HomeMy WebLinkAboutBLD2006-00429 Stormwater Management r •
Stormwater Pollution Prevention Plan
And
Permanent Stormwater Control Plan
For
Wolfe Residence
Prepared For
Southwest Regional Office
300 Desmond Drive
Lacey, WA 98503
360-407-6300
Owner Developer P Operator/Contractor
J. Emmet Wolfe c/o
Zimmerman Architects
3091 Point White Drive
BI, WA 98110
APPROVED
STORMWATER PLAN
Project Site Location
363 Porter Lane, Port Townsend
SEP 2 2 2006
C rtified Erosion and Sediment Control Lead
JEFFERSON COUNTY
OEPT.OF COMMUNITY DE • OP. SWPPP Prepared By S
stcNnn;R.. Browne Engineering, Inc. .�. �o w'S�Q I
147 Finch Place SW, Suite 4 Q' ��
RECEIVED Bainbridge Island, WA 98110 y -4 "}'
(206) 842 0605 '",i) ' 3'3'7'9.5' ,40 ,<:/'5:1)4
A. Loving, Engineer
SWPPP Preparation Date "'is rvrONAL t X a
�ty
JEFFERSON Mr HC[ 3/31/06
EXPIRES 10/20/2ao7
Approximate Project Construction Dates 5/4/
7/2006-7/2007
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Contents
1.0 Introduction
1
2.0 Site Description
3
2.1 Existing Conditions
3
2.2 Proposed Site Development
3
3.0 Construction Stormwater BMPs
5
3.1 The 12 BMP Elements
5
3.1.1 Element#1 —Mark Clearing Limits
5
3.1.2 Element#2—Establish Construction Access
5
3.1.3 Element#3 —Control Flow Rates
5
3.1.4 Element#4—Install Sediment Controls
5
3.1.5 Element#5 —Stabilize Soils
6
3.1.6 Element#6—Protect Slopes
7
3.1.7 Element#7—Protect Drain Inlets
7
3.1.8 Element#8—Stabilize Channels and Outlets
7
3.1.9 Element#9— Control Pollutants
8
3.1.10 Element#10—Control Dewatering 8
3.1.11 Element#11 —Maintain BMPs
8
3.1.12 Element#12—Manage the Project
9
3.2 Site Specific BMPs
11
4.0 Construction Phasing and BMP Implementation
12
5.0 Pollution Prevention Team
13
5.1 Roles and Responsibilities
13
5.2 Team Members
14
6.0 Site Inspections and Monitoring
15
6.1 Site Inspection
15
6.1.1 Site Inspection Frequency
15
6.1.2 Site Inspection Documentation
16
6.2 Stormwater Quality Monitoring
16
6.2.1 Turbidity
16
6.2.2 pH
16
7.0 Reporting and Recordkeeping
17
7.1 Recordkeeping
17
7.1.1 Site Log Book
17
7.1.2 Records Retention
17
7.1.3 Access to Plans and Records
17
7.1.4 Updating the SWPPP
17
7.2 Reporting
18
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7.2.1 Discharge Monitoring Reports
18
7.2.2 Notification of Noncompliance
18
Appendix A—Site Plans
Appendix B —Construction BMPs
Appendix C—Alternative BMPs
Appendix D—Site Inspection Forms (and Site Log)
Appendix E—Engineering Calculations
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Storm water Pollution Prevention Plan
1.0 Introductio
n
This Stormwater Pollution Prevention Plan (SWPPP) has been prepared as part of the stormwater
permit requirements for the Wolfe Residence construction project in Jefferson County,
Washington. The site is located on the west side of Quimper Peninsula, west of the City of Port
Townsend. The construction of a single-family residence is proposed on this high-bank
waterfront parcel. A geotechnical report has also been prepared to assist in making development
recommendations for the site.
The purpose of this SWPPP is to describe the proposed construction activities and all temporary
and permanent erosion and sediment control (TESC)measures, pollution prevention measures,
inspection/monitoring activities, and recordkeeping that will be implemented during the
proposed construction project. The objectives of the SWPPP are to:
4. Implement Best Management Practices (BMPs) to prevent erosion and
sedimentation, and to identify, reduce, eliminate or prevent stormwater
contamination and water pollution from construction activity.
5. Prevent violations of surface water quality, ground water quality, or
sediment management standards.
6. Prevent, during the construction phase, adverse water quality impacts
including impacts on beneficial uses of the receiving water by controlling
peak flow rates and volumes of stormwater runoff at the Permittee's
outfalls and downstream of the outfalls.
This SWPPP was prepared using the Ecology SWPPP Template downloaded from the Ecology
website on July 2, 2005. This SWPPP was prepared based on the requirements set forth in the
Construction Stormwater General Permit,Stormwater Management Manual for Western
Washington (SWMMWW 2005) and in the Stormwater Management Manual for Eastern
Washington (SWMMEW 2004). The report is divided into seven main sections with several
appendices that include stormwater related reference materials. The topics presented in the each
of the main sections are:
• Section 1 —INTRODUCTION. This section provides a summary
description of the project, and the organization of the SWPPP document.
• Section 2 —SITE DESCRIPTION. This section provides a detailed
description of the existing site conditions,proposed construction activities,
and calculated stormwater flow rates for existing conditions and post—
construction conditions.
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Storm water Pollution Prevention Plan
• Section 3 — CONSTRUCTION BMPs. This section provides a detailed
description of the BMPs to be implemented based on the 12 required
elements of the SWPPP (SWMMEW 2004).
• Section 4— CONSTRUCTION PHASING AND BMP
IMPLEMENTATION. This section provides a description of the timing
of the BMP implementation in relation to the.project schedule.
