Keeping Paradise Green
Keeping Paradise Green
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Keeping Paradise Green
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In Alaska, cruise lines and government agencies are looking for ways to make cruise line wastewater treatment cleaner through new regulations that can be managed through a pilot plan that aims to recycle wastewater on cruise ships.

Each year, cruise ships carry hundreds of thousands of people through the clear waters and breathtaking scenery around Alaska — and generate millions of gallons of wastewater.

Currently, wastewater generated is treated effectively — achieving around the same cleanliness as many direct discharge municipal wastewater treatment plant effluents — and must be dumped at least 12 nautical miles offshore. Still, residents in Alaska became concerned about ocean dwellers along their shores as aquatic life is more sensitive than humans to common contaminants found in wastewater. They wanted something done to ensure ocean-dwelling creatures would not be harmed or eventually become extinct because of cruise liners dumping potentially toxic wastewater along the shores.

Although an interim permit gives cruise liners until 2010 to comply, a 2008 environmental initiative in Alaska requires cruise ships to meet the strictest worldwide limits for ammonia, copper, nickel and zinc effluent limits.

The Alaska Department of Environmental Conservation (DEC) commissioned a team of consultants, including Burns & McDonnell, to conduct a study in February 2009 to assess ships’ existing capabilities, technologies and effluent levels, and if the technology exists to improve their treatment potential.

“The limits set by the new law results in a quality of water that’s even better than what we drink,” says Reinaldo González, Burns & McDonnell project manager. “Cruise liner owners were adamant that meeting the new limits is not possible.”

But the study found that even though it could take several years, achieving those limits is possible.

A logical place to start is evaluating where contaminants come from — whether it be hair salons, photo shops, cabin showers or other sources — and aim to reduce or remove them at the start. Cruise liners also could evaluate graywater, which does not contain biological or chemical waste, for reuse in ways appropriate for each vessel, such as floor rinsing before sanitary cleansing.

“At this point, reusing graywater is just an idea to consider. As each cruise line owner gets more detailed in his or her plan for improved wastewater treatment, specific and appropriate uses for graywater can be identified,” González says.

Once the level of contamination is reduced and the amount of recycled water is optimized, possible technology and equipment upgrades can be explored. That could be the trickiest part of all. While land-based technologies have the capability, they have not been used on cruise ships before.

“The greatest challenge about this project is adapting the technologies,” González says. “Not only would we be challenged by the smaller space to somehow implement land-based processes, but we also would be working off a different set of standards and regulations.” Burns & McDonnell’s team recommends installing a pilot plant before any full-scale upgrade is installed to ensure adequate function and that the equipment meets specific marine standards.

“Meeting the new limits can be done,” says González. “It’s just a matter of when.”

For more information, contact Reinaldo González, 816-822-3185.

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