HomeMy WebLinkAbout1.04 DRMS Report
North Hangs Mine
112(c) Construction Material
Reclamation Permit Operation
Application to the Colorado Division
of Reclamation, Mining, and Safety
November 2021
By:
Western Slope Materials
Represented by:
WESTERN SLOPE MATERIALS
A STEWART COMPAN Y
II
Lewicki & Associates
North Hangs
November 2021
Table of Contents
Introduction
EXHIBIT A ..................................................................................................................................... LEGAL DESCRIPTION
EXHIBIT B ................................................................................................................................................... LOCATION MAP
EXHIBIT C ......................................................................................................... PREMINE AND MINE PLAN MAPS
EXHIBIT D ........................................................................................................................................................ MINING PLAN
EXHIBIT E ................................................................................................................................. RECLAMATION PLAN
EXHIBIT F ..................................................................................................................................... RECLAMATION MAPS
EXHIBIT G .................................................................................................................................. WATER INFORMATION
EXHIBIT H ............................................................................................................................. WILDLIFE INFORMATION
EXHIBIT I ..................................................................................................................................... SOILS INFORMATION
........................................................................................... Appendix I-1 NRCS Web Soil Survey
EXHIBIT J ................................................................................................................... VEGETATION INFORMATION
EXHIBIT K .............................................................................................................................. CLIMATE INFORMATION
EXHIBIT L ..................................................................................................................................RECLAMATION COSTS
EXHIBIT M .............................................................................................................. OTHER PERMITS REQUIRED
EXHIBIT N .............................................................................................................................................. RIGHT OF ENTRY
EXHIBIT O .......................................................................................................... OWNERS OF AFFECTED LAND
.................................................................................................... AND MINERAL TO BE MINED
EXHIBIT P ............................................................................................... MUNICIPALITIES WITHIN TWO MILES
EXHIBIT Q ................................. PROOF OF MAILING OF NOTICES TO THE BOARD OF COUNTY
……….……………………………….COMMISSIONERS AND SOIL CONSERVATION DISTRICT
EXHIBIT R ................................................................................ PROOF OF FILING WITH COUNTY CLERK
EXHIBIT S ........................................................................................ PERMANENT MAN-MADE STRUCTURES
RULE 1.6.2(1)(B)
GEOTECHNICAL STABILITY EXHIBIT
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Introduction
The North Hangs Mine is a sand and gravel operation located approximately one mile west
southwest of Silt, CO located along the Colorado River just north of Interstate 70. The operation
will excavate, process, and send offsite construction materials from a 72.8 acre permit and
affected area. Access will be from the existing County Road 316 connection for the property.
The owner of the land is North Hangs Ranch LLC. The operator and permittee is Western Slope
Materials, LLC (WSM).
The current site condition is predominantly irrigated fields. The site will be reclaimed to a
groundwater lake, permanent processing area, and surrounding rangeland. Mining will be
conducted in two phases. Details of mining and reclamation plans can be seen on the maps in
Exhibits C and F.
_.)t( Greg l,ewk•i and Associates, P I.I.C
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EXHIBIT A LEGAL DESCRIPTION
The site is approximately 1 mile west southwest of Silt, CO in Garfield County. A legal
description is shown on Map C-1 which is included in Appendix 2. A general location map is
enclosed in Exhibit B.
1. Legal Description
A Parcel of land being a portion of that property described within that Warranty Deed recorded
as Reception No. 682731 of the Garfield County records situated in Government Lot 3,
Government Lot 4, and the West 1/2 of the Southwest 1/4 of Section 9, Township 6 South,
Range 92 West of the Sixth Principal Meridian, Garfield County, State of Colorado lying
Northeasterly of the Northeasterly Right-of-Way of Interstate Highway No. 70 and that property
lying northerly of said Lot 3 and Lot 4 and Southwesterly of the centerline of the Colorado River
within said Section 9; Said Parcel of land being more fully described as follows:
Beginning at the West one quarter corner of said Section 9, thence along the westerly boundary
of said West 1/2 of the Southwest 1/4 S.00°45'15"E a distance of 595.17 feet to a point on said
Northeasterly Right-of-Way of Interstate Highway No.70; thence leaving said westerly boundary
and along Northeasterly Right-of-Way the following 3 courses:
1.) N 55°58'53" E 1302.00 feet;
2.) N 75°16'53" E 227.00 feet;
3.) N 55°58'53" E 1067.22 feet to a point in the centerline of said Colorado River thence leaving
said Northeasterly
Right-of-Way and along said centerline the following seven (7) courses:
1.) N 50°00'00" W 570.12 feet;
2.) N 35°00'00" W 450.00 feet;
3.) N 65°00'00" W 425.00 feet;
4.) N 75°00'00" W 475.00 feet;
5.) S 80°00'00" W 250.00 feet;
6.) N 89°00'00" W 300.00 feet;
7.) S 85°00'00" W 130.00 feet to a point on the westerly boundary of said Section 9;
thence leaving said centerline and along said westerly boundary S.00°45'15".E a distance of
1776.33 feet to the Point of Beginning, having an area of 72.8 acres.
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EXHIBIT B LOCATION MAP
North Hangs Mine
Silt, CO
North Hangs
Mine Entry:
39.54161°N, -107.67733°W
The National Map Advanced Viewer
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0.0 2 km
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EXHIBIT C PREMINE AND MINE PLAN MAPS
Map C-1 Current Conditions
Map C-2 Phase 1 Mining Plan
Map C-3 Phase 2 Mining Plan
Map C-4 Cross Sections
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EXHIBIT D MINING PLAN
1. Introduction
The following is the mining plan for the proposed North Hangs Mine to be operated by permittee
WSM. WSM proposes to mine the North Hangs Mine gravel deposit to support its construction
materials activities in the Silt, CO area. Material will be mined and processed at the North
Hangs Mine. There is sufficient topsoil and overburden onsite to successfully reclaim the site to
its final condition of a lake with rangeland slopes. Crushed rock, sand, washed rock, and
concrete will be produced on site.
2. Pre-Mining and Topsoil Stripping
The site of the proposed North Hangs Mine is currently irrigated fields (see Map C-1). The
Bernudy Ditch (WDID 4500524)1 is located within the permit area but will not be affected by
mining until Phase 2. Prior to the start of Phase 2, a reroute pipe will be installed to maintain the
ditch for its users.
Prior to beginning activities on the site, the boundaries of the affected area will be clearly
marked. Signs and markers will be posted at the mine entrance listing the name of the Operator,
Western Slope Materials, LLC (WSM), and the operation name, “North Hangs Mine”; a
statement that a reclamation permit for the operation has been issued by the Colorado Mined
Land Reclamation Board; and the DRMS permit number. The current access to the property will
be used for mining (Map C-2). Internal roads and ramps will be used throughout the life of the
mining operation as needed and will all be reclaimed. Exhibit C maps show the pre-mine, Phase
1 mining plan, Phase 2 mining plan, and cross sections.
Topsoil and overburden will be stripped at North Hangs Mine and either placed in stockpiles and
berms or direct placed to create final reclamation slopes. This stripping will take place in
advance of mining of areas but is not anticipated to happen all at once. Exhibit C maps show
the areas of disturbance. Berms will be installed at the start of operations on the site as part of
stormwater controls and visual/noise blocking (Map C-2). Berms will be vegetated within 90
days of construction.
Topsoil that is stripped and not required for the construction of the stormwater control berms will
be immediately placed as part of contemporaneous reclamation, stockpiled on-site in the topsoil
storage area, or shipped offsite. Temporary stockpiles of overburden or topsoil required for
reclamation will typically be <20 feet in height. Temporary stockpiles will be located in the
designated area shown on Exhibit C maps. Mining will take place to the slopes identified on
Exhibit C maps. Backfill will take place to achieve final reclamation slopes and grades.
1 https://dwr.state.co.us/Tools/Structures/4500524
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Overburden present on site will be stripped during mining and either placed directly on mined
out ground as part of reclamation, stored in the stockpile area, or be sold as fill. Details on
topsoil and overburden quantities and material balance can be found in Table D-3 and Table E-
3.
3. Mining Phases
Mining will take place in two phases. Once topsoil and overburden are stripped from the site, the
deposit will be mined using shovels or loaders and haul trucks. The groundwater table is roughly
four feet below ground level based on Western Slope’s experience at their existing mine in the
same aquifer, to the southeast (Grand River Park). Since groundwater will be
exposed/encountered during mining, the entire pit will be dewatered using a pump. Details
regarding this dewatering can be found in Exhibit G.
Mining will progress in the dewatered pit as shown on Maps C-2 and C-3. All mining will be to
final 2H:1V slopes on the perimeter. The active mining highwall will be mined to the halfway
point of the final mining slope. This will allow the active mining highwall to be knocked down to
the final mining slope with a dozer when mining is complete in an area. Two maximum mining
disturbance scenarios will exist, one for each mining phase. No more than 25 acres of total
disturbance will take place at any time.
Phase 1
Phase 1 mining will consist of mine operations on the north and south sides of the Bernudy
Ditch with the ditch still in its pre-mining condition. Phase 1 mining will stay at least 250 feet
from the Colorado River. This phase is shown on Map C-2. In the event that mining ceases in
this scenario, reclamation will take place to backfill slopes to 3H:1V or shallower. This is shown
on Map F-1. The end result would be approximately 10 acres of lake across two exposed
groundwater lakes and surrounding rangeland . A discussion on water rightsfor groundwater
exposure can be found in Exhibit G.
Phase 2
Phase 2 mining will consist of a single excavation. It will take place once the Bernudy Ditch has
been rerouted via a pipe around the mining area. At that time, mining of the existing ditch route
will be conducted. This phase is shown on Map C-3. At the end of mining in this phase
reclamation will take place to backfill slopes to 3H:1V or shallower. This is shown on Map F-2.
The end result would be approximately 25 acres of lake across a single exposed groundwater
lake. A discussion on water rights for groundwater exposure can be found in Exhibit G.
4. Equipment
Table D-1 shows the type of equipment that will be used for the operations of this site. Once
operations are complete, all equipment will be removed from the site.
3.1.
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Table D-1 - Typical Onsite Equipment
Equipment Type Phase 1 Quantity
Excavator 1
Bulldozer 1
Water Truck 1
On-highway Dump
Truck
Varies with production
Road Grader 1 (occasionally)
Loader 1
A portable fuel tank will be set up in the mining area to supply equipment onsite. It will have full
secondary containment. All equipment onsite will have onboard diesel tanks in full secondary
containment. Full secondary containment has 110% of the volume of the tank that is in it.
5. General Mining Plan – Method of Mining
Mining at the North Hangs Mine will be conducted in two phases. Phase 1 will mine around the
Bernudy Ditch and to 250 feet from the Colorado River. Phase 2 will mine through the ditch and
to within 100 feet of the Colorado River. Phase 2 mining will not begin until a reroute of the
Bernudy Ditch is complete. The overall mining direction will be from south to north and will vary
within each pit. Maps C-2 and C-3 show the extents of mining in each phase. All mining maps
can be found in Exhibit C. Each mining plan shows the maximum disturbed area for that phase.
Table D-2 shows the disturbed and undisturbed area in each phase. Crushing and screening of
excavated material will take place onsite. Crusher fines may be placed in the lake during final
reclamation or sold offsite as fill. Concrete will be produced onsite. Washed rock will be
produced onsite. No asphalt will be produced onsite. All facilities will be removed following
mining.
Explosives will not be used at this site.
Table D-2. Disturbance Area by Phase
Disturbed Area Undisturbed Area
Phase 1 39.3 acres 33.5 acres
Phase 2 45.8 acres 27 acres Note: The total affected area is 72.8 acres.
Mining Buffers and Limitations
Minimum mining setbacks are shown on Map C-3 (Phase 2). Map C-2 shows the setbacks
during Phase 1. All mining will be within the 100-year floodplain. Stormwater control structures
will be present during mining but removed during reclamation. Additionally, the excavation of
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topsoil and overburden from the site will create storage volume for storm and flood events
onsite. See Map G-1 in Exhibit G for more information on surface water management.
6. Overburden and Topsoil Handling
Initial earthmoving will consist of stripping 0-36 inches of topsoil and approximately one to four
feet of overburden from areas to be disturbed. These stripping thicknesses are based on the soil
survey for the operation and operational experience at the Grand River Park to the east. For the
purpose of the material balance, 18 inches of topsoil and two feet of overburden are assumed.
All earthmoving will be done using mining equipment suitable for this type of operation including
the following: front end loader, dozer, excavator, and water trucks. Topsoil and overburden will
be directly placed, as much as possible, with stockpiling as needed in the designated stockpile
areas (Map C-3). Stockpiles to be in place longer than 90 days will be seeded with the
permanent seed mix to prevent erosion (see Exhibit E for seed mix information). Table D-2
details a breakdown of the overall material balance of the project during mining.
Table D-3. Topsoil and Overburden Material Generated During Mining
Material
Generated (CY)
Topsoil 110,800
Overburden 239,400
The presence of the lake means that there will be more topsoil and overburden generated by
stripping activities than needed for reclamation activities. The excess material will be used to
achieve the grading shown in the Exhibit F maps and to augment topsoil thickness in areas
above ten feet below the average water level of the lakes. Details pertaining to reclamation can
be found in Exhibit E.
7. Stormwater – Diversions and Impoundments.
Surface water from storms, known as stormwater runoff, will be collected in the mining pit during
operations. As shown on Map G-1, the local drainage area consists principally of the North
Hangs Mine and immediate area. The pit will act as a sediment pond during operations. No
diversion of upstream waters will occur. Impounding of water will only be temporary, to trap
sediment, with all stormwater runoff leaving the site within 72 hours. Exhibit G covers surface
water management in detail.
8. Mining Timetable
An approximate mining timetable for the mining operation is shown on Table D-4.
Table D-4. Mining Timetable
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Years Activity
1-2 Stripping of processing area and initial pit of Phase 1.
2-10 Phase 1 mining
10-15 Phase 2 mining
Over the life of the mine, a total of 1.5 million tons of material will be extracted at a rate of
roughly 100,000 tons per year. This will result a mine life of approximately 15 years, depending
on market conditions.
Upon the completion of mining, the processing area will be used by Western Slope Materials to
process import material for production. Final reclamation of the processing area will take place
once processing of import is not longer part of the operation at some point in the future.
9. Disturbance Area
Concurrent reclamation will take place as much as possible. The maximum unreclaimed
disturbance area will be limited to 25 acres. See Exhibit L for a detailed discussion of the
reclamation costs and bond calculations.
10. Deposit and Underlying Stratum Geology
Mapped Geology
A soil report was generated using the United States Department of Agriculture’s Natural
Resources Conservation Services’ (NRCS) Web Soil Survey (WSS)2 and is included with this
permit application (Exhibit I Soil Report) along with a site specific soil investigation .
The main applicable United States Geological Survey geologic map for the site is from 2001.
The area of the North Hangs Mine was mapped by Shroba and Scott (2001)3 as consisting of
Holocene and Pliestocene age clast-supported, slightly bouldery, pebble and cobble gravel in a
sand to sandy silt matrix. The North Hangs deposit is underlain by the Eocene to Paleocene
Wasatch Formation, specifically the Eocene aged Shire Member, a nonmarine, predominantly
multicolored fine-grained clastic intervals of thick claystone, mudstone, and siltstone
interbedded with less abundant intervals of minor coarse-grained clastic beds of thin fluvial
sandstone.
2 https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm.
3Shroba R.R. and Scott, R., (2001). Geologic Map of the Silt Quadrangle, Garfield County, Colorado. Denver, CO:
United States Geological Survey.
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Geology and Resource Discussion
Details of the Natural Resources Conservation Service (NRCS) site-specific soil report (Exhibit
I) indicate that the deposit is a minimum of 5 feet deep in the area of the deposit. Shroba and
Scott (2001) indicate that gravel deposits along the Colorado River are typically 1-6 meters (~3
to 18 feet) deep. Material balances for reclamation purposes will be calculated using a topsoil
depth of 18 inches.
Mining will proceed to two feet off of bedrock or a depth of 25 feet; whichever is encountered
first. This depth is based on the operator’s experience within the same deposit in Grand River
Park to the east. No bedrock will be exposed by mining.
11. Primary and Secondary Commodities
The operation will produce raw materials including sand, gravel, and rock. These materials will
all be processed onsite into construction materials such as rock, sand, fines, and concrete.
Excess overburden will be sold from the site as fill. Excess topsoil may be shipped offsite for
use. Necessary overburden and topsoil will be maintained onsite to retain the backfill needed for
reclamation. Inert material may be imported for backfilling purposes. Any backfill imported for
this purpose will be certified inert with an affidavit signed by the importee.
Western Slope Materials will clearly mark the permit/affected area boundary with stakes
surveyed on site prior to mining.
No designated chemicals or acid-producing materials to be used or stored on-site.
12. Water Information, Rights and Augmentation
All water rights issues such as availability of water for this operation, consumption rates, dust
control, etc. is presented in Exhibit G - Water Information.
10.2.
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EXHIBIT E RECLAMATION PLAN
1. Introduction
This exhibit describes the plans and processes involved in reclaiming the site and transforming
it to its ultimate post-mining use as industrial, rangeland , and a groundwater lake as shown on
Exhibit F maps. Reclamation will occur contemporaneously as portions of the permit area are
mined. Final reclamation of the permit area will occur after the cessation of all mining activities.
Current use of the permit area is irrigated fields. Final use of the permit area is proposed to be
rangeland with a groundwater lake. Pursuant to Rule 6.4.5.2.(b), the applicant evaluated the
proposed post-mining land use in regard to adopted state and local land use plans for this area
and land uses in the vicinity. The proposed post-mining use of industrial and rang eland with an
open water pond is compatible with the general character of the area.
