HomeMy WebLinkAboutTHE GREEN SOLUTION - PDP/FDP - FDP150045 - SUBMITTAL DOCUMENTS - ROUND 2 - STORMWATER MANAGEMENT PLANSTORMWATER MANAGEMENT PLAN
FOR
THE GREEN SOLUTION
FORT COLLINS, COLORADO
February 1, 2016
Prepared for:
TGS Management
700 17th Street, Suite 1610
Denver, CO 80202
Prepared by:
Manhard Consulting
8008 E. Arapahoe Ct., Suite 110
Centennial, CO 80112
Phone: 303.708.0500
ENGINEER’S CERTIFICATION
This report for the construction activities stormwater plan for TGS Management, The Green
Solution, Fort Collins, CO was prepared by me (or under my supervision) in accordance with the
provisions of the State of Colorado Department of Public Health and Environment and Urban
Drainage and Flood Control District, Urban Storm Drainage Criteria Manual, and was designed
to comply with the provisions thereof. I understand that the City of Fort Collins does not, and will
not, assume liability for drainage facilities designed by others.
___________________________
Daniel Madruga
State of Colorado
No. 36834
Date _______________________
OWNERS CERTIFICATION
This Construction Activities Stormwater Management Plan has been submitted as the
application for a Construction Activities Stormwater Discharge Permit filed with the City of Fort
Collins. I understand that additional erosion control, sediment control and water quality
enhancing measures may be required of the owner and his or her agents due to unforeseen
pollutant discharges or if the submitted plan does not function as intended. The requirements of
this plan shall be the obligation of the land owner and/or his successors or heirs; until such time
as the plan is properly completed, modified, or voided.
_______________________________________ Date____________________
Owner or Authorized Agent
_______________________________________
Representing
SWMP ADMINISTRATOR
This Construction Activities Stormwater Management Plan has been submitted as the
application for a Construction Activities Stormwater Discharge Permit filed with the State of
Colorado. I understand that, as SWMP Administrator, I am responsible for developing,
implementing, maintaining and revising the SWMP due to unforeseen pollutant discharges or if
the submitted plan does not function as intended.”
_______________________________________ Date____________________
SWMP Administrator
_______________________________________
Representing
_______________________________________ Date____________________
SWMP Administrator Alternate
_______________________________________
Representing
Page I
TABLE OF CONTENTS
INTRODUCTION ........................................................................................ 1
Site Location .......................................................................................................................... 2
Current Developed Conditions ............................................................................................... 2
Nature and Purpose of Construction ...................................................................................... 2
STORMWATER MANAGEMENT PLAN .................................................... 3
Part I.C.1 – Site Description ................................................................................................... 3
Part I.C.2 – Site Map .............................................................................................................. 4
Part I.C.3 – Stormwater Management Controls ...................................................................... 4
Part I.C.4 – Final Stabilization and Long-term Stormwater Management ...............................10
Part I.C.5 – Inspection and Maintenance ...............................................................................11
CONCLUSION .......................................................................................... 13
Compliance with Standards ...................................................................................................13
Drainage Concept .................................................................................................................13
Sediment and Erosion Control Concept ................................................................................13
REFERENCES ......................................................................................... 14
Page II
Index of Figures
All figures are presented in the appendices
Appendix A
Vicinity Map
Soils Map
Appendix B
Site Maps – Erosion Control Plan
Appendix C
Sequence Schedule
Appendix D
Erosion Control Details
Appendix E
Erosion Control Security Calculations
Appendix F
Spill Report Form
Page 1
INTRODUCTION
This report presents The Green Solution Erosion and Sediment Control Plan (ESCP). The
design and analysis of this site has been performed in accordance with Urban Drainage and
Flood Control District, Urban Storm Drainage Criteria Manual, Volume 3, November 2010,
Colorado Department of Public Health and Environment (CDPHE), and Fort Collins Stormwater
Criteria Manual.
This SWMP includes the elements necessary to comply with the General Permit for construction
activities administered by the U.S. Environmental Protection Agency (EPA) under the Colorado
Discharge Permit System, (CDPS), and all local governing agency requirements. This SWMP
must be implemented at the start of construction.
The SWMP Administrator, General Contractor, and all subcontractors involved with a
construction activity that disturbs site soil or who implement a pollutant control measure
identified in the SWMP must comply with the requirements of the Colorado Discharge Permit
System (CDPS) General Permit (“General Permit”) and any local governing agency having
jurisdiction concerning CDPS, stormwater, erosion and sedimentation control.
Construction phase pollutant sources anticipated at the site are disturbed (bare) soil, vehicle
fuels and lubricants, and chemicals and coatings associated with paving, as well as
construction-generated litter and debris. Without adequate control there is a potential for each
type of pollutant to be transported by stormwater.
