It is the intent of the performance standards to set minimum criteria for all uses of property in order to protect the health, safety and general welfare of the residents of the City and to protect the natural and manmade environments from degradation.
1. Application of Standards. Any use established after the effective date of this chapter shall fully comply with the performance standards. Existing uses which are not in compliance with the performance standards contained in this chapter upon its adoption are exempt to the extent they must comply within five years from the date of adoption of this chapter. Conditions which do not comply shall not increase in scope or magnitude.
2. Glare. Glare of light from any operation and all lighting for parking areas or for the external illumination of buildings or grounds shall be directed in a manner such that direct or indirect illumination from the source of light shall not exceed one and one half foot-candles at property lines in residential zoning districts.
3. Heat. No continuous, frequent or repetitive discharge or emission of heat shall be allowed if it increases the ambient air or water temperature by one degree centigrade or more beyond the property line.
4. Odor. The emission of offensive odorous matter from any use shall not exceed the odor threshold concentration defined in the American Society for Testing and Materials Method D1391-57 Standard Method for Measurement of Odor in Atmosphere (Dilution Method) as the level which will just evoke a response in the human olfactory system where measured as set forth below:
A. In all non-industrial zoning districts, when measured beyond lot lines at ground level or habitable elevation, odorous matter shall not exceed the odor threshold concentration.
B. In all industrial zoning districts, when measured beyond zoning district lines at ground level or habitable elevation, odorous matter shall not exceed the odor threshold concentration.
5. Particulates. No solid or liquid particles shall be emitted at any point in concentrations to exceed those set by the State of Iowa.
6. Smoke. The emission of smoke from any operation or activity shall not exceed a density or equivalent opacity permitted below. For the purposes of grading the density or equivalent opacity of smoke, the Ringelmann Chart as published by the United State Bureau of Mines shall be used.
A. In all non-industrial zoning districts, the emission beyond lot lines of smoke darker in shade than Ringelmann No. 1 from any chimney, stack, vent, opening or combustion process is prohibited.
B. In industrial zoning districts, the emission beyond lot lines of smoke darker in shade than Ringelmann No. 2 from any chimney, stack, vent, opening or combustion process is prohibited; except that the emission of smoke of a shade not to exceed Ringelmann No. 3 is permitted for not more than three minutes total in any one eight-hour period when starting or cleaning a fire.
7. Toxic Matter. The release of airborne toxic matter from any use or activity shall not exceed the fractional quantities permitted below the Threshold Limit Values adopted by the American Conference of Government Industrial Hygienists. If a toxic substance is not listed, verification that the proposed level of toxic matter will be safe and not detrimental to the public health or injurious to plant and animal life will be required. The measurement of toxic matter shall be on the average of any 24-hour sampling period. The release beyond lot lines in all zoning districts shall not exceed one-eighth of the Threshold Limit Values.
8. Vibration. Earth-borne vibrations from any operation or activity shall not exceed the displacement values below at the property line in non-industrial districts and at the industrial zoning district line in industrial zoning districts. Vibration displacement shall be measured with an instrument capable of simultaneously measuring in three mutually perpendicular directions. The maximum vector resultant shall be less than the vibration displacement permitted. The maximum permitted displacements shall be determined by the formula, D=K/f; where D equals displacement in inches; K equals the constant given below and f equals the frequency of the vibration transmitted through the ground in cycles per second.
Continuous | Impulsive* | Less than 8 Pulses per 24-hour Period | |
Non-Industrial Zoning Districts | .003 | .006 | .015 |
Industrial Zoning Districts | .030 | .060 | .15 |
* Impulsive - at least one second rest between pulses which do not exceed one-second duration. | |||
9. Aeration Windmills. The following performance standards are required when constructing an aeration windmill as allowed in this chapter:
A. Permit Required. Each applicant for the construction of an Aeration Windmill shall obtain a Building Permit on forms provided by the Building Department.
B. Height Restriction. The maximum height of an Aeration Windmill measured from bottom of the structure is 25 feet.
C. Setback Requirement. The Aeration Windmill must be setback at least five feet greater than the height of the windmill from any residential structure.
D. Fencing. Each Aeration Windmill shall be surrounding by a fence of at least 48 inches in height.
E. Mounting. The Aeration Windmill structure shall be permanently mounted to the ground and shall not be mounted on a portable or movable structure.
F. Stability. A permitted Aeration Windmill structure shall be designed and installed so as to withstand a wind force of 90 miles per hour.
G. Grounding. Every permitted Aeration Windmill shall be properly connected to a grounding rod, being a metal pole permanently positioned in the ground to serve as an electric conductor through which electrical current may safely pass and dissipate.
H. There shall be no more than one Aeration Windmill per pond.
(Ord. 2014-1020 – Dec. 14 Supp.)