HomeMy WebLinkAboutFile Documents.33 MINING STOCK PKWY.0093-2020-BRES (13)20-1653 - Exhibit F
08/26/2020
08/26/2020
Confirm that HP
Geotech has
reviewed the final
plans. Is additional
field exploration
needed? Will those
results impact the
design?
08/26/2020
08/26/2020
08/26/2020
Are excavation
stabilization plans
required for
construction? If so,
provide COA
Engineering Standard
compliant plans for
review.
08/26/2020
08/26/2020
08/26/2020
Were site specific
perc tests performed
at infiltration locations
in the final design?
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
Soil Report
Burlingame Ranch Phase II
Pitkin County, Colorado
prepared for:
City of Aspen
c/o John Laatsch, Capital Assets Department, 4155 Rio Grande Place, Aspen, CO 81611
prepared by:
Western Ecological Resource, Inc.
711 Walnut Street, Boulder, CO 80302
September 2010
08/26/2020
Acknowledgement
Topsoil Inventory, Mapping and Evaluation by:
David Buscher
Buscher Soil and Environmental Consulting, Inc.
PO Box 156
Rollinsville, CO 80474
08/26/2020
Table of Contents
Number / Section Page
1.0 Introduction..........................................................................................................................1
2.0 Environmental Setting ...........................................................................................................1
3.0 Methods................................................................................................................................1
4.0 Assumptions..........................................................................................................................2
5.0 Soils of the Project Site..........................................................................................................2
5.1 Topsoil Thickness and Volume ..........................................................................................3
5.1.1 Unit 1 - 20” Topsoil ...................................................................................................3
5.1.2 Unit 2 - 17” Topsoil ....................................................................................................3
5.1.3 Unit 3 - 10” Topsoil ....................................................................................................5
5.1.4 Unit 4 – Disturbed with 4” Topsoil..............................................................................5
5.1.5 Unit 5 - Rocky Ridges with No Suitable Topsoil...........................................................5
5.1.6 Unit 6 - Disturbed Lands .............................................................................................5
5.2 Chemical Characteristics and Suitability of the Soils...........................................................6
6.0 Recommendations.................................................................................................................8
6.1 Site Preparation .................................................................................................................8
6.2 Soil Salvage.......................................................................................................................8
6.3 Soil Screening....................................................................................................................8
6.4 Topsoil Storage..................................................................................................................8
6.5 Soil Compaction................................................................................................................8
6.6 Topsoil, Fertilizer, Woody Mulch & Mycorrhizae Application............................................8
7.0 Conclusions..........................................................................................................................9
8.0 Disclaimer ............................................................................................................................9
9.0 References ..........................................................................................................................10
10.0 Figures..............................................................................................................................11
Appendix A. Brief Soil Descriptions...........................................................................................14
Appendix B. Soil Laboratory Results..........................................................................................17
08/26/2020
List of Figures
Number / Section Page
Figure 1. Project Location Map..................................................................................................12
Figure 2. Soil Map.....................................................................................................................13
List of Tables
Number / Title Page
Table 1. Topsoil Stripping Areas, Depths & Volumes...................................................................4
Table 2. Topsoil Criteria for Establishment of Bluegrass or Fescue Lawns .....................................7
08/26/2020
1
1.0 Introduction
The City of Aspen has plans to construct Phase II of the Burlingame Ranch affordable housing
development on a 16.2 acre site located at the base of Deer Hill, approximately 1.5 miles
northwest of Aspen, Colorado. The project site is located east of U. S. Highway 82 and just
west of the Roaring Fork River. Specifically, the site is located in Section 4 of Township 10
South and Range 85 West in Pitkin County, Colorado (Figure 1).
To aid in project planning, the City of Aspen contracted Western Ecological Resource, Inc. to
map and describe the topsoil on the project site, evaluate its suitability for establishing a
bluegrass or fescue lawn, and to provide recommendations for soil handling and reclamation.
