2004-02-02_REVISION - m1980183

• Permit No: m1980183
• IBM Index Class Name: Revision
• Doc Date: 2/2/2004
• Doc Name: Climate
• From: JR Engineering
• To: DMG
• Type & Sequence: AM1
• Media Type: M
• Archive: No

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AIR QUALITY IMPACT FROM BRANNAN PIT 29
I. INTRODUCTION
The Brannan Sand and Gravel Company plans to
mine and process sand and gravel at its Pit 29 which
is located east of Old Brighton Road in the north half
of the section north of the section in which
Henderson, Colorado is located. The property extends
east to Nome. It is a wet area on the east side of the
Platte River.
Brannan plans to mine 3000 tons per day during 167
spring, summer and autumn days. Thus, the annual
total production will be 500,000 tons. Overburden
will be used to build a berm around the area to shield it
from view from outside and to shield outside areas
from the noise of the operation. These berms will be
revegetated as rapidly as possible to reduce wind
erosion from both the berms and the protected area
within.
Operations at the pit will create dust, some of which
will remain airborne long enugh to be carried by the
wind to adjacent areas. The dust emissions to be
expected have been calculated and are reported
here.
II. EMISSIONS
The only significant pollutant emission expected
from operation of Pit 29 is particulate matter.
Emissions have been calculated using factors
approved by the Colorado State Air Pollution Control
Division. The operations to which the factors have
been applied are: 1) removal of overburden, 2) mining
and processing the sand and gravel, and 3) vehicle
traffic. Also, emissions from wind erosion of
disturbed areas have been calculated. Each of these
is discussed briefly in this section.
A. REMOVAL OF OVERBURDEN
It is anticipated that 20 acres of land will be
mined each year. The topsoil is 1 .5 to 2 feet deep.
Additional overburden is 2 to 2.5 feet deep. In the
calculations a total overburden depth of 4.0 ft
has been used. The overburden will be rernoved
by scrapers and placed in berms around the
property or used to reclaim mined areas.
Disturbed areas will be revegetated as rapidly as
possible so that no more than 20 acres will be
subject to wind erosion at any time.
Emissions from the removal of overburden were
calculated by using a factor of 16 pounds of
particulate matter per hour of scraper operation.
The following formula applies
E AXdX1 DXEF
27 C S 2000
in which E is emission in tons; A is the area (A
43,500 It 2 X 20 X 43,600 ft2 );
d is the depth of overburden
in feet; C is the capacity of the scrapers in cubic
yards; D is the round trip distance in miles
traveled with each load; S is the scraper speed in
miles /hour, and EF is the emissions factor in Ibs
per scraper hour.
E 872,000 X 4.4 X 1 X 0.25 X 16
27 25 3.75 2000
E 2.8 tons /year
B. MINING AND PROCESSING
The emissions factor for mining and processing
sand and gravel is 0.1 lb/ton of material
processed. This yields an annual emission iof
E 0.1 x 500,000 25.0 tons /year
2000
C. VEHICLE TRAVEL
The emissions factor for vehicle travel for speeds
OF- cnA'TION
METHOD OF PERCENT EMISSIONS
under 30 miles per hour is given by the following
CONTROL CONTROL FACTOR
6
formula:
Overburden Removal None 0 16 lb/hr
Heaviest precipitation occurs during the spring and
EF 1.81s S 2 365 -w) N
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summer months of April through June.
( ) (
30 365 X 4
Vehicle Travel Wetting 50 189.1 lb/day
a
Disturbed Area
Erosion None 0 0.33 T /acre yr
c�
a ..
U
in which EF is the emissions factor in pounds per
F F
mile traveled; s is the silt content in percent of
N
1.10 1.00 .70 .40 14.60
the surface traveled; S is the vehicle speed in
a
miles per hour; w is the average number of days
EMISSIONS
per year with 0.01 in or more of precipitation;
POTENTIAL CONTROLLED HOURLY RATE" ANNUAL
WINDS
and N is the number of wheels on the vehicle.