• Section 5 —POLLUTION PREVENTION TEAM. This section identifies
the appropriate contact names (emergency and non-emergency),
monitoring personnel, and the onsite temporary erosion and sedimentation
control inspector
• Section 6—INSPECTION AND MONITORING. This section provides a
description of the inspection and monitoring requirements such as the
parameters of concern to be monitored, sample locations, sample
frequencies, and sampling methods for all stormwater discharge locations
from the site.
• Section 7—RECORDKEEPING. This section describes the requirements
for documentation of the BMP implementation, site inspections,
monitoring results, and changes to the implementation of certain BMPs
due to site factors experienced during construction.
Supporting documentation and standard forms are provided in the following Appendices:
Appendix A— Site plans
Appendix B— Construction BMPs
Appendix C—Alternative Construction BMP list
Appendix D—General Permit
Appendix E— Site Log and Inspection Forms
Appendix F—Engineering Calculations
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Stormwater Pollution Prevention Plan
2.0 Site Description
2.1 Existing Conditions
The proposed site is located west of Port Townsend, Washington. A site vicinity map is
provided in Appendix A. The site is 3.15 acres in size and is currently undeveloped. The
topography of the site and surrounding properties slope to the northwest. The Strait of Juan de
Fuca borders the northern property line. A steep bluff, approximately 100 feet high, is located
above the Strait. Loose, weathered glacial outwash is present across the site at depths of 2 to 3
feet. Loose outwash is underlain by dense glacial outwash. In addition, very loose colluvium is
located along the bluff face.
Runoff from the site generally drains from southeast to northwest as overland flow. No springs
or seeps were observed along the bluff or the upland portion of the site.
The site is mapped within a landslide hazard area buffer and required a geotechnical report.
Shannon & Wilson prepared a report dated March 21, 2006.
2.2 Proposed Site Development
The proposed development includes the construction of a single-story single-family residence.
The proposed building will be centrally located on the northern portion of the site. A detached
garage, paths, and gravel driveway will also be constructed. Stormwater will be collected and
piped directly to the base of the bluff. Runoff from the driveway will be treated with a
stormwater catch basin insert for water quality treatment. Porter Lane divides the property into
approximately equivalent northern and southern portions. The southern portion will remain
largely undeveloped. A new drainfield, new well, and electrical and telecommunication services
will also be constructed to serve the single-family residence.
Construction activities will include site preparation, TESC installation, excavation for the
building foundations,poured concrete foundations, grading for the building pads, construction of
the residence and associated utilities, and construction completion. The schedule and phasing of
BMPs during construction is provided in Section 4.0.
Stormwater runoff volumes were calculated using the Western Washington Hydrology Model
(WWHM). All stormwater will be collected and discharged to the base of the bluff, above the
Ordinary High Water Mark.
After the building is constructed and all new utilities are installed, the site will be graded and
landscaped.
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Stormwater Pollution Prevention Plan
The following summarizes details regarding site areas:
• Total parcel area: 3.15 acres
• Total development area: 0.21 acres
• Percent impervious area before construction: • 1.1%
• Percent impervious area after construction: 6.1 %
• Disturbed area during construction: 0.21 acres
• Disturbed area that is characterized as impervious (i.e.,
access roads, staging, parking): 0.16 acres
• 2-year stormwater runoff peak flow prior to construction
(existing): 0.0 cfs
• 10-year stormwater runoff peak flow prior to construction
(existing): 0.0 cfs
• 2-year stormwater runoff peak flow during construction: 0.035 cfs
• 10-year stormwater runoff peak flow during construction: 0.050 cfs
• 2-year stormwater runoff peak flow after construction: 0.035 cfs
• 10-year stormwater runoff peak flow after construction: 0.050 cfs
All stormwater flow calculations are provided in Appendix F.
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3.0 Construction Stormwater BM Ps
3.1 The 12 BMP Elements
Alternate BMPs are included in Appendix C as a quick reference tool for the onsite inspector in
the event the BMP(s) listed above are deemed ineffective or inappropriate during construction to
satisfy the requirements set forth in the General NPDES Permit (Appendix D). To avoid
potential erosion and sediment control issues, the Certified Erosion and Sediment Control Lead
will promptly initiate the implementation of one or more of the alternative BMPs listed in
Appendix C after the first sign that existing BMPs are ineffective or failing.
3.1.1 Element#1 —Mark Clearing Limits
To protect adjacent properties and to reduce the area of soil exposed to construction, the limits of
construction will be clearly marked before land-disturbing activities begin. Trees that are to be
preserved, as well as all sensitive areas and their buffers, shall be clearly delineated, both in the
field and on the plans. In general, natural vegetation and native topsoil shall be retained in an
undisturbed state to the maximum extent possible. The BMPs relevant to marking the clearing
limits that will be applied for this project include:
• Preserving Natural Vegetation (BMP C 101)
• Buffer Zones (BMP C 102)
3.1.2 Element#2 —Establish Construction Access
Construction access or activities occurring on unpaved areas shall be minimized, yet where
necessary, access points shall be stabilized to minimize the tracking of sediment onto public
roads, and wheel washing, street sweeping, and street cleaning shall be employed to prevent
sediment from entering state waters. All wash wastewater shall be controlled on site. The
specific BMPs related to establishing construction access that will be used on this project
include:
• Stabilized Construction Entrance (BMP C105)
3.1.3 Element#3 — Control Flow Rates
No flow control is proposed for this site. All stormwater discharges from the site will be piped
to the base of the bluff, i.e. Direct Discharge.
