HomeMy WebLinkAboutAVONDALE COTTAGES - FDP - FDP140018 - SUBMITTAL DOCUMENTS - ROUND 1 - STORMWATER MANAGEMENT PLANEROSION CONTROL REPORT/STORMWATER MANAGEMENT PLAN
FOR
Avondale Cottages
Ridgewood Hills PUD
Prepared by:
Interwest Consulting Group
1218 West Ash, Suite C
Windsor, Colorado 80550
Phone: 970.674.3300
Fax: 970.674.3303
Prepared for:
Habitat For Humanity
4001 S. Taft Hill Road
Fort Collins, Colorado 80525
Phone: 970.223.4522
Fax: 970.223.4524
August 6, 2014
August 6, 2014
Mr. Jesse Schlam
City of Fort Collins Stormwater
700 Wood Street
Fort Collins, CO 80522-0580
RE: Erosion Control Report /Stormwater Management Plan for Avondale Cottages
Dear Jesse,
I am pleased to submit for your review and approval, this Erosion Control Report/Stormwater
Management Plan for the Avondale Cottages development. This report provides the City with an
erosion control plan for the proposed development that addresses the topics outlined in the City
Erosion Control Report Requirements. This plan mimics the State of Colorado General Permit
and Stormwater Management Plan requirements.
I appreciate your time and consideration in reviewing this submittal. Please call if you have any
questions.
Sincerely,
Jason T. Claeys, P.E., LEED AP
Interwest Consulting Group
TABLE OF CONTENTS
1. INTRODUCTION .................................................................................................................... 1
2. SITE DESCRIPTION ............................................................................................................... 1
3. BMPS FOR STORMWATER POLLUTION PREVENTION ................................................ 5
3.1. Erosion and Sediment Controls ........................................................................................ 5
3.2 Materials Handling and Spill Prevention ......................................................................... 8
4. STORMWATER MANAGEMENT CONTROLS ................................................................ 10
4.1. SWMP Administrator ..................................................................................................... 10
4.2. Identification of Potential Pollution Sources ................................................................. 10
5. FINAL STABILIZATION AND LONG TERM STORMWATER MANAGEMENT ......... 12
6. INSPECTION AND MAINTENANCE ................................................................................. 12
6.1. City of Fort Collins Standard Erosion and Sediment Control Notes ............................. 12
6.2. City of Fort Collins Erosion Control Security Calculations ........................................... 14
7. SWMP IMPLEMENTATION................................................................................................ 16
APPENDIX A—BMP DETAILS ................................................................................................ A
APPENDIX B—EROSION CONTROL PLAN AND SITE MAP ........................................... B
APPENDIX C—CONSTRUCTION SEQUENCE .................................................................... C
APPENDIX D—SOIL INFORMATION ................................................................................... D
LIST OF FIGURES
Figure 1—Vicinity Map…………………………………………………………………………..2
LIST OF TABLES
Table 2.1—On-site Soil Characteristics…………………………………………………………..3
Table 2.2—Sub-Basin Characteristics…………………...……………………………………….4
Table 6.1—Erosion Control Cost Estimate……………………………………………………...15
1
1. INTRODUCTION
The primary purpose of preparing and maintaining a stormwater management plan is to
improve the health and quality of the State's urban waterways. The preparation and
maintenance of the plan will contribute to this objective by facilitating an approach to
stormwater management, establishing a program of actions to be used during construction
activities, and describing stormwater management controls and various Best Management
Practices (BMPs) necessary to reduce erosion, sediment and pollutants in stormwater
discharge.
Information concerning the State of Colorado General Permit and Stormwater
Management Plan are not included in the appendices of this report. The site is over one
acre and will require a SWMP permit.
2. SITE DESCRIPTION
This site is legally known as Tract L of Ridgewood Hills PUD – First Filing. It is located
in the northeast quarter of Section 14, Township 6 North, Range 69 West of the Sixth
Principal Meridian, in the City of Fort Collins, Larimer County, Colorado. See Figure 1
for a vicinity map.
The project includes 1.51 acres and is bounded by W. Trilby Road to the north, Avondale
Road to the west, a daycare and condos to the south, and a regional detention pond to the
east. The site was originally anticipated to be commercial uses with a convenience store
and office/retail buildings. The proposed use is residential with six single family homes
and two duplex units.
The site is currently vacant with what appears to be native vegetation. The property line
to the south splits the existing private drive with the daycare. A portion of this drive is
located on the Avondale Cottage site. The majority of the daycare site drains onto the
Avondale Cottage site, and a limited area at the rear of the condos drains to this site.
