HomeMy WebLinkAboutLANDMARK RESIDENCES ON MOUNTAIN AVENUE - FDP - FDP150019 - SUBMITTAL DOCUMENTS - ROUND 1 - STORMWATER MANAGEMENT PLANSTORMWATER MANAGEMENT PLAN (SWMP)
Landmark Residences
on Mountain Avenue
Fort Collins, CO
May 6, 2015
Prepared for:
Savant Homes Inc.
P.O. Box 2066
Fort Collins, CO 80522
Prepared by:
301 North Howes Street, Suite 100
Fort Collins, Colorado 80521
Phone: 970.221.4158 Fax: 970.221.4159
www.northernengineering.com
Project Number: 1022-001
This Drainage Report is consciously provided as a PDF.
Please consider the environment before printing this document in its entirety.
When a hard copy is absolutely necessary, we recommend double-sided printing.
May 6, 2015
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, Colorado 80521
RE: Stormwater Management Plan
Landmark Residences on Mountain Avenue
To Whom It May Concern:
Northern Engineering Services, Inc. is pleased to submit this Stormwater Management Plan for
Landmark Residences on Mountain Avenue. This report outlines Best Management Practices
(BMPs) to be implemented with the proposed construction in order to minimize potential pollutants
in stormwater discharges.
We have prepared this report to accompany the Colorado Department of Public Health and
Environment General Permit for Stormwater Discharge Associated with Construction Activities (aka,
Stormwater Discharge Permit or SDP). The General Permit No. for this SDP is (to be filled-in by
permittee) and the Certification No. for this SDP is (to be filled-in by permittee). The Permit
Certification is Effective beginning (to be filled-in by permittee), and initial certification expires (to be
filled-in by permittee). A copy of the issuance cover letter can be found in the Appendix D of this
document (to be provided by permittee).
Please note: this Stormwater Management plan (including the Site Maps) is not a static document.
It is a dynamic device that should be kept current and logged as construction takes place. As such,
this version was prepared to facilitate initial plan approvals and permitting, but does not necessarily
reflect the final version, or the transitions throughout the construction process. As the site develops
and changes, the Contractor is expected and encouraged to make changes to what is contained
herein so that the SWMP works as effectively and efficiently as possible. It shall be the
responsibility of the SWMP Administrator and/or the permit holder (or applicant thereof) to ensure
the plan is properly maintained and followed.
If you should have any questions or comments as you review this report, please feel free to contact
us at your convenience.
Sincerely,
NORTHERN ENGINEERING SERVICES, INC.
Cody Snowdon
Project Engineer
Landmark Residences on Mountain Avenue
Stormwater Management Plan
TABLE OF CONTENTS
Vicinity Map
1.0 General Requirements ............................................................................................... 1
1.1 Objectives .................................................................................................................. 1
1.2 SMWP Availability ...................................................................................................... 1
1.3 Definitions.................................................................................................................. 1
1.4 Additional Permitting ................................................................................................... 1
2.0 Narrative Site Description .......................................................................................... 2
2.1 Existing Site Description .............................................................................................. 2
2.2 Nature of Construction Activity ..................................................................................... 2
2.3 Sequence of Major Activities ......................................................................................... 2
2.4 Site Disturbance ......................................................................................................... 2
2.5 Existing Data .............................................................................................................. 2
2.6 Existing Vegetation ...................................................................................................... 3
2.7 Potential Pollution Sources ........................................................................................... 3
2.8 Non-stormwater discharges .......................................................................................... 3
2.9 Receiving Waters ........................................................................................................ 4
3.0 Stormwater Management Controls .............................................................................. 4
3.1 SWMP Administrator ................................................................................................... 4
3.2 Best Management Practices (BMP’s) for Stormwater Pollution Prevention .......................... 4
3.3 Structural Practices for Erosion and Sediment Control ..................................................... 5
3.4 Non-Structural Practices for Erosion and Sediment Control .............................................. 7
3.5 Phased BMP Installation .............................................................................................. 9
3.6 Material Handling and Spill Prevention ........................................................................ 10
3.7 Dedicated Concrete or Asphalt Batch Plant .................................................................. 11
3.8 Vehicle Tracking Control ............................................................................................ 11
3.9 Waste Management and Disposal ............................................................................... 11
3.10 Groundwater and Stormwater Dewatering .................................................................... 12
4.0 Final Stabilization and Long-Term Stormwater Management ........................................ 12
4.1 Final Stabilization ..................................................................................................... 12
4.2 Long-Term Stormwater Management ........................................................................... 12
5.0 Inspection, Maintenance and Record Keeping ............................................................ 13
5.1 BMP Inspection ........................................................................................................ 13
5.2 BMP Maintenance .................................................................................................... 13
5.3 Record Keeping ........................................................................................................ 13
6.0 Additional SWMP and BMP Resources ...................................................................... 15
References ............................................................................................................. 16
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LIST OF TABLES:
Table 1 – Preliminary Permit and Construction Schedule ......................................................... 10
APPENDICES:
APPENDIX A – Site Maps
APPENDIX B – Erosion Control Details
APPENDIX C – Landscape Plan
APPENDIX D – Copies of Permits/Applications
APPENDIX E – Inspection Logs
APPENDIX F – Contractor Inserts (as needed)
APPENDIX G – Contractor Inserts (as needed)
Landmark Residences on Mountain Avenue
Stormwater Management Plan 1
1.0 General Requirements
1.1 Objectives
The objective of a Stormwater Management Plan (SWMP) is to identify all potential sources of
pollution likely to occur as a result of construction activity associated with the site construction, and
to describe the practices that will be used to reduce the pollutants in stormwater discharges from
the site. The SWMP must be completed and implemented at the time the project breaks ground,
and revised as necessary as construction proceeds to accurately reflect the conditions and practices
at the site.