3.1.4 Element#4—Install Sediment Controls
All stormwater runoff from disturbed areas shall pass through an appropriate sediment removal
BMP before leaving the construction site or prior to being discharged to an infiltration facility.
The specific BMPs to be used for controlling sediment on this project include:
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Storm water Pollution Prevention Plan
• Silt Fence (BMP C233)
• Vegetated Strip (BMP C234)
Whenever possible, sediment laden water shall be discharged into onsite, relatively level,
vegetated areas (BMP C240 paragraph 5, page 4-102). -
In some cases, sediment discharge in concentrated runoff can be controlled using permanent
stormwater BMPs (e.g., infiltration swales, ponds, trenches). Sediment loads can limit the
effectiveness of some permanent stormwater BMPs, such as those used for infiltration or
biofiltration; however, those BMPs designed to remove solids by settling (wet ponds or detention
ponds) can be used during the construction phase. When permanent stormwater BMPs will be
used to control sediment discharge during construction, the structure will be protected from
excessive sedimentation with adequate erosion and sediment control BMPs. Any accumulated
sediment shall be removed after construction is complete and the permanent stormwater BMP
will be restabilized with vegetation per applicable design requirements once the remainder of the
site has been stabilized.
The following BMPs may be implemented as end-of-pipe sediment controls as required to meet
permitted turbidity limits in the site discharge(s). Prior to the implementation of these
technologies, sediment sources and erosion control and soil stabilization BMP efforts will be
maximized to reduce the need for end-of-pipe sedimentation controls.
• Temporary Sediment Pond (BMP C241)
• Construction Stormwater Filtration (BMP C251)
• Construction Stormwater Chemical Treatment(BMP C 250)
(implemented only with prior written approval from Ecology).
3.1.5 Element#5—Stabilize Soils
Exposed and unworked soils shall be stabilized with the application of effective BMPs to prevent
erosion throughout the life of the project. The specific BMPs for soil stabilization that shall be
used on this project include:
• Temporary and Permanent Seeding(BMP C120)
• Mulching(BMP C121)
The project site is located west of the Cascade Mountain Crest. As such, no soils shall remain
exposed and unworked for more than 7 days during the dry season (May 1 to September 30) and
2 days during the wet season (October 1 to April 30). Regardless of the time of year, all soils
shall be stabilized at the end of the shift before a holiday or weekend if needed based on weather
forecasts.
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Storm water Pollution Prevention Plan
In general, cut and fill slopes will be stabilized as soon as possible and soil stockpiles will be
temporarily covered with plastic sheeting. All stockpiled soils shall be stabilized from erosion,
protected with sediment trapping measures, and where possible, be located away from storm
drain inlets, waterways, and drainage channels.
3.1.6 Element #6—Protect Slopes
All cut and fill slopes will be designed, constructed, and protected in a manner than minimizes
erosion. The following specific BMPs will be used to protect slopes for this project:
• Temporary and Permanent Seeding(BMP C 120)
• Grass-Lined Channels (BMP C201)
3.1.7 Element#7—Protect Drain Inlets
All storm drain inlets and culverts made operable during construction shall be protected to
prevent unfiltered or untreated water from entering the drainage conveyance system. However,
the first priority is to keep all access roads clean of sediment and keep street wash water separate
from entering storm drains until treatment can be provided. Storm Drain Inlet Protection (BMP
C220) will be implemented for all drainage inlets and culverts that could potentially be impacted
by sediment-laden runoff on and near the project site. The following inlet protection measures
will be applied on this project:
• Catch Basin Filters
If the BMP options listed above are deemed ineffective or inappropriate during construction, or
if no BMPs are listed above but deemed necessary during construction, the Certified Erosion and
Sediment Control Lead shall implement one or more of the alternative BMP inlet protection
options listed in Appendix C.
3.1.8 Element#8—Stabilize Channels and Outlets
Where site runoff is to be conveyed in channels, or discharged to a stream or some other natural
drainage point, efforts will be taken to prevent downstream erosion. The specific BMPs for
channel and outlet stabilization that shall be used on this project include:
• A diffusion tee will be installed on the outlet of the stormwater outfall pipe.
The project site is located west of the Cascade Mountain Crest. As such, all temporary on-site
conveyance channels shall be designed, constructed, and stabilized to prevent erosion from the
expected peak 10 minute velocity of flow from a Type 1A, 10-year, 24-hour recurrence interval
storm for the developed condition. Alternatively, the 10-year, 1-hour peak flow rate indicated by
an approved continuous runoff simulation model, increased by a factor of 1.6, shall be used.
Stabilization, including armoring material, adequate to prevent erosion of outlets, adjacent
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Stormwater Pollution Prevention Plan
streambanks, slopes, and downstream reaches shall be provided at the outlets of all conveyance
systems.
3.1.9 Element #9— Control Pollutants
All pollutants, including waste materials and demolition debris, that occur onsite shall be
handled and disposed of in a manner that does not cause contamination of stormwater. Good
housekeeping and preventative measures will be taken to ensure that the site will be kept clean,
well organized, and free of debris. If required, BMPs to be implemented to control specific
sources of pollutants are discussed below.
Vehicles, construction equipment, and/or petroleum product storage/dispensing:
• All vehicles, equipment, and petroleum product storage/dispensing areas
will be inspected regularly to detect any leaks or spills, and to identify
maintenance needs to prevent leaks or spills.
• On-site fueling tanks and petroleum product storage containers shall
include secondary containment.
• Spill prevention measures, such as drip pans, will be used when
conducting maintenance and repair of vehicles or equipment.
• In order to perform emergency repairs on site, temporary plastic will be
placed beneath and, if raining, over the vehicle.
