Virginia Administrative Code

Database updated through January 6, 2011

Article 4 

Insignificant Activities 

9VAC5-80-710. General. 

A. For the purposes of Article 1 (9VAC5-80-50 et seq.), Article 2 (9VAC5-80-310 et seq.) and Article 3 

(9VAC5-80-360 et seq.) of this chapter, insignificant activities shall be those activities listed in 9VAC5-80-

720. There are three categories of insignificant activities as follows: 

1. Insignificant emissions units. This category includes emissions units that are deemed 

insignificant because they are sufficiently small so as to be considered insignificant for the purpose 

of identifying the emissions units in permit applications. Emissions units in this category are not 

required to be included in permit applications submitted pursuant to Article 1 (9VAC5-80-50 et 

seq.) or Article 3 (9VAC5-80-360 et seq.) of this chapter. Insignificant activities falling into this 

category are listed in 9VAC5-80-720 A. 

2. Emissions units with insignificant emissions levels. This category includes emissions units, other 

than those in subdivision A 1 of this section, that are deemed insignificant because they have 

emissions levels sufficiently small so as to be considered insignificant for the purpose of 

quantifying the emissions from the emissions units in a permit application. Emissions units emitting 

at these insignificant levels are required to be identified by listing them as insignificant emissions 

units in the permit application submitted pursuant to Article 1 (9VAC5-80-50 et seq.) or Article 3 

(9VAC5-80-360 et seq.) of this chapter. The list of insignificant emissions units shall also specify 

the pollutant or pollutants emitted at insignificant emissions levels for each emissions unit on the 

list. However, information on the amount of emissions from these units is not required to be 

provided. Insignificant activities in this category are listed in 9VAC5-80-720 B. 

3. Emissions units of an insignificant size or production rate. This category includes emissions 
units, other than those in subdivision 1 or 2 of this subsection, that are deemed insignificant 

because the emissions from these units are considered to be of minimal or no air quality concern 

for the purpose of quantifying the emissions from the emissions units in a permit application. 

Emissions units in this category are required to be identified by listing them as insignificant 

emissions unit in the permit application submitted pursuant to Article 1 (9VAC5-80-50 et seq.) or 

Article 3 (9VAC5-80-360 et seq.) of this chapter. The list of insignificant emissions units shall also 

specify the size or the production rate for each emissions unit on the list. Insignificant activities in 

this category are listed in 9VAC5-80-720 C. 

4. Regardless of the emissions units designated in 9VAC5-80-720 A, B, or C, the emissions from 

any emissions unit should be included in the permit application submitted pursuant to Article 1 

(9VAC5-80-50 et seq.) or Article 3 (9VAC5-80-360 et seq.) of this chapter if the omission of those 

emissions units would interfere with the determination of applicability of Article 1 (9VAC5-80-50 et 

seq.) or Article 3 (9VAC5-80-360 et seq.) of this chapter, the determination of or imposition of any 

applicable requirement, or the calculation of permit fees. 

B. Definitions. 

1. For the purpose of this article and subsequent amendments issued by the board, the words or 

terms shall have the meanings given them in subdivision 2 of this subsection. As used in this 

article, all terms not defined here shall have the meanings given them in 9VAC5 Chapter 10 

(9VAC5-10-10 et seq.), unless otherwise required by context. 

2. Terms defined. 

"Uncontrolled emissions" means the emissions from a source when operating at maximum 

capacity without air pollution control equipment. Air pollution control equipment includes control 

equipment which is not vital to its operation, except that its use enables the source to conform to 

applicable air pollution control laws and regulations. Annual uncontrolled emissions shall be based 

on the maximum annual rated capacity (based on 8,760 hours of operation per year) of the source, 

unless the source is subject to state and federally enforceable permit conditions which limit the 
annual hours of operation. Enforceable permit conditions on the type or amount of material 

combusted or processed may be used in determining the uncontrolled emissions of a source. 

Secondary emissions do not count in determining the uncontrolled emissions of a stationary 

source. 

Statutory Authority 

§ 10.1-1308 of the Code of Virginia. 

Historical Notes 

Derived from Virginia Register Volume 12, Issue 25, eff. October 15, 1996. 

9VAC5-80-720. Insignificant activities. 

A. Insignificant activities include the following emissions units: 

1. Gas flares or flares used solely to indicate danger to the public. 

2. Ventilation systems not used to remove air contaminants generated by or released from specific 

units of equipment. 

3. Air-conditioning units used for human comfort that do not have applicable requirements under 

Title VI of the Act. 

4. Portable heaters which can reasonably be relocated through the manual labor of one person. 

5. Portable electrical generators that can be moved by hand from one location to another. 

6. Space heaters operating by direct heat or radiant heat transfer, or both. 

7. Office activities and the equipment and implements used to carry out these activities, such as 

typewriters, printers, and pens. 

8. Tobacco smoking rooms and areas. 

9. Interior maintenance activities and the equipment and supplies used to carry out these activities, 

such as janitorial cleaning products and air fresheners, but not cleaning of production equipment. 

