good smoke dispersion. It is important that fire not be able to spread and 

 smolder between piles as fire that smolders in the duff has the potential to 

 produce smoke over a longer period of time with a higher rate of emissions 

 per pound of fuel than fuel that bums with flaming combustion. Due to the 

 potential impact that this amount of smoke could cause on air quality it would 

 be vital to be very selective in choosing a day to ignite the bum. Strong east 

 winds would be ideal. This would disperse smoke west to very sparsely 

 populated areas in Westem Montana and North Idaho. West to northwest 

 winds would also be acceptable, as this would disperse the smoke to the 

 Miller Creek area. South to southwest winds would send the smoke directly 

 into the Missoula Valley. North winds would send smoke into the Bitterroot 

 Valley. Both the Missoula and Bitterroot Valleys are populated areas where 

 impacts from smoke should be minimized. Buming would only be conducted 

 under good to excellent smoke dispersion conditions. Piles would be burned 

 as dry as possible and would be kept free of dirt. DNRC would work closely 

 with the Monitoring Unit of the Montana/Idaho Airshed Group and obtain 

 special smoke dispersion forecasts in order to bum only on ideal days. Only 

 a handful of days each year meet the conditions that are necessary to conduct 

 this bum with the desire results and not have adverse air quality impacts. This 

 may require that slash remain unbumed in the unit for longer than normal 

 until the right conditions are present. With proper smoke management 

 applied, impacts to air quality should be minor and short in duration. 



4.3.5.3 Cumulative Effects of Alternative B: Harvest 



Smoke resulting from this project would have a cumulative effect with other 

 prescribed bums being conducted in the region as well as with pollutants 

 produced from other sources. Smoke produced in Montana and Idaho is 

 regulated by the smoke monitoring unit, and its cumulative impact is 

 considered in issuing buming restrictions. Industrial, agricultural and 

 vehicular sources of particulate will also be producing pollutants while 

 buming is ongoing. With attention to buming under only ideal conditions, the 

 projects cumulative impact to air quality should be minor and of short 

 duration. 



4.3.6 Noxious Weeds (Issue #6) 



4.3.6.1 Alternative A: Deferred Harvest (No Action) - Direct and 

 Indirect Effects 



Under Altemative A: Deferred Harvest (No Action), weed seed is expected to 

 spread by vehicle traffic, wind and animal dispersion into the project area, 

 which would result in competition with native species trying to establish in 

 any areas where the vegetation and soil is disturbed. Bio-control efforts by the 

 State of Montana to reduce the presence of knapweed and leafy spurge would 

 continue. 



Deadman Gulch Timber Sale Environmental Assessment 4-7 



