12-101.1 Purpose and intent. The purpose of this section is to establish development standards for environmentally sensitive land areas, in a manner that provides for reasonable use of land while retaining to the maximum extent possible environmentally sensitive portions in a predeveloped state. These provisions are predicated on the concept that land use policy decisions are made in the context of land characteristics. Optimally, these characteristics include all physical as well as locational characteristics of a development site. The requirements and standards of this section are intended to promote low-impact development of identified environmentally sensitive areas by the use of incentives aimed at minimizing environmental disturbance.

12-101.2 Applicability. The provisions of this section are applicable to the following environmentally sensitive lands:

1.

Steep hillsides. The hillside development standards apply to predevelopment conditions for new development on steep slopes.

2.

Special flood hazard areas. The floodplain development standards apply to predevelopment conditions for new development within "areas of special flood hazard" identified in article VIII of this ordinance.

3.

Problem soil areas. The problem soils development standards apply to predevelopment conditions for new development located within the listed soil types as identified in the Wilson County Soil Survey (USDA, Soil Conservation Service). The groundwater protection standards developed herein shall apply to any lot not served by public water and/or sewer.

4.

Exemptions. The provisions of this section shall not apply to the following:

a.

Any construction, development or use initiated pursuant to any valid building permit or approved final site development plan issued or approved prior to adoption of this ordinance.

b.

Any essential public utility facility, system or roadway initiated to provide utility services or access to a property.

c.

Repair or replacement to an existing structure or building that does not increase the impervious surface area of the site more than 25 percent.

d.

Construction of a single-family or duplex dwelling on a lot which was platted and recorded at the time of adoption of this ordinance.

12-101.3 Variable lot size option. Within development sites that contain steep slopes, areas subject to flooding or problem soils the clustering of residential lots on portions of a development site that are not subject to such problems is strongly encouraged. Within such developments, the provisions of article V, subsection 5-104.3, Variable lot residential development, shall apply. Portions of the development site within variable lot size developments that contain slopes of 20 percent or greater, are subject to flooding or are identified as wetlands shall be retained as open space.

(Ord. of 10-23-2009, § 12-101)

12-102.1 Residential sites. Residential development on property that includes slopes of 18 percent or greater shall minimize changes to grade, cleared area, and volume of cut and fill on the site and shall be subject to the following standards:

1.

Single- and two-family dwellings.

a.

Site plan required. Any lot two acres or less in size that is created for use as a building site for a single- or two-family dwelling shall be considered a critical lot. Approval of a site plan prepared by a registered engineer containing the information required by subsection 4-102.103, Lots located on steep slopes, of the subdivision regulations shall be required.

b.

Minimum lot size. Within areas of steep slopes the following minimum lot size provisions shall apply:

2.

Multifamily development density reductions. In all multifamily (RM) zone districts manipulation of natural slopes shall result in the following reductions in density permitted for those portions disturbed:

12-102.2 Nonresidential sites.

1.

Reductions in allowable impervious surface ratio (ISR). In all nonresidential districts, manipulation of natural slopes shall result in the following reductions in allowable impervious surface ratio (ISR) for those portions disturbed:

2.

Grading standards for hillside sites in nonresidential zone districts. Grading standards for hillside sites in nonresidential zone districts shall be as follows:

a.

Minimal disruptions. For lots or parcels containing natural slopes of 20 percent or greater, approval of a site development plan shall be based upon a demonstration that the development plan minimizes disturbance to these slopes. Architectural and engineering features that reduce unnecessary encroachment on steep slopes may include, but are not limited to, use of retaining walls and structural foundations to return to natural grade.

b.

Slope stabilization. Finished slopes shall be stabilized by perennial vegetative cover. Slope face stabilization by use of rip-rap or hydraulically applied concrete is prohibited.

(Ord. of 10-23-2009, § 12-102)

12-103.1 Filling permitted.

1.

Filling of land located outside the regulatory floodway. Filling of land situated within the portion of the floodplain which lies outside the "regulatory floodway" (as defined by this ordinance) is permitted subject to the following provisions:

a.

All filling shall comply with all provisions contained in article VIII, section 8-301, Floodplain district regulations.

b.

No filling shall be permitted without a detailed plan prepared and sealed by a licensed engineer and approved by the City Engineer.

c.

Any plan for placing fill material shall demonstrate that the amount of fill material being located within an area of special flood hazard is less than or equal to material being removed from such area.

d.

No encroachments, including fill material, new construction, substantial improvements or other developments shall be located within an area of special flood hazard, unless certification by a registered professional engineer is provided demonstrating that the cumulative effect of the proposed encroachments or new development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than 0.1-foot during the occurrence of the base flood discharge at any point within the community. The engineering certification shall be supported by technical data that conforms to standard hydraulic engineering principles.

e.

