(a) “M-1” and “M-2” Districts. Required Conditions.
1. Air Pollution. In an “M-1” or “M-2” District no use shall be permitted which emits any air pollution beyond the boundaries of the site which is detectable by the human senses without the aid of instruments. The provisions of this section relating to air pollution shall not apply to any use maintained in compliance with the conditions of a use permit issued after January 1, 1964 and prior to May 18, 1965.
2. Smoke. In an “M-1” District no use shall be permitted which emits smoke. In an “M-2 District no use shall emit visible gray smoke of a shade equal to or darker than No. 2 on a standard Ringlemann Chart issued by the United States Bureau of Mines or smoke of an equivalent opacity, except that smoke of a shade equal to No. 3 on a Ringlemann Chart, or smoke of an equivalent opacity, may be emitted for four minutes in any 30-minute period. The provisions of this section relating to smoke shall not apply to any use maintained in compliance with the conditions of a use permit issued after January 1, 1964, and prior to May 18, 1965.
3. Solid and Liquid Wastes. No solid or liquid wastes shall be discharged into a public or private sewerage system except in compliance with the regulations prescribed by the Board of Supervisors or by the governing boards of other governmental agencies or in compliance with the regulations of the owner of the system.
4. Odor. In an “M-1” District no use except a temporary construction operation shall be permitted which creates odor beyond the boundaries of the site which is detectable by the human senses without the aid of instruments. In an “M-2” District no use except a temporary construction operation or a seasonal fruit or vegetable dehydrating or processing plant shall be permitted which creates odor beyond the boundaries of the site which is found by the Planning Commission to be offensive or which is detectable beyond the boundaries of the “M-2” District without the aid of instruments.
5. Noise. In an “M-1” or “M-2” District no use except a temporary construction operation shall be permitted which creates noise which is found by the Planning Commission not to conform to the noise parameters established by the Land Use Compatibility Chart for Exterior Community Noise (General Plan Figure 6-1) beyond the boundaries of the “M-1” or “M-2” District at standard atmospheric pressure.
6. Vibration, Heat and Cold, Glare, Electrical Disturbance. No use except a temporary construction operation shall be permitted which creates vibration, changes in temperature, direct or sky-reflected glare, or electrical disturbance which is detectable by the human senses without the aid of instruments beyond the boundaries of the site in an “M-1” District or beyond the boundaries of the district in an “M-2” District.
7. Nonconformance with Provisions of Section 13.10.345(a). Any use listed in Section 13.10.342(b) which is located in an “M-1” District which is found by the Planning Commission not to comply with the requirements of Section 13.10.345(a) shall constitute a nonconforming use. The Planning Commission’s determination that such use is nonconforming shall be made after public hearing is held more than 15 days after written notice to the user.
8. Actions Necessary to Make a Nonconforming Use Conform. In order for a nonconforming use to be made conforming, a Use Approval processed at the appropriate level as indicated in the Use Chart, shall be obtained pursuant to Section 13.10.220. Application for the Use Approval must be made within three months of the date the Planning Commission determines the use to be nonconforming. If an application for a Use Approval has not been filed within the three month period, the nonconforming use shall thereafter be subject to the abatement proceedings set forth in Chapter 1.14, provided that no additional public hearing shall be required by the Planning Commission prior to making its recommendation to the Board of Supervisors.
(b) Special Findings for High Impact Uses in the “M-1” District. Any uses listed as allowed in the “M-2” District may be allowed as discretionary uses in the “M-1” District provided that the Zoning Administrator or Planning Commission makes the following findings in addition to the findings required for a development permit pursuant to chapter 18.10.
1. That consideration of all the determinable characteristics of the use which is the subject of the application indicates that the use has the same essential characteristics as the permitted uses in an “M-1” District with respect to method of operation, type of process, materials, equipment, structures, storage and appearance.
2. That the use will not create significantly more vehicular or rail traffic than the volumes normally created by the permitted uses in an “M-1” district.
3. That the use will not generate odor, fumes, dust, smoke, particles, dirt, refuse, water-carried wastes, noise, vibration, glare, heat, or any other objectionable factor beyond the boundaries of the site, or be unsightly or create a hazard of fire or explosion.
(c) “M-3” Districts. Required Findings for Uses Other than Mineral Extraction. In addition to findings required for a Development Permit, the Approving Body shall find that the proposed use is located, or will be conducted in a manner so as to not preempt the ultimate extraction or use of any rock, sand, gravel or mineral resource. Special use requirements and standards for mining and related uses in the “M-3” zone district are found in Chapter 16.54 Mining Regulations.
(d) Prohibitions. The following uses and activities are prohibited in Industrial districts:
1. Asbestos. In an “M-1,” “M-2,” “M-3” District, no use shall be permitted which produces or uses asbestos in any manufacturing process. (Ord. 839, 11/28/62; 1087, 5/18/65; 2681, 4/17/79; 2759, 9/4/79; 3152, 8/25/81; 3186, 1/12/82; 3344, 11/23/82; 3432, 8/23/83; 3479, 11/28/83; Ord. 4496-C, 8/4/98; Ord. 4761 § 25, 5/18/04)