HomeMy WebLinkAboutRS_SWPPP_170316_v1Construction Stormwater General Permit
Stormwater Pollution Prevention Plan
(SWPPP)
for
Allura at Tiffany Park
Prepared for:
The Washington State Department of Ecology
Northwest Region, Bellevue
Permittee / Owner Developer Operator / Contractor
Mainvue WA, LLC Mainvue WA, LLC To be Determined
S.E. 18th Street and 124th Pl S.E. Renton, WA
Certified Erosion and Sediment Control Lead (CESCL)
Name Organization Contact Phone Number
To be Determined To be Determined To be Determined
SWPPP Prepared By
Name Organization Contact Phone Number
Barry Talkington Barghausen Consulting
Engineers, Inc.
(425) 251-6222
SWPPP Preparation Date
March 16, 2017
Project Construction Dates
Activity / Phase Start Date End Date
To be Determined April 1, 2017 December 31, 2020
RECEIVED
03/20/2017 Ann Fowler
DEVELOPMENT ENGINEERING DIVISION
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Table of Contents
1 Project Information ................................................................................................................. 4
1.1 Existing Conditions ......................................................................................................... 5
1.2 Proposed Construction Activities .................................................................................... 6
2 Construction Stormwater Best Management Practices (BMPs) ............................................ 8
2.1 The 12 Elements ............................................................................................................ 8
2.1.1 Element 1: Preserve Vegetation / Mark Clearing Limits .......................................... 8
2.1.2 Element 2: Establish Construction Access .............................................................. 9
2.1.3 Element 3: Control Flow Rates .............................................................................. 10
2.1.4 Element 4: Install Sediment Controls .................................................................... 11
2.1.5 Element 5: Stabilize Soils ...................................................................................... 12
2.1.6 Element 6: Protect Slopes ..................................................................................... 14
2.1.7 Element 7: Protect Drain Inlets .............................................................................. 15
2.1.8 Element 8: Stabilize Channels and Outlets ........................................................... 16
2.1.9 Element 9: Control Pollutants ................................................................................ 17
2.1.10 Element 10: Control Dewatering ........................................................................... 24
2.1.11 Element 11: Maintain BMPs .................................................................................. 25
2.1.12 Element 12: Manage the Project ........................................................................... 26
3 Pollution Prevention Team ................................................................................................... 29
4 Monitoring and Sampling Requirements .............................................................................. 30
4.1 Site Inspection .............................................................................................................. 30
4.2 Stormwater Quality Sampling ....................................................................................... 30
4.2.1 Turbidity Sampling ................................................................................................. 30
4.2.2 pH Sampling .......................................................................................................... 32
5 Discharges to 303(d) or Total Maximum Daily Load (TMDL) Waterbodies ......................... 33
5.1 303(d) Listed Waterbodies ........................................................................................... 33
5.2 TMDL Waterbodies ....................................................................................................... 33
6 Reporting and Record Keeping ........................................................................................... 34
6.1 Record Keeping ............................................................................................................ 34
6.1.1 Site Log Book ........................................................................................................ 34
6.1.2 Records Retention ................................................................................................. 34
6.1.3 Updating the SWPPP ............................................................................................ 34
6.2 Reporting ...................................................................................................................... 35
6.2.1 Discharge Monitoring Reports ............................................................................... 35
6.2.2 Notification of Noncompliance ............................................................................... 35
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List of Tables
Table 1 – Summary of Site Pollutant Constituents .................................................................. 6
Table 2 – Pollutants .................................................................................................................. 17
Table 3 – pH-Modifying Sources ............................................................................................. 23
Table 4 – Dewatering BMPs ..................................................................................................... 24
Table 5 – Management .............................................................................................................. 26
Table 6 – BMP Implementation Schedule ............................................................................... 27
Table 7 – Team Information ..................................................................................................... 29
Table 8 – Turbidity Sampling Method ..................................................................................... 30
Table 9 – pH Sampling Method ................................................................................................ 32
List of Appendices
Appendix/Glossary
A. Site Map
B. BMP Detail
C. Correspondence
D. Site Inspection Form
E. Construction Stormwater General Permit (CSWGP)
F. 303(d) List Waterbodies / TMDL Waterbodies Information
G. Contaminated Site Information
H. Engineering Calculations
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List of Acronyms and Abbreviations
Acronym / Abbreviation Explanation
303(d) Section of the Clean Water Act pertaining to Impaired Waterbodies
BFO Bellingham Field Office of the Department of Ecology
BMP(s) Best Management Practice(s)
CESCL Certified Erosion and Sediment Control Lead
CO2 Carbon Dioxide
CRO Central Regional Office of the Department of Ecology
CSWGP Construction Stormwater General Permit
CWA Clean Water Act
DMR Discharge Monitoring Report
DO Dissolved Oxygen
Ecology Washington State Department of Ecology
EPA United States Environmental Protection Agency
ERO Eastern Regional Office of the Department of Ecology
ERTS Environmental Report Tracking System
ESC Erosion and Sediment Control
GULD General Use Level Designation
NPDES National Pollutant Discharge Elimination System
NTU Nephelometric Turbidity Units
NWRO Northwest Regional Office of the Department of Ecology
pH Power of Hydrogen
RCW Revised Code of Washington
SPCC Spill Prevention, Control, and Countermeasure
su Standard Units
SWMMEW Stormwater Management Manual for Eastern Washington
SWMMWW Stormwater Management Manual for Western Washington
SWPPP Stormwater Pollution Prevention Plan
TESC Temporary Erosion and Sediment Control
SWRO Southwest Regional Office of the Department of Ecology
TMDL Total Maximum Daily Load
VFO Vancouver Field Office of the Department of Ecology
WAC Washington Administrative Code
WSDOT Washington Department of Transportation
WWHM Western Washington Hydrology Model
Tab 1.0
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1 Project Information
This Stormwater Pollution Prevention Plan (SWPPP) has been prepared per the requirements
of the Washington State NPDES Construction Stormwater General Permit Conditions of
Approval for the Allura at Tiffany park project in The City of Renton, Washington. The proposed
Plat of Reserve at Tiffany Park is a single-family residential project consisting of 94 lots zoned
R8. The project is 21.66 acres in size containing four tax parcels (212305-9044, 212305-9051,
212305-9054, and 212305-9061). The site is located at the dead end of S.E. 18th Street near
the intersection of Monroe Avenue S.E. in a portion of Section 21, Township 23 North, Range 5
East, W.M., in the City of Renton.
The site is polygonal in shape and ties into two existing road stubs. The first is located in the
northwest corner of the site at the dead-end of S.E. 18th Street. The second road stub is
located to the southwest of the site on the southern side of the Cedar River Pipeline at the
dead-end of 124th Place S.E. These road stubs are to be tied into and will be extended into the
site to provide public access and circulation. This site is undeveloped and is currently zoned
R8; with a majority of the site being composed of second-growth forest. The elevations of the
site range from 456 to 398. There are four wetlands located on site; three of them are Category
2, with one Category 3.
The site is entirely surrounded by existing single family residences. Along the east property line
is the Mercer Island Pipe Line R/W. Along the south boundary is the Cedar River Pipeline R/W.