• Contaminated surfaces shall be cleaned immediately following any
discharge or spill incident.
Concrete and grout:
• Process water and slurry resulting from concrete work will be prevented
from entering the waters of the State by implementing Concrete Handling
measures (BMP C151).
The facility does not require a Spill Prevention, Control, and Countermeasure (SPCC) Plan under
the Federal regulations of the Clean Water Act (CWA).
3.1.10 Element#10—Control Dewatering
No dewatering is proposed as part of this construction project.
3.1.11 Element#11 — Maintain BMPs
All temporary and permanent erosion and sediment control BMPs shall be maintained and
repaired as needed to assure continued performance of their intended function. Maintenance and
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repair shall be conducted in accordance with each particular BMP's specifications. Visual
monitoring of the BMPs will be conducted at least once every calendar week and within 24 hours
of any rainfall event that causes a discharge from the site. If the site becomes inactive, and is
temporarily stabilized, the inspection frequency will be reduced to once every month.
All temporary erosion and sediment control BMPs shall be removed within 30 days after the
final site stabilization is achieved or after the temporary BMPs are no longer needed. Trapped
sediment shall be removed or stabilized on site. Disturbed soil resulting from removal of BMPs
or vegetation shall be permanently stabilized.
3.1.12 Element#12—Manage the Project
Erosion and sediment control BMPs for this project have been designed based on the following
• g
Design the project to fit the existing topography, soils, and drainage
patterns.
• Emphasize erosion control rather than sediment control.
• Minimize the extent and duration of the area exposed.
• Keep runoff velocities low.
• Retain sediment on site.
• Thoroughly monitor site and maintain all ESC measures.
• Schedule major earthwork during the dry season.
In addition, project management will incorporate the key components listed below:
As this project site is located west of the Cascade Mountain Crest, the project will be managed
according to the following key project components:
Phasing of Construction
• The construction project is being phased to the extent practicable in order
to prevent soil erosion, and, to the maximum extent possible, the transport
of sediment from the site during construction.
• Revegetation of exposed areas and maintenance of that vegetation shall be
an integral part-of the clearing activities during each phase of construction,
per the Scheduling BMP (C 162).
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Seasonal Work Limitations
' From October 1 through April 30, clearing, grading, and other soil
disturbing activities shall only be permitted if shown to the satisfaction of
the local permitting authority that silt-laden runoff will be prevented from
leaving the site through a combination of-the following:
❑ Site conditions including existing vegetative coverage, slope, soil
type, and proximity to receiving waters; and
❑ Limitations on activities and the extent of disturbed areas; and
❑ Proposed erosion and sediment control measures.
' Based on the information provided and/or local weather conditions, the
local permitting authority may expand or restrict the seasonal limitation on
site disturbance.
• The following activities are exempt from the seasonal clearingand
limitations: grading
❑ Routine maintenance and necessary repair of erosion and sediment
control BMPs;
❑ Routine maintenance of public facilities or existing utility
structures that do not expose the soil or result in the removal of the
vegetative cover to soil; and
❑ Activities where there is 100 percent infiltration of surface water
runoff within the site in approved and installed erosion and
sediment control facilities.
Coordination with Utilities and Other Jurisdictions
' Care has been taken to coordinate with utilities, other construction
projects, and the local jurisdiction in preparing this SWPPP and
scheduling the construction work.
Inspection and Monitoring
' All BMPs shall be inspected, maintained, and repaired as needed to assure
continued performance of their intended function. Site inspections shall
be conducted by a person who is knowledgeable in the principles and
practices of erosion and sediment control. This person has the necessary
skills to:
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❑ Assess the site conditions and construction activities that could
impact the quality of stormwater, and
O Assess the effectiveness of erosion and sediment control measures
used to control the quality of stormwater discharges.
• A Certified Erosion and Sediment Control Lead shall be on-site or on-call
at all times.
• Whenever inspection and/or monitoring reveals that the BMPs identified
in this SWPPP are inadequate, due to the actual discharge of or potential
to discharge a significant amount of any pollutant, appropriate BMPs or
design changes shall be implemented as soon as possible.
Maintaining an Updated Construction SWPPP
• This SWPPP shall be retained on-site or within reasonable access to the
site.
• The SWPPP shall be modified whenever there is a change in the design,
construction, operation, or maintenance at the construction site that has, or
could have, a significant effect on the discharge of pollutants to waters of
the state.
• The SWPPP shall be modified if, during inspections or investigations
conducted by the owner/operator, or the applicable local or state
regulatory authority, it is determined that the SWPPP is ineffective in
eliminating or significantly minimizing pollutants in stormwater
discharges from the site. The SWPPP shall be modified as necessary to
include additional or modified BMPs designed to correct problems
identified. Revisions to the SWPPP shall be completed within seven (7)
days following the inspection.
3.2 Site Specific BMPs
Site specific BMPs are shown on the TESC Plan Sheets and Details. These site specific plan
sheets will be updated as necessary.
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4.0 Construction Phasing and BMP
Implementation
The BMP implementation schedule will be driven by the construction schedule. The following
provides a sequential list of the proposed construction schedule milestones and the corresponding
BMP implementation schedule. The list contains key milestones such as wet season
construction.
The BMP implementation schedule listed below is keyed to proposed phases of the construction
project, and reflects differences in BMP installations and inspections that relate to wet season
construction. The project site is located west of the Cascade Mountain Crest. As such, the dry
season is considered to be from May 1 to September 30 and the wet season is considered to be
from October 1 to April 30.