10. Architectural maintenance and repair activities conducted to take care of the buildings and 
structures at the facility, including repainting, reroofing and sandblasting, where no structural 

repairs are made in conjunction with the installation of new or permanent facilities. 

11. Repair or maintenance shop activities not related to the source's primary business activity, not 

including emissions from surface coating or degreasing (solvent metal cleaning) activities, and not 

otherwise triggering a permit modification. 

12. Exterior maintenance activities conducted to take care of the grounds of the source, including 

lawn maintenance. 

13. Internal combustion engines used for dry-cleaning and steam boilers. 

14. Laundry activities, except for dry-cleaning and steam boilers. 

15. Bathroom and locker room ventilation and maintenance. 

16. Copying and duplication activities for internal use and support of office activities at the source. 

17. Blueprint copiers and photographic processes used as an auxiliary to the principal equipment 

at the source. 

18. Equipment used solely for the purpose of preparing food to be eaten on the premises of 

industrial and manufacturing operations. 

19. Equipment used exclusively to slaughter animals, but not including other equipment at 

slaughterhouses, such as rendering cookers, boilers, heating plants, incinerators, and electrical 

power generating equipment. 

20. Safety devices. 

21. Air contaminant detectors and test equipment. 

22. Brazing, soldering or welding equipment used as an auxiliary to the principal equipment at the 

source. 

23. The engine of any vehicle, including but not limited to any marine vessel, any vehicle running 

upon rails or tracks, any motor vehicle, any forklift, any tractor, or any mobile construction 

equipment, including any auxiliary engine that provides cooling or refrigeration of the vehicle. 
24. Fugitive emissions related to movement of passenger vehicles, provided the emissions are not 

counted for applicability purposes and any required fugitive dust control plan or its equivalent is 

submitted. 

25. Emergency road flares. 

26. Firefighting equipment and the equipment used to train firefighters. 

27. Fire suppression systems. 

28. Laboratories used solely for the purpose of quality control or environmental compliance testing 

that are associated with manufacturing, production or other industrial or commercial facilities. 

29. Laboratories in primary and secondary schools and in schools of higher education used for 

instructional purposes. 

30. Bench-scale laboratory equipment used for physical or chemical analysis, but no lab fume 

hoods or vents. 

31. Routine calibration and maintenance of laboratory equipment or other analytical instruments. 

32. Air compressors and pumps (engines for these emissions units are covered separately under 

subdivision C 1 of this section). 

33. Pneumatically operated equipment, including hand tools. 

34. Emergency (backup) electrical generators at residential locations. 

35. Dumpster. 

36. Grinding or abrasive blasting for nondestructive testing of metals. 

37. Dryers and distribution systems for instrument air. 

38. Parts washer (water-based). 

39. Electric or steam-heated drying ovens and autoclaves, but not the emissions from the articles 

or substances being processed in the ovens or autoclaves or the boilers delivering the steam. 

40. Salt baths using nonvolatile salts that do not result in emissions of any regulated air pollutants. 
41. Dispensing facilities for refueling diesel-powered vehicles or equipment, including any diesel 

fuel storage tank serving only such dispensing facility, to the extent that this activity is not regulated 

by § 111 or § 112 of the federal Clean Air Act. 

42. Storage tanks, vessels, and containers holding or storing liquid substances that will not emit 

any volatile organic compound or hazardous air pollutant. 

43. Storage tanks, reservoirs, and pumping and handling equipment of any size containing soaps, 

vegetable oil, grease, animal fat, and nonvolatile aqueous salt solutions, provided appropriate lids 

and covers are utilized. 

44. Equipment used to mix and package soaps, vegetable oil, grease, animal fat, and nonvolatile 

aqueous salt solutions, provided appropriate lids and covers are utilized. 

45. Laboratory analytical equipment and vents except at stationary sources primarily engaged in 

research and development. 

46. Equipment used for quality control/assurance or inspection purposes, including sampling 

equipment used to withdraw materials for analysis. 

47. Nonroutine clean out of tanks and equipment for the purposes of worker entry or in preparation 

for maintenance or decommissioning. 

48. Sampling connections and systems used exclusively to withdraw materials for testing and 

analysis including air contaminant detectors and vent lines. 

49. Vents from continuous emission monitors and other analyzers. 

50. Maintenance activities such as hand-held or manually operated maintenance equipment, 

railroad track maintenance, repair and maintenance cleaning, and maintenance surface 

preparation activities. 

51. Hand-held equipment for buffing, polishing, cutting, drilling, sawing, grinding, turning, or 

machining wood, metal, or plastic. 

52. Carbon monoxide lasers used only on metals and other materials which do not use hazardous 
air pollutants in the process. 

53. Hand-held applicator equipment for hot melt adhesives with no volatile organic compounds in 

the adhesive formulation. 

54. Equipment used for surface coating, painting, dipping, or spraying operations, except those 

that emit volatile organic compounds or hazardous air pollutants. 