This work was completed by David Buscher, a certified professional soil scientist with 24
years of professional experience.
This report describes the findings of the soil investigation and presents thicknesses and volume
of suitable topsoil at the site, contains a topsoil thickness map and provides recommendations
and procedures for topsoil and site restoration.
2.0 Environmental Setting
The 16.2 acre Phase II project site consists of gently sloping to moderately steep backslopes
and gently sloping ridge tops and swales with a shrub-dominated plant community. The site
adjoins the completed Phase I housing development to the east, and there are two disturbed
areas totaling approximately 1.3 acres used for rock and landscape material storage.
The surficial geology consists of glacial drift and possibly some more recent alluvium. The
surface generally contains coarse fragments of 5 to 10 percent gravel (2mm to 3 inches in
diameter), 1 to 5 percent cobbles (3 to 10 inch diameter) and 1 to 5 percent stones and
boulders (greater than 10 inch diameter). The surfaces of low lying ridge tops, however,
contain up to 40 to 50 percent coarse fragments. Vegetation of the site consists of shrubs,
grasses and forbs, with big sagebrush (Artemisia tridentata), serviceberry (Amelanchier
alnifolia), rabbitbrush (Chrysothamnus sp.), bitterbrush (Purshia tridentata), snowberry
(Symphoricarpos rotundifolius), and Gambel oak (Quercus gambelii) comprising most of the
shrub community. The average annual precipitation is 16 to 19 inches and the growing
season is 75 to 95 days (USDA-SCS, 1992).
3.0 Methods
Mr. Buscher mapped topsoil thickness at the site and described 29 topsoils in shallow, hand-
auger and shovel excavated pits and at two observation points on August 30 and 31, 2010.
To assess the chemical and physical characteristics of the topsoil, he collected five topsoil
samples that were submitted to Colorado Analytical Laboratory in Brighton, Colorado for
agronomic testing. Seven additional topsoil samples collected from geotechnical borings
completed by HP Geotech were also included in the testing and analysis.
Based on field investigations and the results from geotechnical studies, six topsoil map units
were identified on the project site. These map units represent different topsoil depths and
were delineated based on best professional judgment and onsite measurements. To estimate
the topsoil thickness of a given area, several soil observations were made and the measured
topsoil thicknesses were averaged.
08/26/2020
2
4.0 Assumptions
Due to the glacial origin of the soils, spatially there is an erratic distribution of rocks within the
soil profile, and consequently several assumptions needed to be made in order to delineate
topsoil thickness. These assumptions include the following:
• The actual thickness of topsoil in a specific area may vary by several inches or more
than the average thickness calculated for that area.
• Based on observation of an existing open pit and the geotechnical and earthwork
reports, when cobbles were encountered with either a shovel or hand-auger, it was
assumed that below that depth the soil contained a significant amount of large
coarse fragments and would be unsuitable as topsoil.
• In many places there is some potential topsoil (with about 2.5 percent organic
matter) below the depth of significant cobbles, but this soil would require
considerable screening for use as topsoil. This material, however, may have
commercial value as topsoil and could be used off-site.
• Rocky ridges with 40 to 50 percent rocks on the surface were assumed to be
unsuitable as topsoil. Although the upper 10 inches or so is organic-rich, it is very
rocky and would require significant screening. It may, however, have commercial
value as topsoil and could be used off-site.
• Suitable topsoil contains from 10 to 25 percent fine and medium gravel (2mm to
0.75 inches), with a site average of about 17 percent, and 1 to 5 percent cobbles.
• There are scattered stones (10 to 24 inch diameter) and boulders (greater than 24
inch diameter) on the surface that generally make up 0.5 percent of the surface, but
up to 5 percent in places. Some of these rocks will require special handling for
removal.
• We have assumed that there will be a 3 percent loss of topsoil through grubbing of
vegetation, soil handling, stockpiling, and erosion.
