said he had been deluged with emails of concern from his district and could not support the GOP-backed measure.

Alaska's cruise industry isn't just in Southeast anymore, he said.

"Their concern is that we've seen more and more cruise ships coming around the Northwest Passage, coming on down the Bering Straits, and the people from Savoonga, the people from St. Lawrence Island are very concerned about what is going on and are watching this bill very closely," Olson said.

His region already was hit by the end of a state program that gave communities a voice in managing projects and activities along their coasts. The cruise ship wastewater bill is an additional insult, he said.