HomeMy WebLinkAboutFORT COLLINS JEEP - FDP - FDP170035 - SUBMITTAL DOCUMENTS - ROUND 1 - EROSION CONTROL LETTER/REPORTEROSION AND SEDIMENT CONTROL
ASSOCIATED WITH CONSTRUCTION ACTIVITIES
FOR
FORT COLLINS JEEP DEALERSHIP
CITY OF FORT COLLINS, COLORADO
November 3, 2017
Job No. 16-018
Prepared for:
COMMERCIAL BUILDING SERVICES
7561 South Grant Street
Littleton, CO 80120
Prepared by:
PARAGON ENGINEERING CONSULTANTS, INC.
7852 S. Elati, Suite 203
Littleton, CO 80120
303-794-8604
Attn: Wendell Ayers, President
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EROSION AND SEDIMENT CONTROL NARRATIVE REPORT
Name, address and telephone number
Owner: Steve More
Commercial Building Services
7651 S. Grant Street Suite A-4
Littleton, CO 80122
303-730-3001
steve@cbsconstruction.com
Erosion Control Consultant: Paragon Engineering Consultants, Inc.
7852 S Elati, Suite 106
Littleton, CO 80120
Attn: Troy Denning, PE
303-794-8604
Current Developed Conditions
The project consists of the re-development of an approximately 4.4-parcel with from former
lumber yard to proposed car dealership. The site is located in the Southeast ¼ of Section 35,
Township 7 North, Range 69 West of the 5th Principal Meridian., County of Larimer, State of
Colorado. A Vicinity Map is contained within Appendix A.
This site resides in the drainage basin for Fossil Creek (approximately ¾ of a mile southeast),
which is ultimately tributary to Cache La Poudre River (5 miles east). Runoff from the site
drains off-site to the east to South Mason Street and to the south to West Harmony Road,
where it flows via street gutters towards the intersection of the two streets and enters the
city storm sewer via a 10’ Type R Inlet.
The existing site is 19% vegetated, with approximately 80% coverage in these areas. The
vegetation consists of mature landscaping consisting of landscaped grass areas with trees and
shrubs. The existing slopes within the parking area range from 1-2%, while the perimeter
landscape areas along S. Mason St. and W Harmony Road range up to 3-4%. Soils on the site,
according to USDA National Soil Conservation website, consist of Nunn clay loam – Hydrologic
Soil Type C (94% of site) with a small area of Altvan-Satanta loams (6%) – Hydrologic Soil Type
B, in the northeast corner of the site. When exposed, these fine-grained soils will be prone to
sediment transport and channel cutting during storm events, but low slopes on site will
mitigate major erosion events.
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Nature and Purpose of Construction
This project involves the remodeling of the existing main building on the site, with two
additions and one removed area at the building, the removal and replacement of
deteriorated asphalt paving and concrete areas from the parking area of the site. Alterations
will be made to the two existing entrances to the site, and new areas of landscape will be
incorporated into the parking lot and around the building.
Approximately 4.0 acres may be disturbed during the redevelopment of this project.
Rainfall Erodibility & Erosion and Sediment Control Methods
According to the NRCS Soil Survey, the soils on the site are predominantly Nunn clay loam,
(94.2%) and the remainder Altvan-Satanta loams (5.8%).
Nunn clay loam is a fine clay loam that is hard, very friable, sticky and plastic. The cohesive
properties and low slopes on site indicate this material will have a low erodibility.
The Altvan-Satanta loam is fine sandy loam with fine pebbles. This material is not cohesive
and also fine, which will lend itself to sediment transport during storm events. The area
composed of this material is limited to a small area in the northeast corner of the site. The
sediment control BMPs, silt fence, and rock berms in this area of the site must be specifically
monitored for maintenance issues.
The erosion control measures for the site are shown on the attached erosion control
drawing. The NRCS Soil Survey report is included in Appendix A.
Prior to Construction:
Silt fence shall typically be installed down-slope of any proposed improvements, as Silt fence
shall also be installed around any stockpiles kept on site. Construction fence will be added to
the west side of the site.
Potential Pollution Sources
The Fort Collins Stormwater Criteria Manual identifies potential sources of pollution, listed
on Table 1, for which at a minimum must be identified in the Erosion Control Report. Table 1
provides information regarding the specific potential pollution sources identified for this site.
The table also provides the activities associated with these sources and BMPs selected to
control contaminants from these sources from leaving the site in stormwater runoff. Specific
details regarding BMP selection, implementation, inspection and maintenance are provided
in the Stormwater Management Controls (SWMC) section, below. These sources should be
updated as the project progresses. Additional pollution sources that are not included on this
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table should be added and delete sources that are no longer used on site. Handwritten
changes are acceptable, date and initial changes that are made.
