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TABLE OF CONTENTS
Title Page
Vicinity Map
Table of Contents
Gulley Duran Subdivision ...................................................................................................... 1
I. INTRODUCTION: ........................................................................................................ 1
II. GENERAL LOCATION AND DESCRIPTION......................................................... 1
A. Property location ........................................................................................................ 1
B. Description of Property .............................................................................................. 1
III. EROSION CONTROL – STORMWATER MANAGEMENT ................................. 1
A. General Concept....................................................................................................... 1
B. Specific Details – Erosion/Sediment Controls ....................................................... 2
C. Potential Sources of Pollution/Materials and Site Management ......................... 3
D. Erosion Control Security Deposit ........................................................................... 6
IV. CONCLUSIONS ............................................................................................................ 7
A. Compliance with Standards ....................................................................................... 7
V. REFERENCES ............................................................................................................... 7
APPENDIX I
Erosion Control Security Deposit Estimate
Erosion Control Plan
Page 1
Erosion Control Report
Gulley Duran Subdivision; Fort Collins, Colorado
I. INTRODUCTION:
1. This report presents the pertinent data used in preparing the erosion control report for
Gulley Duran Subdivision. Proposed grading for the project will not adversely impact
neighboring properties.
II. GENERAL LOCATION AND DESCRIPTION
A. Property location
1. Gulley Duran Subdivision is bounded on the north by Lot 4, Amended Hersh
MRD, owned by the City of Fort Collins. On the south by a single-family
residence property owned by Brandi Herring, on the west by undeveloped
property owned by the Larimer County Board of Commissioners. There is a
single-family residence property owned by Steven Colter northeast of the
subdivision, and a property owned by James Gulley southeast of the
subdivision.
2. Refer to the vicinity map located near the beginning of this report.
B. Description of Property
1. Lot 1, Gulley Duran Subdivision has a total project area of approximately
18.04 acres with the private driveway extension to the east.
2. Lot 1, Gulley Duran Subdivision will consist of a single-family residence,
with a future guest house and future barn.
III. EROSION CONTROL – STORMWATER MANAGEMENT
A. General Concept
1. Erosion control measures and the SWMP Administrator are identified on the
Erosion Control Plan. Standard Grading and Erosion and Sediment Control
Construction Plan Notes are included on the Project Notes Sheet.
2. An erosion control security deposit is required in accordance with City of Fort
Collins policy. In no instance shall the amount of the security be less than
$3,000.00.
Page 2
Erosion Control Report
Gulley Duran Subdivision; Fort Collins, Colorado
3. The site has slight to moderate slopes at toward the south and east and is
vegetated. Prior to dirt work operations, the site vegetation consists primarily
of native and non-native grasses. The total disturbed area will be
approximately 3.11 acres. These grasses naturally grow in clumps, which
inevitably leads to some bare areas. In general, the site has approximately
60% vegetative cover. The majority of the site consists of Heldt Clay Loam
Hydrologic Group C, with moderately high runoff potential. Due to the
vegetative cover and moderate site slopes at 3-6 %, on-site rainfall erodibility
will be negligible. The site consists of a four to six inch vegetative and top
soil layer over sandstone/claystone according to the Geotechnical Subsurface
Exploration Report for the Proposed Gulley Residence; Parcel # 9610400006
by Earth Engineering Company, Inc. titled “Geotechnical Subsurface
Exploration Proposed Gulley Residence”; EEC Project No. 18-01-066; report
dated May 22, 2018.
4. Construction BMP’s will consist of wattles and surface roughening and re-
vegetation around downstream construction limits.
B. Specific Details – Erosion/Sediment Controls
1. The following temporary BMP measures are specified on the Erosion Control
Plan:
a. Wattles are on and off site. Wattle installation shall be installed to
reduce erosion prior to runoff reaching adjacent undisturbed areas.
Wattles shall be installed in general compliance with the installation
detail on the Detail Sheet. Wattles shall be inspected and maintained on
biweekly basis and within twenty-four (24) hours of a storm event.