The affected area of this site is the same as the permit area of this site, 72.8 acres, not all of
which will be disturbed and require reclamation. The tables below provide a summary of
intended end uses within the affected area upon completion of reclamation in each phase.
Table E-1. Reclamation Areas (Phase 1) Description Area (Acres) Gravel Access Roads 1.5 Industrial/Commercial Area 7.5 Mining Area Reclaimed to Rangeland 15 Groundwater Lake 15.9 Disturbed Area Total 39.9 Undisturbed Area within the Permit Area 33.5 Total Affected (Permit) Area 72.8
Table E-2. Reclamation Areas (Phase 2) Description Area (Acres) Gravel Access Roads 1.5 Industrial/Commercial Area 7.5 Mining Area Reclaimed to Rangeland 5.3 Groundwater Lake 25 Disturbed Area Total 45.8 Undisturbed Area within the Permit Area 27 Total Affected (Permit) Area 72.8
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Note: Undisturbed area includes setbacks and incidental areas within the permit where disturbance is not needed.
2. General Reclamation Plan
Mining will take place to the slopes and extents shown in Exhibit C. Reclamation will be
conducted to create the final conditions shown in Exhibit F. Backfilling, grading, topsoiling, and
revegetation of the disturbed areas outlined in Exhibits C and F will be conducted in a similar
manner, as outlined in Exhibit E. Reclamation will start prior to mining with the transplanting of
the existing mature cottonwood trees on site to the outskirts of the mine. This will aid in
screening during mining and post mine reclamation as the fully grown trees remain intact.
Reclamation will be conducted on final slopes by covering the area with an average of 18 inches
of topsoil and seeded with the seed mix found in Table E-4. Efforts will be made to not strip any
topsoil until it can be directly placed on areas ready for reclamation; however, when necessary,
topsoil will be stored into either berms or the stockpile area as shown on Map C-2.
Dewatering will be conducted throughout the mining operation’s life. Following final topsoiling
and revegetation, the pit pump(s) will be removed. Reclamation will be conducted concurrently
with mining to minimize disturbed ground.
In both phases reclamation will consist of backfilling and grading slopes to variable conditions
as shown on Maps F-1 and F-2. Slopes will be no steeper than 3H:1V to at least 10 feet below
the anticipated water level of the groundwater lakes. Backfilling of Pit 1, early in Phase 1, will
allow for the development of wetlands in that area prior to the disturbance of wetlands
elsewhere onsite. For all other portions of Phase 1, reclamation will consist of creating the
shorelines along the lake to be created by Phase 2 mining. In the event that the ditch reroute
does not occur, the reclamation of the site will create two lakes as opposed to one, leaving the
Bernudy Ditch and existing wetlands undisturbed.
3. Topsoil and Overburden Handling
Topsoil and overburden handling will be identical for all Phases and Options.
It is not anticipated that any topsoil will need to be imported for the reclamation process, even at
the point of greatest disturbance. The creation of groundwater lakes will lead to an excess in
both topsoil and overburden.
Topsoil and overburden stripped during mining will either be stored in the temporary stockpile
area or will be directly placed as part of final reclamation. Topsoil and overburden will be
maintained in separate stockpiles in the temporary stockpile area and berms. Table E-3 outlines
the topsoil and overburden material balance calculations during reclamation and during the
greatest disturbance area scenario. Excess overburden or topsoil generated during mining will
be placed in reclaimed areas or shipped offsite. Overburden will not be stripped from berm or
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road areas. Topsoil stripping and replacement volumes are based on an average topsoil depth
of 18 inches. Overburden stripping is based on two feet of overburden on site.
Table E-3. Topsoil and Overburden Material Balances During Reclamation
Material
Generated by
Mining (CY)1
Material
Required for
Reclamation
(CY)2
Note
Phase 1 Topsoil 96,500 54,400
Phase 1 Overburden 72,000 112,000 Excess topsoil used to augment backfill.
Phase 2 Topsoil 110,800 40,000
Phase 2 Overburden 239,400 240,000 Excess topsoil used to augment backfill. 1Topsoil and overburden stripped during mining. Based on soil survey thicknesses and area mining experience. Total at the conclusion of a given phase. 2Topsoil or overburden needed to reclaim disturbed areas in said scenario. Total at the conclusion of the given phase.
As demonstrated in Table E-3, topsoil generated by stripping will be more than enough to
successfully reclaim all disturbed areas in the greatest disturbance area scenario. WSM will
maintain enough topsoil onsite in stockpiles to successfully reclaim the disturbed area to its final
uses.
4. Final Use
The total affected area on the site is 72.8 acres, the same as the permit area. A maximum of
45.8 acres will be disturbed by mining activities. When the site is fully reclaimed, the final use of
the affected area will be as listed in Table E-1 and as depicted on the Exhibit F maps. The post-
mining land use will be compatible with the current existing land uses in the surrounding area.
5. Topsoil and Revegetation Plan
Throughout the reclamation process, topsoil will be replaced to a depth of 0-36 inches (18
inches on average) on all disturbed areas except those areas that will become the groundwater
lake, the industrial/commercial area, and the a ccess roads. However, for the purpose of material
balance, it is assumed that the industrial/commercial area will be topsoiled. Table E-3 is
calculated based on this assumption. Topsoil available from stripping is in excess of that
needed for reclamation. In accordance with Rule 6.4.5(2)(b).
The mature cottonwood trees within the mining area will be transplanted prior to mining. They
will be moved to the areas in front of the processing area and concrete batch plant to aid in
screening and will remain in their transplanted location for final reclamation. Additional saplings
will be planted near the reclaimed lake and towards the river in the northeast of the site.
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The seed mix for revegetation of the site was chosen because it will establish a diverse,
effective, and long -lasting vegetative cover that is capable of self-regeneration without
continued dependence on irrigation, soil amendments or fertilizer, and provides equal or better
coverage than the existing vegetation of the surrounding area. Plantings will be limited to
grasses and forbs that are well-suited to the property considering the soils and climate. Table E-
4 shows the rangeland revegetation seed mix. Table E-5 shows the wetland fringe revegetation
seed mix. The wetland mix will be applied in all wetland areas designated on the Exhibit F
maps.
The revegetation plan considers environmental factors such as seasonal patterns of
precipitation; temperature and wind; soil texture and fertility; slope stability; and direction of
slope faces to provide the greatest probability of success with plant establishment and
vegetation development.
Table E-4. Rangeland – Permanent* Seed Mix
Species* Percentage of mix (%) Project Drill Seed Mix Rate
(lbs PLS** per acre)
Palome Indian ricegrass 20% 6
Ephraim crested wheatgrass 10% 3
Canbar canby bluegrass 3% 1
Sodar streambank wheatgrass 10% 3
Canada wildrye 20% 2.5
Slender wheatgrass 8% 2.5
Fourwing saltbrush 8% 0.3
Rabbitbrush 1% 0.3
Skunkbrush sumac 1% 0.3
Total 100% 18.9 *Permanent vegetation seed mix consists of native species. **PLS = Pure live seed
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Table E-5. Wetland – Permanent* Seed Mix
Species* Percentage of mix (%) Project Drill Seed Mix Rate
(lbs PLS** per acre)
Nebraska sedge 8% 1
Hardstem bulrush 31% 4
Beaked sedge 8% 1
Alkali bulrush 15% 2
Canada wildrye 19% 2.5
Slender wheatgrass 19% 2.5
Total 100% 13 *Permanent vegetation seed mix consists of native species. **PLS = Pure live seed
Note that the rates given in in the seed mix tables are for a drilled application rate and rates will
be double for a broadcast application. All temporary seeding and berm seeding will be
conducted with the Rangeland seed mix.
To ensure the establishment of a diverse and long-lasting vegetative cover, the operator will
employ site preparation techniques and protection. The soil shall be mechanically conditioned
using disks and rippers, mulch will be spread after seeding, and temporary irrigation may be
employed to ensure germination of as many seedlings as possible. Drill seeding will be utilized
throughout the site.
Certified weed free mulch will be crimped into the surface at 2000 lbs. per-acre. Furrows from
disking will be left in the topsoil to provide moisture concentration and shade areas to promote
better conditions for successful vegetation establishment. Seeding will occur in the first
favorable season following the placement of topsoil.
The site will be prepared to provide the best chance of vegetation establishment by completing
the following as recommended by the NRCS in the Plant materials Technical Note No. 59:
“The seedbed should be well settled and firm but friable enough that seed can be
drilled at the recommended depth. Soils that have been compacted by traffic or other
equipment should be tilled (deep-chisled or ripped if necessary) to break up restrictive
or compacted layers and then harrowed and rolled or packed to prepare the required
firm seedbed. Avoid seedbed preparation when the soil is wet to prevent compaction of
the seedbed. Planting depth less than 1 inch.”
6. Reclamation Timing
Stormwa ter berms will be seeded within 90 days of their construction using the permanent
rangeland mixture. All reclamation activities will be completed within two years of the completion
of mining activities onsite.
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Table E-6 summarizes the timing of reclamation throughout the life of the mine. The anticipated
timing is based on a 15 -year mine life, depending on market conditions. If the mine life is
extended, the appropriate years will be added to the timeline to accommodate reclamation.
Table E-6. Reclamation Timetable
Years Activity
1-2 Stripping of processing area and initial pit from Phase 1.
2-10 Mining of Phase 1. Develop wetland expansion from initial pit. Install ditch reroute pipe.
10-15 Mining of Phase 2 areas.
10-15 Concurrent reclamation onsite.
15+ Processing operations using imported material.
15++ Reclamation of processing area. Revegetation monitoring (two years minimum).
7. Post-Reclamation Site Drainage
Map G-1 shows the post mine drainage conditions in comparison to baseline and mining
conditions.
8. Weed Control
Measures will be employed for the control of noxious weeds. A Weed Control Plan will be
utilized as follows:
1) Every April and October, a weed survey will be taken of the affected area to identify and
map the presence of any noxious weeds listed by the county and the state.
2) If any patches or plants are identified, they will be controlled within 30 days. This may
include mowing, tillage, or spraying them with an herbicide approved for use by the
weed control staff of Garfield County. Other methods of weed control (ie: biological) may
be employed from time to time depending on the nature and extent of the targeted
species.
After reclamation, weed surveys and controls will continue until the perennial vegetation cover
on the site meet DRMS requirements and bond release is obtained.
9. Revegetation Success Criteria
Revegetation will be deemed adequate when erosion is controlled and vegetation is considered
satisfactory according to Division standards. Reclamation is considered a success when a
diverse and long-lasting vegetative cover is established and the site is free of prohibited noxious
weed species that seriously threatens the continued development of the desired vegetation.
Monitoring the reclamation on an ongoing basis will ensure its success. If problems arise, WSM
will consult with the local NRCS office to get input regarding how to resolve the problem. If
minor changes or modifications are suggested by the local NRCS office to the seeding or
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reclamation plan, revision plans will be submitted to the DRMS prior to their implementation. It is
anticipated that the Division will provide assistance and feedback in evaluating the success of
the ongoing reclamation process. Information on all areas disturbed and reclaimed as well as
any other important items regarding the reclamation will be submitted in the annual reports to
the Division.
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EXHIBIT F RECLAMATION MAPS
Map F-1 Phase 1 Reclamation Plan
Map F-2 Phase 2 Reclamation Plan
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EXHIBIT G WATER INFORMATION
The North Hangs Mine affected area is located adjacent to the Colorado River. The disturbance
area of the site will be a minimum of 250 feet from the river in Phase 1 and a minimum of 100
feet from the river in Phase 2. The entire site is within the Federal Emergency Management
Administration (FEMA) Floodplain Zone A (100-YR event). No floodway is mapped in this area,
according to FEMA. Groundwater is roughly four feet below the natural grade and is the alluvial
aquifer of the Colorado River.
This exhibit addresses Rule 3.1.6(1) and demonstrates how the mining and reclamation plans
will minimize any disturbance to the prevailing hydrologic balance of the affected land and
surrounding lands.
1. Water Quality Protection
The main concerns regarding water quality are potential impacts to surface or groundwaters
from sediment, hydraulic fluids, or diesel fuel. Sediment will be controlled through the use of
stormwater retention within the disturbance area throughout the life of the mine. All stormwater
runoff and surface water flows from the local drainage area will be collected with control
measures built around the site. This includes mine slopes and the stormwater berms. This will
contain all sediment within the site and prevent its unattended discharge from the site. Hydraulic
fluids and diesel fuels will be contained within any vehicles through the use of best practices of
maintenance and regular inspections of vehicles, hydraulic lines, and any other potential
sources of spills. Diesel is proposed to be stored on-site in double walled tanks, the additional
wall acting as the required secondary containment. Furthermore, the tanks will be located away
from exposed ground water. Inadvertent spills that occur during fueling or refilling operations will
be cleaned up immediately utilizing spill kits located adjacent to all fueling areas. The fuel farm
location can be seen on Exhibit C maps.
During mining, dewatering will take place within the pit. This will be accomplished using a pit
pump installed below the pit floor. This pit pump will be surrounded by a gravel filter berm. Mine
process and stormwater will discharge via the dewatering system under an approved Colorado
Department of Public Health and Environment discharge permit.
2. Floodplain
The 100-year floodplain is shown on Exhibit C and F maps. The entire disturbance area is within
the floodplain. Temporary stormwater control berms, topsoil, and overburden stockpiles will
exist during mining, but will be removed for reclamation. Additionally, the removal of material
from the site will create storage space below the existing grade and above the groundwater
table, potentially reducing the downstream negative impacts of floods.
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In the event of flooding of the site, the pit pump will be disabled, and equipment removed from
the pit floor. The pit will then be allowed to fill with water. Pumping will only resume once the
flood has passed. All fuel storage onsite will be maintained elevated at least one foot above the
base flood elevation and in secondary containment sufficient to hold 110% of the stored fuel.
Mining will not take place within 250 feet of the Colorado River prior to the construction of
inlet/outlet structures. These structures are outlined on Map C-3. Prior to the development of
Phase 2 mining, the applicant will provide the Division with a technical revision outlining
design specifics of these structures. These design specifications will be in accordance with
the Urban Drainage and Flood Control District, Technical Review Guidelines for Gravel Mining &
Water Storage Activities Within or Adjacent to 100-Year Floodplains. Map C-3 shows the
potential structure designs for reference.
3. Wetlands
WSM commissioned a wetlands survey of the site conducted by Environmental Solutions Inc
(ESI) to determine the extent of wetlands that are present onsite. This survey is attached to the
application in Exhibit J. Wetlands will not be disturbed by Phase 1 mining. Prior to wetland
disturbance in Phase 2, the applicant will secure any applicable US Army Corps of Engineers
(USACOE) permits. No fill of wetlands will take place prior to securing said USACOE permits.
Phase 1 reclamation is intended to incorporate wetland expansion to mitigate wetland
disturbance in Phase 2.
4. Location on Map
See Map C-1 for the location of all tributary water courses, wells, springs, stock water ponds,
reservoirs, and ditches on the affected land and on adjacent lands where such structures may
be affected by the proposed mining operations.
5. Known aquifers
The only known aquifer in the area is the shallow alluvial aquifer of the Colorado River. Depth to
water table is expected to be found at four feet below ground surface, based on the depth to
groundwater experienced by the operator at the Grand River Park operation to the southeast.
According to the U.S. Geological Survey’s Ground Water Atlas of the United States, the only
groundwater aquifer system below the alluvial one in this area is the Unita-Animas Aquifer
System.4 This is located beneath the Mancos Shale that underlays the site alluvium and will not
be reach by mining or affected by mining. Mining will stop at least two feet above the shale
bedrock.
4 https://pubs.usgs.gov/ha/ha730/ch_c/
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6. Surface Water
The North Hangs Mine will interact with surface water in the area via runoff that enters the site.
Map G-1 shows a comparison of the drainage patterns in all three stages of operational life. The
priority for surface water protection at the North Hangs Mine is preventing the discharge of
sediment, oil, and/or hydraulic fluids from the operational areas. Oil and hydraulic fluids are
contained on the site using standard best management practices related to the storage and
transfer of such fluids. These include the use of secondary containment around storage and
transfer points, spill kits, and employee training on safe handling practices. Sediment is trapped
onsite using controls and best management practices related to directing and controlling surface
water runoff that enters disturbed areas.
Appendix G-1 contains all surface water runoff calculations for the North Hangs Mine.
Surface Water Handling – Mining
Surface water runoff will be handled the same way throughout North Hangs Mine’s mine life:
water from all mining disturbance areas will drain into the active mining and processing areas.
The mine’s drainage basin and drainage directions are shown on Map G-1. The majority of the
disturbed area drains into the mining pits. The processing area runoff will drain internally against
the stormwater control berm that rings the processing area.
A stormwater management plan (SWMP) as part of the CDPHE discharge permit for the
operation, will be strictly enforced onsite. This includes the proper maintenance of stormwater
controls such as berms, the proper storage of potential pollutants such as diesel fuel, and the
proper sampling and documentation of sampling from discharge points.
Phase 1 Drainage
During Phase 1 mining, each active pit will drain internally and the processing area will drain
internally. Grading of the site to drain internally, along with the buffers of undisturbed ground
between each mine pit, the Colorado River, and the Bernudy Ditch will ensure that no sediment
laden water flows enter the river or Bernudy Ditch. Undisturbed areas will continue to drain in
the same manner as prior to mining.
Once surface water is collected within the mining pit it will be collected in the pit floor perimeter
ditches and be routed to the pit dewatering pump. The pit dewatering pump will then pump into
existing drainage swales in undisturbed ground onsite to return to the river. Alternatively, pit
dewatering will be discharged into the Bernudy Ditch. The pit pump will always be located at
least two feet below the active mining floor to ensure clean water pumping. Pit pump discharge
will be regulated as a National Pollution Discharge Elimination System (NPDES) discharge point
under an approved CDPHE discharge permit for sand and gravel mining. Such permits monitor,
limit, and enforce potential pollutants in water discharge to ensure downstream water quality is
protected.