• Install stabilized construction entrance: 7/02/06
• Install Silt Fence: 7/02/06
• Begin clearing and grading activities: 7/3/06
• Prepare concrete footings: 8/1/06
• Construct permanent stormwater controls: 8/15/06
• Prepare Seeding and Mulching: 9/30/06
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5.0 Pollution Prevention Team
5.1 Roles and Responsibilities
The pollution prevention team consists of personnel responsible for implementation of the
SWPPP, including the following:
• Certified Erosion and Sediment Control Lead (CESCL)—primary
contractor contact, responsible for site inspections (BMPs, visual
monitoring, sampling, etc.); to be called upon in case of failure of any
ESC measures.
• Resident Engineer—For projects with engineered structures only
(sediment ponds/traps, sand filters, etc.): site representative for the owner
that is the project's supervising engineer responsible for inspections and
issuing instructions and drawings to the contractor's site supervisor or
representative
• Emergency Ecology Contact—individual to be contacted at Ecology in
case of emergency.
• Emergency Owner Contact—individual that is the site owner or
representative of the site owner to be contacted in the case of an
emergency.
• Non-Emergency Ecology Contact—individual that is the site owner or
representative of the site owner than can be contacted if required.
• Monitoring Personnel—personnel responsible for conducting water
quality monitoring; for most sites this person is also the Certified Erosion
and Sediment Control Lead.
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5.2 Team Members
Names and contact information for those identified as members of the pollution prevention team
are provided in the following table.
Title Name(s) Phone Number
Certified Erosion and Sediment Control Lead(CESCL)
Resident Engineer A. Loving 206-842-0605
Emergency Ecology Contact
Emergency Owner Contact
Non-Emergency Ecology Contact
Monitoring Personnel
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6.0 Site Inspections and Monitoring
Monitoring includes visual inspection, monitoring for water quality parameters of concern, and
documentation of the inspection and monitoring findings in a site log book. A site log book will
be maintained for all on-site construction activities and will include:
• A record of the implementation of the SWPPP and other permit
requirements;
• Site inspections; and,
• Stormwater quality monitoring.
For convenience, the inspection form and water quality monitoring forms included in this
SWPPP include the required information for the site log book. This SWPPP may function as the
site log book if desired, or the forms may be separated and included in a separate site log book.
However, if separated, the site log book but must be maintained on-site or within reasonable
access to the site and be made available upon request to Ecology or the local jurisdiction.
6.1 Site Inspection
All BMPs will be inspected, maintained, and repaired as needed to assure continued performance
of their intended function. Site inspections will be conducted by a person who is knowledgeable
in the principles and practices of erosion and sediment control. The onsite inspector will have
the skills to assess the potential for water quality impacts as a result of the type of construction
activities occurring on site, and the knowledge of the appropriate and effective ESC measures
needed to control the quality of stormwater discharges.
Site inspection will occur in all areas disturbed by construction activities and at all stormwater
discharge points. Stormwater will be examined for the presence of suspended sediment,
turbidity, discoloration, and oily sheen. The site inspector will evaluate and document the
effectiveness of the installed BMPs and determine if it is necessary to repair or replace any of the
BMPs to improve the quality of stormwater discharges. All maintenance and repairs will be
documented in the site log book or forms provided in this document. All new BMPs or design
changes will be documented in the SWPPP as soon as possible.
6.1.1 Site Inspection Frequency
Site inspections will be conducted at least once a week and within 24 hours following any
rainfall event which causes a discharge of stormwater from the site. For sites with temporary
stabilization measures, the site inspection frequency can be reduced to once every month.
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6.1.2 Site Inspection Documentation
The site inspector will record each site inspection using the site log inspection forms provided in
Appendix E. The site inspection log forms may be separated from this SWPPP document,but
will be maintained on-site or within reasonable access to the site and be made available upon
request to Ecology or the local jurisdiction.
6.2 Stormwater Quality Monitoring
The construction site is less than one acre in size, and does not discharge to an impaired water
body, and is therefore not subject to the general water quality monitoring requirements.
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7.0 Reporting and Recordkeeping
7.1 Recordkeeping
7.1.1 Site Log Book
A site log book will be maintained for all on-site construction activities and will include:
• A record of the implementation of the SWPPP and other permit
requirements;
• Site inspections; and,
• Stormwater quality monitoring.
For convenience, the inspection form and water quality monitoring forms included in this
SWPPP include the required information for the site log book.
7.1.2 Records Retention
Records of all monitoring information (site log book, inspection reports/checklists, etc.), this
Stormwater Pollution Prevention Plan, and any other documentation of compliance with permit
requirements will be retained during the life of the construction project and for a minimum of
three years following the termination of permit coverage in accordance with permit condition
S5.C.
7.1.3 Access to Plans and Records
The SWPPP, General Permit, Notice of Authorization letter, and Site Log Book will be retained
on site or within reasonable access to the site and will be made immediately available upon
request to Ecology or the local jurisdiction. A copy of this SWPPP will be provided to Ecology
within 14 days of receipt of a written request for the SWPPP from Ecology. Any other
information requested by Ecology will be submitted within a reasonable time. A copy of the
SWPPP or access to the SWPPP will be provided to the public when requested in writing in
accordance with permit condition S5.G.
7.1.4 Updating the SWPPP
In accordance with Conditions S3, S4.B, and S9.B.3 of the General Permit, this SWPPP will be
modified if the SWPPP is ineffective in eliminating or significantly minimizing pollutants in
stormwater discharges from the site or there has been a change in design, construction, operation,
or maintenance at the site that has a significant effect on the discharge, or potential for discharge,
of pollutants to the waters of the State. The SWPPP will be modified within seven days of
determination based on inspection(s) that additional or modified BMPs are necessary to correct
problems identified, and an updated timeline for BMP implementation will be prepared.