This report summarizes the Stormwater Management Plan for the construction activity that will
occur with Landmark Residences on Mountain Avenue in Fort Collins, CO. This plan has been
prepared according to regulations of the Colorado Department of Public Health and Environment
(CDPHE), Water Quality Control Division.
1.2 SMWP Availability
This report is intended to remain on the aforementioned construction site to allow for maintenance
and inspection updates, and for review during inspection.
1.3 Definitions
BMP – Best Management Practice encompassing a wide range of erosion and sediment control
practices, both structural and non-structural in nature, which are intended to reduce or eliminate
any possible water quality impacts from stormwater leaving a construction site.
Erosion Control BMPs – Practices that PREVENT the erosion of soil, such as minimizing the amount
of disturbed area through phasing, temporary stabilization, and preserving existing vegetation.
Sediment Control BMP’s – Practices to REMOVE sediment from runoff, such as sediment basins,
silt fence, or inlet protection.
Non-structural BMP’s – The implementation of methods, practices, and procedures to minimize
water quality impacts, such as the preservation of natural vegetation, preventive maintenance and
spill response procedures.
Structural BMP’s – Physical devices that prevent or minimize water quality impacts, such as
sediment basins, inlet protection, or silt fence.
1.4 Additional Permitting
As mentioned above, this Stormwater Management Plan is associated with the Colorado
Department of Public Health and Environment Stormwater Permit that is issued by the Water
Quality Control Division of the CDPHE. Additional Environmental permitting not described in this
report may be required as a part of this project. An example is the Construction Dewatering Permit
for groundwater. Another example is the Air Pollution Emission Notice (APEN). The CDPHE
website contains links to both of these permits, as well as many other potential permits. The
Contractor is responsible for ensuring the proper permits are acquired.
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2.0 Narrative Site Description
2.1 Existing Site Description
Landmark Residences on Mountain Avenue project is located in the southwest quarter of Section
11, Township 7 North, Range 69 West of the 6th Principal Meridian, City of Fort Collins, County of
Larimer, State of Colorado. 3. The project site is located northeast corner of Shields Street and
Mountain Avenue. Landmark Residences on Mountain Avenue consists of an irregular lot with one
convenient store, three gas pump stations and associated drive and parking areas. The remainder
of the lot consists of landscape areas and tree lawns. The project is currently border to the south by
a Mountain Avenue, west by Shields Street, north by a single-family residence and a public alley
and east by a single-family residence.
2.2 Nature of Construction Activity
The Landmark Residences on Mountain Avenue project will consist of one main building, with four
buildings used for garage parking and storage. The main building will consist of 6 single-family
attached dwellings with one commercial space. The lot will be split into seven individual lots and
one tract consisting of the drive aisle and parking areas. The building will require the installation of
the water, fire and sewer services. The grading of the property will require installation of multiple
storm sewers and associated inlets. This project will include improvements to the public alley north
of the site.
2.3 Sequence of Major Activities
To complete the project, many basic categories of construction activity will take place. The first
part will be the demolition and removal of the existing building, paved areas, vegetation, and
existing noted utilities. Existing underground storage tanks and gas station facilities will be removed
during this phase. Within this phase protection will need to be supplied to the existing storm line
within North Shields Street to ensure no sediment is routed through the existing system. This will
be followed by utility installation and foundation excavation. Vertical construction of the building
will commence after foundation and underground work is complete. New curb/gutter, paving, and
sidewalks are expected to begin after the building is dried in and trades move inside. The final
stages of site construction will be fine grading of the areas around the buildings, and the installation
of landscaping throughout the project. The aforementioned sequencing is an initial best guess, and
is subject to change at the Contractor’s discretion.
2.4 Site Disturbance
The site disturbance will occur in primarily in the site, which is a total area of approximately 0.74
acres, including improvements to existing public alley. Areas of cut and fill are proposed for the
site, primarily fill at the southeast corner of the site.
2.5 Existing Data
In order to complete the associated construction plans, a topographical survey of the site was
completed. This survey consisted of field measurements made by Northern Engineering on April
23, 2014.
In addition to the field survey, the Natural Resources Conservation Service (NRCS) Soil Survey was
used to determine existing soil types found on-site. According to the NRCS Soil Survey, the site
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consists primarily of Fort Collins loam. The Fort Collins loam is classified as Hydrologic Soil Group
C.
2.6 Existing Vegetation
The existing site is approximately 80% covered with hard surfaces (rooftop, paving, etc.) which
allow minimum surface erosion. Minimal landscaping is located within the grassy buffers between
existing sidewalk and North Shields Street, and existing sidewalk and Mountain Avenue, which
allows minimum ground erosion. It is highly recommended that pre-construction photos be taken
to clearly document vegetative conditions prior any disturbance activities.
