Critics say HB80 would reduce protections set out in a 2006 citizen initiative that required cruise ships to meet state water quality standards when dumping wastewater.
Parnell's Environmental Conservation commissioner, Larry Hartig, has said the measure would align rules for cruise ships with those for others that get discharge permits from the agency.
HB80 would require that cruise ships discharge wastewater in a manner consistent with applicable state or federal law. It would strike the more stringent requirement that discharges meet state water quality standards at the point of discharge.
It also would allow authorization of mixing zones if ships meet certain standards for treatment of discharge.
Hartig testified that his department can set restrictions for mixing zones. Michelle Bonnet Hale, director of the department's Division of Water, has said the department doesn't currently plan to monitor at the edge of mixing zones but has the authority and funding to do so, if necessary.
HB80 stems from a preliminary report by a science advisory panel charged with looking at pollution from the ships and pollution control. The panel, in the report, found none of the advanced systems on ships operating in Alaska waters could consistently meet water quality standards at the point of discharge for "constituents of concern," ammonia, copper, nickel and zinc.
It also identified "little additional environmental benefit" to be gained by lowering the current permitted effluent limits to water quality standards at the point of discharge. It said a dilution model, developed by an earlier panel, and other studies show concentrations lower than the water quality standards within seconds following discharge of the treated wastewater.
One of the panelists, marine ecologist Michelle Ridgway, testified against the bill, saying she disagreed with several of the findings, including that fish and marine mammals would be protected under a cruise ship general permit.
Ridgway said an environmental benefit would be derived and the dilution model and studies were done under "very specific and narrow" assumptions and didn't adequately consider the unique features of coastal Alaska oceanographic conditions.
Rep. Paul Seaton, R-Homer, in a newsletter to constituents Monday, said his concerns with the bill include "the habitat impact of multiple vessels having overlapping mixing zones, the fact that this legislation stymies the citizen's initiative, the lack of a critical habitat discharge prohibition and the possibility this will result in discharge quality backsliding."