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7.2 Reporting
7.2.1 Discharge Monitoring Reports
Discharge Monitoring Report (DMR) forms \\i 11 not be submitted to Ecology because water
quality sampling is not being proposed at the site.
7.2.2 Notification of Noncompliance
If any of the terms and conditions of the permit are not met, and it causes a threat to human
health or the environment, the following steps will be taken in accordance with permit section
S5.F:
1. Ecology will be immediately notified of the failure to comply.
2. Immediate action will be taken to control the noncompliance issue and to
correct the problem. If applicable, sampling and analysis of any
noncompliance will be repeated immediately and the results submitted to
Ecology within five (5) days o f becoming aware of the violation.
3. A detailed written report describing the noncompliance will be submitted
to Ecology within five (5) days, unless requested earlier by Ecology.
18
•
Storm water Pollution Prevention Plan
Appendix A — Site Plans
•
PROJECT
LOCATION
�GP ���e
�F e
\)PLO 4-7��
C9
/
FORT
A Rp
CAPE GEORGE ROAD CgpF GFO
RGF k 9p
VICINITY MAP
SCALE: 1"=1000'
JEFFERSON COUNTY, WASHINGTON
• �" •
\ W
♦
♦
♦
♦
♦ _
♦
♦
♦♦ TOP OF BLUFF
do
0
•
cs
♦
♦
7/: \\♦ 40' MIN.
/ • \ .
♦ n
W I
I C83
/ I TYPE 1
a II IE 147
II
z /7I
I FABRIC
y0
w
4.
F: I I
I♦ /t
• I I
I I I rI
I ;II
I \ �� 1.,
C82
TYPE 1 j Qp��//
IE 158 . I \
/-.
lc.
a
I t 66 N
to / ' r— +L_SD-
;;I
CBI t _( YARD -`'. .. `•.:.. :."
IE 173 ` 1 '.�t HOUSE'
^. FF EL178.-0
TOW 178.2
'. I FG 1:40 BOW 172.5
comae
. ...y0 tc1 BOW 178.0 0l
0
TRENCH L 1! i I [I 7: if
vlDRAIN f ►itils: . OW 184
180 �IP BOW 178.5
START WALL
'
180.0 /
��' 1, W
CONSTRUCTION f, oi 181.0 ij
ENTRANCE "F .r le
it.p:
i o
r`I' Uq / 60' ACCESS & UTR1T1
Sf //ti - /�' SPLIT RAIL
CnON I-`"1` i EASEMENT i/ FENCE
d' I,civ
WATER SERVICE '�%i C E.r' PROJECT BENCHMARK
UNE FROM � '�I `' ' ........„1‘ ELEV. 200.0
PRIVATE WELL li 4• ,J`-
-a' s'-
N � !
DRAINAGE MAP BRO VV .1\ E
SITE PLAN WOLFE RESIDENCE ENGINEERING INC
SCALE: 1"=200' PORT TOWNSEND WA 147 Finch Place,Suite 4
_/ Bainbridge Island,WA 98110
T(206)842-0605 F(206)780-9322
•
Storrater Pollution Prevention Plan
Appendix B — Construction BMPs
Preserving Natural Vegetation (BMP C101 )
Buffer Zones (BMP C 102) •
Stabilized Construction Entrance (BMP C 1 05)
Silt Fence (BMP C233)
Vegetated Strip (BMP C234)
Temporary and Permanent Seeding (BMP C120)
Mulching(BMP C121)
20
110 •
Storm water Pollution Prevention Plan
Appendix C — Alternative BMPs
The following includes a list of possible alternative BMPs for each of the 12 elements not
described in the main SWPPP text. This list can be referenced in the event a BMP for a specific
element is not functioning as designed and an alternative BMP needs to be implemented.
Element#1 -Mark Clearing Limits
BMP C103: High Visibility Plastic or Metal Fence
BMP C104: Stake and Wire Fence
Element#2 - Establish Construction Access
BMP C106: Wheel Wash
BMP C107: Construction Road/Parking Area Stabilization
Element#3 - Control Flow Rates
BMP C240: Sediment Trap
BMP C241: Temporary Sediment Pond
Element #4 - Install Sediment Controls
BMP C230: Straw Bale Barrier
BMP C231: Brush Barrier
BMP C232: Gravel Filter Berm
BMP C235: Straw Wattles
BMP C240: Sediment Trap
BMP C241: Temporary Sediment Pond
BMP C250: Construction Stormwater Chemical Treatment
BMP C251: Construction Stormwater Filtration
Advanced BMPs:
Element #5 - Stabilize Soils
BMP C 122: Nets and Blankets
BMP C123: Plastic Covering
BMP C 124: Sodding
BMP C 125: Topsoiling
BMP C130: Surface Roughening
BMP C 131: Gradient Terraces
BMP C 140: Dust Control
BMP C180: Small Project Construction Storrn water Pollution Prevention
Element #6 - Protect Slopes
BMP C130: Surrace Roughening
21
• •
Storm water Pollution Prevention Plan
BMP Cl31: Gradient Terraces
BMP C200: Interceptor Dike and Swale
BMP C204: Pipe Slope Drains
BMP C205: Subsurface Drains
BMP C207: Check Dams
Element#7— Protect Drain Inlets
Element #8 - Stabilize Channels and Outlets
BMP C202: Channel Lining
Element#10 - Control Dewatering
Additional Advanced BMPs to Control Dewatering:
22
Storgater Pollution Prevention Plan
Appendix D — Site Inspection Forms (and Site Log)
The results of each inspection shall be summarized in an inspection report or checklist
P
that is entered into or attached to the site log book. It is suggested that the inspection
report or checklist be included in this appendix to keep monitoring and inspection
information in one document, but this is optional. However, it is mandatory that this
SWPPP and the site inspection forms be kept onsite at all times during construction, and
that inspections be performed and documented as outlined below.