Currently runoff is conveyed via overland flow and a small drainage swale/depression,
and as intended, ultimately drains to the regional detention pond.
2
Figure 1--Vicinity Map
3
Existing soil types on site as classified by the NRCS Soil Survey of Larimer County are
classified as Cushman Fine Sandy Loam and Thedalund Loam. Please refer to Table 2.1
for additional soil characteristics.
Table 2.1: On-site Soil Characteristics
Soil Type
Percent of
Site
Hydrologic
Soil Group
K
Factor1
Wind
Group2
Cushman Fine Sandy Loam 32% C 0.24 3
Thedalund Loam 67% C 0.37 4L
1K factors range from 0.24 to 0.37. The higher value, the more susceptible the soil is to sheet and
rill erosion by water.
2Soils assigned to wind group 1 are the most susceptible to wind erosion, soils assigned to wind
group 8 are the least susceptible.
Overall, the soils on site can be classified as moderately erodible. Please refer to
Appendix D for the on-site soil information from the NRCS Soil Survey of Larimer
County.
The majority of the proposed development runoff will be collected and conveyed to the
proposed extended detention basins in the southwest and northwest portions of the site
where it will be allowed to settle before being released into the adjoining drainage
easement to the west of the property.
With the building addition, the majority of water will sheet to proposed extended
detention basins, while the remainder will be collected in the small on-site storm sewer
system and piped to Extended Detention Basin B. All paved areas are designed with a
minimum slope of 0.5% and all grassed areas are designed with a minimum slope of
2.0%. Side slopes in grassed areas are graded to a maximum of 4:1.
4
The anticipated sequence of construction shall progress as follows:
1) Installation of perimeter and offsite erosion control measures (outlet protection at
the regional pond outlet structure, rock sock at the existing private drive curb cut
east of the project, inlet protection at the existing inlets on Trilby Rd and
Avondale Rd, perimeter silt fence and construction fence). Other measures as
required for erosion control will be constructed throughout the project.
2) Clearing, stripping and grading
3) Utility installation
4) Sub-grade preparation for the drives and sidewalks
5) Curb, gutter and sidewalks
6) Paving
7) Building construction (this may occur simultaneously with items 5 through 7)
8) Final grading and landscaping. All disturbed ground will be impervious (concrete,
asphalt, or building), seeded and mulched, sodded or xeriscaped to permanently
stabilize the site. The rain garden will be completed at this time as well.
The run-off coefficients associated with this project for onsite Sub-Basins are as follows:
Table 2.2: Sub-Basin Characteristics
Sub-Basin Area (AC) C2 C10 C100
D1 0.96 0.38 0. 49 0.62
D2 0.15 0.29 0.42 0.59
D3 0.11 0.51 0.59 0.69
OF1 0.47 0.50 0.58 0.68
OF2 0.39 0.23 0.38 0.57
No outside sources of pollution currently exist on this site. Potential pollutant sources
brought onto the site during construction will be discussed (along with spill prevention)
in Section 3.2 below. The anticipated non-stormwater components of discharge with this
project are landscape irrigation return flows. Runoff from the site will flow toward the
centrally located rain garden and then be conveyed through a pipe network to the existing
regional detention pond located east of the site. This detention pond discharges under
Trilby Rd. in an existing 18” culvert and ultimately drains into Fossil Creek.
5
3. BMPS FOR STORMWATER POLLUTION PREVENTION
3.1. Erosion and Sediment Controls
Structural Practices: Structural practices for the site will consist mainly of vehicle
tracking pad, concrete washout area, silt fence, temporary sediment basin (ultimate
location of the rain garden), inlet protection, outlet structure protection and sediment
control logs which are described in detail in the following paragraphs. Detail drawings of
these BMPs are also included in Appendix A. These BMPs are expected to change as the
construction progresses and it is the responsibility of the contractor to ensure appropriate
BMPs are in place and/or removed at the appropriate time in the construction sequence.
All temporary and permanent erosion and sediment control practices must be maintained
and repaired as needed to assure continued performance of their intended function. All
BMPs shall be inspected and repaired or replaced as indicated in Section 6 and as
required to satisfy the conditions of the Permit.
Vehicle tracking pad is intended to trap mud and sediment within coarse grain material
and provide clean access to public roadways. Wherever construction vehicle access routes
intersect paved public roads a vehicle tracking control pad shall be installed to minimize
the transport of sediment (mud) by runoff or vehicles tracking onto the paved surface.
