March 2010, Vol. 22, No.3

Waterline

Clean Drinking Water in the Air

Having a drink of water at 9000 m (30,000 ft) just got a little safer. On Oct. 5, 2009, the U.S. Environmental Protection Agency (EPA) issued the final version of the Aircraft Drinking Water Rule (ADWR) to ensure a reliable and safe source of drinking water for U.S. flights.

The rule establishes requirements for coliform sampling, best management practices, public notification, monitoring, and operator training for drinking water supplies in the air-carrier industry, according the EPA Web site.

“EPA has taken this step to make sure the public has drinking water that meets standards, both in the air and on the ground,” said Peter S. Silva, assistant administrator of EPA’s Office of Water, in a news release. ADWR tailors existing health-based drinking water regulations to fit the unique characteristics of aircraft public water systems, the news release says.

In the United States, drinking water is regulated cooperatively by EPA, the U.S. Food and Drug Administration (FDA), and the Federal Aviation Administration (FAA). EPA regulates water quality in public systems that supply water to airports and drinking water once it is on board the aircraft. FDA is responsible for regulating the systems used to transfer water onto aircraft. FAA oversees operation and maintenance programs of the aircraft, which include the potable water system.

Aircraft water systems already were subject to the National Primary Drinking Water Regulations under the Safe Drinking Water Act. ADWR amends these regulations, building on existing operations and maintenance programs and focusing on onboard water systems.

In 2004, EPA found all aircraft water systems to be out of compliance with the National Primary Drinking Water Regulations. The air carriers responded by saying it was not feasible for them to comply with all of the monitoring required in the existing regulations, because the regulations were designed for traditional, stationary systems, the EPA Web site says. ADWR provides air carriers with a feasible way to comply with these regulations.

Aircraft fly to multiple destinations in a day and can take on water from airport watering points through temporary connections from any of their destinations. The rule only addresses aircraft within the United States; however, EPA also supported an international effort led by the World Health Organization (Geneva) to develop international aircraft drinking water guidelines, EPA’s Web site says.

Drinking water safety depends on the quality of water taken on board from multiple sources, care used to transfer the water, and operation and maintenance of the onboard water system and the water-transfer equipment, such as water cabinets, trucks, carts, and hoses, the EPA Web site says. For more information, see www.epa.gov/ogwdw000/airlinewater/index.html.

 

Simple System Converts Wave Energy to Electricity

Homes in Orkney, Scotland, are receiving a new kind of renewable energy. In November, Scotland’s First Minister Alex Salmond officially launched the world’s only hydroelectric wave energy device, known as Oyster™, at the European Marine Energy Centre (EMEC; Orkney). The device is producing power that is being fed into the national grid to power homes, according to a news release from Queen’s University Belfast (Northern Ireland). The system produces power by pumping high-pressure water to its onshore hydroelectric turbine.

Oyster, a seabed-mounted oscillating wave surge converter, captures energy from near-shore waves in depths between 10 m and 15 m, according to the university Web site. The modular system can be arranged in clusters to produce up to 5 MW, and clusters can be combined into 100-MW arrays, the Web site says. A farm of 20 devices would provide enough energy to power 9000 three-
bedroom family homes, the news release says.

The system includes no moving parts, and all electrical components reside onshore. Oyster consists of a hinged flap connected to the seabed. The flap moves with each wave, driving a hydraulic piston to deliver high-pressure water to an onshore turbine, the news release says. The system features minimal environmental impact and quiet operation, the Web site says.

Smaller, less frequent waves found near the shore improve the durability of the system, and its flexibility of movement enables it to go under waves, according to the Web site of Aquamarine Power Ltd. (Edinburgh, United Kingdom), a company formed specifically to develop Oyster.

Queen’s University Belfast helped create the technology behind the system between 2002 and 2004. The system was developed by principal investigator professor Trevor Whittaker of Queen’s School of Planning, Architecture, and Civil Engineering; senior research associate Matt Folley at Queen’s University Belfast; and professor Stephen Salter of the University of Edinburgh. Under the current joint agreement, Queen’s University performs the hydrodynamic testing for Aquamarine.

“We are continuing to work with our partners in Aquamarine Power and the EMEC to develop the next generation of Oyster, by providing testing opportunities at Queen’s large wave tanks facility in Portaferry [Northern Ireland],” Whittaker said in the news release.

The testing is funded, in part, by the university’s Institute for a Sustainable World. Further funding is being provided to Aquamarine Power for the development of Oyster 2, which could be installed within 2 years, according to Salmond. The next-generation Oyster demonstration farm, scheduled for production in 2011, could displace up to 2720 Mg/yr (3000 ton/yr) of carbon, according to Aquamarine’s Web site.

 

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