At a minimum, each inspection report or checklist shall include:
a. Inspection date/times
b. Weather information: general conditions during inspection,
approximate amount of precipitation since the last inspection,
and approximate amount of precipitation within the last 24 hours.
c. A summary or list of all BMPs that have been implemented,
including observations of all erosion/sediment control structures or
practices.
d. The following shall be noted:
i. locations of BMPs inspected,
ii. locations of BMPs that need maintenance,
iii. the reason maintenance is needed,
iv. locations of BMPs that failed to operate as designed or
intended, and
v. locations where additional or different BMPs are needed, and
the reason(s)why
e. A description of stormwater discharged from the site. The presence
of suspended sediment, turbid water, discoloration, and/or oil
sheen shall be noted, as applicable.
f. A description of any water quality monitoring performed during
inspection, and the results of that monitoring.
g. General comments and notes, including a brief description of any
BMP repairs, maintenance or installations made as a result of the
inspection.
h. A statement that, in the judgment of the person conducting the site
inspection, the site is either in compliance or out of compliance
with the terms and conditions of the SWPPP and the NP[)[:S
permit. If the site inspection indicates that the site is out of
23
III
Stormilk Pollution Prevention Plan
compliance, the inspection report shall include a summary of the
remedial actions required to bring the site back into compliance, as
well as a schedule of implementation.
i. Name, title, and signature of person conducting the site inspection;
and the following statement: "I certify under penalty of law that
this report is true, accurate, and complete, to the best of my
knowledge and belief'.
When the site inspection indicates that the site is not in compliance with any terms and
conditions of the NPDES permit, the Permittee shall take immediate action(s) to: stop,
contain, and clean up the unauthorized discharges, or otherwise stop the noncompliance;
correct the problem(s); implement appropriate Best Management Practices (BMPs),
and/or conduct maintenance of existing BMPs; and achieve compliance with all
applicable standards and permit conditions. In addition, if the noncompliance causes a
threat to human health or the environment, the Permittee shall comply with the
Noncompliance Notification requirements in Special Condition S5.F of the permit.
II
24
• Stwater Pollution Prevention Plan
Site Inspection Form
General Information
Project Name:
Inspector Name: Title:
CESCL# :
Date:
Time:
Inspection Type: ❑ After a rain event
❑ Weekly
❑ Turbidity/transparency benchmark exceedance
o Other
Weather
Precipitation Since last inspection In last 24 hours
Description of General Site Conditions:
Inspection of BMPs
Element 1: Mark Clearing Limits
BMP:
Location Inspected Functioning
Y N I Y N NIP Problem/Corrective Action
BMP:
Location Inspected Functioning
y N I Y N , Problem/Corrective Action
Element 2: Establish Construction Access
BMP:
Location Inspected Functioning
y N I Y N NIP Problem/Corrective Action
BMP:
Location Inspected Functioning
Y N Y N NIP Problem/Correcti ve Action
25
r Stormw.Pollution Prevention Plan
Element 3: Control Flow Rates
BMP:
Location Inspected Functioning
Y N I Y N NIP Problem/Corrective Action
BMP:
Location Inspected Functioning
Y N I Y N NIPProblem/Corrective Action
Element 4: Install Sediment Controls
BMP:
Location Inspected Functioning
Y N I Y N NIP Problem/Correchve Action
BMP:
Location Inspected Functioning
Y N I Y N NIP Problem/Corrective Action
BMP:
Location Inspected Functioning
Y N I Y N NIPProblem/Corrective Action
BMP:
Location Inspected Functioning
N NIP Problem/Corrective Action
I, N I I,
BMP:
Location Inspected Functioning
Problem/Corrective Action
Y N I Y N NIP
26
• Stcwater Pollution Prevention Plan
Element 5: Stabilize Soils
BMP:
Location Inspected Functioning
Problem/Corrective Action
Y N I Y N NIP
BMP:
Location Inspected Functioning
Y N I Y N NIP Problem/Corrective Action
BMP:
Location Inspected Functioning
Y N I Y N NIP Problem/Corrective Action
BMP:
Location Inspected Functioning
Y N I Y N NIP Problem/Corrective Action
Element 6: Protect Slopes
BMP:
Location Inspected Functioning
Y N I Y N NIP Problem/Corrective Action
BMP:
Location Inspected Functioning
Y N I Y N NIP Problem/Corrective Action
BMP:
Location Inspected Functioning
Y N I Y N NIP Problem/Corrective Action
27
0 Stormw110Pollution Prevention Plan
Element 7: Protect Drain Inlets
BMP:
Location Inspected Functioning
Y N I Y N NIP Problem/Corrective Action
BMP:
Location Inspected Functioning
Y N Y N NIP Problem/Corrective Action
BMP:
Location Inspected Functioning
Y N Y N NIP Problem/Corrective Action
Element 8: Stabilize Channels and Outlets
BMP:
Location Inspected Functioning
Y N Y N NIP Problem/Corrective Action
BMP:
Location Inspected Functioning
Y N Y N NIP Problem/Corrective Action
BMP:
Location Inspected Functioning
Y N Y N NIP Problem/Corrective Action
BMP:
Location Inspected Functioning
Y N I Y N NIP Problem/Corrective Action
1
28
Storrter Pollution Prevention Plan
Element 9: Control Pollutants
BMP:
Location Inspected Functioning Problem/Corrective Action
Y N Y N NIP
BMP:
Location Inspected Functioning Problem/Corrective Action
Y N Y N NIP
Element 10: Control Dewatering
BMP:
Location Inspected Functioning Problem/Corrective Action
Y N Y N NIP
BMP:
Location Inspected Functioning Problem/Corrective Action
Y N Y N NIP
BMP:
Location Inspected Functioning Problem/Corrective Action
Y N Y N NIP
29
• Stormwr ollution Prevention Plan
Stormwater Discharges From the Site
Observed? Problem/Corrective Action
Y N
Location
Turbidity
Discoloration
Sheen _
Location
Turbidity
Discoloration
Sheen
30
• Stor•3ter Pollution Prevention Plan
Water Quality Monitoring
Was any water quality monitoring conducted? ❑ Yes ❑ No
If water quality monitoring was conducted, record results here:
•
If water quality monitoring indicated turbidity 250 NTU or greater; or transparency 6
cm or less, was Ecology notified by phone within 24 hrs?
