AUGUSTA – Cruise lines have one year to retrofit their ships to ensure they aren’t leaving water pollution behind when they visit popular ports such as Bar Harbor and Portland.

Cruise tourism is a growing industry in Maine, where the fall foliage and coastal villages are a major draw. This summer, 79 ships are scheduled to visit Bar Harbor alone. And with several thousand passengers showering, swimming and dining aboard each vessel, these floating cities can produce a tremendous amount of waste.

The Maine Board of Environmental Protection unanimously gave final approval Thursday to state rules regulating discharges from cruise ships in port, which will take effect at the start of 2006. The rules regulate both gray water – the water from sinks, swimming pools and washing machines – and a mix of gray water with black water, or water from on-board sewage systems.

Without regulation, ships could be discharging water containing bacteria from sewage that can make beaches unsafe for swimming, as well as substances such as phosphorus from detergents that can promote unnatural algae blooms.

“Our bays and coastal waters are our lifeblood,” wrote a resident of Hancock, urging the state to enact strict rules in hopes of protecting Frenchman Bay, where she often kayaks. “In the distance … sit cruise ships at anchor. I try not to think about what they are spewing onto the waters (legally or not); sewage, gray water, garbage and God knows what else.”

State lawmakers approved the idea of standards for all ships carrying more than 250 overnight passengers during the 2002-2003 legislative session, specifically asking Department of Environmental Protection staff to set standards that are as similar as possible to those already on the books in Alaska, in hopes of easing the burden for cruise lines.

Those standards, approved Thursday, include limits on suspended solids, water acidity, fecal coliform bacteria, chlorine and biochemical oxygen demand – a means of measuring how much oxygen in the water is available to fish and other organisms. Cruise lines will be responsible for sampling their effluent and having it tested by certified laboratories. Ships also will be required to keep a record of all discharges and to immediately report any accidents to the state.

During debate over the standards, the International Council of Cruise Lines, which represents a majority of the ships that visit Maine, cited its self-regulation. The organization does not allow its members to discharge effluent within four miles of any shoreline.

However, a small number of ships that visit Maine are not members of ICCL. As many as nine ships nationwide are equipped with new water treatment systems that are built for continuous discharge, much like a municipal sewage treatment plant on shore. While cruise lines tout the ships as releasing perfectly clean water, Maine’s rules will ensure that the systems are operating properly, according to the DEP.

By next summer, Maine’s cruise ship discharge rules will be among the strictest in the nation. But in the meantime, students from Mount Desert Island – the state’s most-popular cruise destination – have taken on the responsibility for monitoring possible pollution.

The MDI Water Quality Coalition, a nonprofit group based in Bar Harbor, has worked with local students to sample harbor water and determine the environmental impact of cruise ships.

Last summer, when the town saw a record 87 ships, students worked with the local harbor master to sample water within a few yards of the vessels. Most of the ships (a majority of which were ICCL members) were leaving no pollution behind, Tifin Calcagni, outreach director for the coalition, said Thursday.

However, the presence of two ships coincided with increased levels of bacteria in the harbor, in one instance, right next to the town beach, she said. Both ships solved the problem before their next visits to Bar Harbor, she said.

“Neither were big problems, but it was a good thing we were looking,” Calcagni said, adding that the sampling program will continue this summer.

No one opposed the discharge rules Thursday. However, some Maine residents have called for stricter regulation in areas that are ecologically sensitive.

Residents from the Casco Bay region have asked the DEP to consider naming the bay a “no discharge” zone in hopes of protecting a small ecosystem with heavy traffic and limited ability to flush out pollution. Other states have such resource protection zones, but none currently exist in Maine. Casco Bay will likely be a pilot project, with additional requests coming from other coastal areas, according to Pam Parker of the DEP Bureau of Land and Water Quality.

For more information about the MDI Water Quality Coalition testing program, e-mail tifin@mdiwqc.org or call (207) 288-2598.