Project construction will consist primarily of demolition, site grading, installation of utilities,
installation of curb/gutter, pavement, and sidewalk, and installation of landscape and irrigation
improvements located within the permitted project area. No construction activity is allowed
outside of the permitted boundary.
A. Purpose
A major goal of pollution prevention efforts during project construction is to control soil
and pollutants that originate on the site and prevent them from flowing to surface waters.
The purpose of this SWMP is to provide guidelines for achieving that goal. A successful
pollution prevention program also relies upon careful inspection and adjustments during
the construction process in order to enhance its effectiveness.
B. Scope
This SWMP must be implemented before construction begins on the site. It primarily
addresses the impact of storm rainfall and runoff on areas of the ground surface
disturbed during the construction process. In addition, there are recommendations for
controlling other sources of pollution that could accompany major construction activities.
Applicability of this SWMP will terminate when disturbed areas are stabilized, permanent
erosion and sedimentation controls are installed, temporary erosion and sedimentation
controls are removed, construction activities covered herein have ceased and a
completed Inactivation Notice is transmitted to the governing agency.
Forms which are necessary for implementing the SWMP are included in the Appendix.
The General Permit for Stormwater Discharges Associated with Construction Activities
prohibits most non-stormwater discharges during the construction phase. Allowable non-
stormwater discharges that occur during construction on this project, which are covered
by the General Permit (in accordance with Part I.D.3), include:
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1. Discharges from emergency fire-fighting activities;
2. Landscape irrigation return flow;
3. Uncontaminated springs and groundwater.
Best Management Practices (BMPs) must be implemented for the above allowable
discharges for the duration of the permit. Each non-stormwater discharge should be
noted in the SWMP and have proper erosion and sedimentation controls in place with
the possible exception of discharges from fire fighting activities.
The techniques described in this SWMP focus on providing control of pollutant
discharges with practical approaches that utilize readily available expertise, material,
and equipment.
Site Location
The site consists of Lot 1, TGS College Avenue Subdivision, A part of Section 1, Township 7
North, Range 69 West of the Sixth Principal Meridian, City of Fort Collins, County of Larimer,
State of Colorado. More specifically it is bound by N. College Ave. to the west, an existing
bowling alley and driveway to the north, an existing liquor store to the east, and an existing car
dealership to the south.
Historically, this site drains generally from west to east by sheet flowing across the asphalt
pavement and enters the regional detention facility located to the east of the site. The historical
drainage patterns will be modified to collect the majority of runoff on-site and drain to the west
into the City of Fort Collins existing storm network.
Current Developed Conditions
The site is approximately 0.31 acres in size. The topography for the site generally slopes to the
southeast at slopes ranging from 0.5% to 1.5%. Elevations range from approximately 4967 to
4969 feet above sea level. The soils within the site are primarily Nunn clay loam, and fall into
Hydrologic soils group Type C. The vegetation consists only of a couple deciduous and conifer
trees. The estimated vegetative ground cover for this site is approximately 3%.
The current site includes an existing 2,330 sq. ft. building and has asphalt and concrete paving
over the entirety of the site except the 450 sq. ft. raised flower box along the south property line.
Nature and Purpose of Construction
The existing 2,330 sq. ft. building will be expanded to become approximately 4,750 sq. ft. In
addition, the parking facilities will be upgraded and landscaping installed in front of the building.
Nearly the entire site will be disturbed. Grading operations shall be performed along all property
lines to match existing grades. The existing building will have approximately 840 sq. ft. of
demolition prior to expanding by 3,260 sq. ft. Total disturbed area is approximately 0.27 acres of
the site.
Closest receiving waters is the Poudre River approximately 0.5 miles to the south of the site.
Flows enter the Regional detention facilities and the City of Fort Collins storm network prior to
entering the receiving waters.
Page 3
STORMWATER MANAGEMENT PLAN
Part I.C.1 – Site Description
Described below are the major construction activities that are the subject of this Erosion and
Sediment Control Plan. Also included in the sequence are BMP installation activities that must
take place prior to construction activities. NOTE: Down slope protective measures must always
be in place before soil is disturbed. Activities are presented in the order (sequence) they are
expected to be completed.
The sequence of construction is as follows:
1. Install staging area, perimeter silt dike, silt fence, and construction fence, and Vehicle
Tracking Control;
2. Install inlet protection on existing storm inlets;
3. Demolish asphalt pavement and building;
4. Begin rough grading;
5. Install water quality facilities, storm sewer and other utilities;
6. Install Inlet Protection at all inlet structures as each structure is installed;
7. Install Curb and Gutter;
8. Construct Building;
9. Pave parking lot areas;
10. Complete grading and install permanent stabilization over all areas per the approved
Landscape Plans for this project.