Access to the site from 124th Place S.E required the developer to an access easement through
the Cedar River Pipeline R/W.
On-site soils are mapped as mostly Alderwood, with a small portion along the southern
boundary mapped as Arents. Please refer to the Soils Map in this section. All drainage
calculations were modeled as till soils.
The project will be constructing roadways consisting of curb and gutter, sidewalk, and street
trees. The site will tie into the existing roads at the dead-ends of S.E. 18th Street and 124th
Place S.E. All roads for this project have been designed to be 26 feet wide, with an 8-foot
planter strip at the back of curb and a 5-foot sidewalk (both sides). Overall the proposed public
right-of-way is to be 53 feet in width.
The topography on site is gentle and rolling. The site generally slopes from east to west from
elevation 456 to 398. The project will be mass graded with cuts and fills balanced on-site. The
wetland areas will remain undisturbed along with portions of their buffers. Buffer averaging is
proposed. Other portions of the site will remain undisturbed in an effort to preserve as many
existing trees as possible.
The drainage facilities are required to meet the requirements of the 2009 King County Surface
Water Design Manual (KCSWDM) and the 2010 City of Renton Amendments to the KCSWDM.
The drainage design shall meet at a minimum the Conservation Flow Control and Basic Water
Quality Treatment. The drainage facility located in Tract A is a detention pond sized for Level 2
Flow Control. Water quality will be met by the use of a StormFilter for this project. The project
will be discharging the drainage from the pond to the existing drainage system within S.E. 18th
Street near the intersection of Lake Youngs Way SE.
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Construction activities will include demolition, clearing & grading, roadwork, detention vault
construction, StormFilter installation, stormwater conveyance installation, utilities installation,
foundation excavation, home construction, driveway & patio construction, and landscaping.
Construction is scheduled to begin on April 1, 2017 and estimated to be completed on
December 31, 2022. 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:
1. Implement Best Management Practices (BMPs) to prevent erosion and sediment,
and to identify, reduce, eliminate or prevent stormwater contamination and water
pollution from construction activity.
2. Prevent violations of surface water quality, ground water quality, or sediment
management standards.
3. During the construction phase prevent adverse water quality impacts including,
impacts of 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 January 1, 2016. The Template has been revised to incorporate all items in the
General NPDES Permit as well as provide more project specific BMPs that will be utilized
onsite. This SWPPP was prepared based on the requirements set forth in the Construction
Stormwater General Permit, Stormwater Management Manual for Western Washington
(SWMMWW 2012). The site project information for the site is summarized below.
Project/Site Name: Allura at Tiffany Park
Street/Location: the dead end of S.E. 18th Street near the
intersection of Monroe Avenue S.E.
City: Renton State: WA Zip code: 98058
Subdivision: Tiffany Park
Receiving waterbody: Ginger Creek
1.1 Existing Conditions
As previously mentioned, the total site area is approximately 21.66 acres in size. The site is
currently unoccupied with no existing structures on site. The site is mostly composed of
second-growth forest. The site generally slopes from east to west from elevation 456 to 398.
There are four wetlands located on site; three of them are Category 2, with one Category 3.
Based on the USDA Soils Map the site and surrounding area consist of Alderwood soils. The
site is entirely surrounded by existing single family residences. Along the east property line is
the Mercer Island Pipe Line R/W. Along the south boundary is the Cedar River Pipeline R/W.
Generally, surface water runoff for the site flows in an westerly direction. In order to maintain
existing site hydrology a detention vault will be used to control flow rates. Runoff will be treated
for water quality by a StormFilter and released to the existing storm system at Lake Youngs
Way S.E. the existing 18-inch concrete pipe turns south and conveys stormwater to the
entrance of Tiffany Park Elementary. At this point runoff enters a detention system underneath
the parking lot of the school and is discharged into a 60-inch diameter trunk line which
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eventually discharged to the Headwaters of Ginger Creek. A site vicinity map is provided in
Appendix A. The following summarizes the details of the existing site conditions:
Total acreage: 21.66
Disturbed acreage: 18.06
Existing structures: None
Landscape
topography:
Forested / Vegetated
Drainage patterns: Runoff flows in an westerly fassion to the neighbouring properties
Existing Vegetation: Alderwood Soils w/ regional trees and shrubs
Critical Areas (wetlands, streams, high erosion
risk, steep or difficult to stabilize slopes):
Three Category 2 Wetlands and one
Category 3 Wetland
List of known impairments for 303(d) listed or Total Maximum Daily Load (TMDL) for the
receiving waterbody: None
Table 1 includes a list of suspected and/or known contaminants associated with the construction
activity.
Table 1 – Summary of Site Pollutant Constituents
Constituent
(Pollutant) Location Depth Concentration
N/A N/A N/A N/A
1.2 Proposed Construction Activities
The site will be cleared according to the T.E.S.C. and Grading Plans. The permanent
stormwater facility will be built according to the Road and Drainage Plans. The proposed
development includes site development and eventual home construction of 94 residential lots
for single family residences and roadways. A system of pipes and catch basins will be installed
to convey stormwater runoff from the developed site and any onsite contributing basin areas to
the Detention and Water Quality facility located in Tract A. The facility in this tract has been
design to provide the required water quality and detain the storm water for a 100-year storm
event.
The site will be constructed in two phases, the Site Development Phase and the Vertical
Construction Phase.
The site development construction phase includes the following activities: Clearing & Grubbing,
Demolition, Sediment Pond, Mass Grading/Site Grading, Infrastructure (utilities, curb and gutter,
sidewalks, drives, etc.), and paving operations.
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Lot areas with flat pads are being created for the vertical construction phase to take place upon.
The vertical construction phase includes the following activities: Landscape and Irrigation, Home
Construction/Vertical, and Final Stabilization. The proposed residences will be located on Lots 1
through 94. Each lot will have an accompanying driveway, patio, walkways, and typical
residential landscaping.
In the developed condition stormwater runoff will be routed the onsite detention pond in Tract A.
The facility in this tract has been design to provide the required water quality and detention rates
for a 100-year storm event.
In the developed condition the site will be mostly developed. All nonimpervious surfaces will be
vegetated with a variety of local shrubs and grass.
Contaminated Site Information:
There are no activities that will result in the contamination of soil and or groundwater planned for
the site during clearing, grading, and/or the construction of the single family residences.
Tab 2.0
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2 Construction Stormwater Best Management Practices (BMPs)
The following sections describe BMPs that will be utilized during the construction of the project.
Alternate BMPs for the 12 BMP Elements may be implemented on a need by need basis,
should the 12 Elements below be deemed ineffective or inappropriate during the construction to
satisfy the requirements set forth in the General NPDES Permit. To avoid potential erosion and
sediment control issues that may cause violation(s) of the NPDES Construction Stormwater
permit, the Certified Erosion and Sediment Control Lead will promptly initiate the implementation
of one or more alternate BMPs after the first sign that existing BMPs are ineffective or failing.
The SWPPP is a living document reflecting current conditions and changes throughout the life
of the project. These changes may be informal (i.e., hand-written notes and deletions). Update
the SWPPP when the CESCL has noted a deficiency in BMPs or deviation from original design.
