Any use hereafter established in the LI light industrial district shall conform to the following performance standards. Prior to an issuance of a building permit for new construction within this district or the issuance of a certificate of occupancy use for any use in this district, evidence that the proposed use, as planned or built will conform to these performance standards, shall be presented to the administrative official.
A. Smoke: No light industrial use may emit more than ten (10) smoke units per hour per stack or smoke in excess of Ringelmann no. 2. However, once during any twenty four (24) hour period, for soot blowing, process purging, and fire cleaning, each stack may emit an additional ten (10) smoke units, and during that time it may emit smoke up to and including Ringelmann no. 3.
Note: The term "Ringelmann number" means the number of the area on the Ringelmann chart that most nearly matches the light obscuring capacity of smoke. The Ringelmann chart is described in the U.S. bureau of mines information circular 8333, on which are illustrated graduated shades of gray for use in estimating smoke density. Smoke below the density of Ringelmann no. 1 shall be considered as no smoke or Ringelmann no. 0; and "smoke unit" means the number obtained when the smoke density in Ringelmann numbers is multiplied by the time of emission in minutes. For the purposes of this calculation, a Ringelmann density reading shall be made at least once a minute during the period of observation. Each reading shall then be multiplied by the time in minutes during which it is observed. The products so computed shall then be added to give the total number of smoke units observed during the entire observation period.
B. Odor: No light industrial use may release an odor that is either noxious or unreasonably disturbing.
C. Toxic Materials: For a light industrial use, the emission of toxic and noxious materials may not produce any concentration at a residence or business district boundary line exceeding three percent (3%) of the threshold limit values for toxic materials in industry as set forth in "threshold limit values" for the current year, as adopted at the annual meeting of the American Conference Of Governmental Industrial Hygienists.
D. Glare And Heat: No light industrial use may cause heat at the lot line so intense as to be a public nuisance or hazard. No such use may cause illumination at or beyond any residence district boundary in excess of one-tenth (1/10) foot-candle.
Note: The term "foot-candle" means a unit of illumination equal to the illumination at all points that are one foot (1') from a uniform point source of one candlepower.
E. Particulate Matter: The term "particulate matter" means divided liquid or solid material that is discharged and carried along in the air.
1. The rate of emission of particulate matter from all sources within the boundaries of any lot may not exceed a net figure of one pound per hour per acre for a light industrial use, of which no more than ten percent (10%) by weight may be particles larger than forty four (44) microns (325 mesh). The net rate of emission shall be computed by:
a. Determining the maximum emission in pounds per hour from each source of emission within the boundaries of the lot and dividing this figure by the number of acres of lot area, thus obtaining the gross hourly emission rate per acre for each source;
b. Deducting from that gross rate the appropriate correction factors for height of emission and stack velocity as respectively specified in subsections E2 and E3 of this section, thus obtaining the net hourly emission rate per acre from each source; and
c. Adding the individual rates of emission so computed to obtain the total net hourly emission rate per hour from all sources within the boundaries of the lot.
2. The allowance for height of emission is as follows (interpolate for intermediate values):
MAXIMUM HEIGHT FOR PARTICULATE MATTER EMISSION
Maximum Height, Above Grade (Feet) | Correction For Light Industrial Use (Pounds Per Hour Per Acre) |
Maximum Height, Above Grade (Feet) | Correction For Light Industrial Use (Pounds Per Hour Per Acre) |
50 | 0.01 |
100 | 0.06 |
150 | 0.10 |
200 | 0.16 |
300 | 0.30 |
400 | 0.50 |
500 and above | 0.50 |
3. The allowance for velocity of emission is as follows (interpolate for intermediate values):
ALLOWANCE FOR VELOCITY OF PARTICULATE MATTER EMISSION
Exit Velocity Up (Feet Per Second) | Correction For Light Industrial Use (Pounds Per Hour Per Acre) |
0 | 0 |
20 | 0.03 |
40 | 0.09 |
60 | 0.16 |
80 | 0.24 |
100 and above | 0.5 |
4. Dust and other kinds of air pollution that are borne by wind from such sources within lot boundaries as storage areas, yards, and roads shall be kept to a minimum by appropriate landscaping, paving, oiling, fencing, or other means.
F. Vibration:
1. No light industrial use may cause, at the lot line, continuous earthborn vibrations higher than the limits set forth in column I of the following table. Nor may it cause, at any residence district boundary, continuous earthborn vibrations higher than the limits set forth in column II of the following table.
MAXIMUM VIBRATION
Frequency (Cycle Per Second) | I | II | |
More Than | But Not More Than | Displacement | Displacement |
Frequency (Cycle Per Second) | I | II | |
More Than | But Not More Than | Displacement | Displacement |
0 | 10 | 0.0008 | 0.0004 |
10 | 20 | 0.0005 | 0.0002 |
20 | 30 | 0.0002 | 0.0001 |
30 | 40 | 0.0002 | 0.0001 |
40 | 50 | 0.0001 | 0.0001 |
50 | 0.0001 | 0.0001 | |
Note: The term "displacement" means the maximum amount of motion in any direction as determined by any three-component (simultaneous) measuring system approved by the administrative official; and "three-component measuring system" means instrumentation that can measure earthborn vibrations in a horizontal as well as a vertical plan.
2. Discrete pulses that do not exceed one hundred (100) impulses per minute may not produce higher than twice the displacement specified in the table.
G. Noise: The noise standards established in title 4, chapter 6 of this code shall be the noise standards for light industrial purposes.
H. Fire Hazards: Solid substances ranging from free or active burning to intense burning may be stored, used, or manufactured only within completely enclosed buildings having incombustible exterior walls and protected throughout by an automatic fire extinguishing system. The storage, utilization, or manufacture of flammable liquids or materials which produce flammable vapors or gases shall be permitted in accordance with the rules and regulations of the state fire marshal. A certificate of compliance, issued by the state fire marshal's office, stating that the plan and specifications for a light or general industrial use comply with the rules and regulations of the state fire marshal shall accompany the application for a zoning certificate.
I. Detonation Materials: No activity involving the storage or use of materials that decompose by detonation may be carried on except in accordance with the rules issued by the state fire marshal. No activity involving the manufacturing of materials that decompose by detonation may be carried on in this district. Materials that decompose by detonation include primary explosives such as lead azide, lead styphnate, fulminates, and tetracene; high explosives such as TNT, RDX, HMX, PETN, and picric acid; propellants and their components, such as nitrocellulose, black powder, boron hydrides, hydrazine and its derivatives; pyrotechnics and fireworks such as magnesium powder, potassium chlorate, and potassium nitrate; blasting explosives such as dynamite and nitroglycerine; unstable organic compounds, such as acetylides, tetrazoles, and ozonides; strong oxidizing agents such as liquid oxygen, perchloric acid, perchlorates, chlorates, and hydrogen peroxide in concentrations greater than thirty five percent (35%); and nuclear fuels, fissionable materials and products, and reactor elements such as uranium 235 and plutonium 239.
J. Exceptions: These performance standards do not apply to:
1. Site preparation or construction maintenance, repair, alteration or improvement of buildings, structures, equipment, or other improvements on or within the lot line;
2. Conditions beyond the control of the user such as fire, explosion, accident, failure or breakdown;
3. Safety or emergency warning signals or alarms necessary for the protection of life, limb, or property.
K. Open Storage: Open storage of materials shall be kept in a neat and orderly manner. Open storage shall not exceed fifteen feet (15') in height. All the open storage areas shall be screened from public view by a fence of at least six feet (6') in height. All open storage areas shall be paved with a dust free surface. (Ord. 2013-20)