The actual schedule for implementing pollutant control measures will be determined by project
construction progress and recorded by the SWMP Administrator on the Soil
Erosion/Sedimentation Control Operation Time Schedule on the Erosion and Sedimentation
Control plans (Site Maps). Down slope protective measures must always be in place before soil
is disturbed.
The grading operations for the proposed improvements will disturb approximately 0.31 acres. Cuts
and fills ranging from -0.5 to +2 feet are expected during grading operations. The final grading
could see a net fill of approximately 400 cubic yards. These quantities are approximate and do not
include over-excavation or shrink/swell factors. The contractor is responsible for performing their
own calculations for the earthwork. The Contractor is responsible for hauling and disposing of any
excess cut in an appropriate manner. Once the grading is complete, the site will be stabilized with
permanent landscaping as well as seeding and mulching. Refer to the plans for location and limits
of the grading operations.
The SWMP Administrator is to communicate all deviations and revisions to the developer and
the City of Fort Collins. The revisions are to be marked on the plans that are posted in the
construction trailer.
The erosion potential for the site will vary at different stages of construction. The initial
earthwork operations will remove the existing topsoil and vegetation. This will expose bare earth
to rainfall erosion and wind erosion. As grading operations progress for cuts and fills,
compaction and wetting will reduce wind and rain erosion. Once grading is complete, all
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prescribed measures will be implemented to limit sediment discharge off-site. Temporary
seeding will further reduce erosion potential.
Part I.C.2 – Site Map
Erosion Control Plans have been prepared for this project as part of the Utility Plans. A copy of
these plan sheets are included in Appendix B of this report. The SWMP Administrator shall post
full sized copies (signed by the Engineer of Record) in the construction trailer.
The site BMP’s depicted on these plan sets are tentative and subject to change based on the
condition of the soils, fill requirements, and contractor’s needs. Should additional or different
BMPs become necessary, the plans are to be marked up by the SWMP Administrator to reflect
the deviances from the approved plan set.
Part I.C.3 – Stormwater Management Controls
A variety of stormwater pollutant controls are recommended for this project. Some controls are
intended to function temporarily and will be used as needed for pollutant control during the
construction period. These include minimizing the limit of disturbance, temporary silt dikes,
vehicle tracking control and inlet protection. Permanent stabilization will be accomplished in all
disturbed areas by covering the soil with concrete, vegetation or other forms of soil stabilization.
A. Erosion and Sediment Controls
a. Minimization of Disturbed Areas
Note to General Contractor: Owner and/or SWMP Administrator has authority
to limit surface area of erodible earth material exposed by clearing and grubbing,
excavation, borrow and embankment operations and to direct General Contractor
to provide immediate permanent or temporary pollution control measures.
b. Soil Stabilization
The purpose of soil stabilization is to prevent soil from eroding and leaving the
site. In the natural condition, soil is stabilized by native vegetation. The primary
technique to be used at this project for stabilizing site soils will be to provide a
protective cover of grass or pavement.
i. Temporary Seeding or Stabilization – After construction begins, soil
surface stabilization shall be applied within fourteen (14) days to all
disturbed areas that may or may not be at final grade but will remain
undisturbed for periods longer than thirty (30) calendar days or for and
indeterminate length of time. Stockpiles, sediment basins and diversion
ditches/berms must be stabilized to prevent erosion and dust issues.
Note to General Contractor: Temporary stabilization is not achieved
simply through seeding. In order for an area or stockpile to be sufficiently
stabilized via temporary vegetation, seed must germinate, grow and
provide adequate vegetative density.
ii. Permanent Seeding, Sod or Mulching – All areas at final grade must be
seeded or covered with sod within 14 days after completion of work in
that area. Seed immediately after final grade is achieved and soils are
prepared to take advantage of soil moisture and seed germination. At the
completion of ground-disturbing activities the entire site must have
permanent vegetative cover, meeting vegetative density requirements, or
mulch per construction plan, in all areas not covered by hardscape.
Page 5
Seeded areas shall be protected with straw mulch or a rolled erosion
control product. Straw mulch must be tackified or crimped by disc or other
machinery and rolled erosion control products must be installed per
manufacturer recommendations.
Consideration is given to climate conditions, soil type and native
vegetation when designing the final landscaping plan.
To minimize the potential for erosion and maximize seed germination &
growth, the SWMP Administrator and the General Contractor must
evaluate the short and long-term local forecast prior to applying
permanent seed or sod.