2.1 The 12 Elements
2.1.1 Element 1: Preserve Vegetation / Mark Clearing Limits
18.06 acres of the site are to be developed and mass graded to balance cut and fills. 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 top shall be retained in an
undisturbed state to the maximum extent possible. The BMP relevant to marking the clearing
limits that will be applied for this project include the following:
List and describe BMPs:
• High Visibility Fence (BMP C103)
Install colored orange fence to protect areas that are not to be disturbed, and mark trees
to be preserved.
• Silt Fence (BMP C233)
Silt fencing shall be used to control sediment flow offsite throughout the construction
process.
Installation Schedules: All BMPs to preserve vegetation and mark clearing limits are to be
installed prior to clearing and grading
Inspection and Maintenance plan: All fencing is to be inspected at the end of each day's work
and repaired if found to noncompliant with BMP specifications
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Responsible Staff: Certified Erosion and Sediment Control Lead
2.1.2 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. Street sweeping and street cleaning shall be employed where necessary to prevent
sediment from entering state waters. All wash wastewater shall be controlled onsite. The
specific BMPs related to establishing construction access hat will be used on this project are as
follows:
List and describe BMPs:
• Stabilized Construction Entrance (BMP C105)
One quarry spall construction entrance will be placed at the dead end of 124th PL SE,
near the proposed entrance to the site. This stabilized construction entrance will be used
to minimize the amount of sediment transported off site onto the existing roadway by
construction traffic.
• Construction Road/Parking Area Stabilization (BMP C107)
Proposed roads shall be stabilized immediately after grading to reduce erosion by
construction traffic or surface water runoff. During vertical construction, apply quarry
spall base on drive approaches for buildings lot/pad access or in other high traffic areas
such as material equipment storage and concrete washout areas.
• Concrete Washout Area (BMP C154)
Conduct washout off-site, or perform on-site concrete washout in a designated area.
This is done to prevent pollutants from entering surface or ground water
If sediment is tracked off site, clean the affected roadway thoroughly at the end of each day or
more frequently, as necessary. Remove sediment from roads by shoveling, sweeping, or pickup
and transport of the sediment to a controlled sediment disposal area.
Conduct street washing only after sediment removal in accordance with special condition
S9.D.2.d. Control street wash wastewater by pumping back on site or otherwise preventing it
from discharging off site into catch basins, stormwater conveyance systems, creek, or rivers that
connect to waters of the State.
Installation Schedules: Installation schedule to be determined by the General Contractor
Inspection and Maintenance plan: Inspection and maintenance is to take place at the end of
each day's work.
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Responsible Staff: Certified Erosion and Sediment Control Lead
2.1.3 Element 3: Control Flow Rates
In order to protect the properties and waterways downstream of the project site, stormwater
discharges from the site will be controlled. The Specific BMPs for the flow control that shall be
used on this project include the following:
Will you construct stormwater retention and/or detention facilities?
Yes No
Will you use permanent infiltration ponds or other low impact development (example: rain
gardens, bio-retention, porous pavement) to control flow during construction?
Yes No
List and describe BMPs:
• Temporary Sediment Pond (BMP C241)
The contractor shall size and constructed temporary sediment ponds located on the
proposed lots 2-3, 74-75 and 92-93, or other approved locations. A temporary outfall
shall discharge runoff to the existing closed drainage system located within SE 18th
Street and used during construction to mitigate onside runoff. The permanent drainage
facility may be used once it is completed
The project site is located west of the Cascade Mountain Crest. As a result, the project must
comply with the Minimum Requirement 7 (Ecology 2012). Minimum Requirement 7 states that
projects must provide flow control to reduce the impacts of stormwater runoff from impervious
surfaces and land cover conversions.
Essentially, discharge rates of stormwater from the site will be controlled where increases in
impervious area or soil compaction during construction could lead to downstream erosion, or
where necessary to meet local agency stormwater discharge requirements (e.g. discharge to
combined sewer systems).
Installation Schedules: Installation schedule to be determined by the General Contractor
Inspection and Maintenance plan: Inspection and maintenance is to take place at the end of
each day's work.
Responsible Staff: Certified Erosion and Sediment Control Lead
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2.1.4 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 discharge to a detention facility. The
specific BMPs to be used for controlling sediment on this project are as follows:
List and describe BMPs:
• Silt Fence (BMP C233)
During site development phase, silt fence will be used along the downhill perimeter of
the project to prevent sediment from leaving the site.
During the homebuilding phase, sediment control will not be necessary on all lots prior to
disturbance, as many are flat with well established grass cover. Temporary stabilized
lots with slope, or less well established grass cover will be inspected during wet weather
conditions and, if required, silt fence may be used as a sediment control. Before
removing vegetation on the lots, silt fence will be installed as a sediment control behind
curb.
• Storm Drain Inlet Protection (BMP C220)
Catch basins and storm drain inlets within the project boundary and downstream will
have an approved from of inlet protection installed. This will prevent coarse sediment
from entering the drainage system prior to permanent stabilization of the disturbed
draining area.
In additions, sediment will be removed from paved areas in and adjacent to construction
work areas manually or using a mechanical sweepers, as needed to minimize tracking of
sediments on vehicle tires away from the site and to minimize the transmission of
sediments from adjacent streets in runoff
The following BMPs will be implemented as end-of-pipe sediment controls as required to meet
permitted turbidity limits in the sit discharge(s). Prior to the implementation of these methods,
sediment sources and erosion control and soil stabilization BMP efforts will be maximized to
reduce the need for end-of-pipe sediment controls.
• Temporary Sediment Pond (BMP C241)
• Construction Stormwater Filtration (BMP C251)
• Construction Stormwater Chemical Treatment (BMP C250) (Implemented only with prior
written approval from Ecology.)
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Implement BMP C250/251 above end-of-pipe measures only if sediment sources and
erosion control and soil stabilization BMP efforts are not sufficient to reduce
sedimentation.
Installation Schedules: Installation schedule to be determined by the General Contractor
Inspection and Maintenance plan: Inspection and maintenance is to take place at the end of
each day's work.
Responsible Staff: Certified Erosion and Sediment Control Lead
2.1.5 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 in this project are as follows:
West of the Cascade Mountains Crest
Season Dates Number of Days Soils Can
be Left Exposed
During the Dry Season May 1 – September 30 7 days
During the Wet Season October 1 – April 30 2 days
Soils must be stabilized at the end of the shift before a holiday or weekend if needed based on
the weather forecast.
Anticipated project dates: Start date: April 1, 2017 End date: December 31, 2022
Will you construct during the wet season?
Yes No
List and describe BMPs:
• Temporary and Permanent Seeding (BMP C120)
Following final or fine grading activity in the rear and side yards, permanent seeding
shall be placed on exposed soil to provide permanent erosion protection.
• Mulching (BMP C121)
During the site development phase, mulching will be used for areas that will be
unworked for more than 2 days. Temporary seeding will be applied to areas that will be
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unworked for more than 7 days. During the home building phase, the construction area
will be significantly stabilized through well established grass cover. Proposed driveways
will receive base course materials as described under Element #2 above. Areas cleared
for building foundations or utility and irrigation placement will be temporarily stabilized by
one of the following methods which are based on the period exposed soils are left
unworked:
o If exposed soils are left unworked for more than 7 days during the dry season
and 2 days during the wet season but less than 30 days, mulching shall be
applied.
o If exposed soils are left unworked for more than 30 days, temporary or
permanent seeding shall be applied.