5.0 Soils of the Project Site
The Soil Conservation Service (now known as the Natural Resource Conservation Service)
mapped the soils on the site as part of a general soil survey of parts of Eagle, Garfield and
Pitkin counties. Soils at the site are mapped as Uracca, mosit-Mergel complex, extremely
stony (USDA-SCS, 1992). They are deep to bedrock, well drained, and formed in glacial
outwash and alluvium. These soils have about seven inches of topsoil, and below seven
inches are very cobbly. Even though these soils were encountered during the soil
investigation, other soils having thicker topsoil dominate the site.
The remaining portion of this section describes the physical and chemical characteristics of
the topsoils at the site, and presents representative soil profile descriptions for each topsoil
map unit. It also discusses the thickness and volume of suitable topsoil.
Soils at the Phase II site are well drained, very deep to bedrock, and formed in fine-grained to
very coarse glacial material. The soils contain high amounts of large coarse fragments
(cobbles, stones and boulders) below the organic-rich topsoil. As mentioned above, the
topsoil generally contains 10 to 25 percent fine and medium gravel and 1 to 5 percent
cobbles. The topsoils are relatively organic-rich, largely due to the organic inputs from the
abundant shrubs, and to a lesser extent from grasses and forbs.
08/26/2020
3
5.1 Topsoil Thickness and Volume
Four different topsoil thickness units and two miscellaneous units having no topsoil were
described and delineated at the site. These units include: 1) 20 inches of topsoil; 2) 17
inches of topsoil; 3) 10 inches of topsoil; 4) disturbed areas with 4 inches of topsoil; 5)
disturbed lands with no topsoil; and 6) rocky ridges that are too rocky for use as topsoil.
These units are described below with respect to representative soil pits, and their distribution
is illustrated on Figure 2. In addition, Figure 2 shows the locations of 29 soil pits and two
observation points examined by Mr. Buscher, as well as the seven locations sampled from the
geotechnical borings completed by HP Geotech. Appendix A contains brief soil descriptions
of the 29 soil pits and two observation points examined by Mr. Buscher.
The topsoil contains the organic-rich A1, A2 and in places A3 soil horizons (surface horizons
with an accumulation of humified organic matter). These horizons generally have a loam or
silt loam texture with about 15 percent clay and 35 to 50 percent sand (field estimate), contain
about 2.5 to 7 percent organic matter, 10 to 25 percent gravel, and 1 to 5 percent cobbles.
The A1 horizon contains the majority of the plant roots and is undoubtedly the most organic-
rich horizon. In a few areas, a brown B horizon with less organic matter was observed
underlying the A horizons which contained from 15 to 40 percent gravel and 25 percent
cobbles. In other areas there is a transitional AB horizon (horizon with characteristics of both
the A and B horizons) underlying the A horizons. This horizon is relatively organic-rich but
contains a significant amount of rock fragments. The bottom depths of the B and AB horizons
were not reached for this topsoil investigation.
Table 1 lists the topsoil volumes calculated by Alpine Engineering for each map unit. The
table lists the estimated volume for each map unit based on area and depth, as well as an
adjusted volume that assumes a 3 percent reduction due to handling and storage, and a
reduction of 10 percent from the removal of coarse fragments. Specifically, coarse fragments
greater than 0.5 inches would be removed from material to be used in the upper 6 inches, and
coarse fragments greater than 3 inches would be removed from material to be used in the 6 to
12 inch layer.
Alpine Engineering calculated that 13,522 cubic yards of topsoil would be required to re-
spread 12 inches of topsoil over all landscaped and open space areas at the site. As
summarized in Table 1, the site has about 21,496 cubic yards of topsoil assuming a 13% loss
due to storage and handling and the removal of coarse fragments. The excess topsoil volume
of approximately 7,974 cubic yards will likely have a commercial value or could be hauled
off site.
5.1.1 Unit 1 - 20” Topsoil
Pit 20 was described from the southwestern portion of the project area in a gently sloping
swale. The surface in the vicinity of the pit contains about 5 to 10 percent gravel and less
than 1 percent cobbles. This soil has 29 inches of topsoil, more than the average topsoil
thickness for this unit, but otherwise is representative of soils in this unit.