Final site stabilization is achieved when perennial vegetative cover provides
permanent stabilization with a density greater than 70 percent over the entire
area to be stabilized by vegetative cover. This area is exclusive of areas that are
covered with rock (crushed granite, gravel, etc.) or landscape mulch, paved or
have a building or other permanent structure on them.
c. Structural Controls
Structural controls for this site consist of silt dike, vehicle tracking control, inlet
protection and permanent seeding and landscaping per the approved Landscape
Plans for this project. Refer to Appendix B and D of this report for erosion and
sedimentation control notes, BMP locations, and BMP details for this project.
i. Silt Dike – Silt dike is a temporary storm conveyance structure to divert
runoff from leaving the site. Adhesives dikes shall be liquid nail or
approved equal for concrete pavement and emulsified asphalt
applications. Adhesive shall be placed where the units overlap and a 20-
inch strip along both edges. Installed silt dike unit shall have continuous
and firm contact with pavement.
ii. Vehicle Tracking Control – All access points from the adjacent street
into the construction site shall include a construction exit composed of
course stone to the dimensions shown on the Erosion Control detail
sheets included in Appendix D of this report. The rough texture of the
stone helps to remove clumps of soil adhering to the construction vehicle
tires through the action of vibration and jarring over the rough surface and
the friction of the stone matrix against soils attached to vehicle tires.
In addition to the stone at the construction exit, it may be necessary to
install devices such as pipes (cattle guard) to increase the vibration and
jarring. It may also be necessary to install a wheel wash system. If this is
done, a sediment trap control must be installed to treat the wash water
before it discharges from the site.
All site access must be confined to the construction exit(s). Barricade to
prevent the use of any locations other than the construction exit(s) where
vehicles or equipment may access the site. Use jersey barriers,
construction fencing/drums, etc. near construction exit(s) to prevent traffic
by-pass or short circuiting.
Page 6
iii. Storm Sewer Inlet Protection – Curb and grated inlets are protected
from the intrusion of sediment through a variety of measures as shown on
the Erosion Control detail sheets included in Appendix D of this report.
The primary mechanism is to place controls in the path of flow sufficient
to slow the sediment-laden water to allow settlement of suspended soils
before discharging into the storm sewer. It is possible that as construction
progresses from storm sewer installation through to paving that the inlet
protection devices will change.
Note to General Contractor: All inlet protection devices create ponding
of stormwater that can result in flooding or by-pass conditions.
B. Other Pollutant Controls
This section includes the controls of pollutants other than sediment and additional
requirements of the General Permit.
a. Dust Control
Construction traffic must enter and exit the site at the stabilized construction exit
(VTC). The purpose is to trap dust and mud that would otherwise be carried
beyond the permitted project area by construction traffic. Large areas of soil that
are stripped of vegetation and have no protection from particles being picked up
and carried by wind should be protected with a temporary cover or kept under
control with water or other soil adhering products to limit wind transported
particles exiting the site perimeter.
Water trucks or other dust control agents will be used as needed during
construction to minimize dust generated on the site. Tackifiers may be used to
hold soil in place and prevent dust. Manufacturer recommendations for
application locations and rates must be used for dust control applications. Dust
control must be provided by the General Contractor to a degree that is in
compliance with applicable local and state dust control regulations.
b. Dewatering
Verified discharges from dewatering activities are allowed non-stormwater
discharges under the General Permit. The General Contractor shall obtain a
separate dewatering permit according to state and local regulations, if discharges
from dewatering activities are required. Discharges from dewatering operations
must be directed through an appropriate pollution prevention/treatment measure,
such as a pump discharge filter bag, sediment trap or sediment basin prior to
being discharged from the site or into a water body of the State. Under no
circumstances are discharges from dewatering operations to be discharged
directly into streams, rivers, lakes or other areas beyond the permitted project
area. Likewise, discharges into storm sewer systems that do not drain to a
suitable on-site treatment facility, such as a basin, are also prohibited.
Discharges from dewatering operations must also be conducted in a manner
sufficient to prevent erosion from the discharge runoff.
Use best management practices when dewatering. Place intake hose on a
flotation or similar device and do not pump directly from the bottom of the basin,
trench, etc. Always pump through a sediment control BMP and dewater within
the permitted limits of disturbance to ensure discharge criteria are achieved. Do
not discharge on a slope greater than three percent or within 20’ of a surface
Page 7
water body. Dewatering should not occur during or immediately after precipitation
events, but exceptions will be evaluated on case by case basis.
c. Solid Waste Disposal
No solid materials are allowed to be discharged from the site with stormwater.
All solid waste, including disposable materials incidental to major construction
activities, must be collected and placed in containers. The containers will be
emptied when 95% full, or as necessary, by a certified trash disposal service and
hauled away from the site. Covers for the containers will be provided as
necessary to meet state and local requirements. Construct covers as practicable,
or required, to prevent stormwater contact and pollutant discharges from solid
waste receptacles.