Pads shall be maintained and refurbished when necessary to obtain their intended result.
Concrete washout area is intended to contain washout liquids and solids that result from
the cleaning of concrete trucks and pumps. Washouts should be placed near the area
where the concrete is being poured.
Silt fence prevents sediment from leaving the site during a runoff event by collecting the
deposits along the fence line while allowing the storm water to seep through. Silt fence
shall be placed along the east boundary of the site to prevent sediment transport into the
existing detention pond. Silt fence shall be inspected and maintained after every rainfall
event that produces runoff. Sediment must be removed and rocks replaced. Silt fence
shall be installed prior to any work commencing on-site.
Temporary sediment basins are intended to detain sediment-laden runoff from disturbed
areas long enough for the sediment to settle out. The temporary sediment basin will be
constructed in the location that will later be modified to serve as the post-construction
6
rain garden. Dredge sediment from the basin, as needed to maintain BMP effectiveness,
typically when the design storage volume is no more than one-third filled with sediment.
Inspect the sediment basin embankments for stability and seepage. Inspect the inlet and
outlet of the basin, repair damage, and remove debris. Remove, clean and replace the
gravel around the outlet on a regular basis to remove the accumulated sediment within it
and keep the outlet functioning. Be aware that removal of a sediment basin may require
dewatering and associated permit requirements. Do not remove a sediment basin until the
upstream area has been stabilized with vegetation.
Sediment control logs, inlet protection, and outlet structure protection prevent sediment
from entering storm drainage systems prior to permanent stabilization of the disturbed
site area via ponding and settling of sediment. Sediment control logs or gravel bags shall
be placed at the upstream end and downstream end of new culverts and inlets as well as
existing culverts and inlets near the site as inlet protection. Storm sewer culvert
protection must be inspected and maintained after every rainfall event that produces
runoff. Sediment must be removed and rocks replaced. Gravel bag wattles shall be used
as flow line protection along proposed curb & gutter on the site. Sediment control logs
shall also be implemented as sediment control and velocity reduction in existing and
proposed swales as necessary. Sediment control logs shall be installed immediately upon
completion of over-lot grading and/or the installation of the proposed swales.
Non-Structural Practices: All low sloped areas exposed during land disturbing activity
(stripping, grading, utility installations, stockpiling, filling, etc.) shall be kept in a
roughened condition by ripping or disking along land contours until mulch, vegetation or
other permanent erosion control is installed.
All exposed steep sloped areas exposed during land disturbing activity (stripping,
grading, utility installations, stockpiling, filling, etc.) shall have slope protection. The
contractor shall use a "tracked" vehicle, run perpendicular to slope so that the tracking
runs on the contour to inhibit rill/gully erosion; the contractor may use other windrow-
type methods as necessary.
No soil shall remain exposed by land disturbing activity for more than thirty (30) days.
At that time temporary or permanent erosion control seed/mulch, landscaping, etc. is
required.
7
Additional Non-Structural Practices are strongly encouraged such as minimizing the
disturbance of soils and vegetation, providing educational materials on disposal
/recycling, spill prevention / clean up, identification and elimination of illicit discharges,
promotion of street sweeping and the development of public education programs.
THE CONTRACTOR SHALL ADD ANY AND ALL BMP’S AND DETAILS
NEEDED FOR SEDIMENT/EROSION CONTROL.
8
3.2 Materials Handling and Spill Prevention
Potential impacts from significant materials and their handling are as follows:
Chemicals, cleaning substances, and petroleum products related to the construction will
be stored within the construction trailer or storage shed where it will not be in contact
with precipitation. No storage of these materials will be allowed outside.
Fueling and maintenance of equipment shall take place at the construction staging area.
Fueling will be accomplished with fueling trucks on an as needed basis. Absorbent (kitty
litter) will be in the construction trailer and applied on any spill immediately and the dry
material disposed of properly and legally.
All construction waste shall be disposed of in the available dumpsters throughout the
workday. Liquid wastes will be hauled off site and disposed of properly and legally.
Any cleaning or maintenance of small equipment will be required to be done within a
containment device (horse trough or small “kiddy pool”) and the liquid disposed of
properly and legally.
In the event of any spill, the SWMP Administrator shall be immediately notified.
Spills can be broken into three categories. Their definitions and the procedures required
to address the spills are as follow:
Minor Spill – A spill generally of less than 5 gallons which is unlikely to reach adjacent
waters (i.e. equipment leak).
