Acciona submits its ‘final’ statement; Developer ignores consultant’s views on noise analysis 

CAPE VINCENT – The developer of St. Lawrence Wind Farm has eliminated two wind turbines for noise and wetland considerations, but it ignored the conclusions of the town’s consultant on noise analysis in order to maintain a 51-turbine array.

Acciona Wind Energy USA submitted the possible Final Environmental Impact Statement to the town Planning Board on July 28. The board will meet at 7 p.m. Wednesday at the Cape Vincent Recreation Park, 602 S. James St., to decide whether to accept the statement and deem it complete.

The developer’s consultant, David M. Hessler of Hessler Associates Inc., Haymarket, Va., maintained that his handling of noise measurements and analysis were proper. But the town’s independent consultants, Gregory C. Tocci and William J. Elliot of Cavanaugh Tocci Associates, Sudbury, Mass., found fault with the analysis.

Mr. Hessler used sound levels that were an average of 44 decibels during the summer and 37 decibels during the winter when the wind is blowing.

According to a state Department of Environmental Conservation guideline, noise exceeding six decibels above ambient is considered intrusive or objectionable. Hessler Associates’ analysis showed the array of turbines would not create noise above six decibels above ambient at any residence.

“All residences, whether participating or not, lie outside of the 42 dBA sound contour line and will be short of the 6 dBA NYSDEC threshold,” the developer wrote in the statement. “However, wind and weather conditions (i.e., temperature inversion and low level jetstreams) may develop from time to time causing Project sound levels to increase, sometimes substantially, over the normal predicted level.”

Those periods should be short, the statement said, although it noted that the cumulative effects if both St. Lawrence Wind Farm and BP Alternative Energy’s Cape Vincent Wind Farm were built would push noise levels above the DEC guideline. The statement predicted higher levels for six participating and 37 nonparticipating residences.

In letters to town engineer Kris D. Dimmick, of Bernier, Carr & Associates, Watertown, Mr. Elliot and Mr. Tocci repeated criticism of the noise analysis Mr. Elliot described to town officials in February. He said then that Hessler’s data did not statistically support the correlation between wind speed and noise. To get a stronger correlation, the wind speed and noise levels would have to be taken at the same location, but they were not, he said.

In a May 14 letter, the two disputed the background noise levels that Mr. Hessler assumed through his regression analysis. Mr. Elliot and Mr. Tocci had measurements that averaged five decibels below the levels Mr. Hessler predicted in his regression analysis. They recorded the sound levels at specific wind speeds.

If ambient noise levels have been overstated in the impact statement, it will allow higher levels of noise from turbines without violating DEC limits.

“Using a regression to associate background sound with wind speed frequently underestimates wind turbine noise impact by permitting frequent conditions where turbine sound significantly exceeds the NYSDEC margin of 6 dBA,” Mr. Elliot and Mr. Tocci wrote.

In a rebuttal letter June 21, Mr. Hessler said the actual measured noise values were too strict.

“Using these overly conservative values in the various wind speed bins as bases for evaluating the nominal impact threshold of a 6 dBA increase would undoubtedly and unrealistically suggest that adverse noise impacts will occur on a widespread basis over the entire project area and beyond,” Mr. Hessler wrote.

In a July 15 letter, Mr. Elliot and Mr. Tocci again argued against using the regression analysis and for the actual measurements from wintertime.

Using the measurements “leads to an impact threshold based on the NYSDEC policy that is approximately 5 dBA lower than the impact threshold estimated by Hessler” at 13.4 miles per hour, they wrote. “It is at this wind speed that Hessler indicates the greatest potential noise impact may occur.”

They reiterated that the Hessler analysis does not show a “conclusive relationship” between sound and wind speed. As a result of the averages used by Hessler, Cavanaugh Tocci suggested instituting a resolution process for noise complaints.

The developer proposed a complaint resolution procedure. A written complaint from a resident or business would go first to the developer. Acciona would have five days to respond and if the developer couldn’t fix it, the complaint would be sent to a town designee for investigation.

Any testing would begin within 10 days of the report from Acciona. Test results would go to the plaintiff and town within 30 days. If the town Planning Board agreed the turbine violates permit conditions, the developer would mitigate it. If the plaintiff wasn’t happy with the resolution or it had been longer than 30 days and there had been no resolution, an appeal could be made to the complaint resolution board.

The board will have a member from the developer and the town and an independent consultant agreed upon by the developer and town. That member can change depending on the nature of the complaint.

The board has 30 days to hear the complaint and 30 days to render a binding decision.

Repeated complaints will trigger additional investigations only if the town determines the operational characteristics have changed since the first complaint.

The final statement also proposes eliminating two turbines for noise and wetland concerns, moving a turbine 2.9 miles and adjusting 10 turbines to decrease wind turbulence. It includes additional well, wetland and wildlife studies. Five segments of roads and 23 intersections will need improvements to handle the construction, and 31 of the 51 turbines will be lit with simultaneously flashing beacons, according to Federal Aviation Administration standards.

The statement also responds to all comments made by agencies and the public on the draft and supplemental environmental impact statements.

The statement is available at the Cape Vincent Public Library, 157 N. Real St.; Lyme Free Library, 12165 Main St., Chaumont, and Cape Vincent town clerk’s office, 1964 Route 12E. If it is accepted as complete, it will be available on Acciona’s website as well.

If the board deems the statement complete, it can complete its findings and end the environmental review after 10 days. The board has indicated that could happen Sept. 15. Other involved agencies, but not the public, also will weigh in with findings.