Substances that have the potential for polluting surface and/or groundwater must
be controlled by whatever means necessary in order to ensure that they do not
discharge from the site. As an example, special care must be exercised during
equipment fueling and servicing operations. If a spill occurs, it must be contained
and disposed of so that it will not flow from the site or enter groundwater, even if
this requires removal, treatment, and disposal of soil. In this regard, potentially
polluting substances should be handled in a manner consistent with the impact
they represent.
d. Sanitary Facilities
All personnel involved with construction activities must comply with state and
local sanitary or septic system regulations. Temporary sanitary facilities will be
provided at the site throughout the construction phase. They must be utilized by
all construction personnel and will be serviced by a commercial operator.
Portable toilets must be securely anchored and are not allowed within 30’ of
inlets or permitted limit of disturbance or within 50’ of a water of the State.
Secondary containment of the sanitary facilities is not necessary per the General
Permit.
e. Non-Stormwater Discharges
Non-stormwater components of site discharges must be clean water. Water used
for construction which discharges from the site must originate from a public water
supply or private well approved by the State Health Department. Water used for
construction that does not originate from an approved public supply must not
discharge from the site. It can be retained in the ponds until it infiltrates and
evaporates. Other non-stormwater discharges would include ground water. Only
uncontaminated ground water can be discharged from the site, as allowed by
and in accordance with applicable local ground water dewatering
permits/regulations. While groundwater is not anticipated to be encountered
during construction, if the General Contractor does encounter groundwater, the
appropriate permit must be obtained from the State of Colorado. When non-
stormwater is discharged from the site, it must be done in a manner such that it
does not cause erosion of the soil during discharge.
Process water such as power washing and concrete cutting must be collected for
treatment and disposal. It is not to be flushed into the site storm drain system.
f. Concrete Waste from Concrete Ready-Mix Trucks
Discharge of excess or waste concrete and/or wash water from concrete trucks
will be allowed on the construction site, but only in approved above ground
Page 8
portable concrete washout containers (preferred) or in specifically designated
lined and diked areas prepared to prevent contact between the concrete and/or
wash water and stormwater that will be discharged from the site. The General
Contractor shall eliminate or minimize the number of seams in the liner. The
General Permit authorizes the conditional discharge of concrete washout water
to the ground. However, no washout water from the concrete washout activities
can be discharged from the site as surface runoff or to surface waters.
The cured residue from the concrete washout diked areas shall be disposed in
accordance with applicable state and federal regulations. The jobsite
superintendent is responsible for assuring that these procedures are followed.
The location of concrete washout areas shall be shown on the Erosion Control
Plans included in Appendix B of this report. Follow all applicable environmental
regulations for concrete wash out pits.
g. Masons’ Area
The SWMP Administrator shall identify masons’ area on the site and indicate
location on the Site Map. To the extent practical, all masonry tools, material,
including sand and sacked cement or mortar materials, and equipment shall be
located within the area identified. Runoff control, such as berms or diversion
ditches, silt fence, straw wattles, or other means of containment shall be provided
as needed to prevent the migration of stormwater pollutants in runoff from the
masons’ area. Receptacles for debris and trash disposal shall also be provided.
h. Fuel Tanks
Temporary on-site fuel tanks for construction vehicles shall meet all state and
federal regulations. Tanks shall have approved spill containment with the
capacity required by the applicable regulations. From NFPA 30: All tanks shall be
provided with secondary containment (i.e. containment external to and separate
from primary containment). Secondary containment shall be constructed of
materials of sufficient thickness, density, and composition so as not to be
structurally weakened as a result of contact with the fuel stored and capable of
containing discharged fuel for a period of time equal to or longer than the
maximum anticipated time sufficient to allow recovery of discharged fuel. It shall
be capable of containing 110% of the volume of the primary tank if a single tank
is used, or in the case of multiple tanks, 150% of the largest tank or 10% of the
aggregate, whichever is larger.
The tanks shall be in sound condition free of rust or other damage which might
compromise containment. Fuel storage areas will meet all EPA, OSHA and other
regulatory requirements for signage, fire extinguisher, etc. Hoses, valves, fittings,
caps, filler nozzles, and associated hardware shall be maintained in proper
working condition at all times. If required, the SWMP Administrator shall show the
location of fuel tanks on the Site Maps and fuel tanks shall be located to minimize
exposure to weather and surface water drainage features.
A Spill Prevention, Control and Countermeasure (SPCC) Plan must be
developed if aboveground oil storage capacity at the construction site exceeds
1,320-gallons. Containers with a storage capacity of 55-gallons or less are not
included when calculating site storage capacity. The General Contractor shall
work with the SWMP Administrator to develop and implement a SPCC Plan in
accordance with the Oil Pollution Prevention regulation at Title 40 of the Code of
Federal Regulations, Part 112, (40 CFR 112).
