Subd. 1.

Authority and findings.

A.

Statutory authority. This section is adopted pursuant to Minn. Stats. § 473.192.

B.

Findings of fact. The City of Eagan finds that development and redevelopment within certain areas of the city is impacted by aircraft noise; that certain uses of land are inappropriate in areas of high aircraft noise; that some structures do not adequately attenuate aircraft noise resulting in negative impacts on the health, safety and welfare of the residents or inhabitants of the structures; that, through proper construction methods and materials, the means exist to attenuate aircraft noise to interior levels which alleviate such negative impacts; and that the requirements of this section are necessary to promote and preserve the health, safety and welfare of the citizens of Eagan.

Subd. 2.

Purpose. The purpose of this section is to require that certain buildings within the city's aircraft noise zone as identified herein, be constructed with materials and in such a manner that aircraft noise is attenuated by the structure to an interior level which has no adverse impact on the health, safety and general welfare of the residents, in accordance with the Metropolitan Council's guidelines for land use compatibility with aircraft noise. These guidelines are contained in Appendix L of the Metropolitan Council's 2030 Transportation Policy Plan (TPP).

Subd. 3.

Definitions. For purposes of this section, the following terms shall have the meanings given:

Additions: Any extension or expansion of an existing building normally occupied by people.

Aircraft noise zone: Any one of the four zones and buffer zone established from the MSP 2007 Noise Area and identified in the Metropolitan Council Transportation Policy Plan and shown on the official zoning map of the City of Eagan and incorporated herein by reference.

Appurtenance: The visible, functional, or ornamental objects accessory to and part of a building not normally occupied by people including garages and accessory buildings; and other unconditioned spaces including screen porches, gazebos, decks.

Compatible use (COMP): A use that is acoustically acceptable for both indoors and outdoors.

Conditional use (COND): A use that is not permitted, unless it meets the structural performance standards as set forth in Table L-4, and the factors set forth in Table L-5 of the Metropolitan Council 2030 Transportation Plan, Appendix L—Land Use Compatibility Guidelines for Aircraft Noise. The review of COND projects within the buffer zone shall be accomplished by the city; and the Metropolitan Council shall review COND projects located within noise zones 1 through 4. Within these zones, any land use [project] defined as COND under the compatibility guidelines and that is identified by the city as a planned development or requires a different zoning designation will be processed like a comprehensive plan amendment and reviewed under the factors described in Table L-5.

dBA: A unit of sound pressure level weighted by use of the A metering characteristics and weighting as specified in the American National Standards Institute specification for sound level meters (ANSI S1.4-1983), which is hereby incorporated by reference. "dBA" is also referred to as an A-weighted decibel.

Incompatible use (INCO): A use that is not permitted even if acoustical treatment was incorporated in the structure and outside uses restricted.

Infill development: A vacant parcel or parcels of land proposed for development of uses similar to or less noise sensitive than the surrounding developed parcels. (For example, a new house on a vacant lot in a residential neighborhood, or a new industry on a vacant parcel in an established industrial area).

DNL: The day-night average level, or the 24-hour equivalent continuous sound level (time averaged A-weighted sound level) from midnight to midnight, obtained after the addition of ten dBA to sound levels measured from 10:00 p.m. to 7:00 a.m.

Leq: The equivalent continuous sound level which, over the period of one hour, has the same A-weighted sound energy as the time varying sound.

Low-frequency noise: Noise with a frequency of 100 Hz or lower.

New development: A vacant parcel or parcels of land in excess of one acre or requested to be rezoned for development. (For example, a residential subdivision, industrial park or shopping center).

Noise reduction level: The difference between the exterior and interior sound level, expressed in dBA, during the same time period.

Noise buffer zone: As defined by the Metropolitan Council, an area outside the aircraft noise zone, and for MSP, it is defined as a one statute-mile beyond the noise zone 4 (DNL 60-64) contour line. Generally, the noise buffer zone becomes an extension of noise zone 4. To extend noise zone 4 into the buffer zone, the acoustic gradations link needs to be maintained. Thus, for any particular land use in noise zone 4, the corresponding designation for the buffer zone would be the next lowest designation. The purpose of the buffer zone is to provide additional protection for noise sensitive uses within the context of preventive land-use measures, allow for contour expansion/contraction over time, and provide flexibility in using other tools in support of noise efforts (e.g., a TIF district), that may be partially outside the then "current" noise contours.

