WSP11863

• File Number: 8200.750
• Description: San Juan River General
• State: CO
• Basin: San Juan/Dolores
• Water Division: 7
• Date: 8/1/1986
• Author: USFS
• Title: Wolf Creek Valley Ski Area - Revised Draft - Environmental Impact Statement - San Juan National Forest - 1986 - Chapter IV to end
• Water Supply Pro - Doc Type: Report/Study

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for meteorological conditions on January 12, 1984. This same
day is used to estiJrate maximum one hour and eight hour
carbon monoxide impacts, since the highest one hour and eight
hour average TSP concentration are also calculated by the
model on this day. Fireplaces and woodstwes account for the
majority of the CO emissions and therefore, the diurnal (l)
emissions profile closely follows the diurnal TSP emissions
profile. Thus, the highest CO impact estiJrates provided by
the Box Model should occur on the same day as the highest TSP
impact. Table IV-ll summarizes the maximum one hour and
eight hour carbon monoxide impacts at Wolf Creek Valley. The
highest one hour and eight hour impacts are estimated in BOx
3 at 5495 ug/m per cubic foot and 3,070 ug/m per cubic foot,
respectively. Representative background CO levels (Latimer
et aI, 1983) of 2,500 ug/rn per cubic foot (one hour) and
1,500 ug/m per cubic foot (eight hour) added to these
estimates to result in ambient (l) concentrations for
comparison with Colorado and tational ambient air quality
standards. The ambient (l) concentration estimates of 7,995
ug/rn per cubic foot for the one !lour average and 4,570 ug/m
per cubic foot for t!le eight hour average are well below the
ambient standard of 40,000 ug/m per cubic foot (one hour) and
10,000 ug/m per cubic foot (eight hour) (see Table 111-13) .

TAf[,E IV-ll

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Nr VT.F rRRMr UlJ.r,RV

Box
I
2
3
4

.1
Carbon Ibnoxide Concentrations (ug/m )
1 Hour 8 Hour
219 47
4959 2897
5494 3070
4717 2480

(3) Visual Air Ouality

The impact of fine particulate emissions on the visual air
quality of Wolf Creek Valley is of concern due to the
excellent visibility of the area, the long scenic vistas from
the surrounding mountains and the importance of clear air to
the overall liveability and enjoyment of this area.
Woodstoves and fireplaces emit fine particulates which cause
light to be scattered and can result in a visible haze and a
reduction in visual range*. In this case, pa~ticulate levels
in the valley during early morning or late afternoon (when
concentrations are expected to be at their highest levels
during daylight hours) could result in a visible haze layer.

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I
I

*

Visual range is the farthest distance that a black
object is perceptible against the horizon sky.

187