6.1.
6.1.1.
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Phase 2 Drainage
During Phase 2 mining, the active pit will drain internally and the processing area will drain
internally. Grading of the site to drain internally, along with the buffers of undisturbed ground
between each mine pit and the Colorado River will ensure that no sediment laden water flows
enter the river. Undisturbed areas will continue to drain in the same manner as prior to mining.
Once surface water is collected within the mining pit it will be collected in the pit floor perimeter
ditches and be routed to the pit dewatering pump. The pit dewatering pump will then pump into
existing drainage swales in undisturbed ground onsite to return to the river. The pit pump will
always be located at least two feet below the active mining floor to ensure clean water pumping.
Pit pump discharge will be regulated as a National Pollution Discharge Elimination System
(NPDES) discharge point under an approved CDPHE discharge permit for sand and gravel
mining. Such permits monitor, limit, and enforce potential pollutants in water discharge to
ensure downstream water quality is protected.
Surface Water Handling – Reclamation
Following reclamation, drainage patterns will be established that are permanent. These are
shown on Map G-1. The post-reclamation drainage patterns will consist of areas of the
reclaimed mining pit(s) that drain into the reclaimed ponds, the processing area drainage which
will continue to drain internally and against the stormwater control berm, and the undisturbed
portions of the site which will drain as they had prior to mining. Dewatering activity will cease
following final reclamation.
7. Groundwater
Groundwater is located approximately 4 feet below the surface of the ground onsite. No wells
are located within 600 feet of the proposed pit5.
Groundwater Handling – Mining
Mining activity will expose groundwater from the very beginning of operations. Dewatering of the
pit will take place to bring the groundwater table below the operating floor. This allows
equipment to safely and effectively mine the alluvial deposit. The pit pump will be active
continuously during the mining season, which typically is mid-April to early-November,
depending on weather. The pit pump will not run during flood events or when temperatures drop
below freezing.
Pit dewatering will intercept groundwater from the alluvial aquifer of the Colorado River that is
onsite and route it back towards the river via discharge outfalls. This process is common among
sand and gravel pits along the rivers and waterways of Colorado. The layout of the dewatering
process can be found on Exhibit C maps and Map G-1, including the typical location of the pit
pump, its typical installation, and dewatering path to the Colorado River. The pit pump will be a
5 https://gis.colorado.gov/dnrviewer/Index.html?viewer=dwrwellpermit
6.1.2.
6.2.
7.1.
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mobile pump with and accompanying diesel generator. This generator will have an onboard fuel
tank with secondary containment. The pump and generator will move as needed to ensure a
properly dewatered mining pit. The pump will be located two feet below the active pit floor. It will
also be surrounded by a gravel filter. Water will then discharge from the dewatering pump via a
pipe or drainage channels to the Colorado River to the north. This system of dewatering is
proven to move the water out of the way of mining operations while trapping sediment on site.
Groundwater Handling – Reclamation
Once mining and reclamation are completed on site, the pit pumping will cease. Permanent
groundwater lakes will form as shown on Map F-1.
Groundwater Exposure and Water Rights
Prior to any groundwater exposure onsite, an approved permanent augmentation plan
will be in place with approval from the Colorado Division of Water Resources and the
applicable water courts A technical revision will be supplied to the Division containing
this approved augmentation plan prior to any groundwater exposure onsite. This plan for
augmentation will ensure that all water depletions are replaced in the system in time, kind, and
location. No mining will take place that exposes groundwater without this plan for augmentation.
Phase 1 water for dust control will be purchased and used onsite in accordance with an
approved Substitute Water Supply Plan.
8. Water Consumption and Sources for the Operation
Water for dust control will be the primary consumptive use onsite during mining. Wash plant
water usage is also figured into this operation. Water will be purchased as needed. A small
amount of evaporation is assumed with the sediment pond onsite. Table G-1 shows a
breakdown of estimate water consumption for the operation during mining.
Table G-1. Water Consumption
Month Gravel
Washing
Dust Control
(crusher and
roads)
Total (ac -ft)
Jan 0.00 0.00 0.00
Feb 0.00 0.00 0.00
Mar 0.02 0.21 0.23
Apr 0.02 0.20 0.22
May 0.02 0.21 0.23
Jun 0.02 0.20 0.22
Jul 0.02 0.21 0.23
Aug 0.02 0.21 0.23
7.2.
7.3.
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Sep 0.02 0.20 0.22
Oct 0.02 0.21 0.23
Nov 0.02 0.21 0.23
Dec 0.00 0.00 0.00
Total 0.18 1.86 2.04
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APPENDIX G-1 SURFACE WATER RUNOFF
CALCULATIONS
All runoff calculations were completed using the Natural Resource Conservation Service
TR-55 methodology.
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Hydrograph Summary Report
1
Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph
No. type flow interval Peak volume hyd(s) elevation strge used Description
(origin) (cfs) (min) (min) (acft) (ft) (acft)
1 SCS Runoff 4.447 60 840 2.128 ------ ------ ------ North Hangs Baseline
2 SCS Runoff 8.447 60 780 3.605 ------ ------ ------ Phase 1 Mining
3 SCS Runoff 10.94 60 780 4.373 ------ ------ ------ Phase 2 Mining
4 SCS Runoff 11.85 60 780 4.649 ------ ------ ------ End of Mining
5 SCS Runoff 10.06 60 780 4.106 ------ ------ ------ Final Reclamation
Surface Hydrology.gpw Return Period: 100 Year Friday, 11 / 5 / 2021
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Friday, 11 / 5 / 2021
Hyd. No. 1
North Hangs Baseline
Hydrograph type = SCS Runoff Peak discharge = 4.447 cfs
Storm frequency = 100 yrs Time to peak = 14.00 hrs
Time interval = 60 min Hyd. volume = 2.128 acft
Drainage area = 64.700 ac Curve number = 74*
Basin Slope = 0.3 % Hydraulic length = 2000 ft
Tc method = LAG Time of conc. (Tc) = 132.40 min
Total precip. = 2.17 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.400 x 98) + (1.500 x 39) + (4.900 x 74) + (23.200 x 74) + (10.900 x 74) + (22.800 x 74)] / 64.700
2
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
4.00 4.00
5.00 5.00
Q (cfs)
Time (hrs)
North Hangs Baseline
Hyd. No. 1 -- 100 Year
Hyd No. 1
-------;\-- -----
(
-
---------\ ------
-\
--\ --------____ " ____ _
---------~----
J 1--" ,..___ .......... ___
-------------,_
-------------~--
------- --~
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Friday, 11 / 5 / 2021
Hyd. No. 2
Phase 1 Mining
Hydrograph type = SCS Runoff Peak discharge = 8.447 cfs
Storm frequency = 100 yrs Time to peak = 13.00 hrs
Time interval = 60 min Hyd. volume = 3.605 acft
Drainage area = 64.600 ac Curve number = 81*
Basin Slope = 0.3 % Hydraulic length = 2000 ft
Tc method = LAG Time of conc. (Tc) = 107.40 min
Total precip. = 2.17 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(12.900 x 89) + (0.600 x 89) + (14.200 x 89) + (35.500 x 74) + (1.400 x 98)] / 64.600
3
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Q (cfs)
0.00 0.00
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
10.00 10.00
Q (cfs)
Time (hrs)
Phase 1 Mining
Hyd. No. 2 -- 100 Year
Hyd No. 2
- - - - - - - - - - - - - -
,......
'
- - - - - - - - - - - - - - - -
- - - - - - - ---- - - - -
,
- - - - - - - -~ - - - - -
"' ~ - - - - - - - - - - --" -
i',.._ J
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Friday, 11 / 5 / 2021
Hyd. No. 3
Phase 2 Mining
Hydrograph type = SCS Runoff Peak discharge = 10.94 cfs
Storm frequency = 100 yrs Time to peak = 13.00 hrs
Time interval = 60 min Hyd. volume = 4.373 acft
Drainage area = 64.600 ac Curve number = 84*
Basin Slope = 0.3 % Hydraulic length = 2000 ft
Tc method = LAG Time of conc. (Tc) = 97.30 min
Total precip. = 2.17 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(40.800 x 89) + (22.400 x 74) + (1.400 x 98)] / 64.600
4
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Q (cfs)
0.00 0.00
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
10.00 10.00
12.00 12.00
Q (cfs)
Time (hrs)
Phase 2 Mining
Hyd. No. 3 -- 100 Year
Hyd No. 3
- - - - - - -~ - - - - - - -
l
- - - - - ---\-- - - - - -
- - - - - - --\-- - - - - -
\ - - - - - - -- - - - - -'
- - - - - - - -~ - - - - -
""-.
........... r--,-.....__
- - - - ---- - - - - --" -
j r--,...__
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Friday, 11 / 5 / 2021
Hyd. No. 4
End of Mining
Hydrograph type = SCS Runoff Peak discharge = 11.85 cfs
Storm frequency = 100 yrs Time to peak = 13.00 hrs
Time interval = 60 min Hyd. volume = 4.649 acft
Drainage area = 64.600 ac Curve number = 85*
Basin Slope = 0.3 % Hydraulic length = 2000 ft
Tc method = LAG Time of conc. (Tc) = 94.00 min
Total precip. = 2.17 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(7.200 x 89) + (34.900 x 74) + (1.400 x 98) + (21.100 x 100)] / 64.600
5
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Q (cfs)
0.00 0.00
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
10.00 10.00
12.00 12.00
Q (cfs)
Time (hrs)
End of Mining
Hyd. No. 4 -- 100 Year
Hyd No. 4
~ - - - - - - - - - - - - - -
\
- - - - - ----\-- - - - - -
I
- - - - - - - ---- - - - -
- - - - - - - - - - - - - - -
- - - - -
,----\ - - - - -
I',,..
.......... r----,....___
- - - - - - - - - - - - -~ -
r--,....__ __J
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Friday, 11 / 5 / 2021
Hyd. No. 5
Final Reclamation
Hydrograph type = SCS Runoff Peak discharge = 10.06 cfs
Storm frequency = 100 yrs Time to peak = 13.00 hrs
Time interval = 60 min Hyd. volume = 4.106 acft
Drainage area = 64.600 ac Curve number = 83*
Basin Slope = 0.3 % Hydraulic length = 2000 ft
Tc method = LAG Time of conc. (Tc) = 100.65 min
Total precip. = 2.17 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(7.200 x 74) + (34.900 x 74) + (1.400 x 98) + (21.100 x 100)] / 64.600
6
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Q (cfs)
0.00 0.00
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
10.00 10.00
12.00 12.00
Q (cfs)
Time (hrs)
Final Reclamation
Hyd. No. 5 -- 100 Year
Hyd No. 5
- - - - - - - - - - - - - -
......
- - - - - - -\-- - - - - -
- - - - - ----\-- - - - - -
- - - - - - --\ - - - - - -
- - - - - - - -~ - - - - -
.... ,.............
r-,-.....__
- - - - - - - - - - --~ -
J ~
North Hangs
November 2021 H-1
EXHIBIT H WILDLIFE INFORMATION
1. Introduction
Given the location of the site 1 mile southwest of Silt, Colorado, with sand and gravel pits to the
east and west, Interstate 70 to the south, and the Garfield Regional airport to the west, wildlife
habitat fragmentation has already occurred. Colorado Parks & Wildlife (CPW) habitat and range
mapping has been used to develop this section. The CPW will be consulted as part of the permit
process. Detailed discussion of the wildlife found onsite can be found in Appendix H-1: the
Environmental Solutions, Inc. report.
2. Description of Significant Wildlife Resources on the Affected
Land
The affected land is within summer and winter forage areas for bald eagles, but no nests are
present. The permit area is within a wild turkey production area. Black bear overall range is
present on the affected land, which is typical of western Colorado lands. The affected area is
within mule deer ranges and near bird concentration and migration corridors.6
3. Seasonal Use of the Area
All identified significant wildlife resources that have range over the affected area are year
around in their usage.
4. Presence and Estimated Population of Threatened or
Endangered Species
No federally listed threatened and endangered species and/or habitat were identified on the
affected land.
5. Effect of Proposed Operation on Existing Wildlife
Impacts on wildlife use from the proposed project would include direct temporary elimination of
potential habitat within the affected area during mining, and temporary localized displacement
associated with additional noise and lighting from the proposed project. This localized loss of
habitat would not disrupt regional migration or significant movement patterns and would not
threaten the overall health and viability of a species. Nearby lands are also disturbed for
6 https://cpw.state.co.us/learn/Pages/KMZ-Maps.aspx
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industrial uses, and as such the North Hangs Mine disturbance will not be of a significant impact
on area wildlife habitat.
The affected area will be fully reclaimed at the conclusion of mining which will restore some
degree of wildlife habitat over time. Transformation of the bulk of the irrigated fields onsite into a
groundwater lake will be permanent change in overall habitat.
6. Impacts to fish
Mining will not take place in any water ways or natural lakes. Surface water controls will protect
offsite drainages and fish habitats from sediment discharges.
WSM will not stock the reclaimed lake with non-native species at any time.
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Appendix H-1 Wildlife and Vegetation Report
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SEE GARFIELD COUNTY SUP APPENDIX 2
North Hangs
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EXHIBIT I SOILS INFORMATION
1. General
A soil report was generated using the United States Department of Agriculture’s NRCS Web
Soil Survey (WSS)7 and is included in this exhibit as Appendix I-1. The WSS provides soil data
and information produced by the National Cooperative Soil Survey. The majority of the site
(89.6%) is split between three soil types, Wann, Halaquepts, and Torrifluvents (see Map C-1).
Each of these primary soil types is described on the following pages.
In addition to the Web Soil Survey, a site-specific soil analysis was conducted by Kumar and
Associates. This report is attached as Appendix I-2. It confirms the generally three-foot depth of
topsoil on the site
2. Suitability for Reclamation Revegetation
All three soil types provide an average of 18 inches of suitable material for revegetation. All
three soils are listed as class VII without irrigation. Class VII are not suitable for cultivation and
are restricted to grazing by domestic animals or wildlife; all are listed as climatically limited soils.
3. Soil Type Descriptions
72 - Wann sandy loam, 1 to 3 percent slopes
Map Unit Setting
National map unit symbol: jnzc
Elevation: 5,000 to 6,500 feet
Farmland classification: Prime farmland if irrigated and reclaimed of excess salts and sodium
Map Unit Composition
Wann and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Wann
Setting
Landform:Terraces, valley floors
Landform position (three-dimensional):Tread
Down-slope shape:Linear, convex
Across-slope shape:Linear, convex
Parent material:Alluvium derived from sandstone and shale
Typical profile
H1 - 0 to 8 inches: sandy loam
H2 - 8 to 60 inches: fine sandy loam, sandy loam, coarse sandy loam
H2 - 8 to 60 inches:
H2 - 8 to 60 inches:
Properties and qualities
7 https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm.
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Slope:1 to 3 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Poorly drained
Runoff class: Very low
Capacity of the most limiting layer to transmit water (Ksat):High (2.00 to 6.00 in/hr)
Depth to water table:About 0 inches
Frequency of flooding:OccasionalNone
Frequency of ponding:None
Calcium carbonate, maximum content:10 percent
Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
Available water capacity:Very high (about 26.3 inches)
Interpretive groups
Land capability classification (irrigated): 4w
Land capability classification (nonirrigated): 6w
Hydrologic Soil Group: A/D
Ecological site: R048AY265CO - Salt Meadow
Hydric soil rating: Yes
Custom Soil Resource Report 18
Minor Components
Torrifluvents
Percent of map unit:5 percent
Hydric soil rating: No
Kim
Percent of map unit:5 percent
Hydric soil rating: No
Arvada
Percent of map unit:5 percent
Hydric soil rating: No
27 - Halaquepts, nearly level
Map Unit Setting
National map unit symbol: jnxr
Elevation: 5,400 to 7,400 feet
Frost-free period: 101 to 135 days
Farmland classification: Not prime farmland
Map Unit Composition
Halaquepts, nearly level, and similar soils:85 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Halaquepts, Nearly Level
Setting
Landform:Terraces, fans, valleys
Landform position (three-dimensional):Tread
Down-slope shape:Convex, linear
Across-slope shape:Convex, linear
Parent material:Alluvium
Typical profile
H1 - 0 to 8 inches: clay loam
H2 - 8 to 24 inches: loam
H3 - 24 to 60 inches: stratified very gravelly cobbly sand
Properties and qualities
Slope:0 to 6 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Poorly drained
Runoff class: Medium
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North Hangs
November 2021 I-3
Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20 to 0.60 in/hr)
Depth to water table:About 0 inches
Frequency of flooding:OccasionalNone
Frequency of ponding:None
Calcium carbonate, maximum content:10 percent
Gypsum, maximum content:5 percent
Maximum salinity:Moderately saline to strongly saline (8.0 to 16.0 mmhos/cm)
Sodium adsorption ratio, maximum:30.0
Available water capacity:Low (about 3.9 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6w
Hydrologic Soil Group: C/D
Hydric soil rating: Yes
65 - Torrifluvents, nearly level
Map Unit Setting
National map unit symbol: jnz3
Custom Soil Resource Report 16
Elevation: 5,000 to 7,000 feet
Mean annual precipitation: 12 to 15 inches
Mean annual air temperature: 46 to 48 degrees F
Frost-free period: 90 to 120 days
Farmland classification: Not prime farmland
Map Unit Composition
Torrifluvents and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Torrifluvents
Setting
Landform:Distributaries, rivers, flood plains
Down-slope shape:Linear, convex
Across-slope shape:Linear, convex
Parent material:Alluvium
Typical profile
H1 - 0 to 36 inches: loam
H2 - 36 to 60 inches: sand
Properties and qualities
Slope:0 to 6 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Moderately well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high (0.60 to 2.00
in/hr)
Depth to water table:About 12 to 36 inches
Frequency of flooding:OccasionalNone
Frequency of ponding:None
Calcium carbonate, maximum content:5 percent
Gypsum, maximum content:1 percent
Maximum salinity:Very slightly saline to moderately saline (2.0 to 8.0 mmhos/cm)
Sodium adsorption ratio, maximum:2.0
Available water capacity:Moderate (about 7.6 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 7w
II Lewicki & Associates
North Hangs
November 2021 I-4
Hydrologic Soil Group: C
Hydric soil rating: No
Minor Components
Wann
Percent of map unit:10 percent
Landform:Terraces
Hydric soil rating: Yes
Fluvaquents
Percent of map unit:5 percent
Landform:Marshes
Hydric soil rating: Yes
II Lewicki & Associates
North Hangs
November 2021
Appendix I-1 NRCS Web Soil Survey
II Lewicki & Associates
United States
Department of
Agriculture
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
Rifle Area, Colorado,
Parts of Garfield and
Mesa Counties
North Hangs Pit
Natural
Resources
Conservation
Service
November 30, 2020
USDA
~
NRCS
Preface
Soil surveys contain information that affects land use planning in survey areas.