A1 – (0 to 5 inches) very dark brown loam; about 15 percent clay; 10 percent fine and
medium gravel; moderate fine granular structure; soft; non-effervescent.
A2 - (5 to 10 inches) very dark brown loam; about 15 percent clay; 10 percent fine
and medium gravel; moderate fine subangular blocky structure; soft; non-effervescent.
A3 - (10 to 29 inches); dark brown loam; about 15 percent clay; 10 percent fine and
medium gravel; moderate medium subangular blocky structure; slightly hard; non-
effervescent.
>29 inches, cobbly
08/26/2020
4
Table 1. Topsoil Stripping Areas, Depths & Volumes
TABLE 1
Topsoil Stripping Areas, Depths & Volumes
Burlingame Ranch Phase II
Topsoil No.
Area (ft²)
Stripping
Depth (in.)
Estimated
Volume (yd³)
Adjusted
Volume (yd³)*
Unit 1 166,081 20 10,252 8,919
Unit 2 136,272 17 7,150 6,220
Unit 3 223,877 10 6,910 6,012
Unit 4 32,154 4 397 345
Unit 5 56,912 0 0 0
Unit 6 87,345 0 0 0
TOTAL 702,641 n/a 24,709 21,496
*Please note, the Adjusted Volume assumes a 3% loss due to handling and storage, and a
10% loss of volume due to the removal of coarse fragments greater than 0.5 inches from
material to be used in the upper six inches, and coarse fragments greater than three inches to
be used in the 6-12 inch layer when the topsoil is reapplied.
08/26/2020
5
5.1.2 Unit 2 - 17” Topsoil
Pit 1 was described from the northern portion of the project area in a gently sloping swale.
The surface in the vicinity of the pit contains about 5 percent gravel, 1 percent cobbles and
0.5 percent stones and boulders. This soil has 19 inches of suitable topsoil.
Oi – (0 to 2 inches) slightly decomposed organic matter
A1 - (2 to 7 inches) very dark brown loam; about 15 percent clay; 15 percent fine and
medium gravel; moderate fine granular structure; soft; non-effervescent.
A2 - (7 to 19 inches); very dark brown loam; about 15 percent clay; 15 percent fine
and medium gravel; moderate medium subangular blocky structure; slightly hard;
non-effervescent.
>19 inches, cobbly
5.1.3 Unit 3 - 10” Topsoil
Pit 25 was described from the southern portion of the project area in a gently sloping
backslope. The surface in the vicinity of the pit contains about 10 percent gravel, 1 percent
cobbles and 1 percent stones and boulders. This soil has 13 inches of suitable topsoil.
A1 - (0 to 6 inches) very dark brown loam; about 14 percent clay; 25 percent fine and
medium gravel; moderate fine granular structure; soft; non-effervescent.
A2 - (6 to 13 inches); dark brown loam; about 15 percent clay; 25 percent fine and
medium gravel and 2 percent cobbles; moderate medium subangular blocky structure;
slightly hard; non-effervescent.
>13 inches, cobbly
5.1.4 Unit 4 – Disturbed with 4” Topsoil
Pit 30 was described from the eastern side of the project area on a steep backslope that had
been cut into and then 4 inches of topsoil placed on the cut surface. This soil has 4 inches of
suitable topsoil; however, it may be difficult to salvage due to the steepness of the slope and
may not be practical due to the small volume and close proximity to existing housing.
A - (0 to 4 inches) very dark brown loam; about 18 percent clay; 25 percent fine and
medium gravel; moderate fine subangular blocky structure; slightly hard; non-
effervescent.
>4 inches, cobbly
5.1.5 Unit 5 - Rocky Ridges with No Suitable Topsoil
This unit consists of low lying rocky ridge tops with 40 to 50 percent coarse fragments on the
surface. Pit 6 was described on a narrow ridge top in the northern portion of the project area.
