Pollution Patrol

The southern shelf of Cayuga Lake is polluted. It has been polluted for decades.

Swimming has been forbidden at Stewart Park since 1962, when a child drowned because he could not be found when he went under in the silt-laden water. The Cornell Lake Source Cooling project has been in operation since 2000. Local environmentalists have identified the LSC project as a significant contributor to the pollution of the south end of Cayuga Lake, and they want the project either shut down or modified to eliminate or ameliorate its purported effects.

"I don't wish to single out Cornell in any way, shape or form," said activist Walter Hang, who owns and operates Toxics Targeting.

Hang looks at the project in both a local and national context.

"Locally, Cornell applied for discharge [State Pollutant Discharge Elimination System; SPDES] permit for Lake Source Cooling," he said. "Nationally, it's recognized that in important water basins, existing problems are worsened by additional permits."

Hang noted that the Clean Water Act focuses largely on limiting point sources - pollution that originates at a specific location - with only one section dealing with non-point sources. It is quite clear to him that the intent of the legislation is to eliminate point sources of pollution.

The pollutant in question with regard to LSC is phosphorus. In most ecosystems plant growth is limited by the amount of phosphorus present, and an ecological balance is struck between rates of plant growth and levels of grazing based on the naturally occurring level of phosphorus in the system. Pollution is the disruption of this balance.

Cayuga Lake is a monomictic lake, which means that it is thermally stratified from early summer through the fall and then mixes from top to bottom from the late fall to the spring. During the stratified period, a sun-lit, wind-mixed layer called the epilimnion forms. Most plant growth occurs here. Macrophytes (multi-cellular plants, both rooted and otherwise) and algae draw phosphorus, carbon and nitrogen compounds from the water column, and convert them into organic matter, which then sinks down through the water column.

As the organic matter sinks, it is set upon by bacteria and begins to decay into carbon, nitrogen and phosphorus compounds again. When it reaches the thermocline, where water temperature and therefore density change rapidly, the rate of descent of the organic "rain" slows, and it accumulates at higher concentrations. The layer below the thermocline-the hypolimnion-is therefore richer in phosphorus than the epiliminion. The LSC system removes cold hypolimnion water from the lake, cools buildings on Cornell's campus, and returns it to the epiliminion of the lake.

Hang sees the discharge of the phosphorus-enriched hypolimnion water into the surface mixed layer of the lake as one discharge too many.

"Wastewater treatment is already permitted," he said, adding that these plants are working to reduce their contributions. "The Ithaca wastewater treatment plant has recently cut its phosphorus by 58 percent."

He noted that in the BACI (Before-After/Control Impact) report issued by Cornell to comply with state Department of Environmental Conservation regulations, phosphorus levels measured at monitoring Site 2 - which was chosen specifically to monitor the Ithaca plant's outfall - declined. The activist added that Cayuga Heights wastewater plant is also trying to reduce phosphorus levels in its discharge.

In a recent meeting with Environmental Protection Agency Administrator Lisa Jackson, Hang presented her with a proposal to change the location of the LSC discharge pipe. He would like to extend it into deeper water, i.e. into the hypolimnion from which the water is originally drawn, or to have Cornell treat the LSC water to remove the phosphorus before it is returned to the epiliminion.

"The EPA offered New York State money to work on this," Hang said, "and they didn't take it."

He further claims that the DEC wrote, but did not hand in, a grant proposal that would have provided money to fund work on this topic. Hang also pointed out that DEC environmental scientist Cliff Callinan, an authority on Finger Lakes water quality, recommended against issuing a permit for the LSC system, but he was "cut out of the process," according to Hang. Callinan's monumental "Water Quality of the Finger Lakes" was published in 2001 and is available online at the DEC Web site at www.dec.ny.gov/lands/25576.html.

Callinan was unavailable for comment by press time.

Steve Penningroth, a chemist and founder of the Community Science Institute, is baffled by the controversy over LSC.

"We have been taking samples in a transect across the lake in both the epiliminion and the hypoliminion" he said. "The concentration of phosphorus in the hypoliminion at 60 meters (approximately 200 feet) is 8 micrograms per liter."

This is the water, he noted, that enters the LSC system.

"The Cayuga Heights wastewater treatment plant is permitted to emit 500 to 1000 micrograms per liter of phosphorus," Penningroth said. "Ithaca [wastewater treatment plant] is around 200 to 500."

The chemist has not read the BACI report, but he has been told that the only monitoring site to show any impact was Site 7.

"That one is near influence of the LSC outfall, the Cayuga Heights treatment plant and Stewart Park," Penningroth said.

Penningroth's Community Science Institute has been analyzing samples from two tributaries that enter the lake near Stewart Park.

"One goes under the railroad tracks and into the lake near the visitors' center," he said. "The other one is on the opposite side of the park and actually enters Fall Creek just before it goes into the lake."

The institute has monitoring sites at the mouths of both tributaries.

"Both sites have elevated total phosphorus," he said.

Levels at these locations have been measured at 50 to 70 micrograms per liter.

"Fall Creek water is 30 micrograms per liter," Penningroth said. "That's two or three times lower than these tributaries."

He has no idea what the source of phosphorus in these tributaries might be. The eastern tributary drains off the hillside along Sunset Drive while the western stream emerges near Ithaca High School after running through residential neighborhoods like Highland and Upland roads.

The data being collected by the Community Science Institute indicates that water in Fall Creek has phosphorus levels that are triple those emerging from the LSC discharge pipe.

"The lake source cooling discharge is actually diluting the phosphorus in the Fall Creek water," Penningroth half-joked.

While Hang is focused on limiting point sources of phosphorus pollution, Penningroth's data is suggesting that non-point sources are also important.

"In Fall Creek there is loading from agriculture upstream; that's a non-point problem," the scientist said. "You can compare it to Six Mile Creek. That watershed is heavily forested, and it's got half the phosphorus of Fall Creek."

Penningroth compared both watersheds to Salmon Creek.

"It has lots of phosphorus when it rains," he said, "and it's in the form of dissolved phosphorus, suggesting fertilizer spikes. The levels are lower than Fall Creek when it's dry though."

The agricultural community is quick to take umbrage when they are identified as sources of phosphorus and nitrogen pollution. They point out that while their application of fertilizer is highly regulated, the application of nitrogen and phosphorus compounds in the name of lawn care is completely unregulated.

LSC is a point source of phosphorus, from Penningroth's point of view, only in the bureaucratic sense.

"Loading regulations apply to point sources under the Clean Water Act," he said. "When you load a system you import exogenous sources of phosphorus, like farms and treatment plants.

"Does lake source cooling fit that definition?" Penningroth added. "It is really just recycling phosphorus from deep to shallow; it's already in the lake."