55. Drop hammers or hydraulic presses for forging or metalworking. 

56. Blacksmith forges. 

57. Solvent storage cabinet (containers covered). 

58. Cooling ponds. 

59. Coal pile run-off ponds. 

60. Mechanical drive or gear boxes. 

61. Equipment for steam cleaning or brushing dust off equipment. 

62. Repair of residential units. 

63. Farm equipment, with the exception of grain elevators or combustion devices not already listed 

as insignificant activities. 

64. Water tanks. 

65. Hydroblasting. 

66. Hydraulic and hydrostatic testing equipment. 

67. Process raw water treatment (e.g., phosphate). 

68. Process water filtration systems and demineralizers. 

69. Demineralized water tanks and demineralizer vents. 

70. Ozone generators. 

71. Water cooling tower except for systems including contact process water or water treated with 

chromium-based chemicals. 
72. Spill collection tanks. 

73. Steam vents and leaks from boilers and steam distribution systems. 

74. Boiler water treatment operations, except cooling towers and those involving use of hydrazine. 

75. Oxygen scavenging (de-aeration) of water. 

76. Herbicide mixing and application activities not involving herbicide manufacture. 

77. Nonhazardous boiler cleaning solutions. 

78. Portable or mobile containers. 

79. Vent or exhaust system for: 

a. Transformer vaults and buildings; 

b. Electric motor and control panel vents; and 

c. Deaerators and decarbonators. 

80. Vents or stacks for sewer lines or enclosed areas required for safety or by code. 

81. Pump seals. 

82. Rupture discs for gas handling systems. 

83. Molasses storage tanks. 

84. Storage of substances in closed drums, barrels or bottles. 

85. Purging of natural gas lines. 

86. Natural gas pressure regulator vents, excluding venting at oil and gas production facilities. 

87. Blanking, chopping, trimming, perforating, repacking, and inspecting in connection with plastics 

manufacturing processes. 

88. Consumer use of paper trimmers/binders. 

89. Laser trimmers using dust collection to prevent fugitive emissions. 

90. Sealed batteries such as those used for emergency backup power supplies. 
91. Batteries and battery charging stations, except at battery manufacturing plants. 

92. Parking lot resurfacing. 

93. Environmental chambers not using hazardous air pollutant gases. 

94. Shock chambers. 

95. Humidity chambers. 

96. Solar simulators. 

97. Relief valves, excluding air pollution equipment bypass valves. 

98. Steam vents and safety relief valves. 

99. Steam leaks. 

100. Steam cleaning operations. 

101. Steam sterilizers. 

B. Insignificant activities include emissions units, other than those listed in subsection A of this section, 

with the following emissions levels: 

1. Emissions units with uncontrolled emissions of less than five tons per year of nitrogen dioxide, 

sulfur dioxide, or particulate matter (PM10). Particulate matter emissions shall be used to determine 

uncontrolled emissions for purposes of this subsection only if particulate matter (PM10) emissions 

cannot be quantified in a manner acceptable to the board. If the particulate matter (PM10) 

emissions for any unit can be quantified in a manner acceptable to the board, that unit shall be 

deemed insignificant for particulate matter; 

2. Emissions units with uncontrolled emissions of less than five tons per year of volatile organic 

compounds; 

3. Emissions units with uncontrolled emissions of less than five tons per year of carbon monoxide; 

4. Emissions units with uncontrolled emissions of less than 0.6 tons per year of lead; 

5. Emissions units with uncontrolled emissions of hazardous air pollutants at or below 1,000 
pounds per year; 

6. Emissions units with uncontrolled emissions of any pollutant regulated under subpart C of 40 

CFR Part 68 if those emissions are below the accidental release threshold levels set forth at 40 

CFR 68.130 or 1,000 pounds per year, whichever is less. 

C. Insignificant activities include emissions units, other than those listed in subsection A or B of this 

section, with the following sizes or production rates: 

1. Internal combustion engines used for standby service, including compressors and pumps used 

for emergency replacement and portable generators, as follows: 

a. Engines burning diesel fuel (maximum 0.5% sulfur) with 259,000 Btu per hour input or less; 

b. Engines burning gasoline with 18,200 Btu per hour input or less. 

2. Fuel burning equipment or combustion units with heat input levels less than: 

a. 10 million Btu per hour rated input, using natural gas; 

b. 1 million Btu per hour rated input, using distillate oil (maximum 0.5% sulfur). 

3. Reservoirs and storage tanks for lubricant or used oil with a capacity of less than 1,000 gallons. 

4. Internal combustion powered generators used at a facility only when power is unavailable to the 

facility from the utility as follows: 

a. Diesel-fueled turbine emergency generators of 780 horsepower or less; 

b. Diesel-fueled reciprocating emergency generators of 645 horsepower or less; 

c. Natural gas-fueled turbine emergency generators of 1,240 horsepower or less; 

d. Natural gas-fueled reciprocating emergency generators of 840 horsepower or less; 

e. Dual-fueled reciprocating emergency generators of 840 horsepower or less. 

Statutory Authority 

§ 10.1-1308 of the Code of Virginia. 

Historical Notes 
Derived from Virginia Register Volume 12, Issue 25, eff. October 15, 1996; amended, Virginia Register 

Volume 17, Issue 4, eff. Jan. 1, 2001.