They highlight soil limitations that affect various land uses and provide information
about the properties of the soils in the survey areas. Soil surveys are designed for
many different users, including farmers, ranchers, foresters, agronomists, urban
planners, community officials, engineers, developers, builders, and home buyers.
Also, conservationists, teachers, students, and specialists in recreation, waste
disposal, and pollution control can use the surveys to help them understand,
protect, or enhance the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil
properties that are used in making various land use or land treatment decisions.
The information is intended to help the land users identify and reduce the effects of
soil limitations on various land uses. The landowner or user is responsible for
identifying and complying with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some
cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/
portal/nrcs/main/soils/health/) and certain conservation and engineering
applications. For more detailed information, contact your local USDA Service Center
(https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil
Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/?
cid=nrcs142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as
septic tank absorption fields. A high water table makes a soil poorly suited to
basements or underground installations.
The National Cooperative Soil Survey is a joint effort of the United States
Department of Agriculture and other Federal agencies, State agencies including the
Agricultural Experiment Stations, and local agencies. The Natural Resources
Conservation Service (NRCS) has leadership for the Federal part of the National
Cooperative Soil Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, age, disability,
and where applicable, sex, marital status, familial status, parental status, religion,
sexual orientation, genetic information, political beliefs, reprisal, or because all or a
part of an individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities who require
2
alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice
and TDD). To file a complaint of discrimination, write to USDA, Director, Office of
Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or
call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity
provider and employer.
3
Contents
Preface....................................................................................................................2
How Soil Surveys Are Made..................................................................................5
Soil Map..................................................................................................................8
Soil Map................................................................................................................9
Legend................................................................................................................10
Map Unit Legend................................................................................................12
Map Unit Descriptions........................................................................................12
Rifle Area, Colorado, Parts of Garfield and Mesa Counties............................14
3—Arvada loam, 1 to 6 percent slopes.......................................................14
27—Halaquepts, nearly level......................................................................15
40—Kim loam, 3 to 6 percent slopes..........................................................16
65—Torrifluvents, nearly level.....................................................................16
72—Wann sandy loam, 1 to 3 percent slopes.............................................18
73—Water...................................................................................................19
References............................................................................................................20
4
How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous
areas in a specific area. They include a description of the soils and miscellaneous
areas and their location on the landscape and tables that show soil properties and
limitations affecting various uses. Soil scientists observed the steepness, length,
and shape of the slopes; the general pattern of drainage; the kinds of crops and
native plants; and the kinds of bedrock. They observed and described many soil
profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The
profile extends from the surface down into the unconsolidated material in which the
soil formed or from the surface down to bedrock. The unconsolidated material is
devoid of roots and other living organisms and has not been changed by other
biological activity.
Currently, soils are mapped according to the boundaries of major land resource
areas (MLRAs). MLRAs are geographically associated land resource units that
share common characteristics related to physiography, geology, climate, water
resources, soils, biological resources, and land uses (USDA, 2006). Soil survey
areas typically consist of parts of one or more MLRA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that
is related to the geology, landforms, relief, climate, and natural vegetation of the
area. Each kind of soil and miscellaneous area is associated with a particular kind
of landform or with a segment of the landform. By observing the soils and
miscellaneous areas in the survey area and relating their position to specific
segments of the landform, a soil scientist develops a concept, or model, of how they
were formed. Thus, during mapping, this model enables the soil scientist to predict
with a considerable degree of accuracy the kind of soil or miscellaneous area at a
specific location on the landscape.
Commonly, individual soils on the landscape merge into one another as their
characteristics gradually change. To construct an accurate soil map, however, soil
scientists must determine the boundaries between the soils. They can observe only
a limited number of soil profiles. Nevertheless, these observations, supplemented
by an understanding of the soil-vegetation-landscape relationship, are sufficient to
verify predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They
noted soil color, texture, size and shape of soil aggregates, kind and amount of rock
fragments, distribution of plant roots, reaction, and other features that enable them
to identify soils. After describing the soils in the survey area and determining their
properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set of soil
characteristics with precisely defined limits. The classes are used as a basis for
comparison to classify soils systematically. Soil taxonomy, the system of taxonomic
classification used in the United States, is based mainly on the kind and character
of soil properties and the arrangement of horizons within the profile. After the soil
5
scientists classified and named the soils in the survey area, they compared the
individual soils with similar soils in the same taxonomic class in other areas so that
they could confirm data and assemble additional data based on experience and
research.
The objective of soil mapping is not to delineate pure map unit components; the
objective is to separate the landscape into landforms or landform segments that
have similar use and management requirements. Each map unit is defined by a
unique combination of soil components and/or miscellaneous areas in predictable
proportions. Some components may be highly contrasting to the other components
of the map unit. The presence of minor components in a map unit in no way
diminishes the usefulness or accuracy of the data. The delineation of such
landforms and landform segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, onsite
investigation is needed to define and locate the soils and miscellaneous areas.
Soil scientists make many field observations in the process of producing a soil map.
The frequency of observation is dependent upon several factors, including scale of
mapping, intensity of mapping, design of map units, complexity of the landscape,
and experience of the soil scientist. Observations are made to test and refine the
soil-landscape model and predictions and to verify the classification of the soils at
specific locations. Once the soil-landscape model is refined, a significantly smaller
number of measurements of individual soil properties are made and recorded.
These measurements may include field measurements, such as those for color,
depth to bedrock, and texture, and laboratory measurements, such as those for
content of sand, silt, clay, salt, and other components. Properties of each soil
typically vary from one point to another across the landscape.
Observations for map unit components are aggregated to develop ranges of
characteristics for the components. The aggregated values are presented. Direct
measurements do not exist for every property presented for every map unit
component. Values for some properties are estimated from combinations of other
properties.
While a soil survey is in progress, samples of some of the soils in the area generally
are collected for laboratory analyses and for engineering tests. Soil scientists
interpret the data from these analyses and tests as well as the field-observed
characteristics and the soil properties to determine the expected behavior of the
soils under different uses. Interpretations for all of the soils are field tested through
observation of the soils in different uses and under different levels of management.
Some interpretations are modified to fit local conditions, and some new
interpretations are developed to meet local needs. Data are assembled from other
sources, such as research information, production records, and field experience of
specialists. For example, data on crop yields under defined levels of management
are assembled from farm records and from field or plot experiments on the same
kinds of soil.
Predictions about soil behavior are based not only on soil properties but also on
such variables as climate and biological activity. Soil conditions are predictable over
long periods of time, but they are not predictable from year to year. For example,
soil scientists can predict with a fairly high degree of accuracy that a given soil will
have a high water table within certain depths in most years, but they cannot predict
that a high water table will always be at a specific level in the soil on a specific date.
After soil scientists located and identified the significant natural bodies of soil in the
survey area, they drew the boundaries of these bodies on aerial photographs and
Custom Soil Resource Report
6
identified each as a specific map unit. Aerial photographs show trees, buildings,
fields, roads, and rivers, all of which help in locating boundaries accurately.
Custom Soil Resource Report
7
Soil Map
The soil map section includes the soil map for the defined area of interest, a list of
soil map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
8
9
Custom Soil Resource Report
Soil Map
437990043800004380100438020043803004380400438050043806004380700438080043809004379900438000043801004380200438030043804004380500438060043807004380800269600 269700 269800 269900 270000 270100 270200 270300
269600 269700 269800 269900 270000 270100 270200 270300
39° 32' 49'' N 107° 40' 55'' W39° 32' 49'' N107° 40' 22'' W39° 32' 15'' N
107° 40' 55'' W39° 32' 15'' N
107° 40' 22'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 200 400 800 1200
Feet
0 50 100 200 300
Meters
Map Scale: 1:5,130 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and
Mesa Counties
Survey Area Data: Version 13, Jun 5, 2020
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Dec 31, 2009—Oct
12, 2017
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
Custom Soil Resource Report
10
§
□ (I
D lb
~
{j
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~
181
,,,.....,
* +-H
◊ ~
X ~ . .. ~
0 ~
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0
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MAP LEGEND MAP INFORMATION
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Custom Soil Resource Report
11
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
3 Arvada loam, 1 to 6 percent
slopes
5.1 7.8%
27 Halaquepts, nearly level 23.4 35.6%
40 Kim loam, 3 to 6 percent slopes 1.6 2.5%
65 Torrifluvents, nearly level 12.7 19.4%
72 Wann sandy loam, 1 to 3
percent slopes
22.7 34.6%
73 Water 0.1 0.2%
Totals for Area of Interest 65.6 100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions, along
with the maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
Custom Soil Resource Report
12
The presence of minor components in a map unit in no way diminishes the
usefulness or accuracy of the data. The objective of mapping is not to delineate
pure taxonomic classes but rather to separate the landscape into landforms or
landform segments that have similar use and management requirements. The
delineation of such segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, however,
onsite investigation is needed to define and locate the soils and miscellaneous
areas.
An identifying symbol precedes the map unit name in the map unit descriptions.
Each description includes general facts about the unit and gives important soil
properties and qualities.
Soils that have profiles that are almost alike make up a soil series. Except for
differences in texture of the surface layer, all the soils of a series have major
horizons that are similar in composition, thickness, and arrangement.
Soils of one series can differ in texture of the surface layer, slope, stoniness,
salinity, degree of erosion, and other characteristics that affect their use. On the
basis of such differences, a soil series is divided into soil phases. Most of the areas
shown on the detailed soil maps are phases of soil series. The name of a soil phase
commonly indicates a feature that affects use or management. For example, Alpha
silt loam, 0 to 2 percent slopes, is a phase of the Alpha series.
Some map units are made up of two or more major soils or miscellaneous areas.
These map units are complexes, associations, or undifferentiated groups.
A complex consists of two or more soils or miscellaneous areas in such an intricate
pattern or in such small areas that they cannot be shown separately on the maps.
The pattern and proportion of the soils or miscellaneous areas are somewhat similar
in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example.
An association is made up of two or more geographically associated soils or
miscellaneous areas that are shown as one unit on the maps. Because of present
or anticipated uses of the map units in the survey area, it was not considered
practical or necessary to map the soils or miscellaneous areas separately. The
pattern and relative proportion of the soils or miscellaneous areas are somewhat
similar. Alpha-Beta association, 0 to 2 percent slopes, is an example.
An undifferentiated group is made up of two or more soils or miscellaneous areas
that could be mapped individually but are mapped as one unit because similar
interpretations can be made for use and management. The pattern and proportion
of the soils or miscellaneous areas in a mapped area are not uniform. An area can
be made up of only one of the major soils or miscellaneous areas, or it can be made
up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.
Some surveys include miscellaneous areas. Such areas have little or no soil
material and support little or no vegetation. Rock outcrop is an example.
Custom Soil Resource Report
13
Rifle Area, Colorado, Parts of Garfield and Mesa Counties
3—Arvada loam, 1 to 6 percent slopes
Map Unit Setting
National map unit symbol: jnxv
Elevation: 5,100 to 6,200 feet
Farmland classification: Not prime farmland
Map Unit Composition
Arvada and similar soils:80 percent
Minor components:5 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Arvada
Setting
Landform:Terraces, fans
Landform position (three-dimensional):Tread
Down-slope shape:Convex, linear
Across-slope shape:Convex, linear
Parent material:Highly saline alluvium derived from sandstone and shale
Typical profile
H1 - 0 to 3 inches: loam
H2 - 3 to 17 inches: silty clay loam
H3 - 17 to 60 inches: silty clay loam
Properties and qualities
Slope:1 to 6 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: High
Capacity of the most limiting layer to transmit water (Ksat):Moderately low to
moderately high (0.06 to 0.20 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:10 percent
Gypsum, maximum content:2 percent
Maximum salinity:Slightly saline to strongly saline (4.0 to 16.0 mmhos/cm)
Sodium adsorption ratio, maximum:30.0
Available water capacity:Moderate (about 8.0 inches)
Interpretive groups
Land capability classification (irrigated): 7s
Land capability classification (nonirrigated): 7s
Hydrologic Soil Group: C
Ecological site: R048AY261CO - Salt Flats
Hydric soil rating: No
Minor Components
Wann
Percent of map unit:5 percent
Landform:Terraces
Custom Soil Resource Report
14
Landform position (three-dimensional):Tread
Hydric soil rating: Yes
27—Halaquepts, nearly level
Map Unit Setting
National map unit symbol: jnxr
Elevation: 5,400 to 7,400 feet
Frost-free period: 101 to 135 days
Farmland classification: Not prime farmland
Map Unit Composition
Halaquepts, nearly level, and similar soils:85 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Halaquepts, Nearly Level
Setting
Landform:Terraces, fans, valleys
Landform position (three-dimensional):Tread
Down-slope shape:Convex, linear
Across-slope shape:Convex, linear
Parent material:Alluvium
Typical profile
H1 - 0 to 8 inches: clay loam
H2 - 8 to 24 inches: loam
H3 - 24 to 60 inches: stratified very gravelly cobbly sand
Properties and qualities
Slope:0 to 6 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Poorly drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20
to 0.60 in/hr)
Depth to water table:About 0 inches
Frequency of flooding:OccasionalNone
Frequency of ponding:None
Calcium carbonate, maximum content:10 percent
Gypsum, maximum content:5 percent
Maximum salinity:Moderately saline to strongly saline (8.0 to 16.0 mmhos/cm)
Sodium adsorption ratio, maximum:30.0
Available water capacity:Low (about 3.9 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6w
Hydrologic Soil Group: C/D
Hydric soil rating: Yes
Custom Soil Resource Report
15
40—Kim loam, 3 to 6 percent slopes
Map Unit Setting
National map unit symbol: jny7
Elevation: 5,000 to 6,000 feet
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Kim and similar soils:85 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Kim
Setting
Landform:Benches, alluvial fans
Down-slope shape:Convex, linear
Across-slope shape:Convex, linear
Parent material:Alluvium derived from sandstone and shale
Typical profile
H1 - 0 to 17 inches: loam
H2 - 17 to 60 inches: loam
Properties and qualities
Slope:3 to 6 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high
(0.60 to 6.00 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:15 percent
Available water capacity:High (about 9.6 inches)
Interpretive groups
Land capability classification (irrigated): 3e
Land capability classification (nonirrigated): 3c
Hydrologic Soil Group: A
Ecological site: R048AY298CO - Rolling Loam
Hydric soil rating: No
65—Torrifluvents, nearly level
Map Unit Setting
National map unit symbol: jnz3
Custom Soil Resource Report
16
Elevation: 5,000 to 7,000 feet
Mean annual precipitation: 12 to 15 inches
Mean annual air temperature: 46 to 48 degrees F
Frost-free period: 90 to 120 days
Farmland classification: Not prime farmland
Map Unit Composition
Torrifluvents and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Torrifluvents
Setting
Landform:Distributaries, rivers, flood plains
Down-slope shape:Linear, convex
Across-slope shape:Linear, convex
Parent material:Alluvium
Typical profile
H1 - 0 to 36 inches: loam
H2 - 36 to 60 inches: sand
Properties and qualities
Slope:0 to 6 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Moderately well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high
(0.60 to 2.00 in/hr)
Depth to water table:About 12 to 36 inches
Frequency of flooding:OccasionalNone
Frequency of ponding:None
Calcium carbonate, maximum content:5 percent
Gypsum, maximum content:1 percent
Maximum salinity:Very slightly saline to moderately saline (2.0 to 8.0 mmhos/cm)
Sodium adsorption ratio, maximum:2.0
Available water capacity:Moderate (about 7.6 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 7w
Hydrologic Soil Group: C
Hydric soil rating: No
Minor Components
Wann
Percent of map unit:10 percent
Landform:Terraces
Hydric soil rating: Yes
Fluvaquents
Percent of map unit:5 percent
Landform:Marshes
Hydric soil rating: Yes
Custom Soil Resource Report
17
72—Wann sandy loam, 1 to 3 percent slopes
Map Unit Setting
National map unit symbol: jnzc
Elevation: 5,000 to 6,500 feet
Farmland classification: Prime farmland if irrigated and reclaimed of excess salts
and sodium
Map Unit Composition
Wann and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Wann
Setting
Landform:Terraces, valley floors
Landform position (three-dimensional):Tread
Down-slope shape:Linear, convex
Across-slope shape:Linear, convex
Parent material:Alluvium derived from sandstone and shale
Typical profile
H1 - 0 to 8 inches: sandy loam
H2 - 8 to 60 inches: fine sandy loam, sandy loam, coarse sandy loam
H2 - 8 to 60 inches:
H2 - 8 to 60 inches:
Properties and qualities
Slope:1 to 3 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Poorly drained
Runoff class: Very low
Capacity of the most limiting layer to transmit water (Ksat):High (2.00 to 6.00
in/hr)
Depth to water table:About 0 inches
Frequency of flooding:OccasionalNone
Frequency of ponding:None
Calcium carbonate, maximum content:10 percent
Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
Available water capacity:Very high (about 26.3 inches)
Interpretive groups
Land capability classification (irrigated): 4w
Land capability classification (nonirrigated): 6w
Hydrologic Soil Group: A/D
Ecological site: R048AY265CO - Salt Meadow
Hydric soil rating: Yes
Custom Soil Resource Report
18
Minor Components
Torrifluvents
Percent of map unit:5 percent
Hydric soil rating: No
Kim
Percent of map unit:5 percent
Hydric soil rating: No
Arvada
Percent of map unit:5 percent
Hydric soil rating: No
73—Water
Map Unit Composition
Water:100 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Custom Soil Resource Report
19
References
American Association of State Highway and Transportation Officials (AASHTO).