Page 9
i. Hazardous Material Management and Spill Reporting Plan
Any hazardous or potentially hazardous material that is brought onto the
construction site will be handled properly in order to reduce the potential for
stormwater pollution. All materials used on this construction site will be properly
stored, handled, dispensed and disposed of following all applicable label
directions. Flammable and combustible liquids will be stored and handled
according to 29 CFR 1926.152. Only approved containers and portable tanks
shall be used for storage and handling of flammable and combustible liquids.
Material Safety Data Sheets (MSDS) information will be kept on site for any and
all applicable materials.
In the event of an accidental spill, immediate action will be undertaken by the
General Contractor to contain and remove the spilled material. All hazardous
materials, including contaminated soil and liquid concrete waste, will be disposed
of by the Contractor in the manner specified by federal, state and local
regulations and by the manufacturer of such products. As soon as possible, the
spill will be reported to the appropriate agencies. As required under the
provisions of the Clean Water Act, any spill or discharge entering waters of the
United States will be properly reported. The General Contractor will prepare a
written record of any spill and associated clean-up activities of petroleum
products or hazardous materials in excess of 1 gallon or reportable quantities,
whichever is less. A spill report form is located in Appendix E.
Any spills of petroleum products or hazardous materials in excess of Reportable
Quantities as defined by EPA or the state or local agency regulations, shall be
immediately reported to the EPA National Response Center (1-800-424-8802)
and the Colorado Department of Public Health and Environment (303-692-3320)
or (1-877-518-5608).
The State reportable quantity for petroleum products is: 25 gallons or any
quantity that will get into the stormwater system.
The reportable quantity for hazardous materials can be found in 40 CFR 302 and
www.cdphe.state.co.us/hm/spillsandreleases.htm.
1. All materials with hazardous properties (such as pesticides, petroleum
products, fertilizers, detergents, construction chemicals, acids, paints, paint
solvents, additives for soil stabilization, concrete, curing compounds and
additives, etc.) will be stored in a secure location, under cover and in
appropriate, tightly sealed containers when not in use.
2. The minimum practical quantity of all such materials will be kept on the job
site and scheduled for delivery as close to time of use as practical.
3. A spill control and containment kit (containing for example, absorbent
material such as kitty litter or sawdust, acid neutralizing agent, brooms, dust
pans, mops, rags, gloves, goggles, plastic and metal trash containers, etc.)
will be provided on the construction site and location(s) shown on Site Maps.
4. All of the product in a container will be used before the container is disposed
of. All such containers will be triple rinsed, with water prior to disposal. The
rinse water used in these containers will be disposed of in a manner in
compliance with state and federal regulations and will not be allowed to mix
with stormwater discharges.
Page 10
5. All products will be stored in and used from the original container with the
original product label.
6. All products will be used in strict compliance with instructions on the product
label.
7. The disposal of excess or used products will be in strict compliance with
instructions on the products label.
i. Long-Term Pollutant Controls
Stormwater pollutant control measures installed during construction, that will also
provide stormwater management benefits after construction, include permanent
seeding, sod, and permanent landscaping. Site stability must reach 70%
stabilization prior to the filing of the Inactivation Notice.
C. “Best Management Practices” (BMPs)
The Owner has authority to limit surface area of erodible earth material exposed by
clearing and grubbing, excavation, borrow and embankment operations and to direct the
SWMP Administrator and General Contractor to provide immediate permanent or
temporary pollution control measures.
During the construction phase, the SWMP Administrator shall implement the following
measures:
a. Materials resulting from clearing and grubbing or excavation operations shall be
stockpiled up slope from adequate sedimentation controls. Materials removed to
sites beyond the permitted project area shall be protected with appropriate
controls and properly permitted and otherwise comply with applicable laws, all in
accordance with this SWMP.
b. The SWMP Administrator shall designate areas on the Site Maps for equipment
cleaning, maintenance, and repair. The General Contractor and subcontractors
shall utilize such designated areas. Cleaning, maintenance, and repair areas
shall be protected by a temporary perimeter berm, shall not occur within 150 feet
of any waterway, water body or wetland, and in areas located as far as practical
from storm sewer inlets.
c. Use of detergents for large scale washing is prohibited (i.e. vehicles, buildings,
pavement surfaces, etc.).
d. Chemicals, paints, solvents, fertilizers, and other toxic materials must be stored
in waterproof containers. Except during application, the containers, the contents
must be kept in trucks or within storage facilities. Runoff containing such material
must be collected, removed from the site, treated, and disposed of at an
approved solid waste and chemical disposal facility.