• Nets and Blankets (BMP C122)
Once final or fine grading activity has been completed, install Jute Matting on slopes
prior to planting.
• Sodding (BMP C124)
Following final or fine grading activity in the front yard, sod shall be placed on exposed
soil to provide permanent and immediate erosion protection.
• Plastic Covering (BMP C123)
• Topsoiling (BMP C125)
Utilize stockpile management during all phases of construction per BMP. Cover
stockpiles with plastic covering to prevent erosion during rain events.
• Wattles (BMP C235)
Install wattles downslope of newly landscaped areas to control sediment runoff until
stabilization.
Cement or Calcium Chloride may be used for soil stabilization and dewatering. See section
4.2.2 for pH Sampling Requirements.
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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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.
Installation Schedules: Installation schedule to be determined by the General Contractor
Inspection and Maintenance plan: Inspection and maintenance is to take place at the end of
each day's work.
Responsible Staff: Certified Erosion and Sediment Control Lead
2.1.6 Element 6: Protect Slopes
All cut and fill slopes will be designed, constructed, and protected in a manner that minimizes
erosion. The following specific BMPs will be used to protect slopes for this project:
West of the Cascade Mountains Crest
Describe how slopes will be designed, constructed, and protected to minimize erosion.
Temporary pipe slope drains must handle the peak 10-minute flow rate from a Type 1A,
10-year, 24-hour frequency storm for the developed condition. Alternatively, the 10-year, 1-hour
flow rate predicted by an approved continuous runoff model, increased by a factor of 1.6, may
be used.
The hydrologic analysis must use the existing land cover condition for predicting flow rates from
tributary areas outside the project limits.
For tributary areas on the project site, the analysis must use the temporary or permanent project
land cover condition, whichever will produce the highest flow rates.
If using the Western Washington Hydrology Model (WWHM) to predict flows, bare soil areas
should be modeled as “landscaped area”.
Describe how you will reduce scouring within constructed channels that are cut down a slope.
Will steep slopes be present at the site during construction?
Yes No
List and describe BMPs:
• Temporary and Permanent Seeding (BMP C120)
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The site is moderately sloped (less than 15%). Sloping areas will be treated as
described under Element 5 above.
Installation Schedules: Installation schedule to be determined by the General Contractor
Inspection and Maintenance plan: Inspection and maintenance is to take place at the end of
each day's work.
Responsible Staff: Certified Erosion and Sediment Control Lead
2.1.7 Element 7: Protect Drain Inlets
Drain inlets will be protected using the following BMP methods:
Describe how you will protect all operable storm drain inlets so that stormwater runoff does not
enter the stormwater conveyance system.
Describe how you will remove sediment that enters the stormwater conveyance system (i.e.,
filtration, treatment, etc.).
Keep in mind inlet protection may function well for coarse sediment but is less effective in
filtering finer particles and dissolved constituents. Inlet protection is the last component of a
treatment train and protection of drain inlets include additional sediment and erosion control
measures. Inlet protection devices will be cleaned (or removed and replaced), when sediment
has filled the device by one third (1/3) or as specified by the manufacturer.
Inlets will be inspected weekly at a minimum and daily during storm events.
List and describe BMPs:
• Storm Drain Inlet Protection (BMP C220)
Prior to construction, storm drain inlet protection will be utilized on all catch basins in the
roadway along the frontage of any areas receiving stormwater from construction
activities within the permitted area. Install inlet protection once permanent storm drain
inlets on site are constructed.
Installation Schedules: Installation schedule to be determined by the General Contractor
Inspection and Maintenance plan: Inspection and maintenance is to take place at the end of
each day's work.
Responsible Staff: Certified Erosion and Sediment Control Lead
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2.1.8 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 made to prevent downstream erosion. The specific BMPs
for channel and outlet stabilization that shall be used on this project include:
Describe how you will prevent downstream erosion where site runoff is to be conveyed in
channels, discharged to a stream or, discharged to a natural drainage point.
West of the Cascade Mountains Crest
On-site conveyance channels must handle the peak 10-minute flow rate from a Type 1A,
10-year, 24-hour frequency storm for the developed condition. Alternatively, the 10-year, 1-hour
flow rate predicted by an approved continuous runoff model, increased by a factor of 1.6, may
be used.
The hydrologic analysis must use the existing land cover condition for predicting flow rates from
tributary areas outside the project limits.
For tributary areas on the project site, the analysis must use the temporary or permanent project
land cover condition, whichever will produce the highest flow rates.
If using the WWHM to predict flows, bare soil areas should be modeled as “landscaped area”.
Provide stabilization, including armoring material, adequate to prevent erosion of outlets,
adjacent stream banks, slopes, and downstream reaches, will be installed at the outlets of all
conveyance systems.
List and describe BMPs:
• Interceptor Dike and Swale (BMP C200)
During the site development phase, interceptor dikes and swales shall be constructed
down slope and on site of the construction site to convey stormwater to an erosion
control facility.
• Check Dams (BMP C207)
Check dams shall be used to reduce the velocity and energy of concentrated flow in
swales or ditches.
• Outlet Protection (BMP C209)
Outlet protection will be constructed at the outlet location of the storm drainage piping to prevent
erosion.
Page | 17 16055.021.doc
Installation Schedules: Installation schedule to be determined by the General Contractor
Inspection and Maintenance plan: Inspection and maintenance is to take place at the end of
each day's work.
Responsible Staff: Certified Erosion and Sediment Control Lead
2.1.9 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.
The following pollutants are anticipated to be present on-site:
Table 2 – Pollutants
Pollutant (List pollutants and source, if applicable)
Installation of sediment and erosion controls
Installation of stabilized exits
Vehicle tracking
Clearing and grubbing operations
Grading operations
Exposed soils and slopes
Import/export operations
Utility excavation operations
Landscapeing operations
Topsoil stripping and stockpiling
Fine grading of home sites
Vertical Construction
Concrete
List and describe BMPs:
Housekeeping BMPs
The following sections describe the controls, including storage practices to minimize exposure
of the materials to stormwater as well as spill prevention and response practices. 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.
Vehicles, construction equipment, and/or petroleum product storage/dispensing:
Page | 18 16055.021.doc
• 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. Secondary containment such as drip pans will be placed under
any leaking vehicles or equipment. All petroleum product storage containers will be
placed in secondary containment (see spill prevention and control below).
• 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 or when vehicle/equipment leaks are
observed.
• 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.
Chemical storage:
• Any chemicals stored in the construction areas will conform to the appropriate source
control BMPs listed in Volume IV of the Ecology stormwater manual. In Western WA, all
chemicals shall have cover, containment, and protection provided on site, per BMP
C153 for Material Delivery, Storage and Containment in SWMMWW 2012.
• Application of agricultural chemicals, including fertilizers and pesticides, shall be
conducted in a manner and at application rates that will not result in loss of chemical to
stormwater runoff. Manufacturers’ recommendations for application procedures and
rates shall be followed.
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) and
Sawcutting and Surfacing Pollution Prevention (BMP C152).