A - (0 to 8 inches) very dark brown loam; about 15 percent clay; 30 percent gravel
and 20 percent cobbles; moderate fine granular structure; soft; non-effervescent; too
rocky for topsoil.
Bw - (8 to 13 inches); brown sandy loam; about 15 percent clay; 45 percent gravel
and 20 percent cobbles; moderate medium subangular blocky structure; slightly hard;
non-effervescent; too rocky and too low organic matter content for topsoil.
5.1.6 Unit 6 - Disturbed Lands
This unit consists of disturbed lands with no usable topsoil, and it occurs in two locations on
the project site. The larger, southern of these two disturbed areas is currently used as
landscape material storage, and along the northern side of this disturbance, the topsoil has
been removed and much of it has a gravel surface. The northern of the two disturbed areas is
currently used for storage of large rocks.
08/26/2020
6
5.2 Chemical Characteristics and Suitability of the Soils
Five soil samples from this investigation and seven samples from HP Geotech’s study were
analyzed for agronomic characteristics, and the results are in Appendix B. Soil characteristics
used to help determine the soil’s suitability for the establishment of bluegrass or fescue lawns
are shown in Table 2. These characteristics were taken from guidelines developed by the
NRCS for the establishment of lawns, and for this project, some characteristics were modified
specifically for bluegrass or fescue lawns.
Overall, the topsoil is well-suited for bluegrass and fescue lawns. The topsoils on the site
have a loam, silt loam or sandy loam texture, all of which are well-suited for turf lawns. The
soils have pH values that generally range between 6.3 and 7.0. Kentucky bluegrass (Poa
pratensis) grows best with a soil pH between 6.0 and 7.0. Similarly, tall fescue (Festuca
arundinacea) does best with a pH around 6.5. The low salt content found in the soils is
advantageous for the establishment of turf lawns. Organic matter levels range from about 2.5
to 7 percent, which is generally suitable. As mentioned above, rock fragments are commonly
high in the topsoil, but will be screened to minus 0.5 inches for at least the topsoil that will
make up the upper 6 inches. Screening to minus 0.5 inches will produce a topsoil with about
5 to 10 percent gravel. Nutrient levels are in suitable concentrations, except nitrate-nitrogen
and sulfur, which are low. These nutrients will most likely need to be applied and
incorporated into the topsoil at the appropriate times.
Please note, the above characteristics and suitability of the onsite topsoil reflect the current
condition, however the chemical characteristics will likely change in soils stockpiled for
prolonged periods. Therefore, it is most appropriate to determine the amendments to be
applied based on analytical results from soil samples collected just before or immediately after
the soil is re-spread.
6.0 Recommendations
Below we have provided recommendations for site preparation; topsoil stripping, screening,
storage, and replacement; and for soil amendment applications. The following
recommendations are based on the findings of the soil investigation and on the assumptions
described above in Section 4.0.
6.1 Site Preparation
Removal of the stones and boulders on the surface will require special handling prior to
topsoil stripping. Some of these rocks are up to 4 feet in diameter and may require a
bulldozer to remove. Vegetation and large shrub roots will also need to be removed before
topsoil stripping. This vegetation can be removed by a bulldozer and could then be shredded
and stored onsite and used as mulch in areas designated for natural landscape and on steeper
slopes for slope stabilization. Care must be taken when grubbing vegetation to avoid
removing the upper most layer of organic-rich topsoil.
6.2 Soil Salvage
Topsoil should be salvaged from all areas containing topsoil, with the possible exception of
the cut backslope, which has only 4 inches of topsoil. The suitable topsoil should be stripped
separately and not mixed with any subsoil having lower organic matter. The suitable topsoil
should also be segregated from other soil material when stockpiling. Soil stripping should be
avoided when the soil is wet. For soil stripping, we recommend having a soil scientist onsite
for several hours when soil salvage operations commence to ensure that the proper material
and appropriate depths are being salvaged and stockpiled correctly.
