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E-M:/ pollution from snowmobiles

Enviro-Mich message from doug welker <dwelker@up.net>

Subject: NPS Morning Report - Wednesday, October 27, 1999
Author:  Bill Halainen at NP-DEWA
Date:    10/27/1999 9:22 AM

                            NATIONAL PARK SERVICE
                               MORNING REPORT
To:         All National Park Service Areas and Offices
From:       Division of Ranger Activities, Washington Office
Day/Date:   Wednesday, October 27, 1999

The following is an excerpt from that this report:

Yellowstone NP (WY) - Snowmobile Air Pollution Study
A report has been completed by the NPS Air Resources Division that details 
concerns over air quality stemming from snowmobile usage in national parks 
across the United States.  The report is a compilation of studies completed 
by a number of organizations, primarily in Yellowstone, including the Montana 
Department of Environmental Quality, the Southwest Research Institute, the 
University of Denver, the U.S. Geological Services, and the NPS.  The 
studies, conducted over a four-year period, confirm the park's concerns over 
the health effects of snowmobile emissions on park visitors and employees and 
environmental impacts on the Yellowstone ecosystem.  Motor vehicles emit 
several pollutants that EPA classifies as known or probable human 
carcinogens, such as benzene and hydrocarbons.  The EPA estimates that mobile 
sources account for as much as half of all cancers attributed to outdoor 
sources of air toxics.  For a number of reasons, snowmobiles, which have 
two-stroke engines, are much more polluting than automobiles, which have 
four-stroke engines:
o     Up to one-third of the fuel delivered to the engine goes straight
      through without being burned.  
o     The lubricating oil is used once and is then expelled as part of the
o     The combustion process results in high emissions of air pollutants,
      including hydrocarbons or volatile organic compounds, nitrogen oxides, 
      particulate matter, and carbon monoxide.  When compared to automobile 
      emissions, snowmobiles can emit 100 times more carbon monoxide and 300 
      times more hydrocarbons.
Although the number of snowmobiles that enter the park during a three-month 
time period is much lower than the number of automobiles that enter the park 
year-round (on average, one snowmobile for every 16 vehicles), snowmobile 
emissions dominate the total annual emissions for carbon monoxide (78 
percent) and hydrocarbons (94 percent) when compared to other mobile sources, 
such as cars and RVs.  On a peak day (2,000 snowmobiles entering the park), 
32 tons of hydrocarbons and 88 tons of carbon monoxide can be emitted. 
During a single winter season, as much as 1,200 tons of hydrocarbons and 
2,400 tons of carbon monoxide can be emitted.  The study also found that 
snowmobiles contribute approximately three percent of the annual nitrogen 
oxide emissions and 37 percent of the particulate matter emissions.  One 
study conducted in 1996 showed that concentrations of ammonium and sulfate in 
snow positively correlated with snowmobile and oversnow vehicle use, as 
levels of these pollutants generally declined a short distance from 
snowpacked roads.  It was noted that there is a potential for these 
pollutants to affect nearby surface waters during snowmelt and spring runoff. 
A study was conducted this year at the park's West Entrance to monitor 
personal exposure for particulate matter and volatile organic compounds.  The 
maximum time-weighted concentration of particulate matter on the 13th and 
14th of February showed concentrations of 116 and 122 particulate matter, 
respectively; the National Ambient Air Quality Standard for acceptable 
particulate matter concentrations is 60.  To put this in perspective, the 
maximum 24-hour particulate matter concentration in the Los Angeles suburb of 
Azusa in 1997 was 68.  Under the Clean Air Act, the Service has an 
affirmative responsibility to protect air quality related values - including 
visibility - from the adverse effects of air pollution in areas that are 
designated as "Class I."  As directed by Congress, Class I areas are to be 
afforded the greatest degree of air quality protection and are permitted to 
have only very small amounts of air quality deterioration from new or 
modified major stationary sources.  Notwithstanding an area's designation 
under the Clean Air Act, NPS areas that have documented adverse effects due 
to air pollution must seek to mitigate or eliminate these impacts.  Some 
steps have already been taken in the park to address these problems.  The 
park uses biodegradable lubricants gasohol (an oxygenated fuel made by 
ethanol splash-blended with regular or premium gasoline; this fuel can reduce 
carbon monoxide emissions by 20-25 percent in automobiles) in its 
administrative fleet, and the state of Montana has directed that its 
administrative snowmobiles use low smoke or biodegradable lubricants. 
Longer-term goals for reducing snowmobile emissions are being addressed in 
the winter use plan/draft environmental impact statement for Yellowstone and 
Grand Teton National Parks and John D. Rockefeller, Jr., Memorial Parkway. 
Those documents are out for public review until December 1st.  [PAO, YELL]

			-doug welker-

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