Debate Heats Up Over Water-Cooled Buildings

On humid days, frigid water piped from the depths of Cayuga Lake keeps everyone cool in the dormitories, classrooms and research laboratories at Cornell University.

Because there’s nothing quite like it anywhere in the world, the school’s new lake-chilled air-conditioning system could someday be a model copied in communities that lie next to oceans or deep inland waters such as the Great Lakes.

“We’re going to a point where the water’s consistently cold. Nobody’s gone this deep in a lake before,” said engineer Lanny Joyce, who resurrected an old idea championed by Cornell as an environmental boon but scorned by Ralph Nader as “an ill-advised boondoggle.”

Reducing Use of Coal

The ecological impact of “lake source cooling” probably won’t be known for weeks at the earliest, but environmentalists of all stripes have been feuding for the greenest high ground since the project began coursing over regulatory hurdles six years ago.

At 425 feet, Cayuga is the second deepest of the 11 fiord-like Finger Lakes in west-central New York--long, slender exclamation marks gouged by glaciers during the Ice Age.

In July, a pipeline strung 2 miles north along the lake bed to a depth of 250 feet began pumping 39-degree-Fahrenheit water to a heat transfer station near Ithaca. Water that far down hardly varies in temperature all year long.

The piped lake water, flowing past heat-exchanging steel plates, absorbs the mugginess in the 12-million-square-foot Ivy League campus. Never mixing with chemically tainted water in Cornell’s central air-conditioning circuit--a 15-mile loop extended down to shore--it is then returned 11 to 16 degrees hotter in the lake’s warm, shallow south end.

The $60-million project will slash the school’s $1.5-million annual electricity bill for air-conditioning by 80%. It will probably pay for itself in a generation. And it should last 75 to 100 years, twice as long as conventional refrigerators.

What’s more, the switch-over trims Cornell’s reliance on electricity generated by coal-burning power plants, and dispenses with chlorofluorocarbons--chemicals in traditional refrigerants blamed for thinning the Earth’s protective ozone layer.

Algae Blooms Feared

But at what cost to the lake?

A tenacious band of residents worries that the nutrient-rich discharge into 9 feet of water will create noxious blooms of algae in a lake basin already dirtied by decades of human interaction.

“It’s like pouring gasoline on a fire,” said Alex Horne, an ecological engineering professor at UC Berkeley who was hired by the Cayuga Lake Defense Fund to evaluate the project. “I don’t think Cornell can well enough prove they’re not going to cause a nuisance.”

Cornell scientists counter that cool, clear water sucked up from the dark depths at a maximum summertime rate of 46 million gallons a day could actually improve the 38-mile-long lake’s turbid southern tip.

“Algae will bloom in that water moved from the bottom, but the concentration of algae will be lower than the surface water that’s being displaced,” said Nelson Hairston, an ecology professor at Cornell who chaired the project’s scientific review committee.

The existing soupiness “might even look a little bit clearer as a result,” he said.

In any case, Hairston added, two nearby sewage treatment plants already send 12 million gallons of treated water into the lake daily “and there aren’t massive algal blooms.”

To protect aquatic life, mesh screens and a 4-watt lightbulb that repels tiny freshwater shrimp were installed above the entrance to the 63-inch-wide pipe. Sprinkle holes in the outfall pipe disperse the warm water over a wide area.

“There is no no-impact solution . . . but Cornell would not want to do anything that would be harmful to the lake,” said Joyce, the project manager, standing next to the roiling shore after a summer storm had barreled through.

“The amount of heat we’re adding each year is equivalent to about four hours of sunlight. We view this as a cold, renewable resource. It’s not like you use a little of it every year and eventually it’s gone.”

The local Sierra Club chairman, John Kaminsky, believes the pipeline will have no discernible effect on lake conditions. He thinks the community would do better to focus on curtailing unchecked pollutants from “non-point sources” like lawns, creeks and storm runoff.

But widespread praise for the project’s environmental benefits has been accompanied by a drumbeat of complaints. Drawing support from Nader, the Green Party presidential nominee, critics contend the permit is not only illegal but could weaken the federal Clean Water Act.

“Federal law says you can’t issue a discharge permit that will cause or contribute to an existing water-quality violation, and all 5,000 acres of the lake’s southern end is impaired,” said Walter Hang, who runs a business here that maps toxic sites around New York.

After obtaining 17 permits from local and state agencies, the project was scrutinized by the Environmental Protection Agency, which had placed the lake’s south end on a list of “impaired water bodies” in 1998. The lake, Cornell argues, falls into a special “need more data” category not covered by federal bans on discharges.

The EPA, hoping to jump-start a national policy to attack non-point-source pollution, asked if Cornell would volunteer to serve as a model to test the concept of “offsets”--reducing pollutants from other, diffuse sources in exchange for its pumping project.

Cornell said no. “We definitely didn’t want to do something that’s quite controversial nationwide and had never been done before,” Joyce said. Instead, the school is offering its expertise in educating the public about ways to cut back on polluting the watershed.

Horne thinks Cornell would mute criticism by agreeing to an “offset.”

“This is one of the best universities in the world, and it’s up to them I think to go the step further,” he said. “This is the normal pollutant trading you would think an advanced society would be doing by now.”

Big Initial Investment

Another critic, recording engineer Rich DePaolo, thinks the project has drawn so much attention because it will set a precedent for not only “whether this type of technology is implemented elsewhere but how impaired water bodies are managed throughout the country.”

So-called non-contact cooling has been widely used in industry for decades but has yet to catch on as an air-conditioning alternative.

A similar system operates in Stockholm, Sweden, drawing water from 60 feet down in the Baltic Sea, and two more are in the works on Lake Ontario--in Rochester, N.Y., and Toronto, Canada. An ocean-water experimentation lab in Hawaii that draws water from 2,200 feet also uses some of the excess energy to air-condition several buildings.

A big up-front investment, despite the promise of low operating costs, often proves a big turnoff, said Joe Van Ryzin of Makai Ocean Engineering in Hawaii, which designed the Cornell pipeline. But he thinks it’s a technology that will prove popular eventually.

“If Cornell were Wall Street investors, they probably would have never built it,” he said. “However, they’re more world and environmentally conscious than Wall Street, and they have the luxury of being able to choose the high road and do the glorious thing.

“If a city is at a location where it can do that, it really is irresponsible not to.”