Provisional use (PROV): A use that is not permitted, unless it meets certain structural performance standards to be acceptable according to MS473.192 (metropolitan area Aircraft Noise Attenuation Act). Structures built after December 1983 shall be acoustically constructed so as to achieve the interior sound levels described in the Structural Performance Standards, Table L-5 of the Metropolitan Council 2030 Transportation Plan, Appendix L—Land Use Compatibility Guidelines for Aircraft Noise.

Recognized acoustical specialist: A person qualified by education and experience to conduct sound level analysis of buildings and approved for such purpose by the city. The approved individual will have at least three years of field experience of sound control and a degree from a recognized institute of higher learning in acoustics or a closely related discipline; or demonstrated expertise in the process of sound analysis of buildings.

Reconstruction of MAC Noise Insulation Program Homes: Replacing or repairing an existing home that received the 5dB package of airport noise home mitigation under the Metropolitan Airports Commission Home Mitigation Program when the replacement of the home is due to a purposeful teardown and total replacement of the home or when the replacement or repair of the home is due to damage to or destruction of the home by storm, fire or other peril.

Redevelopment: A parcel of land with an existing structure or structures which are proposed to be rehabilitated or demolished for different uses. For purposes of the section, this does not apply to individual lots occupied by single-family detached homes, unless the property is subject to previous planned development or subdivision conditions or the property received the 5dB package of airport noise home mitigation under the Metropolitan Airports Commission Home Mitigation Program.

Sound: Energy that is transmitted by pressure waves in the air or in other materials and is the objective cause of the sensation of hearing.

Sound attenuation: The reduction in sound level which occurs between the source and receiver by means of construction methods and materials.

Sound leak: An opening in a structure through which sound can pass.

Sound level: The level of sound pressure measured with a sound level meter and one of its weighting (frequency) networks. When A-weighting is used, the "sound level" is expressed as dBA.

Sound transmission class (STC): A single number rating for describing the degree of sound transmission loss specified for a wall, window, partition or other building element. The higher the STC, the more attenuation the building element will afford. (Ord. 232, 5-19-1987)

Subd. 4.

Scope and effect.

A.

The aircraft noise zones established in this section shall overlay the zoning districts established in chapter 11 of this Code, so that any parcel of land lying in an overlay zone shall also lie on one or more of the established zoning districts. Property within a given overlay zone shall be subject to the requirements established by the other applicable regulations of this chapter and the Code.

B.

Within each aircraft noise overlay zone, all uses shall be permitted in accordance with the regulations for the underlying zoning districts, provided, the appropriate building permit is first obtained and all requirements for conditional and provisional uses under this section are met. No use designated as incompatible (INCO) shall be permitted.

C.

Application of provisions: This section shall apply to all new development, redevelopment, reconstruction of MAC Noise Insulation Program Homes, and construction of a building associated with a new subdivision or planned development, or amended use within an existing planned development. This section shall not apply to additions, remodeling or rehabilitation of an existing residential building, to additions or remodeling of an existing MAC Noise Insulation Program Home, to the construction of an appurtenance to an existing residential building, or to new residential structures constructed on an existing lot (as of the date of this ordinance [from which this section is derived]) where a new subdivision is not created.

Subd. 5.

Issuance of building or occupancy permit. No building or occupancy permit pertaining to land located in an aircraft noise zone will be issued unless the applicant demonstrates compliance with the provisions of this section.

Subd. 6.

Establishment of aircraft noise zones.

A.

Aircraft noise zones established: The following aircraft noise zones are as follows:

B.

Boundaries: The boundaries of the aircraft noise zones are as delineated on the zoning map of the City of Eagan, on file in the office of the city clerk for public use and inspection, and incorporated herein by reference.

Subd. 7.

Noise compatibility regulations.

A.

Noise compatibility tables are adapted from the Metropolitan Council's 2030 Transportation Policy Plan—Appendix L, Land Use Compatibility Guidelines for Aircraft Noise, and as revised in the 2006 Metropolitan Council Builder's Guide—Mitigating Aircraft Noise. Land use compatibility shown in Table 1 hereto establish acceptable uses within each noise zone applicable to the scope of this section.

B.