Part I.C.4 – Final Stabilization and Long-term Stormwater Management
Permanent stabilization will be achieved once the building and parking lot has been completed
and seeding is established providing a density of coverage equal to at least 70% of the original
coverage for the disturbed area. Final stabilization shall be installed per the approved
Landscape Plans for this project. In the interim, the erosion control measures will remain intact
and maintained.
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Part I.C.5 – Inspection and Maintenance
The erosion control measures are to be inspected and maintained at least every seven (7) days
and within 24 hours of any precipitation or snowmelt event that causes surface erosion by the site
project superintendent during construction. Gravel inlet protection is to be checked weekly for
gravel infiltration into inlets and cleaned or increased as necessary. Mulching of bare soils will be
checked regularly and areas of loss or damage are to be re-mulched within seven working days
as necessary. Street cleaning is to be done in a timely manner either by hand or street cleaner
immediately following the deposition. Flushing of squalment with water is prohibited.
Between the time this SWMP is implemented and final Inactivation Notice has been submitted,
all disturbed areas and pollutant controls must be inspected and maintained at least every
seven days. The purpose of site inspections is to assess performance of pollutant controls. The
inspections will be conducted by the SWMP Administrator or his designated alternate. Based on
these inspections, the SWMP Administrator will decide whether it is necessary to modify this
SWMP, add or relocate controls, or revise or implement additional Best Management Practices
in order to prevent pollutants from leaving the site via stormwater runoff. The SWMP
Administrator has the duty to cause pollutant control measures to be repaired, modified,
supplemented, or take additional steps as necessary in order to achieve effective pollutant
control. Note: If a BMP is covered by snow, mark the BMP as not applicable and document the
reason the BMP cannot be inspected on the weekly report.
Examples of specific items to evaluate during site inspections are listed below. This list is not
intended to be comprehensive. During each inspection, the inspector must evaluate overall
pollutant control system performance as well as particular details of individual system
components. Additional factors should be considered as appropriate to the circumstances. The
SWMP Administrator is responsible for measuring and recording site-specific rainfall amounts.
A. Construction Exit and Track Out
Locations where vehicles enter and exit the site must be inspected for evidence of
sediment tracking beyond the permitted project area. A stabilized construction exit shall
be constructed where vehicles enter and exit. Exits shall be maintained or supplemented
with additional rock as necessary to prevent the release of sediment from vehicles
leaving the site. Any sediment deposited on the roadway shall be swept as necessary
throughout the day or at the end of every day and disposed of in an appropriate manner.
Sediment shall NOT be washed into storm sewer systems.
B. Erosion Control Devices
Rolled erosion control products (nets, blankets, turf reinforcement mats) and marginally
vegetated areas (areas not meeting required vegetative densities for final stabilization)
must be inspected every seven days. Rilling, rutting and other signs of erosion indicate
the erosion control device is not functioning properly and additional erosion control
devices are warranted.
C. Sediment Control Devices
Sediment barriers, traps and basins must be inspected and they must be cleaned out at
such time as their original capacity has been reduced by 50 percent. All material
excavated from behind sediment barriers or in traps and basins shall be incorporated
into on-site soils or spread out on an upland portion of the site and stabilized. To
minimize the potential for sediment releases from the project site perimeter control
devices shall be inspected with consideration given to changing up-gradient conditions.
D. Material Storage Areas
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Material storage areas should be located to minimize exposure to weather. Inspections
shall evaluate disturbed areas and areas used for storing materials that are exposed to
rainfall for evidence of, or the potential for, pollutants entering the drainage system or
discharging from the site. If necessary, the materials must be covered or original covers
must be repaired or supplemented. Also, protective berms must be constructed, if
needed, in order to contain runoff from material storage areas. All state and local
regulations pertaining to material storage areas will be adhered to.
E. Vegetation
Consideration must be given to anticipated climate and seasonal conditions when
planting seed. Seed shall be free of weedy species and appropriate for site soils and
regional climate. Seed and mulch per the approved Landscape Plans and the planting
specification immediately after topsoil is applied and final grade is reached. Grassed
areas shall be inspected to confirm that a healthy stand of grass is maintained. The site
has achieved final stabilization once all areas are covered with concrete, or have a stand
of grass with a minimum of 70 percent density or greater of natural background cover
over the entire vegetated area in accordance with the General Permit requirements.
Vegetated areas must be watered, fertilized, and reseeded as needed to achieve this
requirement. The vegetative density must be maintained through project completion to
be considered stabilized. Areas protected by erosion control blankets are not
permanently stabilized until the applicable General Permit requirement for final
vegetative density is achieved.
Rip-rap, mulch, gravel, decomposed granite or other equivalent permanent stabilization
measures may be employed in lieu of vegetation based on site-specific conditions and
governing authority approval.