Wattles shall remain in place until contributing drainage areas are
sufficiently stabilized.
b. Surface roughening shall be completed after final grading to track the
surface running parallel to the contours of the land, to help minimize
wind and water erosion. Surface roughening can also be used to help
establish conditions favorable to establishment of vegetation. Surface
roughening is a temporary measure and shall be completed until the soils
are sufficiently stabilized. Surface roughening shall be inspected and
maintained on biweekly basis and within twenty-four (24) hours of a
storm event, and necessary maintenance shall be completed at that time.
c. Vehicle tracking control of sediments will occur at the northeast
entrance of the site at the proposed driveway as noted below (C. 1. a).
Vehicle tracking control shall be inspected and maintained on biweekly
basis and within twenty-four (24) hours of a storm event, and necessary
maintenance shall be completed at that time.
Page 3
Erosion Control Report
Gulley Duran Subdivision; Fort Collins, Colorado
d. Vehicle and equipment maintenance and fueling will be completed in a
clearly designated on-site fueling and maintenance area that is clean and
dry as noted below (C. 1. f.). Vehicle and equipment maintenance area
shall be inspected after each use and maintenance shall be completed at
that time.
e. Concrete truck/equipment washing, including the concrete truck chute
and associated fixtures and equipment wash out area, will be provided
on site. Washout location is shown on the Erosion Control Plan and the
installation detail is shown on the Detail Sheet. This location is a
suggestion and can be relocated at the discretion of the Contractor while
keeping it away from drainage courses. The concrete washout area
should be inspected regularly. Confirmation that the washout is being
used should be noted to ensure that other undesignated areas of the site
are not being used incorrectly as a concrete washout.
2. The following permanent erosion control measures will be completed:
a. All disturbed areas will be permanently landscaped or permanently
vegetated.
C. Potential Sources of Pollution/Materials and Site Management
1. The following potential sources of pollution have been evaluated:
a. Disturbed and stored soils will be prevented from leaving the site using
wattles and the proposed on-site private driveway. The on-site private
driveway will consist of 4" of compacted road base and will provide
vehicle tracking control. If the private driveway is not installed at the
time of construction, a temporary vehicle tracking control pad shall be
installed and maintained at the driveway access to Lot 1. This temporary
vehicle tracking control will be removed when the driveway has been
installed. Surface roughening shall be completed as noted above (B. 1.
b.) at disturbed and stored soils, to help minimize wind and water
erosion. The installations noted above will help to prevent disturbed and
stored soils from leaving the site and reduce the amount of erosion
materials reaching undisturbed areas.
b. Vehicle tracking control of sediments will occur at the northeast
entrance of the site at the proposed driveway as noted above (C. 1. a).
Vehicle tracking control will reduce the materials reaching the existing
driveway. Frequent scraping and sweeping maintenance and removal of
materials at this location will be required.
Page 4
Erosion Control Report
Gulley Duran Subdivision; Fort Collins, Colorado
c. Spills shall be contained and cleaned up as soon as possible and are the
Contractor’s responsibility. If a spill occurs, absorbent materials could
be used to contain spills and clean the area of residuals. Excavation of
contaminated soils could also be a method of containment. Proper
disposal of the contaminated material at an accepted waste site is the
Contractor’s responsibility. Spills shall not be washed down into
undisturbed areas or buried anywhere. A notification procedure must be
put in place by the Contractor, by which workers would first notify the
site construction superintendent, who would notify the SWMP
Administrator.
Depending on the severity of the spill, the site construction
superintendent and SWMP Administrator would possibly notify the
Colorado Department of Public Health and Environment - Water
Quality Control Division, downstream water users, or other appropriate
agencies. All spills that require cleanup, even if the spill is minor and
does not need to be reported to the state, should still be reported to the
City of Fort Collins Utilities office at erosion@fcgov.com. Pre-existing
contaminated soils are not anticipated.
d. Loading and unloading operations shall be completed in such a way that
does not contribute pollutants to runoff. As site development and
building construction progresses, access to the site will be limited to one
location at the northeast corner of the site. The contractor will be
responsible for the proper handling and management of pollution
sources during loading and unloading.