2004. Standard specifications for transportation materials and methods of sampling
and testing. 24th edition.
American Society for Testing and Materials (ASTM). 2005. Standard classification of
soils for engineering purposes. ASTM Standard D2487-00.
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of
wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife
Service FWS/OBS-79/31.
Federal Register. July 13, 1994. Changes in hydric soils of the United States.
Federal Register. September 18, 2002. Hydric soils of the United States.
Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric
soils in the United States.
National Research Council. 1995. Wetlands: Characteristics and boundaries.
Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service.
U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/national/soils/?cid=nrcs142p2_054262
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for
making and interpreting soil surveys. 2nd edition. Natural Resources Conservation
Service, U.S. Department of Agriculture Handbook 436. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577
Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of
Agriculture, Natural Resources Conservation Service. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580
Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and
Delaware Department of Natural Resources and Environmental Control, Wetlands
Section.
United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of
Engineers wetlands delineation manual. Waterways Experiment Station Technical
Report Y-87-1.
United States Department of Agriculture, Natural Resources Conservation Service.
National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/
home/?cid=nrcs142p2_053374
United States Department of Agriculture, Natural Resources Conservation Service.
National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/
detail/national/landuse/rangepasture/?cid=stelprdb1043084
20
United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/soils/scientists/?cid=nrcs142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service.
2006. Land resource regions and major land resource areas of the United States,
the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook
296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?
cid=nrcs142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land
capability classification. U.S. Department of Agriculture Handbook 210. http://
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf
Custom Soil Resource Report
21
North Hangs
November 2021
Appendix I-2 Kumar & Associates Report
II Lewicki & Associates
SEE GARFIELD COUNTY SUP APPENDIX 3
North Hangs
November 2021 J-1
EXHIBIT J VEGETATION INFORMATION
1. Existing Vegetation Community
The study area contains a mixture of grass-forb herbaceous vegetation in the irrigated pastures.
Non-irrigated areas range from mature cottonwood galleries with shrubby midstory and sparse
herbaceous understories to very dry, sparse shrublands and grassy areas. Flood irrigation has
been heavily applied on the pasture areas, resulting in some areas dominated by hydrophytes
along and below the ditches. Irrigation has typically begun in mid-April and does not shut off
until October in most years. A detailed vegetation discussion can be found in the Environmental
Solutions report in Appendix H-1.
Figure J-1 Typical rangeland vegetation found in permit area.
II Lewicki & Associates
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November 2021 J-2
Figure J-1 Typical mature cottonwood galleries with shrubby midstory
2. Estimated Carrying Capacity
The final land use for the site will be a lake with surrounding rangeland. Since the lake is the
vast majority of the site area, the rangeland is not anticipated to be used for grazing.
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North Hangs
November 2021 J-3
Appendix J-1 Wetland Report
II Lewicki & Associates
SEE GARFIELD COUNTY SUP APPENDIX 7
North Hangs
November 2021 K-1
EXHIBIT K CLIMATE INFORMATION
1. General Information
The proposed North Hangs Mine is located 1 mile southwest of Silt, Colorado at an elevation of
approximately 5450 feet. The area is classified as Warm-summer humid continental climate
(Dfb) under the Koppen Classification system. This climate classification is dominated by long
warm summers and no significant precipitation difference between seasons. Table K-1 shows a
summary of the climate for this area based on records from 1901 to 2005.
Table K-1 Climate Data of Garfield Regional Airport, Rifle, Colorado, approximately 2
miles southwest of the North Hangs Mine (source: https://wrcc.dri.edu/cgi-
bin/cliMAIN.pl?corifl).
Average Temperature (F) Average Precipitation (in)
Maximum Minimum Total precip. Total snow
January 36.8 9.4 0.86 11.1
February 43.8 16.5 0.77 7.7
March 53.7 24.2 0.95 3.7
April 64.2 31.4 1.02 0.8
May 74.0 38.7 1.00 0
June 84.0 45.2 0.73 0
July 90.2 52.0 1.02 0
August 87.6 50.4 1.13 0
September 79.4 41.4 1.11 0
October 67.3 31.1 1.20 0.5
November 51.4 21.3 0.89 3.8
December 39.4 12.4 0.93 11.1
Yearly (avg) 64.3 31.2 11.61 (0.97) 38.6 (3.21)
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November 2021 L-1
EXHIBIT L RECLAMATION COSTS
In accordance with Rule 6.4.12, this exhibit outlines the different reclamation scenarios that will
inform the bond calculation conducted by Division staff. North Hangs Mine will have a phased
bond: Phase 1 will cover reclaiming the site assuming mining does not take place in the footprint
of any wetlands, the footprint of the Bernudy Ditch, or within 250 feet of the Colorado River.
Prior to initiating any of those three activities, the operator/applicant will post the necessary
bond for Phase 2. Each bond calculation is outlined below.
1. Phase 1
Reclamation of the Phase 1 mining scenario will create three lakes, an industrial/commercial
area, and rangeland. It will involve the removal of berms and pit pumping infrastructure. It is
assumed that mining will be undertaken last in the north pit of Phase 1. The maximum highwall
that will be in operation at any given time will be 1000 feet long. This maximum active highwall
is also 25 feet tall, based on the anticipated maximum depth of mining. To reclaim it will require
a dozer push of the near vertical active highwall to an overall slope of 2H:1V, and then
backfilling and grading to 5H:1V, 3H:1V, and 2H:1V as shown on the Map C-4 cross sections
and in Figure L-1 below.
Figure L-1. Highwall Reclamation Cross Section (Typical)
All other backfilling and grading of slopes will be completed by this point. The north pit will need
dewatering to accomplish this grading and final topsoiling and revegetation. Based on the 5H:1V
Final Reclaimed
Slopes
Active Mining
Highwall
Mining Slope
(knocked down)
Lake level
II Lewicki & Associates
North Hangs
November 2021 L-2
slopes above the water line, the maximum Phase 1 topsoil and reseeding area can be
calculated. Table L-1 shows all quantities needed for Phase 1 reclamation along with a total
cost for reclaiming at the end of Phase 1.
Reclamation of the Phase 2 mining scenario will create one lake, an industrial/commercial area,
and rangeland. It will involve the removal of berms and pit pumping infrastructure. It is assumed
that mining will be undertaken last along the northern end of the mining pit. The maximum
highwall that will be in operation at any given time will be 1000 feet long. This maximum active
highwall is also 25 feet tall, based on the anticipated maximum depth of mining. To reclaim it will
require a dozer push of the near vertical active highwall to an overall slope of 2H:1V, and then
backfilling and grading to 5H:1V, 3H:1V, and 2H:1V as shown on the Map C-4 cross sections
and in Figure L-1 above.
All other backfilling and grading of slopes will be completed by this point. The north pit will need
dewatering to accomplish this grading and final topsoiling and revegetation. Based on the 5H:1V
slopes above the water line, the maximum Phase 2 topsoil and reseeding area can be
calculated. Table L-2 shows all quantities needed for Phase 2 reclamation along with a total
cost for reclaiming at the end of Phase 2.
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North Hangs
November 2021 L-3
Table L-1. Phase 1 Reclamation Task and Cost Estimate
Description Material
Quantity
Unit Unit Cost Cost Removal of office, scale house, and scale N/A N/A $5000 $5,000 Pit dewatering for a 7.3 acre lake 21 feet deep. 153.3 Acre-ft $105 $16,097 Highwall backfilling from mining to final condition. 1000 SQ. FT. over 1000 FT. 37,000 CY $1.50 $55,500 Topsoiling to 18 inches deep the maximum disturbance area of 25 acres. 60,500 CY $1.50 $90,750 Discing of topsoil to a depth of 18 inches over 25 acres. 25 acres $105 $2,625 Seeding of 25 acre disturbance area 25 acres $400 $10,000 Mulching and crimping of mulch over 25 acre disturbance area 25 acres $850 $21,250 Weed control management for two years on 25 acres 25 acres $220 $5,500 Subtotal $206,722 DRMS cost (28%) $57,882
Total $264,604
Table L-2. Phase 2 Reclamation Task and Cost Estimate
Description Material
Quantity
Unit Unit Cost Cost Removal of office, scale house, and scale N/A N/A $5000 $5,000 Pit dewatering for a 25 acre lake 21 feet deep. 525 Acre-ft $105 $55,125 Highwall backfilling from mining to final condition. 1000 SQ. FT. over 1000 FT. 37,000 CY $1.50 $55,500 Topsoiling to 18 inches deep the maximum disturbance area of 25 acres. 60,500 CY $1.50 $90,750 Discing of topsoil to a depth of 18 inches over 25 acres. 25 acres $105 $2,625 Seeding of 25 acre disturbance area 25 acres $400 $10,000 Mulching and crimping of mulch over 25 acre disturbance area 25 acres $850 $21,250 Weed control management for two years on 25 acres 25 acres $220 $5,500 Subtotal $245,750 DRMS cost (28%) $68,810
Total $314,560
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November 2021 M-1
EXHIBIT M OTHER PERMITS REQUIRED
The following permits are necessary for the full operation of the North Hangs Mine
1. Garfield County Land Use Change Permit.
2. Colorado Air Pollution Control Division Fugitive Dust Permit and Air Pollution
Emission Notice (APEN)
3. Water Quality Control Commission Discharge Permit
4. US Army Corps of Engineers permits (as needed)
5. Substitute Water Supply Plan (Phase 1)
6. Augmentation Plan (Phase 2)
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North Hangs
November 2021 N-1
EXHIBIT N RIGHT OF ENTRY
As shown on the documents, the surface owners of record of the property which will be mined is
North Hangs Ranch LLC. A right of entry agreement is in place for the North Hangs Ranch LLC
land and is also attached.
North Hangs Ranch LLC
950 Smile Way
York Pa 17404
II Lewicki & Associates
North Hangs
November 2021 O-1
EXHIBIT O OWNERS OF AFFECTED LAND
AND MINERAL TO BE MINED
The owner(s) of record of affected land (surface area) and owners of substance to be mined is
North Hangs Ranch LLC.
North Hangs Ranch LLC
950 Smile Way
York, Pennsylvania 17404
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North Hangs
November 2021 P-1
EXHIBIT P MUNICIPALITIES WITHIN TWO MILES
The North Hangs Mine is located approximately 1 mile southwest of Silt, Colorado, a statutory
town in Garfield County.
Town of Silt
231 N. 7th Street
PO Box 70
Silt, Colorado 81652
II Lewicki & Associates
North Hangs
November 2021 Q-1
EXHIBIT Q PROOF OF MAILING OF NOTICES TO
THE BOARD OF COUNTY COMMISSIONERS AND
SOIL CONSERVATION DISTRICT
Notices were filed with the Garfield County Board of Commissioners and the South Side
Conservation District in support of this permit application.
Board of County Commissioners
108 8th Street, Suite 101
Glenwood Springs, Colorado 81601
Bookcliff, Mount Sopris and South Side Conservation Districts
258 Center Dr
Glenwood Springs, CO 81601
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North Hangs
November 2021 R-1
EXHIBIT R PROOF OF FILING WITH COUNTY
CLERK
Garfield County Clerk and Recorder
109 8th Street, Suite 200
Glenwood Springs, Colorado 81601
II Lewicki & Associates
North Hangs
November 2021 S-1
EXHIBIT S PERMANENT MAN-MADE
STRUCTURES
The following is an inventory of man-made structures within 200 feet of the affected area. All of
these structures are shown on Map C-1. Landowner boundaries can also be found on the Map
C-1. Proof of delivery of structure agreements is attached to this exhibit. In the event that a
structure agreement is unobtainable, we will defer to the Geotechnical Stability Exhibit which
indicates that all structures will be protected.
Table S-1. Permanent Structures within 200’ of the Affected Area
Owner Structures General Location Colorado Dept of Transportation 2829 W. Howard Pl. Denver, CO 80204
Interstate 70; Irrig. Ditches; Fence South
Garfield County Road and Bridge District 2-3 facility 0298 County Road 333A Rifle, CO 81650
County Road 346 South
Grand River LLC Bernudy Ditch & associated structures Traverses permit area east to west Holy Cross Energy 3799 Highway 82 PO Box 2150 Glenwood Springs, CO 81602
Gas lines South
Shidelerosa LLLP 1411 County Road 316 Silt, CO 81652 Fence West
II Lewicki & Associates
North Hangs
November 2021 RULE-1
RULE 1.6.2(1)(B)
Prior to the submittal of the application, a sign was erected at the entrance to the site which
contained all the required information regarding Rule 1.6.2(1)(b).
Please see attached sign certification.
II Lewicki & Associates
North Hangs
November 2021 GS-1
GEOTECHNICAL STABILITY EXHIBIT
There are no known geologic hazards on the proposed site. Based on a slope stability analysis,
buildings or other structures within 200’ of the North Hangs Mine affected area will not be
affected by mining excavation. Sufficient buffers will be maintained to neighboring property
lines. Exhibit C maps shows these buffers. Map C-4 shows the mining and reclamation slopes
of the mine in cross section. A single cross section of the mining and reclamation slopes was
analyzed for slope stability: the portion closest to the Colorado River in Phase 2.
The material properties are derived from Table 2.5 in the SME Mining Reference Handbook 8, as
there is no site-specific sample data of the material available. Therefore, all materials are
matched to a classification from this table that best matches the materials in terms of
description. The native alluvial material is best classified as sand and gravel with a mixed grain
size. From the SME table, sand and gravel with a mixed grain size has an internal angle of
friction of 45 degrees and no cohesion. An average of 18 inches of topsoil and two feet of
overburden lies atop of the sand and gravel. These are described in the soil surveys in Exhibit I
as sandy loam. This best matches the description for loose sand, mixed grain size from the
SME table, which has an internal angle of friction of 34 degrees and no cohesion. This material
will be used as backfill.
The slope analyzed was modelled in three scenarios:
1. Maximum mining slopes with the groundwater table at natural level.
2. Maximum mining slopes after rapid draw-down of the groundwater table.
3. Final reclaimed slopes, assuming 100% backfill from mining slopes.
Bishop’s Method of Slices was the slope stability calculation methodology uses and the software
GALENA was used to model slopes and calculate the factor of safety. The location of slopes
modelled in GALENA can be seen on Figure GS-1. This location was selected for the proximity
of the Colorado River to the slopes. Table GS-1 lists the slopes and their respective factors of
safety. The minimum factor of safety for operations of this type, according to CDRMS technical
guidance, is 1.5. The lowest factor of safety calculated at the North Hangs Mine is 1.9.
GALENA data tables and analysis result figures are attached as Appendix GS-1.
8 Original source: Houk and Bray 1977
II Lewicki & Associates
North Hangs
November 2021 GS-2
Figure GS-1. Location of Slope Stability Analysis (Phase 2 Mining Plan Shown)
_ __-,
••
•• ... ·•• 11.
I
. ~2' e 5~B0'
I
I
•• I
____.....__c \
j
I
---·
•
•
"'-·m"'" ./"'·.--~~
. . ;J ~
• ••• 1'
-
II Lewicki & A . ssoc,ates
North Hangs
November 2021 GS-3
Table GS-1. Factors of Safety for Slope Stability
Scenario Lowest Factor of
Safety Maximum mining slopes with the groundwater table at natural level. 1.9 Maximum mining slopes after rapid draw-down of the groundwater table. 1.9 Final reclaimed slopes, assuming 100% backfill from mining slopes 2.8
The slope stability analysis in this permit has been prepared according to appropriate
engineering standards and practices.
Ben Langenfeld, P.E.
P.E.# 0047151
II Lewicki & Associates
North Hangs
November 2021 GS-4
APPENDIX GS-1 GALENA INFORMATION
II Lewicki & Associates
GALENA Version 7.2
Project North Hangs Mine
Cross Section 1 - Mining Slope with Groundwater
File:E:\Work\Dropbox (GLA)\Western Slope Agg\North Hangs\Soils Geology\GALENA\North Hangs Mine Slope Stability.gmf
Edited:
Processed:
16 Jun 2021
16 Jun 2021
Greg Lewicki and AssociatesLicensed to:
Analysis
Results
1
Multiple Stability Analysis
Bishop Simplified
Circular
Method:
Surface:
Critical Factor of Safety: 1.91
Material Keys
1: Sand and gravel, mixed grain size
2: Loose sand, mixed grain size
0 50 100 150 200 250 300 350
5250
5300
5350
5400
5450
5500
I I I I I I I I
-
-
I I I I I I I I
_;:+( Greg J..c,wicki Aod As1od au1, l'l,LC
'-"''"'H , __ ,_
GALENA Version 7.2
Project North Hangs Mine
Cross Section 1 - Mining Slope with Rapid Drawdown
File:E:\Work\Dropbox (GLA)\Western Slope Agg\North Hangs\Soils Geology\GALENA\North Hangs Mine Slope Stability.gmf
Edited:
Processed:
16 Jun 2021
16 Jun 2021
Greg Lewicki and AssociatesLicensed to:
Analysis
Results
2
Multiple Stability Analysis
Bishop Simplified
Circular
Method:
Surface:
Critical Factor of Safety: 1.91
Material Keys
1: Sand and gravel, mixed grain size
2: Loose sand, mixed grain size
0 50 100 150 200 250 300 350
5250
5300
5350
5400
5450
5500
I T T T I I I I
.. •-.-.-.-.:::::::.:::::::-,.,.__.-_,-_,::::::::::::-,_._,--,-_,_,--_,:::::1t:::::•__,_,--... -__....,-,_-,_-H-:::.:~ ...
