Environmental concerns are brewing in and around Lake Carnegie, Princeton’s largest lake.

The lake suffers from low oxygen content and a mercury level high enough to prompt an advisory on fish consumption, said Denise Patel, campus organizer for New Jersey Water Watch, an environmental activist group.

Most of the northeastern seaboard has mercury-related problems in its waterways, but Ms. Patel said New Jersey’s are the worst in the region.

“New Jersey has a lot of environmental problems stemming from its long legacy of industrial pollution to more recent problems related to overdevelopment,” she said.

In addition, New Jersey’s status as the most densely populated state in the country only exacerbates the problem.

“Princeton happens to fall into an area that is being developed faster than any other part of the state,” she said.

Neighboring West Windsor Township has had the highest rate of development in the state in recent years. Rapid development can stress local waterways.

However, Lake Carnegie’s water-quality problems are not due to large industrial plants, but to other, more local environmental conditions.

“Lake Carnegie’s large mercury and phosphorous load comes mainly from nonpoint sources such as litter, fertilizers, pesticides, and oil and gas from cars,” said Peter Jaffé, professor of civil and environmental engineering and department chair.

Fertilizers and pesticides are a source of nutrients in the water, he said, which can cause oxygen-depleting algal blooms.

Professor Jaffé, who lectures on water-pollution technology and conducts research on radionuclides in water, said nonpoint source pollution is difficult to deal with and that buffers between water sources and agricultural or activity zones are necessary.

Efforts made at the Stony Brook-Millstone Watershed Assoc., a local group, may lead to decreased levels of mercury in the future.

George Hawkings ’83, executive director of the association, said that the amount of sedimentation in the lake is “slower than expected because of settling ponds built on Stony Brook river and tributaries.”

Such ponds prevent unnecessary fertilizer runoff and pesticides from filling the lake, he said. Under Ms. Patel’s direction, Princeton Water Watch is working to improve local water quality through education and community projects.

Service projects include removing debris from riverbanks, collecting water samples to test for types of pollution, mapping local waterways, and offering environmental education in local schools.

Catherine Chou ’06, president of the Princeton chapter, said the group sponsors four cleanups a year of the Delaware and Raritan Canal, which runs behind Carnegie Lake, and many other stream monitoring programs.

“We always welcome new volunteers, and hope students get involved to really make a difference in their community,” Catherine said.

For more information about New Jersey Water Watch, visit www.princeton. edu/~njh2o/join.html.