(T /Y) (T /Y) (g; s) (g /s)
The predominant wind direction at Pit 29 is from the
With s 10 and w 100, the formula reduces to
c(•
EF 1.63 X 10 4 S2N
_
near 7 miles per hour (mph). Strongest winds
r
25.0 4.72 0.72
15.8 7.9
s
ca
S
1.49 0.23
direction for wind speeds 25 mph or more is from the
DAILY VEHICULAR EMISSIONS
6.6 6.6 1.12 0.19
northwest. The direction of daytime winds from 8
Vehicle Speed Wheels EF
Dist. Emissions
TOTAL 50.2 42.3 7.86 1.22
a.m. through 5 p.m, is highly variable. The direction
Type (m /h) (N) (1 b /mi)
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Cat Loader 0.5 4 1.6 X 10 -3
-2
EROSION 35.7 6.74
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16 2.6 X 10
4 -3
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Tractor Trailer 10 18 2.94
Pickup 10 4 0.65
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AIR QUALITY IMPACT FROM BRANNAN PIT 29
I. INTRODUCTION
The Brannan Sand and Gravel Company plans to
mine and process sand and gravel at its Pit 29 which
is located east of Old Brighton Road in the north half
of the section north of the section in which
Henderson, Colorado is located. The property extends
east to Nome. It is a wet area on the east side of the
Platte River.
Brannan plans to mine 3000 tons per day during 167
spring, summer and autumn days. Thus, the annual
total production will be 500,000 tons. Overburden
will be used to build a berm around the area to shield it
from view from outside and to shield outside areas
from the noise of the operation. These berms will be
revegetated as rapidly as possible to reduce wind
erosion from both the berms and the protected area
within.
Operations at the pit will create dust, some of which
will remain airborne long enugh to be carried by the
wind to adjacent areas. The dust emissions to be
expected have been calculated and are reported
here.
II. EMISSIONS
The only significant pollutant emission expected
from operation of Pit 29 is particulate matter.
Emissions have been calculated using factors
approved by the Colorado State Air Pollution Control
Division. The operations to which the factors have
been applied are: 1) removal of overburden, 2) mining
and processing the sand and gravel, and 3) vehicle
traffic. Also, emissions from wind erosion of
disturbed areas have been calculated. Each of these
is discussed briefly in this section.
A. REMOVAL OF OVERBURDEN
It is anticipated that 20 acres of land will be
mined each year. The topsoil is 1 .5 to 2 feet deep.
Additional overburden is 2 to 2.5 feet deep. In the
calculations a total overburden depth of 4.0 ft
has been used. The overburden will be rernoved
by scrapers and placed in berms around the
property or used to reclaim mined areas.
Disturbed areas will be revegetated as rapidly as
possible so that no more than 20 acres will be
subject to wind erosion at any time.
Emissions from the removal of overburden were
calculated by using a factor of 16 pounds of
particulate matter per hour of scraper operation.
The following formula applies
E AXdX1 DXEF
27 C S 2000
in which E is emission in tons; A is the area (A
43,500 It 2 X 20 X 43,600 ft2 );
d is the depth of overburden
in feet; C is the capacity of the scrapers in cubic
yards; D is the round trip distance in miles
traveled with each load; S is the scraper speed in
miles /hour, and EF is the emissions factor in Ibs
per scraper hour.
E 872,000 X 4.4 X 1 X 0.25 X 16
27 25 3.75 2000
E 2.8 tons /year
B. MINING AND PROCESSING
The emissions factor for mining and processing
sand and gravel is 0.1 lb/ton of material
processed. This yields an annual emission iof
E 0.1 x 500,000 25.0 tons /year
2000
C. VEHICLE TRAVEL
The emissions factor for vehicle travel for speeds
OF- cnA'TION
METHOD OF PERCENT EMISSIONS
under 30 miles per hour is given by the following
CONTROL CONTROL FACTOR
ESTIMATED PRECIPITATION
formula:
Overburden Removal None 0 16 lb/hr
Heaviest precipitation occurs during the spring and
EF 1.81s S 2 365 -w) N
Mining and Processing None 0 0.1 lb/ton
summer months of April through June.
( ) (
30 365 X 4
Vehicle Travel Wetting 50 189.1 lb/day
Jan. Feb. Mar. Apr. May June July Aug.
