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Erosion Control Report
For
Montava Subdivision Phase D
May 22, 2025
submitted to:
City of Fort Collins,
Colorado
Owner: Montava Partners LLC
225 N. 9th St. Suite 350
Boise, ID 83702-5735
Developer: Montava Development & Construction LLC
430. N. College Ave, Suite 410
Fort Collins, CO 80524
(512) 507-5570
Contractors: TBD
Design Engineer: TST Inc. Consulting Engineers
748 Whalers Way, Suite 200
Fort Collins, CO 80525
(970) 226-0557
748 Whalers Way
May 22, 2025
Mr. Andrew Crecca
City of Fort Collins
Environmental Regulatory Specialist
City Hall W 300 Laporte Ave
Fort Collins, CO 80521
Re: Montava Subdivision Phase D
Erosion Control Report
Project No. 1230.0009.00
Dear Mr. Crecca:
TST, Inc. Consulting Engineers (TST) is pleased to submit this Erosion Control
Report for the Montava Subdivision Phase D project to the City of Fort Collins
(City) for review and approval.
The purpose of this erosion control report is to outline the anticipated construction
practices and erosion pollution potential of the above-referenced proposed
Montava Subdivision Phase D project, as well as to provide a living document
and reference to coincide with any and all associated construction activities.
Please review the attached report and provide any questions or comments at your
earliest convenience. We appreciate the opportunity to be of continued service to
the city and look forward to receiving your comments and moving forward on this
important project.
Sincerely,
TST, INC. CONSULTING ENGINEERS
Brian R. Barker, E.I. Derek A. Patterson, P.E.
BRB DAP
I hereby attest that this erosion control report for the Montava Subdivision Phase D
was prepared by me or under my direct supervision, in accordance with the
provisions of the Fort Collins Stormwater Criteria Manual (FCSCM).
___________________
Derek A. Patterson
Registered Professional Engineer
State of Colorado No. 48898
748 Whalers Way
Suite 200
Fort Collins, CO 80525
970.226.0557 main
970.226.0204 fax
ideas@tstinc.com
www.tstinc.com
Table of Contents
Montava Subdivision Phase D: Erosion Control Report
Page i
1.0 - PROJECT DESCRIPTION AND NATURE OF CONSTRUCTION ......................... 1
1.1 Introduction ..................................................................................................... 1
1.2 Project Location and Description ................................................................... 1
1.3 Proposed Construction Activities .................................................................. 3
1.4 Existing Soil and Surface Conditions ............................................................ 4
1.5 Wetlands and Receiving Waters ..................................................................... 5
1.6 Erosion Control Administrator ....................................................................... 6
1.7 Potential Pollutants ......................................................................................... 6
2.0 - CONSTRUCTION CONTROL MEASURES ........................................................... 7
2.1 Controls Overview ........................................................................................... 7
2.2 Erosion and Sediment Controls ..................................................................... 7
2.3 Materials Management ...................................................................................13
2.4 Spill Management ...........................................................................................16
2.5 Non-Storm Water Components of Discharge ...............................................17
3.0 - MAINTENANCE AND INSPECTION REQUIREMENTS ...................................... 18
3.1 Inspection and Maintenance Overview .........................................................18
3.2 Minimum Monitoring Requirements ..............................................................18
3.3 Reporting Requirements / Inspection Reports .............................................19
3.4 Site Maps ........................................................................................................20
4.0 - FINAL VEGETATION AND STABILIZATION / CONCLUSION ........................... 20
5.0 - REFERENCES ...................................................................................................... 21
Montava Subdivision Phase D Erosion Control Report
Page ii
List of Figures
1.1 Vicinity Map ..................................................................................................................... 3
Technical Appendix
Appendix A – Final Subsurface Exploration Report
Appendix B – USDA Soil Survey Information
Appendix C – Urban Drainage and Flood Control District BMPs
Appendix D – Erosion Control Plan
Montava Subdivision Phase D Erosion Control Report
Page 1
1.0 - Project Description and Nature of Construction
1.1 Introduction
The following Erosion Control Report has been prepared for use during the construction of the
Montava Subdivision Phase D project. This plan describes recommended procedures and best
management practices, BMP’s, to assist the contractor in complying with the Colorado Water
Quality Control Act and the Federal Water Pollution Control Act. The intent of this plan is to
provide the contractor with a place to consolidate records, logs, permits, applications etc. as
well as guidance on water quality protection. It is critical that the contractor understands that
this plan is a living document that must be updated and maintained throughout the
construction process.
1.2 Project Location and Description
The Montava Subdivision Phase D project site is located in Section 32, Township 8 North,
Range 68 West of the 6th Principal Meridian, within the City of Fort Collins, Larimer County,
Colorado. The proposed site is bounded on the north by farmland, Future Montava Subdivision
phases, and Richards Lake Road. On the east by farmland, N. Giddings Road, and Future
Montava Subdivision phases. On the south by farmland and Mountain Vista Drive. On the west
by farmland, the Number 8 Outlet Ditch, and Future Montava Subdivision phases. The Montava
Subdivision Phase D project site contains a total of approximately 290 acres, with an estimated
158 acres to be disturbed, and consists of the Single-Family, Multi-Family, Mixed-Use, and
Open Space. Montava Subdivision Phase D is currently zoned as PUD. No offsite disturbance is
anticipated with this project.
The legal description of the project parcel is as follows:
A parcel of land, situate in the East Half (E1/2) of Section Thirty-two (32), Township
Eight North (T.8N.), Range Sixty-eight West (R.68W.) of the Sixth Principal Meridian (6th P.M.),
City of Fort Collins, County of Larimer, State of Colorado and being more particularly described
as follows:
COMMENCING at the Southeast corner of said Section 32 and assuming the South line of the
Southeast Quarter (SE1/4) as bearing North 89°57’58” West, a distance of 2639.84 feet,
monumented by a #6 rebar with 2.5” aluminum cap stamped LS 17497 at the East end and by a
3.25” aluminum cap stamped LS 20123 at the West end and with all other bearings contained
herein relative thereto;
THENCE North 45°15’52” West a distance of 71.08 feet to the North Right of Way (ROW) line of
Mountain Vista Drive, dedicated as Parcel 2 in the Deed recorded September 14, 1984, as Book
2289, Page 1283 of the Larimer County Clerk & Recorder (LCCR), to a line parallel with and
50.00 feet North of, as measured at a right angle, the South line of said SE1/4 and to the POINT
Montava Subdivision Phase D Erosion Control Report
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OF BEGINNING;
THENCE North 89°57’58” West, along said North line, a distance of 2514.83 feet to the East
line of that parcel described in the Warranty Deed dated June 18, 1904, as Book 187, Page 163
of the LCCR and to a line parallel with and 75.00 feet East of, as measured at a right angle, the
West line of said SE1/4;
THENCE North 00°33’32” West, along said East line, a distance of 2599.42 feet to the North
line of the SE1/4, the East line of that parcel described in the Warranty Deed dated June 17,
1904, as Book 187, Page 178 of the LCCR and to a line parallel with and 75.00 feet East of, as
measured at a right angle, the West line of the Northeast Quarter (NE1/4) of Section 32;
THENCE North 00°33’24” West, along said East line, a distance of 2590.24 feet to the South
ROW line of Richards Lake Road, dedicated as Parcel 1 in said Book 2289, Page 1283 and to a
line parallel with and 50.00 feet South of, as measured at a right angle, the North line NE1/4;
THENCE South 89°39’06” East, along said South line, a distance of 1608.80 feet to the West
line of that parcel described in the Warranty Deed dated May 15, 1886, as Book 44, Page 253
of the LCCR ;
THENCE South 45°07’27” East, along said West line, a distance of 1289.40 feet to the West
ROW line of North Giddings Road, dedicated as Parcel 1 of Book 2289, Page 1283 and to a line
parallel with and 50.00 feet West of, as measured at a right angle, the East line of the NE1/4;
THENCE South 00°35’37” East, along said West line, a distance of 1679.97 feet to the North
line of the SE1/4, the West ROW line of North Giddings Road, dedicated as Parcel 2 of Book
2289, Page 1283 and to a line parallel with and 50.00 feet West of, as measured at a right
angle, the East line of the SE1/4;
THENCE South 00°33’45” East a distance of 2591.61 feet to the POINT OF BEGINNING.
Said described parcel of land contains 12,621,362 Square Feet or 289.747 Acres, more or less
(±).
A vicinity map illustrating the project location is provided in Figure 1.1.
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Figure 1.1: Vicinity Map
1.3 Proposed Construction Activities
The contractor is the Erosion Control Administrator and will be responsible for implementing and
maintaining the erosion and sediment control, and pollution prevention measures described in
this document and the accompanying construction drawings and specifications. The contractor
may designate certain tasks as he sees fit, but the ultimate responsibility for ensuring the
implementation of these controls and their proper function remains with the contractor. The
order of major activities will be as follows:
1. Site Preparation: Confirm project disturbance limitations with those indicated on the
Erosion Control Plan and install initial sediment and erosion control and pollution
prevention BMP’s. All BMP’s must be shown on the Erosion Control Plan in the back
pocket of this report. Some BMP locations must be determined by the contractor and
marked on the plans in addition to the ones already shown.
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2. Schedule pre-construction inspection of BMPs with the City of Fort Collins to ensure
proper installation and functionality. Fill out an inspection report and file it in this report
notebook.
3. The general site construction process will start with mobilization and clearing/stripping.
4. Grading activities will then be completed, which require the installation of inlet protection,
surface roughing and erosion control blankets on slopes steeper than 3:1.
5. Utility installation will be the next phase where attention should be given to waste
management, outdoor storage areas, dewatering requirements, and rip-rap installation.
6. With the completion of utilities, the hardscape will start, which will require that attention
be given to items such as spill containment and concrete washout areas.
7. When the hardscape is completed, the buildings will start construction. Around each
individual building, site perimeter protection, such as staked straw wattles, shall be
installed for areas where sediment can run onto the hardscape.
8. As areas are completed the installation of permanent BMP’s, such as seeding, mulching,
spray-on matrix or rolled erosion control blankets on slopes shall be added.
9. Temporary seeding shall be added to areas that won’t be stabilized within 30 days.
10. Remove all temporary BMPs upon establishment of sufficient vegetative cover or other
permanent stabilization.
If at any time construction ceases for a period expected to exceed 30 days, such as the project
being split into multiple phases, temporary seeding of future phases shall be installed until
construction of each future phase has begun. In the event that the project is split into phases or
suspended, the permit may need to be inactivated or reassigned to the next administrator.
Permits required for this project include the CDPHE Construction Activity Permit, CDPHE
General Permit for Storm Water Discharge (COR400000), and CDPHE Colorado Discharge
Permit System (CDPS) Dewatering Permit.
1.4 Existing Soil and Surface Conditions
According to the final subsurface exploration completed by Earth Engineering Consultants, LLC,
dated April 22, 2024, groundwater depths range from 2 ½ to 11 feet below existing grades
throughout Montava Subdivision Phase D. This report is included in Appendix A. The site is
approximately 10% impervious area and has an estimated 70% vegetative cover.
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The types of soils found on the Montava Subdivision Phase D site consist of:
Aquepts, loamy (5).
Caruso clay loam (22) – 0 to 1 percent slopes.
Fort Collins loam (35) – 0 to 3 percent slopes.
Fort Collins loam (36) – 3 to 5 percent slopes.
Satanta loam (95) – 1 to 3 percent slopes.
Satanta Variant clay loam (98) – 0 to 3 percent slopes.
Stoneham loam (101) – 1 to 3 percent slopes.
The characteristics of the soil found on the project site include:
Slow to very slow infiltration rate when thoroughly wet.
Slow to very slow rate of water transmission.
Majority of the site has a wind erodibility rating of 5 and 6 (8 being the least susceptible)
These soils consist of the following hydrologic soil groups as defined in the United States
Department of Agriculture (USDA), Web Soil Survey:
Group B – 1.00%
Group C – 37.00%.
Group D – 62.00%.
These soil groups vary from a moderate to low wind erodibility and a majority of the site consists
of Group D soils meaning there will likely be slower infiltration when thoroughly wet (high runoff
potential). The USDA web soil survey report is included in Appendix B. Please refer to this
appendix for further description of soil characteristics.
1.5 Wetlands and Receiving Waters
The Montava Subdivision Phase D site is located in an undeveloped lot west of the Anheuser
Busch property. The current land is being used for agricultural purposes and undeveloped land.
The land currently consists of native grasses, bare ground, and crops. Runoff from the
undeveloped site has one flow path that ends up in the Larimer and Weld Canal that is located
south of the site. Phase D sheet flows southeast and is captured by a detention pond.
Stormwater will then be siphoned across the Larimer and Weld Canal, ultimately discharging
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into the Upper Cooper Slough. The existing site does not have any existing ponds or drainage
facilities. The site has an inadvertent detention area near Giddings Road and Mountain Vista
Drive.
There are no jurisdictional wetlands on site, however, there are wetlands that the city will require
to mitigate. A separate wetland mitigation document will be prepared.
1.6 Erosion Control Administrator
_________________________ shall be the designated Erosion Control Administrator for the
Project. It will be his or her responsibility to ensure the Erosion Control Report’s adequacy at all
times in order to effectively manage potential storm water pollutants throughout the course of
construction.
1.7 Potential Pollutants
Below is a list of potential pollution sources that can occur during the construction of site
improvements and potential remedies, or the appropriate section that should be referenced for
controlling these pollution sources:
All disturbed and stored soils – (Surface roughening, reseeding, mulching and silt
fence)
Vehicle tracking of sediments – (Vehicle tracking pads, street sweeping)
Management of contaminated soils – (See Section 2.3.2)
Loading and unloading operations – (See Section 2.2.3 - Stabilized Staging
Area)
Outdoor storage activities (building materials, fertilizers, chemicals, etc.) – (See
Section 2.3)
Vehicle and equipment maintenance and fueling - (See Section 2.3.2)
Significant dust or particulate generating processes – (See Section 2.2.3 – Wind
Erosion/Dust Control)
Routine maintenance activities involving fertilizers, pesticides, detergents, fuels,
solvents, oils, etc. (See Section 2.3.2)
On-site waste management practices (waste piles, liquid wastes, dumpsters,
etc.) – (See Section 2.3)
Concrete truck/equipment washing, including the concrete truck chute and
associated fixtures and equipment - (Use concrete wash-out)
Dedicated asphalt and concrete batch plants – (Not used on this project)
Non-industrial waste sources such as worker trash and portable toilets – (See
Section 2.3.2.- BMPs for San/Septic Waste)
Other areas or procedures where potential spills can occur (See Section 2.3)
Montava Subdivision Phase D Erosion Control Report
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2.0 - Construction Control Measures
2.1 Controls Overview
During construction, several control measures shall be implemented under the direction of the
contractor to prevent discharge of contaminated water. Specifications and details for specific
control measures are included in Appendix C of this report for use on the project. In addition to
those structural measures, other controls include non-structural practices, materials
management, spill prevention and management, and other miscellaneous controls as described
in the following sections.
2.2 Erosion and Sediment Controls
The objective of erosion control is to limit the amount of erosion occurring on disturbed areas
until stabilized. The objective of sediment control is to capture soil that has eroded before it
leaves the construction site. Despite the use of both erosion and sediment control measures, it
is recognized that some sediment could remain in runoff, especially during very large storm
events. The contractor shall utilize the best management practices (BMP’s) described in the
following sections to minimize the above potential to the maximum extent practicable.
During all phases of construction, the contractor should plan ahead of possible rainfall events
and work to limit erosion from occurring where potential exists. Where potential does exist
provide adequate conveyance, temporary or permanent, and direct runoff to BMP’s that trap
sediment. The erosion and sediment BMPs anticipated for use on the site include both
structural and non-structural practices.
2.2.1 Structural Practices
Structural BMPs are structures that limit erosion and sediment transport. Such
practices include check dams, silt fence, inlet and outlet protection, water quality ponds, and
grading techniques. The structural BMP’s that will be utilized on the subject site are described
in more detail as follows:
Sediment Control Logs (Wattles)
A linear roll made of natural materials such as straw or coconut fiber and staked
to the ground with a wooden stake.
To be used as a sediment barrier to intercept sheet flow from disturbed areas –
as perimeter control around stockpiles, inlet protection, check dams for small
drainage swales with low velocity.
To be installed along the contour.
Remove accumulated sediment once the depth is one half the height of the
sediment log and repair damage.
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Silt Fence
A temporary vertical barrier attached to and supported by posts entrenched in the
ground.
Utilized to intercept sediment from disturbed areas during construction.
For use in areas of shallow flow, not concentrated runoff.
Typically used at the toe of fills and in transitions between cuts and fills and along
streams.
Usually used as a perimeter control.
Installed prior to any land disturbing activity.
Shall be inspected periodically and after each rain or snowmelt event.
Not effective as a wind break.
Water Quality Ponds
A small temporary or permanent ponding area with a hard-lined spillway.
Utilized to detain sediment laden storm water and allow particles to settle out.
Should be installed prior to other land disturbing activities upstream.
Best used with other erosion prevention practices to limit sediment load in pond.
During construction, sediment shall be removed when the wet storage is reduced
by half.
Full capacity of ponds shall be re-established following stabilization.
Grading Techniques
Soil surface roughening, terracing and rounding at tops of cuts, transitions and
roadway ditches to facilitate vegetation and minimize erosion.
Disk surface to create ridges at least 6 inches deep following the land contour.
Used to temporarily stabilize disturbed areas immediately after grading.
After rainstorm events, rills that formed should be repaired immediately.
Inlet Protection
Permeable barriers installed around an inlet to filter runoff and remove sediment
prior to entering a storm drain inlet.
Constructed from rock socks, sediment control logs, silt fence, or other materials
approved by the local jurisdiction.
Not a stand-alone BMP and should be used in conjunction with other upgradient
BMPs.
When applying inlet protection in sump conditions, it is important that the inlet
continues to function during larger runoff events in order to prevent localized
flooding, public safety issues, and downstream erosion and damage from
bypassed flows.
Inspect frequently for tears, improper installation, displacement, and sediment
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accumulation.
Remove sediment accumulation from the area upstream of the inlet protection as
needed to maintain BMP effectiveness.
Propriety inlet protection devices should be inspected and maintained in
accordance with manufacturer specifications.
Inlet protection must be removed and properly disposed of when the drainage
area for the inlet has reached final stabilization.
Concrete Washout Area
Appropriate on all sites that will generate concrete wash water or liquid concrete
waste from onsite concrete mixing or concrete delivery.
The use of the washout site should be temporary (less than 1 year).
Should not be located in an area where shallow groundwater may be present,
such as near natural drainages, springs, or wetlands.
May be lined or unlined depending on site conditions.
Avoid natural drainage pathways, waterbodies, wells, and drinking water
sources.
Ensure adequate signage is in place for identifying the location of the washout
area.
Remove concrete waste in washout area as needed to maintain BMP function.
Collect concrete waste and deliver offsite to designated disposal location.
Vehicle Tracking Control
Provide stabilized construction site access where vehicles exit the site onto
paved public roads.
Helps remove sediment (mud or dirt) from vehicles, reducing tracking onto the
paved surface.
Particularly important during wet weather periods when mud is easily tracked off
site, dry weather periods where dust is a concern, and when poorly drained,
clayey soils are present.
Wheel washes may be needed on particularly muddy sites.
Inspect the area for degradation and replace material as needed.
Removed sediment that is tracked onto the public right of way daily or more
frequently as needed.
Excess sediment in the roadway indicates that maintenance is required.
Remove only when there is no longer the potential for vehicle tracking to occur.
2.2.2 Non-Structural Practices
Non-structural BMPs are both temporary and permanent stabilization practices. Such practices
may include surface roughening, temporary or permanent seeding, mulching, geotextiles and
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maintaining existing vegetation. The non-structural BMPs that will be used on the site include
the following:
Surface Roughening
Tracking, scarifying, tilling a disturbed area to provide temporary stabilization and
minimize wind and water erosion.
Not a stand-alone BMP and should be used with other BMP’s.
Temporary and Permanent Seeding
Soil preparation, disking, and soil amendments are necessary for proper seed
bed establishment.
Seeded areas should be inspected regularly. Areas that fail to establish shall be
re-seeded promptly.
Any area exposed for more than 30 days after construction has ceased shall be
seeded and mulched.
Permanent landscape cover shall be installed according to the landscape plan.
Mulching
Application of plant residues to the soil surface. Typical mulching materials
include certified weed free hay or straw, certified under the Colorado Department
of Agriculture Weed Free Forage Certification Program.
Utilized in combination with tackifier during high winds, steep slopes, or due to
seasonal constraints.
Used to cover permanent and temporarily seeded areas.
Inspect frequently and reapply in areas where mulching has loosened or
removed.
Maintain Existing Vegetation – Vegetated Buffers
Preserved natural vegetation helps protect waterways and wetlands from land
disturbing activities and improve stormwater runoff quality by straining sediment
and promoting infiltration.
Concentrated flow should not be directed through a vegetated buffer, instead
runoff should be in the form of sheet flow.
Used in conjunction with other perimeter control BMP’s such as sediment control
logs or silt fence.
Clearly delineate the boundary of the natural buffer area using construction or silt
fencing
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Construction Fence
Used to restrict site access to designated entrances and exits and delineates
construction site boundaries.
Used to protect natural areas or areas that should not be disturbed.
Construction fencing may be chain link or plastic mesh fencing.
Rolled Erosion Control Products:
A special blanket or liner that prevents erosion while vegetation is established
and aids in establishment by preserving moisture available to the seed.
The blankets need to cover the necessary area of the graded slope and bottom
channel.