"'11-------+-----------•
-
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_;:+( Greg J..c,wicki Aod As1od au1, l'l,LC
., "''"'~• ,_,,.,-,,,,.,._...,,
GALENA Version 7.2
Project North Hangs Mine
Cross Section 1 - Reclaimed Slope with Groundwater
File:E:\Work\Dropbox (GLA)\Western Slope Agg\North Hangs\Soils Geology\GALENA\North Hangs Mine Slope Stability.gmf
Edited:
Processed:
16 Jun 2021
16 Jun 2021
Greg Lewicki and AssociatesLicensed to:
Analysis
Results
3
Multiple Stability Analysis
Bishop Simplified
Circular
Method:
Surface:
Critical Factor of Safety: 2.78
Material Keys
1: Sand and gravel, mixed grain size
2: Loose sand, mixed grain size
0 50 100 150 200 250 300 350
5250
5300
5350
5400
5450
5500
I I I I I I I I
.
-
-
I I I I I I I I
_;:+( Greg J..c,wicki Aod As1od au1, l'l,LC
'-"''"'H , __ ,_
GALENA 7.2 Analysis Results
Version: 7.20.1.01 Licensee: Greg Lewicki and Associates
——————————————————————————————————————————————————————————————————————————————————————
Project: North Hangs Mine
File: E:\Work\Dropbox (GLA)\Western Slope Agg\North Hangs\Soils Geology\GALENA\North Hangs Mine
Slope Stability.gmf
Processed: 16 Jun 2021 11:46:25
——————————————————————————————————————————————————————————————————————————————————————
1. Analysis 1 - Cross Section 1 - Mining Slope with Groundwater
Material Properties (2 materials)
-------------------
Material: 1 (Mohr-Coulomb Isotropic) - Sand and gravel, mixed grain size
Cohesion Phi UnitWeight Ru
0.00 45.0 110.00 Auto
Material: 2 (Mohr-Coulomb Isotropic) - Loose sand, mixed grain size
Cohesion Phi UnitWeight Ru
0.00 34.0 99.00 Auto
Water Properties
----------------
Unit weight of water: 62.400
Unit weight of water/medium above ground: 62.400
Material Profiles (2 profiles)
-----------------
Profile: 1 (3 points) Material beneath: 2 - Loose sand, mixed grain size
0.00 5389.52
204.04 5391.91
348.51 5390.21
Profile: 2 (3 points) Material beneath: 1 - Sand and gravel, mixed grain size
0.04 5386.02
204.04 5388.41
348.47 5386.71
Slope Surface (4 points)
-------------
0.00 5389.52
204.04 5391.91
256.59 5370.00
348.51 5370.00
Phreatic Surface (2 points)
----------------
0.00 5385.00
400.00 5385.00
Failure Surface
---------------
Initial circular surface for critical search defined by: XL,XR,R
Intersects: XL: 176.40 YL: 5391.59 XR: 255.30 YR: 5370.54
Centre: XC: 279.42 YC: 5619.37 Radius: R: 250.00
Variable Restraints
-------------------
Parameter descriptor: XL XR R
Range of variation: 75.00 75.00 25.00
Trial positions within range: 25 25 25
- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
RESULTS: Analysis 1 - Cross Section 1 - Mining Slope with Groundwater
Bishop Simplified Method of Analysis - Circular Failure Surface
---------------------------------------------------------------
Critical Failure Surface Search using Multiple Circle Generation Techniques
Initial failure surface approximation - Factor of Safety: 3.349
Analysis Summary
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
There were: 10627 successful analyses from a total of 15625 trial failure surfaces
4998 analyses terminated due to unacceptable geometry
Critical (minimum) Factor of Safety: 1.91
——————————————————————————————————————————
Results Summary - Lowest 99 Factor of Safety circles
----------------------------------------------------
Circle X-Left Y-Left X-Right Y-Right X-Centre Y-Centre Radius FoS
1 204.52 5391.71 217.80 5386.17 311.34 5629.21 260.42 1.909 <-- Critical Surface
2 204.52 5391.71 217.80 5386.17 310.94 5628.25 259.38 1.909
3 204.52 5391.71 217.80 5386.17 311.75 5630.17 261.46 1.909
4 204.52 5391.71 217.80 5386.17 312.15 5631.13 262.50 1.909
5 204.52 5391.71 217.80 5386.17 310.54 5627.28 258.33 1.910
6 204.52 5391.71 217.80 5386.17 308.54 5622.48 253.12 1.910
7 204.52 5391.71 217.80 5386.17 309.34 5624.40 255.21 1.910
8 204.52 5391.71 217.80 5386.17 309.74 5625.36 256.25 1.910
9 204.52 5391.71 217.80 5386.17 308.94 5623.44 254.17 1.910
10 204.52 5391.71 217.80 5386.17 310.14 5626.32 257.29 1.910
11 204.52 5391.71 217.80 5386.17 306.93 5618.63 248.96 1.910
12 204.52 5391.71 217.80 5386.17 308.14 5621.51 252.08 1.910
13 204.52 5391.71 217.80 5386.17 307.33 5619.59 250.00 1.911
14 204.52 5391.71 217.80 5386.17 305.73 5615.74 245.83 1.911
15 204.52 5391.71 217.80 5386.17 307.74 5620.55 251.04 1.911
16 204.52 5391.71 217.80 5386.17 304.93 5613.82 243.75 1.911
17 204.52 5391.71 217.80 5386.17 306.53 5617.67 247.92 1.911
18 204.52 5391.71 217.80 5386.17 306.13 5616.70 246.88 1.911
19 204.52 5391.71 217.80 5386.17 305.33 5614.78 244.79 1.911
20 204.52 5391.71 217.80 5386.17 304.13 5611.90 241.67 1.911
21 204.52 5391.71 217.80 5386.17 303.72 5610.93 240.62 1.911
22 204.52 5391.71 217.80 5386.17 304.53 5612.86 242.71 1.911
23 204.52 5391.71 217.80 5386.17 303.32 5609.97 239.58 1.912
24 204.52 5391.71 217.80 5386.17 302.92 5609.01 238.54 1.912
25 204.52 5391.71 217.80 5386.17 302.52 5608.05 237.50 1.912
26 207.65 5390.40 217.80 5386.17 313.32 5629.56 261.46 2.042
27 207.65 5390.40 217.80 5386.17 312.92 5628.60 260.42 2.042
28 207.65 5390.40 217.80 5386.17 313.72 5630.52 262.50 2.043
29 207.65 5390.40 217.80 5386.17 309.71 5620.90 252.08 2.043
30 207.65 5390.40 217.80 5386.17 310.11 5621.86 253.12 2.043
31 207.65 5390.40 217.80 5386.17 310.51 5622.83 254.17 2.043
32 207.65 5390.40 217.80 5386.17 310.91 5623.79 255.21 2.044
33 207.65 5390.40 217.80 5386.17 312.12 5626.67 258.33 2.044
34 207.65 5390.40 217.80 5386.17 311.72 5625.71 257.29 2.044
35 207.65 5390.40 217.80 5386.17 308.51 5618.02 248.96 2.044
36 207.65 5390.40 217.80 5386.17 311.31 5624.75 256.25 2.044
37 207.65 5390.40 217.80 5386.17 312.52 5627.63 259.38 2.044
38 207.65 5390.40 217.80 5386.17 308.91 5618.98 250.00 2.044
39 207.65 5390.40 217.80 5386.17 307.31 5615.13 245.83 2.044
40 207.65 5390.40 217.80 5386.17 309.31 5619.94 251.04 2.044
41 207.65 5390.40 217.80 5386.17 306.10 5612.25 242.71 2.044
42 207.65 5390.40 217.80 5386.17 308.11 5617.06 247.92 2.044
43 207.65 5390.40 217.80 5386.17 305.70 5611.29 241.67 2.044
44 207.65 5390.40 217.80 5386.17 306.90 5614.17 244.79 2.044
45 207.65 5390.40 217.80 5386.17 304.90 5609.36 239.58 2.044
46 207.65 5390.40 217.80 5386.17 306.50 5613.21 243.75 2.044
47 207.65 5390.40 217.80 5386.17 307.71 5616.09 246.88 2.044
48 207.65 5390.40 217.80 5386.17 305.30 5610.32 240.62 2.045
49 207.65 5390.40 217.80 5386.17 304.50 5608.40 238.54 2.045
50 207.65 5390.40 217.80 5386.17 304.10 5607.44 237.50 2.046
51 204.52 5391.71 220.93 5384.87 313.69 5630.43 262.50 2.056
52 204.52 5391.71 220.93 5384.87 312.88 5628.51 260.42 2.056
53 204.52 5391.71 220.93 5384.87 312.08 5626.59 258.33 2.056
54 204.52 5391.71 220.93 5384.87 310.08 5621.78 253.12 2.056
55 204.52 5391.71 220.93 5384.87 312.48 5627.55 259.38 2.056
56 204.52 5391.71 220.93 5384.87 311.68 5625.62 257.29 2.056
57 204.52 5391.71 220.93 5384.87 310.48 5622.74 254.17 2.056
58 204.52 5391.71 220.93 5384.87 313.28 5629.47 261.46 2.056
59 204.52 5391.71 220.93 5384.87 310.88 5623.70 255.21 2.056
60 204.52 5391.71 220.93 5384.87 309.67 5620.81 252.08 2.056
61 204.52 5391.71 220.93 5384.87 308.47 5617.93 248.96 2.057
62 204.52 5391.71 220.93 5384.87 308.87 5618.89 250.00 2.057
63 204.52 5391.71 220.93 5384.87 308.07 5616.97 247.92 2.057
64 204.52 5391.71 220.93 5384.87 311.28 5624.66 256.25 2.057
65 204.52 5391.71 220.93 5384.87 304.46 5608.31 238.54 2.057
66 204.52 5391.71 220.93 5384.87 306.47 5613.12 243.75 2.057
67 204.52 5391.71 220.93 5384.87 309.27 5619.85 251.04 2.057
68 204.52 5391.71 220.93 5384.87 306.87 5614.08 244.79 2.057
69 204.52 5391.71 220.93 5384.87 307.27 5615.04 245.83 2.057
70 204.52 5391.71 220.93 5384.87 306.06 5612.16 242.71 2.057
71 204.52 5391.71 220.93 5384.87 307.67 5616.00 246.88 2.057
72 204.52 5391.71 220.93 5384.87 305.26 5610.23 240.62 2.057
73 204.52 5391.71 220.93 5384.87 304.06 5607.34 237.50 2.057
74 204.52 5391.71 220.93 5384.87 305.66 5611.19 241.67 2.057
75 204.52 5391.71 220.93 5384.87 304.86 5609.27 239.58 2.057
76 201.40 5391.88 217.80 5386.17 295.48 5635.83 261.46 2.116
77 201.40 5391.88 217.80 5386.17 295.82 5636.81 262.50 2.116
78 201.40 5391.88 217.80 5386.17 295.13 5634.84 260.42 2.116
79 201.40 5391.88 217.80 5386.17 294.79 5633.86 259.38 2.116
80 201.40 5391.88 217.80 5386.17 294.45 5632.87 258.33 2.117
81 201.40 5391.88 217.80 5386.17 294.11 5631.89 257.29 2.117
82 201.40 5391.88 217.80 5386.17 293.76 5630.90 256.25 2.117
83 201.40 5391.88 217.80 5386.17 293.42 5629.92 255.21 2.117
84 201.40 5391.88 217.80 5386.17 293.08 5628.94 254.17 2.117
85 201.40 5391.88 217.80 5386.17 292.74 5627.95 253.12 2.117
86 201.40 5391.88 217.80 5386.17 292.39 5626.97 252.08 2.117
87 201.40 5391.88 217.80 5386.17 292.05 5625.98 251.04 2.117
88 201.40 5391.88 217.80 5386.17 291.37 5624.01 248.96 2.117
89 201.40 5391.88 217.80 5386.17 291.71 5625.00 250.00 2.117
90 201.40 5391.88 217.80 5386.17 290.34 5621.06 245.83 2.117
91 201.40 5391.88 217.80 5386.17 291.02 5623.03 247.92 2.117
92 201.40 5391.88 217.80 5386.17 290.68 5622.04 246.88 2.117
93 201.40 5391.88 217.80 5386.17 290.00 5620.08 244.79 2.118
94 201.40 5391.88 217.80 5386.17 289.65 5619.09 243.75 2.118
95 201.40 5391.88 217.80 5386.17 289.31 5618.11 242.71 2.118
96 201.40 5391.88 217.80 5386.17 288.97 5617.12 241.67 2.118
97 201.40 5391.88 217.80 5386.17 288.63 5616.14 240.62 2.118
98 201.40 5391.88 217.80 5386.17 288.28 5615.15 239.58 2.118
99 201.40 5391.88 217.80 5386.17 287.94 5614.17 238.54 2.118
Critical Failure Surface (circle 1)
------------------------
Intersects: XL: 204.52 YL: 5391.71 XR: 217.80 YR: 5386.17
Centre: XC: 311.34 YC: 5629.21 Radius: R: 260.42
Generated failure surface: (20 points)
204.52 5391.71 205.22 5391.40 205.91 5391.09 206.60 5390.79 207.29 5390.48
207.99 5390.18 208.68 5389.88 209.38 5389.58 210.08 5389.29 210.78 5388.99
211.47 5388.70 212.17 5388.41 212.87 5388.13 213.58 5387.84 214.28 5387.56
214.98 5387.28 215.68 5387.00 216.39 5386.72 217.09 5386.45 217.80 5386.17
Slice Geometry and Properties - Critical Failure Surface (circle 1, 39 slices)
--------------------------------------------------------
Slice X-S ------------------- Base --------------------- PoreWater Normal Test
X-Left Area Angle Width Length Matl Cohesion Phi Weight Force Stress Factor
1 204.52 0.00 24.1 0.35 0.38 2 0.00 34.0 0.17 0.00 0.42 0.95
2 204.87 0.01 24.1 0.35 0.38 2 0.00 34.0 0.55 0.00 1.38 0.95
3 205.22 0.01 24.0 0.35 0.38 2 0.00 34.0 0.90 0.00 2.26 0.95
4 205.56 0.01 24.0 0.35 0.38 2 0.00 34.0 1.22 0.00 3.05 0.95
5 205.91 0.02 23.7 0.35 0.38 2 0.00 34.0 1.52 0.00 3.81 0.95
6 206.25 0.02 23.8 0.35 0.38 2 0.00 34.0 1.81 0.00 4.52 0.95
7 206.60 0.02 23.7 0.35 0.38 2 0.00 34.0 2.08 0.00 5.19 0.95
8 206.95 0.02 23.7 0.35 0.38 2 0.00 34.0 2.33 0.00 5.82 0.95
9 207.29 0.03 23.5 0.35 0.38 2 0.00 34.0 2.55 0.00 6.37 0.95
10 207.64 0.03 23.4 0.35 0.38 2 0.00 34.0 2.77 0.00 6.92 0.95
11 207.99 0.03 23.3 0.35 0.38 2 0.00 34.0 2.94 0.00 7.34 0.95
12 208.34 0.03 23.3 0.35 0.38 2 0.00 34.0 3.13 0.00 7.80 0.95
13 208.68 0.03 23.1 0.35 0.38 2 0.00 34.0 3.26 0.00 8.15 0.94
14 209.03 0.03 23.2 0.35 0.38 2 0.00 34.0 3.40 0.00 8.48 0.94
15 209.38 0.04 23.0 0.35 0.38 2 0.00 34.0 3.49 0.00 8.70 0.94
16 209.73 0.04 22.9 0.35 0.38 2 0.00 34.0 3.59 0.00 8.96 0.94
17 210.08 0.04 22.8 0.35 0.38 2 0.00 34.0 3.64 0.00 9.09 0.94
18 210.43 0.04 22.8 0.35 0.38 2 0.00 34.0 3.69 0.00 9.21 0.94
19 210.78 0.04 22.6 0.35 0.38 2 0.00 34.0 3.72 0.00 9.27 0.94
20 211.12 0.04 22.6 0.35 0.38 2 0.00 34.0 3.70 0.00 9.23 0.94
21 211.47 0.04 22.5 0.35 0.38 2 0.00 34.0 3.69 0.00 9.19 0.94
22 211.82 0.04 22.4 0.35 0.38 2 0.00 34.0 3.65 0.00 9.11 0.94
23 212.17 0.03 22.3 0.25 0.27 2 0.00 34.0 2.58 0.00 8.99 0.94
24 212.42 0.03 22.3 0.25 0.28 1 0.00 45.0 2.71 0.00 8.77 0.89
25 212.68 0.02 22.3 0.20 0.21 1 0.00 45.0 2.16 0.00 9.11 0.89
26 212.87 0.03 22.1 0.35 0.38 1 0.00 45.0 3.79 0.00 8.90 0.89
27 213.22 0.03 22.1 0.35 0.38 1 0.00 45.0 3.65 0.00 8.59 0.89
28 213.58 0.03 22.0 0.35 0.38 1 0.00 45.0 3.49 0.00 8.20 0.89
29 213.93 0.03 22.0 0.35 0.38 1 0.00 45.0 3.30 0.00 7.76 0.89
30 214.28 0.03 21.8 0.35 0.38 1 0.00 45.0 3.10 0.00 7.28 0.89
31 214.63 0.03 21.8 0.35 0.38 1 0.00 45.0 2.87 0.00 6.75 0.89
32 214.98 0.02 21.6 0.35 0.38 1 0.00 45.0 2.63 0.00 6.18 0.89