e. Outdoor storage activities will not include fertilizers or chemicals
including foam insulation or concrete form oil. If building materials are
stored on site, they must be stored in such a way that they do not
contribute pollutants to runoff. Building materials shall be stored in
weather proof containers.
f. Vehicle and equipment maintenance and fueling will be completed in a
clearly designated on-site fueling and maintenance area that is clean and
dry. Employees and subcontractors shall be trained in proper handling
and storage practices. If fuel tanks are stored on-site leak proof
secondary containment shall be provided. Primary and secondary
storage containers shall be regularly inspected for leaks, corrosion,
support or foundation failure, or other signs of deterioration and tested
for soundness. Other Secondary containment measures could be used to
prevent a spill from spreading across the site and may include dikes,
berms, curbing, or other containment methods. Proper disposal of
contaminated materials shall be completed as noted above (C. 1. c.).
Page 5
Erosion Control Report
Gulley Duran Subdivision; Fort Collins, Colorado
g. Best Management Practices to Control Dust:
(a) Required Best Management Practices: Any person, owner, or
operator who conducts earthmoving that is a dust generating
activity or source shall implement the following best
management practices to prevent off-property transport of
fugitive dust emissions:
(i) Minimize disturbed area: plan the project or activity so that
the minimum amount of disturbed soil or surface area is
exposed to wind or vehicle traffic at any one time.
(ii) Reduce vehicle speeds: establish a maximum speed limit or
install traffic calming devices to reduce speeds to a rate to
mitigate off-property transport of dust entrained by vehicles.
(iii) Minimize drop height: Drivers and operators shall unload
truck beds and loader or excavator buckets slowly, and
minimize drop height of materials to the lowest height
possible, including screening operations.
(iv) High winds restriction: temporarily halt work activities
during high wind events greater than 30 mph if operations
would result in off-property transport.
(v) Restrict access: restrict access to the work area to only
authorized vehicles and personnel.
(b) In the event that the Best Management Practices noted with (C.
1. g. (a)) are ineffective to prevent off-property transport, the
person, owner, or operator shall use at least one of the following
best management practices:
(i) Wet suppression: apply water to disturbed soil surfaces,
backfill materials, screenings, and other dust generating
operations as necessary and appropriate, considering current
weather conditions, and prevent water used for dust control
from entering any public right-of-way, stormwater drainage
facility, or watercourse.
(ii) Surface roughening: shall be completed as noted above (B.
1. b.) at disturbed and stored soils, to help minimize wind
erosion.
Page 6
Erosion Control Report
Gulley Duran Subdivision; Fort Collins, Colorado
h. Routine maintenance activities involving fertilizers, pesticides,
detergents, fuels, solvents, oils, ect. will be completed in a clearly
designated on-site fueling and maintenance area that is clean and dry as
noted above (C. 1. f.). Vehicle and equipment maintenance area shall be
inspected after each use and maintenance shall be completed at that
time.
i. On-site waste management practices shall be in compliance with the
City Ordinance and Colorado Discharge Permit System requirements.
A dumpster will be used to help eliminate waste from leaving the site.
The dumpster shall be placed away from drainage areas and shall be
leak proof and covered when needed. The Developer shall at all times
take whatever measures are necessary to assure that proper containment
and disposal of pollutants on the site are in accordance with any and all
local, state and federal regulations.
j. Concrete truck/equipment washing, including the concrete truck chute
and associated fixtures and equipment wash out area, will be provided
on site. Washout location is shown on the Erosion Control Plan and the
installation detail is shown on the Detail Sheet. This location is a
suggestion and can be relocated at the discretion of the Contractor while
keeping it away from drainage courses. The concrete washout area
should be inspected regularly. Confirmation that the washout is being
used should be noted to ensure that other undesignated areas of the site
are not being used incorrectly as a concrete washout.
k. Dedicated asphalt and concrete batch plants are not included with this
project.
l. Non-industrial waste sources generated by construction and worker
trash shall be accommodated by an on-site dumpster. It shall be the
responsibility of the Contractor to maintain a clean job site as to prevent
dispersion of waste material and potential pollutants into adjacent
properties or waterways. Portable toilets shall be placed on dirt and
staked or otherwise secured in a way that does not allow for it to tip and
discharge materials. Locate portable toilets far from drainage courses.