The blanket will be installed according to the manufacturer’s instructions and
specifications. The number of staples or fasteners is critical while vegetation is
still germinating.
The erosion control blankets will be installed once the slopes of the vegetated
swales have reached final grade or on areas where erosion is occurring during
construction.
The erosion control blanket will be inspected weekly and immediately after storm
events to determine if cracks, tears, or breaches have been formed in the fabric.
If so, the blanket will be repaired or replaced immediately.
Good contact with the soil will be maintained and erosion will not occur under the
blanket. Any areas where the blanket is not in close contact with the ground will
be repaired or replaced.
Utilized as both temporary and permanent features depending on grade.
2.2.3 Other Controls
Vehicle Tracking Control/ Construction Entrance
A temporary stabilized layer of aggregate underlined with geotextile or gravel
located where traffic enters or exits the construction site.
Should be installed prior to any construction and inspected daily.
Does not work well alone in muddy conditions – use tire washing when mud is
present. Implementation of tire washing should include provisions for collecting
wash water and directing it to a treatment pond.
Whenever possible locate the construction entrance as far from the disturbed
area as possible to allow maximum travel time for sediment removal from tires.
Public and Private roadways shall be kept clear of accumulated sediment.
Cleaning sediment shall not be accomplished by flushing with water. Sediment
should be shoveled or swept from the street and placed away from storm water
improvements.
Consider limiting vehicles from entering the site when conditions are wet or
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muddy.
Wind Erosion / Dust Control
Dust from the site will be controlled using a mobile pressure-type distributor truck
to apply portable water to disturbed areas. The mobile unit will apply water only
as necessary to prevent runoff and ponding.
Dust control will be implemented as needed once site grading has been initiated
and during windy conditions while site grading is occurring.
Spraying of portable water will be performed whenever the dryness of the soil
warrants it.
At least one mobile unit will be available at all times to distribute portable water to
control dust in the project area.
During high winds, limit traffic speeds to 12 mph or less in areas without gravel or
pavement.
Gravel can be placed on construction roads, entrances, and construction staging
areas. Stone/gravel provides an effective protective cover over the soil.
In areas where wind erosion is expected soil-binding tackifiers can be applied
with high success.
Refer to Chapter 12 of the Code of the City of Fort Collins, Ordinance No. 044,
2016 for detailed requirements regarding fugitive dust.
Refer to the City of Fort Collins Dust Prevention and Control Manual.
Stabilized Staging Area
A clearly designated area where construction equipment and vehicles, waste
bins and other construction related materials are stored.
This area should be designated on the erosion control map.
Appropriate space to provide loading/unloading operations and parking.
A stabilized surface paved or covered in 3” diameter aggregate or larger.
Perimeter controls such as silt fence, sediment control logs or construction
fencing
Vehicle Tracking Control pad to be used in conjunction with a Stabilized Staging
Area if this area is adjacent to a public roadway.
Dewatering Operations
Dewatering typically involves pumping water from an inundated area to a BMP
and then downstream to a receiving waterway, sediment basin or vegetated
area. Dewatering typically involves the use of several BMPs in sequence.
All dewatering discharges must be treated to remove sediment before
discharging from a construction site. Discharging water into a sediment trap or
basin or filter bag, series of straw bales or sediment logs are options.
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Stockpile Management
Implement measures to minimize erosion and sediment transport from stockpiles.
Locate stockpiles away from all drainage system components.
Place BMPs around the perimeter of the stockpile such as sediment control logs,
rock socks, silt fence, straw bales and sandbags
For active use stockpiles, provide a stabilized access point upgradient of the
stockpile.
Surface roughening, temporary seeding and mulching, erosion control blankets
may be needed for stockpiles older than 30 days.
2.2.4 Installation and Removal Sequence of Control Measures
The following sequencing chart provides a general overview of the expected installation and
removal of control measures for each phase of construction.
MOBILIZATION DEMOLITION GRADING
UTILITIES
INSTALLATION
FLAT WORK
INSTALLATION LANDSCAPE DEMOBILIZATION
BEST MANAGEMENT PRACTICS (BMPs)
SILT FENCE BARRIERS
VEHICLE TRACKING PAD
FLOW BARRIERS (WATTLES)
INLET PROTECTION Any prior inlets that could use protecting.
RIP RAP
COLLECTING ASPHALT / CONCRETE SAW CUTTING WASTE
VEGETATIVE
TEMPORARY SEEDING PLANTING Any time the site will sit dorment longer than 30 days.
MULCHING/SEALANT Any time the site will sit dorment longer than 30 days.
PERMANENT SEEDING PLANTING
SOD INSTALLATION
ROLLED PRODUCTS: NETTING/BLANKETS/MATS Any time the site will sit dorment longer than 30 days.
Montava Subdivision Phase D is to be constructed in a single phase, and it is the contractor’s
responsibility to ensure proper control measure practices for any disturbed areas of the site
throughout the entire construction process.
2.3 Materials Management
2.3.1 Potential Pollution Sources
Abnormal or especially hazardous materials are not expected to be utilized during the
construction of the project, but like most construction projects, some materials or substances
used have the potential to be hazardous when leaked into the storm water runoff. The following
potential pollutant sources are to be evaluated on every project:
1. All disturbed and stored soils
2. Vehicle tracking of sediments
3. Management of contaminated soils
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4. Loading and unloading operations
5. Outdoor storage of construction materials, building materials, fertilizers, and chemicals
6. Bulk storage materials
7. Vehicle and equipment maintenance and fueling
8. Significant dust or particulate generating processes. It is important to reference the
Fugitive Dust Control Ordinance No. 044, 2016, §12-150 - §12-160 and the projects
requirements to be in compliance with that ordinance.
9. Routine maintenance activities involving fertilizers, pesticides, detergents, fuels,
solvents, and oils
10. On-site waste management practices
11. Concrete truck/equipment washing, including the concrete truck chute and associated
fixtures and equipment
12. Dedicated asphalt and concrete batch plants
13. Non-industrial waste sources such as worker trash and portable toilets
14. Saw cutting and grinding
15. Other non-stormwater discharges including construction dewatering not covered under
the Construction Dewatering Discharges general permit and wash water that may
potentially contribute pollutants to the MS4
16. Other areas or operations where spills can occur
As construction progresses, specific areas shall be designated for the above-mentioned
activities and materials management operations. The contractor is responsible for marking the
location of these facilities on the site map and reporting on the condition, effectiveness and
corrections or changes made and why.
2.3.2 Pollution Prevention Measures
Pollution prevention measures should be utilized to prevent construction materials with the
potential for polluting storm water from coming in contact with runoff. Measures include good
housekeeping, proper disposal and storage, spill prevention, and secondary containment.
BMPs for most common construction materials and wastes with the greatest potential for
adversely affecting water quality are as follows:
Montava Subdivision Phase D Erosion Control Report
Page 15
BMPs for Construction Waste:
Select a designated waste collection area onsite.
Locate containers in level areas away from storm water conveyance structures.
Provide covers for containers that contain very hazardous or soluble chemicals.
Avoid putting paint/solvent containers in open dumpsters or allow them to dry
completely before disposing.
If a container does spill, provide clean up immediately.
Make sure waste is disposed of at authorized disposal areas.
BMPs for Hazardous Waste Disposal
Check with local waste management authorities with regard to requirements for
disposing of hazardous materials.
Use entire product before disposing.
Dispose of containers with lids on and tightly sealed
Provide a separate dumpster for large amounts of chemical or hazardous
material and maintain more stringent controls on that dumpster.
Do not remove the product label from containers, it contains important disposal
information.
BMPs for Sanitary/Septic Wastes
If self-contained, temporary sanitary facilities are used, the waste disposal
company should service the facilities based on the number of workers anticipated
to avoid overuse.
All facilities should be anchored to the ground to prevent overturning due to wind
or accident.
Locate portable toilets away from curbs, swales or other locations where
concentrated runoff may occur.
Do not dump any hazardous materials into the sanitary waste disposal systems.
BMPs for pesticides/fertilizers
Store pesticides in a dry covered area and elevate above the ground.
Provide secondary containment barriers around areas where a lot of material is
stored. Straw Wattles are NOT appropriate containment barriers!
Strictly follow recommended application rates and application methods
Apply fertilizer more frequently and at lower rates.
Reduce exposure of nutrients to storm events by working fertilizer deep into soil
BMPs for petroleum products
Fueling operations shall occur in a designated area.
Montava Subdivision Phase D Erosion Control Report
Page 16
Store petroleum products in covered areas and away from areas where
concentrated runoff occurs.
Provide secondary containment barriers around areas where a lot of material is
stored. Straw Wattles are NOT appropriate containment barriers!
Schedule preventative maintenance for onsite equipment and fix any gas/oil
leaks on a regular basis.
Follow procedures for proper handling of asphalt and sealers.
Secure fueling equipment and install valves to prevent vandalism/theft.
2.4 Spill Management
Construction site supervisors should create and adopt a spill control plan that includes
measures and procedures to stop the source of the spill, contain the spill, clean up, and dispose
of contaminated materials. Key personnel should be identified and trained to be responsible for
spill prevention and control. The following measures would be appropriate for a spill prevention
response plan:
Store and handle materials to prevent spills
Tightly seal containers.
Make sure all containers are neatly labeled.
Stack containers carefully for stability to avoid spills.
Limit the height of stacks of stored materials.
Whenever possible store materials on covered pallets or in trailers with adequate
ventilation.
Eliminate storm water contact if there is a spill.
Have cleanup procedures clearly posted.
Have cleanup materials readily available and posted.
Immediately contain any liquid.
Stop the source of the spill.
Cover spill with absorbent material and dispose of properly.
Additionally, records of spills, leaks, or overflows that result in the discharge of pollutants must
be documented and maintained.
When any spill occurs:
1) Notify the controlling operator of the site immediately following a hazardous spill.
2) Document the spill and its clean-up procedures whether reporting is required or not.
3) At a minimum document the following:
Nature of spill
Quantity of spill
Montava Subdivision Phase D Erosion Control Report
Page 17
Date/time spill occurred
Agency notification if necessary
Clean-up procedures used
Daily monitoring (7 days) after clean-up
Photographs
Interview(s) with any witnesses of the event
Some spills will need to be reported to the Division of Water Quality immediately including the
following:
Over 25 gallons of petroleum
5 CCs of mercury
a release of any chemical, oil, petroleum product which entered waters of the State of
Colorado (which include surface water, groundwater, dry gullies or storm sewers leading
to surface water).
Any spill or release of raw sewage
If any of the above criteria is met or exceeded, the Colorado Department of Public Health and
Environment, Local Emergency Planning committee, downstream users and other agencies
(MS4s) will be notified. The CDPHE will be notified by telephone within 24 hours. In addition,
written notification describing the spill and the cleanup procedures used will be sent to the
agencies 5 days following the spill. If a spill does not meet the above criteria, reporting is not
mandatory. The Division’s 24-hour environmental emergency spill reporting line is 1-877-518-
5608.
2.5 Non-Storm Water Components of Discharge
Non-storm water discharges must be avoided or reduced to the maximum extent possible. This
Erosion Control Report assumes construction dewatering will be required. Pumping or draining
groundwater, even groundwater that has infiltrated an excavation, requires a separate permit
from the State. Storm water that mixes with groundwater is also subject to the controls in the
general permit for Construction Dewatering. The permit requirements and application for
Construction dewatering is available at:
http://www.cdphe.state.co.us/wq/PermitsUnit/construction.html.
No materials shall be discharged in quantities that may impact storm water runoff. Possible
discharge sources that need to be contained include:
Locations where water tanks are being filled. Seal all leaks and avoid over filling. Any
leaks should be directed to a water quality pond or protected to prevent erosion.
Contain excess water during fire hydrant blow off, water system cleaning or other
Montava Subdivision Phase D Erosion Control Report
Page 18
instances where potable water is discharged onto the surface. Convey any discharge to
a water quality pond and avoid causing erosion by avoiding steep slopes, disturbed
areas, etc.
Monitor irrigation systems and fix leaks promptly. Avoid over-irritating areas where
vegetation is not yet established.
3.0 - Maintenance and Inspection Requirements
3.1 Inspection and Maintenance Overview
A site inspection of all erosion control facilities shall be conducted at least once every two
weeks and immediately following any significant storm event, including snowmelt that can cause
surface erosion and at least every 30 days for inactive projects. The inspection must determine
if there is any evidence of, or the potential for, pollutants entering the drainage system. BMPs
should be inspected to see if they meet the design and operation criteria in the Erosion Control
Report and that they are adequately controlling potential pollutants. Any defects shall be
corrected promptly. Where spill kits have been used, or storage areas moved, supplies shall be
restocked and re-protected. The site shall be inspected by the Erosion Control Administrator or
someone with adequate training who should monitor and follow the procedures outlined below:
3.2 Minimum Monitoring Requirements
Inspections of the site shall be conducted by the contractor (or agent) every two weeks
and after significant storm events.
Inspections are required at least every 30 days and after measurable storm events for
sites that are no longer under construction, but do not have 70% established ground
cover.
A qualified superintendent familiar with this report and BMPs shall perform the
inspections.
The contractor shall certify that the site is in compliance with the permit by:
Ensuring areas where significant runoff is occurring are identified on the site map.
Storm water outfall shall be observed to determine whether or not measurable quantities
of sediment or other pollutants have been or are being transported offsite.
BMPs shall be addressed to determine if they are functioning properly or if they are in
Montava Subdivision Phase D Erosion Control Report
Page 19
need of repair or maintenance. If the report describes deficiencies in pollution control
structures or procedures, such deficiencies shall be corrected immediately.
A brief description of measures taken to correct deficiencies shall be recorded.
Determine if additional controls will be needed to next week’s activities.
When an inspection does not identify any incidents of non-compliance, the report shall
contain a certification that the site is in compliance with the Erosion Control Report and
this permit.
The date and inspector identity shall also be recorded. This record shall be signed and
made available to the State or City upon request.
Based on the results of the inspection, the description of potential pollutant sources, and the
control measures used should be updated on the Erosion Control Report and Site Maps as
soon as possible. Typically, corrective action shall commence immediately when a deficiency is
observed. Erosion Control Report and Map updates shall be completed within 72 hours.
Another inspection should follow up and include the date, corrective action taken, and initials of
who certified the work. For more information regarding installation, maintenance, and removal
for each control measure, see Appendix C.
3.3 Reporting Requirements / Inspection Reports
The contractor is responsible for reporting all BMP inspections and maintaining records
of reports and maps throughout the project. The record shall be retained onsite and/or
readily available until the inactivation notice has been filed. All inspection reports shall
be submitted to the owner when the permit becomes inactive. At a minimum, the
inspection reports shall contain the following:
Dates
Name(s) of inspectors
Purpose of inspection e.g. spill event, leakage of materials, storm event, bi-
weekly inspection, etc.
When a bi-weekly report, an assessment of the entire property as related to
erosion control issues
An estimated area of currently disturbed area.
Evaluation of all active BMPs
Actions needed to assure continued compliance with erosion control guidelines
Document all areas of potential pollution sources and how they are protected
Documentation of any needed changes
Training events
Uncontrolled releases of mud or muddy water or measurable amounts of
Montava Subdivision Phase D Erosion Control Report
Page 20
sediment
An estimated amount of precipitation. An onsite rain gauge is suggested.
3.4 Site Maps
In the back pocket of this report notebook there is an Erosion Control Plan for use during
construction. The purpose of this plan is to provide the contractor with a place to document and
plan BMPs used during construction. Because the placement of individual BMP’s will depend
on the condition of the site and the contractor’s judgment, not all BMPs are shown on the plans.
It is the contractor’s duty as site administrator to determine the need for and placement of BMPs
and mark them on the map.
4.0 - Final Vegetation and Stabilization / Conclusion
Permanent stabilization will be achieved by establishing vegetative or permanent surface cover
on all disturbed areas. The final vegetative cover is specified on the Erosion Control Plan. The
contractor is responsible for using approved landscape plans according to the City Landscape
Standards (LUC 3.2.1). Soil shall be prepared in accordance with Fort Collins Municipal Code
§12-132. The City of Fort Collins considers vegetative cover complete when the plant density
reaches 70 percent.
The contractor shall remove all temporary erosion and sediment control BMPs after stabilization
is achieved or after temporary BMPs are no longer needed. Trapped sediment (including within
pipes) will be removed by the contractor or stabilized onsite. Disturbed soil areas resulting from
removal of BMPs, or the contractor will permanently stabilize vegetation as soon as possible.
Again, this plan is a living document that will need to be updated and maintained
throughout the construction process and until all areas of the site have been stabilized.
This permit will remain active until an inactivation notice has been filed with the State.
Additionally, this permit may be transferred to another party in the event that the contractor or
sub-contractor responsible for its implementation leaves the site before stabilization has
occurred.
Montava Subdivision Phase D Erosion Control Report
Page 21
5.0 - References
1. CDOT Erosion Control and Storm Water Quality Guide, Colorado Department of
Transportation, 2002
2. Urban Storm Drainage Criteria Manual, Urban Drainage and Flood Control District (Rev.
July 2001)
3. Storm Water Risk Management, LLC; April 11, 2008; Pre-Construction & Engineering
Training for Construction Storm Water Management Manual.
4. Construction Site Storm Water Runoff Control – National Menu of best practices, U.S.
Environmental Protection Agency, 1999
APPENDIX A
FINAL SUBSURFACE EXPLORATION REPORT
FINAL SUBSURFACE EXPLORATION REPORT
MONTAVA DEVELOPMENT- PHASE D
APPROXIMATE 40-ACRE MIXED USE DEVELOPMENT
NORTHWEST CORNER OF MOUNTAIN VISTA DRIVE AND NORTH GIDDINGS ROAD
FORT COLLINS, COLORADO
EEC PROJECT NO. 1172058
Prepared for:
Montava Development, LLC
430 N College Avenue, Suite 410
Fort Collins, Colorado 80524
Attn: Mr. Max Moss (Max@hf2m.com), and
Mr. Forrest Hancock (forrest@montava.com)
Development Director
Earth Engineering Consultants, LLC
4396 Greenfield Drive
Windsor, Colorado 80550
4396 G REENFIELD D RIVE
W INDSOR , C OLORADO 80550
(970) 545-3908 FAX (970) 663-0282
April 22, 2024
Montava Development, LLC
430 N College Avenue, Suite 410
Fort Collins, Colorado 80524
Attn: Mr. Max Moss (Max@hf2m.com), and
Mr. Forrest Hancock (forrest@montava.com)
Development Director
Re: Final Subsurface Exploration Report
Montava Development – Phase D - Approximate 40+ Acre Mixed Use Development
Northwest Corner of Mountain Vista Drive and North Giddings Road
Fort Collins, Larimer County, Colorado
EEC Project No. 1172058
Mr. Moss and Mr. Hancock:
Enclosed, herewith, are the results of the supplemental preliminary (FINAL) subsurface exploration
completed by Earth Engineering Consultants, LLC personnel for the referenced project. A total of
seventeen (17) preliminary soil borings were drilled on April 2 and 5, 2024 at the approximate locations
as indicated on the enclosed Boring Location Diagrams included with this report. The borings were
extended to depths of approximately 15½ to 25½ feet below existing site grades. Individual boring logs,
including groundwater observations, and results of laboratory testing are included as a part of the
attached report. It should be noted that in 2017, Earth Engineering Consultants, LLC (EEC) conducted
a preliminary subsurface exploration for the overall 800-acre site by drilling a series of thirty (30) test
borings throughout the property and preparing a report with our findings. For further information and
preliminary recommendations based on the 2017 subsurface exploration, please refer to our Preliminary
Subsurface Exploration Report dated October 2, 2017, EEC Project No. 1172058. Three (3) borings
during the initial preliminary subsurface exploration, (borings B-6, B-12, and B-13) were generally
located within the Phase D development as indicated with blue color on the enclosed Boring Location
Diagrams. This exploration was completed in general accordance with our proposal dated March 13,
2024.
In summary, the subgrades underlying the surficial vegetation/topsoil generally consisted of cohesive
soils classified as lean clay with varying amounts of sand extending to the bottom of the completed
borings at borings B-13 and B-17, approximately 15 and 15½, respectively, below the existing ground
surface or to the underlying granular materials at approximate depths of 7 to 16 feet below the ground
surface at the remining borings. The lean clay to sandy lean clay soils were generally dry to moist to
wet, very soft to very stiff, and exhibited nil to low swell potential with a slight tendency to hydro-
FINAL SUBSURFACE EXPLORATION REPORT
MONTAVA DEVELOPMENT- PHASE D
APPROXIMATE 40-ACRE MIXED USE DEVELOPMENT
NWC OF MOUNTAIN VISTA DRIVE AND NORTH GIDDINGS ROAD
FORT COLLINS, COLORADO
EEC PROJECT NO. 1172058
April 22, 2024
INTRODUCTION
The supplemental preliminary (FINAL) subsurface exploration for the proposed approximate 40-
acre mixed used – Montava Development, Phase D, located at the northwest corner of Mountain
Vista Drive and North Giddings Road, in north Fort Collins, Colorado has been completed. For
this exploration, a total of seventeen (17) supplemental preliminary soil borings were drilled on
April 2 and April 5, 2024, at the approximate locations as indicated on the enclosed Boring
Location Diagrams included with this report. The seventeen (17) supplemental preliminary soil
borings were advanced to depths of approximately 15 to 25½ feet below existing site grades across
the proposed development property to obtain information on existing subsurface conditions. Upon
completion of the drilling operations, six (6) of the open bore holes were converted to temporary
PVC cased piezometers. Additionally, information from a preliminary subsurface exploration
completed by EEC dated October 2, 2017, EEC Project No. 1172058, was available to us which
was referenced for preparation of this report. Three (3) borings during the initial preliminary
subsurface exploration, (boring B-6 B-12 and B-13) were generally located within the Phase D
development as indicated with blue color on the enclosed Boring Location Diagrams. Individual
boring logs and site diagrams indicating the approximate boring locations of the three (3) October
2017 and current borings, are included with this report.
