(a) Permitted Uses. The following uses are permitted:
(1) Any use which may be permitted in the M-1 District.
(2) Any production, processing, cleaning, servicing, testing, repair or storage of materials, goods or products which conform to the performance standards established for this district, but not including any of the uses first listed as permitted in the M-3 Heavy Industrial District.
(b) Special Uses. The following uses may be allowed by special use permit:
(1) Any use which may be allowed as a special use in the M-1 District.
(2) Junk yards and automobile wrecking yards, provided they are contained within completely enclosed buildings or screened by a solid wall or uniformly painted solid fence at least twelve feet high.
(3) Stone and gravel quarries and crushing, grading, washing and loading equipment and structures.
(4) Railroad roundhouses, maintenance buildings and switching yards.
(c) Conditions of Use. All permitted uses are subject to the following conditions:
(1) All production, processing, cleaning, servicing, testing and repair or storage of goods, materials or products shall conform to the performance standards set forth in the M-1 District.
(2) Within 150 feet of a residence district, all business, production, servicing, processing and storage shall take place or be within completely enclosed buildings, except that storage of materials may be open to the sky, provided the storage area is enclosed with a solid wall or fence at least eight feet high.
However, within such 150 feet of a residence district, off-street loading facilities and off-street parking of motor vehicles under one and one-half tons capacity may be unenclosed, except for such screening of parking and loading facilities as may be required under the provisions of Chapter 1262.
(d) Yard Areas. All yard areas shall be the same as required in the M-1 Limited Manufacturing District.
(e) Maximum Floor Area Ratio. The maximum floor area ratio shall be 3.0.
(f) Signs. Signs shall be as permitted and allowed in Chapter 1468 of the Building and Housing Code.
(g) Performance Standards. Any use established hereafter in an M-2 General Manufacturing District shall be so operated as to comply with the performance standards set forth as follows:
(1) Noise. The performance standards governing noise in the M-1 District shall apply.
(2) Smoke and particulate matter.
A. No stack shall emit more than twenty smoke units during any one hour, nor shall smoke of a density in excess of Ringelmann No. 2 be emitted, provided that during fire cleaning periods, each stack may emit four minutes of smoke of up to thirty smoke units, twice for blowing soot and twice for cleaning fires, and during such cleaning of fires, smoke of a density of Ringelmann No. 3 may be emitted.
B. No emission of smoke or particulate matter shall exceed a density of Ringelmann No. 3, except for a plume consisting entirely of condensed steam. For the purpose of grading the density of emission, the Ringelmann Chart published and used by the United States Bureau of Mines shall be employed.
C. The rate of emission of particulate matter from all sources within the boundaries of any lot shall not exceed a net figure of three pounds per acre of lot area during any one hour, computed in accordance with procedures set forth herein.
D. Dust and other forms of air pollution borne by the wind, from such sources as storage areas, yards, roads and so forth, within lot boundaries, shall be kept to a minimum by appropriate landscaping, paving, oiling or other acceptable means. The emission of particulate matter from such sources shall conform to the requirements of paragraph (g)(2)C. hereof.
E. In addition to the performance standards specified herein, the emission of smoke or particulate matter in such manner or quantity as to be detrimental or endanger the public health, safety, comfort or welfare is hereby declared to be a public nuisance.
(3) Odorous matter. The emission of odorous matter from any property in such concentrations as to be readily detectable at any point along the boundaries of said property, when diluted in the ratio of one volume of odorous air to four or more volumes of clean air, or in such concentrations as to produce a public nuisance or hazard beyond the property boundaries, is prohibited.
(4) Vibration. Any process or equipment which produces intense earth-shaking vibrations, such as are created by heavy drop forges or heavy hydraulic surges, shall be set back at least 500 feet from the property boundaries on all sides, except for a property line adjoining an M-3 District, where such setback shall not be mandatory. However, in no case shall such vibrations be allowed to create a public nuisance or hazard beyond the property boundaries.
(5) Toxic or noxious matter. No use on any property shall discharge across the boundaries of said property toxic or noxious matter in such concentrations as to be detrimental to or endanger the public health, safety, comfort or welfare, or cause injury or damage to other property or business.
(6) Glare or heat. Any operation producing intense glare or heat shall be performed within an enclosure and effectively screened in such a manner as not to create a public nuisance or hazard along property boundaries.
(7) Fire and explosive hazards. Fire and explosive hazards shall be controlled as follows:
A. Activities involving the storage or manufacture of materials or products which decompose by detonation are not permitted in the M-2 District, unless licensed by the City. However, in no case shall such materials or products be stored or manufactured within 200 feet of the boundary of any other district, except an M-3 District.
B. The storage, utilization or manufacture of materials or products ranging from incombustible to moderate burning, as determined by the Zoning Administrator, is permitted.
C. The storage, utilization or manufacture of materials or products ranging from free to active burning to intense burning, as determined by the Zoning Administrator, is permitted, provided that within forty feet of the boundary of a residence or business district, the following restrictions shall apply:
1. All storage, utilization or manufacture of such materials or products shall be within completely enclosed buildings or structures having incombustible exterior walls; and
2. All such buildings or structures shall be protected throughout by an automatic sprinkler system complying with standards for installation prescribed by the National Fire Protection Association.
D. Materials or products which produce flammable or explosive vapors or gases under ordinary weather temperatures shall not be permitted in this district, with the exception of the following, which are permitted:
1. Materials required for emergency or standby equipment;
2. Materials used in secondary processes which are auxiliary to a principal operation, such as paint-spraying of finished products; and
3. Flammable liquids and oils stored, sold and used in conjunction with the operation of any automobile service station and customarily required or used in such operation.
(1977 Code § 73-902)