Sanitary wastewater:
• Proper sanitary and septic waste management are waste management and material
pollution controls that prevent the discharge of pollutants to stormwater from sanitary
and septic waste by providing convenient, well-maintained facilities, and arranging for
regular service and disposal. Implement as follows:
Page | 19 16055.021.doc
o Facilities should be located away from drainage facilities, watercourses, and from
traffic circulation.
o Provide a sufficient quantity of facilities to accommodate the workforce.
o Temporary sanitary facilities must be equipped with containment to prevent
discharge of pollutants to the stormwater drainage system of the receiving water.
o When subjected to high winds or risk of high winds, temporary sanitary facilities
should be secured to prevent overturning.
o Sanitary facilities should be located in a convenient location.
o Sanitary or septic wastes should be treated or disposed of in accordance with
state and local requirements.
o Sanitary facilities should be maintained in good working order by a licensed
service.
Solid and Liquid Waste:
• Solid and liquid waste generated during construction such as construction materials,
contaminated materials, and waste materials from maintenance activities will be
prevented from entering the waters of the State. Solid and liquid waste shall be handled
in accordance with BMPs for Storage of Liquid, Food Waste, or Dangerous Waste
Containers and BMPs for Loading and Unloading Areas for Liquid or Solid Materials.
o Solid waste will be stored in secure, clearly marked containers.
o Promptly contain and clean up solid and liquid pollutant leaks and spills including
oils, solvents, fuels, and dust from manufacturing operations on any exposed
soil, vegetation, or paved area.
o Sweep paved material handling and storage areas regularly as needed, for the
collection and disposal of dust and debris that could contaminate stormwater. Do
not hose down pollutants from any area to the ground, storm drain, conveyance
ditch, or receiving water unless necessary for dust control purposes to meet air
quality regulations.
Installation Schedules: The described BMPs will be implemented while all pollution generating
materials are onsite.
Inspection and Maintenance plan: Inspection and maintenance is to take place at the end of
each day's work.
Responsible Staff: Certified Erosion and Sediment Control Lead
Will maintenance, fueling, and/or repair of heavy equipment and vehicles occur on-site?
Yes No
If yes, describe spill prevention and control measures in place while conducting maintenance,
fueling, and repair of heavy equipment and vehicles.
Page | 20 16055.021.doc
If yes, also provide the total volume of fuel on-site and capacity of the secondary containment
for each fuel tank. Secondary containment structures shall be impervious.
List and describe BMPs:
Spill Prevention and Control BMPs
Prevent or reduce the discharge of pollutants to drainage systems or watercourses from leaks
and spills by reducing the chance for spills, stopping the source of spills, containing and
cleaning up spills, properly disposing of spill materials, and training employees. This best
management practice covers only spill prevention and control. However, Materials Delivery and
Storage (BMP C153), also contains useful information, particularly on spill prevention.
• To the extent that the work can be accomplished safely, spills of oil, petroleum products,
and substances listed under 40 CFR parts 110,117, and 302, and sanitary and septic
wastes should be contained and cleaned up immediately.
• Store hazardous materials and wastes in covered containers and protect from
vandalism.
• Place a stockpile of spill cleanup materials where it will be readily accessible.
• Train employees in spill prevention and cleanup.
• Designate responsible individuals to oversee and enforce control measures.
• Spills should be covered and protected from stormwater runon during rainfall to the
extent that it doesn’t compromise cleanup activities.
• Do not bury or wash spills with water.
• Store and dispose of used clean up materials, contaminated materials, and recovered
spill material that is no longer suitable for the intended purpose in conformance with the
provisions in applicable BMPs.
• Do not allow water used for cleaning and decontamination to enter storm drains or
watercourses. Collect and dispose of contaminated water in accordance WSDOE
regulations.
• Contain water overflow or minor water spillage and do not allow it to discharge into
drainage facilities or watercourses.
• Place proper storage, cleanup, and spill reporting instructions for hazardous materials
stored or used on the project site in an open, conspicuous, and accessible location.
• Keep waste storage areas clean, well organized, and equipped with ample clean
supplies as appropriate for the materials being stored. Perimeter controls, containment
structures, covers, and liners should be repaired or replaced as needed to maintain
proper function.
Cleanup:
• Clean up leaks and spills immediately.
• Use a rag for small spills on paved surfaces, a damp mop for general cleanup, and
absorbent material for larger spills. If the spilled material is hazardous, then the used
Page | 21 16055.021.doc
cleanup materials are also hazardous and must be sent to either a certified laundry
(rags) or disposed of as hazardous waste.
• Never hose down or bury dry material spills. Clean up as much of the material as
possible and dispose of properly.
• The spill kit should include, at a minimum:
o 1-Water Resistant Nylon Bag
o 3-Oil Absorbent Socks 3”x 4’
o 2-Oil Absorbent Socks 3”x 10’
o 12-Oil Absorbent Pads 17”x19”
o 1-Pair Splash Resistant Goggles
o 3-Pair Nitrile Gloves
o 10-Disposable Bags with Ties
o Instructions
• Spill kits will be located in areas with a high potential for spills and deployed in a manner
that allows rapid access and use by contractors. Some heavy equipment may have on-
board spill kits for small spills. Spill control kits will be inspected and inventoried each
construction season to confirm all required items are present. Spill control kits will be
inventoried after each emergency event and restocked as needed.
Minor Spills:
• Minor spills typically involve small quantities of oil, gasoline, paint, etc. which can be
controlled at the discovery of the spill.
• Contain the spread of the spill.
• Use absorbent materials on small spills rather than hosing down or burying the spill.
• Notify the project foreman immediately
• Recover spilled materials.
• Clean the contaminated area and properly dispose of contaminated materials.
• If the spill occurs on paved or impermeable surfaces, clean up using "dry" methods
(absorbent materials, cat litter and/or rags). Contain the spill by encircling with absorbent
materials and do not let the spill spread widely.
• If the spill occurs in dirt areas, immediately contain the spill by constructing an earthen
dike. Dig up and properly dispose of contaminated soil.
• If the spill occurs during rain, cover spill with tarps or other material to prevent
contaminating runoff.
Semi-Significant Spills:
• Semi-significant spills still can be controlled by the first responder along with the aid of
other personnel such as laborers and the foreman, etc. This response may require the
cessation of all other activities. Spills should be cleaned up immediately.
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Significant/Hazardous Spills
• For significant or hazardous spills that cannot be controlled by personnel in the
immediate vicinity, the following steps should be taken:
o Notify the local emergency response by dialing 911. In addition to 911, the
contractor will notify the proper City or County officials. All emergency phone
numbers will be posted at the construction site.
o Contact your Supervisor and the Divisional Environmental Manager. For spills of
federal reportable quantities, (examples are listed below) in conformance with the
requirements in 40 CFR parts 110,119, and 302, the Division Environmental
Manager (DEM) will notify the National Response Center at (800) 424-8802. The
DEM will notify the Department of Ecology and any other applicable agencies.
• The services of a spills contractor or a Haz-Mat team should be obtained immediately.
Construction personnel should not attempt to clean up until the appropriate and qualified
staffs have arrived at the job site.
• Notification should first be made by telephone and followed up with a written report.
Other agencies which may need to be consulted include, but are not limited to, the
Public Works Department, the Coast Guard, the Highway Patrol, the City/County Police
Department and Department of Ecology.