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Table 1
Potential Pollution Sources
Potential pollution source
Potential with
this project
Activities associated with this
pollution source BMPs selected to control source*
Approximate location of pollution
source on site**
All disturbed and stored soils
(includes stockpiles)
Yes Clearing and grubbing, grading,
utility installation, building
construction, final stabilization
Silt fence, inlet protection, vehicle tracking
control, construction fencing, surface
roughening, stabilized staging area,
seeding/mulching, and street cleaning
All disturbed areas of the site except
paved surfaces
Vehicle tracking of sediments Yes Clearing and grubbing, grading,
utility installation, building
construction, final stabilization
Silt fence, inlet protection, vehicle tracking
control, construction fencing, surface
roughening, stabilized staging area,
seeding/mulching, and street cleaning
At site access point, which is limited
to the north east entrance.
Management of contaminated
soils
No No known contaminated soils exist
on site.
If contaminated soils are encountered, all
activity shall be stopped until the situation
can be assessed. The Superintendent will
be contacted for further direction. Affected
soils should be isolated from clean soils
(placed on and covered with plastic, or
placed in 55-gallon drums) whenever
possible until a remediation plan can be
implemented.
Not applicable
Loading and unloading
operations
Yes Delivery and staging of materials Vehicle tracking control, construction
fencing, and stabilized staging area.
Stabilized staging area
Outdoor storage activities
(including building materials,
fertilizers, chemicals, etc.)
Yes Delivery and staging of materials Stabilized staging area and street cleaning.
Secondary containment ditches around
storage areas.
Provide and maintain spill control
materials specified by chemical
manufacturers (e.g. absorbents, sand)
Stabilized staging area – only those
products needed for use on the site
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Table 1
Potential Pollution Sources
Potential pollution source
Potential with
this project
Activities associated with this
pollution source BMPs selected to control source*
Approximate location of pollution
source on site**
Routine maintenance activities
involving fertilizers,
pesticides, detergents, fuels,
paints, solvents, oils, grease,
glues, joint compound, etc.
Yes Vehicle and equipment use and
storage, utility installation, final
stabilization
Stabilized staging area and street cleaning.
Individual waste containment systems –
such as children’s rigid pools, buckets,
drums or other water tight vessel.
Secondary containment ditches around
storage areas.
Provide and maintain spill control
materials specified by chemical
manufacturers (e.g. absorbents, sand)
These items are generally kept in
subcontractor vehicles or within the
structure once constructed – only
those products needed for use on the
site will be on site at any one time.
Extra product not used on site will be
removed from the site by the
subcontractor.
On-site waste management
practices (waste piles, liquid
wastes, dumpsters, etc.)
Yes Clearing and grubbing, grading,
utility installation, building
construction, final stabilization
Dumpsters including regular trash removal,
site management practices. Liquid wastes
will be contained and removed from site
and properly disposed by subcontractors
generating such wastes. Dumpsters will be
emptied by the appropriate subcontractor
for disposal at a designated off-site
disposal facility.
Dumpsters will be placed on the site
in amounts needed for anticipated
waste generation. Waste piles that are
unable to be transferred to available
dumpsters on site will be removed
from site and transported to
designated off-site disposal facilities.
Concrete truck/equipment
washing, including the
concrete truck chute and
associated fixtures and
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Table 1
Potential Pollution Sources
Potential pollution source
Potential with
this project
Activities associated with this
pollution source BMPs selected to control source*
Approximate location of pollution
source on site**
* See further discussion of appropriate BMPs in Stormwater Management Controls (SWMC) and Appendix B.
** For specific location of BMPs used on site see construction documents.
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Stormwater Management Controls (SWMC)
Silt fence is a sediment-trapping device installed prior to beginning earthwork activities. Silt
fences will be installed inside the property boundary and at sensitive locations. The silt
fence along the property boundaries shall remain in place until permanent vegetation has
been established.
A construction entrance with a vehicle tracking control pad will be provided at the proposed
northeast access drive off existing S. Mason St.
A stabilized staging area (SSA) will be constructed near the construction entrance to the
northwest. The SSA will be used for storing construction materials, equipment and vehicles.
Drip pans, cardboard, plywood or other absorbent materials must be placed beneath parked
vehicles to control the release of hazardous materials from the SSA. Hazardous materials
include but are not limited to gasoline, motor oil, hydraulic oil, and anti-freeze.
The existing 10-foot inlet at the intersection of S. Mason St. and W. Harmony Drive (on S.