o Yes ❑ No
If Ecology was notified, indicate the date, time, contact name and phone number
below:
Date:
Time:
Contact Name:
Phone #:
General Comments and Notes
Include BMP repairs, maintenance, or installations made as a result of the inspection.
Were Photos Taken? o Yes ❑ No
If photos taken, describe photos below:
31
• Stormw Pollution Prevention Plan
Appendix E — Engineering Calculations
>>
WESTERN WASHINGTO HYDROLOGY MODEL V2
PROJE�REPORT411
Project Name: default
Site Address: 363 PORTER LANE
City PORT TOWNSEND
Report Date : 4/3/2006
Gage Port Angelis
Data Start 1948
Data End 1993
(adjusted) Precip Scale: 0.80
PREDEVELOPED LAND USE
Basin PRE
Flows To Point of Compliance
GroundWater: No
Land Use Acres
OUTWASH FOREST: 3 . 15
DEVELOPED LAND USE
RCHRES (POND) INFORMATION
ANALYSIS RESULTS
Flow Frequency Return Periods for Predeveloped
Return Period Flow(cfs)
2 year 0.00047
5 year 0.000597
10 year 0.000653
25 year 0 .000702
50 year 0.000728
100 year 0.000747
Flow Frequency Return Periods for Developed Unmitigated
Return Period Flow(cfs)
2 year 0.035146
5 year 0.0444
10 year 0. 05017
25 year 0. 057151
50 year 0.062169
100 year 0. 067058
Flow Frequency Return Periods for Developed Mitigated
Return Period Flow(cfs)
2 year 0
5 year 0
10 year 0
25 year 0
50 year 0
100 year 0
Tk:AR FLOW(cis)
100 .0672 t 10 U t :.,.•.;ti.c• rt
50 .0623 - - i'' •' W
25 .0573 - ._ _ 1�
1N
10 .0503 i11 1.0
• I d
co
5 .0446 I Ii 1111
b. o Redeveloped
0353 j
� i I' _ l$$l (r Ili_ .2 10E-1 - x t3e�.eloped)Mitigated
`, �' f I T 1�` I :D'� 1 l N 0000 00 00 0 0 0
1 1 ll �, 0 o t c��enKs:,cric rn�
i t 1 ,
10E-2
1 10 20 30 40 50 60 78 20 90 99
Cumulative Probability
Yearly Peaks for Predeveloped Flow Frequency Chart
TEAR FLOW(Cfs)
100'.0671 0.06 o -redeuetoped
y
50 .0622 ; ; 1 ,I i' ( •i!( ! I!I! ;<Developed IAA Facility
25 '.0572 • 1 1 j; l 1�I mill ( 1 �� 0.05
i i 1j ( Rio 0
10 .0502 ! i 1 1 I 1 i o i l? i I( y 0.04
5 .0444 • I I'1 I' l I r" j ' i '. 0.03
ti t' ! J. off P 1o! I
2 0351 1 , ti i �j f' I r i'l . to 0.02
\11
�'��� 1 11 1 i 1 , 11 1 i ail I i 46
tl f, 1;1�i Ilt I1 .�, to
l,i, i;i i };1 I'1 I 10E-5 3 10E-4 10E-3 10E-2 10E-1 1 10
Percent Exceeding
Yearly Peaks for developed W/O Pond Duration Graph
TEAR FLOW(efs)
160 .0000 «-+oa_,cr.0 rc,sw .,-.A.,�M. »ai .a38‹ a..,- 7.,_.r
Yearly Peaks for Developed W/Pond
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• Critical Depth •
Worksheet for Circular Channel
Project Description
Project File untitled.fm2
Worksheet CIRCULAR
Flow Element Circular Channel
Method Manning's Formula
Solve For Channel Depth
Input Data
Mannings Coefficient 0.009
Channel Slope 0.020000 ft/ft
Diameter 6.00 in
Discharge 0.07 cfs
Results
Depth 0.08 ft
Flow Area 0.02 ft2
Wetted Perimeter 0.42 ft
Top Width 0.37 ft
Critical Depth 0.13 ft a1c.
Percent Full 16.76
Critical Slope 0.003402 ft/ft
Velocity 3.23 ft/s
Velocity Head 0.16 ft
Specific Energy 0.25 ft
Froude Number 2.36
Maximum Discharge 1.23 cfs
Full Flow Capacity 1.15 cfs
Full Flow Slope 0.000075 ft/ft
Flow is supercritical.
FIowM,a,ter v5.15
03:33:1804/04/06 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203)755-1666 Page 1 of 1