We understand Phase D of the overall Montava Development is currently in the planning/design
process for single-family residential, duplex, townhomes, and mixed-use development as depicted
on the enclosed site plans provided to us by Montava Development, LLC personnel on March 11,
2024. Foundation loads for the proposed structures are anticipated to be light to moderate with
continuous wall loads less than 4 kips per lineal foot and individual column loads less than 250
kips. Floor loads are expected to be light. We anticipate maximum cuts and fills on the order of
approximately 5 feet (+/-) in general site areas. Overall site development will include construction
of associated pavements designed in general accordance with the Larimer County Urban Area
Street Standards (LCUASS) Pavement Design Criteria.
Earth Engineering Consultants, LLC
EEC Project No. 1172058
April 22, 2024
Page 2
The purpose of this report is to describe the subsurface conditions encountered in the supplemental
preliminary borings, analyze and evaluate the test data and provide preliminary geotechnical
recommendations concerning site development including foundations, interior floor slabs, exterior
flatworks as well as pavement sections and the possibility for an area underdrain system to support
basement/underpass construction.
EXPLORATION AND TESTING PROCEDURES
The preliminary boring locations were established in the field by representatives from EEC by
pacing and estimating angles from identifiable site features with the aid of a hand-held GPS unit
using appropriate Google Earth Coordinates. Those approximate boring locations are indicated
on the attached “Boring Location Diagrams.” The location of the borings should be considered
accurate only to the degree implied by the methods used to make the field measurements.
The borings were performed using a truck mounted, CME-55 drill rig equipped with a hydraulic
head employed in drilling and sampling operations. The boreholes were advanced using 4-inch
nominal diameter continuous flight augers. Samples of the subsurface materials encountered were
obtained using split-barrel and California barrel sampling techniques in general accordance with
ASTM Specifications D1586 and D3550, respectively.
In the split-barrel and California barrel sampling techniques, standard sampling spoons are driven
into the ground by means of a 140-pound hammer falling a distance of 30 inches. The number of
blows required to advance the samplers is recorded and is used to estimate the in-situ relative
density of cohesionless materials and, to a lesser degree of accuracy, the consistency of cohesive
soils and hardness of weathered bedrock. In the California barrel sampling procedure, samples of
the subsurface soils are obtained in removable brass liners. All samples obtained in the field were
sealed and returned to our laboratory for further examination, classification and testing.
Laboratory moisture content tests were performed on each of the recovered samples. In addition,
the unconfined strength of appropriate samples was estimated using a calibrated hand
penetrometer. Washed sieve analysis and Atterberg limits tests were completed on select samples
to evaluate the quantity and plasticity of the fines in the subgrade soils. Swell/consolidation tests
were completed on select samples to evaluate the potential for subgrade materials to change
volume with variation in moisture content and load. Water-soluble sulfate tests were performed
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EEC Project No. 1172058
April 22, 2024
Page 3
on select samples to evaluate potential adverse reactions to site-cast concrete. Results of the
outlined tests are indicated on the attached boring logs and summary sheets.
As part of the testing program, all samples were examined in the laboratory and classified in
general accordance with the attached General Notes and the Unified Soil Classification System,
based on the soil’s texture and plasticity. The estimated group symbol for the Unified Soil
Classification System is indicated on the boring logs and a brief description of that classification
system is included with this report.
SITE AND SUBSURFACE CONDITIONS
The proposed improvement area is generally located at the northwest corner of Mountain Vista
Drive and North Giddings Road in north Fort Collins, Colorado. Topsoil and vegetation/weeds
were encountered at the surface of the completed test borings. The proposed improvement areas
were relatively flat with an approximate relief of 10 feet across the site. Photographs of the site
taken at the time of drilling are provided with this report.
An EEC field engineer was on site during drilling to evaluate the subsurface conditions
encountered and direct the drilling activities. Field logs prepared by EEC site personnel were
based on visual and tactual observation of disturbed samples and auger cuttings. The final boring
logs included with this report may contain modifications to the field logs based on the results of
laboratory testing and evaluation. Based on the results of the field borings and laboratory
evaluation, subsurface conditions can be generalized as follows.
In summary, the subgrades underlying the surficial vegetation/topsoil generally consisted of
cohesive soils classified as lean clay with varying amounts of sand extending to the bottom of the
completed borings at borings B-13 and B-17, approximately 15 and 15½, respectively, below the
existing ground surface or to the underlying granular materials at approximate depths of 7 to 16
feet below the ground surface at the remining borings. The lean clay to sandy lean clay soils were
generally dry to moist to wet, very soft to very stiff, and exhibited nil to low swell potential with
a slight tendency to hydro-compact at current moisture and density conditions. Silty sand /sand
with varying amounts of silt and gravel was encountered below the upper cohesive soils and
extended to the bottom of the completed borings, approximately 15 to 25½ feet below existing
Earth Engineering Consultants, LLC
EEC Project No. 1172058
April 22, 2024
Page 4
ground surface. The granular soils were generally loose to dense and are expected to have nil to
low swell potential.
The stratification boundaries indicated on the boring logs represent the approximate locations of
changes in soil types. In-situ, the transition of materials may be gradual and indistinct.
GROUNDWATER CONDITIONS
Observations were made while drilling, after drilling and on April 9 and 22, 2024, within the
installed temporary piezometers, to detect the presence and level of groundwater. At the time of
drilling and on follow up dates mentioned, groundwater was observed in all of the preliminary test
borings except boring B-17 at depths ranging from approximately 2½ to 11 feet below the existing
ground surface. The measured depths to groundwater are recorded near the upper right-hand
corner of each boring log included with this report. The groundwater measurements provided with
this report are indicative of groundwater levels at the location and at the time the measurements
were completed. The groundwater directional flow is generally in the south direction.
Perched and/or trapped water may be encountered in more permeable zones in the subgrade soils
at times throughout the year. Perched water is commonly encountered in soils immediately
overlying less permeable bedrock materials. Fluctuations in ground water levels and in the
location and amount of perched water may occur over time depending on variations in hydrologic
conditions, irrigation activities on surrounding properties and other conditions not apparent at the
time of this report.
ANALYSIS AND RECOMMENDATIONS
Swell – Consolidation Test Results
The swell-consolidation test is performed to evaluate the swell or collapse potential of soils to help
determine foundation, floor slab and pavement design criteria. In this test, relatively undisturbed
samples obtained directly from the California sampler are placed in a laboratory apparatus and
inundated with water under a predetermined load. The swell-index is the resulting amount of swell
or collapse after the inundation period expressed as a percent of the sample’s preload/initial
Earth Engineering Consultants, LLC
EEC Project No. 1172058
April 22, 2024
Page 5
thickness. After the inundation period, additional incremental loads are applied to evaluate the swell
pressure and/or consolidation.
For this analysis, we conducted eighteen (18) swell-consolidation tests. The (+) test result
indicates the material’s swell potential while the (-) test result indicates the material’s slight
collapse potential when inundated with water. The following table summarizes the swell-
consolidation laboratory test results.
Table I – Laboratory Swell-Consolidation Test Results Building and Pavement Borings
No of
Samples
Tested
Pre-Load /
Inundation
Pressure,
PSF
Description of Material
In-Situ Characteristics
Range of Swell – Index
Test Results Moisture
Contents, %
Range of Dry Densities,
PCF
End,
%
End,
%
Low End,
PCF
High End,
PCF
Low End
(+/-) %
High End,
(+/-) %
4 150 Lean Clay (CL) 24.8 45.6 76.2 98.0 (-) 1.9 (+) 0.3
14 500 Or Silty Sand (SC) 16.8 41.0 79.7 106.4 (-) 1.1 0.0
Colorado Association of Geotechnical Engineers (CAGE) uses the following information to provide
uniformity in terminology between geotechnical engineers to provide a relative correlation of slab
performance risk to measured swell. “The representative percent swell values are not necessarily
measured values; rather, they are a judgment of the swell of the soil and/or bedrock profile likely to
influence slab performance.” Geotechnical engineers use this information to also evaluate the swell
potential risks for foundation performance based on the risk categories.
TABLE II -Recommended Representative Swell Potential Descriptions and Corresponding
Slab Performance Risk Categories
Slab Performance Risk Category Representative Percent Swell
(500 psf Surcharge)
Representative Percent Swell
(1000 psf Surcharge)
Low 0 to < 3 0 < 2
Moderate 3 to < 5 2 to < 4
High 5 to < 8 4 to < 6
Very High > 8 > 6
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EEC Project No. 1172058
April 22, 2024
Page 6
Based on the laboratory test results, samples of the overburden subsoils analyzed were within the
nil to low range of swell risk category with a tendency to hydro-compact when inundated with
water, and a tendency to consolidate with increased loads.
General Considerations
General guidelines are provided below for the site subgrade preparation. However, it should be
noted that compaction and moisture requirements vary between builders/owners and,
consequently, between geotechnical engineering companies. If the development lots will be
marketed to a target group of builders, fill placement criteria should be obtained from those
builders and/or their geotechnical engineering consultants prior to beginning earthwork activities
on the site. Representatives from those entities should verify that the fill is being placed consistent
with the home builders’ guidelines.
The near surface cohesive soils were generally dry to wet, very soft to very stiff, exhibited nil to
low plasticity and nil to low swell characteristics along with a tendency to hydro-compact at
current moisture and density conditions. If the overburden soils were to become wetted subsequent
to construction of overlying improvements, settlements caused by soft/compressible overburden
soils could result in significant total and differential movement of site improvements. Therefore,
preliminary considerations and/or recommendations for an over excavation and replacement
concept to reduce the potential movement of foundations, floor slabs, and pavements, are included
herein. However, specific over-excavation depths and methods of reducing the potential for
movement are to be determined by the individual/lot-specific builder.
Groundwater was observed at depths of 2½ to 16 feet below the ground surface in the borings.
Depending on final site grades, we suggest that floor slab subgrade(s) be placed a minimum of 4
feet above the maximum anticipated rise in groundwater levels. If final site grading consists of
cuts extending footings and floor slabs to less than 4 feet above the maximum anticipated rise in
groundwater, consideration could be given to designing and installing interior perimeter drainage
systems and/or elevating/raising the site grades to establish the minimum required 4-foot
separation to the maximum anticipated rise in groundwater.
Earth Engineering Consultants, LLC
EEC Project No. 1172058
April 22, 2024
Page 7
Site Preparation
All existing vegetation and/or topsoil should be removed from beneath site fills, roadways or
building subgrade areas. Stripping depths should be expected to vary, depending on current
surface elevations. In addition, any soft/compressible native soils, or any existing fill materials
without documentation of controlled fill placement should be removed from improvement and/or
new fill areas.
After stripping and completing all cuts and prior to placement of any fill, floor slabs or pavements,
we recommend the exposed soils be scarified to a minimum depth of 9 inches, adjusted in moisture
content and compacted to at least 95% of the material's maximum dry density as determined in
accordance with ASTM Specification D698, the standard Proctor procedure. The moisture content
of the scarified materials should be adjusted to be within a range of ±2% of standard Proctor
optimum moisture at the time of compaction.
In general, fill materials required to develop the building areas or site pavement subgrades should
consist of approved, low-volume change materials which are free from organic matter and debris.
The near surface lean clay and/or sand/silty sand soils could be used as fill in these areas. We
recommend the fill soils be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture
content and compacted to at least 95% of the material’s maximum dry density as determined in
accordance with the standard Proctor procedure. The moisture content of predominately clay soils
should be adjusted to be within the range of ±2% of optimum moisture content at the time of
placement. Granular soil should be adjusted to a workable moisture content.
The near surface clay soils will be subject to strength loss and instability when wet. Pumping of
the subgrades should be expected if the subgrades become wet before placement of overlying
pavements. In addition, the site soils may be subject to frost heaving with available moisture and
freezing temperatures. Positive drainage to prevent ponding of water in the site, including ponding
of snow melt, should be developed to reduce the potential for post construction frost heaving.
Care should be exercised after preparation of the subgrades to avoid disturbing the subgrade
materials. Positive drainage should be developed away from the structures and pavements to avoid
wetting of subgrade materials. Subgrade materials becoming wet subsequent to construction of
the site improvements can result in unacceptable performance.
Earth Engineering Consultants, LLC
EEC Project No. 1172058
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Page 8
Foundation Systems – Preliminary General Considerations
The overburden soils require particular attention in the design and construction to reduce the amount
of movement/differential movement due to the in-situ characteristics. The following foundation
system was evaluated for use on the site; however, final subsurface explorations should be performed
after building footprints and elevations have been better defined and actual design loads determined
and better determine the depth of over-excavation:
• Spread Footing foundations bearing on approved fill material. If spread footings are chosen,
the depth of any required over excavation and replacement or improvement of the cohesive
soils should be considered below the bottom of the footings during the supplemental/lot-
specific subsurface exploration phase. If greater potential for movement cannot be tolerated,
alternative foundation systems such as drilled pier foundations could be used. All footings
should bear on a uniform zone of material to minimize the potential of differential movement
of dissimilar soils.
Should other alternative foundation systems be considered, we would be pleased to provide
additional recommendations upon request.
Preliminary Floor Slab/Exterior Flatwork Subgrades
We recommend all existing vegetation/topsoil be removed from beneath the floor slab and exterior
flatwork areas as previously outlined. After stripping and completing all cuts and prior to
placement of any flatwork concrete or fill, the exposed subgrades should be scarified, adjusted in
moisture content and compacted. If the subgrades become dry and desiccated prior to floor slab
construction, it may be necessary to rework the subgrades prior to floor slab placement.
Fill soils required to develop the floor slab subgrades should consist of approved, low-volume
change materials which are free from organic matter and debris. Those fill materials should be
placed as previously outlined and surcharged/preloaded and/or monitored as necessary to limit
total and differential movement after construction of overlying improvements.
Earth Engineering Consultants, LLC
EEC Project No. 1172058
April 22, 2024
Page 9
Preliminary Basement Design and Construction
With the exception of boring B-17, groundwater was encountered across the site within the
supplemental preliminary soil borings at approximate depths of 2-1/2 to 11 feet below existing site
grades. If lower-level construction for either garden-level or full-depth basements is being
considered for the site, we would suggest that the lower-level subgrade(s) be placed a minimum
of 4 feet above maximum anticipated rise in groundwater levels, and a combination exterior and
interior perimeter drainage system(s) be installed.
Consideration could be given to 1) either designing and installing an area wide underdrain system
to lower the groundwater levels provided a gravity discharge point can be established. If a gravity
outlet/system cannot be designed another consideration would be to designing and installing a
mechanical sump pump system to discharge the collected groundwater within the underdrain
system, or 2) elevate/raise the site grades to establish the minimum required four (4) foot separation
to the maximum anticipated rise in groundwater. EEC is available to assist in the underdrain
design if requested.
The following information should also be considered, as previously mentioned, and would be to
install an interior and exterior perimeter drainage system for each individual residence. To reduce
the potential for groundwater to enter the lower level/basement area of the structure(s), installation
of a dewatering system is recommended. The dewatering system should, at a minimum, include
an under-slab gravel drainage layer sloped to an interior perimeter drainage system. The following
provides preliminary design recommendations for interior and exterior perimeter drainage
systems.
The under-slab drainage system should consist of a properly sized perforated pipe, embedded in
free-draining gravel, placed in a trench at least 12 inches in width. The trench should be inset from
the interior edge of the nearest foundation a minimum of 12 inches. In addition, the trench should
be located such that an imaginary line extending downward at a 45-degree angle from the
foundation does not intersect the nearest edge of the trench. Gravel should extend a minimum of
3 inches beneath the bottom of the pipe. The under-slab drainage system should be sloped at a
minimum of 1/8 inch per foot to a suitable outlet, such as a sump and pump system.
Earth Engineering Consultants, LLC
EEC Project No. 1172058
April 22, 2024
Page 10
The under-slab drainage layer should consist of a minimum 6-inch thickness of free-draining
gravel meeting the specifications of ASTM C33, Size No. 57 or 67 or equivalent. Cross-
connecting drainage pipes should be provided beneath the slab at minimum 15-foot intervals and
should discharge to the perimeter drainage system.
Sizing of drainage pipe will be dependent upon groundwater flow into the dewatering system.
Groundwater flow rates will fluctuate with permeability of the soils to be dewatered and the depth
to which groundwater may rise in the future. Pump tests to determine groundwater flow rates are
recommended in order to properly design the system. For preliminary design purposes, the
drainage pipe, sump and pump system should be sized for a projected flow of 0.5 x 10-3 cubic feet
per second (cfs) per lineal foot of drainage pipe. Additional recommendations can be provided
upon request and should be presented in final subsurface exploration reports for each residential
lot.
Preliminary Pavement Subgrades
Fill materials required to develop the pavement subgrades should consist of approved, low-volume
change materials, free from organic matter and debris. Imported structural fill materials similar to
CDOT Class 5, 6 or 7 base course material could be used in these areas. We recommend those fill
soils be placed as recommended in the Site Preparation section of this report.
The essentially cohesive soils may show strength loss and instability when wetted. Stabilization
of those subgrades could be necessary at the time of construction to develop a stable platform for
subsequent paving. Stabilization could be predesigned into the subgrades to mitigate swell, and
the stabilized subgrades would be considered a part of the pavement section. Consideration could
be given to a fly ash treatment concept for swell mitigation and/or stabilization, should pumping
conditions develop.
If a subgrade stabilization concept is chosen/required, consideration could be given to
incorporating Portland cement / Class C fly ash within the upper 12-inches of the site pavements
prior to construction of the overlying pavement structure. Stabilization should consist of blending
4% and 13% by dry weight of Portland cement and Class C fly ash, respectively, in the top 12
inches of the subgrades. The blended materials should be adjusted in moisture content to slightly
dry of standard Proctor optimum moisture content and compacted to at least 95% of the material’s
Earth Engineering Consultants, LLC
EEC Project No. 1172058
April 22, 2024
Page 11
maximum dry density as determined in accordance with the standard Proctor procedure.
Compaction of the subgrade should be completed within two hours after initial blending of the
Class C fly ash.
Pavement sections are based on assumed traffic volumes and subgrade strength characteristics.
Based on the materials encountered, we believe an estimated R-value of 10 would be appropriate
for design of the pavements supported on the subgrade soils. Suggested preliminary pavement
sections for the light duty and heavy-duty on-site pavement improvement sections are provided
below in Table III. A final pavement design thickness evaluation will be determined when a
pavement design exploration is completed (after subgrades are developed to ± 6 inches of design
and wet utilities installed).
Hot mix asphalt (HMA) underlain by aggregate base course, or a non-reinforced concrete
pavement may be feasible options for the proposed on-site paved sections. HMA pavements may
show rutting and distress in areas of heavy truck traffic or in truck loading and turning areas.
Concrete pavements should be considered in those areas.
Table III – Preliminary Pavement Sections
Local Residential
Roadways Roadways
EDLA – assume local residential roadways
Reliability
Resilient Modulus
PSI Loss – (Initial 4.5, Terminal 2.0 and 2.5 respectively)
75%
3562
2.2
85%
3562
2.2
Hot Mix Asphalt (HMA) Grading S (75) PG 58-28
Aggregate Base Course ABC – CDOT Class 5 or 6
Design Structure Number
4ʺ
8ʺ
(2.64)
5-1/2ʺ
8ʺ
(3.30)
Hot Mix Asphalt (HMA) Grading S (75) PG 58-28
Aggregate Base Course ABC – CDOT Class 5 or 6
Fly Ash Treated Subgrade
Design Structure Number
4ʺ
6 ʺ
12″
(3.02)
4ʺ
8ʺ
12ʺ
(3.24)
1/2″7″
Earth Engineering Consultants, LLC
EEC Project No. 1172058
April 22, 2024
Page 12
Asphalt surfacing should consist of grading S-75 or SX-75 hot bituminous pavement with PG 64-
22 or PG 58-28 binder in accordance with Larimer County Urban Area Street Standard (LCUASS).
Aggregate base should be consistent with CDOT requirements for Class 5 or Class 6 aggregate
base.
As previously mentioned, a final subgrade investigation and pavement design should be performed
in general accordance with LCUASS standards prior to placement of any pavement sections, to
determine the required pavement section after design configurations, roadway utilities have been
installed and roadway have been prepared to “rough” subgrade elevations have been completed.
Water Soluble Sulfates
The water-soluble sulfate (SO4) testing of the on-site overburden soils taken during our subsurface
exploration at varying depths are provided in the table below. Based on the reported sulfate content
test results, this report includes a recommendation for the CLASS of cement for use for contact in
association with the on-site subsoils.
Table IV: Water Soluble Sulfate Test Results
Sample Location Description Soluble Sulfate Content (%)
B-3 S-1 4' Lean Clay with Sand (CL) 0.3
B-9 S-1 4' Lean Clay with Sand (CL) 1.63
B-13 S-2 9' Lean Clay with Sand (CL) 0.18
Based on the results as presented in table above, ACI 318, Section 4.2 indicates the site overburden
soils have a severe risk of sulfate attack on Portland cement concrete. Therefore, ACI Class S2
requirements should be used for concrete on and below site grade within the overburden soils and
bedrock. Foundation concrete should be designed in accordance with the provisions of the ACI
Design Manual, Section 318, Chapter 5.
