The proposed construction of wind turbines on Fox Hill in Ulysses Township will have no noticeable affect on the dark skies at Cherry Springs according to a study released last Thursday by the Department of Conservation and Natural Resources.

DCNR commissioned the study from an internationally respected lighting consultant - Clanton and Associates of Boulder, Colo. - after opponents of the wind power project and some amateur astronomers who use the park raised concerns that flashing red lights on top of the turbines could create light pollution that would diminish the quality of stargazing at the park.

DCNR has invested heavily in developing the park as a Dark Sky Preserve, which has formed the centerpiece of tourist promotion for the Pennsylvania Wilds Region.

DCNR Secretary Michael DiBerardinis said, "DCNR has the responsibility to protect the irreplaceable dark skies of Cherry Springs State Park - a facility that has garnered national attention for the quality of its astronomical viewing opportunities. After consulting with the International Dark Sky Association, we sought this review to understand what the impacts of this proposal might be, and to identify any mitigation measures that might be desirable or possible."

The study - which used the formula most likely to overestimate the impact of the lighting and which assumed a "worst case scenario" in which all the flashing lights would be on at the same time - concluded that "the expected increase in sky brightness should fall in a range between 0.003 percent and 0.005 percent. In our experience, observatories consider an increase in overhead sky brightness of 2.5 percent of less to be negligible. Because our maximum estimate of 0.005 percent falls well below this increase, we expect the sky glow impact to be unnoticeable."

The study also examined the "line of sight impact" - whether or not the flashing lights would be visible from the astronomy field at Cherry Springs.

Some had alleged that the turbines would be so tall, the flashing red lights would themselves interfere with stargazing at Cherry Springs apart from the alleged light pollution itself.

The study concluded this too is not an issue.

"From the observation field in park, the trees will block a direct view of obstruction lights during full foliage," the study concluded. "In the winter, when the leaves are off of the trees, the lights may be viewed from some angles. Because these points will be near the horizon, and still below the tree line, we feel that they will have a very minimal, if any impact throughout the year on astronomical observations."

The greatest threat to the dark skies at Cherry Springs is actually lighting that's already in place - specifically private security lights that are unshielded, flood lights and other unshielded area lights at Denton Hill State Park and sports field flood lights and park lights in Galeton.

The study outlines specific examples with photos of offending lights in each instance and gives recommendations on how the impact on the dark skies can be minimized.

The study also notes that currently the greatest amount of light pollution reducing the quality of the night skies at Cherry Springs comes from the town of Coudersport, which according to their calculations, increases the zenith sky glow at Cherry Springs by 0.328 percent. Coudersport's light pollution is followed (in descending order of impact) by Galeton at 0.278 percent, Emporium at 0.071 percent, Austin at 0.069 percent, Wellsboro at 0.065 percent and Port Allegany at 0.052 percent.

DCNR said the wind turbine project developer AES "has been very cooperative and responsive during the review. The company retained its own lighting consultant and shared detailed project information and its own analysis with DCNR's consultant.