D. Erosion Control Security Deposit
1. An erosion control security deposit is required in accordance with City of Fort
Collins policy. In no instance shall the amount of the security be less than
$3,000.00.
2. See the Erosion Control Security Deposit Requirements document located in
Appendix I.
Page 7
Erosion Control Report
Gulley Duran Subdivision; Fort Collins, Colorado
3. The erosion control security deposit is reimbursable upon reaching final
stabilization and no security had to be used to ensure the site prevents
materials including sediment from leaving the site.
4. The erosion control security deposit is equal to $12,288.38.
5. Final stabilization will be achieved and all disturbed on-site areas not
including the driveway will be permanently landscaped or permanently
vegetated. Areas not permanently landscaped or permanently vegetated will
be seeded. As defined by the Colorado Department of Public Health and
Environment, “Final Stabilization is reached when all soil disturbing
activities at the site have been completed and uniform vegetative cover has
been established with a density of at least 70 percent of pre-disturbance levels
or equivalent permanent erosion reduction methods have been employed”.
City of Fort Collins requires 70 percent vegetative density.
IV. CONCLUSIONS
A. Compliance with Standards
1. The erosion control measures for Gulley Duran Subdivision will comply with
the requirements of the City of Fort Collins Storm Drainage Design Criteria
Manual.
2. Final stabilization of the site shall be achieved based on the Landscape Plan
by Kenney Lee architecture group, inc. All disturbed areas will be
permanently landscaped or permanently vegetated. Reference the Landscape
Plan for soil preparation, native seed notes for crimping needs and dryland
native seed mix.
V. REFERENCES
A. City of Fort Collins “Storm Drainage Design Criteria and Construction Standards”;
December 2011
B. Urban Storm Drainage Criteria Manual Volume 1; Urban Drainage and Flood
Control District, Denver, Colorado, June, 2001.
C. Urban Storm Drainage Criteria Manual Volume 2; Urban Drainage and Flood
Control District, Denver, Colorado, June, 2001.
D. Urban Storm Drainage Criteria Manual Volume 3, Best Management Practices;
Urban Drainage and Flood Control District, Denver, Colorado, August, 2011.
APPENDIX I
Erosion Control Security Deposit Estimate
Erosion Control Plan
Project: Disturbed Acres: 3.11
EROSION CONTROL BMPs Units
Estimated
Quantity
Unit
Price
Total
Price
EA. 1 $825.00 $825.00
LF 1,979 $2.75 $5,442.25
EA. 1 $1,925.00 $1,925.00
Sub-Total: $8,192.25
1.5 x Sub-Total: $12,288.38
Amount of security: $12,288.38
Total Acres x Price/acre: 3047.8
$980.00 Sub-Total: $3,047.80
1.5 x Sub-Total: $4,571.70
Amount to Re-seed: $4,571.70
Minimum escrow amount: $3,000.00
Erosion Control Escrow: $12,288.38
Fields in yellow should be amended for this project.
Erosion and Sediment Control Escrow/Security Calculation
for The City of Fort Collins
Gulley Duran Subdivision; Fort Collins, Colorado
BMP Amount
Concrete Washout (CW)
Wattle (W)
“The amount of the security must be based on one and one-half times the estimate of the cost to install the approved measures, or one and one-half times
the cost to re-vegetate the disturbed land to dry land grasses based upon unit cost determined by the City's Annual Revegetation and Stabilization Bid,
whichever is greater. In no instance, will the amount of security be less than one thousand five hundred dollars ($1,500) for residential development or three
thousand dollars ($3,000) for commercial development”
Vehicle Tracking Control (VTC)
Reseeding
Unit Price of Seeding per acre:
Minimum Escrow Amount
Final Escrow Amount
11/2/\\2018 SERVER\10:Clients\06 G-AM Clients\Gulley Beth\3000-01-18 Gulley Duran Subdivision Fort Collins\Documents\Erosion Control\FDP Submittal 2 (BRB)\Report Revs based on 10-24-2018
Comments (BRB)\Gulley Escrow