2.7 Potential Pollution Sources
As is typical with most construction sites, there are a number of potential pollution sources which
could affect water quality. It is not possible for this report to identify all materials that will be used
or stored on the construction site. It is the sole responsibility of the Contractor to identify and
properly handle all materials that are potential pollution sources. The following are some common
examples of potential pollution sources:
Exposed and stored soils
Management of contaminated soils
Off-site tracking of soils and sediment
Loading and unloading operations
Outdoor storage of building materials, fertilizers, chemicals, etc.
Vehicle and equipment maintenance and fueling
Significant dust or particulate generating processes
Routine maintenance activities involving fertilizers, pesticides, detergents, fuels, solvents, oils, etc.
On-site waste disposal practices (waste piles, dumpsters, etc.)
Concrete truck/equipment washing
Non-industrial waste sources that may be significant, such as worker trash and portable toilets
Uncovered trash bins
Other areas or procedures where potential spills can occur
Stockpiling of materials that can be transported to receiving waterway(s)
Management of Contaminated Soils: We are not aware of on-site contaminated soils. However, the
contractor should conduct a thorough, pre-construction environmental site assessment. If
contaminated soils are discovered, the contractor will identify appropriate practices and procedures
for the specific contaminants discovered on-site.
Loading and Unloading Operations: As site development and building construction progresses,
space constraints will limit the number of on-site locations for loading and unloading activities to
the building from Perennial Lane. The contractor will be responsible for the proper handling and
management of pollution sources during loading and unloading operations.
Dedicated Asphalt and Concrete Batch Plants: Neither a dedicated asphalt or concrete batch plant
will be constructed on-site.
2.8 Non-stormwater discharges
The Stormwater Construction Permit only covers discharges composed entirely of stormwater.
Emergency firefighting water is the only authorized exception. Concrete Washout water can NOT be
discharged to surface waters or to storm sewer systems without separate permit coverage. The
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discharge of Concrete Washout water to the ground, under specific conditions, may be allowed by
the Stormwater Construction Permit when appropriate BMPs are implemented.
The discharge of pumped stormwater, ONLY, from excavations, ponds, depressions, etc. to surface
waters, or to a municipal storm sewer system is allowed by the Stormwater Construction Permit, as
long as the dewatering activity and associated BMPs are identified in the Stormwater Management
Plan (SWMP) and are implemented in accordance with the SWMP.
Aside from the exceptions noted above, non-stormwater discharges must be addressed in a separate
permit issued for that discharge. If groundwater is encountered, and dewatering is required, a
Construction Dewatering Permit must be acquired from the Colorado Department of Public Health
and Environment. A copy of the dewatering permit application and instructions has been included
with Appendix D.
2.9 Receiving Waters
Stormwater runoff from this project is designed to drain in two major direction. A majority of the
drainage is routed to the proposed drive aisle and permeable paver section, or to overland flow to
North Shields Street. The storm water is then routed to an existing inlet on North Shields Street
through overland flow or the proposed storm drain. The remaining runoff from the south of the site
flows overland to West Mountain Avenue, then, eastward to an existing inlet on the corner of West
Mountain Avenue and North Mack Street. This storm sewer discharges directly into the City of Fort
Collins Storm Sewer System. Once the runoff is within City’s System, it travels through the system
roughly 1.4 miles to Cache La Poudre River.
3.0 Stormwater Management Controls
3.1 SWMP Administrator
A SWMP Administrator must be designated in conjunction with the Stormwater Permit. This person
shall be responsible for developing, implementing, maintaining, and revising the SWMP. The
SWMP Administrator will also be the contact for all SWMP-related issues and will be the person
responsible for the accuracy, completeness, and implementation of the SWMP. The Administrator
should be a person with authority to adequately manage and direct day-to-day stormwater quality
management activities at the site.
The SWMP Administrator for this site is:
Name: (to be filled-in by permittee)
Company: (to be filled-in by permittee)
Phone: (to be filled-in by permittee)
E-mail: (to be filled-in by permittee)
3.2 Best Management Practices (BMP’s) for Stormwater Pollution Prevention
Beginning from mobilization, and throughout the entire construction of the project, erosion control
devices shall be installed to ensure minimal pollutant migration. These erosion control devices may
be installed in phases, or not at all, depending on actual conditions encountered at the site. It is
the responsibility of the Contractor to make the determination as to what practices should be
employed and when. In the event that a review agency deems BMPs to be insufficient, it shall be
the responsibility of the contractor to implement modifications as directed.
Best Management Practices (BMPs) are loosely defined as a method, activity, maintenance
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procedure, or other management practice for reducing the amount of pollution entering a water
body. The term originated from rules and regulations in Section 208 of the Clean Water Act.
Details for Structural and Non-Structural BMPs have been included in Appendix B. These details
should be used for additional information on installation and maintenance of BMPs specified in this
report. It is also intended to serve as a resource for additional BMPs that may be appropriate for
the site that have not specifically been mentioned in the report.
3.3 Structural Practices for Erosion and Sediment Control
Structural BMPs are physical devices that are implemented to prevent erosion from happening or to
limit erosion once it occurs. These devices can be temporary or permanent, and installation of
individual components will vary depending on the stage of construction.
A table depicting construction sequence and BMP application/removal has been placed on the
“Dynamic Site Plan” to help document the implementation of these BMPs. Refer to the Stormwater
Management Plan Static Site Plan in the Appendix for the assumed location of all BMPs.