Disturbed Area
Erosion None 0 0.33 T /acre yr
.60 .70 1.10 1.80 2.50 1.80 1.70 1.20
in which EF is the emissions factor in pounds per
Sept. Oct. Nov. Dec. Annual Total
mile traveled; s is the silt content in percent of
1.10 1.00 .70 .40 14.60
the surface traveled; S is the vehicle speed in
miles per hour; w is the average number of days
EMISSIONS
per year with 0.01 in or more of precipitation;
POTENTIAL CONTROLLED HOURLY RATE" ANNUAL
WINDS
and N is the number of wheels on the vehicle.
(T /Y) (T /Y) (g; s) (g /s)
The predominant wind direction at Pit 29 is from the
With s 10 and w 100, the formula reduces to
south- southwest. The annual mean wind speed is
EF 1.63 X 10 4 S2N
2.8 2.8 0.53 0.00
25.0
near 7 miles per hour (mph). Strongest winds
25.0 4.72 0.72
15.8 7.9
typically occur in March or April. The predominant
1.49 0.23
direction for wind speeds 25 mph or more is from the
DAILY VEHICULAR EMISSIONS
6.6 6.6 1.12 0.19
northwest. The direction of daytime winds from 8
Vehicle Speed Wheels EF
Dist. Emissions
TOTAL 50.2 42.3 7.86 1.22
a.m. through 5 p.m, is highly variable. The direction
Type (m /h) (N) (1 b /mi)
(mi /day) (tb /day)
TOTAL W/O
arc of greatest frequency for daytime winds is in the
Cat Loader 0.5 4 1.6 X 10 -3
-2
EROSION 35.7 6.74
quadrant from north through east.
D -8 Cat 0.25 4* 4.08 X 10 -4
16 2.6 X 10
4 -3
Tractor Trailer 10 18 2.94
Pickup 10 4 0.65
2.4 X 10
60 176.4.
*The hourly rate is the rate at which emissions occur
LOREN W. CROW
Certified
Grease Truck 5 6 0.24
2.5
during working hours. For calculating maximum
9 g g
Consulting Meteorologist
Mechanics Truck 10 4 0.65
0.6
0.5 0.3
(worst case) 24 -hour concentrations in the vicinity of
Water Truck 10 10 1.63
6 9.8
the site; hourly rates are assumed to exist for eight
TOTAL UNCONTROLLED
hours, except that the disturbed area rate is assumed
TRAFFIC AND ACCESS ANALYSIS
1891
to exist for 24 hours.
ACCESS ROADWAYS
*The caterpillar but it
All vehicular access is planned to be limited to one
travels so slowly that emissions are very small.
sow that emirs ons are very small.
111. APPLICABLE REGULATIONS
Nome Street driveway location which will be
Since the vehicles are to operate 167 days per
Potential emissions will be 50.2 tons per year. This is
relocated from time to time during the phased
year, the annual production is 15.8 tons.
well under the 100 tons per year specified in Section
development of the project. Nome is a two -lane,
D. DISTURBED AREA EROSION
3.IV.D.4. of the Colorado Air Quality Control
paved roadway having limited north /south
Regulations. Hence that Section applies. It states
continuity between US 85 and CR 31 at 136th
Wind erosion from exposed areas is given by the
Avenue. Present traffic activity on Nome is minimal
universal soil loss equation
The Commission may only direct Nu' Division to
due to the low intensity of land uses which it serves.
EF aIKCL'V' (tons /acre year).
slue an Emission Permit when the Commission
Southbound Nome Street traffic is controlled by a
finds that one of the following conditions are
Stop sign at US 85.
in which a is the portion of erosion losses that
met:
can measured as suspended particles; I is soil
US 85, which will serve as the project's access route
ib
erodibility in tons per acre year; K is a surface
That in the case of sources with potential
to and from the southwest, is a major divided four -
roughness
roughness factor which varies from 0.5 for
(uncontrolled) emissions of less than one
lane highway w +th a p�cted .;pp of 55 miles
deeply furrowed
p y ground to 1.O for a smooth
hundred (100) tons per year of a single air
per hour. Based on recent counts taken by the
surface; C is a climatic factor which has a value
contaminant or which are otherwise exempt
Colorado Division of Highways, about 15,500
of 0.5 for this site; L' is an unsheltered width
from the requirements of Section IV.D.3.c. and
vehicles travel along US 85 in the vicinity of the site,
factor which ranges from 0.7 for a disturbed area
where the emissions would interfere with the
No other nearby roadways will be affected by the Pit
1000 feet wide to 1.0 for an area 2000 feetwide,
attainment or maintenance of national
29 project.