• Federal regulations require that any significant oil spill into a water body or onto an
adjoining shoreline be reported to the National Response Center (NRC) at 800-424-8802
(24 hours)
Installation Schedules: The described BMPs will be implemented while all pollution generating
materials are onsite.
Inspection and Maintenance plan: Inspection and maintenance is to take place at the end of
each day's work.
Responsible Staff: Certified Erosion and Sediment Control Lead
Will wheel wash or tire bath system BMPs be used during construction?
Yes No
If yes, provide disposal methods for wastewater generated by BMPs.
If discharging to the sanitary sewer, include the approval letter from your local sewer district
under Correspondence in Appendix C.
List and describe BMPs:
• Wheel Wash (BMP C106)
Page | 23 16055.021.doc
Discharge wheel wash or tire bath wastewater to a separate on-site treatment system that
prevents discharge to surface water, such as closed-loop recirculation or upland land
application, or to the sanitary sewer with local sewer district approval.
Installation Schedules: The described BMPs will be implemented while all pollution generating
materials are onsite.
Inspection and Maintenance plan: Inspection and maintenance is to take place at the end of
each day's work.
Responsible Staff: Certified Erosion and Sediment Control Lead
Will pH-modifying sources be present on-site?
Yes No If yes, check the source(s).
Table 3 – pH-Modifying Sources
None
Bulk cement
Cement kiln dust
Fly ash
Other cementitious materials
New concrete washing or curing waters
Waste streams generated from concrete grinding and sawing
Exposed aggregate processes
Dewatering concrete vaults
Concrete pumping and mixer washout waters
Recycled concrete
Other (i.e., calcium lignosulfate) [please describe: ]
Describe BMPs you will use to prevent pH-modifying sources from contaminating stormwater .
List and describe BMPs:
• pH Control for High pH Water (BMP C253)
• High pH Neutralization using CO2 (BMP C252) (Implemented only after notifying the local
Jurisdiction.)
• Sawcutting and Surfacing Pollution Prevention
Installation Schedules: The described BMPs will be implemented while all pollution generating
materials are onsite.
Inspection and Maintenance plan: Inspection and maintenance is to take place at the end of
each day's work.
Page | 24 16055.021.doc
Responsible Staff: Certified Erosion and Sediment Control Lead
Adjust pH of stormwater if outside the range of 6.5 to 8.5 su.
Obtain written approval from Ecology before using chemical treatment with the exception of CO2
or dry ice to modify pH.
Concrete trucks must not be washed out onto the ground, or into storm drains, open ditches,
streets, or streams. Excess concrete must not be dumped on-site, except in designated
concrete washout areas with appropriate BMPs installed.
2.1.10 Element 10: Control Dewatering
There will be no dewatering as part of this construction project.
Table 4 – Dewatering BMPs
Infiltration
Transport off-site in a vehicle (vacuum truck for legal disposal)
Ecology-approved on-site chemical treatment or other suitable treatment technologies
Sanitary or combined sewer discharge with local sewer district approval (last resort)
Use of sedimentation bag with discharge to ditch or swale (small volumes of localized
dewatering)
List and describe BMPs: None
Installation Schedules: None
Inspection and Maintenance plan: None
Responsible Staff: None
Page | 25 16055.021.doc
2.1.11 Element 11: Maintain BMPs
All temporary and permanent Erosion and Sediment Control (ESC) BMPs shall be maintained
and repaired as needed to ensure continued performance of their intended function.
Maintenance and repair shall be conducted in accordance with each particular BMP
specification (see Volume II of the SWMMWW or Chapter 7 of the SWMMEW).
Visual monitoring of all BMPs installed at the site will be conducted at least once every calendar
week and within 24 hours of any stormwater or non-stormwater discharge from the site. If the
site becomes inactive and is temporarily stabilized, the inspection frequency may be reduced to
once every calendar month.
All temporary ESC BMPs shall be removed within 30 days after final site stabilization is
achieved or after the temporary BMPs are no longer needed.
Trapped sediment shall be stabilized on-site or removed. Disturbed soil resulting from removal
of either BMPs or vegetation shall be permanently stabilized.
Additionally, protection must be provided for all BMPs installed for the permanent control of
stormwater from sediment and compaction. BMPs that are to remain in place following
completion of construction shall be examined and restored to full operating condition. If
sediment enters these BMPs during construction, the sediment shall be removed and the facility
shall be returned to conditions specified in the construction documents.
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2.1.12 Element 12: Manage the Project
The project will be managed based on the following principles:
• Projects will be phased to the maximum extent practicable and seasonal work limitations
will be taken into account.
• Inspection and monitoring:
o Inspection, maintenance and repair of all BMPs will occur as needed to ensure
performance of their intended function.
o Site inspections and monitoring will be conducted in accordance with Special
Condition S4 of the CSWGP. Sampling locations are indicated on the Site Map.
Sampling station(s) are located in accordance with applicable requirements of
the CSWGP.
• Maintain an updated SWPPP.
o The SWPPP will be updated, maintained, and implemented in accordance with
Special Conditions S3, S4, and S9 of the CSWGP.
As site work progresses the SWPPP will be modified routinely to reflect changing site
conditions. The SWPPP will be reviewed monthly to ensure the content is current.
Table 5 – Management
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
Other (please describe)
Page | 27 16055.021.doc
Optional: Fill out Table 6 by listing the BMP associated with specific construction activities.
Identify the phase of the project (if applicable). To increase awareness of seasonal
requirements, indicate if the activity falls within the wet or dry season.
Table 6 – BMP Implementation Schedule
Phase of Construction
Project
Stormwater BMPs Date Wet/Dry
Season
[Insert construction
activity]
[Insert BMP] [MM/DD/YYYY] [Insert
Season]
Page | 28 16055.021.doc
Phase of Construction
Project
Stormwater BMPs Date Wet/Dry
Season
[Insert construction
activity]
[Insert BMP] [MM/DD/YYYY] [Insert
Season]
Tab 3.0
Page | 29 16055.021.doc
3 Pollution Prevention Team
Table 7 – Team Information
Title Name(s) Phone Number
Certified Erosion and
Sediment Control Lead
(CESCL)
To be determined N/A
Resident Engineer Barry Talkington 425-251-6222
Emergency Ecology
Contact
To be determined N/A
Emergency Permittee/
Owner Contact
To be determined N/A
Non-Emergency Owner
Contact
To be determined N/A
Monitoring Personnel To be determined N/A
Ecology Regional Office 3190 160th Ave SE, Bellevue, WA (425) 649-7000
Tab 4.0
Page | 30 16055.021.doc
4 Monitoring and Sampling Requirements
Monitoring includes visual inspection, sampling for water quality parameters of concern, and
documentation of the inspection and sampling 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
• Stormwater sampling data
The site log book must be maintained on-site within reasonable access to the site and be made
available upon request to Ecology or the local jurisdiction.
Numeric effluent limits may be required for certain discharges to 303(d) listed waterbodies. See
CSWGP Special Condition S8 and Section 5 of this template.
4.1 Site Inspection
Site inspections will be conducted at least once every calendar week and within 24 hours
following any discharge from the site. For sites that are temporarily stabilized and inactive, the
required frequency is reduced to once per calendar month.