Construction Details for Temporary BMPs are located in the Appendix for reference.
Again, the final determination for which BMP’s will be installed, where they will be located, and
when they will be installed shall be made by the Contractor, along with all documentation
throughout the construction process.
Silt Fencing (Phase I)
Silt fencing shall be provided to prevent migration of sediment off-site or into adjacent properties.
All silt fencing shall be installed prior to any land disturbing activity (demolition, stockpiling,
stripping, grading, etc.). Silt fencing is to be installed prior to site excavation or earthwork
activities.
Inspections of the silt fence should identify tears or holes in the material, and should check for
slumping fence or undercut areas that allow flows to bypass the fencing. Damaged sections of the
silt fence should be removed to maintain BMP effectiveness, typically before it reaches a depth of 6
inches.
At a minimum, it is suggested that silt fencing be located around site boundary, as well as along the
north site of the public alley.
Sediment Control Log – aka “Straw Wattles” (Phase I)
A Sediment Control Log is a linear roll made of natural materials, such as straw, coconut fiber, or
other fibrous material trenched into the ground and held with a wooden stake. Sediment Control
Logs can be used in many instances. Examples include perimeter control for stockpiles, as part of
inlet protection designs, as check dams in small drainage ways, on disturbed slopes to shorten flow
lengths, or in lieu of silt fencing (where appropriate).
Sediment Control Logs should be inspected for excess sediment accumulation. Sediment should be
removed prior to reaching half the height of the log.
At a minimum, Sediment Control Logs should be used around soil stockpiles (including landscape
material) and at all stormwater discharge locations other than inlets.
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Vehicle Tracking Control Pads (Phase I)
Vehicle tracking control pads shall be provided to minimize tracking of mud and sediment onto
paved surfaces and neighboring roadways. All vehicle tracking control pads shall be installed prior
to any land disturbing activity (demolition – as necessary, stockpiling, stripping, grading, etc.).
Location of vehicle tracking control pads will be located at any and all existing and future vehicle
accesses being used during any of the construction phases. These locations will primarily be
dictated by gates or openings in the temporary construction fencing that is expected to be installed.
Vehicle tracking control pads are to be installed prior to demolition (as appropriate), site excavation
or earthwork activities.
Vehicle tracking pads should be inspected for degradation and aggregate material should be
replaced as needed. If the area becomes clogged with water, excess sediment should be removed.
Aggregate material should remain rough, and at no point should aggregate be allowed to compact in
a manner that causes the tracking pad to stop working as intended.
Suggested locations for vehicle tracking pads are at the proposed access to the site from North
Shields Street.
Inlet Protection (Phase I & II)
Inlet protection shall be provided for existing inlets to prevent sediment transport from adjacent
earthwork disturbance. Installation of these filters shall occur before adjacent earth disturbing
activities (Phase I implementation). Wattle type filters are to be implemented for new and existing
inlets where asphalt does not exist. For these inlets, if pavement is constructed adjacent to the
structure or if the area adjacent to the inlet is changed such that the wattle type filter is no longer
effective, it shall be the responsibility of the Contractor to ensure that an appropriate method is
used instead. For example, the wattle filter could be reused, or a gravel-block inlet filter may be
installed. It will be left to the discretion of the Contractor as to whether replacement of any inlet
filter is necessary.
Inlet protection should be inspected regularly for tears that can result in sediment entering an inlet.
Inlet protection should also be inspected for sediment accumulation upstream of the inlet, and
sediment should be removed when the less than half of the capacity is available, or per
manufacturer specifications.
The existing inlet on North Shields Street will need protection. The Contractor shall also provide
inlet protection for all proposed inlets as they are installed (Phase II implementation).
Erosion Control Blankets (Phase II)
A temporary degradable rolled erosion control product composed of natural flexible fibers shall be
used on all seeded slopes 3:1 and greater (excluding mulched shrub bed areas). Erosion control
blankets should be utilized to provide erosion control and to facilitate vegetation establishment.
During installation, it is important to ensure that no gaps or voids exist under the material and that
all corners of the material are secured using stakes and trenching. Stakes should be made of
materials that are biodegradable. Continuous contact between the product and the soil is necessary
to avoid failure.
Erosion Control Blankets should be inspected regularly for signs of erosion, including beneath the
mat. If voids are apparent, they should be filled with suitable soil. Inspections should also identify
loose or damaged stakes, as well as loose portions of the blanket. If deficiencies are found, they
should be repaired or replaced.
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Concrete Washout Area (Phase II)
A concrete washout should be provided on the site. The washout can be lined or unlined excavated
pits in the ground, commercially manufactured prefabricated containers, or aboveground holding
areas. The concrete washout must be located a minimum of 400 feet from any natural drainage
way or body of water, and at least 1000 feet from any wells or drinking water sources. Washout
areas should not be located in an area where shallow groundwater may be present. Contractor
shall clearly show the desired location and access to the Concrete Washout Area on the Stormwater
Management Plan - Dynamic Site Plan. Contractor shall place a Vehicle Tracking Pad if the
selected location for the Concrete Washout Area is detached from pavement. Clear signage
identifying the concrete washout should also be provided.
The Concrete Washout Area should be inspected regularly. Particular attention should be paid to
signage to ensure that the area is clearly marked. Confirmation that the washout is being used
should also be noted to ensure that other undesignated areas of the site are not being used
incorrectly as a concrete washout.