Where fill material is used such material shall sufficient to raise the site to an elevation at least equal to the height of the regulatory flood.

2.

Status of filled sites. Any site which is filled in accordance with the provisions of subpart 1 of this section shall be subject to all provisions of article VIII, unless and until such site is formally removed from the area of special flood hazard by action of the Federal Emergency Management Agency. Any such site which is formally removed from the area of special flood hazard by action of the Federal Emergency Management Agency shall following the date of such action no longer be subject to the provisions of article VIII, section 8-301, Floodplain district regulations.

12-103.2 Status of other sites. Any site located within an area of special flood hazard, other than sites which have been filled as provided in subsection 12-103.1, may be developed only in full compliance with the provisions of article VIII, section 8-301, Floodplain district regulations.

(Ord. of 10-23-2009, § 12-103)

12-104.1 Purpose and intent. It is the purpose of this section to provide appropriate standards relating to the operation of certain activities throughout the City. Such operations may create or maintain such excessive noise, vibration, air pollution, odor, or electromagnetic interference as to be a detriment to the public health, comfort, convenience, safety and welfare. These standards are therefore provided to protect the public interest and promote the public health and welfare.

12-104.2 Applicability.

1.

In all districts every building or other structure or tract of land that is established, developed or constructed shall comply with each and every performance standard contained in this section, as applicable.

2.

When the use or building or other structure is extended, enlarged or reconstructed after the effective date of this zoning ordinance, the applicable performance standards shall apply with respect to such extended, enlarged, or reconstructed portion or portions of such use or building or other structure.

3.

In the case of any conflict between the activity type and the performance standards, the latter shall control.

4.

The provisions of this section shall apply notwithstanding the issuance after the effective date of this ordinance of any zoning permit or certification of zoning compliance.

5.

In case of conflict between the performance standards set forth herein and any rules or regulations adopted by any other governmental agencies, the more restrictive shall apply.

12-104.3 General exemptions. The following activities or sources are exempt from these regulations:

1.

Temporary construction, excavation and grading.

2.

Demolition activities which are necessary and incidental to the development of facilities on the same lot, on another of several lots being developed at the same time, or on the public right-of-way or easement for a community facility activity.

3.

Aircraft, railway and operating motor vehicles.

(Ord. of 10-23-2009, § 12-104)

12-105.1 Noise.

1.

Applicability. These standards apply to noise from any machinery or equipment that is part of or operated within any development provided for in this ordinance, including continuous and intermittent noise, noise emitted by speaker boxes and any other commercial or industrial activities which are under the control of the occupant of a building site.

2.

Method of measurement. Noise shall be measured with a sound level meter which meet the standards pertinent for type 52A, meters of the American National Standards Institute specifications for sound level meters. Noise levels shall be measured using an A-weighted sound pressure level scale. Impact noises, produced when two or more objects strike each other, shall be measured using the fast response of the sound level meter and other noises using the slow response. For purposes of this ordinance, impact noises shall be considered to be those noises whose peak values are more than three decibels higher than the values indicated on the sound level meter.

3.

Required performance level. The maximum permitted sound pressure levels in decibels across lot lines and district boundaries shall be in accordance with the following table. The [following] table shall be used to determine the maximum noise level, measured in A-weighted decibels, which shall be permitted at the property line of the closest use in each of the following categories:

12-105.2 Vibration.

1.

Applicability. These standards are to apply to the operation of any device that creates a vibration above the vibration threshold (see subpart 2, below) at or beyond the property boundary of the source if on private property or at 150 feet from the source if on public space or public right-of-way. These standards do not apply to blasting operations which are conducted in connection with construction activities. Blasting operations shall be controlled as provided in appropriate sections of the Tennessee Code and any locally adopted ordinances or regulations.

2.

Method of measurement. Vibration displacement shall be measured with an instrument capable of simultaneously measuring in three mutually perpendicular directions. Measurements shall be made at or beyond the adjacent lot line or the nearest residential district boundary line as described herein. The maximum permitted displacements shall be determined by the following formula:

3.

Required performance level. No activity or operation shall cause vibrations in excess of the maximum displacement permitted at the points described below for the district indicated. The maximum permissible displacement shall be determined by the use of the formula presented in subpart 2 of this section and the appropriate K constant, shown in the [following] tables:

12-105.3 Smoke and particulate matter. Any land use or other activity which involves the emission of smoke, particulate matter, or other air pollutants shall comply with all applicable standards set forth in state and federal statutes and regulations regarding the emission of air pollutants. Any such land use or other activity shall also obtain and maintain all necessary licenses and permits from the appropriate state and federal agencies, such as the United States Environmental Protection Agency.