08/26/2020
7
Table 2. Topsoil Criteria for Establishment of Bluegrass or Fescue Lawns
TABLE 2
Topsoil Criteria for Establishment of
Bluegrass or Fescue Lawns
Property
Ideally
Suitable
Less Suitable to
Unsuitable
Limitation
Texture
loam, silt loam,
sandy loam, sandy
clay loam
clay, silty clay,
sandy clay, loamy
sand, sand
either too clayey or
too sandy
pH 6 - 7 <6, >7 too acidic or too
alkaline
Organic matter
%
3-7
<3, >7
too low or too
much organic
matter
Salinity
(mmhos/cm) <4 >4 too salty
Rock
fragments
2mm -3 “
<10 >10 too rocky
08/26/2020
8
6.3 Soil Screening
We recommend screening or sieving the topsoil to remove gravel greater than 0.5 inches in
diameter and all cobbles. This will produce high-quality topsoil with about 5 to 10 percent
fine gravel. To minimize the screening effort, another option would be to screen the material
that would make up the upper 6 inches to minus 0.5 inch, and screen the 6-12 inch topsoil
layer to minus 3 inches.
6.4 Topsoil Storage
Biological, chemical and physical changes occur to topsoil stockpiled for prolonged periods,
mainly as a result of the lack of aeration in the stockpile, but also as a result of mechanized
handling during stripping and stockpiling. Biological changes include a reduction or
elimination of populations of important soil microorganisms, such as mycorrhizae (important
structures that develop when certain fungi and plant roots form a mutually beneficial
relationship), bacteria, fungi, and algae, which are essential in soil nutrient cycling. In
addition, seeds of native plants, rhizomes (underground stems), and other plant parts capable
of producing new plants that are normally found in soils are lost through decomposition
during storage. Chemical changes will include the reduction of both organic matter and
nutrient levels because of the decrease in biological activity. Soil pH may also change from
normal pH ranges found in local soils, which could affect nutrient availability. Physical
changes include reduction in aggregate stability and increases in soil bulk density and
compaction (destruction of pore space continuity and soil structure). Therefore, topsoil should
be handled and stockpiled in a manner that, to the extent feasible, minimizes impacts to the
quality of the topsoil.
Subsoils from the site should be stored separately from the topsoil because storage of this
material on top of the topsoil would further compact and destroy the structure of the topsoil,
reduce the available oxygen, and result in a reduction of beneficial microorganisms and
nutrient availability.
Current plans are to store at least a portion of the topsoil for up to a year in a large pile with
steep slopes; therefore, it must be stabilized to prevent wind and water erosion and then
seeded and mulched to maintain the viability of the upper 12-18 inches of the stockpile. First,
the final grade of the topsoil stockpile must be worked with hand tools or light weight
construction equipment to create a uniformly roughened but firm seedbed. Next, the topsoil
stockpile that is to remain for a prolonged period should to be seeded with a sterile triticale
broadcast at a rate of 100 lbs/acre. After seeding, the stockpile should be hydromulched with
a 100% mat-fiber applied per manufacturer's specifications at the rate of 2,000 lbs/acre and
then tackified per manufacturer's specifications with Startak by ChemStar, applied at the rate
of 100 pounds per ton of mulch.
6.5 Soil Compaction
Compaction from heavy equipment will adversely affect soil plant relations due to decreased
soil water-holding capacity, loss of aeration and pore space, and increased soil bulk density.
To reduce compaction, prior to re-spreading topsoil, areas to be seeded should be ripped with
a chisel plow or other appropriate machinery to a depth of 10-12 inches and then disked to
break up any clumps of soil. Following topsoil placement, seedbeds should be disked/
harrowed prior to seeding. Once the topsoil is removed from the soil stockpile site, it too
should be ripped before seedbed preparation.
6.6 Topsoil, Fertilizer, Woody Mulch & Mycorrhizae Application
There is sufficient topsoil volume to re-spread 12 inches of quality topsoil over the entire site.