Utilities
Excavations into the on-site subsurface soils may encounter a variety of conditions. Shallow cuts
in the very near surface soils would be expected to stand on relatively steep temporary slopes;
however, cuts extending to greater depths could expose soft/loose unstable soils and groundwater.
Earth Engineering Consultants, LLC
EEC Project No. 1172058
April 22, 2024
Page 13
The wet and non-cohesive granular soils may be unstable in the trench excavations. Stabilization
of the sides and bottoms of some of the trenches and at least some dewatering should be anticipated
for deeper utilities. The individual contractor(s) should be made responsible for designing and
constructing stable, temporary excavations as required to maintain stability of both the
excavation’s sides and bottom. All excavations should be sloped or shored in the interest of safety
following local and federal regulations, including current OSHA excavation and trench safety
standards.
Other Considerations
Positive drainage should be developed away from the structures and pavement areas with a
minimum slope of 1 inch per foot for the first 10 feet away from the improvements in landscape
areas. Care should be taken in planning of landscaping adjacent to the buildings and parking and
drive areas to avoid features which would pond water adjacent to the pavement, foundations or
stem walls.
Placement of plants which require irrigation systems or could result in fluctuations of the moisture
content of the subgrade material should be avoided adjacent to site improvements. Lawn watering
systems should not be placed within 5 feet of the perimeter of the building and parking areas.
Spray heads should be designed not to spray water on or immediately adjacent to the structure or
site pavements. Roof drains should be designed to discharge at least 5 feet away from the structure
and away from the pavement areas.
GENERAL COMMENTS
The analysis and recommendations presented in this report are based upon the data obtained from
the soil borings performed at the indicated locations and from any other information discussed in
this report. This report does not reflect any variations which may occur between borings or across
the site. The nature and extent of such variations may not become evident until construction. If
variations appear evident, it will be necessary to re-evaluate the recommendations of this report.
It is recommended that the geotechnical engineer be retained to review the plans and specifications
so comments can be made regarding the interpretation and implementation of our geotechnical
recommendations in the design and specifications. It is further recommended that the geotechnical
Earth Engineering Consultants, LLC
EEC Project No. 1172058
April 22, 2024
Page 14
engineer be retained for testing and observations during earthwork and foundation construction
phases to help determine that the design requirements are fulfilled.
This report has been prepared for the exclusive use of Montava Development for the specific
application to the project discussed and has been prepared in accordance with generally accepted
geotechnical engineering practices. No warranty, express or implied, is made. In the event that
any changes in the nature, design or location of the project as outlined in this report are planned,
the conclusions and recommendations contained in this report shall not be considered valid unless
the changes are reviewed and the conclusions of this report are modified or verified in writing by
the geotechnical engineer.
Earth Engineering Consultants, LLC
DRILLING AND EXPLORATION
DRILLING & SAMPLING SYMBOLS:
SS: Split Spoon ‐ 13/8" I.D., 2" O.D., unless otherwise noted PS: Piston Sample
ST: Thin‐Walled Tube ‐ 2" O.D., unless otherwise noted WS: Wash Sample
R: Ring Barrel Sampler ‐ 2.42" I.D., 3" O.D. unless otherwise noted
PA: Power Auger FT: Fish Tail Bit
HA: Hand Auger RB: Rock Bit
DB: Diamond Bit = 4", N, B BS: Bulk Sample
AS: Auger Sample PM: Pressure Meter
HS: Hollow Stem Auger WB: Wash Bore
Standard "N" Penetration: Blows per foot of a 140 pound hammer falling 30 inches on a 2‐inch O.D. split spoon, except where noted.
WATER LEVEL MEASUREMENT SYMBOLS:
WL : Water Level WS : While Sampling
WCI: Wet Cave in WD : While Drilling
DCI: Dry Cave in BCR: Before Casing Removal
AB : After Boring ACR: After Casting Removal
Water levels indicated on the boring logs are the levels measured in the borings at the time indicated. In pervious soils, the indicated
levels may reflect the location of ground water. In low permeability soils, the accurate determination of ground water levels is not
possible with only short term observations.
DESCRIPTIVE SOIL CLASSIFICATION
Soil Classification is based on the Unified Soil Classification
system and the ASTM Designations D‐2488. Coarse Grained
Soils have move than 50% of their dry weight retained on a
#200 sieve; they are described as: boulders, cobbles, gravel or
sand. Fine Grained Soils have less than 50% of their dry weight
retained on a #200 sieve; they are described as : clays, if they
are plastic, and silts if they are slightly plastic or non‐plastic.
Major constituents may be added as modifiers and minor
constituents may be added according to the relative
proportions based on grain size. In addition to gradation,
coarse grained soils are defined on the basis of their relative in‐
place density and fine grained soils on the basis of their
consistency. Example: Lean clay with sand, trace gravel, stiff
(CL); silty sand, trace gravel, medium dense (SM).
CONSISTENCY OF FINE‐GRAINED SOILS
Unconfined Compressive
Strength, Qu, psf Consistency
< 500 Very Soft
500 ‐ 1,000 Soft
1,001 ‐ 2,000 Medium
2,001 ‐ 4,000 Stiff
4,001 ‐ 8,000 Very Stiff
8,001 ‐ 16,000 Very Hard
RELATIVE DENSITY OF COARSE‐GRAINED SOILS:
N‐Blows/ft Relative Density
0‐3 Very Loose
4‐9 Loose
10‐29 Medium Dense
30‐49 Dense
50‐80 Very Dense
80 + Extremely Dense
PHYSICAL PROPERTIES OF BEDROCK
DEGREE OF WEATHERING:
Slight Slight decomposition of parent material on
joints. May be color change.
Moderate Some decomposition and color change
throughout.
High Rock highly decomposed, may be extremely
broken.
HARDNESS AND DEGREE OF CEMENTATION:
Limestone and Dolomite:
Hard Difficult to scratch with knife.
Moderately Can be scratched easily with knife.
Hard Cannot be scratched with fingernail.
Soft Can be scratched with fingernail.
Shale, Siltstone and Claystone:
Hard Can be scratched easily with knife, cannot be
scratched with fingernail.
Moderately Can be scratched with fingernail.
Hard
Soft Can be easily dented but not molded with
fingers.
Sandstone and Conglomerate:
Well Capable of scratching a knife blade.
Cemented
Cemented Can be scratched with knife.
Poorly Can be broken apart easily with fingers.
Cemented
Group
Symbol
Group Name
Cu≥4 and 1<Cc≤3E GW Well-graded gravel F
Cu<4 and/or 1>Cc>3E GP Poorly-graded gravel F
Fines classify as ML or MH GM Silty gravel G,H
Fines Classify as CL or CH GC Clayey Gravel F,G,H
Cu≥6 and 1<Cc≤3E SW Well-graded sand I
Cu<6 and/or 1>Cc>3E SP Poorly-graded sand I
Fines classify as ML or MH SM Silty sand G,H,I
Fines classify as CL or CH SC Clayey sand G,H,I
inorganic PI>7 and plots on or above "A" Line CL Lean clay K,L,M
PI<4 or plots below "A" Line ML Silt K,L,M
organic Liquid Limit - oven dried Organic clay K,L,M,N
Liquid Limit - not dried Organic silt K,L,M,O
inorganic PI plots on or above "A" Line CH Fat clay K,L,M
PI plots below "A" Line MH Elastic Silt K,L,M
organic Liquid Limit - oven dried Organic clay K,L,M,P
Liquid Limit - not dried Organic silt K,L,M,O
Highly organic soils PT Peat
(D30)2
D10 x D60
GW-GM well graded gravel with silt NPI≥4 and plots on or above "A" line.
GW-GC well-graded gravel with clay OPI≤4 or plots below "A" line.
GP-GM poorly-graded gravel with silt PPI plots on or above "A" line.
GP-GC poorly-graded gravel with clay QPI plots below "A" line.
SW-SM well-graded sand with silt
SW-SC well-graded sand with clay
SP-SM poorly graded sand with silt
SP-SC poorly graded sand with clay
Earth Engineering Consultants, LLC
IIf soil contains >15% gravel, add "with gravel" to
group name
JIf Atterberg limits plots shaded area, soil is a CL-
ML, Silty clay
Unified Soil Classification System
Soil Classification
Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests
Sands 50% or more
coarse fraction
passes No. 4 sieve
Fine-Grained Soils
50% or more passes
the No. 200 sieve
<0.75 OL
Gravels with Fines
more than 12%
fines
Clean Sands Less
than 5% fines
Sands with Fines
more than 12%
fines
Clean Gravels Less
than 5% fines
Gravels more than
50% of coarse
fraction retained on
No. 4 sieve
Coarse - Grained Soils
more than 50%
retained on No. 200
sieve
CGravels with 5 to 12% fines required dual symbols:
Kif soil contains 15 to 29% plus No. 200, add "with sand"
or "with gravel", whichever is predominant.
<0.75 OH
Primarily organic matter, dark in color, and organic odor
ABased on the material passing the 3-in. (75-mm)
sieve
ECu=D60/D10 Cc=
HIf fines are organic, add "with organic fines" to
group name
LIf soil contains ≥ 30% plus No. 200 predominantly sand,
add "sandy" to group name.
MIf soil contains ≥30% plus No. 200 predominantly gravel,
add "gravelly" to group name.
DSands with 5 to 12% fines require dual symbols:
BIf field sample contained cobbles or boulders, or
both, add "with cobbles or boulders, or both" to
group name.FIf soil contains ≥15% sand, add "with sand" to
GIf fines classify as CL-ML, use dual symbol GC-
CM, or SC-SM.
Silts and Clays
Liquid Limit less
than 50
Silts and Clays
Liquid Limit 50 or
more
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100 110
PL
A
S
T
I
C
I
T
Y
I
N
D
E
X
(
P
I
)
LIQUID LIMIT (LL)
ML OR OL
MH OR OH
For Classification of fine-grained soils and
fine-grained fraction of coarse-grained
soils.
Equation of "A"-line
Horizontal at PI=4 to LL=25.5
then PI-0.73 (LL-20)
Equation of "U"-line
Vertical at LL=16 to PI-7,
then PI=0.9 (LL-8)
CL-ML
B-1
B-2
B-3
B-4
B-5
B-6
B-7
B-8
B-9
B-10
B-11
B-12
B-13
B-14
B-15
B-16
B-17
1
4
2
3
B-6
B-13
B-12
Approximate Boring
Locations
A SLAS LL
Legend
igre 1 Boring Location iagram
ontaa eelopment ract
ort ollins olorado
Proect 11720 ate April 202
1 Site Photos
Photos taen in approximate
location in direction of arro
Approx. Locations of
2017 Preliminary
Borings
B-1
B-2
B-3
B-4
B-5
B-6
B-7
B-8
B-9
B-10
B-11
B-12
B-13
B-14
B-15
B-16
B-17
B-6
B-13
1
4
2
3
B-12
A SLAS LL
igre 2 Boring Location iagram
ontaa eelopment ract
ort ollins olorado
Proect 11720 ate April 202
Approximate Boring
Locations
Legend
1 Site Photos
Photos taen in approximate
location in direction of arro
Approx. Locations of
2017 Preliminary
Borings
MONTAVA RACT
FORT COLLINS, COLORADO
EEC PROJECT NO. 1172058
APRIL 2024
MONTAVA RACT
FORT COLLINS, COLORADO
EEC PROJECT NO. 1172058
APRIL 2024
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
VEGETATION AND TOPSOIL _ _
1
LEAN CLAY WITH SAND (CL)_ _
gray/brown/rust, moist 2
very soft/compressible to medium stiff _ _
3
_ _
4
_ _
CS 5 WOH 1500 40.6 81.1 44 26 80.9
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 7 1500 24.1
_ _
11
_ _
12
_ _
13
_ _
14
_ _
CS 15 9 26.2 102.2
_ _
16
_ _
17
_ _
SAND WITH SILT AND GRAVEL (SW-SM)18
tan, gray, moist, medium dense _ _
loose 19
_ _
SS 20 9 12.7 7.5
_ _
21
_ _
22
_ _
23
_ _
24
*wet cave-in _ _
CS 25 21.8
BOTTOM OF BORING DEPTH 25'_ _
Earth Engineering Consultants, LLC
WOH - Denotes: Weight of Hammer, soft compressible zone at groundwater level
A-LIMITS SWELL
SURFACE ELEV 4997'4/22/2024 4' 9"
FINISH DATE 4/4/2024 4/9/2024 5'
SHEET 1 OF 1 WATER DEPTH
START DATE 4/4/2024 WHILE DRILLING 4'
MONTAVA DEVELOPMENT - TRACT D
LOG OF BORING B-1PROJECT NO: 1172058 APRIL 2024
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
VEGETATION AND TOPSOIL _ _
1
LEAN CLAY WITH SAND (CL)_ _
gray/rust, moist 2
very soft to medium stiff _ _
CS 3 2 1500 35.3 87.5 <500 psf None
_ _
4
_ _
SS 5 4 1500 25.5
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 8 21.4 106.9 8.5
WELL GRADED SAND WITH SILT (SW-SM)_ _
red/brown 11
loose _ _
12
_ _
13
_ _
14
_ _
SS 15 9 14.9
_ _
BOTTOM OF BORING DEPTH 15.5'16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-2 APRIL 2024
FORT COLLINS, COLORADO
SHEET 1 OF 1 WATER DEPTH
START DATE 4/5/2024 WHILE DRILLING 2.5'
SURFACE ELEV 4995'
FINISH DATE 4/5/2024
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
_ _
1
LEAN CLAY WITH SAND (CL)_ _
brown/gray/rust, moist 2
medium stiff _ _
3
_ _
4
_ _Water Soluble Sulfate Content = 0.3%
CS 5 5 2500 19.8 105.9 <500 psf None
_ _
6
_ _
7
_ _
SILTY / CLAYEY SAND (SM/SC))8
brown/rust _ _
very loose 9
_ _
SS 10 2 31.4
_ _
11
_ _
12
_ _
SAND / GRAVEL (SP / GP)13
tan, gray _ _
medium dense 14
_ _
CS 15 19 9.1 116.4
_ _
16
_ _
17
_ _
18
_ _
19
_ _
*wet cave-in SS 20 11.9
_ _
21
_ _
22
_ _
23
_ _
24
_ _
*wet cave-in CS 25 6.5
BOTTOM OF BORING DEPTH 25'_ _
Earth Engineering Consultants, LLC
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-3 APRIL 2024
FORT COLLINS, COLORADO
SHEET 1 OF 1 WATER DEPTH
START DATE 4/5/2024 WHILE DRILLING 6'
SURFACE ELEV 4998'
FINISH DATE 4/5/2024 AFTER DRILLING 4' 8"
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
_ _
1
LEAN CLAY WITH SAND (CL)_ _
gray/rust, moist 2
medium stiff to stiff _ _
3
_ _
4
_ _
CS 5 4 2500 28.6 93.9 <500 psf None
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 4 2000 22.2
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SAND / GRAVEL (SP / GP)CS 15 10 19.3 105.8
BOTTOM OF BORING DEPTH 15'_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV 4997'
FINISH DATE 4/5/2024
SHEET 1 OF 1 WATER DEPTH
START DATE 4/5/2024 WHILE DRILLING 8'
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-4 APRIL 2024
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
VEGETATION AND TOPSOIL _ _
1
LEAN CLAY WITH SAND (CL)_ _
gray/rust, moist 2
stiff _ _
3
_ _
4
_ _
CS 5 10 2000 26.9 99.2 42 29 77.4 <500 psf None
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 10 2500 18.4
_ _
11
_ _
12
_ _
13
_ _
14
_ _
CS 15 15 2500 24.0 101.3
_ _
16
_ _
SAND / GRAVEL (SP / GP)17
tan, gray _ _
dense 18
_ _
19
_ _
SS 20 35 8.0
_ _
21
_ _
22
_ _
23
_ _
24
_ _
clay zone SS 25 9 500 33.6
BOTTOM OF BORING DEPTH 25.5'_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV 4995'4/22/2024 4' 9"
FINISH DATE 4/2/2024 4/9/2024 4' 10"
SHEET 1 OF 1 WATER DEPTH
START DATE 4/2/2024 WHILE DRILLING 7'
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-5 APRIL 2024
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
_ _
1
LEAN CLAY (CL)_ _
gray, moist 2
very soft to stiff _ _
with gypsum crystals CS 3 4 2000 41.0 76.2 49 10 87.5 <500 psf None
_ _
4
_ _
SS 5 2 1500 28.5
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 10 2500 22.8 105.1
_ _
11
_ _
12
_ _
13
_ _
14
SAND / GRAVEL (SP / GP)_ _
tan, gray SS 15 5 21.2
dense _ _
BOTTOM OF BORING DEPTH 15.5'16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV 4998'
FINISH DATE 4/5/2024 AFTER DRILLING 5'
SHEET 1 OF 1 WATER DEPTH
START DATE 4/5/2024 WHILE DRILLING 4'
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-6 APRIL 2024
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
_ _
1
LEAN CLAY WITH SAND (CL)_ _
brown, moist 2
medium stiff _ _
with gypsum crystals CS 3 7 4000 22.9 <500 psf None
_ _
4
_ _
SS 5 7 3500 20.0
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 4 3000 24.8 103.1
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 9 3500 23.0
_ _
16
SILTY SAND (SM)_ _
tan, gray 17
medium dense _ _
18
_ _
19
_ _
CS 20 18 12.7 119.7
_ _
21
_ _
22
_ _
23
_ _
24
_ _
*wet cave-in SS 25 17.5
BOTTOM OF BORING DEPTH 25.5'_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV 4996'
FINISH DATE 4/5/2024
SHEET 1 OF 1 WATER DEPTH
START DATE 4/5/2024 WHILE DRILLING 7'
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-7 APRIL 2024
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
VEGETATION AND TOPSOIL _ _
1
SANDY LEAN CLAY (CL)_ _
brown/gray/rust, moist 2
medium stiff to stiff _ _
CS 3 9 2500 24.7 101.7 44 32 75.3 <500 psf None
_ _
4
_ _
SS 5 5 25.3
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 9 4000 28.1 98.8
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 13 18.0
SAND / SILTY SAND (SP / SM)_ _
tan, gray 16
medium dense to dense _ _
17
_ _
18
_ _
19
_ _
CS 20 30 10.6 119.1
BOTTOM OF BORING DEPTH 20'_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV 4995'
FINISH DATE 4/2/2024
SHEET 1 OF 1 WATER DEPTH
START DATE 4/2/2024 WHILE DRILLING 6'
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-8 APRIL 2024
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
_ _
1
LEAN CLAY WITH SAND (CL)_ _
gray/rust, moist 2
moist, stiff to medium stiff _ _
3
_ _
4
_ _Water Soluble Sulfate Content = 1.63%
CS 5 14 3500 27.2 98.7 <500 psf None
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 11 2000 20.8
_ _
11
_ _
WELL GRADED SAND WITH GRAVEL (SW)12
tan, gray _ _
medium dense 13
_ _
14
_ _
CS 15 15 13.9 124.8 4.1
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SS 20 24 6.7
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 10 10.1
BOTTOM OF BORING DEPTH 25'_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV 4997'4/22/2024 6'
FINISH DATE 4/2/2024 4/9/2024 6' 1"
SHEET 1 OF 1 WATER DEPTH
START DATE 4/2/2024 WHILE DRILLING 9'
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-9 APRIL 2024
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
VEGETATION AND TOPSOIL _ _
1
LEAN CLAY WITH SAND (CL)_ _
gray/rust, moist 2
stiff _ _
3
_ _
4
_ _
CS 5 13 4000 29.0 98.0 40 25 83.4 <500 psf None
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SILTY SAND (SM)SS 10 15 25.2 42.7
tan, gray _ _
medium dense 11
_ _
12
_ _
13
_ _
14
_ _
CS 15 16
BOTTOM OF BORING DEPTH 15'_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV 4996'
FINISH DATE 4/2/2024 4/9/2024 6'
SHEET 1 OF 1 WATER DEPTH
START DATE 4/2/2024 WHILE DRILLING 5.5'
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-10 APRIL 2024
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
VEGETATION AND TOPSOIL _ _
1
LEAN CLAY (CL)_ _
brown/gray, moist 2
stiff _ _ % @ 150 psf
CS 3 10 6500 37.9 81.9 43 8 85.3 <150 psf None
_ _
4
_ _
SS 5 8 3500 19.2