An appropriate location for the concrete washout area is located on the east side of site, south of
the proposed garages. This location is a suggestion only, and can be relocated at the discretion of
the Contractor.
Permanent/Established Vegetation (Phase IV)
Permanent or established vegetation and landscaping is considered a permanent form of sediment
and erosion control for common open spaces, steep slopes and areas not exposed to prolonged
scour velocities, or acute incipient motion bed shear stresses that will create soil erosion, rill
formation and subsequent sediment transport. Areas where the previous conditions apply will
contain sufficient permanent BMPs, such as riprap or cobble mulch. Permanent vegetation shall
conform to the approved Landscape Plan prepared by Ripley Design. Permanent/Established
vegetation and hardscape defines Phase IV of development.
3.4 Non-Structural Practices for Erosion and Sediment Control
Non-Structural BMPs are practices or activities that are implemented to prevent erosion from
happening or to limit erosion once it occurs. These BMPs can be a practice resulting in physical
change to the site, such as mulching or slope stabilization. They can also result in behavioral
changes on the site, such as changes to construction phasing to minimize exposure to weather
elements, or increased employee awareness gained through training.
Protection of Existing Vegetation (Phases I-IV)
Protection of existing vegetation on a construction site can be accomplished through installation of a
construction fence around the area requiring protection. In cases where up-gradient areas are
disturbed, it may also be necessary to install perimeter controls to minimize sediment loading to
sensitive areas such as wetlands.
Trees that are to remain after construction is complete must be protected. Most tree roots grow
within the top 12”-18” of soil, and soil compaction is a significant threat to tree health. As such,
particular care should be taken to avoid activities within the drip-line of the tree. Direct equipment
damage should also be prevented. The most effective way to ensure the health of trees is to
establish a protection zone at the drip-line of the tree to prevent unintended activity in the area
directly surrounding the tree.
Fencing should be inspected and repaired when needed. If damage occurs to a tree, an arborist
should be consulted on how to care for the tree. If a tree is damage beyond repair, the City Forester
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should be consulted on remediation measures.
At a minimum, protection to all trees identified for retention on the plans by Ripley Design.
Stockpile Management (Phases I-III)
Stockpile management should be utilized to minimize erosion and sediment transport from soil
stockpiles. In general, soil stockpiles should be located a minimum of 100 feet from any drainage
way and 50 feet from any storm sewer inlets. Where practical, choose a stockpile location that will
remain undisturbed for the longest period of time as the phases of construction progress. Sediment
control BMPs should be placed around the perimeter of the stockpile, and a designated access point
on the upstream side of the stockpile should be identified. BMPs such as surface roughening,
temporary seeding, mulching, erosion control blankets, or soil binders should be used to stabilize
the stockpile surface.
As a part of stockpile management, regular inspections of the perimeter controls should be
completed. If BMPs have been utilized to stabilize the surface of the stockpile, they should be
inspected and repaired as needed.
While significant soil stockpiles are not expected with this project, it is possible that foundation
excavation or the delivery landscaping material may generate temporary stockpiles. The location of
any such stockpiles shall be the responsibility of the SWMP Administrator.
Mulching (Phase I-III)
Mulching helps reduce erosion by protecting bare soil from rainfall impact, increasing infiltration,
and reducing runoff. Although often applied in conjunction with temporary or permanent seeding, it
can also be used for temporary stabilization of areas that cannot be reseeded due to seasonal
constraints. The most common type of mulch used is hay or grass that is crimped into the soil to
keep it secure. However, crimping may not be practical on slopes steeper than three to one
(3H:1V).
The Contractor shall mulch all planted areas within twenty-four (24) hours after planting. Only
weed-free and seed-free straw mulch may be used. Straw mulch should be applied at two (2) tons
per acre, and shall be adequately secured by crimping, tackifier, netting or blankets. Hydraulic
mulching may also be used on steep slopes or where access is limited. In the case that hydraulic
mulching is utilized, the Contractor shall use wood cellulose fibers mixed with water at two
thousands to two thousand five hundred (2,000-2,500) pounds per acre and organic tackifier at
one hundred to four hundred (100-400) pounds per acre.
The Contractor is responsible in applying wood chip mulch to all planted trees and shrubs as shown
on the Landscape Plan prepared by Ripley Design.
Wind Erosion/Dust Control (Phase I-IV)
Wind Erosion and Dust Control BMP’s help to keep soil particles from entering the air as a result of
land disturbing construction activities. Examples include use of a water truck or irrigation/sprinkler
system to wet the top layer of disturbed soil, seeding and mulching, soil binders, or wind fences.
If a water truck or irrigation/sprinkler system is utilized, monitoring to ensure that sufficient water is
applied is crucial to ensuring soil particles don’t become airborne. Equally important is monitoring
for overwatering, as too much water can lead to increased erosion.
Street Sweeping (Phases I -IV)
Street sweeping should be used to remove sediment that has been tracked onto adjacent roadways.
Roadways should be inspected at least once a day, and sediment should be removed as needed. A
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check of the area inlet protection should be completed after sweeping to ensure nothing was
displaced during sweeping operations. Street sweeping can reduce the sediment washed into the
existing storm drain system. Street sweeping may be necessary on the existing hardscape areas
which receive runoff from the disturbed areas.