The noise reduction level requirements, as set forth in Table 2, expressed in dBA, are established for each type of land use, the amount of interior sound level reduction necessary for the use to be compatible in the applicable aircraft noise zone and to meet structural performance standards as set forth in Table L-4 of Appendix L—Land Use Compatibility Guidelines for Aircraft Noise, of the 2030 Metropolitan Council's Transportation Policy Plan.

C.

Any construction requiring a building permit on land located within an aircraft noise zone under the scope of this section shall be constructed in accordance with the requirements set forth in the noise reduction requirements in this section. The necessary reduction will be achieved through the enforcement of provisions in this section and the Builder's Guide. Where a particular structure contains different land uses, the more stringent requirements of the applicable Tables shall apply, except where it is architecturally possible to achieve the appropriate noise reduction level for each different use, and the uses are acoustically separated by a wall or partition with a minimum STC of 25.

Subd. 8.

Implementation and enforcement.

A.

The City of Eagan building inspector is authorized and directed to enforce the provisions of this section.

B.

Plans and specifications:

1.

Required plans and specifications:

a.

All applicants for a building or occupancy permit shall include with the application all plans, specifications or other information required by this section. The plans and specifications shall describe in sufficient detail all pertinent features of the building, building materials, heating and ventilation systems, including, but not limited to, the STC ratings of exterior roof/ceilings, walls, windows, and doors; and other pertinent data as may be requested by the city to indicate conformance with the applicable noise reduction level requirements as specified in the noise compatibility tables. To assure the elimination of sound leaks, the plans and specifications shall demonstrate compliance with the following standards:

(1)

All mechanical ventilation systems shall be installed that will provide the minimum air circulation and fresh air supply requirements as provided in the State and International Building Code for the proposed occupancy without the need to open any exterior doors or windows.

(2)

The perimeter of all exterior windows and door frames shall be sealed airtight to the exterior wall construction.

(3)

Fireplaces shall be equipped with well fitted chimney closing devices.

(4)

All ventilation ducts, except range hoods, connecting interior space to outdoors shall be provided with a bend such that no direct line of sight exists from the exterior to the interior through the vent duct.

(5)

Doors and windows shall be constructed so that they are close fitting. Weather stripping seals shall be incorporated to eliminate all edge gaps.

(6)

All penetrations through exterior walls by pipes, ducts, conduits and the like shall be caulked airtight to the exterior construction.

b.

The city may require that plans and specifications be certified by a recognized acoustical specialist for compliance with this section.

c.

General reduction techniques may be referenced in the Metropolitan Council Builder's Guide.

2.

Approval or denial of permit:

a.

Within 30 days of receipt of appropriate plans and specifications, the city shall approve or reject the plans based upon the ability of the proposed materials and construction techniques to adequately attenuate noise. The city will approve the plans and specifications only if one of the two following requirements (i. or ii.) is met:

i.

The plans and specifications adequately document the use of construction assembly that meet or exceed the STC ratings required by the following table:

* All values—2 STC. The STC laboratory test of construction materials and assemblies must be conducted according to requirements of the American Society of Testing and Materials (ASTM E90 or ASTM E 336); or

ii.

The plans and specifications have been certified by a recognized acoustical specialist as achieving the interior noise level reduction required by the applicable portion of the noise compatibility table.

b.

In the event that the drawings are rejected, the reasons for such rejection will be submitted to the applicant in writing. No construction shall occur prior to the approval of the appropriate plans and specifications. All construction shall be performed in accordance with the approved plans and specifications as determined by the city and shall be deemed to meet the noise attenuation requirements of this section.

C.

Inspections:

1.

All construction or work for which a building permit is required shall be subject to inspections by the city. Inspections of noise attenuation work shall be performed during the required building construction inspections specified by the City of Eagan Building Code.

2.

When inspection indicates that the construction is not in accordance with the approved plans, the city may order such corrective action as may be necessary to meet the noise attenuation requirements of this section. In lieu of performing such corrective action, a building owner may submit a test report based upon field tests showing compliance with the noise reduction level requirements contained in the applicable noise compatibility table. The field test shall be performed in accordance with the "American Society for Testing Materials (ASTM) Standard E 336-84, Part A1.2.2. Outside to Inside (Level Reduction)."

(Ord. No. 436, 2nd series, § 1, eff. 2-3-09; Ord. No. 465, 2nd series, § 1, 11-16-2010)