The discharge point(s) are indicated on the Site Map (see Appendix A) and in accordance with
the applicable requirements of the CSWGP.
4.2 Stormwater Quality Sampling
4.2.1 Turbidity Sampling
Requirements include calibrated turbidity meter or transparency tube to sample site discharges
for compliance with the CSWGP. Sampling will be conducted at all discharge points at least
once per calendar week.
Method for sampling turbidity:
Table 8 – Turbidity Sampling Method
Turbidity Meter/Turbidimeter (required for disturbances 5 acres or greater in size)
Transparency Tube (option for disturbances less than 1 acre and up to 5 acres in size)
The benchmark for turbidity value is 25 nephelometric turbidity units (NTU) and a transparency
less than 33 centimeters.
If the discharge’s turbidity is 26 to 249 NTU or the transparency is less than 33 cm but equal to
or greater than 6 cm, the following steps will be conducted:
1. Review the SWPPP for compliance with Special Condition S9. Make appropriate
revisions within 7 days of the date the discharge exceeded the benchmark.
Page | 31 16055.021.doc
2. Immediately begin the process to fully implement and maintain appropriate source
control and/or treatment BMPs as soon as possible. Address the problems within 10
days of the date the discharge exceeded the benchmark. If installation of necessary
treatment BMPs is not feasible within 10 days, Ecology may approve additional time
when the Permittee requests an extension within the initial 10-day response period.
3. Document BMP implementation and maintenance in the site log book.
If the turbidity exceeds 250 NTU or the transparency is 6 cm or less at any time, the following
steps will be conducted:
1. Telephone the applicable Ecology Region’s Environmental Report Tracking System
(ERTS) number within 24 hours.
• Central Region (Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan,
Yakima): (509) 575-2490
• Eastern Region (Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant,
Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, Whitman): (509) 329-3400
• Northwest Region (King, Kitsap, Island, San Juan, Skagit, Snohomish,
Whatcom): (425) 649-7000
• Southwest Region (Clallam, Clark, Cowlitz, Grays Harbor, Jefferson, Lewis,
Mason, Pacific, Pierce, Skamania, Thurston, Wahkiakum,): (360) 407-6300
2. Immediately begin the process to fully implement and maintain appropriate source
control and/or treatment BMPs as soon as possible. Address the problems within 10
days of the date the discharge exceeded the benchmark. If installation of necessary
treatment BMPs is not feasible within 10 days, Ecology may approve additional time
when the Permittee requests an extension within the initial 10-day response period
3. Document BMP implementation and maintenance in the site log book.
4. Continue to sample discharges daily until one of the following is true:
• Turbidity is 25 NTU (or lower).
• Transparency is 33 cm (or greater).
• Compliance with the water quality limit for turbidity is achieved.
o 1 - 5 NTU over background turbidity, if background is less than 50 NTU
o 1% - 10% over background turbidity, if background is 50 NTU or greater
• The discharge stops or is eliminated.
Page | 32 16055.021.doc
4.2.2 pH Sampling
pH monitoring is required for “Significant concrete work” (i.e., greater than 1000 cubic yards
poured or recycled concrete over the life of the project). The use of engineered soils (soil
amendments including but not limited to Portland cement-treated base [CTB], cement kiln dust
[CKD] or fly ash) also requires pH monitoring.
For significant concrete work, pH sampling will start the first day concrete is poured and
continue until it is cured, typically three (3) weeks after the last pour.
For engineered soils, pH sampling begins when engineered soils are first exposed to
precipitation and continues until the area is fully stabilized.
If the measured pH is 8.5 or greater, the following measures will be taken:
1. Prevent high pH water from entering storm sewer systems or surface water.
2. Adjust or neutralize the high pH water to the range of 6.5 to 8.5 su using appropriate
technology such as carbon dioxide (CO2) sparging (liquid or dry ice).
3. Written approval will be obtained from Ecology prior to the use of chemical treatment
other than CO2 sparging or dry ice.
Method for sampling pH:
Table 9 – pH Sampling Method
pH meter
pH test kit
Wide range pH indicator paper
Tab 5.0
Page | 33 16055.021.doc
5 Discharges to 303(d) or Total Maximum Daily Load (TMDL)
Waterbodies
5.1 303(d) Listed Waterbodies
Is the receiving water 303(d) (Category 5) listed for turbidity, fine sediment, phosphorus, or pH?
Yes No
List the impairment(s):
If yes, discharges must comply with applicable effluent limitations in S8.C and S8.D of the
CSWGP.
5.2 TMDL Waterbodies
Waste Load Allocation for CWSGP discharges:
Describe the method(s) for TMDL compliance:
List and describe BMPs:
Discharges to TMDL receiving waterbodies will meet in-stream water quality criteria at the point
of discharge.
The Construction Stormwater General Permit Proposed New Discharge to an Impaired Water
Body form is included in Appendix F.
Tab 6.0
Page | 34 16055.021.doc
6 Reporting and Record Keeping
6.1 Record Keeping
6.1.1 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
• Sample logs
6.1.2 Records Retention
Records will be retained during the life of the project and for a minimum of three (3) years
following the termination of permit coverage in accordance with Special Condition S5.C of the
CSWGP.
Permit documentation to be retained on-site:
• CSWGP
• Permit Coverage Letter
• SWPPP
• Site Log Book
Permit documentation will be provided within 14 days of receipt of a written request from
Ecology. A copy of the SWPPP or access to the SWPPP will be provided to the public when
requested in writing in accordance with Special Condition S5.G.2.b of the CSWGP.
6.1.3 Updating the SWPPP
The SWPPP will be modified if:
• Found ineffective in eliminating or significantly minimizing pollutants in stormwater
discharges from the site.
• There is a change in 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 will be modified within seven (7) days if inspection(s) or investigation(s) determine
additional or modified BMPs are necessary for compliance. An updated timeline for BMP
implementation will be prepared.
Page | 35 16055.021.doc
6.2 Reporting
6.2.1 Discharge Monitoring Reports
Cumulative soil disturbance is one (1) acre or larger; therefore, Discharge Monitoring
Reports (DMRs) will be submitted to Ecology monthly. If there was no discharge during a given
monitoring period the DMR will be submitted as required, reporting “No Discharge”. The DMR
due date is fifteen (15) days following the end of each calendar month.
DMRs will be reported online through Ecology’s WQWebDMR System.
To sign up for WQWebDMR go to:
http://www.ecy.wa.gov/programs/wq/permits/paris/webdmr.html
6.2.2 Notification of Noncompliance
If any of the terms and conditions of the permit is not met, and the resulting noncompliance may
cause a threat to human health or the environment, the following actions will be taken:
1. Ecology will be immediately notified of the failure to comply by calling the applicable
Regional office ERTS phone number (Regional office numbers listed below).
2. Immediate action will be taken to prevent the discharge/pollution or otherwise stop or
correct the noncompliance. If applicable, sampling and analysis of any noncompliance
will be repeated immediately and the results submitted to Ecology within five (5) days of
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.
Specific information to be included in the noncompliance report is found in Special Condition
S5.F.3 of the CSWGP.