12-105.4 Odor.

1.

Applicability. Any use established in an industrial district shall be so operated as to comply with the performance standards governing noxious odorous materials set forth, hereinafter, for the district in which such use is located. No use already established on the effective date of this ordinance shall be so altered or modified as to conflict with, or further conflict with the provisions of this section. In addition, to the performance standards specified hereinafter, the emission of noxious odorous matter in such a manner or quantity as to be detrimental to or endanger the public health, safety, comfort or welfare is hereby declared to be a public nuisance and shall henceforth be unlawful.

2.

Required performance level.

a.

Standards applicable within I-R districts and at any boundary of a residential district. Within any I-R district and along any boundary separating any industrial district from any residential district, the emission of noxious odorous matter in such quantities as to be detectable at any point along lot lines when diluted in the ratio of one volume of noxious odorous air to four or more volumes of clean air is prohibited.

b.

Standards applicable within I-G and I-S districts. Within any I-G or I-S district, except along any residential district boundary where the provisions of subpart a, above, shall apply, the emission of noxious odorous matter in such quantities as to be detectable at any point along lot lines when diluted in the ratio of one volume of noxious odorous air to eight or more volumes of clean air is prohibited.

12-105.5 Toxic, hazardous and radioactive matter.

1.

Applicability. The provisions of this section shall apply to all uses and activities located within any zoning district.

2.

Continuous compliance with federal, state and local laws and regulations required. Any land use or activity which involves the use of toxic, hazardous, or radioactive materials shall comply at all times with all applicable standards set forth in local, state and federal statutes and regulations regarding the use, storage, transportation, emission and disposal of such materials. Any such land use or other activity shall also obtain and maintain all necessary licenses from the appropriate state and federal agencies, such as the United States Environmental Protection Agency.

3.

Required performance level. In all zoning districts inclusive, no use shall for any period of time discharge across the boundaries of the lot where it is located toxic matter in such concentrations as to be detrimental to or endanger the public, safety, comfort or welfare, or cause injury or damage to property or business.

12-105.6 Glare.

1.

Applicability. The standards contained within this section shall apply in all commercial and industrial districts and to all community facilities activities located within any district.

2.

Required performance level.

a.

All site lighting shall be shielded so that substantially all directly emitted light falls within the property line. No illumination in excess of one-half footcandle shall be permitted within the boundaries of any adjacent residentially developed property. A footcandle is the illumination at all points one foot distance from a uniform point source of one candlepower.

b.

All exterior building floodlights shall be shielded so that all of the light falls upon either the surface of the structure or on the ground.

c.

No illumination shall produce direct, incident, or reflected light that interferes with the safe movement of motor vehicles on public streets. Lighting prohibited by this provision shall include, but not be limited to:

i.

Any light that may be confused with or construed as a traffic control device;

ii.

Any animated, flashing or changing intensity lights, except for temporary holiday displays.

12-105.7 Fire and explosive hazards.

1.

Applicability. The standards contained within this section shall apply in all commercial and industrial districts and to all community facility activities located within any district.

2.

Required performance level.

a.

All flammable solid, liquid and gaseous substances shall be stored and used in accordance with all applicable federal, state and local statutes and regulations.

b.

In all nonresidential zoning districts, the storage or use of solid materials or products ranging from incombustible to moderate burning is permitted.

c.

In all nonresidential zoning districts, the storage or use of solid materials or products ranging from free or active burning to intense burning is permitted, provided that either of the following conditions is met. Free or active burning to intense burning is a rate of combustion described by material that burns with a high degree of activity and is consumed rapidly. Examples include sawdust, powdered magnesium, pyroxylin and other solids deemed by the fire marshal to have equivalent burning characteristics.

i.

Solid materials or products shall be stored or used within completely enclosed buildings having no less than two-hour fire resistant exterior walls and protected with an automatic fire extinguishing system; or

ii.

Said material, if stored outdoors, shall be no less than 50 feet from the nearest lot line.

d.

Storage tanks for flammable liquids and gasses shall be located no closer than 50 feet to any lot line.

12-105.8 Electromagnetic interference. In all districts, no use, activity or process shall be conducted which produces electromagnetic interference with radio and television reception on a property beyond the lot line on which such activity exists.

12-105.9 Nonconforming by reason of operational performance standards. Any use existing on the effective date of this ordinance, or subsequent amendment as applicable and permitted by right that does not meet the requirements of one or more of the operational performance standards established explicitly in this section or by reference shall be subject to the provisions of article XIII, subsection 13-102.11, Special provisions pertaining to uses not conforming to performance standards.

(Ord. of 10-23-2009, § 12-105)