Procedure:
a. Stop the source of the spill.
b. Contain the spillage.
c. Contact the SWMP Administrator.
d. Clean up the spill with on-site absorbent material (kitty litter)
e. Dispose of the dry material properly or legally.
f. Document the spill and the response in the SWMP including dates
and times – verify that the pollutants are completely cleaned up.
g. Include incident in the following training meeting.
h. Provide information to the City of Fort Collins at the next regular
inspection.
9
Significant Spill – A spill of pollutants or oils of any size that will likely or has reached
adjacent waters, may endanger health or the environment, or which may exceed a water
quality standard.
Procedure:
a. Stop the source of the spill.
b. Contain the spillage.
c. Contact the SWMP Administrator.
d. Clean up the spill with on-site absorbent material (kitty litter)
e. Dispose of the dry material properly or legally.
f. Document the spill and the response in the SWMP – verify that the
pollutants are completely cleaned up.
g. Notify the City of Fort Collins (970) 221-6700 and the Colorado
Department of Public Health and Environment spill reporting line
(877) 518-5608 of the spill.
h. Notify the same two entities above with a written submission
(outlined within the permit) within 5 calendar days.
i. Include incident in the following training meeting.
Hazardous Spill – A spill of a dangerous substance requiring expert cleanup.
Procedure:
a. Secure the area – do not approach the spill.
b. Offer first aid to any injured parties.
c. Call 911 and describe the nature of the spill and any injuries.
d. If possible, isolate downstream areas from the spill (for example,
cover an inlet that is downstream and a safe distance from the spill
with plastic and soil).
e. Contact the SWMP Administrator.
f. Document the spill and the response in the SWMP
g. Notify the City of Fort Collins (970) 221-6700 and the Colorado
Department of Public Health and Environment spill reporting line
(877) 518-5608 of the spill.
h. Notify the same two entities above with a written submission
(outlined within the permit) within 5 calendar days.
i. Include incident in the following training meeting.
10
4. STORMWATER MANAGEMENT CONTROLS
4.1. SWMP Administrator
The Local Contact and SWMP Administrator is (INSERT CONTACT NAME,
POSITION, COMPANY, AND PHONE NUMBER).
(INSERT CONTACT) will be responsible for developing, implementing, maintaining,
and revising the SWMP. (INSERT CONTACT) will also be responsible for required
inspections and coordinating and documenting changes or repairs resulting from
inspections. (INSERT CONTACT) will be responsible for the training and enforcement
aspects of the SWMP and he is the first point of contact for any stormwater issues.
4.2. Identification of Potential Pollution Sources
The permit identifies 13 potential sources that must be evaluated for their potential to
contribute pollutants to stormwater discharge. These items have been evaluated below
for this project:
1) Disturbed and stored soil – YES – The construction will require that areas
be disturbed exposing soil including foundation construction, paving and
repaving, slope construction, and utility installation as shown on the plans.
BMPs will include silt fence and sediment control logs or inlet protection
on existing and proposed culverts and inlets, minimizing disturbance of
existing vegetation and hard surfaces, and slope roughening and tracking
of slopes after disturbance and prior to landscaping, paving, or building
will be implemented.
2) Vehicle tracking of sediment – YES – The construction will require that
subgrade be prepared for pavement and that vehicles drive on unpaved
surfaces to the proposed buildings and utility improvement locations.
BMPs will include a policy that vehicles be clean prior to entering the site
and, if they become muddy during construction or earthwork activities,
mud is removed by hand from the vehicle prior to departing the site in an
area near the vehicle tracking pad. Any soil that is tracked from the site is
to be disposed of in the trash dumpster by sweeping or scraping the
material off the street. Any muddy vehicle will use the vehicle tracking
pad prior to leaving the site.
3) Management of contaminated soil – NO – Soil borings do not indicate any
existing contamination.
4) Loading and unloading operations – YES – Chemicals and petroleum
products will be brought to the site. Anytime these are being transported,
they will be in a sealed container.
11
5) Outdoor storage activities – YES – Inert materials such as wood and stone
will be stored outside and will likely be covered with tarps or plastic, but
are not pollutant sources and are not covered by the permit. Chemicals
and petroleum products will be stored within the construction trailer or
storage shed. Cement and mortar bags (if not contained in a vehicle or
storage shed) will be completely covered with plastic to avoid contact with
precipitation.
6) Vehicle and equipment maintenance and fueling – NO – Vehicle
maintenance and fueling will not take place. No fuel will be stored on site.
