17.24.060   Restrictions and requirements.
   All structures, land and uses in the industrial district (I) shall be in compliance with the following restrictions and requirements:
   A.   Minimum Lot Requirements. The minimum lot area shall be ten thousand (10,000) square feet. The minimum lot width shall be eighty (80) feet.
   B.   Minimum Yard Requirements. There shall be a front yard of not less than a depth of twenty-five (25) feet. There shall be a rear yard of not less than a depth of twenty (20) feet. Each side yard shall be not less than ten (10) feet; provided, that on lots adjacent to a residential district all buildings shall be located so as to provide a minimum side and rear yard of twenty-five (25) feet along that portion of the lot adjacent to the residential district.
   C.   Maximum Height. The height of all buildings and structures shall not exceed seventy-five (75) feet.
   D.   Performance Standards. To be a permitted industrial use or as a permitted conditional use, such use must meet the following performance standards:
   1.   Air Quality. Air quality must comply with South Dakota laws and regulations.
   2.   Hazardous Materials. The storage and use of liquid petroleum products, chemicals and gases of a flammable or noxious nature must comply with all local and state fire codes and regulations.
   3.   Gases. All noxious gases shall be controlled to the extent that they will not be injurious to life and property. The gases sulphur dioxide and hydrogen sulphide shall not exceed five parts per million, carbon monoxide shall not exceed twenty-five (25) parts per million and nitrous fumes shall not exceed five parts per million. All measurements shall be made at the property line.
   4.   Glare and Heat. All glare, such as welding arcs and open furnaces, shall be shielded so that they will not be visible from the property line. No heat from furnaces or processing equipment shall be sensed at the property line to the extent of raising the temperature of air or materials more than five degrees F.
   5.   Noise. No operation shall be carried on which involves noise in excess of the normal traffic noise of the adjacent street at the time of the daily peak hour of traffic volume. Noise shall be measured at the property line and when the level of such noise cannot be determined by observation with the natural senses, a suitable instrument may be used and measurement may include breakdowns into a reasonable number of frequency ranges. All noises shall be muffled so as not to be objectionable due to intermittence, beat frequency or shrillness.
   6.   Physical appearance. All operations shall be carried on within an enclosed building except that new materials or equipment in operable condition may be stored in the open. Normal daily waste of an organic nature may be stored in containers not in a building when such containers are not readily visible from the street.
   7.   Sewage and Liquid Wastes. No operation shall be carried on which involves the discharge into a sewer, watercourse, or the ground of liquid wastes of any radioactive nature, or liquid wastes of a chemical nature which are detrimental to normal sewage plant operation or corrosive and damaging to sewer pipes and installations.
   8.   Vibration. All machines including punch presses and stamping machines shall be mounted so as to minimize vibration. Vibration shall not be so excessive that it interferes with industrial operations on nearby lots.
   E.   Off-Street Parking and Off-Street Loading. As required in Section 1210 of the Custer City comprehensive plan.
   F.   Structures. Not more than one structure, other than accessory structures shall occupy a building site, provided all structural units comprising a motel stall be deemed to constitute one structure.
   G.   Foundations. All structures must be securely affixed to a permanent foundation.
   H.   Sewer and Water. All structures, other than accessory structures, must be served by municipal water and sewer facilities.
   I.   Accessory Structures. No private garage, carport or other accessory structure shall be located on a building site unless it is accessory to the main building also located on such building site. (Ord. 432 (part), 1995)