5 Colo. Code Regs. § 1001-11-B
TABLE I EXAMPLE BURNS Estimated to Potentially Produce 10 Tons of PM10 Emissions
FUEL TYPE | SIZE OF BURN | FUEL LOADING ASSUMED | FUEL CONSUMPTION ASSUMED (%) | EMISSION FACTOR (pounds/ton) |
Grass | 575 acres | 2 tons/acre | 87 | 20 |
Sagebrush | 191 acres | 5 tons/acre | 70 | 30 |
Oakbrush or Aspen | 556 acres | 4 tons/acre | 50 | 18 |
Pine/Conifer | 23 acres | 30 tons/acre | 48 | 60 |
Pinon/Juniper | 476 acres | 3 tons/acre | 59 | 24 |
Piled Slash | 144,000 ft3 | 38 pounds/ ft3 | 92 | 8 |
Example Calculations:
Example 1
A grass burn of 575 acres that is estimated to have a fuel loading of 2 tons per acre and 98% of the acreage burned (black acreage) is estimated to produce:
([(575 acres x .98) x 2 tons/acre] x 20 pounds/ton)÷ 2000 pounds/ton=11.27 tons of PM10
A landowner/manager completing this burn is a "significant user of prescribed fire" as defined in Regulation Number 9.
Example 2
A manager is proposing to treat 140 acres of mixed conifer in this calendar year. It is estimated the fuel loading is 5 tons per acre and 48% of the area is to be burned. This burn is estimated to produce the following particulate matter emissions:
140 acres x 48% fuel consumption=67.2 black acres
67.2 acres x 5 tons/acre=312 tons of fuel consumed
(312 tons x 60 pounds PM10/ton)÷ 2000 pounds/ton=9.36 tons of PM10
The PM10 emissions are below 10 tons. Based on this single burn, the manager is not defined as a "significant user of prescribed fire" in Regulation Number 9. If additional projects are to be completed in the same calendar year, the manager may be defined as a "significant user of prescribed fire" due to cumulative total PM10 emissions exceeding 10 tons.
TABLE II SOURCES OF INFORMATION/DATA USED IN TABLE I
FUEL TYPE | REFERENCE | REFERENCE |
FUEL LOADING | EMISSION FACTOR | |
Grass | Aids to Determining Fuel Models for Estimating Fire Behavior, US Forest Service, 1982 and historical activity data | AP-42, EPA, 1996, Rocky Mountain Grasslands |
Sagebrush | Average of historical activity data reported to the Division | US Forest Service, Fire and Air Research Station memo to the Division, 1990 |
Oakbrush or Aspen | Average of historical activity data reported to the Division | AP-42, EPA, 1996, Pacific SW Chaparral |
Pine/Conifer | AP-42, EPA, 1996, Wildfires and Prescribed Burning, Rocky Mountain. Avg. | AP-42, EPA, 1996, Rocky Mountain Underburning Pine |
Pinon/Juniper | Average of historical activity data reported to the Division | AP-42, EPA, 1996, Pacific SW Pinon/Juniper |
Piled Slash | Guidelines for Estimating Volume, Biomass, and Smoke Production for Piled Slash, US Forest Service, 1996 | AP-42, EPA, 1996, Rocky Mountain Logging Slash |
5 CCR 1001-11-B