Mason St.) shall be protected with inlet protection. Rock socks shall be installed along S.
Mason St, and W. Harmony Rd, as allowed.
All storm sewer inlets made operable during construction will have sediment-entrapment
facilities installed to prevent sediment-laden runoff from entering the inlet. Contractor shall
install the most effective method of inlet protection for the site conditions.
Rock socks are constructed of gravel that has been wrapped by wire mesh or a geotextile to
form an elongated cylindrical filter. They are used for perimeter protection (street flowlines,
especially) or as part of inlet protection.
A concrete washout shall be installed before any concrete mixing is done, and located near
the SSA.
A portable concrete washout consists of a shallow container that is designed to capture
waste water and waste products resulting from the cleaning of concrete and masonry
equipment. They are used to contain concrete and liquids from chutes of concrete mixers
and hoppers that are rinsed out after delivery. The washout consolidates solids and allows
for evaporation of liquids for easier disposal and to prevent runoff into storm sewers or
waters on the site. The washout area shall be located near the SSA to control tracking of
mud.
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Dryland Vegetation
Dryland vegetation construction is to be limited to small landscape areas newly created. If
final landscape stabilization is delayed more than thirty days, temporary seeding and
mulching for the establishment of stabilizing grasses shall be performed. Ultimately all
landscape areas will be planted with landscape plants. Areas of sod disturbed in construction
to be repaired.
Refer to “L-1 Landscape Plan” from the “Fort Collins Jeep Dealership – Project Development
Plan” set for sod, final vegetation, and soil amendment requirements associated with Fort
Collins Municipal Code Sec. 12-130 through 12-132.
Temporary and permanent seeding and mulching shall be performed according to the
“Temporary and Permanent Seeding (TS/PS) EC-2” specification sheet, included in Appendix B
of this report.
Sequence of Construction Activities
The construction schedule is as follows:
Table 2
Construction Schedule
Construction Activity Control Measures Timeline
Mobilization
Install construction entrance, vehicle
tracking control, stabilized staging area, silt
fence, inlet protection, and rock socks
Spring 2017
Demolition
Maintain and replace control measures as
necessary to ensure proper operation.
Specifically, but not limited to, replace damaged
silt fence sections, clear inlet protection and silt
fence of sediment and debris, maintain vehicle
tracking control and stabilized staging area, and
monitor seeding and mulching.
Spring 2017
Site grading
Seed and mulch all exposed soil areas. Control
measure construction shall be ongoing as
grading operations proceed; use on newly
formed landscape areas if final landscape
installation is delayed more than 30 days
Summer 2017
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Construction Activity Control Measures Timeline
Building re-model Install concrete washout area
Ongoing
(refer to
construction
drawings)
Paving and landscaping
Maintain and replace control measures as
necessary to ensure proper operation.
Specifically, but not limited to, replace damaged
silt fence sections, clear inlet protection and silt
fence of sediment and debris, maintain vehicle
tracking control and stabilized staging area, and
monitor seeding and mulching.
Ongoing
(refer to
construction
drawings)
De-mobilization Remove erosion control measures Winter 2018
Note: 1. Dates are approximate, assuming good weather and no unforeseen circumstances.
2. Refer to project schedule maintained by site superintendent for timelines and specific dates for all
construction tasks.
Maintenance
The contractor shall make a thorough inspection of their stormwater management system at
least once every 14 days and after any precipitation or snowmelt event that causes surface
erosion.
The construction site perimeter, disturbed areas, and areas used for materials storage that
are exposed to precipitation shall be inspected for evidence of, or the potential for,
pollutants entering the drainage system. Erosion and sediment control measures identified
in the erosion control plan or SWMP shall be observed to ensure that they are operating
correctly.
Based on the results of the inspection, the description of potential pollution sources, and the
pollution prevention and control measures that are identified in the erosion control plan or
SWMP shall be revised and modified as appropriate as soon as practicable after such
inspection. Modifications to control measures shall be implemented in a timely manner, but
in no case more than 7 calendar days after the inspection.
The operator shall keep a record of inspections. Any incidence of non-compliance, such as
uncontrolled releases of mud or muddy water of measurable quantities of sediment found
off the site, shall be recorded with a brief explanation as to the measures taken to prevent
future violations, as well as any measure taken to clean up the sediment that has left the site.
After adequate measures have been taken to correct any problems, or where a report does
not identify any incidents of non-compliance, the report shall contain a signed certification
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indicating that the site is in compliance. This record shall be made available to the Division
upon request.
In addition to the above, the following maintenance requirements shall be used for individual
BMPs.
