The following performance standards apply to all industrial uses permitted within an LI Limited Industrial zoning district:
1. Physical Appearance. All operations shall be carried on within an enclosed building except that new materials or equipment in operable condition may be stored outside. Normal daily inorganic wastes may be stored outside in containers, provided that such containers are not visible from the street.
2. Fire Hazard. No operation shall involve the use of highly flammable gases, acid, liquids, or other inherent fire hazards. This prohibition shall not apply to the normal use of heating or motor fuels and welding gases when handled in accordance with the regulations of Polk County and the City of Windsor Heights.
3. Maximum Permitted Sound Levels Adjacent to Residential Zoning Districts. No operation in the LI District shall generate sound levels in excess of those specified in Table 171.07-1 at the boundary of a residential district. All noises shall be muffled so as not to be objectionable because of intermittence, beat frequency, or shrillness.
4. Sewage and Wastes. No operation shall discharge into a sewer, drainage way, or the ground any material which is radioactive, poisonous, detrimental to normal sewer plant operation, or corrosive to sewer pipes and installations.
5. Air Contaminants. No material may be discharged into the air from any source in such quantity as to cause injury, detriment, nuisance, or annoyance to any considerable number of people or to the public in general; or to endanger the health, comfort, or safety of any considerable number of people or to the public in general; or to damage other businesses, vegetation, or property.
6. Odor. The emission of odors determined by the Planning and Zoning Commission to be obnoxious to most people shall be prohibited. Such odors shall be measured at the property line of the operation.
7. Gases. No release of noxious or poisonous gases shall be permitted except as provided in this section. Measurements of sulfur dioxide, hydrogen sulfide, or carbon monoxide shall not exceed 5 parts per million taken at the property line of the operation.
8. Vibration. All machines shall be mounted to minimize vibration. No measurable vibration shall occur at the property line of the operation which exceeds a displacement of 0.003 inch.
9. Glare and Heat. All glare generated by a use shall be shielded or directed so as not to be visible at the property line of the operation. No heat may be generated from an operation that raises the air temperature at the property line of the operation by more than five degrees Fahrenheit above the ambient air temperature.
10. Storage of Chemical Products. If allowed by special use permit, any above or below ground storage of liquid petroleum products or chemicals of a flammable or noxious nature shall not exceed 150,000 gallons when stored on one lot less than one acre. Such storage shall not exceed 25,000 gallons in any one tank. Storage of liquid petroleum products or chemicals of a flammable or noxious nature in excess of 25,000 gallons shall be located at least 50 feet from any structure intended for human habitation and at least 200 feet from any Residential, Office, or Commercial zoning district.