33 215.33 0.02 21.6 0.35 0.38 1 0.00 45.0 2.34 0.00 5.51 0.89
34 215.68 0.02 21.5 0.35 0.38 1 0.00 45.0 2.06 0.00 4.85 0.89
35 216.04 0.02 21.4 0.35 0.38 1 0.00 45.0 1.72 0.00 4.05 0.89
36 216.39 0.01 21.3 0.35 0.38 1 0.00 45.0 1.38 0.00 3.26 0.89
37 216.74 0.01 21.3 0.35 0.38 1 0.00 45.0 1.02 0.00 2.41 0.89
38 217.09 0.01 21.2 0.35 0.38 1 0.00 45.0 0.64 0.00 1.52 0.89
39 217.45 0.00 21.1 0.35 0.38 1 0.00 45.0 0.21 0.00 0.49 0.89
-------- ------- ----------
X-S Area: 0.95 Path Length: 14.38 X-S Weight: 97.46
————————————————————————————————————————————————————————————————————————————————————————————————
2. Analysis 2 - Cross Section 1 - Mining Slope with Rapid Drawdown
Material Properties (2 materials)
-------------------
Material: 1 (Mohr-Coulomb Isotropic) - Sand and gravel, mixed grain size
Cohesion Phi UnitWeight Ru
0.00 45.0 110.00 Auto
Material: 2 (Mohr-Coulomb Isotropic) - Loose sand, mixed grain size
Cohesion Phi UnitWeight Ru
0.00 34.0 99.00 Auto
Water Properties
----------------
Unit weight of water: 62.400 Unit weight of water/medium above ground: 62.400
Material Profiles (2 profiles)
-----------------
Profile: 1 (3 points) Material beneath: 2 - Loose sand, mixed grain size
0.00 5389.52
204.04 5391.91
348.51 5390.21
Profile: 2 (3 points) Material beneath: 1 - Sand and gravel, mixed grain size
0.04 5386.02
204.04 5388.41
348.47 5386.71
Slope Surface (4 points)
-------------
0.00 5389.52
204.04 5391.91
256.59 5370.00 348.51 5370.00
Piezometric Surfaces (1 surface)
--------------------
Surface within profile: 1 (4 points) - Loose sand, mixed grain size
0.20 5385.10
212.60 5387.70
256.00 5369.20
348.40 5369.70
Failure Surface
---------------
Initial circular surface for critical search defined by: XL,XR,R
Intersects: XL: 176.40 YL: 5391.59 XR: 255.30 YR: 5370.54
Centre: XC: 279.42 YC: 5619.37 Radius: R: 250.00
Variable Restraints
-------------------
Parameter descriptor: XL XR R
Range of variation: 75.00 75.00 25.00
Trial positions within range: 25 25 25
- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -
RESULTS: Analysis 2 - Cross Section 1 - Mining Slope with Rapid Drawdown
Bishop Simplified Method of Analysis - Circular Failure Surface
---------------------------------------------------------------
Critical Failure Surface Search using Multiple Circle Generation Techniques
Initial failure surface approximation - Factor of Safety: 3.645
Analysis Summary
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
There were: 10633 successful analyses from a total of 15625 trial failure surfaces
4992 analyses terminated due to unacceptable geometry
Critical (minimum) Factor of Safety: 1.91
——————————————————————————————————————————
Results Summary - Lowest 99 Factor of Safety circles
----------------------------------------------------
Circle X-Left Y-Left X-Right Y-Right X-Centre Y-Centre Radius FoS
1 204.52 5391.71 217.80 5386.17 311.34 5629.21 260.42 1.909 <-- Critical Surface
2 204.52 5391.71 217.80 5386.17 310.94 5628.25 259.38 1.909
3 204.52 5391.71 217.80 5386.17 311.75 5630.17 261.46 1.909
4 204.52 5391.71 217.80 5386.17 312.15 5631.13 262.50 1.909
5 204.52 5391.71 217.80 5386.17 310.54 5627.28 258.33 1.910
6 204.52 5391.71 217.80 5386.17 308.54 5622.48 253.12 1.910
7 204.52 5391.71 217.80 5386.17 309.34 5624.40 255.21 1.910
8 204.52 5391.71 217.80 5386.17 309.74 5625.36 256.25 1.910
9 204.52 5391.71 217.80 5386.17 308.94 5623.44 254.17 1.910
10 204.52 5391.71 217.80 5386.17 310.14 5626.32 257.29 1.910
11 204.52 5391.71 217.80 5386.17 306.93 5618.63 248.96 1.910
12 204.52 5391.71 217.80 5386.17 308.14 5621.51 252.08 1.910
13 204.52 5391.71 217.80 5386.17 307.33 5619.59 250.00 1.911
14 204.52 5391.71 217.80 5386.17 305.73 5615.74 245.83 1.911
15 204.52 5391.71 217.80 5386.17 307.74 5620.55 251.04 1.911
16 204.52 5391.71 217.80 5386.17 304.93 5613.82 243.75 1.911
17 204.52 5391.71 217.80 5386.17 306.53 5617.67 247.92 1.911
18 204.52 5391.71 217.80 5386.17 306.13 5616.70 246.88 1.911
19 204.52 5391.71 217.80 5386.17 305.33 5614.78 244.79 1.911
20 204.52 5391.71 217.80 5386.17 304.13 5611.90 241.67 1.911
21 204.52 5391.71 217.80 5386.17 303.72 5610.93 240.62 1.911
22 204.52 5391.71 217.80 5386.17 304.53 5612.86 242.71 1.911
23 204.52 5391.71 217.80 5386.17 303.32 5609.97 239.58 1.912
24 204.52 5391.71 217.80 5386.17 302.92 5609.01 238.54 1.912
25 204.52 5391.71 217.80 5386.17 302.52 5608.05 237.50 1.912
26 207.65 5390.40 217.80 5386.17 313.32 5629.56 261.46 2.042
27 207.65 5390.40 217.80 5386.17 312.92 5628.60 260.42 2.042
28 207.65 5390.40 217.80 5386.17 313.72 5630.52 262.50 2.043
29 207.65 5390.40 217.80 5386.17 309.71 5620.90 252.08 2.043
30 207.65 5390.40 217.80 5386.17 310.11 5621.86 253.12 2.043
31 207.65 5390.40 217.80 5386.17 310.51 5622.83 254.17 2.043
32 207.65 5390.40 217.80 5386.17 310.91 5623.79 255.21 2.044
33 207.65 5390.40 217.80 5386.17 312.12 5626.67 258.33 2.044
34 207.65 5390.40 217.80 5386.17 311.72 5625.71 257.29 2.044
35 207.65 5390.40 217.80 5386.17 308.51 5618.02 248.96 2.044
36 207.65 5390.40 217.80 5386.17 311.31 5624.75 256.25 2.044
37 207.65 5390.40 217.80 5386.17 312.52 5627.63 259.38 2.044
38 207.65 5390.40 217.80 5386.17 308.91 5618.98 250.00 2.044
39 207.65 5390.40 217.80 5386.17 307.31 5615.13 245.83 2.044
40 207.65 5390.40 217.80 5386.17 309.31 5619.94 251.04 2.044
41 207.65 5390.40 217.80 5386.17 306.10 5612.25 242.71 2.044
42 207.65 5390.40 217.80 5386.17 308.11 5617.06 247.92 2.044
43 207.65 5390.40 217.80 5386.17 305.70 5611.29 241.67 2.044
44 207.65 5390.40 217.80 5386.17 306.90 5614.17 244.79 2.044
45 207.65 5390.40 217.80 5386.17 304.90 5609.36 239.58 2.044
46 207.65 5390.40 217.80 5386.17 306.50 5613.21 243.75 2.044
47 207.65 5390.40 217.80 5386.17 307.71 5616.09 246.88 2.044
48 207.65 5390.40 217.80 5386.17 305.30 5610.32 240.62 2.045
49 207.65 5390.40 217.80 5386.17 304.50 5608.40 238.54 2.045
50 207.65 5390.40 217.80 5386.17 304.10 5607.44 237.50 2.046
51 204.52 5391.71 220.93 5384.87 313.69 5630.43 262.50 2.056
52 204.52 5391.71 220.93 5384.87 312.88 5628.51 260.42 2.057
53 204.52 5391.71 220.93 5384.87 311.68 5625.62 257.29 2.057
54 204.52 5391.71 220.93 5384.87 310.08 5621.78 253.12 2.057
55 204.52 5391.71 220.93 5384.87 312.08 5626.59 258.33 2.057
56 204.52 5391.71 220.93 5384.87 312.48 5627.55 259.38 2.057
57 204.52 5391.71 220.93 5384.87 310.88 5623.70 255.21 2.057
58 204.52 5391.71 220.93 5384.87 310.48 5622.74 254.17 2.057
59 204.52 5391.71 220.93 5384.87 313.28 5629.47 261.46 2.057
60 204.52 5391.71 220.93 5384.87 308.47 5617.93 248.96 2.057
61 204.52 5391.71 220.93 5384.87 309.67 5620.81 252.08 2.057
62 204.52 5391.71 220.93 5384.87 308.87 5618.89 250.00 2.057
63 204.52 5391.71 220.93 5384.87 308.07 5616.97 247.92 2.057
64 204.52 5391.71 220.93 5384.87 311.28 5624.66 256.25 2.057
65 204.52 5391.71 220.93 5384.87 306.47 5613.12 243.75 2.057
66 204.52 5391.71 220.93 5384.87 309.27 5619.85 251.04 2.057
67 204.52 5391.71 220.93 5384.87 306.87 5614.08 244.79 2.057
68 204.52 5391.71 220.93 5384.87 304.46 5608.31 238.54 2.057
69 204.52 5391.71 220.93 5384.87 307.67 5616.00 246.88 2.057
70 204.52 5391.71 220.93 5384.87 307.27 5615.04 245.83 2.057
71 204.52 5391.71 220.93 5384.87 306.06 5612.16 242.71 2.057
72 204.52 5391.71 220.93 5384.87 305.26 5610.23 240.62 2.057
73 204.52 5391.71 220.93 5384.87 304.06 5607.34 237.50 2.058
74 204.52 5391.71 220.93 5384.87 305.66 5611.19 241.67 2.058
75 204.52 5391.71 220.93 5384.87 304.86 5609.27 239.58 2.058
76 201.40 5391.88 217.80 5386.17 295.48 5635.83 261.46 2.116
77 201.40 5391.88 217.80 5386.17 295.82 5636.81 262.50 2.116
78 201.40 5391.88 217.80 5386.17 295.13 5634.84 260.42 2.116
79 201.40 5391.88 217.80 5386.17 294.79 5633.86 259.38 2.116
80 201.40 5391.88 217.80 5386.17 294.45 5632.87 258.33 2.117
81 201.40 5391.88 217.80 5386.17 294.11 5631.89 257.29 2.117
82 201.40 5391.88 217.80 5386.17 293.76 5630.90 256.25 2.117
83 201.40 5391.88 217.80 5386.17 293.42 5629.92 255.21 2.117
84 201.40 5391.88 217.80 5386.17 293.08 5628.94 254.17 2.117
85 201.40 5391.88 217.80 5386.17 292.74 5627.95 253.12 2.117
86 201.40 5391.88 217.80 5386.17 292.39 5626.97 252.08 2.117
87 201.40 5391.88 217.80 5386.17 292.05 5625.98 251.04 2.117
88 201.40 5391.88 217.80 5386.17 291.37 5624.01 248.96 2.117
89 201.40 5391.88 217.80 5386.17 291.71 5625.00 250.00 2.117
90 201.40 5391.88 217.80 5386.17 290.34 5621.06 245.83 2.117
91 201.40 5391.88 217.80 5386.17 291.02 5623.03 247.92 2.117
92 201.40 5391.88 217.80 5386.17 290.68 5622.04 246.88 2.117
93 201.40 5391.88 217.80 5386.17 290.00 5620.08 244.79 2.118
94 201.40 5391.88 217.80 5386.17 289.65 5619.09 243.75 2.118
95 201.40 5391.88 217.80 5386.17 289.31 5618.11 242.71 2.118
96 201.40 5391.88 217.80 5386.17 288.97 5617.12 241.67 2.118
97 201.40 5391.88 217.80 5386.17 288.63 5616.14 240.62 2.118
98 201.40 5391.88 217.80 5386.17 288.28 5615.15 239.58 2.118
99 201.40 5391.88 217.80 5386.17 287.94 5614.17 238.54 2.118
Critical Failure Surface (circle 1)
------------------------
Intersects: XL: 204.52 YL: 5391.71 XR: 217.80 YR: 5386.17
Centre: XC: 311.34 YC: 5629.21 Radius: R: 260.42
Generated failure surface: (20 points)
204.52 5391.71 205.22 5391.40 205.91 5391.09 206.60 5390.79 207.29 5390.48
207.99 5390.18 208.68 5389.88 209.38 5389.58 210.08 5389.29 210.78 5388.99
211.47 5388.70 212.17 5388.41 212.87 5388.13 213.58 5387.84 214.28 5387.56
214.98 5387.28 215.68 5387.00 216.39 5386.72 217.09 5386.45 217.80 5386.17
Slice Geometry and Properties - Critical Failure Surface (circle 1, 39 slices)
--------------------------------------------------------
Slice X-S ------------------- Base --------------------- PoreWater Normal Test
X-Left Area Angle Width Length Matl Cohesion Phi Weight Force Stress Factor
1 204.52 0.00 24.1 0.35 0.38 2 0.00 34.0 0.17 0.00 0.42 0.95
2 204.87 0.01 24.1 0.35 0.38 2 0.00 34.0 0.55 0.00 1.38 0.95
3 205.22 0.01 24.0 0.35 0.38 2 0.00 34.0 0.90 0.00 2.26 0.95
4 205.56 0.01 24.0 0.35 0.38 2 0.00 34.0 1.22 0.00 3.05 0.95
5 205.91 0.02 23.7 0.35 0.38 2 0.00 34.0 1.52 0.00 3.81 0.95
6 206.25 0.02 23.8 0.35 0.38 2 0.00 34.0 1.81 0.00 4.52 0.95
7 206.60 0.02 23.7 0.35 0.38 2 0.00 34.0 2.08 0.00 5.19 0.95
8 206.95 0.02 23.7 0.35 0.38 2 0.00 34.0 2.33 0.00 5.82 0.95
9 207.29 0.03 23.5 0.35 0.38 2 0.00 34.0 2.55 0.00 6.37 0.95
10 207.64 0.03 23.4 0.35 0.38 2 0.00 34.0 2.77 0.00 6.92 0.95
11 207.99 0.03 23.3 0.35 0.38 2 0.00 34.0 2.94 0.00 7.34 0.95
12 208.34 0.03 23.3 0.35 0.38 2 0.00 34.0 3.13 0.00 7.80 0.95
13 208.68 0.03 23.1 0.35 0.38 2 0.00 34.0 3.26 0.00 8.15 0.94
14 209.03 0.03 23.2 0.35 0.38 2 0.00 34.0 3.40 0.00 8.48 0.94
15 209.38 0.04 23.0 0.35 0.38 2 0.00 34.0 3.49 0.00 8.70 0.94
16 209.73 0.04 22.9 0.35 0.38 2 0.00 34.0 3.59 0.00 8.96 0.94
17 210.08 0.04 22.8 0.35 0.38 2 0.00 34.0 3.64 0.00 9.09 0.94
18 210.43 0.04 22.8 0.35 0.38 2 0.00 34.0 3.69 0.00 9.21 0.94
19 210.78 0.04 22.6 0.35 0.38 2 0.00 34.0 3.72 0.00 9.27 0.94
20 211.12 0.04 22.6 0.35 0.38 2 0.00 34.0 3.70 0.00 9.23 0.94
21 211.47 0.04 22.5 0.35 0.38 2 0.00 34.0 3.69 0.00 9.19 0.94
22 211.82 0.04 22.4 0.35 0.38 2 0.00 34.0 3.65 0.00 9.11 0.94
23 212.17 0.03 22.3 0.25 0.27 2 0.00 34.0 2.58 0.00 8.99 0.94
24 212.42 0.03 22.3 0.25 0.28 1 0.00 45.0 2.71 0.00 8.77 0.89
25 212.68 0.02 22.3 0.20 0.21 1 0.00 45.0 2.16 0.00 9.11 0.89
26 212.87 0.03 22.1 0.35 0.38 1 0.00 45.0 3.79 0.00 8.90 0.89
27 213.22 0.03 22.1 0.35 0.38 1 0.00 45.0 3.65 0.00 8.59 0.89
28 213.58 0.03 22.0 0.35 0.38 1 0.00 45.0 3.49 0.00 8.20 0.89
29 213.93 0.03 22.0 0.35 0.38 1 0.00 45.0 3.30 0.00 7.76 0.89
30 214.28 0.03 21.8 0.35 0.38 1 0.00 45.0 3.10 0.00 7.28 0.89
31 214.63 0.03 21.8 0.35 0.38 1 0.00 45.0 2.87 0.00 6.75 0.89
32 214.98 0.02 21.6 0.35 0.38 1 0.00 45.0 2.63 0.00 6.18 0.89
33 215.33 0.02 21.6 0.35 0.38 1 0.00 45.0 2.34 0.00 5.51 0.89
34 215.68 0.02 21.5 0.35 0.38 1 0.00 45.0 2.06 0.00 4.85 0.89
35 216.04 0.02 21.4 0.35 0.38 1 0.00 45.0 1.72 0.00 4.05 0.89
36 216.39 0.01 21.3 0.35 0.38 1 0.00 45.0 1.38 0.00 3.26 0.89
37 216.74 0.01 21.3 0.35 0.38 1 0.00 45.0 1.02 0.00 2.41 0.89
38 217.09 0.01 21.2 0.35 0.38 1 0.00 45.0 0.64 0.00 1.52 0.89
39 217.45 0.00 21.1 0.35 0.38 1 0.00 45.0 0.21 0.00 0.49 0.89
-------- ------- ----------