Saw Cutting Pollution Prevention (Phase I)
The following protocol is recommended to prevent dust and slurry from asphalt and concrete saw
cutting activities from migrating into the existing storm drain system.
Slurry and cuttings shall be vacuumed during cutting and surfacing operations
Slurry and cuttings shall not remain on permanent concrete or asphalt pavement
overnight
Slurry and cuttings shall not drain to any natural or constructed drainage conveyance
Collected slurry and cuttings shall be disposed of in a manner that does not violate
groundwater or surface water standards
Good Housekeeping Practices (All phases)
Good housekeeping practices that will prevent pollution associated with solid, liquid, and hazardous
construction-related materials and wastes should be implemented throughout the project.
Examples of good housekeeping include providing an appropriate location for waste management
containers, establishing proper building material staging areas, designating paint and concrete
washout areas, establishing proper equipment/vehicle fueling and maintenance practices.
Development of a spill prevention and response plan is another example of Good Housekeeping
practices that should be used on the project. The following items are detailed examples of some of
the good housekeeping practices that should be utilized throughout the project. It should be noted
that a complete list of practices and detailed discussion regarding good housekeeping has been
included with Appendix B, sheets GH-1 – GH-6.
Street Sweeping and Vacuuming – Street sweeping and vacuuming should be used to remove
sediment that has been tracked onto adjacent roadways. Roadways should be inspected at least
once a day, and sediment should be removed as needed. A check of inlet protection should be
completed after sweeping to ensure nothing was displaced during sweeping operations.
Waste Management – Designate trash and bulk waste collection areas on-site. When possible,
materials should be recycled. Hazardous material waste should be segregated from other solid
waste. Waste collection areas should be located away from streets, gutters, watercourses, and
storm drains. Dumpsters should be located near site entrances to minimize traffic on disturbed
soils, and they should be placed on a level soil surface.
Establish Proper Building Material Handling and Staging areas – Clearly designate site areas for
staging and storage of building materials. Provide appropriate BMPs to ensure that spills or leaks
are contained.
Establish Proper Equipment/Vehicle Fueling and Maintenance Practices – If needed, create a
clearly designated on-site fueling and maintenance area that is clean and dry. Provide appropriate
BMPs to ensure that spills or leaks are contained.
3.5 Phased BMP Installation
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It is important to recognize the four (4) major Development Phases as defined by the State of
Colorado’s Stormwater Discharge Permit (SDP). These four development phases (referred to as
Sequencing by the City of Fort Collins) have been distinguished to aid in the appropriate timing of
installation/implementation of BMPs at different stages of the construction process. These phases
are described as follows:
Phase I – Grading Stage; BMPs for initial installation of perimeter controls
Phase II – Infrastructure Stage; BMPs for utility, paving and curb installation
Phase III – Vertical Construction Stage; BMPs for individual building construction.
Phase IV – Permanent BMPs and final site stabilization.
The following is a rough estimate of the anticipated construction sequence for site improvements.
The schedule outlined below is subject to change as the project progresses and as determined by
the General Contractor.
Table 1 – Preliminary Permit and Construction Schedule
TASK BEGINNING DATE ENDING DATE "BMP-PHASE OF
DEVELOPMENT"
Development Construction
Permit Issued by City of Fort
Collins
July 2015 July 2015 I
Overlot Grading (Demolition) July 2015 August 2015 I
Utility Installation August 2015 September 2015 II
Building Construction September 2015 March 2016 III
Final Stabilization March 2016 April 2016 IV
Included in the back map pockets are five Site Plans: a “Static” Site Plan and four “Dynamic” Site
Plans. The “Static” plan serves to display the overall management plan all at once. However,
proper implementation of BMPs does not occur at once, and certain BMPs may move location in
the construction process; therefore, the “Dynamic” Site Plans are intended for the Contractor to
write in the BMP symbols to document the location and time the BMPs are installed and
maintained throughout the entire construction process.
3.6 Material Handling and Spill Prevention
Potential pollution sources, as discussed in earlier sections, are to be to be identified by the
Contractor. Spill prevention procedures are to be determined and put in place prior to construction
by the Contractor. A spill and flooding response procedure must also be determined and put in
place prior to construction by the Contractor. Additionally, steps should be taken to reduce the
potential for leaks and spills to come in contact with stormwater runoff, such as storing and
handling toxic materials in covered areas or by storing chemicals within berms or other secondary
containment devices.
A notification procedure must be put in place by the Contractor, by which workers would first notify
the site construction superintendent, who would then 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
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Division, downstream water users, or other appropriate agencies. The release of any chemical, oil,
petroleum product, sewage, etc., which enter waters of the State of Colorado (which include
surface water, ground water, and dry gullies or storm sewers leading to surface water) must be
reported immediately to the Division’s emergency spill reporting line at (877) 518-5608. All
spills that will 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 970-221-6700.
While not expected with this project, it will be the responsibility of the Contractor to designate a
fueling area and take the necessary precautions to ensure that no stormwater pollution occurs in the
event that a fueling area is needed. Fueling areas shall be located a minimum 100 feet from all
drainage courses. A 12-inch high compacted earthen ridge capable of retaining potential spills
shall enclose fueling areas. Other secondary containment devices can be used instead of the
earthen ridge. The area shall be covered with a non-porous lining to prevent soil contamination.