Anytime turbidity sampling indicates turbidity is 250 NTUs or greater, or water transparency is 6
cm or less, the Ecology Regional office will be notified by phone within 24 hours of analysis as
required by Special Condition S5.A of the CSWGP.
• Central Region at (509) 575-2490 for Benton, Chelan, Douglas, Kittitas, Klickitat,
Okanogan, or Yakima County
• Eastern Region at (509) 329-3400 for Adams, Asotin, Columbia, Ferry, Franklin,
Garfield, Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, or Whitman
County
• Northwest Region at (425) 649-7000 for Island, King, Kitsap, San Juan, Skagit,
Snohomish, or Whatcom County
• Southwest Region at (360) 407-6300 for Clallam, Clark, Cowlitz, Grays Harbor,
Jefferson, Lewis, Mason, Pacific, Pierce, Skamania, Thurston, or Wahkiakum
Page | 36 16055.021.doc
Include the following information:
1. Your name and / Phone number
2. Permit number
3. City / County of project
4. Sample results
5. Date / Time of call
6. Date / Time of sample
7. Project name
In accordance with Special Condition S4.D.5.b of the CSWGP, the Ecology Regional office will
be notified if chemical treatment other than CO2 sparging is planned for adjustment of high pH
water.
Page | 37 16055.021.doc
Appendix/Glossary
A. Site Map
The site map must meet the requirements of Special Condition S9.E of the CSWGP
B. BMP Detail
Insert BMPs specification sheets here.
Download BMPs from the Ecology Construction Stormwater website at:
http://www.ecy.wa.gov/programs/wq/stormwater/construction/index.html
Select Resources and Guidance to find the links to the Stormwater Manuals.
C. Correspondence
Ecology
EPA
Local Government
D. Site Inspection Form
Create your own or download Ecology’s template:
http://www.ecy.wa.gov/programs/wq/stormwater/construction/index.html
Select Permit, Forms and Application to find the link to the Construction Stormwater
Site Inspection Form.
E. Construction Stormwater General Permit (CSWGP)
Download the CSWGP:
http://www.ecy.wa.gov/programs/wq/stormwater/construction/index.html
F. 303(d) List Waterbodies / TMDL Waterbodies Information
Proposed New Discharge to an Impaired Water Body form
SWPPP Addendum addressing impairment
G. Contaminated Site Information
Administrative Order
Sanitary Discharge Permit
Soil Management Plan
Soil and Groundwater Reports
Maps and Figures Depicting Contamination
H. Engineering Calculations
Exhibit A
Site Map
Exhibit B
BMP Detail
Exhibit C
Correspondence
Exhibit D
Site Inspection Form
Exhibit E
Construction Stormwater
General Permit (CSWGP)
Exhibit F
303(d) List Waterbodies/TMDL
Waterbodies Information
Exhibit G
Contaminated Site
Information
Exhibit H
Engineering Calculations
16055-Tiffany Park Sediment Pond #1
TJS
Sediment Pond #1
Peak flows per KCRTS analysis:
Q2yr = 1.9500 cfs
Q10yr = 4.3100 cfs
Q100yr = 8.2500 cfs
Required Surface Area at top of riser pipe:
SA = (2) * (Q2yr)= (2) * (1.95) = 4062.50 sf
(0.00096)(0.00096)
Basic Sediment Pond Geometry:
- SA at top of riser (at elevation shown in Civil Plans) =4,063 sf
- Minimum 3.5' deep pond requirement is met (top of riser to bottom)
- Maximum 3:1 interior side slope requirement is met
- Maximum 2:1 exterior side slope requirement is met
- 1' freeboard requirement is met (top of riser to crest of emergency spillway)
- Flat bottom requirement is met
- 1' deep spillway requirement is met
- Meets L:W ratio between 3:1 to 6:1
Principal Spillway - Riser Pipe
Qdesign = (Q10yr) * (1.6)= 6.90 cfs
h = 1 foot
Riser Inflow Curve - see the following page.
Emergency Overflow Spillway Length (with 3:1 side slopes):
Qdesign = (Q100yr) * (1.6)= 13.20 cfs
H = 0.2 inches, 0.2 inches minimum
L = (Q100yr) - (2.4) * (H) = (8.25) - (2.4) * (0.2)
(3.21) * (H3/2) (3.21) * (0.2
3/2)
L = 28.25 feet, 6' minimum length
L = 28.2545184 feet
-
Dewatering Orifice Diameter:
h = 3.5 foot riser
Ao = =
Ao = 0.037 sf
D = (13.54) * (Ao
0.5)
D = (13.54) * (0.0120.5)= 2.59 inches, 1 inch minimum
D = 2.588173564 inches
- The perforated tubing connected to the dewatering orifice must be at least 2"
larger in diameter than the orifice.
Ponds with berms less than 2' in height on grades < 5% can use a Type 2 MH with
a birdcage. Armour the emergency overflow spillway with riprap.
(SA) * (2h)0.5 (4,063) * (2*3.5)0.5
(0.6) * (3600) * (24) * (32.20.5) (0.6)*(3600)*(24)*(32.2
0.5)
Q100= 8.25 CFS
16055-Tiffany Park Sediment Pond #2
TJS
Sediment Pond #2
Peak flows per KCRTS analysis:
Q2yr = 0.9790 cfs Q10yr = 2.0300 cfs
Q100yr = 4.1300 cfs
Required Surface Area at top of riser pipe:
SA = (2) * (Q2yr)= (2) * (2.0567) = 2039.58 sf
(0.00096)(0.00096)
Sediment Pond Geometry:
- SA at top of riser (at elevation shown in Civil Plans) = 2,040 sf
- 3.5' deep pond (top of riser to bottom)
- 3:1 interior side slope
- Maximum 2:1 exterior side slope
- 1' freeboard (top of riser to crest of emergency spillway)
- Flat bottom
- 1' deep spillway
- Length at top of riser = 117' ; Width at top of riser = 39'
Principal Spillway - Riser Pipe
Qdesign = (Q10yr) * (1.6)= 3.25 cfs
h = 1 foot
Riser Inflow Curve - see the following page.
Emergency Overflow Spillway Length (with 3:1 side slopes):
Qdesign = (Q100yr) * (1.6)= 6.61 cfs
H = 0.2 inches, 0.2 inches minimum
L = (Q100yr) - (2.4) * (H) = (4.13) - (2.4) * (0.2)
(3.21) * (H3/2) (3.21) * (0.2
3/2)
L = 13.90 feet, 6' minimum length
L = 13.90467406 feet
-
Dewatering Orifice Diameter:
h = 3.5 foot riser
Ao = =
Ao = 0.018 sf
D = (13.54) * (Ao
0.5)
D = (13.54) * (0.0140.5)= 1.83 inches, 1 inch minimum
D = 1.833865318 inches
- The perforated tubing connected to the dewatering orifice must be at least 2"
larger in diameter than the orifice.
Ponds with berms less than 2' in height on grades < 5% can use a Type 2 MH with
a birdcage. Armour the emergency overflow spillway with riprap.
(SA) * (2h)0.5 (2,040) * (2)* 3.5)0.5
(0.6) * (3600) * (24) * (32.20.5) (0.6)*(3600)*(24)*(32.2
0.5)
Q100=4.13 CFS