7) Significant dust or particulate generating processes – YES – Most of the
1.51 acre site will be exposed from the over-lot grading of the project. In
order to control the dust or particulate generating process a water truck
will be on site at all times. The disturbed ground will be watered as
needed to control dust from leaving the site.
8) The area of heavy construction is very limited and none of the operations
are expected to generate significant dust.
9) Routine maintenance activities involving fertilizers, pesticides, detergents,
fuels, solvents, oils, etc. – YES – Fertilizers and pesticides will not be
used. Any cleaning or maintenance of small equipment will be required to
be done within a containment device (horse trough or small “kiddy pool”
and the liquid disposed of properly and legally.
10) On-site waste management – YES – The buildings and site construction
(access drive, concrete walks, underground utilities) will result in
construction waste. A dumpster for trash and a dumpster for bulk
recycling will be on the site. Waste will be hauled to the dumpsters by
hand or in loaders. Dumpsters will be hauled off as needed. No
construction waste will be left outside overnight without being located in a
dumpster. No construction debris (including broken concrete) may be
buried on the site.
11) Concrete truck/equipment washing – YES – A concrete washout will be
provided on site. This will be used for trucks and for any masonry /
concrete tools.
12) Dedicated asphalt of concrete batch plants – NO – None on this project.
13) Non-structural waste sources such as worker trash and portable toilets –
YES –Trash dumpster will be available for worker’s trash and will be
located near the construction trailer and emptied weekly. Portable toilets
will be staked on site near the construction trailer.
14) Other areas where potential spills can occur – NO – The above 12 items
are adequate for the anticipated construction process.
CONTRACTOR TO UPDATE THE ABOVE INFORMATION WITH EXACT LOCATIONS OF THE CONSTRUCTION TRAILER,
VEHICLE TRACKING PAD, CONCRETE WASHOUT, DUMPSTERS, AND PORTABLE TOILETS PRIOR TO COMMENCEMENT OF
CONSTRUCTION AND UPDATED AS NECESSARY THROUGHOUT THE CONSTRUCTION SEQUENCE.
12
5. FINAL STABILIZATION AND LONG TERM STORMWATER
MANAGEMENT
Final stabilization shall be considered achieved once all proposed site improvements are
in place, all vegetation is established as identified on the landscape plan, all temporary
BMPs are removed, and the downstream conveyances are inspected and certified to be
clean and free from any construction debris resulting from the construction. Areas
controlled by grass sod will be considered established upon the completion of the sod
installation. Areas of seeding will be considered established at 70% of original coverage.
After stabilization, there are no other long term, permanent BMPs proposed within the
site other than routine maintenance of the site (landscape mowing, rain garden
maintenance, pavement maintenance, etc.).
6. INSPECTION AND MAINTENANCE
Site inspections will be performed to effectively address maintenance, repair, and
adequacy of BMPs. The site inspections will be performed by the SWMP Administrator
or his designee a minimum of once every fourteen (14) calendar days on active
construction sites and within 24 hours after a significant storm event (event causing
erosion). As part of the site inspections the inspector will keep documentation of all
inspections and BMP maintenance, including updated Site Maps indicating new BMPs or
the removal of BMPs since the previous inspection. Blank Site Maps will be utilized and
will be redlined by the SWMP Administrator throughout construction to note all BMPs,
pollutant sources, storage locations, etc.
Any maintenance, repair, or necessary installation of BMPs that are noted during the
inspection must begin immediately. The modifications shall be noted in the SWMP and
the action taken as a result of the inspection shall be noted and certified on or attached to
the original inspection report (date and time that the repair or change was started and
finished and a certification that it was done properly).
6.1. City of Fort Collins Standard Erosion and Sediment Control Notes
1) The City Stormwater Department erosion control inspector must be notified at
least 24 hours prior to any construction on this site.
13
2) All required BMPs shall be installed prior to any land disturbing activity
(stockpiling, stripping, grading, etc.). All of their required erosion control
measures shall be installed at the appropriate time in the construction sequence as
indicated in the approved project schedule, construction plans, and erosion control
report.
3) Pre-disturbance vegetation shall be protected and retained wherever possible.
Removal or disturbance of existing vegetation shall be limited to the area required
for immediate construction operations, and for the shortest practical period of
time.
4) All soils exposed during land disturbing activity (stripping, grading, utility
installations, stockpiling, filling, etc.) shall be kept in a roughened condition by
ripping or disking along land contours until mulch, vegetation, or other permanent
erosion control is installed. No soils in areas outside project street rights of way
shall remain exposed by land disturbing activity for more than thirty (30) days
before required temporary or permanent erosion control (e.g. seed/mulch,
landscaping, etc.) is installed, unless otherwise approved by the Stormwater
Department.
