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Minnesota - “Noise” Setbacks to Wind Turbines

As a layperson researching what Minnesota calls a: "Wind Energy Conversion System" (WECS) or also known as a Wind Turbine, there is one issue that always rears its ugly head, "Noise". I found that Minnesota is one of the many states to specify maximum exposure levels of noise to its citizens. The Minnesota Rules Chapter 7030 describes the limiting levels of sound established on the basis of present knowledge for the preservation of public health and welfare. Within this article I will attempt to provide a logical trace of the sound limiting requirements, along with some possible "delta" areas at the County Zoning Ordinance Levels with regards to a WECS application.

As a layperson researching what Minnesota calls a: "Wind Energy Conversion System" (WECS) or also known as a Wind Turbine, there is one issue that always rears its ugly head, "Noise". I found that Minnesota is one of the many states to specify maximum exposure levels of noise to its citizens. The Minnesota Rules Chapter 7030 describes the limiting levels of sound established on the basis of present knowledge for the preservation of public health and welfare. Within this article I will attempt to provide a logical trace of the sound limiting requirements, along with some possible "delta" areas at the County Zoning Ordinance Levels with regards to a WECS application.

MN Rule 7030 http://www.revisor.leg.state.mn.us/arule/7030/

There are two critical questions that need to be asked before a person can determine how this rule applies to them:

1. What is the Land Use Activity at the location of the receiver (person)?
2. At what location is Human Activity nearest to the noise source?

MN Rule 7030.005 contains a listing of common day-to-day Land Use Activities. Simply go to the table and find the best description of the Land Use Activity that supports your situation. Associated with each Land Use Activity is a state assigned Noise Area Classifications or NAC. Remember, the NAC is predicated on the Land Use Activity, I recommend this be further substantiated through... [truncated due to possible copyright]  

As a layperson researching what Minnesota calls a: "Wind Energy Conversion System" (WECS) or also known as a Wind Turbine, there is one issue that always rears its ugly head, "Noise". I found that Minnesota is one of the many states to specify maximum exposure levels of noise to its citizens. The Minnesota Rules Chapter 7030 describes the limiting levels of sound established on the basis of present knowledge for the preservation of public health and welfare. Within this article I will attempt to provide a logical trace of the sound limiting requirements, along with some possible "delta" areas at the County Zoning Ordinance Levels with regards to a WECS application.

MN Rule 7030 http://www.revisor.leg.state.mn.us/arule/7030/

There are two critical questions that need to be asked before a person can determine how this rule applies to them:

1. What is the Land Use Activity at the location of the receiver (person)?
2. At what location is Human Activity nearest to the noise source?

MN Rule 7030.005 contains a listing of common day-to-day Land Use Activities. Simply go to the table and find the best description of the Land Use Activity that supports your situation. Associated with each Land Use Activity is a state assigned Noise Area Classifications or NAC. Remember, the NAC is predicated on the Land Use Activity, I recommend this be further substantiated through Property Tax records, etc., if questions should arise about the land classification.

MN Rule 7030.0060 identifies where sound measurements will be taken, it states; "Measurement of sound must be made at or within the applicable NAC at the point of human activity which is nearest to the noise source. All measurements shall be made outdoors." This section within MN Rule 7030 is critical because it makes a clear statement, Sound Measurements must be made "at" or "within" NAC and does not restrict or specify, in any fashion, measurements to be made only at a specific location, i.e., Household Unit. Lastly, human activity would include areas where there are obvious signs of outdoor activity indicating areas used for living space (pools, playsets, patios, gardens, etc).

MN Model Wind Ordinance vs MN Rule 7030

In 2005, there were two important state sponsored documents released:

1) The Minnesota Model Wind Ordinance - 2005
http://www.cleanenergyresourceteams.org/pdf/Model%20Wind%20Ordinance%20w%20explanation.pdf

2) The Companion Document to the Minnesota Model Wind Ordinance - 2005
http://www.cleanenergyresourceteams.org/pdf/FINAL%20WIND%20ORD%20COMP%20DOC.pdf


Both documents are available on the internet via the embedded links. The MN Model Wind Ordinance is simply a listing of black & white requirements and the Companion Document provides the reader insight and explanation as to how the governing group derived those black & white requirements.

I will provide an overview of two excerpts addressing "Noise" as found in the Companion Document to the Minnesota Model Wind Ordinance. I believe these excerpts as interpreted within that document may have consequences during implemented at local Zoning Ordinances levels.

Excerpt # 1 - Page 13; "The noise standard established in Minnesota rules for a residence is 50 decibels at night."

The excerpt above is in conflict with MN Rules 7030.00040 subpart 2. The use of "residence" is not contained within any NAC, the proper statement should have made reference to NAC #1 and not a "residence". The statement of "50 decibels at night" is also incorrect for a NAC # 1, the rules states it cannot exceed 50dB more than 50% of the time during nighttime hours.

Excerpt # 2 - Page 17; "Noise impacts are mitigated with distance. Examination of several Environmental Quality Board wind energy conversion system site permit dockets shows that a 750 foot setback from residents is generally adequate to address noise issues, based on compliance with Minnesota Pollution Control Agency noise standards outlined in Minnesota Rules 7030."

The excerpt above with the reference to "residents" is in conflict to MN Rule 7030.00060; "Measurement of sound must be made at or within the applicable NAC at the point of human activity which is nearest to the noise source. All measurements shall be made outdoors." The use of the word "residents" implies a measurement restriction to the outside of a structural location.

The "fixed" 750 foot for a "House" appears in the Minnesota Model Wind Ordinance of 2005, Section 3A- Commercial WECS, subsection (i) Setback to "Homes", again a fixed distance in conflict to MN Rule 7030.0060.

In closing, MN Rules Chapter 7030 was designed to protect citizens from "Noise" levels that exceed the stated levels based on the NAC. The standards within MN Rules 7030 are consistent with speech, sleep, annoyance, and hearing conservation requirements for receivers (people) within areas grouped according to land activities by the Noise Area Classification.

If you suspect your local Zoning Ordinance does not support MN Rules 7030, refer the Zoning Board to the following:

MN Rules 7030.0030 - No person may violate the standards established in part 7030.0040, unless exempted by Minnesota Statutes, section 116.07, subdivision 2a. Any municipality having authority to regulate land use shall take all reasonable measures within its jurisdiction to prevent the establishment of land use activities listed in noise area classification (NAC) 1, 2, or 3 in any location where the standards established in part 7030.0040 will be violated immediately upon establishment of the land use.



Source: link missing! please notify us

MAR 29 2007
http://www.windaction.org/posts/8037-minnesota-noise-setbacks-to-wind-turbines
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