A light industrial use is one which creates a minimum amount of nuisance outside the plant; is conducted entirely within enclosed buildings, does not use the open area around such buildings for storage of raw materials or manufactured products or for any other industrial purpose other than transporting goods between buildings; provides for enclosed loading and unloading berths; and such use conforms to the following performance standards:
(a) Smoke. The emission of more than ten (10) smoke units per hour per stack and emissions in excess of Ringelmann No.2 are prohibited. However, once during any twenty-four (24) hour period for soot blowing, process purging and fire cleaning, each stack shall be permitted an additional ten smoke units, during which time smoke up to and including Ringelmann No. 3 is permitted.
(b) Particulate Matter. The rate of emission of particulate matter from all sources within the boundaries of any lot shall not exceed a net figure of one pound per hour per acre, of which no more than ten percent (10%) by weight of particles larger than forty-four microns (325 mesh) shall be allowed. Determination of the total net rate of emission shall be made as follows:
(1) Determine the maximum emission in pounds per hour for each source of emission and divide this figure by the number of acres of lot area, thus obtaining a gross hourly emission rate per acre.
(2) Deduct from the gross rate derived above, the appropriate correction factors for height of stack and stack velocity as listed in Tables I and II hereof, thus obtaining the net rate of emission in pounds per hour per acre of each source.
(3) Add together the individual rates of emission derived above of each source to obtain the total net rate of emission from all sources within the boundaries of the lot. Dust and other types of air pollution, borne by the wind from such sources as storage areas, yards, roads and the like within lot boundaries, shall be kept to a minimum by appropriate landscaping, paving, oiling, fencing or other acceptable means.
(c) Odor. No activity or operation shall permit odors to be released which shall be detectable at the lot line.
(d) Toxic and Noxious Materials. The emission of toxic and noxious materials shall not exceed the quantities determined by the following formula:
Q = 36 Cx2
Q is the maximum permitted quantity of toxic material emitted in the four-hour period having the greatest average concentration (cubic feet);
TABLE I
Allowance for Height of Emission*
Height of Emission Above Grade (Feet) | Correction (Pounds per Hour per Acre) |
50 | 0.01 |
100 | 0.06 |
150 | 0.10 |
200 | 0.16 |
300 | 0.30 |
400 and above | 0.50 |
TABLE II
Allowance for Velocity of Emission*
Exit Velocity Up (Feet per Second) | Correction (Pounds per Hour per Acre) |
0 | 0 |
20 | 0.03 |
40 | 0.09 |
60 | 0.16 |
80 | 0.24 |
100 and above | 0.50 |
*Interpolate for intermediate values.
C is the threshold limit value of toxic materials in industry (parts per million by volume) as set forth in "Threshold Limit Values for Toxic Materials in Industry" issued by the West Virginia Department of Health*; x is the nearest distance in thousands of feet of the stack, vent, flue or other discharge point to a residence or business district boundary line
( ft).
1000
When C is given as milligrams per cubic meter, multiply this figure by 0. 061, place it in the above formula and obtain Q in pounds permitted in four (4) hours. if the material is emitted from open piles, ponds, tanks. areas, etc., the maximum permitted concentration measured at a residence district boundary line shall be ten percent (10%) of the threshold limit value C.
(e) Glare and Heat. No industrial operation, activity or structure shall cause intense heat in such a manner as to be a public nuisance or hazard across lot lines. No industrial operation, activity or structure shall cause illumination at or beyond any residence district boundary in excess of 0.1 foot candle.
(f) Vibration. Any industrial operation or activity which shall cause at any time and at any point along the nearest adjacent lot line, earth borne vibrations in excess of the limits set forth in Column I (below) are prohibited. in addition, any industrial operation or activity which shall cause at any time and at any point along a residence district boundary line, earth borne vibrations in excess of the limits set forth in Column II are prohibited. Vibration shall be expressed as resultant displacement in inches.
I | II | |
Frequency (Cycles Per Second) | Displacement (Inches) | Displacement (Inches) |
Below 10 10 to 20 20 to 30 30 to 40 40 and over | .0008 .0005 .0002 .0002 .0001 | .0004 .0002 .0001 .0001 .0001 |
The above tabulation is for steady state vibration defined as continuous vibration in contrast to discrete pulses. Impact vibration, that is, discrete pulses which do not exceed one hundred (100) impulses per minute, shall not produce in excess of twice the displacement stipulated above.
*From the American Conference of Governmental Hygienists, American Medical Association, Archives of industrial Health, published August, 1958.
(g) Noise. At no point on the boundary of a residence or business district shall the sound pressure level of any operation or plant, other than background noises produced by sources not under control of this Ordinance, such as the operation of motor vehicles or other transportation facilities exceed the decibel limits in the octave bands designated below:
Octave Band Frequency (Cycles Per Second) | I Maximum Permitted Sound Level (In Decibels) Along Residence District Boundaries | II Maximum Permitted Sound Level (In Decibels) Along Business District Boundaries |
20 to 75 75 to 150 150 to 300 300 to 600 600 to 1200 1200 to 2400 2400 to 4800 Above 4800 | 72 67 59 52 46 40 34 32 | 79 74 66 59 53 47 41 39 |
The prescribed limits of Column I are applicable between the hours of 8:00 a.m. and 6:00 p.m. At other times the allowable levels shall be reduced by six decibels in every octave band.
Sound levels shall be measured with a sound-level meter and associated octave band filter, manufactured in compliance with standards prescribed by the American National Standards Institute. When sounds are of such short duration as not to be measured accurately with the sound-level meter, the impact noise analyzer as manufactured under standards of the American National Standards institute shall be used to determine the peak value of the impact. Impacts shall meet the noise performance standards.
(h) Fire Hazards. The storage, utilization or manufacture of solid materials or products ranging from incombustible to moderate burning is permitted.
The storage, utilization or manufacture of solid materials or products ranging from free or active burning to intense burning is permitted provided the following condition is met: Such materials or products shall be stored, utilized or manufactured 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 gases* which produce flammable or explosive vapors, shall be permitted in accordance with TABLE III, exclusive of storage of finished products in original sealed containers:
TABLE III
Total capacity of flammable materials permitted, gallons*
Industries engaged in Storage and Distribution | Above Ground | Under Ground |
Materials having a flash point above 190°F |
Prohibited | 100,000 |
From and including 105°F to and including 190°F |
Prohibited | 40,000 |
Materials having a flash point below 105°F |
Prohibited | 20,000
|
Industries engaged in Utilization and Manufacture | ||
Materials having a flash point above 190°F |
10,000 | 50,000 |
From and including 105°F to and including 190°F |
1,000 | 20,000 |
Materials having a flash point below 105°F |
500 | 10,000
|
(Footnote for 1331.04(h) and Table III.)
*When flammable gases are stored, utilized or manufactured and measured in cubic feet, the quantity in cubic feet (at S. T. P.) permitted shall not exceed three hundred (300)times the quantities listed above. (1969 Code §27-37)