5) The property must be watered and maintained at all times during construction
activities so as to prevent wind-caused erosion. All land disturbing activities shall
be immediately discontinued when fugitive dust impacts adjacent properties, as
determined by the City Engineering Department.
6) All temporary (structural) erosion control measures must be inspected and
repaired or reconstructed as necessary after each runoff event and every 14 days in
order to assure continued performance of their intended function. All retained
sediments, particularly those on paved roadway surfaces, shall be removed and
disposed of in a manner and location so as not to cause their release into any
drainage way.
7) No stockpile shall exceed ten (10) feet in height. All soil stockpiles shall be
protected from sediment transport by surface roughening, watering, and perimeter
silt fencing. Any soil stockpile remaining after 30 days shall be seeded and
mulched.
14
8) City Ordinance prohibits the tracking, dropping, or depositing of soils or any other
material onto city streets by or from any vehicle. Any inadvertent deposited
material shall be cleaned immediately by the contractor.
6.2. City of Fort Collins Erosion Control Security Calculations
The cost of erosion control for the site was compared to the cost to reseed the entire site
and the greater cost was used to establish the erosion control escrow amount. The cost to
reseed the site is estimated at $2,265.00. Using a multiplier of 1.5 the erosion control
escrow amount would be $3,397.50. The site erosion control cost is estimated at
$4,798.00. Using a multiplier of 1.5 the erosion control escrow amount would be
$7,197.00. The larger sum of the Erosion Control cost and the Reseeding cost shall be
used for the escrow account. Therefore, the Erosion Control Escrow amount is
$7,197.00. See Table 6.1 for a break-down of the costs associated with seeding and
erosion control.
15
Table 6.1: Erosion Control Cost Estimate
ITEM QUANTITY UNIT COST/UNIT
TOTAL
COST
Silt Fence 237 LF $ 2.00 $ 474.00
Sediment Control Log 32 LF $ 7.00 $ 224.00
Inlet Protection (IP) 5 EA $ 150.00 $ 750.00
Outlet Structure Protection (OSP) 2 EA $ 200.00 $ 400.00
Rock Socks 6 EA $ 75.00 $ 450.00
Concrete Washout 1 EA $ 800.00 $ 800.00
Construction Entrance 1 EA $ 1,500.00 $ 1,500.00
Sedimentation Basin 1 EA $ 200.00 $ 200.00
Subtotal $ 4,798.00
Contingency
(50%) $ 2,399.00
Total $ 7,197.00
CITY RESEEDING COST
Reseed/Mulch 1.51 ACRE $ 1,500.00 $ 2,265.00
Subtotal $ 2,265.00
Contingency
(50%) $ 1,132.50
Total $ 3,397.50
CALCULATED EROSION CONTROL ESCROW AMOUNT $7,197
Note: Minimum Escrow Amount is $3,000
16
7. SWMP IMPLEMENTATION
It is the responsibility of the contractor to operate and maintain all facilities and systems
of treatment and control which are installed to achieve compliance with the conditions of
the permit. This includes effective performance, adequate funding, adequate staffing and
training, etc. (see permit).
All personnel on the construction site who will be in a position to affect or be affected by
the SWMP shall be trained prior to beginning work. These individuals will be given
general orientation information regarding the project and SWMP, shown where the
SWMP is physically located, the SWMP will be explained to them and available for their
review, and the enforcement policy will be reviewed. After this training, a certification
that the employee or subcontractor’s employee is familiar with the document and its
procedures will be signed. Copies of these certifications are included in the Appendix.
Throughout the construction, as a part of a weekly safety meeting, the SWMP will be
reviewed with all attendees and any incidents discussed. All attendees shall be logged.
APPENDIX A—BMP DETAILS
B
APPENDIX B—EROSION CONTROL PLAN AND SITE MAP
C
APPENDIX C—CONSTRUCTION SEQUENCE
(Construction Phases) Mobilization Demolition Grading
Utilities
Installation
Flat work
Installation
Vertical
Installation Landscape Demobilization
Best Management Practices (BMPs)
Structural "Installation"
Silt Fence Barriers*
Contour Furrows (Ripping / Disking)
Sediment Trap / Filter*
Vehicle Tracking Pad*
Flow Barriers (Wattles)*
Inlet protection* Any prior inlets that could use protecting
Rock Bags* Any prior inlets that could use protecting
Terracing
Rip Rap
Collecting Asphalt / Concrete Saw Cutting Waste
*All BMPs to be Removed once Construction is Complete,
with the exception of silt fencing, which shall remain in
place until seeded areas are established.