Printed instructions for cleanup procedures shall be posted in the fueling area and appropriate fuel
absorbents shall be available along with containers for used absorbents within the fueling area.
3.7 Dedicated Concrete or Asphalt Batch Plant
There are not any dedicated concrete or asphalt batch plants anticipated with this project. In the
event that a plant is needed, the Contractor should be aware that additional permitting will be
required. In particular, an Air Pollutant Emission Notice (APEN) will need to be obtained from the
CDPHE.
3.8 Vehicle Tracking Control
In addition to the vehicle tracking pads discussed previously, additional measures can be taken to
minimize and control sediment discharges from the site due to vehicle tracking. These measures
can include fencing around the site to control access points. Regular street sweeping can also be
used to minimize the transmission of sediment from the site due to vehicles leaving the site. The
use of gravel parking areas and wash racks can also be implemented to ensure minimal vehicle
tracking from the site.
3.9 Waste Management and Disposal
It will be the responsibility of the Contractor to designate a concrete truck chute washout area and
to clearly identify that area. Detailed information about the design and maintenance of the Concrete
Washout can be found under the Structural Practices section of this report. At no time should
untreated wash water be allowed to discharge from the site or to enter a storm drain system or
stream. Upon completion of construction activities the concrete washout material shall be removed
and properly disposed of prior to the area being restored.
Any waste material that currently exists on the site or that is generated by construction will be
disposed of in such a manner as to not cause pollutants in stormwater discharges. If waste is to be
stored on-site, it shall be in an area located a minimum of 100 feet from all drainage courses.
Whenever waste is not stored in a non-porous container, it shall be in an area enclosed by a 12-
inch high compacted earthen ridge or some other approved secondary containment device. The area
shall be covered with a non-porous lining to prevent soil contamination. Whenever precipitation is
predicted, the waste shall be covered with a non-porous cover, anchored on all sides to prevent its
removal by wind, in order to prevent precipitation from leaching out potential pollutants from the
waste. On-site waste disposal practices, such as dumpsters, should be covered or otherwise
contained as to prevent dispersion of waste materials from wind. It shall also be the responsibility
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of the Contractor to maintain a clean jobsite as to prevent dispersion of waste material and potential
pollutants into adjacent properties or waterways.
The location of, and protective measures for, temporary restroom facilities shall be the responsibility
of the SWMP Administrator.
3.10 Groundwater and Stormwater Dewatering
The BMPs selected for construction dewatering vary depending on the site-specific features, such as
soils, topography, discharge quantities, and discharge location. Typically, dewatering involves
pumping water from an inundated area to a BMP, prior to the water being released downstream
into a receiving waterway, sediment basin, or well-vegetated area. Acceptable BMPs included
discharging water into a sediment trap or basin, using a dewatering filter bag, or using a series of
sediment logs. A settlement tank or an active treatment system can also be utilized. Another
commonly used method to handle the pumped water is the “sprinkler method,” which involves
applying the water to vegetated areas through a perforated discharge hose. Dispersal from a water
truck for dust control can also be used to disperse the pumped water.
4.0 Final Stabilization and Long-Term Stormwater Management
4.1 Final Stabilization
All disturbed areas will be seeded, crimped and mulched. Soil amendments such as compost, peat,
aged manure, or other similar materials, shall also be utilized. Soil amendments shall be tilled into
the soil to a minimum depth of 6”, and should comply with the requirements found in City Code
Section 12-132 (refer also to Land Use Code 3.8.21). As defined by the Colorado Department of
Public Health and Environment (CDPHE) in the General Permit Application for Stormwater
Discharges, “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, physical erosion reduction methods have been
employed.”
Table 2 - Native Grass Seed Mix
Preferred
Varieties
Seeded Rate
(lbs. per acre,
drilled)
PLS
Seeded/acre
Leymus Cinereus Great Basin Wilrye Mangar 3 285,000
Nassella Viridula Green Needlegrass Lodorm 2 362,000
Chnatherum Hymenoides Indian Ricegrass Paloma, Nezpar 1 188,000
Elymus Trachycaulus Slender Wheatgrass Primar, Revenue 2 320,000
Elymus Lanceolatus Thickspike Wheatgrass Critana 3 580,500
Pascopyrum Smithii Western Wheatgrass Arriba, Barton 4 504,000
Totals 15 2,239,500
Species
4.2 Long-Term Stormwater Management
The method of long-term stormwater management will take place at the Udall Natural Area water
quality facility. All disturbed areas will receive permanent paving or will be vegetated per the
Landscape Plan.
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5.0 Inspection, Maintenance and Record Keeping
5.1 BMP Inspection
All temporary erosion control facilities shall be inspected at a minimum of once every two (2) weeks
and after each significant storm event or snowmelt. Repairs or reconstruction of BMPs, as
necessary, shall occur as soon as possible in order to ensure the continued performance of their
intended function. It is the responsibility of the SWMP Administrator to conduct bi-weekly
inspections, maintain BMPs if needed, to keep records of site conditions and inspections, and to
update the SWMP as necessary.
The construction site perimeter, disturbed areas, all applicable/installed erosion and sediment
control measures, and areas used for material 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 SWMP shall be observed to ensure that they are
operating correctly. Particular attention should be paid to areas that have a significant potential for
stormwater pollution, such as demolition areas, concrete washout locations, and vehicle entries to
the site. The inspection must be documented to ensure compliance with the permit requirements.
