The following performance standards for Limited and General Industrial Districts are designed to reduce the impact of industrial districts on surrounding uses by lessening traffic congestion, protecting the health and safety of workers and nearby residents, and by preventing detrimental effects on properties adjoining or in the neighborhood. All applications for a site plan approval must be accompanied by a registered engineer's certification that the use complies with all of the applicable standards. Upon receipt of the certification, the Zoning Administrator will issue a zoning certificate. After occupancy, if there occurs continuous or frequent, even though intermittent, violations of the performance standards and provisions of these regulations without bona fide and immediate corrective work, the Zoning Administrator will suspend or revoke the zoning certificate of the use and the operation shall immediately cease until it is able to operate in accordance with this chapter, at which time the zoning certificate shall be reinstated.
(A) Storage and operations.
(1) In the LI District all operations and the storage of equipment, materials or products will be conducted within completely enclosed buildings or storage may be permitted outdoors only when completely screened by a wall, opaque fence, or planting so that such materials will not be visible from a public way or adjoining property. The Planning Commission shall determine the most appropriate screening for the use. The Planning Commission may waive or modify the requirement for complete screening between adjoining properties where the adjoining properties are similar in use and reduction or elimination of complete screening will not adversely impact adjoining properties.
(2) (a) In the GI District, a use is permitted either indoors or outdoors but in conformance with the following.
(b) Storage. Storage in a GI District within 500 feet of a residential district boundary may be outdoors but will be effectively screened by a solid wall, fence, or planting so that the materials will not be visible from the Residential District.
(B) Noise.
(1) Noise will be measured with a sound level meter. Impact noise will be measured using the fast response of the sound level meter. Impact noises are intermittent sounds such as from a punch press or drop force hammer.
(2) The following table describes the maximum sound pressure level permitted from any industrial source and measured in any adjacent Residential District, Commercial District, or LI Limited Industrial Lot.
Maximum permitted sound levels, dB(A) | ||||
Sound Measured to: | Decibels Continuous Slow Meter Responses | Impact Fast Meter Response | ||
LI | GI | LI | GI | |
Residential District | 55 | 55 | 60 | 60 |
Commercial District | 64 | 64 | 70 | 75 |
LI District lot, adjacent to noise source | 70 | 75 | 80 | - |
(3) The following sources of noise are exempt.
(a) Transportation vehicles not under the control of the industrial use.
(b) Occasionally used safety signals, warning devices, and emergency pressure relief valves.
(c) Temporary construction activity between 7:00 a.m. and 7:00 p.m.
(C) Vibration. No vibration will be produced which is transmitted through the ground and is discernible without the aid of instruments at or any point beyond the lot line; nor will any vibration produce a particle velocity of 2 inches per second measured at or beyond the lot line.
(D) Dust and particulates.
(1) The total emission rate of dust and particulate matter from all vents, stacks, chimneys, flues or other opening or any process, operation, or activity except solid waste incinerators within the boundaries of any lot, will not exceed the levels set forth below. Emissions of dust and particulates shall be in accordance with the State of Maryland rules and regulations governing air contamination and air pollution, and, in case of conflict, the most restrictive will apply.
(2) Particulate matter emission from materials or products subject to becoming windborne will be kept to a minimum by paving, sodding, oiling, wetting, covering or other means, such as to render the surface wind resistant. Such sources include vacant lots, unpaved roads, yards and storage piles or bulk material such as coal, sand, cinders, slag, sulfur, and the like.
Ambient Air Quality Standard (LI and GI Districts)
Particulate Matter
Suspended
Annual arithmetic mean, ug/m3 65
24-hour maximumb, ug/m3 140
Settleable
Annual arithmetic average, mg/cm/2/month 0.35
Monthly maximum 0.7
(E) Sulfur oxides. Emission of oxides of sulfur (as sulfur dioxide) from combustion and other processes will be limited in accordance with ambient air quality standards of the state or those of the county, whichever are the more restrictive.
Ambient Air Quality Standard (LI and GI Districts)
Sulfur Oxides
Annual arithmetic mean, ug/m3 60
(F) Smoke. For the purpose of grading the density or equivalent capacity of smoke, the Ringelmann Chart as published by the United States Bureau of Mines shall be used.
(1) LI District. The emission of smoke darker than Ringelmann No. 1 from any chimney, stack, vent, opening, or combustion process is prohibited.
(2) GI District. The emission of smoke darker than Ringelmann No. 1 from any chimney, stack, vent, opening, or combustion process is prohibited; however, smoke of a shade not to exceed Ringelmann No. 2 is permitted for up to 4 minutes total in any 1 hour period.
(G) Odor. Odor thresholds shall be measured in accordance with ASTM d1391-57 "Standard Method for Measurement of Odor in Atmospheres (Dilution Method)" or its equivalent.