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.
D
APPENDIX D—SOIL INFORMATION
Soil Map—Larimer County Area, Colorado
(Avondale Cottages)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/5/2014
Page 1 of 3
4482590 4482600 4482610 4482620 4482630 4482640 4482650 4482660
4482590 4482600 4482610 4482620 4482630 4482640 4482650 4482660
492860 492870 492880 492890 492900 492910 492920 492930 492940 492950 492960 492970 492980
492860 492870 492880 492890 492900 492910 492920 492930 492940 492950 492960 492970 492980
40° 29' 40'' N
105° 5' 3'' W
40° 29' 40'' N
105° 4' 58'' W
40° 29' 38'' N
105° 5' 3'' W
40° 29' 38'' N
105° 4' 58'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 25 50 100 150
Feet
0 5 10 20 30
Meters
Map Scale: 1:565 if printed on A landscape (11" x 8.5") sheet.
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: http://websoilsurvey.nrcs.usda.gov
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
Map Unit Legend
Larimer County Area, Colorado (CO644)
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
26 Cushman fine sandy loam, 0 to
3 percent slopes
0.4 32.4%
108 Thedalund loam, 3 to 9 percent
slopes
0.9 67.6%
Totals for Area of Interest 1.4 100.0%
Soil Map—Larimer County Area, Colorado Avondale Cottages
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/5/2014
Page 3 of 3
Hydrologic Soil Group—Larimer County Area, Colorado
(Avondale Cottages)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/5/2014
Page 1 of 4
4482590 4482600 4482610 4482620 4482630 4482640 4482650 4482660
4482590 4482600 4482610 4482620 4482630 4482640 4482650 4482660
492860 492870 492880 492890 492900 492910 492920 492930 492940 492950 492960 492970 492980
492860 492870 492880 492890 492900 492910 492920 492930 492940 492950 492960 492970 492980
40° 29' 40'' N
105° 5' 3'' W
40° 29' 40'' N
105° 4' 58'' W
40° 29' 38'' N
105° 5' 3'' W
40° 29' 38'' N
105° 4' 58'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 25 50 100 150
Feet
0 5 10 20 30
Meters
Map Scale: 1:565 if printed on A landscape (11" x 8.5") sheet.
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: http://websoilsurvey.nrcs.usda.gov
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
Hydrologic Soil Group
Hydrologic Soil Group— Summary by Map Unit — Larimer County Area, Colorado (CO644)
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
26 Cushman fine sandy
loam, 0 to 3 percent
slopes
C 0.4 32.4%
108 Thedalund loam, 3 to 9
percent slopes
C 0.9 67.6%
Totals for Area of Interest 1.4 100.0%
Description
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.
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.
Hydrologic Soil Group—Larimer County Area, Colorado Avondale Cottages
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/5/2014
Page 3 of 4
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Hydrologic Soil Group—Larimer County Area, Colorado Avondale Cottages
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/5/2014
Page 4 of 4
K Factor, Whole Soil—Larimer County Area, Colorado
(Avondale Cottages)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/5/2014
Page 1 of 3
4482590 4482600 4482610 4482620 4482630 4482640 4482650 4482660
4482590 4482600 4482610 4482620 4482630 4482640 4482650 4482660
492860 492870 492880 492890 492900 492910 492920 492930 492940 492950 492960 492970 492980
492860 492870 492880 492890 492900 492910 492920 492930 492940 492950 492960 492970 492980
40° 29' 40'' N
105° 5' 3'' W
40° 29' 40'' N
105° 4' 58'' W
40° 29' 38'' N
105° 5' 3'' W
40° 29' 38'' N
105° 4' 58'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 25 50 100 150
Feet
0 5 10 20 30
Meters
Map Scale: 1:565 if printed on A landscape (11" x 8.5") sheet.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
.02
.05
.10
.15
.17
.20
.24
.28
.32
.37
.43
.49
.55
.64
Not rated or not available
Soil Rating Lines
.02
.05
.10
.15
.17
.20
.24
.28
.32
.37
.43
.49
.55
.64
Not rated or not available
Soil Rating Points
.02
.05
.10
.15
.17
.20
.24
.28
.32
.37
.43
.49
.55
.64
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
K Factor, Whole Soil
K Factor, Whole Soil— Summary by Map Unit — Larimer County Area, Colorado (CO644)
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
26 Cushman fine sandy
loam, 0 to 3 percent
slopes
.24 0.4 32.4%
108 Thedalund loam, 3 to 9
percent slopes
.37 0.9 67.6%
Totals for Area of Interest 1.4 100.0%
Description
Erosion factor K indicates the susceptibility of a soil to sheet and rill erosion by
water. Factor K is one of six factors used in the Universal Soil Loss Equation (USLE)
and the Revised Universal Soil Loss Equation (RUSLE) to predict the average
annual rate of soil loss by sheet and rill erosion in tons per acre per year. The
estimates are based primarily on percentage of silt, sand, and organic matter and
on soil structure and saturated hydraulic conductivity (Ksat). Values of K range from
0.02 to 0.69. Other factors being equal, the higher the value, the more susceptible
the soil is to sheet and rill erosion by water.