When the soil is replaced it should not be wet, and to prevent settling, it should be lightly
compacted.
08/26/2020
9
Since soils stockpiled for prolonged periods will be physically, chemically and biologically
altered, soil samples should be collected, either from within the soil stockpile just prior to
replacement or from replaced topsoil before seeding, and analyzed for soil parameters and
nutrients that are essential for plant establishment and growth. Sample results would then be
evaluated for soil amendment requirements. Re-spread soils will likely require a biological
stimulant, fertilizer and mulch.
Replenishment of soil microorganisms will occur with interim revegetation of soil stockpiles
but would be limited to the surface (the top 6 to 8 inches) of the stockpile. Most stockpiled
soil will have reduced biological activity. Mycorrhizae are also eliminated in soil stored for
prolonged periods. To promote the rebuilding of mycorrhizae in re-spread surface soils,
mycorrhizal fungi should be incorporated into the upper 6 inches of soil as pellets during
seeding.
In areas selected for natural landscaping, mulch, such as the chipped vegetation from the site,
or compost could be incorporated into the topsoil to enhance organic matter levels, help build
soil structure, provide nutrients, and increase soil stabilization. If areas designated for
bluegrass or fescue lawns require organic amendments, compost is recommended. Organic
amendment requirements should be determined by evaluating chemical properties from
samples of re-spread topsoil, or from the soil stockpile just prior to replacement.
Any fertilizer, mycorrhizae and organic amendments should be thoroughly worked into the
upper 6 inches of the soil with a field cultivator or other appropriate equipment. Next, the
soil surface should be tilled to create a firm, smooth and uniform surface for planting.
7.0 Conclusions
• The soils are suitable for the establishment of bluegrass or fescue lawns, but will likely
require nitrogen and sulfur applications at the appropriate times.
• There is adequate topsoil to cover all landscaped and open space areas with 12 inches
of quality topsoil.
• To produce a quality topsoil, the topsoil should be screened to minus 0.5 inches, at
least for the upper 6 inches to be applied, and to minus 3 inches for the 6-12 inch
layer.
• If topsoil is to be stockpiled for prolonged periods, stabilization of stockpiles will be
necessary to minimize erosion.
• Soil amendment requirements for re-spread soils will need to be determined from
samples collected from either within the stockpile or from re-spread soils.
8.0 Disclaimer
Due to the depositional nature of the soils, topsoil thicknesses are highly variable within any
given area, and the actual thickness of topsoil in a specific area may vary by several inches or
more than the average thickness calculated for that area. The topsoil thicknesses and volumes
presented in this report represent an estimate and will likely vary.
08/26/2020
10
9.0 References
USDA-SCS. 1992. Soil Survey of Aspen-Gypsum Area, Colorado, Parts of Eagle, Garfield, and
Pitkin Counties. USDA – Soil Conservation Service (SCS).
08/26/2020
11
10.0 Figures
08/26/2020
BASE: USGS 7.5 Minute Aspen, Colorado Quadrangle
Photorevised: 1987
Scale 1" = 2000'
Contour Interval = 40'
FIGURE 1. Project Location Map
Burlingame Ranch Phase II
T
1
0
S
I
T
9
S
Map
LocationCOLORADO
WESTERN
ECOLOGICAL
RESOURCE, INC.
711 Walnut Street Boulder, CO 80302
Project Site
R 85 W
12
08/26/2020
13
08/26/2020
14
Appendix A. Brief Soil Descriptions
08/26/2020
15
Soil Descriptions
Pit 1: 0-19 inches, very dark brown loam, 15 percent gravel, cobbles at 19 inches.
Pit 2: 0-10 inches, very dark brown loam, 15 percent gravel, cobbles at 10 inches.
Pit 3: 0-19 inches, very dark brown loam, 15 percent gravel, cobbles at 19 inches.