X-S Area: 0.95 Path Length: 14.38 X-S Weight: 97.46
————————————————————————————————————————————————————————————————————————————————————————————————
3. Analysis 3 - Cross Section 1 - Reclaimed Slope with Groundwater
Material Properties (2 materials)
-------------------
Material: 1 (Mohr-Coulomb Isotropic) - Sand and gravel, mixed grain size
Cohesion Phi UnitWeight Ru
0.00 45.0 110.00 Auto
Material: 2 (Mohr-Coulomb Isotropic) - Loose sand, mixed grain size
Cohesion Phi UnitWeight Ru
0.00 34.0 99.00 Auto
Water Properties
----------------
Unit weight of water: 62.400 Unit weight of water/medium above ground: 62.400
Material Profiles (2 profiles)
-----------------
Profile: 1 (3 points) Material beneath: 2 - Loose sand, mixed grain size
0.00 5389.52
204.04 5391.91
348.51 5390.21
Profile: 2 (3 points) Material beneath: 1 - Sand and gravel, mixed grain size
0.04 5386.02
204.04 5388.41
348.47 5386.71
Slope Surface (6 points)
-------------
0.00 5389.52
204.04 5391.91
233.84 5386.99
254.98 5379.99
274.04 5370.00
348.51 5370.00
Phreatic Surface (2 points)
----------------
0.00 5385.00
400.00 5385.00
Failure Surface
---------------
Initial circular surface for critical search defined by: XL,XR,R
Intersects: XL: 189.90 YL: 5391.74 XR: 273.40 YR: 5370.34
Centre: XC: 292.81 YC: 5619.58 Radius: R: 250.00
Variable Restraints
-------------------
Parameter descriptor: XL XR R
Range of variation: 54.50 100.00 25.00
Trial positions within range: 25 25 25
- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -
- -- -- -- -- -- -- -- -- -
RESULTS: Analysis 3 - Cross Section 1 - Reclaimed Slope with Groundwater
Bishop Simplified Method of Analysis - Circular Failure Surface
---------------------------------------------------------------
Critical Failure Surface Search using Multiple Circle Generation Techniques
Initial failure surface approximation - Factor of Safety: 3.613
Analysis Summary
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
There were: 11084 successful analyses from a total of 15625 trial failure surfaces
4541 analyses terminated due to unacceptable geometry
Critical (minimum) Factor of Safety: 2.78
——————————————————————————————————————————
Results Summary - Lowest 99 Factor of Safety circles
----------------------------------------------------
Circle X-Left Y-Left X-Right Y-Right X-Centre Y-Centre Radius FoS
1 217.15 5389.75 273.40 5370.34 322.14 5602.78 237.50 2.779 <-- Critical Surface
2 217.15 5389.75 273.40 5370.34 322.48 5603.77 238.54 2.780
3 217.15 5389.75 273.40 5370.34 322.82 5604.77 239.58 2.780
4 217.15 5389.75 273.40 5370.34 323.16 5605.76 240.62 2.780
5 217.15 5389.75 273.40 5370.34 323.51 5606.75 241.67 2.780
6 217.15 5389.75 273.40 5370.34 323.85 5607.74 242.71 2.781
7 217.15 5389.75 273.40 5370.34 324.19 5608.73 243.75 2.781
8 217.15 5389.75 273.40 5370.34 324.53 5609.73 244.79 2.781
9 217.15 5389.75 273.40 5370.34 324.88 5610.72 245.83 2.781
10 217.15 5389.75 273.40 5370.34 325.22 5611.71 246.88 2.782
11 217.15 5389.75 273.40 5370.34 325.56 5612.70 247.92 2.782
12 217.15 5389.75 273.40 5370.34 325.90 5613.69 248.96 2.782
13 217.15 5389.75 273.40 5370.34 326.24 5614.69 250.00 2.782
14 217.15 5389.75 273.40 5370.34 326.59 5615.68 251.04 2.783
15 217.15 5389.75 273.40 5370.34 326.93 5616.67 252.08 2.783
16 217.15 5389.75 273.40 5370.34 327.27 5617.66 253.12 2.783
17 217.15 5389.75 273.40 5370.34 327.61 5618.65 254.17 2.783
18 217.15 5389.75 273.40 5370.34 327.96 5619.64 255.21 2.784
19 217.15 5389.75 273.40 5370.34 328.30 5620.64 256.25 2.784
20 217.15 5389.75 273.40 5370.34 328.64 5621.63 257.29 2.784
21 217.15 5389.75 273.40 5370.34 328.98 5622.62 258.33 2.784
22 217.15 5389.75 273.40 5370.34 329.32 5623.61 259.38 2.784
23 217.15 5389.75 273.40 5370.34 329.67 5624.60 260.42 2.785
24 217.15 5389.75 273.40 5370.34 330.01 5625.59 261.46 2.785
25 217.15 5389.75 273.40 5370.34 330.35 5626.58 262.50 2.785
26 214.88 5390.12 273.40 5370.34 319.56 5603.31 237.50 2.830
27 214.88 5390.12 273.40 5370.34 319.90 5604.30 238.54 2.831
28 214.88 5390.12 273.40 5370.34 320.23 5605.30 239.58 2.831
29 214.88 5390.12 273.40 5370.34 320.57 5606.29 240.62 2.831
30 214.88 5390.12 273.40 5370.34 320.91 5607.29 241.67 2.831
31 214.88 5390.12 273.40 5370.34 321.24 5608.28 242.71 2.832
32 214.88 5390.12 273.40 5370.34 321.58 5609.28 243.75 2.832
33 214.88 5390.12 273.40 5370.34 321.91 5610.27 244.79 2.832
34 214.88 5390.12 273.40 5370.34 322.25 5611.27 245.83 2.832
35 214.88 5390.12 273.40 5370.34 322.59 5612.26 246.88 2.833
36 214.88 5390.12 273.40 5370.34 322.92 5613.26 247.92 2.833
37 214.88 5390.12 273.40 5370.34 323.26 5614.25 248.96 2.833
38 214.88 5390.12 273.40 5370.34 323.60 5615.24 250.00 2.833
39 214.88 5390.12 273.40 5370.34 323.93 5616.24 251.04 2.834
40 214.88 5390.12 273.40 5370.34 324.27 5617.23 252.08 2.834
41 214.88 5390.12 273.40 5370.34 324.60 5618.23 253.12 2.834
42 214.88 5390.12 273.40 5370.34 324.94 5619.22 254.17 2.834
43 214.88 5390.12 273.40 5370.34 325.28 5620.22 255.21 2.835
44 214.88 5390.12 273.40 5370.34 325.61 5621.21 256.25 2.835
45 214.88 5390.12 273.40 5370.34 325.95 5622.20 257.29 2.835
46 214.88 5390.12 273.40 5370.34 326.28 5623.20 258.33 2.835
47 214.88 5390.12 273.40 5370.34 326.62 5624.19 259.38 2.836
48 214.88 5390.12 273.40 5370.34 326.96 5625.19 260.42 2.836
49 214.88 5390.12 273.40 5370.34 327.29 5626.18 261.46 2.836
50 214.88 5390.12 273.40 5370.34 327.63 5627.17 262.50 2.836
51 212.61 5390.50 273.40 5370.34 317.08 5603.78 237.50 2.880
52 212.61 5390.50 273.40 5370.34 317.41 5604.78 238.54 2.880
53 212.61 5390.50 273.40 5370.34 317.74 5605.78 239.58 2.880
54 212.61 5390.50 273.40 5370.34 318.07 5606.78 240.62 2.880
55 212.61 5390.50 273.40 5370.34 318.40 5607.77 241.67 2.881
56 212.61 5390.50 273.40 5370.34 318.73 5608.77 242.71 2.881
57 212.61 5390.50 273.40 5370.34 319.06 5609.77 243.75 2.881
58 212.61 5390.50 273.40 5370.34 319.39 5610.77 244.79 2.881
59 212.61 5390.50 273.40 5370.34 319.73 5611.76 245.83 2.882
60 212.61 5390.50 273.40 5370.34 320.06 5612.76 246.88 2.882
61 212.61 5390.50 273.40 5370.34 320.39 5613.76 247.92 2.882
62 212.61 5390.50 273.40 5370.34 320.72 5614.76 248.96 2.882
63 212.61 5390.50 273.40 5370.34 321.05 5615.75 250.00 2.883
64 212.61 5390.50 273.40 5370.34 321.38 5616.75 251.04 2.883
65 212.61 5390.50 273.40 5370.34 321.71 5617.75 252.08 2.883
66 212.61 5390.50 273.40 5370.34 322.04 5618.74 253.12 2.883
67 212.61 5390.50 273.40 5370.34 322.37 5619.74 254.17 2.884
68 212.61 5390.50 273.40 5370.34 322.70 5620.74 255.21 2.884
69 212.61 5390.50 273.40 5370.34 323.03 5621.73 256.25 2.884
70 212.61 5390.50 273.40 5370.34 323.36 5622.73 257.29 2.884
71 212.61 5390.50 273.40 5370.34 323.69 5623.73 258.33 2.885
72 212.61 5390.50 273.40 5370.34 324.02 5624.72 259.38 2.885
73 212.61 5390.50 273.40 5370.34 324.35 5625.72 260.42 2.885
74 212.61 5390.50 273.40 5370.34 324.68 5626.71 261.46 2.885
75 212.61 5390.50 273.40 5370.34 325.01 5627.71 262.50 2.886
76 217.15 5389.75 269.23 5372.52 317.27 5605.11 237.50 2.900
77 217.15 5389.75 269.23 5372.52 317.60 5606.11 238.54 2.900
78 217.15 5389.75 269.23 5372.52 317.93 5607.10 239.58 2.900
79 217.15 5389.75 269.23 5372.52 318.26 5608.10 240.62 2.901
80 217.15 5389.75 269.23 5372.52 318.59 5609.09 241.67 2.901
81 217.15 5389.75 269.23 5372.52 318.92 5610.09 242.71 2.901
82 217.15 5389.75 269.23 5372.52 319.25 5611.08 243.75 2.901
83 217.15 5389.75 269.23 5372.52 319.57 5612.08 244.79 2.902
84 217.15 5389.75 269.23 5372.52 319.90 5613.07 245.83 2.902
85 217.15 5389.75 269.23 5372.52 320.23 5614.07 246.88 2.902
86 217.15 5389.75 269.23 5372.52 320.56 5615.06 247.92 2.903
87 217.15 5389.75 269.23 5372.52 320.89 5616.06 248.96 2.903
88 217.15 5389.75 269.23 5372.52 321.22 5617.05 250.00 2.903
89 217.15 5389.75 269.23 5372.52 321.55 5618.05 251.04 2.903
90 217.15 5389.75 269.23 5372.52 321.88 5619.04 252.08 2.904
91 217.15 5389.75 269.23 5372.52 322.21 5620.04 253.12 2.904
92 217.15 5389.75 269.23 5372.52 322.54 5621.03 254.17 2.904
93 217.15 5389.75 269.23 5372.52 322.87 5622.03 255.21 2.904
94 217.15 5389.75 269.23 5372.52 323.19 5623.02 256.25 2.905
95 217.15 5389.75 269.23 5372.52 323.52 5624.02 257.29 2.905
96 217.15 5389.75 269.23 5372.52 323.85 5625.01 258.33 2.905
97 217.15 5389.75 269.23 5372.52 324.18 5626.01 259.38 2.906
98 217.15 5389.75 269.23 5372.52 324.51 5627.00 260.42 2.906
99 217.15 5389.75 269.23 5372.52 324.84 5628.00 261.46 2.906
Critical Failure Surface (circle 1)
------------------------
Intersects: XL: 217.15 YL: 5389.75 XR: 273.40 YR: 5370.34
Centre: XC: 322.14 YC: 5602.78 Radius: R: 237.50
Generated failure surface: (20 points)
217.15 5389.75 219.98 5388.38 222.82 5387.04 225.68 5385.75 228.56 5384.49
231.45 5383.28 234.36 5382.10 237.29 5380.95 240.23 5379.85 243.18 5378.79
246.15 5377.76 249.13 5376.78 252.13 5375.83 255.13 5374.93 258.15 5374.06
261.18 5373.24 264.22 5372.45 267.27 5371.71 270.33 5371.00 273.40 5370.34
Slice Geometry and Properties - Critical Failure Surface (circle 1, 42 slices)
--------------------------------------------------------
Slice X-S ------------------- Base --------------------- PoreWater Normal Test
X-Left Area Angle Width Length Matl Cohesion Phi Weight Force Stress Factor
1 217.15 0.32 25.9 1.41 1.57 2 0.00 34.0 31.55 0.00 19.98 0.99
2 218.56 0.96 25.9 1.41 1.57 2 0.00 34.0 94.80 0.00 60.04 0.99
3 219.98 0.32 25.1 0.34 0.37 2 0.00 34.0 31.74 0.00 84.83 0.99
4 220.31 1.50 25.1 1.25 1.38 1 0.00 45.0 152.26 0.00 103.92 0.95
5 221.57 1.97 25.1 1.25 1.38 1 0.00 45.0 207.37 0.00 141.55 0.94
6 222.82 2.82 24.3 1.43 1.57 1 0.00 45.0 302.06 0.00 181.61 0.94
7 224.25 3.41 24.4 1.43 1.57 1 0.00 45.0 370.19 0.00 222.55 0.94
8 225.68 3.26 23.6 1.19 1.29 1 0.00 45.0 357.65 0.00 260.44 0.94
9 226.87 1.58 23.6 0.53 0.58 1 0.00 45.0 174.21 0.00 283.47 0.94
10 227.40 3.72 23.6 1.16 1.27 1 0.00 45.0 409.66 19.97 307.40 0.94
11 228.56 5.14 22.8 1.45 1.57 1 0.00 45.0 565.67 79.45 346.16 0.94
12 230.01 5.68 22.8 1.45 1.57 1 0.00 45.0 624.51 139.05 386.47 0.94
13 231.45 5.08 22.1 1.19 1.29 1 0.00 45.0 558.47 158.08 423.81 0.94
14 232.65 5.42 22.1 1.19 1.29 1 0.00 45.0 596.11 196.96 455.21 0.94
15 233.84 2.46 22.1 0.52 0.56 1 0.00 45.0 270.16 98.42 473.59 0.94
16 234.36 6.97 21.3 1.46 1.57 1 0.00 45.0 766.60 312.45 484.12 0.94
17 235.82 7.10 21.3 1.46 1.57 1 0.00 45.0 780.50 368.41 496.81 0.94
18 237.29 6.31 20.6 1.28 1.37 1 0.00 45.0 693.84 365.98 508.89 0.94
19 238.57 6.38 20.5 1.28 1.37 1 0.00 45.0 701.77 406.97 517.92 0.94
20 239.85 1.89 20.6 0.38 0.40 1 0.00 45.0 208.09 127.65 527.06 0.94
21 240.23 7.45 19.8 1.48 1.57 1 0.00 45.0 819.54 530.32 550.32 0.94
22 241.71 7.51 19.8 1.48 1.57 1 0.00 45.0 826.52 582.46 585.34 0.94
23 243.18 7.60 19.0 1.48 1.57 1 0.00 45.0 835.52 633.58 620.22 0.94
24 244.67 7.63 19.0 1.48 1.57 1 0.00 45.0 839.02 683.81 653.13 0.94
25 246.15 7.68 18.3 1.49 1.57 1 0.00 45.0 844.27 732.91 685.89 0.94
26 247.64 7.67 18.3 1.49 1.57 1 0.00 45.0 844.11 781.25 716.57 0.94
27 249.13 7.69 17.5 1.50 1.57 1 0.00 45.0 845.71 828.47 747.19 0.94
28 250.63 7.65 17.5 1.50 1.57 1 0.00 45.0 841.93 874.77 775.71 0.94
29 252.13 7.25 16.8 1.43 1.49 1 0.00 45.0 797.12 872.17 803.46 0.94
30 253.55 7.19 16.8 1.43 1.49 1 0.00 45.0 790.46 912.21 828.43 0.94
31 254.98 7.66 16.1 1.59 1.65 1 0.00 45.0 842.43 1056.03 848.19 0.94
32 256.57 7.06 16.0 1.59 1.65 1 0.00 45.0 776.84 1102.52 860.45 0.94
33 258.15 6.17 15.3 1.51 1.57 1 0.00 45.0 679.01 1091.80 872.04 0.94
34 259.67 5.60 15.2 1.51 1.57 1 0.00 45.0 615.46 1132.11 881.27 0.94
35 261.18 5.02 14.5 1.52 1.57 1 0.00 45.0 551.99 1171.68 890.04 0.94
36 262.70 4.41 14.5 1.52 1.57 1 0.00 45.0 484.55 1210.24 897.03 0.94
37 264.22 3.79 13.7 1.53 1.57 1 0.00 45.0 416.54 1247.67 903.35 0.95
38 265.75 3.14 13.7 1.53 1.57 1 0.00 45.0 344.95 1284.27 907.92 0.95
39 267.27 2.48 13.0 1.53 1.57 1 0.00 45.0 272.33 1319.80 911.73 0.95
40 268.80 1.79 13.0 1.53 1.57 1 0.00 45.0 196.65 1354.33 913.96 0.95
41 270.33 1.09 12.2 1.53 1.57 1 0.00 45.0 119.50 1387.85 915.22 0.95
42 271.87 0.36 12.2 1.53 1.57 1 0.00 45.0 39.89 1420.31 915.15 0.95
-------- ------- ----------
X-S Area: 196.14 Path Length: 59.66 X-S Weight: 21521.56
————————————————————————————————————————————————————————————————————————————————————————————————