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 13 4000 20.0 109.4 <500 psf None
_ _
11
_ _
12
_ _
SAND (SP)13
tan, gray _ _
medium dense 14
_ _
SS 15 18 9.6
_ _
BOTTOM OF BORING DEPTH 15.5'16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV 4998'
FINISH DATE 4/2/2024
SHEET 1 OF 1 WATER DEPTH
START DATE 4/2/2024 WHILE DRILLING 8'
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-11 APRIL 2024
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
_ _
1
LEAN CLAY WITH SAND (CL)_ _
brown/gray, moist 2
very stiff to stiff _ _ % @ 150 psf
CS 3 17 5000 28.5 89.0 <150 psf None
_ _
4
_ _
CS 5 10 3500 28.1
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 9 3000 27.9 96.7
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SAND / GRAVEL (SP / GP)CS 15 14 2500 24.3
BOTTOM OF BORING DEPTH 15'_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV 4995'4/22/2024 6' 8-1/2"
FINISH DATE 4/2/2024 4/9/2024 6' 9"
SHEET 1 OF 1 WATER DEPTH
START DATE 4/2/2024 WHILE DRILLING 7'
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-12 APRIL 2024
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
_ _
1
LEAN CLAY WITH SAND (CL)_ _
gray/rust, moist 2
stiff to very stiff _ _
3
_ _
4
_ _
CS 5 14 4000 16.8 107.8 28 15 72.7 <500 psf None
_ _
6
_ _
7
_ _
8
_ _
9
_ _Water Soluble Sulfate Content = 0.18%
SS 10 12 2500 20.6
_ _
11
_ _
12
_ _
13
_ _
14
_ _
CS 15 18 5000 25.8 105.0
BOTTOM OF BORING DEPTH 15'_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV 4995'
FINISH DATE 4/2/2024
SHEET 1 OF 1 WATER DEPTH
START DATE 4/2/2024 WHILE DRILLING 8.5'
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-13 APRIL 2024
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
_ _
1
LEAN CLAY WITH SAND (CL)_ _
brown/tan/rust 2
moist, medium stiff _ _
3
_ _
4
_ _
CS 5 10 3500 23.3 101.8 <500 psf None
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 7 2500 22.2
_ _
11
_ _
12
_ _
SAND WITH SILT AND GRAVEL (SW-SM)13
tan, gray, moist _ _
medium dense 14
_ _
CS 15 10 11.3 110.1 6.2
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SS 20 15 13.6
_ _
21
_ _
22
_ _
23
_ _
24
_ _
*wet cave-in CS 25 14.3
BOTTOM OF BORING DEPTH 25'_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV 4997'
FINISH DATE 4/5/2024
SHEET 1 OF 1 WATER DEPTH
START DATE 4/5/2024 WHILE DRILLING 9.5'
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-14 APRIL 2024
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
VEGETATION AND TOPSOIL _ _
1
LEAN CLAY WITH SAND (CL)_ _
brown, moist 2
very stiff to stiff _ _
with gypsum crystals 3
_ _
4
_ _
CS 5 22 7000 21.3 106.3 <500 psf None
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 14 5000 19.3 106.8
_ _
11
_ _
12
_ _
13
_ _
14
_ _
CS 15 25 6000 19.1
_ _
16
SAND / GRAVEL (SP / GP)_ _
tan, gay 17
medium dense to dense _ _
18
_ _
19
_ _
SS 20 14 11.7 101.6
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 39 6.4
BOTTOM OF BORING DEPTH 25'_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV 4999'4/22/2024 10 11"
FINISH DATE 4/2/2024 4/9/2024 11'
SHEET 1 OF 1 WATER DEPTH
START DATE 4/2/2024 WHILE DRILLING 10'
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-15 APRIL 2024
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
SPARSE VEGETATION _ _
1
LEAN CLAY WITH SAND (CL)_ _
tan/gray, moist 2
medium stiff to stiff _ _% @ 150 psf
CS 3 15 1500 45.6 77.1 <150 psf None
_ _
4
_ _
SS 5 9 2000 26.5
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 9 5000 20.9 105.1
_ _
11
_ _
12
_ _
13
_ _
SAND / GRAVEL (SP / GP)14
tan, gray _ _
medium dense to dense SS 15 20 11.3
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 11 500 12.3 119.9
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 45 7.9
BOTTOM OF BORING DEPTH 25.5'_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV 4994'4/22/2024 6' 7-3/4"
FINISH DATE 4/2/2024 4/9/2024 6' 7"
SHEET 1 OF 1 WATER DEPTH
START DATE 4/2/2024 WHILE DRILLING 8.5'
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-16 APRIL 2024
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
_ _
1
LEAN CLAY WITH SAND (CL)_ _
brown, moist 2
stiff to medium stiff _ _% @ 150 psf
with calcareous deposits and gypsum crystals CS 3 9 3500 24.8 99.5 200 psf 0.3%
_ _
4
_ _
SS 5 8 3500 21.8
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 6 2500 22.9 101.5 <500 psf None
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 9 4000 21.9
_ _
BOTTOM OF BORING DEPTH 15.5'16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV 4999'
FINISH DATE 4/5/2024
SHEET 1 OF 1 WATER DEPTH
START DATE 4/5/2024 WHILE DRILLING None
MONTAVA DEVELOPMENT - TRACT D
PROJECT NO: 1172058 LOG OF BORING B-17 APRIL 2024
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(BLOWS/FT)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
_ _
1
_ _
SANDY LEAN CLAY (CL)2
gray / rust _ _
soft to medium stiff 3
_ _
4
_ _
CS 5 4 1500 21.3 103.2 34 20 58.2 <500 psf none
_ _
6
_ _
7
_ _
8
_ _
9
brown / rust / gray _ _
SS 10 14 1000 27.1
_ _
SILTY SAND / GRAVEL (SM / GM)11
brown / rust / gray _ _
loose 12
_ _
13
_ _
14
_ _
CS 15 5
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SS 20 8 --10.6
_ _
21
_ _
22
_ _
23
_ _
24
SANDSTONE / SILTSTONE / CLAYSTONE _ _
gray / brown / rust CS 25 37 3500 17.8
BOTTOM OF BORING DEPTH 25.0'_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/18/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/18/2017 WHILE DRILLING 4.5'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-6 SEPTEMBER 2017
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(BLOWS/FT)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
_ _
1
_ _
SANDY LEAN CLAY (CL)2
brown _ _
very stiff CS 3 8 6500 16.5 98.6
with calcareous deposits _ _
4
_ _
SS 5 9 6000 15.3
_ _
6
_ _
7
_ _
8
_ _
9
brown / tan _ _
CS 10 4 6000 20.7 100.2
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 9 6000 18.1
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SAND / GRAVEL (SP / GP)CS 20 20 --10.1 132.6
brown / tan _ _
medium dense 21
with cobbles and clay seams _ _
22
_ _
23
_ _
24
_ _
SS 25 10 --7.9
BOTTOM OF BORING DEPTH 25.5'_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV N/A CHECKED ON 8/28/2017 15.0'
FINISH DATE 8/14/2017 CHECKED ON 9/8/2017 16.5'
SHEET 1 OF 1 WATER DEPTH
START DATE 8/14/2017 WHILE DRILLING 14.5'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-12 SEPTEMBER 2017
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET)(BLOWS/FT)(PSF)(%)(PCF)LL PI (%)PRESSURE % @ 500 PSF
VEGETATION & TOPSOIL _ _
1
_ _
CLAYEY SAND (SC)2
gray _ _
loose to very loose CS 3 8 4000 24.8 86.5
_ _
4
_ _
SS 5 2 1000 36.2
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SILTY SAND (SM)CS 10 6 --21.6 104.2 NL NP 30.3 <500 psf none
brown / rust / gray _ _
loose to medium dense 11
_ _
12
_ _
13
_ _
14
_ _
SS 15 12 1500 22.9
_ _
16
_ _
SAND / GRAVEL (SP / GP)17
rust / brown _ _
medium dense 18
_ _
19
_ _
CS 20 22 1000 8.0 130.3
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 10 --9.2
BOTTOM OF BORING DEPTH 25.5'_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/14/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/14/2017 WHILE DRILLING 10.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-13 SEPTEMBER 2017
Project:
Location:
Project #:
Date:
Beginning Moisture: 35.3%Dry Density: 87.6 pcf Ending Moisture: 26.6%
Material Description:Lean Clay with Sand
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Beginning Moisture: 19.8%Dry Density: 104.8 pcf Ending Moisture: 19.6%
Material Description:Lean Clay with Sand
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Material Description:Lean Clay with Sand
Beginning Moisture: 28.6%Dry Density: 92.4 pcf Ending Moisture: 25.6%
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Beginning Moisture: 26.9%Dry Density: 98.2 pcf Ending Moisture: 20.2%
Material Description:Lean Clay with Sand
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Beginning Moisture: 41.0%Dry Density: 79.7 pcf Ending Moisture: 29.3%
Material Description:Lean Clay
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Material Description:Lean Clay with Sand
Beginning Moisture: 24.8%Dry Density: 100 pcf Ending Moisture: 18.6%
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Beginning Moisture: 28.1%Dry Density: 95.7 pcf Ending Moisture: 21.1%
Material Description:Lean Clay with Sand
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Material Description:Lean Clay with Sand
Beginning Moisture: 27.2%Dry Density: 95.7 pcf Ending Moisture: 24.6%
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Beginning Moisture: 29.0%Dry Density: 93.7 pcf Ending Moisture: 22.6%
Material Description:Lean Clay with Sand
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Beginning Moisture: 37.9%Dry Density: 81.1 pcf Ending Moisture: 42.1%
Material Description: Lean Clay
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Material Description:Lean Clay with Sand
Beginning Moisture: 20.0%Dry Density: 106.3 pcf Ending Moisture: 33.8%
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Material Description:Lean Clay with Sand
Beginning Moisture: 28.5%Dry Density: 89.5 pcf Ending Moisture: 18.4%
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Beginning Moisture: 16.8%Dry Density: 106.4 pcf Ending Moisture: 19.4%
Material Description:Lean Clay with Sand
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Material Description:Lean Clay with Sand
Beginning Moisture: 23.3%Dry Density: 98.5 pcf Ending Moisture: 17.3%
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Material Description:Lean Clay with Sand
Beginning Moisture: 21.3%Dry Density: 101.8 pcf Ending Moisture: 21.7%
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Material Description:Lean Clay with Sand
Beginning Moisture: 45.6%Dry Density: 76.2 pcf Ending Moisture: 45.1%
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Material Description:Lean Clay with Sand
Beginning Moisture: 24.8%Dry Density: 98 pcf Ending Moisture: 25.1%
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
Project:
Location:
Project #:
Date:
Material Description:Lean Clay with Sand
Beginning Moisture: 22.9%Dry Density: 100.4 pcf Ending Moisture: 21.9%
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Pe
r
c
e
n
t
M
o
v
e
m
e
n
t
Load (TSF)
Sw
e
l
l
Co
n
s
o
l
i
d
a
t
i
o
n
2 1/2"(63 mm)
2"(50 mm)
1 1/2"(37.5 mm)
1"(25 mm)
3/4"(19 mm)
1/2"(12.5 mm)
3/8"(9.5 mm)
No. 4 (4.75 mm)
No. 8 (2.36 mm)
No. 10 (2 mm)
No. 16 (1.18 mm)
No. 30 (0.6 mm)
No. 40 (0.425 mm)
No. 50 (0.3 mm)
No. 100 (0.15 mm)
No. 200 (0.075 mm)
Project:Montava Development - Tract D
Location:Fort Collins, Colorado
Project No:1172058
Sample ID:B1 S4 19
Sample Desc.:Well Graded Sand with Silt and Gravel (SW-SM
Date:April 2024
EARTH ENGINEERING CONSULTANTS, LLC
SUMMARY OF LABORATORY TEST RESULTS
Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136)
100
Sieve Size Percent Passing
100
100
100
100
97
93
73
54
13
7.5
51
41
28
23
19
0.68 0.11
Fine
27.70 1.35
D30 D10 Cu CC
April 2024
19.00 3.08 1.91
D100 D60 D50
EARTH ENGINEERING CONSULTANTS, LLC
Summary of Washed Sieve Analysis Tests (ASTM C117 & C136)
Date:
Project:
Location:
Project No:
Sample ID:
Sample Desc.:
Cobble Silt or ClayGravel
Coarse Fine
Sand
Coarse Medium
6"
5"
4"
3"
2.5"
2"
1.5"
1"
3/4"
1/2"
3/8"
No. 4
No. 8
No. 10
No. 16
No. 30
No. 40
No. 50
No. 100
No. 200
0
10
20
30
40
50
60
70
80
90
100
0.010.11101001000
Fi
n
e
r
b
y
W
e
i
g
h
t
(
%
)
Grain Size (mm)
Standard Sieve Size
2 1/2"(63 mm)
2"(50 mm)
1 1/2"(37.5 mm)
1"(25 mm)
3/4"(19 mm)
1/2"(12.5 mm)
3/8"(9.5 mm)
No. 4 (4.75 mm)
No. 8 (2.36 mm)
No. 10 (2 mm)
No. 16 (1.18 mm)
No. 30 (0.6 mm)
No. 40 (0.425 mm)
No. 50 (0.3 mm)
No. 100 (0.15 mm)
No. 200 (0.075 mm)
Project:Montava Development - Tract D
Location:Fort Collins, Colorado
Project No:1172058
Sample ID:B2 S3 9
Sample Desc.:Well Graded Sand with Silt (SW-SM)
Date:April 2024
EARTH ENGINEERING CONSULTANTS, LLC
SUMMARY OF LABORATORY TEST RESULTS
Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136)
100
Sieve Size Percent Passing
100
100
100
100
99
99
94
88
20
8.5
87
81
77
74
58
0.19 0.08
Fine
3.76 1.35
D30 D10 Cu CC
April 2024
19.00 0.32 0.27
D100 D60 D50
EARTH ENGINEERING CONSULTANTS, LLC
Summary of Washed Sieve Analysis Tests (ASTM C117 & C136)
Date:
Project:
Location:
Project No:
Sample ID:
Sample Desc.:
Cobble Silt or ClayGravel
Coarse Fine
Sand
Coarse Medium
6"
5"
4"
3"
2.5"
2"
1.5"
1"
3/4"
1/2"
3/8"
No. 4
No. 8
No. 10
No. 16
No. 30
No. 40
No. 50
No. 100
No. 200
0
10
20
30
40
50
60
70
80
90
100
0.010.11101001000
Fi
n
e
r
b
y
W
e
i
g
h
t
(
%
)
Grain Size (mm)
Standard Sieve Size
2 1/2"(63 mm)
2"(50 mm)
1 1/2"(37.5 mm)
1"(25 mm)
3/4"(19 mm)
1/2"(12.5 mm)
3/8"(9.5 mm)
No. 4 (4.75 mm)
No. 8 (2.36 mm)
No. 10 (2 mm)
No. 16 (1.18 mm)
No. 30 (0.6 mm)
No. 40 (0.425 mm)
No. 50 (0.3 mm)
No. 100 (0.15 mm)
No. 200 (0.075 mm)
Project:Montava Development - Tract D
Location:Fort Collins, Colorado
Project No:1172058
Sample ID:B9 S3 14
Sample Desc.:Well Graded Sand with Gravel (SW)
Date:April 2024
EARTH ENGINEERING CONSULTANTS, LLC
SUMMARY OF LABORATORY TEST RESULTS
Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136)
100
Sieve Size Percent Passing
100
100
100
100
98
93
74
56
7
4.1
52
40
24
18
13
0.81 0.23
Fine
12.68 0.99
D30 D10 Cu CC
April 2024
19.00 2.89 1.84
D100 D60 D50
EARTH ENGINEERING CONSULTANTS, LLC
Summary of Washed Sieve Analysis Tests (ASTM C117 & C136)
Date:
Project:
Location:
Project No:
Sample ID:
Sample Desc.:
Cobble Silt or ClayGravel
Coarse Fine
Sand
Coarse Medium
6"
5"
4"
3"
2.5"
2"
1.5"
1"
3/4"
1/2"
3/8"
No. 4
No. 8
No. 10
No. 16
No. 30
No. 40
No. 50
No. 100
No. 200
0
10
20
30
40
50
60
70
80
90
100
0.010.11101001000
Fi
n
e
r
b
y
W
e
i
g
h
t
(
%
)
Grain Size (mm)
Standard Sieve Size
2 1/2"(63 mm)
2"(50 mm)
1 1/2"(37.5 mm)
1"(25 mm)
3/4"(19 mm)
1/2"(12.5 mm)
3/8"(9.5 mm)
No. 4 (4.75 mm)
No. 8 (2.36 mm)
No. 10 (2 mm)
No. 16 (1.18 mm)
No. 30 (0.6 mm)
No. 40 (0.425 mm)
No. 50 (0.3 mm)
No. 100 (0.15 mm)
No. 200 (0.075 mm)
Project:Montava Development - Tract D
Location:Fort Collins, Colorado
Project No:1172058
Sample ID:B10 S2 9
Sample Desc.:Silty Sand (SM)
Date:April 2024
EARTH ENGINEERING CONSULTANTS, LLC
SUMMARY OF LABORATORY TEST RESULTS
Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136)
100
Sieve Size Percent Passing
100
100
100
100
100
98
94
88
64
42.7
86
83
79
77
74
------
Fine
------
D30 D10 Cu CC
April 2024
12.50 0.14 0.10
D100 D60 D50
EARTH ENGINEERING CONSULTANTS, LLC
Summary of Washed Sieve Analysis Tests (ASTM C117 & C136)
Date:
Project:
Location:
Project No:
Sample ID:
Sample Desc.:
Cobble Silt or ClayGravel
Coarse Fine
Sand
Coarse Medium
6"
5"
4"
3"
2.5"
2"
1.5"
1"
3/4"
1/2"
3/8"
No. 4
No. 8
No. 10
No. 16
No. 30
No. 40
No. 50
No. 100
No. 200
0
10
20
30
40
50
60
70
80
90
100
0.010.11101001000
Fi
n
e
r
b
y
W
e
i
g
h
t
(
%
)
Grain Size (mm)
Standard Sieve Size
APPENDIX B
USDA SOIL SURVEY INFORMATION
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
Larimer County
Area, ColoradoNatural
Resources
Conservation
Service
July 9, 2024
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................................................................................................11
Map Unit Descriptions.........................................................................................11
Larimer County Area, Colorado......................................................................13
5—Aquepts, loamy......................................................................................13
22—Caruso clay loam, 0 to 1 percent slope...............................................14
35—Fort Collins loam, 0 to 3 percent slopes..............................................15
36—Fort Collins loam, 3 to 5 percent slopes..............................................16
95—Satanta loam, 1 to 3 percent slopes....................................................18
98—Satanta Variant clay loam, 0 to 3 percent slopes.................................19
101—Stoneham loam, 1 to 3 percent slopes..............................................20
Soil Information for All Uses...............................................................................23
Soil Properties and Qualities..............................................................................23
Soil Qualities and Features.............................................................................23
Hydrologic Soil Group.................................................................................23
References............................................................................................................28
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
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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
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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
44
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497500 497600 497700 497800 497900 498000 498100 498200 498300 498400
497500 497600 497700 497800 497900 498000 498100 498200 498300 498400
40° 37' 15'' N
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Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 300 600 1200 1800
Feet
0 50 100 200 300
Meters
Map Scale: 1:6,260 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: Larimer County Area, Colorado
Survey Area Data: Version 18, Aug 24, 2023
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Jul 2, 2021—Aug 25,
2021
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
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Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
5 Aquepts, loamy 0.4 0.4%
22 Caruso clay loam, 0 to 1
percent slope
0.1 0.1%
35 Fort Collins loam, 0 to 3 percent
slopes
34.3 31.2%
36 Fort Collins loam, 3 to 5 percent
slopes
4.4 4.0%
95 Satanta loam, 1 to 3 percent
slopes
2.1 1.9%
98 Satanta Variant clay loam, 0 to
3 percent slopes
67.7 61.5%
101 Stoneham loam, 1 to 3 percent
slopes
1.1 1.0%
Totals for Area of Interest 110.1 100.0%
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
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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.
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.
