The Roanoke County Board of Supervisors has adopted a wind energy policy that sits on the least-protective edges of current siting standards: a 60dB sound limit, and setbacks of 1000 feet from homes. Four of the five supervisors supported the proposal, saying it would protect residents; the 60dB limit was said to be comparable to sound along US 460, a four-lane federal highway in the area.

A fifth board member, representing the district where the only current wind farm proposal is sited, encouraged the board to hold off on setting absolute limits; Ed Elswick said the county should wait until it has a proposal and hire experts to weigh in “rather than grabbing numbers out of the air.” That didn’t stop him from tossing a number in the hat: he proposed that sound be limited to levels typical of rural areas, suggesting 30dB at the nearest property line.

UPDATE, 10/12/11: Elswick has asked the board to reconsider the 60dB limit; it will be on the agenda at a meeting in late October. Two board members said they knew they wouldn’t change their votes; one said he wanted to hear further discussion, and the fifth board member was not present when Elswick raised the issue again. And, 26 local residents have sued the Board of Supervisors, saying that the sudden shift from a 2600-foot setback proposal to the 1000-foot decision lacked proper notice of a public hearing, and was “clearly unreasonable, arbitrary or capricious.” UPDATE, 10/26/11: The Board of Supervisors voted to not reconsider their previous decision.

The area where 15-18 turbines are currently proposed is a section of hills about ten miles from Roanoke, a near-to-town rural enclave that has federal highways two to four miles in two directions, along with I-81 a few miles distant (see 2 mile scale at lower left, above). It appears that no existing ambient levels have been determined there, though it would not be surprising if some of the highways are faintly audible at the site.  There may well be homes in valleys, however, where current soundscape conditions are notably free of road noise, and which will now face next-to-the-highway noise levels from turbines on ridges nearby.

It is unclear at this point how many homes are close to the 1000-foot setback distance; these will be the places where the soundscape is likely to be most dramatically changed. A half-mile setback was proposed in a previous draft of the policy; this would have likely minimized the likelihood of major impacts on neighbors, though it may not have eliminated noise issues entirely. In areas such as this, it’s often hard to site wind farms without fairly relaxed noise and setback limits.  Here, as in many other towns and counties, board members apparently felt that it was more important to not exclude wind development than it was to maintain current soundscape conditions in this rural enclave.