It shall be unlawful for any person, firm, association or corporation to operate or maintain within any residential or commercial district of the City and County of San Francisco, as defined in and by zoning ordinances from time to time in force, any permanently located furnace, fire-box or other device whereby petroleum, coal or other substance is consumed by fire which emits or causes to be emitted dense smoke as hereinafter defined; provided, however, that dense smoke may be emitted for a period of one minute to afford the operator time to locate the cause of such smoke, and provided, further, that dense smoke may be emitted during a period or periods aggregating not more than 10 minutes in any one hour during which the fireboxes, flues or furnaces are being cleaned, a new fire is being started or fires are being increased or decreased in intensity; provided, further, that portable boilers shall have screen bonnet on smoke-stack which shall prevent the escape of unreasonable quantities of oil or soot. Smoke shall be considered dense within the meaning of this section when its density shall exceed the density designated as Diagram No. 3 upon the Ringelmann Smoke Chart published and used by the United States Bureau of Mines, a copy of which is on file in the office of the Clerk of the Board of Supervisors of the City and County of San Francisco.
It shall be unlawful for any person, firm, association or corporation within any residential or commercial district aforesaid to cause, permit or allow solid particles of soot, ashes or cinders to issue or be discharged from any flue, chimney or smokestack or from any other structure or appliance for such a period of time or in such quantities as to become a nuisance by reason of depositing such particles upon surrounding property.
It shall be unlawful for any person, firm, association or corporation within the City and County of San Francisco to cause, permit or allow objectionable fumes to issue or be discharged from any flue, chimney or smokestack from any other structure or appliance for such period of time or in such quantities as to become a nuisance on account of causing obnoxious odors in any residential or commercial district aforesaid.
It shall be unlawful for any person, firm, association or corporation within any commercial district aforesaid to erect, construct or maintain, or to cause or permit to be erected, constructed or maintained, any permanently located stationary flue, chimney, or smokestack within 50 feet of any window of any adjacent building unless the top of such flue, chimney or smoke-stack shall be higher than each portion of such window; provided, however, that this section shall not apply in any case where the persons owning and operating such adjacent building shall refuse to grant permission to brace or support such flue, chimney or smokestack by means of wire or struts attached to such building.
Representatives of the Department of Public Health of the City and County of San Francisco are hereby authorized to enter during reasonable hours upon any premises upon which is located any flue, chimney or smokestack or any other structure or appliance from which smoke, soot, ashes, cinders or fumes are discharged in violation of this section, for the purpose of making an examination as to the cause of the excessive discharge of such smoke, soot, ashes, cinders or fumes and the manner of using the same and any other fact or facts showing compliance with or violation of this section. Such representatives shall make report to the Department of Public Health of such examination within 10 days after receiving a complaint of violation of this Section.