"Erosion factor Kw (whole soil)" indicates the erodibility of the whole soil. The
estimates are modified by the presence of rock fragments.
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Layer Options (Horizon Aggregation Method): Surface Layer (Not applicable)
K Factor, Whole Soil—Larimer County Area, Colorado Avondale Cottages
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/5/2014
Page 3 of 3
Wind Erodibility Group—Larimer County Area, Colorado
(Avondale Cottages)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/5/2014
Page 1 of 3
4482590 4482600 4482610 4482620 4482630 4482640 4482650 4482660
4482590 4482600 4482610 4482620 4482630 4482640 4482650 4482660
492860 492870 492880 492890 492900 492910 492920 492930 492940 492950 492960 492970 492980
492860 492870 492880 492890 492900 492910 492920 492930 492940 492950 492960 492970 492980
40° 29' 40'' N
105° 5' 3'' W
40° 29' 40'' N
105° 4' 58'' W
40° 29' 38'' N
105° 5' 3'' W
40° 29' 38'' N
105° 4' 58'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 25 50 100 150
Feet
0 5 10 20 30
Meters
Map Scale: 1:565 if printed on A landscape (11" x 8.5") sheet.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
1
2
3
4
4L
5
6
7
8
Not rated or not available
Soil Rating Lines
1
2
3
4
4L
5
6
7
8
Not rated or not available
Soil Rating Points
1
2
3
4
4L
5
6
7
8
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: http://websoilsurvey.nrcs.usda.gov
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
Wind Erodibility Group
Wind Erodibility Group— Summary by Map Unit — Larimer County Area, Colorado (CO644)
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
26 Cushman fine sandy
loam, 0 to 3 percent
slopes
3 0.4 32.4%
108 Thedalund loam, 3 to 9
percent slopes
4L 0.9 67.6%
Totals for Area of Interest 1.4 100.0%
Description
A wind erodibility group (WEG) consists of soils that have similar properties
affecting their susceptibility to wind erosion in cultivated areas. The soils assigned
to group 1 are the most susceptible to wind erosion, and those assigned to group
8 are the least susceptible.
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Lower
Wind Erodibility Group—Larimer County Area, Colorado Avondale Cottages
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/5/2014
Page 3 of 3
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 8, Dec 23, 2013
Soil map units are labeled (as space allows) for map scales 1:50,000
or larger.
Date(s) aerial images were photographed: Apr 22, 2011—Nov 18,
2011
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.
Wind Erodibility Group—Larimer County Area, Colorado
(Avondale Cottages)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/5/2014
Page 2 of 3
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: http://websoilsurvey.nrcs.usda.gov
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 8, Dec 23, 2013
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Apr 22, 2011—Nov
18, 2011
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.
K Factor, Whole Soil—Larimer County Area, Colorado
(Avondale Cottages)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/5/2014
Page 2 of 3
Survey Area Data: Version 8, Dec 23, 2013
Soil map units are labeled (as space allows) for map scales 1:50,000
or larger.
Date(s) aerial images were photographed: Apr 22, 2011—Nov 18,
2011
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.
Hydrologic Soil Group—Larimer County Area, Colorado
(Avondale Cottages)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/5/2014
Page 2 of 4
the version date(s) listed below.
Soil Survey Area: Larimer County Area, Colorado
Survey Area Data: Version 8, Dec 23, 2013
Soil map units are labeled (as space allows) for map scales 1:50,000
or larger.
Date(s) aerial images were photographed: Apr 22, 2011—Nov 18,
2011
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.
Soil Map—Larimer County Area, Colorado
(Avondale Cottages)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
8/5/2014
Page 2 of 3