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Larimer County Area, Colorado
5—Aquepts, loamy
Map Unit Setting
National map unit symbol: jpws
Elevation: 4,500 to 6,700 feet
Mean annual precipitation: 12 to 18 inches
Mean annual air temperature: 39 to 50 degrees F
Frost-free period: 80 to 140 days
Farmland classification: Not prime farmland
Map Unit Composition
Aquepts and similar soils:80 percent
Minor components:20 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Aquepts
Setting
Landform:Depressions, draws, stream terraces
Landform position (three-dimensional):Base slope, tread, dip
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Loamy alluvium
Typical profile
H1 - 0 to 60 inches: variable
Properties and qualities
Slope:0 to 3 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Very poorly drained
Runoff class: Negligible
Capacity of the most limiting layer to transmit water (Ksat):Moderately high to very
high (0.60 to 99.90 in/hr)
Depth to water table:About 6 to 18 inches
Frequency of flooding:Rare
Frequency of ponding:None
Interpretive groups
Land capability classification (irrigated): 5w
Land capability classification (nonirrigated): 3w
Hydrologic Soil Group: A/D
Ecological site: R067BY038CO - Wet Meadow
Hydric soil rating: Yes
Minor Components
Nunn
Percent of map unit:5 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Kim
Percent of map unit:5 percent
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Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Stoneham
Percent of map unit:5 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Fort collins
Percent of map unit:5 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
22—Caruso clay loam, 0 to 1 percent slope
Map Unit Setting
National map unit symbol: jpvt
Elevation: 4,800 to 5,500 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Caruso and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Caruso
Setting
Landform:Flood-plain steps, stream terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Mixed alluvium
Typical profile
H1 - 0 to 35 inches: clay loam
H2 - 35 to 44 inches: fine sandy loam
H3 - 44 to 60 inches: gravelly sand
Properties and qualities
Slope:0 to 1 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Somewhat poorly 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:About 24 to 48 inches
Frequency of flooding:Occasional
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Frequency of ponding:None
Calcium carbonate, maximum content:5 percent
Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
Available water supply, 0 to 60 inches: Moderate (about 8.4 inches)
Interpretive groups
Land capability classification (irrigated): 3w
Land capability classification (nonirrigated): 5w
Hydrologic Soil Group: D
Ecological site: R067BY036CO - Overflow
Hydric soil rating: No
Minor Components
Loveland
Percent of map unit:9 percent
Landform:Terraces
Ecological site:R067BY036CO - Overflow
Hydric soil rating: Yes
Fluvaquents
Percent of map unit:6 percent
Landform:Terraces
Hydric soil rating: Yes
35—Fort Collins loam, 0 to 3 percent slopes
Map Unit Setting
National map unit symbol: 2tlnc
Elevation: 4,020 to 6,730 feet
Mean annual precipitation: 14 to 16 inches
Mean annual air temperature: 46 to 48 degrees F
Frost-free period: 135 to 160 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Fort collins and similar soils:85 percent
Minor components:15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Fort Collins
Setting
Landform:Interfluves, stream terraces
Landform position (three-dimensional):Interfluve, tread
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Pleistocene or older alluvium and/or eolian deposits
Typical profile
Ap - 0 to 4 inches: loam
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Bt1 - 4 to 9 inches: clay loam
Bt2 - 9 to 16 inches: clay loam
Bk1 - 16 to 29 inches: loam
Bk2 - 29 to 80 inches: loam
Properties and qualities
Slope:0 to 3 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
(0.20 to 2.00 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:12 percent
Maximum salinity:Nonsaline to very slightly saline (0.1 to 2.0 mmhos/cm)
Available water supply, 0 to 60 inches: High (about 9.1 inches)
Interpretive groups
Land capability classification (irrigated): 3e
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: C
Ecological site: R067BY002CO - Loamy Plains
Hydric soil rating: No
Minor Components
Nunn
Percent of map unit:10 percent
Landform:Stream terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Vona
Percent of map unit:5 percent
Landform:Interfluves
Landform position (three-dimensional):Interfluve, side slope
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY024CO - Sandy Plains
Hydric soil rating: No
36—Fort Collins loam, 3 to 5 percent slopes
Map Unit Setting
National map unit symbol: 2yqpg
Elevation: 4,800 to 5,900 feet
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Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Fort collins and similar soils:80 percent
Minor components:20 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Fort Collins
Setting
Landform:Alluvial fans, terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear, convex
Across-slope shape:Linear
Parent material:Pleistocene or older alluvium and/or eolian deposits
Typical profile
Ap - 0 to 5 inches: loam
Bt1 - 5 to 8 inches: clay loam
Bt2 - 8 to 18 inches: clay loam
Bk1 - 18 to 24 inches: loam
Bk2 - 24 to 80 inches: loam
Properties and qualities
Slope:3 to 5 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
(0.20 to 2.00 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:12 percent
Maximum salinity:Nonsaline to very slightly saline (0.1 to 2.0 mmhos/cm)
Available water supply, 0 to 60 inches: High (about 9.1 inches)
Interpretive groups
Land capability classification (irrigated): 4e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: C
Ecological site: R067BY002CO - Loamy Plains
Hydric soil rating: No
Minor Components
Table mountain
Percent of map unit:15 percent
Landform:Alluvial fans, stream terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY036CO - Overflow
Hydric soil rating: No
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Larim
Percent of map unit:5 percent
Landform:Alluvial fans
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY063CO - Gravel Breaks
Hydric soil rating: No
95—Satanta loam, 1 to 3 percent slopes
Map Unit Setting
National map unit symbol: 2w5f3
Elevation: 3,650 to 5,350 feet
Mean annual precipitation: 12 to 18 inches
Mean annual air temperature: 46 to 54 degrees F
Frost-free period: 115 to 155 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Satanta and similar soils:90 percent
Minor components:10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Satanta
Setting
Landform:Paleoterraces
Landform position (two-dimensional):Backslope
Landform position (three-dimensional):Head slope
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Eolian sands
Typical profile
Ap - 0 to 9 inches: loam
Bt - 9 to 18 inches: clay loam
C - 18 to 79 inches: loam
Properties and qualities
Slope:1 to 3 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 (0.20
to 0.60 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:10 percent
Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
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Available water supply, 0 to 60 inches: Very high (about 12.2 inches)
Interpretive groups
Land capability classification (irrigated): 3e
Land capability classification (nonirrigated): 4c
Hydrologic Soil Group: C
Ecological site: R067BY002CO - Loamy Plains
Hydric soil rating: No
Minor Components
Nunn
Percent of map unit:5 percent
Landform:Terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Fort collins
Percent of map unit:5 percent
Landform:Alluvial fans
Landform position (two-dimensional):Backslope
Landform position (three-dimensional):Head slope
Down-slope shape:Linear
Across-slope shape:Linear
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
98—Satanta Variant clay loam, 0 to 3 percent slopes
Map Unit Setting
National map unit symbol: jpyh
Elevation: 4,800 to 5,600 feet
Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Satanta variant and similar soils:90 percent
Minor components:10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Satanta Variant
Setting
Landform:Terraces
Landform position (three-dimensional):Tread
Down-slope shape:Linear
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Across-slope shape:Linear
Parent material:Alluvium
Typical profile
H1 - 0 to 9 inches: clay loam
H2 - 9 to 22 inches: clay loam
H3 - 22 to 60 inches: loam
Properties and qualities
Slope:0 to 3 percent
Depth to restrictive feature:More than 80 inches
Drainage class:Somewhat poorly 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:About 24 to 48 inches
Frequency of flooding:Occasional
Frequency of ponding:None
Calcium carbonate, maximum content:15 percent
Gypsum, maximum content:10 percent
Maximum salinity:Very slightly saline to slightly saline (2.0 to 4.0 mmhos/cm)
Available water supply, 0 to 60 inches: Moderate (about 8.7 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: D
Ecological site: R067BY036CO - Overflow
Hydric soil rating: No
Minor Components
Nunn
Percent of map unit:5 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Caruso
Percent of map unit:3 percent
Ecological site:R067BY036CO - Overflow
Hydric soil rating: No
Loveland
Percent of map unit:2 percent
Ecological site:R067BY036CO - Overflow
Hydric soil rating: No
101—Stoneham loam, 1 to 3 percent slopes
Map Unit Setting
National map unit symbol: jptt
Elevation: 4,800 to 5,600 feet
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Mean annual precipitation: 13 to 15 inches
Mean annual air temperature: 48 to 50 degrees F
Frost-free period: 135 to 150 days
Farmland classification: Prime farmland if irrigated
Map Unit Composition
Stoneham and similar soils:90 percent
Minor components:10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Stoneham
Setting
Landform:Benches, terraces
Landform position (three-dimensional):Base slope, tread
Down-slope shape:Linear
Across-slope shape:Linear
Parent material:Mixed alluvium and/or eolian deposits
Typical profile
H1 - 0 to 4 inches: loam
H2 - 4 to 10 inches: sandy clay loam
H3 - 10 to 60 inches: clay loam
Properties and qualities
Slope:1 to 3 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 2.00 in/hr)
Depth to water table:More than 80 inches
Frequency of flooding:None
Frequency of ponding:None
Calcium carbonate, maximum content:15 percent
Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)
Available water supply, 0 to 60 inches: High (about 9.6 inches)
Interpretive groups
Land capability classification (irrigated): 2e
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: B
Ecological site: R067BY002CO - Loamy Plains
Hydric soil rating: No
Minor Components
Fort collins
Percent of map unit:5 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
Kim
Percent of map unit:5 percent
Ecological site:R067BY002CO - Loamy Plains
Hydric soil rating: No
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Soil Information for All Uses
Soil Properties and Qualities
The Soil Properties and Qualities section includes various soil properties and
qualities displayed as thematic maps with a summary table for the soil map units in
the selected area of interest. A single value or rating for each map unit is generated
by aggregating the interpretive ratings of individual map unit components. This
aggregation process is defined for each property or quality.
Soil Qualities and Features
Soil qualities are behavior and performance attributes that are not directly
measured, but are inferred from observations of dynamic conditions and from soil
properties. Example soil qualities include natural drainage, and frost action. Soil
features are attributes that are not directly part of the soil. Example soil features
include slope and depth to restrictive layer. These features can greatly impact the
use and management of the soil.
Hydrologic Soil Group
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive precipitation
from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly
wet. These consist mainly of deep, well drained to excessively drained sands or
gravelly sands. These soils have a high rate of water transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well drained
soils that have moderately fine texture to moderately coarse texture. These soils
have a moderate rate of water transmission.
23
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of water
transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay layer at
or near the surface, and soils that are shallow over nearly impervious material.
These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in their
natural condition are in group D are assigned to dual classes.
Custom Soil Resource Report
24
25
Custom Soil Resource Report
Map—Hydrologic Soil Group
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497500 497600 497700 497800 497900 498000 498100 498200 498300 498400
497500 497600 497700 497800 497900 498000 498100 498200 498300 498400
40° 37' 15'' N
10
5
°
1
'
4
8
'
'
W
40° 37' 15'' N
10
5
°
1
'
7
'
'
W
40° 36' 33'' N
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5
°
1
'
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8
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'
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40° 36' 33'' N
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5
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7
'
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N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 300 600 1200 1800
Feet
0 50 100 200 300
Meters
Map Scale: 1:6,260 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 Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
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: Larimer County Area, Colorado
Survey Area Data: Version 18, Aug 24, 2023
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Jul 2, 2021—Aug 25,
2021
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Custom Soil Resource Report
26
Table—Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
5 Aquepts, loamy A/D 0.4 0.4%
22 Caruso clay loam, 0 to 1
percent slope
D 0.1 0.1%
35 Fort Collins loam, 0 to 3
percent slopes
C 34.3 31.2%
36 Fort Collins loam, 3 to 5
percent slopes
C 4.4 4.0%
95 Satanta loam, 1 to 3
percent slopes
C 2.1 1.9%
98 Satanta Variant clay
loam, 0 to 3 percent
slopes
D 67.7 61.5%
101 Stoneham loam, 1 to 3
percent slopes
B 1.1 1.0%
Totals for Area of Interest 110.1 100.0%
Rating Options—Hydrologic Soil Group
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Custom Soil Resource Report
27
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
28
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
29
APPENDIX C
URBAN DRAINAGE AND FLOOD CONTROL DISTRICT BMPs
Surface Roughening (SR) EC-1
November 2010 Urban Drainage and Flood Control District SR-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph SR-1. Surface roughening via imprinting for temporary
stabilization.
Description
Surface roughening is an erosion control
practice that involves tracking,
scarifying, imprinting, or tilling a
disturbed area to provide temporary
stabilization of disturbed areas. Surface
roughening creates variations in the soil
surface that help to minimize wind and
water erosion. Depending on the
technique used, surface roughening may
also help establish conditions favorable
to establishment of vegetation.
Appropriate Uses
Surface roughening can be used to
provide temporary stabilization of
disturbed areas, such as when
revegetation cannot be immediately established due to seasonal planting limitations. Surface roughening
is not a stand-alone BMP, and should be used in conjunction with other erosion and sediment controls.
Surface roughening is often implemented in conjunction with grading and is typically performed using
heavy construction equipment to track the surface. Be aware that tracking with heavy equipment will also
compact soils, which is not desirable in areas that will be revegetated. Scarifying, tilling, or ripping are
better surface roughening techniques in locations where revegetation is planned. Roughening is not
effective in very sandy soils and cannot be effectively performed in rocky soil.
Design and Installation
Typical design details for surfacing roughening on steep and mild slopes are provided in Details SR-1 and
SR-2, respectively.
Surface roughening should be performed either after final grading or to temporarily stabilize an area
during active construction that may be inactive for a short time period. Surface roughening should create
depressions 2 to 6 inches deep and approximately 6 inches apart. The surface of exposed soil can be
roughened by a number of techniques and equipment. Horizontal grooves (running parallel to the
contours of the land) can be made using tracks from equipment treads, stair-step grading, ripping, or
tilling.
Fill slopes can be constructed with a roughened surface. Cut slopes that have been smooth graded can be
roughened as a subsequent operation. Roughening should follow along the contours of the slope. The
tracks left by truck mounted equipment working perpendicular
to the contour can leave acceptable horizontal depressions;
however, the equipment will also compact the soil.
Surface Roughening
Functions
Erosion Control Yes
Sediment Control No
Site/Material Management No
EC-1 Surface Roughening (SR)
SR-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Maintenance and Removal
Care should be taken not to drive vehicles or equipment over areas that have been surface roughened.
Tire tracks will smooth the roughened surface and may cause runoff to collect into rills and gullies.
Because surface roughening is only a temporary control, additional treatments may be necessary to
maintain the soil surface in a roughened condition.
Areas should be inspected for signs of erosion. Surface roughening is a temporary measure, and will not
provide long-term erosion control.
Surface Roughening (SR) EC-1
November 2010 Urban Drainage and Flood Control District SR-3
Urban Storm Drainage Criteria Manual Volume 3
EC-1 Surface Roughening (SR)
SR-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Temporary and Permanent Seeding (TS/PS) EC-2
June 2012 Urban Drainage and Flood Control District TS/PS-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph TS/PS -1. Equipment used to drill seed. Photo courtesy of
Douglas County.
Description
Temporary seeding can be used to
stabilize disturbed areas that will be
inactive for an extended period.
Permanent seeding should be used to
stabilize areas at final grade that will not
be otherwise stabilized. Effective seeding
includes preparation of a seedbed,
selection of an appropriate seed mixture,
proper planting techniques, and protection
of the seeded area with mulch, geotextiles,
or other appropriate measures.
Appropriate Uses
When the soil surface is disturbed and
will remain inactive for an extended
period (typically 30 days or longer),
proactive stabilization measures should be implemented. If the inactive period is short-lived (on the order
of two weeks), techniques such as surface roughening may be appropriate. For longer periods of
inactivity, temporary seeding and mulching can provide effective erosion control. Permanent seeding
should be used on finished areas that have not been otherwise stabilized.
Typically, local governments have their own seed mixes and timelines for seeding. Check jurisdictional
requirements for seeding and temporary stabilization.
Design and Installation
Effective seeding requires proper seedbed preparation, selection of an appropriate seed mixture, use of
appropriate seeding equipment to ensure proper coverage and density, and protection with mulch or fabric
until plants are established.
The USDCM Volume 2 Revegetation Chapter contains detailed seed mix, soil preparations, and seeding
and mulching recommendations that may be referenced to supplement this Fact Sheet.
Drill seeding is the preferred seeding method. Hydroseeding is not recommended except in areas where
steep slopes prevent use of drill seeding equipment, and even in these instances it is preferable to hand
seed and mulch. Some jurisdictions do not allow hydroseeding or hydromulching.
Seedbed Preparation
Prior to seeding, ensure that areas to be revegetated have
soil conditions capable of supporting vegetation. Overlot
grading can result in loss of topsoil, resulting in poor quality
subsoils at the ground surface that have low nutrient value,
little organic matter content, few soil microorganisms,
rooting restrictions, and conditions less conducive to
infiltration of precipitation. As a result, it is typically
necessary to provide stockpiled topsoil, compost, or other
Temporary and Permanent Seeding
Functions
Erosion Control Yes
Sediment Control No
Site/Material Management No
EC-2 Temporary and Permanent Seeding (TS/PS)
TS/PS-2 Urban Drainage and Flood Control District June 2012
Urban Storm Drainage Criteria Manual Volume 3
soil amendments and rototill them into the soil to a depth of 6 inches or more.
Topsoil should be salvaged during grading operations for use and spread on areas to be revegetated later.
Topsoil should be viewed as an important resource to be utilized for vegetation establishment, due to its
water-holding capacity, structure, texture, organic matter content, biological activity, and nutrient content.
The rooting depth of most native grasses in the semi-arid Denver metropolitan area is 6 to 18 inches. At a
minimum, the upper 6 inches of topsoil should be stripped, stockpiled, and ultimately respread across
areas that will be revegetated.
Where topsoil is not available, subsoils should be amended to provide an appropriate plant-growth
medium. Organic matter, such as well digested compost, can be added to improve soil characteristics
conducive to plant growth. Other treatments can be used to adjust soil pH conditions when needed. Soil
testing, which is typically inexpensive, should be completed to determine and optimize the types and
amounts of amendments that are required.
If the disturbed ground surface is compacted, rip or rototill the surface prior to placing topsoil. If adding
compost to the existing soil surface, rototilling is necessary. Surface roughening will assist in placement
of a stable topsoil layer on steeper slopes, and allow infiltration and root penetration to greater depth.
Prior to seeding, the soil surface should be rough and the seedbed should be firm, but neither too loose
nor compacted. The upper layer of soil should be in a condition suitable for seeding at the proper depth
and conducive to plant growth. Seed-to-soil contact is the key to good germination.
Seed Mix for Temporary Vegetation
To provide temporary vegetative cover on disturbed areas which will not be paved, built upon, or fully
landscaped or worked for an extended period (typically 30 days or more), plant an annual grass
appropriate for the time of planting and mulch the planted areas. Annual grasses suitable for the Denver
metropolitan area are listed in Table TS/PS-1. These are to be considered only as general
recommendations when specific design guidance for a particular site is not available. Local governments
typically specify seed mixes appropriate for their jurisdiction.
Seed Mix for Permanent Revegetation
To provide vegetative cover on disturbed areas that have reached final grade, a perennial grass mix should
be established. Permanent seeding should be performed promptly (typically within 14 days) after
reaching final grade. Each site will have different characteristics and a landscape professional or the local
jurisdiction should be contacted to determine the most suitable seed mix for a specific site. In lieu of a
specific recommendation, one of the perennial grass mixes appropriate for site conditions and growth
season listed in Table TS/PS-2 can be used. The pure live seed (PLS) rates of application recommended
in these tables are considered to be absolute minimum rates for seed applied using proper drill-seeding
equipment.
If desired for wildlife habitat or landscape diversity, shrubs such as rubber rabbitbrush (Chrysothamnus
nauseosus), fourwing saltbush (Atriplex canescens) and skunkbrush sumac (Rhus trilobata) could be
added to the upland seedmixes at 0.25, 0.5 and 1 pound PLS/acre, respectively. In riparian zones,
planting root stock of such species as American plum (Prunus americana), woods rose (Rosa woodsii),
plains cottonwood (Populus sargentii), and willow (Populus spp.) may be considered. On non-topsoiled
upland sites, a legume such as Ladak alfalfa at 1 pound PLS/acre can be included as a source of nitrogen
for perennial grasses.
Temporary and Permanent Seeding (TS/PS) EC-2
June 2012 Urban Drainage and Flood Control District TS/PS-3
Urban Storm Drainage Criteria Manual Volume 3
Seeding dates for the highest success probability of perennial species along the Front Range are generally
in the spring from April through early May and in the fall after the first of September until the ground
freezes. If the area is irrigated, seeding may occur in summer months, as well. See Table TS/PS-3 for
appropriate seeding dates.
Table TS/PS-1. Minimum Drill Seeding Rates for Various Temporary Annual Grasses
Speciesa
(Common name)
Growth
Seasonb
Pounds of
Pure Live Seed
(PLS)/acrec
Planting
Depth
(inches)
1. Oats Cool 35 - 50 1 - 2
2. Spring wheat Cool 25 - 35 1 - 2
3. Spring barley Cool 25 - 35 1 - 2
4. Annual ryegrass Cool 10 - 15 ½
5. Millet Warm 3 - 15 ½ - ¾
6. Sudangrass Warm 5–10 ½ - ¾
7. Sorghum Warm 5–10 ½ - ¾
8. Winter wheat Cool 20–35 1 - 2
9. Winter barley Cool 20–35 1 - 2
10. Winter rye Cool 20–35 1 - 2
11. Triticale Cool 25–40 1 - 2
a Successful seeding of annual grass resulting in adequate plant growth will
usually produce enough dead-plant residue to provide protection from
wind and water erosion for an additional year. This assumes that the cover
is not disturbed or mowed closer than 8 inches.
Hydraulic seeding may be substituted for drilling only where slopes are
steeper than 3:1 or where access limitations exist. When hydraulic
seeding is used, hydraulic mulching should be applied as a separate
operation, when practical, to prevent the seeds from being encapsulated in
the mulch.
b See Table TS/PS-3 for seeding dates. Irrigation, if consistently applied,
may extend the use of cool season species during the summer months.
c Seeding rates should be doubled if seed is broadcast, or increased by 50
percent if done using a Brillion Drill or by hydraulic seeding.
EC-2 Temporary and Permanent Seeding (TS/PS)
TS/PS-4 Urban Drainage and Flood Control District June 2012
Urban Storm Drainage Criteria Manual Volume 3
Table TS/PS-2. Minimum Drill Seeding Rates for Perennial Grasses
Commona
Name
Botanical
Name
Growth
Seasonb
Growth
Form
Seeds/
Pound
Pounds of
PLS/acre
Alakali Soil Seed Mix
Alkali sacaton Sporobolus airoides Cool Bunch 1,750,000 0.25
Basin wildrye Elymus cinereus Cool Bunch 165,000 2.5
Sodar streambank wheatgrass Agropyron riparium 'Sodar'Cool Sod 170,000 2.5
Jose tall wheatgrass Agropyron elongatum 'Jose'Cool Bunch 79,000 7.0
Arriba western wheatgrass Agropyron smithii 'Arriba'Cool Sod 110,000 5.5
Total 17.75
Fertile Loamy Soil Seed Mix
Ephriam crested wheatgrass Agropyron cristatum
'Ephriam'Cool Sod 175,000 2.0
Dural hard fescue Festuca ovina 'duriuscula'Cool Bunch 565,000 1.0
Lincoln smooth brome Bromus inermis leyss
'Lincoln'Cool Sod 130,000 3.0
Sodar streambank wheatgrass Agropyron riparium 'Sodar'Cool Sod 170,000 2.5
Arriba western wheatgrass Agropyron smithii 'Arriba'Cool Sod 110,000 7.0
Total 15.5
High Water Table Soil Seed Mix
Meadow foxtail Alopecurus pratensis Cool Sod 900,000 0.5
Redtop Agrostis alba Warm Open sod 5,000,000 0.25
Reed canarygrass Phalaris arundinacea Cool Sod 68,000 0.5
Lincoln smooth brome Bromus inermis leyss
'Lincoln'Cool Sod 130,000 3.0
Pathfinder switchgrass Panicum virgatum
'Pathfinder'Warm Sod 389,000 1.0
Alkar tall wheatgrass Agropyron elongatum
'Alkar'Cool Bunch 79,000 5.5
Total 10.75
Transition Turf Seed Mixc
Ruebens Canadian bluegrass Poa compressa 'Ruebens'Cool Sod 2,500,000 0.5
Dural hard fescue Festuca ovina 'duriuscula'Cool Bunch 565,000 1.0
Citation perennial ryegrass Lolium perenne 'Citation'Cool Sod 247,000 3.0
Lincoln smooth brome Bromus inermis leyss
'Lincoln'Cool Sod 130,000 3.0
Total 7.5
Temporary and Permanent Seeding (TS/PS) EC-2
June 2012 Urban Drainage and Flood Control District TS/PS-5
Urban Storm Drainage Criteria Manual Volume 3
Table TS/PS-2. Minimum Drill Seeding Rates for Perennial Grasses (cont.)
