A state court has ruled the Department of Environmental Conservation can order Entergy, the owner of Indian Point, to stop using massive quantities of Hudson River water to cool the non-nuclear side of the facility.

Over the years, activists have argued that billions of fish are killed when the plant sucks in water from the river. The environmental group Riverkeeper and the New York State Department of Environmental Conservation want Entergy to reuse the water, rather than constantly draw it from the Hudson.

"We just did a study last year that showed that 10 out of 13 signature species in the Hudson are in decline," says Phillip Musegaas, of Riverkeeper.

One possible way for the plant to reuse the water is to construct cooling towers. However, Entergy spokesperson Jerry Nappi says that would be very expensive and may not be practical. Nappi adds the ruling is only a partial victory for the environmentalists because the court has yet to specify the technology that should be used to cool the plants. Hearings on the cooling process are not expected to begin until next year.