_PERMIT FILE - M1981302 ‎(34)‎

• Permit No: M1981302
• IBM Index Class Name: Permit File
• Doc Name: FIGURE G-2 MAXIMUM ESTIMATED DUST EMISSIONS FROM GRAVEL PRODUCTIONS AT DEEPE FARM PROJECT
• Media Type: D
• Archive: No

Air Quality Impact
An estimate of the maximum expected concentration of air-
borne particulate has been derived by standard air quality
modeling methodsl. It has been assumed that most emissions
on any given day will originate within a 100 m (328 ft. )
square area between ground level and 20 m height. For
typical daytime temperature and atmospheric stability, and
a 4 m/sec. (9 mph) wind speed, the following 24-hour average
concentrations were calculated for the indicated downwind
distances .
Distance Distance 24-hr. Average Concentration
(meters) (feet) (micrograms/cubic meter)
200 650 45
• 400 1310 27
700 2300 15
1000 3280 10
The Federal Secondary 24-hour Standard for particulate
matter is 150 pg/m3 (which is also the State of Colorado
Standard) . The 200 m distance is a typical distance from
mining operations to the property boundary; at this dis-
tance expected maximum 24-hour concentrations are predicted
to be less than one-third of the most stringent standard.
•
1Turner, D.B. , 1969 : Workbook of Atmospheric Dispersion
Estimates, U.S. Environmental Protection Agency, Research
Triangle Park, N.C.
C. G-12