F. Discharge Points
All discharge points must be inspected to determine whether erosion and sediment
control measures are effective in preventing discharge of sediment from the site or
impacts to receiving waters.
G. Special Project Areas
There are no special projects area, located beyond the permitted project area, requiring
inspection and maintenance associated with this construction project.
H. Sediment Releases
Records of spills, leaks or overflows that result in the discharge of pollutants must be
documented and maintained. Information that needs to be recorded for each discharge
includes the time and date of the discharge or spill, weather conditions, reasons for the
discharge or spill and corrective actions taken by the General Contractor.
Some spills may need to be reported to CDPHE immediately. These spills include: a
release of any chemical, oil, petroleum product or sewage which may enter waters of the
State of Colorado (which include surface water, ground water and fry gullies or storm
sewers leading to surface water. Guidance for the exact requirements to report a spill to
CDPHE can be found at www.cdphe.state.co.us/hm/spillandreleases.htm. CDPHE’s toll-
free number for environmental and chemical spills and releases is 1-877-518-5608.
The Inspection Report Form, included in Appendix C of this report, must identify all deficiencies,
any corrections, whether they are identified during the current inspection or have occurred since
the previous inspection, and any additional comments. Based on inspection results, any
modification necessary to increase effectiveness of this SWMP to an acceptable level must be
made immediately but no longer than within 48 hours of the inspection. The inspection reports
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must be complete and additional information should be included if needed to fully describe a
situation. An important aspect of the inspection report is the description of additional measures
that need to be taken to enhance plan effectiveness. The inspection report must identify
whether the site was in compliance with the SWMP at the time of inspection and specifically
identify all incidents of non-compliance.
Ultimately, it is the responsibility of the SWMP Administrator to assure the adequacy of site
pollutant discharge controls. Actual physical site conditions or contractor practices could make it
necessary to install more structural controls than are shown on the plans. For example,
localized concentrations of runoff could make it necessary to install additional sediment barriers.
Assessing the need for additional controls and implementing them or adjusting existing controls
will be a continuing aspect of this SWMP until the site achieves final stabilization. Any
modifications, additions or deletions of sediment control devices that may alter the hydraulic
design of the site or are located in areas of potential high flow (basins, traps, check dams,
diversions. etc.) must be approved by the developer and engineer through a request for
information (RFI).
CONCLUSION
Compliance with Standards
The proposed erosions control procedures for The Green Solution was designed to meet the
Colorado Department of Public Health and Environment Colorado Discharge Permit System
(CDPS) construction activities stormwater management requirements.
Drainage Concept
The drainage system for The Green Solution was designed to allow storm water to be safely
conveyed through and away from the site without negatively impacting downstream or upstream
properties (regionally) beyond that imposed by the historic condition. The drainage concepts
proposed for this site are in accordance with those presented in previous reports. All drainage
facilities proposed with this development are private facilities and will be maintained by the
property owner or future assigns.
Sediment and Erosion Control Concept
The construction BMP’s proposed for this site follow the requirements of the CDPHE and
recommendations by UDFCD. Attention to proper installation and maintenance are essential for
the sediment and erosion control practices to function properly.
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REFERENCES
1. Urban Drainage and Flood Control District, Denver, Colorado, Urban Storm Drainage
Criteria Manual, Volumes 1, 2 & 3, November 2010.
2. Colorado Department of Public Health and Environment, Denver, Colorado, Stormwater
Management Plan Preparation Guidance, April 2011.
APPENDIX A
VICINITY MAP
SOILS MAP
APPENDIX B
SITE MAPS
APPENDIX C
SEQUENCE SCHEDULE
APPENDIX D
EROSION CONTROL DETAILS
APPENDIX E
EROSION CONTROL SECURITY CALCULATIONS
APPENDIX F
SPILL REPORT FORM
Spill Report Form
The Green Solution:
Spill Reported by:
Date/Time Spill:
Date/Time Spill reported to CDPHE Hotline:
Describe spill location and events leading to spill:
Material spilled:
Source of spill:
Amount spilled (gallons): Amount spilled to waterway:
Containment or clean up action:
Approximate depth of soil excavation:
List Injuries or Personal Contamination:
Action to be taken to prevent future spills:
Modifications to the SWMP, including required sampling, necessary due to this spill:
Agencies notified of the spill:
I certify under penalty of law that this document and all attachments were prepared under my direction or
supervision in accordance with a system designed to assure that qualified personnel properly gather and
evaluate the information submitted. Based on my inquiry of the person or persons who manage the
system, or those persons directly responsible for gathering the information, the information submitted is,
to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are
significant penalties for submitting false information, including the possibility of fine and imprisonment for
knowing violations.
Contractor Superintendent Date