Common
Name
Botanical
Name
Growth
Seasonb
Growth
Form
Seeds/
Pound
Pounds of
PLS/acre
Sandy Soil Seed Mix
Blue grama Bouteloua gracilis Warm Sod-forming
bunchgrass 825,000 0.5
Camper little bluestem Schizachyrium scoparium
'Camper'Warm Bunch 240,000 1.0
Prairie sandreed Calamovilfa longifolia Warm Open sod 274,000 1.0
Sand dropseed Sporobolus cryptandrus Cool Bunch 5,298,000 0.25
Vaughn sideoats grama Bouteloua curtipendula
'Vaughn'Warm Sod 191,000 2.0
Arriba western wheatgrass Agropyron smithii 'Arriba'Cool Sod 110,000 5.5
Total 10.25
Heavy Clay, Rocky Foothill Seed Mix
Ephriam crested wheatgrassd Agropyron cristatum
'Ephriam'Cool Sod 175,000 1.5
Oahe Intermediate wheatgrass Agropyron intermedium
'Oahe'Cool Sod 115,000 5.5
Vaughn sideoats gramae Bouteloua curtipendula
'Vaughn'Warm Sod 191,000 2.0
Lincoln smooth brome Bromus inermis leyss
'Lincoln'Cool Sod 130,000 3.0
Arriba western wheatgrass Agropyron smithii 'Arriba'Cool Sod 110,000 5.5
Total 17.5
a All of the above seeding mixes and rates are based on drill seeding followed by crimped straw mulch. These rates should be
doubled if seed is broadcast and should be increased by 50 percent if the seeding is done using a Brillion Drill or is applied
through hydraulic seeding. Hydraulic seeding may be substituted for drilling only where slopes are steeper than 3:1. If
hydraulic seeding is used, hydraulic mulching should be done as a separate operation.
b See Table TS/PS-3 for seeding dates.
c If site is to be irrigated, the transition turf seed rates should be doubled.
d Crested wheatgrass should not be used on slopes steeper than 6H to 1V.
e Can substitute 0.5 lbs PLS of blue grama for the 2.0 lbs PLS of Vaughn sideoats grama.
EC-2 Temporary and Permanent Seeding (TS/PS)
TS/PS-6 Urban Drainage and Flood Control District June 2012
Urban Storm Drainage Criteria Manual Volume 3
Table TS/PS-3. Seeding Dates for Annual and Perennial Grasses
Annual Grasses
(Numbers in table reference
species in Table TS/PS-1)
Perennial Grasses
Seeding Dates Warm Cool Warm Cool
January 1–March 15 9 9
March 16–April 30 4 1,2,3 9 9
May 1–May 15 4 9
May 16–June 30 4,5,6,7
July 1–July 15 5,6,7
July 16–August 31
September 1–September 30 8,9,10,11
October 1–December 31 9 9
Mulch
Cover seeded areas with mulch or an appropriate rolled erosion control product to promote establishment
of vegetation. Anchor mulch by crimping, netting or use of a non-toxic tackifier. See the Mulching BMP
Fact Sheet for additional guidance.
Maintenance and Removal
Monitor and observe seeded areas to identify areas of poor growth or areas that fail to germinate. Reseed
and mulch these areas, as needed.
An area that has been permanently seeded should have a good stand of vegetation within one growing
season if irrigated and within three growing seasons without irrigation in Colorado. Reseed portions of
the site that fail to germinate or remain bare after the first growing season.
Seeded areas may require irrigation, particularly during extended dry periods. Targeted weed control may
also be necessary.
Protect seeded areas from construction equipment and vehicle access.
Soil Binders (SB) EC-3
November 2010 Urban Drainage and Flood Control District SB-1
Urban Storm Drainage Criteria Manual Volume 3
Description
Soil binders include a broad range of
treatments that can be applied to exposed
soils for temporary stabilization to reduce
wind and water erosion. Soil binders may
be applied alone or as tackifiers in
conjunction with mulching and seeding
applications.
Acknowledgement: This BMP Fact Sheet
has been adapted from the 2003
California Stormwater Quality
Association (CASQA) Stormwater BMP
Handbook: Construction
(www.cabmphandbooks.com).
Appropriate Uses
Soil binders can be used for short-term, temporary stabilization of soils on both mild and steep slopes.
Soil binders are often used in areas where work has temporarily stopped, but is expected to resume before
revegetation can become established. Binders are also useful on stockpiled soils or where temporary or
permanent seeding has occurred.
Prior to selecting a soil binder, check with the state and local jurisdiction to ensure that the chemicals
used in the soil binders are allowed. The water quality impacts of some types of soil binders are relatively
unknown and may not be allowed due to concerns about potential environmental impacts. Soil binders
must be environmentally benign (non-toxic to plant and animal life), easy to apply, easy to maintain,
economical, and should not stain paved or painted surfaces.
Soil binders should not be used in vehicle or pedestrian high traffic areas, due to loss in effectiveness
under these conditions.
Site soil type will dictate appropriate soil binders to be used. Be aware that soil binders may not function
effectively on silt or clay soils or highly compacted areas. Check manufacturer's recommendations for
appropriateness with regard to soil conditions. Some binders may not be suitable for areas with existing
vegetation.
Design and Installation
Properties of common soil binders used for erosion control
are provided in Table SB-1. Design and installation
guidance below are provided for general reference. Follow
the manufacturer's instructions for application rates and
procedures.
Soil Binders
Functions
Erosion Control Yes
Sediment Control No
Site/Material Management Moderate
Photograph SB-1.Tackifier being applied to provide temporary soil
stabilization. Photo courtesy of Douglas County.
EC-3 Soil Binders (SB)
SB-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Table SB-1. Properties of Soil Binders for Erosion Control (Source: CASQA 2003)
Evaluation Criteria
Binder Type
Plant Material
Based
(short lived)
Plant Material
Based
(long lived)
Polymeric
Emulsion Blends
Cementitious-
Based Binders
Resistance to Leaching High High Low to Moderate Moderate
Resistance to Abrasion Moderate Low Moderate to High Moderate to High
Longevity Short to Medium Medium Medium to Long Medium
Minimum Curing Time
before Rain 9 to 18 hours 19 to 24 hours 0 to 24 hours 4 to 8 hours
Compatibility with
Existing Vegetation Good Poor Poor Poor
Mode of Degradation Biodegradable Biodegradable
Photodegradable/
Chemically
Degradable
Photodegradable/
Chemically
Degradable
Specialized Application
Equipment
Water Truck or
Hydraulic
Mulcher
Water Truck or
Hydraulic
Mulcher
Water Truck or
Hydraulic Mulcher
Water Truck or
Hydraulic Mulcher
Liquid/Powder Powder Liquid Liquid/Powder Powder
Surface Crusting
Yes, but
dissolves on
rewetting
Yes Yes, but dissolves on
rewetting Yes
Clean Up Water Water Water Water
Erosion Control
Application Rate Varies Varies Varies 4,000 to 12,000
lbs/acre Typ.
Soil Binders (SB) EC-3
November 2010 Urban Drainage and Flood Control District SB-3
Urban Storm Drainage Criteria Manual Volume 3
Factors to consider when selecting a soil binder generally include:
Suitability to situation: Consider where the soil binder will be applied, if it needs a high resistance
to leaching or abrasion, and whether it needs to be compatible with existing vegetation. Determine
the length of time soil stabilization will be needed, and if the soil binder will be placed in an area
where it will degrade rapidly. In general, slope steepness is not a discriminating factor.
Soil types and surface materials: Fines and moisture content are key properties of surface
materials. Consider a soil binder's ability to penetrate, likelihood of leaching, and ability to form a
surface crust on the surface materials.
Frequency of application: The frequency of application can be affected by subgrade conditions,
surface type, climate, and maintenance schedule. Frequent applications could lead to high costs.
Application frequency may be minimized if the soil binder has good penetration, low evaporation,
and good longevity. Consider also that frequent application will require frequent equipment clean up.
An overview of major categories of soil binders, corresponding to the types included in Table SB-1
follows.
Plant-Material Based (Short Lived) Binders
Guar: A non-toxic, biodegradable, natural galactomannan-based hydrocolloid treated with dispersant
agents for easy field mixing. It should be mixed with water at the rate of 11 to 15 lbs per 1,000
gallons. Recommended minimum application rates are provided in Table SB-2.
Table SB-2. Application Rates for Guar Soil Stabilizer
Slope (H:V)
Flat 4:1 3:1 2:1 1:1
Application Rate (lb/acre)40 45 50 60 70
Psyllium: Composed of the finely ground muciloid coating of plantago seeds that is applied as a wet
slurry to the surface of the soil. It dries to form a firm but rewettable membrane that binds soil
particles together but permits germination and growth of seed. Psyllium requires 12 to 18 hours
drying time. Application rates should be from 80 to 200 lbs/acre, with enough water in solution to
allow for a uniform slurry flow.
Starch: Non-ionic, cold-water soluble (pre-gelatinized) granular cornstarch. The material is mixed
with water and applied at the rate of 150 lb/acre. Approximate drying time is 9 to 12 hours.
Plant-Material Based (Long Lived) Binders
Pitch and Rosin Emulsion: Generally, a non-ionic pitch and rosin emulsion has a minimum solids
content of 48 percent. The rosin should be a minimum of 26 percent of the total solids content. The
soil stabilizer should be a non-corrosive, water dilutable emulsion that upon application cures to a
water insoluble binding and cementing agent. For soil erosion control applications, the emulsion is
diluted and should be applied as follows:
o For clayey soil: 5 parts water to 1 part emulsion
EC-3 Soil Binders (SB)
SB-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
o For sandy soil: 10 parts water to 1 part emulsion
Application can be by water truck or hydraulic seeder with the emulsion and product mixture applied
at the rate specified by the manufacturer.
Polymeric Emulsion Blend Binders
Acrylic Copolymers and Polymers: Polymeric soil stabilizers should consist of a liquid or solid
polymer or copolymer with an acrylic base that contains a minimum of 55 percent solids. The
polymeric compound should be handled and mixed in a manner that will not cause foaming or should
contain an anti-foaming agent. The polymeric emulsion should not exceed its shelf life or expiration
date; manufacturers should provide the expiration date. Polymeric soil stabilizer should be readily
miscible in water, non-injurious to seed or animal life, non-flammable, should provide surface soil
stabilization for various soil types without inhibiting water infiltration, and should not re-emulsify
when cured. The applied compound should air cure within a maximum of 36 to 48 hours. Liquid
copolymer should be diluted at a rate of 10 parts water to 1 part polymer and the mixture applied to
soil at a rate of 1,175 gallons/acre.
Liquid Polymers of Methacrylates and Acrylates: This material consists of a tackifier/sealer that is
a liquid polymer of methacrylates and acrylates. It is an aqueous 100 percent acrylic emulsion blend
of 40 percent solids by volume that is free from styrene, acetate, vinyl, ethoxylated surfactants or
silicates. For soil stabilization applications, it is diluted with water in accordance with manufacturer's
recommendations, and applied with a hydraulic seeder at the rate of 20 gallons/acre. Drying time is
12 to 18 hours after application.
Copolymers of Sodium Acrylates and Acrylamides: These materials are non-toxic, dry powders
that are copolymers of sodium acrylate and acrylamide. They are mixed with water and applied to the
soil surface for erosion control at rates that are determined by slope gradient, as summarized in Table
SB-3.
Table SB-3. Application Rates for Copolymers of Sodium Acrylates and Acrylamides
Slope (H:V)
Flat to 5:1 5:1 to 3:1 2:2 to 1:1
Application Rate (lb/acre)3.0-5.0 5.0-10.0 10.0-20.0
Polyacrylamide and Copolymer of Acrylamide: Linear copolymer polyacrylamide is packaged as
a dry flowable solid. When used as a stand-alone stabilizer, it is diluted at a rate of 11 lb/1,000 gal. of
water and applied at the rate of 5.0 lb/acre.
Hydrocolloid Polymers: Hydrocolloid Polymers are various combinations of dry flowable
polyacrylamides, copolymers, and hydrocolloid polymers that are mixed with water and applied to the
soil surface at rates of 55 to 60 lb/acre. Drying times are 0 to 4 hours.
Cementitious-Based Binders
Gypsum: This formulated gypsum based product readily mixes with water and mulch to form a thin
protective crust on the soil surface. It is composed of high purity gypsum that is ground, calcined and
processed into calcium sulfate hemihydrate with a minimum purity of 86 percent. It is mixed in a
hydraulic seeder and applied at rates 4,000 to 12,000 lb/acre. Drying time is 4 to 8 hours.
Soil Binders (SB) EC-3
November 2010 Urban Drainage and Flood Control District SB-5
Urban Storm Drainage Criteria Manual Volume 3
Installation
After selecting an appropriate soil binder, the untreated soil surface must be prepared before applying the
soil binder. The untreated soil surface must contain sufficient moisture to assist the agent in achieving
uniform distribution. In general, the following steps should be followed:
Follow manufacturer's written recommendations for application rates, pre-wetting of application area,
and cleaning of equipment after use.
Prior to application, roughen embankment and fill areas.
Consider the drying time for the selected soil binder and apply with sufficient time before anticipated
rainfall. Soil binders should not be applied during or immediately before rainfall.
Avoid over spray onto roads, sidewalks, drainage channels, sound walls, existing vegetation, etc.
Soil binders should not be applied to frozen soil, areas with standing water, under freezing or rainy
conditions, or when the temperature is below 40°F during the curing period.
More than one treatment is often necessary, although the second treatment may be diluted or have a
lower application rate.
Generally, soil binders require a minimum curing time of 24 hours before they are fully effective.
Refer to manufacturer's instructions for specific cure time.
For liquid agents:
o Crown or slope ground to avoid ponding.
o Uniformly pre-wet ground at 0.03 to 0.3 gal/yd2 or according to manufacturer's recommendations.
o Apply solution under pressure. Overlap solution 6 to 12 in.
o Allow treated area to cure for the time recommended by the manufacturer, typically at least 24
hours.
o Apply second treatment before first treatment becomes ineffective, using 50 percent application
rate.
o In low humidity, reactivate chemicals by re-wetting with water at 0.1 to 0.2 gal/yd2.
Maintenance and Removal
Soil binders tend to break down due to natural weathering. Weathering rates depend on a variety of site-
specific and product characteristics. Consult the manufacturer for recommended reapplication rates and
reapply the selected soil binder as needed to maintain effectiveness.
Soil binders can fail after heavy rainfall events and may require reapplication. In particular, soil binders
will generally experience spot failures during heavy rainfall events. If runoff penetrates the soil at the top
of a slope treated with a soil binder, it is likely that the runoff will undercut the stabilized soil layer and
discharge at a point further down slope.
EC-3 Soil Binders (SB)
SB-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Areas where erosion is evident should be repaired and soil binder or other stabilization reapplied, as
needed. Care should be exercised to minimize the damage to protected areas while making repairs.
Most binders biodegrade after exposure to sun, oxidation, heat and biological organisms; therefore,
removal of the soil binder is not typically required.
Wind Erosion/Dust Control (DC) EC-14
November 2010 Urban Drainage and Flood Control District DC-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph DC-1. Water truck used for dust suppression. Photo
courtesy of Douglas County.
Description
Wind erosion and dust control BMPs
help to keep soil particles from entering
the air as a result of land disturbing
construction activities. These BMPs
include a variety of practices generally
focused on either graded disturbed areas
or construction roadways. For graded
areas, practices such as seeding and
mulching, use of soil binders, site
watering, or other practices that provide
prompt surface cover should be used.
For construction roadways, road
watering and stabilized surfaces should
be considered.
Appropriate Uses
Dust control measures should be used on any site where dust poses a problem to air quality. Dust control
is important to control for the health of construction workers and surrounding waterbodies.
Design and Installation
The following construction BMPs can be used for dust control:
An irrigation/sprinkler system can be used to wet the top layer of disturbed soil to help keep dry soil
particles from becoming airborne.
Seeding and mulching can be used to stabilize disturbed surfaces and reduce dust emissions.
Protecting existing vegetation can help to slow wind velocities across the ground surface, thereby
limiting the likelihood of soil particles to become airborne.
Spray-on soil binders form a bond between soil particles keeping them grounded. Chemical
treatments may require additional permitting requirements. Potential impacts to surrounding
waterways and habitat must be considered prior to use.
Placing rock on construction roadways and entrances will help keep dust to a minimum across the
construction site.
Wind fences can be installed on site to reduce wind
speeds. Install fences perpendicular to the prevailing
wind direction for maximum effectiveness.
Maintenance and Removal
When using an irrigation/sprinkler control system to aid in
dust control, be careful not to overwater. Overwatering will
cause construction vehicles to track mud off-site.
Wind Erosion Control/
Dust Control
Functions
Erosion Control Yes
Sediment Control No
Site/Material Management Moderate
Stockpile Management (SP) MM-2
November 2010 Urban Drainage and Flood Control District SP-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph SP-1. A topsoil stockpile that has been partially
revegetated and is protected by silt fence perimeter control.
Description
Stockpile management includes
measures to minimize erosion and
sediment transport from soil stockpiles.
Appropriate Uses
Stockpile management should be used
when soils or other erodible materials
are stored at the construction site.
Special attention should be given to
stockpiles in close proximity to natural
or manmade storm systems.
Design and Installation
Locate stockpiles away from all drainage system components including storm sewer inlets. Where
practical, choose stockpile locations that that will remain undisturbed for the longest period of time as the
phases of construction progress. Place sediment control BMPs around the perimeter of the stockpile, such
as sediment control logs, rock socks, silt fence, straw bales and sand bags. See Detail SP-1 for guidance
on proper establishment of perimeter controls around a stockpile. For stockpiles in active use, provide a
stabilized designated access point on the upgradient side of the stockpile.
Stabilize the stockpile surface with surface roughening, temporary seeding and mulching, erosion control
blankets, or soil binders. Soils stockpiled for an extended period (typically for more than 60 days) should
be seeded and mulched with a temporary grass cover once the stockpile is placed (typically within 14
days). Use of mulch only or a soil binder is acceptable if the stockpile will be in place for a more limited
time period (typically 30-60 days). Timeframes for stabilization of stockpiles noted in this fact sheet are
"typical" guidelines. Check permit requirements for specific federal, state, and/or local requirements that
may be more prescriptive.
Stockpiles should not be placed in streets or paved areas unless no other practical alternative exists. See
the Stabilized Staging Area Fact Sheet for guidance when staging in roadways is unavoidable due to
space or right-of-way constraints. For paved areas, rock socks must be used for perimeter control and all
inlets with the potential to receive sediment from the stockpile (even from vehicle tracking) must be
protected.
Maintenance and Removal
Inspect perimeter controls and inlet protection in accordance with their respective BMP Fact Sheets.
Where seeding, mulch and/or soil binders are used, reseeding or reapplication of soil binder may be
necessary.
When temporary removal of a perimeter BMP is necessary
to access a stockpile, ensure BMPs are reinstalled in
accordance with their respective design detail section.
Stockpile Management
Functions
Erosion Control Yes
Sediment Control Yes
Site/Material Management Yes
MM-2 Stockpile Management (SM)
SP-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
When the stockpile is no longer needed, properly dispose of excess materials and revegetate or otherwise
stabilize the ground surface where the stockpile was located.
Stockpile Management (SP) MM-2
November 2010 Urban Drainage and Flood Control District SP-3
Urban Storm Drainage Criteria Manual Volume 3
MM-2 Stockpile Management (SM)
SP-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Stockpile Management (SP) MM-2
November 2010 Urban Drainage and Flood Control District SP-5
Urban Storm Drainage Criteria Manual Volume 3
MM-2 Stockpile Management (SM)
SP-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Good Housekeeping Practices (GH) MM-3
November 2010 Urban Drainage and Flood Control District GH-1
Urban Storm Drainage Criteria Manual Volume 3
Photographs GH-1 and GH-2. Proper materials
storage and secondary containment for fuel tanks
are important good housekeeping practices. Photos
courtesy of CDOT and City of Aurora.
Description
Implement construction site good housekeeping practices to
prevent pollution associated with solid, liquid and hazardous
construction-related materials and wastes. Stormwater
Management Plans (SWMPs) should clearly specify BMPs
including these good housekeeping practices:
Provide for waste management.
Establish proper building material staging areas.
Designate paint and concrete washout areas.
Establish proper equipment/vehicle fueling and
maintenance practices.
Control equipment/vehicle washing and allowable non-
stormwater discharges.
Develop a spill prevention and response plan.
Acknowledgement: This Fact Sheet is based directly on
EPA guidance provided in Developing Your Stormwater
Pollution Prevent Plan (EPA 2007).
Appropriate Uses
Good housekeeping practices are necessary at all construction sites.