Pit 4: 0-17 inches, very dark brown loam and very dark grayish brown sandy loam, 18
percent gravel, cobbles at 17 inches.
Pit 5: 0-10 inches, very dark brown loam, 15 percent gravel; 10-18 inches, brown loam, 15
percent gravel, 20 percent stones.
Pit 6: 0-8 inches, very dark brown loam, 30 percent gravel, 20 percent cobbles; 8-13 inches,
brown sandy loam, 45 percent gravel, 20 percent cobbles.
Pit 7: 0-8 inches, very dark brown sandy loam, 15 percent gravel, 5 percent cobbles; 8-13
inches, very dark brown sandy loam, 20 percent gravel, 40 percent cobbles.
Pit 8: 0-7 inches, very dark brown sandy loam, 15 percent gravel, 5 percent cobbles, more
cobbles at 7 inches.
Pit 9: 0-20 inches, very dark brown loam, 20 percent gravel, 5 percent cobbles; 20-24 inches,
brown loam, 20 percent gravel, 25 percent cobbles.
Pit 10: 0-22 inches, very dark brown loam, 20 percent gravel, 5 percent cobbles, more
cobbles at 22 inches.
Observation 11: Rocky knob, surface contains 10 percent gravel, 25 percent cobbles, and 5
percent stones.
Pit 12: 0-9 inches, very dark brown loam, 25 percent gravel, 5 percent cobbles, more cobbles
at 9 inches.
Pit 13: (Old pit) 0-6 inches, very dark brown loam, 15 percent gravel; 6-16 inches, dark
brown loam, 20 percent gravel and 20 percent cobbles; 16-30 inches, brown sandy clay loam,
40 percent gravel, 20 percent cobbles.
Pit 14: 0-20 inches, very dark brown loam, 25 percent gravel, cobbles at 20 inches.
Pit 15: Small cut, 0-14 inches, very dark brown loam, 20 percent gravel, 20 percent cobbles,
and 5 percent stones; > 14 inches many cobbles.
Pit 16: 0-21 inches, very dark brown loam, minor gravel, cobbles at 21 inches.
Pit 17: 0-19 inches, very dark brown and dark brown loam, 20 percent gravel, cobbles at 19
inches.
Pit 18: 0-20 inches, very dark brown loam, 20 percent gravel, cobbles at 20 inches.
Pit 19: 0-23 inches, dark brown loam, 20 percent gravel, cobbles at 23 inches.
Pit 20: 0-29 inches, very dark brown and dark brown loam, 10 percent gravel, cobbles at 29
inches.
08/26/2020
16
Observation 21: Rocky knob, 10 percent gravel, 30 percent cobbles and 1 percent stones on
surface.
Pit 22: 0-23 inches, very dark brown loam, 15 percent gravel, cobbles at 23 inches.
Pit 23: 0-16 inches, very dark brown and dark brown sandy loam, 35 percent gravel, cobbles
at 16 inches.
Pit 24: 0-23 inches, very dark brown loam 15 percent gravel, cobbles at 23 inches.
Pit 25: 0-13 inches, very dark brown and dark brown loam and sandy loam, 25 percent
gravel and 1 percent cobbles, more cobbles at 13 inches.
Pit 26: Open shallow pit, 0-12 inches, very dark brown loam, 10 percent gravel, 40 percent
cobbles, 1 percent stones.
Pit 27: 0-7 inches, dark brown loam, 15 percent gravel, greater than 7 inches many cobbles.
Pit 28: 0-8 inches, dark brown loam, 15 percent gravel, cobbles at 8 inches.
Pit 29: 0-16 inches, very dark brown and dark brown loam, 15 percent gravel, cobbles at 16
inches.
Pit 30: Cut slope, 0-4 inches, very dark brown loam, 25 percent gravel, cobbles at 4 inches.
Pit 31: 0-8 inches, very dark brown loam, 20 percent gravel, cobbles at 8 inches.
08/26/2020
17
Appendix B. Soil Laboratory Results
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020
08/26/2020