Mulching - The key consideration is that the mulch needs to last long enough to
achieve its erosion control objectives. Reapplication of mulch may be required to
maintain effective soil stabilization over disturbed areas and slopes. After any rainfall
event, the Contractor is responsible for maintaining all slopes to prevent erosion.
Vehicle Tracking Control - Inspect routinely for damage and assess the effectiveness
of the BMP. Remove aggregate, separate and dispose of sediment if construction
entrance/exit is clogged with sediment. Inspect for damage and repair as needed.
Silt Fence - Inspect silt fence at least once every 14 days and after rainfall events.
Sediment shall be removed when the buildup reaches one third the height of the
fence. Fence that has been damaged or washed-out shall be repaired or replaced in-
kind.
Inlet Protection - Inspect at least once every 14 days and after rainfall events. Inspect
rock socks for displacement of the rock contents and/or damage to the surrounding
fabric. Repair fabric and replace as needed.
Geotextiles, Plastic Covers, & Erosion Control Blankets/Mats - These temporary
controls shall be installed per the manufacturer specifications and inspected at least
once every 14 days and after rainfall events to ensure their proper functioning. If
washout or breakage occurs, re-install the material after repairing the damage to the
slope or channel.
APPENDIX A
MAPS AND SOILS INFORMATION
APPENDIX B
EROSION CONTROL DETAILS
APPENDIX C
EROSION CONTROL ESCROW ESTIMATE
Project:
EROSION CONTROL BMPs Units
Estimated
Quantity
Unit
Price
Total
Price
L.F. 1228 $2.50 $3,070.00
EA 7 $200.00 $1,400.00
EA 1 $500.00 $500.00
L.F. 120 $3.00 $360.00
EA 1 $2,400.00 $2,400.00
SY 200 $3.00 $600.00
Sub-Total: $7,730.00
1.5 x Sub-Total: $11,595.00
Amount of security: $11,595.00
Seeding and Mulching Area (Acres): 4.2 Total Acres x Price/acre: $1,680.00
Unit Price of Seeding per acre: $400.00 Sub-Total: $1,680.00
1.5 x Sub-Total: $2,520.00
Amount to Re-seed: $2,520.00
Minimum escrow amount: $3,000.00
Erosion Control Escrow: $11,595.00
Erosion and Sediment Control Escrow/Security Calculation for
The City of Fort Collins
BMP Amount
Silt Fence (SF)
Vehicle Tracking Control (VTC)
Reseeding Amount
Stabilized Staging Area (SSA)
Rock Sock (RS)
Miniumum Escrow Amount
Fort Collins Jeep Dealership Project
“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”
Inlet Protection (IP)
Concrete Washout (CW)
(add all other BMPs for the site in this list)
Final Escrow Amount
11/3/2017 4:30 PM F:\Jobs\2016 Projects\16-018 Fort Collins Jeep\Engineering\Reports\Erosion Control Report\Erosion and Sediment Control Escrow Security Calculation.xls
equipment (includes concrete
and curing compounds)
Yes Foundation construction and flat
work
Concrete washout areas, vehicle tracking
control, and site management practices.
A portable concrete wash out will
provided and will be noted on the
map. Concrete washout areas may be
moved as needed to accommodate
construction schedules.
Dedicated asphalt and
concrete batch plants
No None planned for this site N/A Not applicable for this site.
Non-industrial waste sources
such as worker trash and
portable toilets
Yes All activities Dumpsters with lids, portable toilets
secured to ground, site management
practices. Individual units will be emptied
and their contents properly disposed at off-
site disposal facilities.
Dumpsters and portable toilets will be
placed on the site in amounts needed
for anticipated waste generation.
Their exact locations will be noted on
the site map.
Other areas or procedures
where potential spills can
occur
No No other sources identified at this
time
N/A Not applicable for this site.
Add additional detail to above categories if needed.
will be on site at any one time. Extra
product not used on site will be
removed from the site by the
subcontractor.
Vehicle and equipment
maintenance and fueling
Yes Fueling and equipment repair for
vehicles or equipment used in all
phases of construction activity.
Fueling will be performed by delivery
vehicles which will provide necessary spill
prevention or will be performed off-site.
Fuel, greases and other maintenance
fluids will be used and removed from
site by the subcontractors. During
fueling or maintenance operations
items will be kept on mobile vehicles
and not stored on site.
Significant dust or particulate
generating processes
Yes Clearing and grubbing, grading,
utility installation, building
construction, final stabilization
Wetting of soils.
Refer to City of Fort Collins Odinance No.
44, 2016 “Fugitive Dust Ordinance”.
Municipal Code Sec. 12-153.
All disturbed areas of the site except
paved surfaces.