Rand: Critique of Noise Impact Report for NextEra's Golden West Wind Energy Center

NextEra's Golden West Wind Energy Center sited in El Paso County, Colorado was required under the County permit to conduct a noise impact study after the project was placed in service in October 2015. Acoustician Robert Rand was asked by residents living near the turbines to review the noise impact study as prepared by NextEra consultant, Epsilon Associates. Mr. Rand's report, included here, identified several material errors with Epsilon's report and also found that the project appears to be operating outside the noise limits permitted by the County and the State. The Golden West Wind Energy Center consists 145 1.72-megawatt GE turbines for a total installed capacity of 249.4-megawatts Mr. Rand's executive summary is provided below. The full report can be accessed by clicking the document icon on this page. 

El Paso Board of County Commissioners
200 South Cascade Avenue, Suite 100
Colorado Springs, CO 80903-2202

Re: Review of Epsilon Report 4177 October 7, 2016
Golden West Wind Energy Center El Paso County, Colorado

Per request of neighbors in Calhan, Colorado, I respectfully submit this review of the Sound Level Compliance Evaluation Report for the Golden West Wind Energy Center El Paso County, Colorado prepared by Epsilon Associates, Inc. for NextEra Resources, LLC dated October 7, 2016. I found errors and omissions. Professional opinions are provided below. 

1. The report does not fulfill the requirements of Resolution No. 15-55 Section 17. Section 17 required "an additional noise impact study, which shall evaluate the actual noise impacts of the project during operation". The Epsilon Report ignores complaints of noise disturbance registered with the County and/or facility, and omits noise level and character assessments against relevant noise criteria [1].

2. The Epsilon Report disregards Colorado State Statute ARTICLE 12 – NOISE ABATEMENT, C.R.S. Sections 25-12-101 to -110, "Noise in excess of the limits provided in this article [note: 45 dBA at night for periodic noise] constitutes a public nuisance."

3. The Epsilon Report does not assess for noise disturbance despite apparent neighbor complaints of noise disturbance. Noise disturbance is prohibited by the County Ordinance No. 02-1, Section 3(e) and Section 4(a).

4. The Epsilon Report’s data confirm the presence of intrusive facility noise levels exceeding the Colorado Statute Article 12, 45 dBA noise limit for periodic noise, establishing periodic noise levels a public nuisance at some 23 non-participating properties with dwellings.

5. The Epsilon Report provides prima facie evidence that the Golden West Facility wind turbine noise is a public nuisance under State law[2] yet neglects to inform the reader. 

6. The Report does not corroborate that all turbines were operating at full power/acoustic output. Experience at other facilities has shown some turbines operated at lower output during testing which can reduce total noise levels at a measurement location. The Report as submitted does not represent worst case conditions. 

7. The Epsilon Report attests no non-participating property "will be exposed to sound levels over 50 dBA". This is contradicted by the Report's data exceeding 50 dBA some portion of the time at several non-participating property line locations. Example, the L10 noise level, exceeded 10 percent of the time, may equate to 36 days per year above regulatory limits.

8. Location 7 appears farther away from the nearest Turbine #55 (710 ft) than the nearest non-participating property line (~480 ft based on scaled Epsilon figure). The distance to the Location 7 assures noise levels from Turbine #55 are under-represented by 3 dB.

9. The Epsilon Report removes unattended averaged data over 50 dBA with a dismissive attribute for contamination from non-turbine noise sources. Not a valid assumption without witnessing, observers, recordings, hence no basis to consign to non-turbine noise sources.

10. Noise levels of 40 dBA and higher, per ANSI S12.9 Part 5, are incompatible with rural land use [Epsilon knowledge, footnote 3]. Noise impact assessment absent in Epsilon Report. 

11. Noise levels of 40 dBA at night exceed WHO 2009 thresholds of noise effects on people [Epsilon knowledge, footnote 4], assuring sleep disturbance. Noise impact assessment was not found in the Epsilon Report. Epsilon omitted assessment of Golden West noise impacts on children, chronically ill and elderly.

12. Even wind industry consultants documented, noise levels over 40-45 dBA are associated with complaints such as sleep disturbance [5]. However, the Epsilon Report was mute. 

Summary of review: 

Contrary to the permitting requirement, the Epsilon Report neglected to assess noise impacts. County, State, and professional noise impact criteria were omitted. 

The Epsilon Report substantiates that the Golden West facility noise exceeds predicted noise levels, and exceeds County and State noise limits, while not confirming maximum output for all turbines during testing (noise levels may go higher than Epsilon measured). The Epsilon Report should not be considered protective of public safety, health and welfare, and departs from accepted professional practice. 

Epsilon's noise measurements clearly confirm why neighbors complain. 

Experience has shown that when there are noise complaints during normal operation, this reveals that the designers, consultants and regulators have failed to meet their public protection responsibilities.

The Epsilon Report ignores law and does not assess complaints or impacts. Who benefits? 

My professional experience says this facility should not have been permitted with turbines this large and this close to non-participating residential properties. The Epsilon Report shows the noise levels do not always comply with law and are consistent with noise disturbance. The law, were it to be enforced, requires the facility noise levels to be reduced. 

Thank you for your consideration of this review letter. If you have any questions, please contact me.

Respectfully submitted,

Rand Review Epsilon 4177 Golden West 170321

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MAR 23 2017
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