Packet: Tiffin City Council Work Session (09/15/2026)

CHAPTER 166 ESTABLISHMENT OF ZONING DISTRICTS AND THE OFFICIAL ZONING MAP (3) Smoke and Particulate Matter. The emission, from all sources within any lot, or particulate matter containing more than five percent by weight of particles having a particle diameter larger than 44 microns is prohibited. Dust and other types of air pollution borne by the wind from such sources as storage areas, yards, and roads within the boundaries of any lot must be kept to a minimum by appropriate landscaping, paving, oiling, or other acceptable means. Emission of particulate matter from such sources in excess of the weight limitations specified herein is prohibited. The emission of smoke or particulate matter of a density or equivalent opacity equal to, or greater than, Ringelmann Chart No. 2, is prohibited at all times, except as otherwise provided herein. (The Ringelmann Chart is the chart published by the United States Bureau of Mines.) a. Smoke Emission. In the C-1S District, the emission of more than 12 smoke units per stack in any one-hour period is prohibited. However, once during any six-hour period each stack shall be permitted up to 12 additional units in a 15-minute period for soot blowing and fire cleaning. Only during such 15-minute periods shall smoke of a density or equivalent opacity equal to, but not exceeding, Ringelmann Chart No. 3 be permitted, and then only for fire cleaning and for not more than four minutes per period. b. Particulate Matter. The rate of emission of particulate matter from all sources within the boundaries of any lot shall not exceed the rate established in the following table: Maximum Permitted Particulate Matter Emission Rate Height of Emissions Pounds per Hour (ft) (Per Acre) 0-49 1.00 50-99 1.01 100-149 1.06 150-199 1.10 200-299 1.16 300-399 1.30 400-over 1.50 c. Method of Measurement. i. “Smoke.” To grade the density or equivalent opacity of emission of smoke, the Ringelmann Chart shall be employed. To determine smoke units, the Ringelmann reading shall be made at least every minute during the period of observation. Each reading (Ringelmann number) shall be multiplied by the time in minutes for which it is observed, and the products added together to determine the total number of smoke units observed during the total period of observation. CODE OF ORDINANCES, TIFFIN, IOWA - 1691 -