and V' is a vegetative cover factor which ranges
ambient air quality standards (i.e., cause or
TRAFFIC GENERATION AND DISTRIBUTION
from 0.0 for good, dense cover to 1 .Ofor no cover.
contribute to ambient concentrations which
For Pit 29, the equation is
exceed a national ambient air quality standard
The generation of traffic by Pit 29 should be
in designated non - attainment areas), the
considered in a different light than a typical industrial
EF 0.025 X 38 X 1.0 X 0.5 X 0.7 X 1.0 0.33
applicant will meet all other applicable
operation. First of all, very few employees are
tons /acre year
standards and regulations of the Commission
involved in the gravel mining process and traffic
For 20 acres, this yields 6.6 tons per year of
and that despite the emissions which will
activity is uniformly distributed throughout the work
particulate emissions.
result from the proposed new source or
day. "Peak hour" traffic generation is therefore
E. EMISSION CONTROLS
modified source, reasonable further progress
virtually non - existent. Secondly, traffic consists of a
In a sand and gravel pit where materials are wet,
toward the attainment of the national ambient
relatively small number of large vehicles, and such
dust is controlled by the natural wetness of the
air quality standards is not impaired.
activity is very dependent on factors such as weather
material. The emissions factor for mining and
It is also pertinent that controlled emissions are 42.3
and construction scheduling. Because of these
characteristics,
processing takes account of this. Therefore,
tons /year, 640 Ibs /day, and 62 Ibs /hour. The daily
the operation will have only minimal
traffic impact.
although spray bars will be used on the
and hourly rates occur during periods when wind
The Pit 29 operation is expected to
produce an estimated 500,000 tons of material per
processing equipment, no control of the mining
erosion is ocurring. Therefore, they are maximum
year with a maximum daily production of 3000 tons.
or processing is assumed in calculating on-
g
values. With these values, Section 3.IV.D.5.B.(vii)
This is equivalent to a
q pproximately 125 truck loads of
trolled erissions.
exempts the operation from requiring offsets,
material on a maximum day.
AMBIENT ANALYSIS, INC.
The routing of Pit 29 vehicles dictates that all gravel
The formula for calculating vehicular emissions
Al Morris
truck travel will be oriented to and from the south
is based on a dry surface. Consequently,
along Nome Street and US 85. The only access
controls, both natural and sprinkling, are
CLIMATIC INFORMATION RELATED TO PIT 29
oriented to the north could be an occasional service
assumed in calculating emissions.
Pit 29 is located in Adams County on the east
or employee vehicle.
The emissions factor for removal of topsoil also is
shoulder of the Platte River in the vicinity of 138th
CONCLUSIONS
based on working in soil that is naturally moist
Avenue and Highway 1 -76. It is in a zone of semi -arid
but not wet. The overburden at Pit 29 will
climate. Extreme warm weather in the summer
The Pit 29 project will generate a maximum of 125
probably be more moistthanthe soil on which the
months produces daytime maxima temperatures in
entering and 125 exiting vehicles on a maximum day
factor was based, but it is assumed that no
the 90's. On a few morning in the winter, minima
of production. All traffic will be destined to and from
controls will be used. Hence potential and
temperatures go below 0 "F.
the southwest via Nome Street and US 85. Both of
controlled emissions are equal.
TEMPERATURES
the affected roadways and their related traffic
Much of the disturbed area will be wet and not
controls are more than adequate to accommodate
Mean monthly temperatures, based on comparative
this small increase in traffic activity.
Subject to erosion. Also, theexposed overburden
historical records from Denver and Brighton, are as
will have a rough surface. Nonetheless, no
follows:
LEIGH, SCOTT & CLEARY, INC.
controls are assumed in calculating controlled
Consulting Traffic Engineers
emissions from wind erosion.
Jan. Feb. Mar. Apr. May June July Aug.
F.
28.4 31.8 36.5 47.0 56.5 65.5 72.0 70.6
AIR QUALITY, CLIMATOLOGY,
SUMMARY
Sept. Oct. Nov. Dec.
Calculated emissions from Pit 29 are
61.8 51.0 38.4 31.1
& TRAFFIC ANALYSIS TEXT
summarized in the table on the following page.
Paae 2 1 of 2A