Design and Installation
The following principles and actions should be addressed in SWMPs:
Provide for Waste Management.Implement management procedures and practices to prevent or
reduce the exposure and transport of pollutants in stormwater from solid, liquid and sanitary wastes
that will be generated at the site. Practices such as trash disposal, recycling, proper material handling,
and cleanup measures can reduce the potential for stormwater runoff to pick up construction site
wastes and discharge them to surface waters. Implement a comprehensive set of waste-management
practices for hazardous or toxic materials, such as paints, solvents, petroleum products, pesticides,
wood preservatives, acids, roofing tar, and other materials. Practices should include storage,
handling, inventory, and cleanup procedures, in case of spills. Specific practices that should be
considered include:
Solid or Construction Waste
o Designate trash and bulk waste-collection areas on-
site.
Good Housekeeping
Functions
Erosion Control No
Sediment Control No
Site/Material Management Yes
MM-3 Good Housekeeping Practices (GH)
GH-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Photograph GH-3. Locate portable toilet facilities on level
surfaces away from waterways and storm drains. Photo
courtesy of WWE.
o Recycle materials whenever possible (e.g., paper, wood, concrete, oil).
o Segregate and provide proper disposal options for hazardous material wastes.
o Clean up litter and debris from the construction site daily.
o Locate waste-collection areas away from streets, gutters, watercourses, and storm drains. Waste-
collection areas (dumpsters, and such) are often best located near construction site entrances to
minimize traffic on disturbed soils. Consider secondary containment around waste collection
areas to minimize the likelihood of contaminated discharges.
o Empty waste containers before they are full and overflowing.
Sanitary and Septic Waste
o Provide convenient, well-maintained, and properly located toilet facilities on-site.
o Locate toilet facilities away from storm drain inlets and waterways to prevent accidental spills
and contamination of stormwater.
o Maintain clean restroom facilities and empty portable toilets regularly.
o Where possible, provide secondary containment pans under portable toilets.
o Provide tie-downs or stake-downs for portable toilets.
o Educate employees, subcontractors, and suppliers on locations of facilities.
o Treat or dispose of sanitary and septic waste in accordance with state or local regulations. Do not
discharge or bury wastewater at the construction site.
o Inspect facilities for leaks. If found, repair or replace immediately.
o Special care is necessary during maintenance (pump out) to ensure that waste and/or biocide are
not spilled on the ground.
Hazardous Materials and Wastes
o Develop and implement employee and
subcontractor education, as needed, on
hazardous and toxic waste handling,
storage, disposal, and cleanup.
o Designate hazardous waste-collection
areas on-site.
o Place all hazardous and toxic material
wastes in secondary containment.
Good Housekeeping Practices (GH) MM-3
November 2010 Urban Drainage and Flood Control District GH-3
Urban Storm Drainage Criteria Manual Volume 3
o Hazardous waste containers should be inspected to ensure that all containers are labeled properly
and that no leaks are present.
Establish Proper Building Material Handling and Staging Areas. The SWMP should include
comprehensive handling and management procedures for building materials, especially those that are
hazardous or toxic. Paints, solvents, pesticides, fuels and oils, other hazardous materials or building
materials that have the potential to contaminate stormwater should be stored indoors or under cover
whenever possible or in areas with secondary containment. Secondary containment measures prevent
a spill from spreading across the site and may include dikes, berms, curbing, or other containment
methods. Secondary containment techniques should also ensure the protection of groundwater.
Designate staging areas for activities such as fueling vehicles, mixing paints, plaster, mortar, and
other potential pollutants. Designated staging areas enable easier monitoring of the use of materials
and clean up of spills. Training employees and subcontractors is essential to the success of this
pollution prevention principle. Consider the following specific materials handling and staging
practices:
o Train employees and subcontractors in proper handling and storage practices.
o Clearly designate site areas for staging and storage with signs and on construction drawings.
Staging areas should be located in areas central to the construction site. Segment the staging area
into sub-areas designated for vehicles, equipment, or stockpiles. Construction entrances and exits
should be clearly marked so that delivery vehicles enter/exit through stabilized areas with vehicle
tracking controls (See Vehicle Tracking Control Fact Sheet).
o Provide storage in accordance with Spill Protection, Control and Countermeasures (SPCC)
requirements and plans and provide cover and impermeable perimeter control, as necessary, for
hazardous materials and contaminated soils that must be stored on site.
o Ensure that storage containers are regularly inspected for leaks, corrosion, support or foundation
failure, or other signs of deterioration and tested for soundness.
o Reuse and recycle construction materials when possible.
Designate Concrete Washout Areas. Concrete contractors should be encouraged to use the washout
facilities at their own plants or dispatch facilities when feasible; however, concrete washout
commonly occurs on construction sites. If it is necessary to provide for concrete washout areas on-
site, designate specific washout areas and design facilities to handle anticipated washout water.
Washout areas should also be provided for paint and stucco operations. Because washout areas can
be a source of pollutants from leaks or spills, care must be taken with regard to their placement and
proper use. See the Concrete Washout Area Fact Sheet for detailed guidance.
Both self-constructed and prefabricated washout containers can fill up quickly when concrete, paint,
and stucco work are occurring on large portions of the site. Be sure to check for evidence that
contractors are using the washout areas and not dumping materials onto the ground or into drainage
facilities. If the washout areas are not being used regularly, consider posting additional signage,
relocating the facilities to more convenient locations, or providing training to workers and
contractors.
When concrete, paint, or stucco is part of the construction process, consider these practices which will
help prevent contamination of stormwater. Include the locations of these areas and the maintenance
and inspection procedures in the SWMP.
MM-3 Good Housekeeping Practices (GH)
GH-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
o Do not washout concrete trucks or equipment into storm drains, streets, gutters, uncontained
areas, or streams. Only use designated washout areas.
o Establish washout areas and advertise their locations with signs. Ensure that signage remains in
good repair.
o Provide adequate containment for the amount of wash water that will be used.
o Inspect washout structures daily to detect leaks or tears and to identify when materials need to be
removed.
o Dispose of materials properly. The preferred method is to allow the water to evaporate and to
recycle the hardened concrete. Full service companies may provide dewatering services and
should dispose of wastewater properly. Concrete wash water can be highly polluted. It should
not be discharged to any surface water, storm sewer system, or allowed to infiltrate into the
ground in the vicinity of waterbodies. Washwater should not be discharged to a sanitary sewer
system without first receiving written permission from the system operator.
Establish Proper Equipment/Vehicle Fueling and Maintenance Practices. Create a clearly
designated on-site fueling and maintenance area that is clean and dry. The on-site fueling area should
have a spill kit, and staff should know how to use it. If possible, conduct vehicle fueling and
maintenance activities in a covered area. Consider the following practices to help prevent the
discharge of pollutants to stormwater from equipment/vehicle fueling and maintenance. Include the
locations of designated fueling and maintenance areas and inspection and maintenance procedures in
the SWMP.
o Train employees and subcontractors in proper fueling procedures (stay with vehicles during
fueling, proper use of pumps, emergency shutoff valves, etc.).
o Inspect on-site vehicles and equipment regularly for leaks, equipment damage, and other service
problems.
o Clearly designate vehicle/equipment service areas away from drainage facilities and watercourses
to prevent stormwater run-on and runoff.
o Use drip pans, drip cloths, or absorbent pads when replacing spent fluids.
o Collect all spent fluids, store in appropriate labeled containers in the proper storage areas, and
recycle fluids whenever possible.
Control Equipment/Vehicle Washing and Allowable Non-Stormwater Discharges.Implement
practices to prevent contamination of surface and groundwater from equipment and vehicle wash
water. Representative practices include:
o Educate employees and subcontractors on proper washing procedures.
o Use off-site washing facilities, when available.
o Clearly mark the washing areas and inform workers that all washing must occur in this area.
o Contain wash water and treat it using BMPs. Infiltrate washwater when possible, but maintain
separation from drainage paths and waterbodies.
Good Housekeeping Practices (GH) MM-3
November 2010 Urban Drainage and Flood Control District GH-5
Urban Storm Drainage Criteria Manual Volume 3
o Use high-pressure water spray at vehicle washing facilities without detergents. Water alone can
remove most dirt adequately.
o Do not conduct other activities, such as vehicle repairs, in the wash area.
o Include the location of the washing facilities and the inspection and maintenance procedures in
the SWMP.
Develop a Spill Prevention and Response Plan.Spill prevention and response procedures must be
identified in the SWMP. Representative procedures include identifying ways to reduce the chance of
spills, stop the source of spills, contain and clean up spills, dispose of materials contaminated by
spills, and train personnel responsible for spill prevention and response. The plan should also specify
material handling procedures and storage requirements and ensure that clear and concise spill cleanup
procedures are provided and posted for areas in which spills may potentially occur. When developing
a spill prevention plan, include the following:
o Note the locations of chemical storage areas, storm drains, tributary drainage areas, surface
waterbodies on or near the site, and measures to stop spills from leaving the site.
o Provide proper handling and safety procedures for each type of waste. Keep Material Safety Data
Sheets (MSDSs) for chemical used on site with the SWMP.
o Establish an education program for employees and subcontractors on the potential hazards to
humans and the environment from spills and leaks.
o Specify how to notify appropriate authorities, such as police and fire departments, hospitals, or
municipal sewage treatment facilities to request assistance. Emergency procedures and contact
numbers should be provided in the SWMP and posted at storage locations.
o Describe the procedures, equipment and materials for immediate cleanup of spills and proper
disposal.
o Identify personnel responsible for implementing the plan in the event of a spill. Update the spill
prevention plan and clean up materials as changes occur to the types of chemicals stored and used
at the facility.
MM-3 Good Housekeeping Practices (GH)
GH-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Spill Prevention, Control, and Countermeasure (SPCC) Plan
Construction sites may be subject to 40 CFR Part 112 regulations that require the preparation and
implementation of a SPCC Plan to prevent oil spills from aboveground and underground storage tanks.
The facility is subject to this rule if it is a non-transportation-related facility that:
Has a total storage capacity greater than 1,320 gallons or a completely buried storage capacity
greater than 42,000 gallons.
Could reasonably be expected to discharge oil in quantities that may be harmful to navigable waters
of the United States and adjoining shorelines.
Furthermore, if the facility is subject to 40 CFR Part 112, the SWMP should reference the SPCC Plan.
To find out more about SPCC Plans, see EPA's website on SPPC at www.epa.gov/oilspill/spcc.htm.
Reporting Oil Spills
In the event of an oil spill, contact the National Response Center toll free at 1-800-424- 8802 for
assistance, or for more details, visit their website: www.nrc.uscg.mil.
Maintenance and Removal
Effective implementation of good housekeeping practices is dependent on clear designation of personnel
responsible for supervising and implementing good housekeeping programs, such as site cleanup and
disposal of trash and debris, hazardous material management and disposal, vehicle and equipment
maintenance, and other practices. Emergency response "drills" may aid in emergency preparedness.
Checklists may be helpful in good housekeeping efforts.
Staging and storage areas require permanent stabilization when the areas are no longer being used for
construction-related activities.
Construction-related materials, debris and waste must be removed from the construction site once
construction is complete.
Design Details
See the following Fact Sheets for related Design Details:
MM-1 Concrete Washout Area
MM-2 Stockpile Management
SM-4 Vehicle Tracking Control
Design details are not necessary for other good housekeeping practices; however, be sure to designate
where specific practices will occur on the appropriate construction drawings.
Silt Fence (SF) SC-1
November 2010 Urban Drainage and Flood Control District SF-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph SF-1.Silt fence creates a sediment barrier, forcing
sheet flow runoff to evaporate or infiltrate.
Description
A silt fence is a woven geotextile fabric
attached to wooden posts and trenched
into the ground. It is designed as a
sediment barrier to intercept sheet flow
runoff from disturbed areas.
Appropriate Uses
A silt fence can be used where runoff is
conveyed from a disturbed area as sheet
flow. Silt fence is not designed to
receive concentrated flow or to be used
as a filter fabric. Typical uses include:
Down slope of a disturbed area to
accept sheet flow.
Along the perimeter of a receiving
water such as a stream, pond or
wetland.
At the perimeter of a construction site.
Design and Installation
Silt fence should be installed along the contour of slopes so that it intercepts sheet flow. The maximum
recommended tributary drainage area per 100 lineal feet of silt fence, installed along the contour, is
approximately 0.25 acres with a disturbed slope length of up to 150 feet and a tributary slope gradient no
steeper than 3:1. Longer and steeper slopes require additional measures. This recommendation only
applies to silt fence installed along the contour. Silt fence installed for other uses, such as perimeter
control, should be installed in a way that will not produce concentrated flows. For example, a "J-hook"
installation may be appropriate to force runoff to pond and evaporate or infiltrate in multiple areas rather
than concentrate and cause erosive conditions parallel to the silt fence.
See Detail SF-1 for proper silt fence installation, which involves proper trenching, staking, securing the
fabric to the stakes, and backfilling the silt fence. Properly installed silt fence should not be easily pulled
out by hand and there should be no gaps between the ground and the fabric.
Silt fence must meet the minimum allowable strength requirements, depth of installation requirement, and
other specifications in the design details. Improper installation
of silt fence is a common reason for silt fence failure; however,
when properly installed and used for the appropriate purposes, it
can be highly effective.
Silt Fence
Functions
Erosion Control No
Sediment Control Yes
Site/Material Management No
SC-1 Silt Fence (SF)
SF-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Photograph SF-2.When silt fence is not installed along
the contour, a "J-hook" installation may be appropriate
to ensure that the BMP does not create concentrated
flow parallel to the silt fence. Photo courtesy of Tom
Gore.
Maintenance and Removal
Inspection of silt fence includes observing the
material for tears or holes and checking for slumping
fence and undercut areas bypassing flows. Repair of
silt fence typically involves replacing the damaged
section with a new section. Sediment accumulated
behind silt fence should be removed, as needed to
maintain BMP effectiveness, typically before it
reaches a depth of 6 inches.
Silt fence may be removed when the upstream area
has reached final stabilization.
Silt Fence (SF) SC-1
November 2010 Urban Drainage and Flood Control District SF-3
Urban Storm Drainage Criteria Manual Volume 3
SC-1 Silt Fence (SF)
SF-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Sediment Control Log (SCL) SC-2
November 2010 Urban Drainage and Flood Control District SCL-1
Urban Storm Drainage Criteria Manual Volume 3
Photographs SCL-1 and SCL-2. Sediment control logs used as 1) a
perimeter control around a soil stockpile; and, 2) as a "J-hook"
perimeter control at the corner of a construction site.
Description
A sediment control log is a linear roll
made of natural materials such as
straw, coconut fiber, or other fibrous
material trenched into the ground and
held with a wooden stake. Sediment
control logs are also often referred to
as "straw wattles." They are used as a
sediment barrier to intercept sheet flow
runoff from disturbed areas.
Appropriate Uses
Sediment control logs can be used in
the following applications to trap
sediment:
As perimeter control for stockpiles
and the site.
As part of inlet protection designs.
As check dams in small drainage
ditches. (Sediment control logs
are not intended for use in
channels with high flow
velocities.)
On disturbed slopes to shorten flow
lengths (as an erosion control).
As part of multi-layered perimeter control along a receiving water such as a stream, pond or wetland.
Sediment control logs work well in combination with other layers of erosion and sediment controls.
Design and Installation
Sediment control logs should be installed along the contour to avoid concentrating flows. The maximum
allowable tributary drainage area per 100 lineal feet of sediment control log, installed along the contour, is
approximately 0.25 acres with a disturbed slope length of up to 150 feet and a tributary slope gradient no
steeper than 3:1. Longer and steeper slopes require additional measures. This recommendation only
applies to sediment control logs installed along the contour. When installed for other uses, such as
perimeter control, it should be installed in a way that will not
produce concentrated flows. For example, a "J-hook"
installation may be appropriate to force runoff to pond and
evaporate or infiltrate in multiple areas rather than concentrate
and cause erosive conditions parallel to the BMP.
Sediment Control Log
Functions
Erosion Control Moderate
Sediment Control Yes
Site/Material Management No
SC-2 Sediment Control Log (SCL)
SCL-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Although sediment control logs initially allow runoff to flow through the BMP, they can quickly become
a barrier and should be installed is if they are impermeable.
Design details and notes for sediment control logs are provided in Detail SCL-1. Sediment logs must be
properly trenched and staked into the ground to prevent undercutting, bypassing and displacement. When
installed on slopes, sediment control logs should be installed along the contours (i.e., perpendicular to
flow).
Improper installation can lead to poor performance. Be sure that sediment control logs are properly
trenched, anchored and tightly jointed.
Maintenance and Removal
Be aware that sediment control logs will eventually degrade. Remove accumulated sediment before the
depth is one-half the height of the sediment log and repair damage to the sediment log, typically by
replacing the damaged section.
Once the upstream area is stabilized, remove and properly dispose of the logs. Areas disturbed beneath
the logs may need to be seeded and mulched. Sediment control logs that are biodegradable may
occasionally be left in place (e.g., when logs are used in conjunction with erosion control blankets as
permanent slope breaks). However, removal of sediment control logs after final stabilization is typically
recommended when used in perimeter control, inlet protection and check dam applications.
Sediment Control Log (SCL) SC-2
November 2010 Urban Drainage and Flood Control District SCL-3
Urban Storm Drainage Criteria Manual Volume 3
SC-2 Sediment Control Log (SCL)
SCL-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Sediment Control Log (SCL) SC-2
November 2010 Urban Drainage and Flood Control District SCL-5
Urban Storm Drainage Criteria Manual Volume 3
Vehicle Tracking Control (VTC) SM-4
November 2010 Urban Drainage and Flood Control District VTC-1
Urban Storm Drainage Criteria Manual Volume 3
Photograph VTC-1. A vehicle tracking control pad constructed with
properly sized rock reduces off-site sediment tracking.
Description
Vehicle tracking controls provide
stabilized construction site access where
vehicles exit the site onto paved public
roads. An effective vehicle tracking
control helps remove sediment (mud or
dirt) from vehicles, reducing tracking onto
the paved surface.
Appropriate Uses
Implement a stabilized construction
entrance or vehicle tracking control where
frequent heavy vehicle traffic exits the
construction site onto a paved roadway. An
effective vehicle tracking control is
particularly important during the following conditions:
Wet weather periods when mud is easily tracked off site.
During dry weather periods where dust is a concern.
When poorly drained, clayey soils are present on site.
Although wheel washes are not required in designs of vehicle tracking controls, they may be needed at
particularly muddy sites.
Design and Installation
Construct the vehicle tracking control on a level surface. Where feasible, grade the tracking control
towards the construction site to reduce off-site runoff. Place signage, as needed, to direct construction
vehicles to the designated exit through the vehicle tracking control. There are several different types of
stabilized construction entrances including:
VTC-1. Aggregate Vehicle Tracking Control. This is a coarse-aggregate surfaced pad underlain by a
geotextile. This is the most common vehicle tracking control, and when properly maintained can be
effective at removing sediment from vehicle tires.
VTC-2. Vehicle Tracking Control with Construction Mat or Turf Reinforcement Mat. This type of
control may be appropriate for site access at very small construction sites with low traffic volume over
vegetated areas. Although this application does not typically remove sediment from vehicles, it helps
protect existing vegetation and provides a stabilized entrance.
Vehicle Tracking Control
Functions
Erosion Control Moderate
Sediment Control Yes
Site/Material Management Yes
SM-4 Vehicle Tracking Control (VTC)
VTC-2 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Photograph VTC-2. A vehicle tracking control pad with wheel wash
facility. Photo courtesy of Tom Gore.
VTC-3. Stabilized Construction Entrance/Exit with Wheel Wash. This is an aggregate pad, similar
to VTC-1, but includes equipment for tire washing. The wheel wash equipment may be as simple as
hand-held power washing equipment to more advance proprietary systems. When a wheel wash is
provided, it is important to direct wash water to a sediment trap prior to discharge from the site.
Vehicle tracking controls are sometimes installed in combination with a sediment trap to treat runoff.
Maintenance and Removal
Inspect the area for degradation and
replace aggregate or material used for a
stabilized entrance/exit as needed. If the
area becomes clogged and ponds water,
remove and dispose of excess sediment
or replace material with a fresh layer of
aggregate as necessary.
With aggregate vehicle tracking controls,
ensure rock and debris from this area do
not enter the public right-of-way.
Remove sediment that is tracked onto the
public right of way daily or more
frequently as needed. Excess sediment
in the roadway indicates that the
stabilized construction entrance needs
maintenance.
Ensure that drainage ditches at the
entrance/exit area remain clear.
A stabilized entrance should be removed only when there is no longer the potential for vehicle tracking to
occur. This is typically after the site has been stabilized.
When wheel wash equipment is used, be sure that the wash water is discharged to a sediment trap prior to
discharge. Also inspect channels conveying the water from the wash area to the sediment trap and
stabilize areas that may be eroding.
When a construction entrance/exit is removed, excess sediment from the aggregate should be removed
and disposed of appropriately. The entrance should be promptly stabilized with a permanent surface
following removal, typically by paving.
Vehicle Tracking Control (VTC) SM-4
November 2010 Urban Drainage and Flood Control District VTC-3
Urban Storm Drainage Criteria Manual Volume 3
SM-4 Vehicle Tracking Control (VTC)
VTC-4 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
Vehicle Tracking Control (VTC) SM-4
November 2010 Urban Drainage and Flood Control District VTC-5
Urban Storm Drainage Criteria Manual Volume 3
SM-4 Vehicle Tracking Control (VTC)
VTC-6 Urban Drainage and Flood Control District November 2010
Urban Storm Drainage Criteria Manual Volume 3
APPENDIX D
EROSION CONTROL PLAN
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