(1) LI District. Odorous material released from any operation or activity shall not exceed the odor threshold concentration beyond the lot line, measured either at ground level or habitable elevation.
(2) GI District. Odorous materials released from any operation or activity shall not exceed the odor threshold concentration at or beyond the district boundary line measured either at ground level or habitable elevation.
(H) Toxic matter. The ambient air quality standards for the State of Maryland shall be the guide to the release of airborne toxic materials across lot lines. Where toxic materials are not listed in the ambient air quality standards of the state, the release of such materials shall be in accordance with the fractional quantities permitted below, of those toxic materials currently listed in the threshold limit values adopted by the American Conference of Governmental Industrial Hygienists. Unless otherwise stated, the measurement of toxic matter shall be at ground level or habitable elevation, and shall be the average of any 24 hours sampling period.
(1) LI District. The release of airborne toxic matter will not exceed one-thirtieth of the threshold limit value across lot lines.
(2) GI District. The release of airborne toxic matter shall not exceed one-thirtieth of the threshold limit value beyond the district boundary line.
(I) Detonable materials.
(1) Activities involving the storage, utilization or manufacture of products which decompose by detonation shall be in accordance with these new regulations.
(2) Such materials shall include but are not limited to: all primary explosives such as lead azide, lead styphnate, fulminates and tetracene; all high explosives such as TNT, RDX, HMX, PETN, and picric acid; propellants and components thereof, such as dry 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; unstable oxidizing agents such as perchloric acid, perchlorates, and hydrogen peroxide in concentration greater than 35%; and nuclear fuels, fissionable materials and products, and reactor elements such as Uranium 235 and Plutonium 239.
(a) LI District. The storage, utilization or manufacture of materials or products which decompose by detonation is prohibited.
(b) GI District. The manufacture of materials or products which decompose by detonation is limited to 5 pounds; however, such materials may be stored or utilized in any quantity.
(J) Fire hazards. Solid materials susceptible to fire hazards shall be subject to the following.
(1) LI District. The storage, utilization or manufacture of solid materials which are active to intense burning shall be conducted within spaces having fire resistive construction of no less than 2 hours and protected with an automatic fire extinguishing system.
(2) GI District. The storage, utilization or manufacture of solid materials which are active to intense burning shall be conducted within walls having a fire resistance no less than 2 hours or protected by an automatic fire extinguishing system or the building shall be no less than 40 feet from all lot lines. The outdoor storage of such materials shall be permitted no closer than 50 feet from all lot lines.
(3) Liquified petroleum gas (LP-gas) and flammable/combustible liquids within the LI and GI Districts shall adhere to the following standards:
(a) The total storage capacity of LP-gas shall not exceed 1,000,000 gallons on any site.
(b) The total storage capacity of flammable/combustible liquids shall not exceed 300,000 gallons.
(c) On-site blending of fuels is not permitted.
(d) The facility shall meet or exceed the requirements of:
1. The Frederick County Fire Prevention Code, as amended; and
2. The Following National Fire Protection Association (NFPA) Standards as adopted by reference, with local amendments, in the Frederick County Fire Prevention Code:
(i) NFPA 58 (Standard for the Storage and Handling of Liquefied Petroleum Gases), as amended;
(ii) NFPA Standard 30 (Flammable and Combustible Liquids Code), as amended;
(iii) NFPA Standard 30A (Code for Motor Fuel Dispensing Facilities and Repair Garages), as amended.
(e) A minimum lot area of 5 acres is required for a petroleum product storage facility with product storage capacity of 300,000 gallons or more.
(4) Notwithstanding the above-listed capacities for flammable liquids and gases, an owner or operator shall be permitted to exceed such capacities provided that the Zoning Administrator determines that the excess storage capacity is for an emergency fuel supply only. For purposes of this section, the term EMERGENCY FUEL SUPPLY means any fuel that is stored on site for use solely in the event of a disruption in the normal fuel supply. In no event shall the total storage capacity for an emergency fuel supply approved pursuant to this subsection exceed that amount of fuel required to operate the subject facility for a maximum of 5 consecutive 24 hour periods. The facilities to hold an emergency fuel supply shall be designed, constructed, and operated in compliance with the Frederick County Fire Prevention Code, § 1-2-69.1 of the Frederick County Code and the National Safety Codes and standards applicable to the specific emergency fuel.
(Ord. 77-1-78, § 40-62(F), 1-24-1977; Ord. 77-10-87, 8-22-1977; Ord. 86-49-426, 9-23-1986; Ord. 97-20-198, 12-16-1997; Ord. 08-26-502, 10-14-2008; Ord. 10-01-536, 1-19-2010; Ord. 11-06-572, 5-17-2011; Ord. 11-25-591, 10-27-2011; Ord. 14-23-678, 11-13-2014)