5.2 BMP Maintenance
Any BMP’s not operating in accordance with the SWMP must be addressed as soon as possible,
immediately in most cases, to prevent the discharge of pollutants. If modifications are necessary,
such modifications shall be documented so that the SWMP accurately reflects on-site conditions.
The SWMP needs to accurately represent field conditions at all times.
Uncontrolled releases of mud, muddy water, or measurable amounts of sediment found off-site will
be recorded with a brief explanation of the measures taken to clean-up the sediment that has left
the site, as well as the measures taken to prevent future releases. This record shall be made
available to the appropriate public agencies (Colorado Department of Public Health and
Environment, Water Quality Control Division; Environmental Protection Agency; City of Fort Collins;
etc.) upon request.
Preventative maintenance of all temporary and permanent erosion control BMPs shall be provided
in order to ensure the continued performance of their intended function. Temporary erosion control
measures are to be removed after the site has been sufficiently stabilized as determined by the City
of Fort Collins. Maintenance activities and actions to correct problems shall be noted and recorded
during inspections.
Inspection and maintenance procedures specific to each BMP identified with this SWMP are
discussed in Section 3. Details have also been included with Appendix B.
5.3 Record Keeping
Documentation of site inspections must be maintained. The following items are to be recorded and
kept with the SWMP:
Date of Inspection
Name(s) and title(s) of personnel making the inspection
Location(s) of sediment discharges or other pollutants from the site
Location(s) of BMP’s that need to be maintained
Location(s) of BMP’s that failed to operate as designed or proved inadequate
Locations(s) where additional BMP’s are needed that were not in place at the time of inspection
Deviations from the minimum inspection schedule
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Descriptions of corrective action taken to remedy deficiencies that have been identified
The report shall contain a signed statement indicating the site is in compliance with the permit to the
best of the signer’s knowledge and belief after corrective actions have been taken.
Provided within Appendix E of this SWMP is an Example Inspection Log to aid in the record keeping
of BMP inspections and maintenance. Photographs, field notebooks, drawings and maps should be
included by the SWMP Administrator when appropriate.
In addition to the Inspection Log, records should be kept documenting:
BMP maintenance and operation
Stormwater contamination
Contacts with suppliers
Notes on the need for and performance of preventive maintenance and other repairs
Implementation of specific items in the SWMP
Training events (given or attended)
Events involving materials handling and storage
Contacts with regulatory agencies and personnel
Notes of employee activities, contact, notifications, etc.
Records of spills, leaks, or overflows that result in the discharge of pollutants must be documented
and maintained. A record of other spills that are responded to, even if they do not result in a
discharge of pollutants, should be made. Information that should be recorded for all occurrences
includes the time and date, weather conditions, reasons for the spill, etc. Some spills may need to
be reported to authorities immediately. Specifically, a release of any chemical, oil, petroleum
product, sewage, etc., which may enter waters of the State of Colorado (which include surface
water, ground water and dry gullies or storm sewers leading to surface water) must be reported to
the CDPHE.
Additionally, the “Dynamic Site Plan” is intended to be a “living” document where the SWMP
Administrator can hand write the location of BMPs as they are installed to appropriately reflect the
current site conditions. Also on the “Dynamic Site Plan” is a “Table of Construction Sequence and
BMP Application/Removal” that the SWMP Administrator can use to document when BMPs were
installed or removed in conjunction with construction activities. These items have been included as
an aid to the SWMP Administrator, and other methods of record keeping are at his or her discretion.
This Stormwater Management Plan (both the text and map) is not a static document. It
is a dynamic device intended to be kept current and logged as construction takes place.
It shall be the responsibility of the SWMP Administrator and/or the permit holder (or
applicant thereof) to ensure the plan is properly maintained and followed. Diligent
administration is critical, including processing the Notice to Proceed and noting on the
Stormwater Management Plan the dates that various construction activities occur and
respective BMPs are installed and/or removed.
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6.0 Additional SWMP and BMP Resources
Urban Drainage and Flood Control District
Urban Storm Drainage Criteria Manual - Volume 3 “Best Management Practices”
Colorado Department of Transportation
Erosion Control and Stormwater Quality Guide
BMP Field Academy
EPA Menu of BMP’s
Construction Site Storm Water Runoff Control
International Stormwater Best Management (BMP) Database
Rocky Mountain Education Center
Rocky Mountain Education Center
Red Rocks Community College, Lakewood
Keep It Clean Partnership
Boulder
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References
1. Final Drainage Report for Landmark Residences on Mountain Avenue, Northern
Engineering Services, April 29, 2014 (NE Project No. 1022-001)
2. Soil Resource Report for Larimer County Area, Colorado, Natural Resources
Conservation Service, United States Department of Agriculture.
3. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood
Control District, Water Resources Publications, LLC., Denver, Colorado, Updated
November 2010.
APPENDIX A
SITE MAPS
APPENDIX B
EROSION CONTROL DETAILS
APPENDIX C
LANDSCAPE PLAN
APPENDIX D
COPIES OF PERMITS/APPLICATIONS
APPENDIX E
INSPECTION LOGS
APPENDIX F
CONTRACTOR INSERTS
APPENDIX G
CONTRACTOR INSERTS