Hill Residence SWPPPConstruction Stormwater General Permit (CSWGP)
Stormwater Pollution Prevention Plan
(SWPPP)
for
Hill Residence Drainage Design
Prepared for:
Department of Ecology
Northwest Regional Office
Permittee / Owner
Developer
Operator / Contractor
Danielle Hill
CG Engineering
TBD
8112 Talbot Rd., Edmonds, WA 98026
Certified Erosion and Sediment Control Lead (CESCL)
Name
Organization
Contact Phone Number
TBD
TBD
TBD
SWPPP Prepared By
Name
Organization
Contact Phone Number
Bennett Lanners
CG Engineering
425.778.8500
SWPPP Preparation Date
February 2021
Project Construction Dates
Activity / Phase
Start Date
End Date
Construction
TBD
TBD
Table of Contents
ProjectInformation (1.0)..............................................................................................................................5
ExistingConditions (1.1)...............................................................................................................................5
Proposed Construction Activities (1.2).....................................................................................................6
Construction Stormwater Best Management Practices(BMPs)...................................................................7
The13 Elements........................................................................................................................................7
Element 1: Preserve Vegetation / Mark Clearing Limits.......................................................................7
Element 2: Establish Construction Access............................................................................................8
Element 3: Control Flow Rates..............................................................................................................9
Element 4: Install Sediment Controls..................................................................................................10
Element5: Stabilize Soils....................................................................................................................11
Element6: Protect Slopes...................................................................................................................12
Element 7: Protect Drain Inlets...........................................................................................................13
Element 8: Stabilize Channels and Outlets.........................................................................................14
Element 9: Control Pollutants.............................................................................................................15
Element 10: Control Dewatering........................................................................................................17
Element11: Maintain BMPs...............................................................................................................18
Element12: Manage the Project........................................................................................................19
Element 13: Protect Low Impact Development (LID) BMPs...............................................................21
Pollution Prevention Team.........................................................................................................................22
Monitoring and Sampling Requirements....................................................................................................23
SiteInspection.........................................................................................................................................23
StormwaterQuality Sampling.................................................................................................................23
TurbiditySampling..............................................................................................................................23
pHSampling........................................................................................................................................25
Discharges to 303(d) or Total Maximum Daily Load (TMDL) Waterbodies................................................26
303(d) Listed Waterbodies......................................................................................................................26
TMDLWaterbodies.................................................................................................................................26
Reporting and Record Keeping...................................................................................................................
27
RecordKeeping.......................................................................................................................................27
SiteLog Book.......................................................................................................................................27
RecordsRetention...............................................................................................................................27
Updatingthe SWPPP...........................................................................................................................27
Reporting
Discharge Monitoring Reports
Notification of Noncompliance
List of Tables
1. Summary of Site Pollutant Consituents
2. Pollutants
3. pH -Modifying Sources
4. Dewatering BMPs
5. Management
6. BMP Implementation Schedule
7. Team Information
8. Turbidity Sampling Method
9. pH Sampling Method
List of Appendices
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
m
28
28
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
COz
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
GUILD
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
Project Information (1.0)
Project/Site Name: Hill Residence Drainage Design
Street/Location: 8112 Talbot Rd.
City: Edmonds State: WA Zip code: 98026
Subdivision: N/A
Receiving waterbody: Perrinville Creek
Existing Conditions (1.1)
Total acreage (including support activities such as off -site equipment staging yards, material
storage areas, borrow areas).
Total acreage: 0.770 ac
Disturbed acreage: 0.456 ac
Existing structures: 0.242 ac
Landscape topography: Generally sloping towards the existing house at an average of 1 %.
The south half of the parcel contains a steep downslope of about 40% towards the Perrinville
Creek.
Drainage patterns: The roof runoff is downspouted to splashblocks. Runoff from other
impervious areas is conveyed towards a yard drain and rock pad immediately east of the house
footprint, between the house and driveway.
Existing Vegetation: The developed portion of the site contains grass with some small
deciduous trees. The undeveloped portion of the site on the steep slope contains native
vegetation and three deciduous trees.
Critical Areas (wetlands, streams, high erosion risk, steep or difficult to stabilize slopes):
The Perrinville Creek is a Type F nonanadromous fishbearing stream with a 75' buffer.
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.
No known or suspected contaminants are associated with the site.
Table 1: — Summary of Site Pollutant Constituents
Constituent
(Pollutant)
Location
Depth
Concentration
Proposed Construction Activities (1.2)
Description of site development (example: subdivision):
This project includes the removal and replacement of the existing asphalt driveway with a new
concrete driveway, as well as the addition of gravel and concrete surfaces in backyard (west)
area, and the site frontage. The existing house will remain, and an infiltration trench will be
implemented to solve existing drainage issues.
Description of construction activities (example: site preparation, demolition, excavation):
Clearing of the construction area, excavating, filling and grading, utility installation, paving,
landscaping, and amendment of disturbed soils.
Description of site drainage including flow from and onto adjacent properties. Must be consistent
with Site Map in Appendix A:
Drainage from the site will flow into a proposed storm system consisting of catch basins and
conveyance pipes which will outfall to a rip -rap slope above Spada Lake. The existing
conveyance ditch at the south end of the site will be tied into the proposed conveyance system.
Drainage from the site impervious areas will be conveyed to an infiltration trench via catch
basins and conveyance pipes. The infiltration trench will outfall into the existing storm main on
Talbot avenue before reaching an eventual outfall in the Perrinville Creek.
Description of final stabilization (example: extent of revegetation, paving, landscaping):
All disturbed areas within the clearing limits will be landscaped with either grass or gravel.
Contaminated Site Information:
Proposed activities regarding contaminated soils or groundwater (example: on -site treatment
system, authorized sanitary sewer discharge):
N/A
Construction Stormwater Best Management Practices (BMPs)
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.
The 13 Elements
Element 1: Preserve Vegetation / 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 in the field.
In general, natural vegetation and native topsoil shall be retained in an undisturbed state to the
maximum extent possible.
A protective barrier shall be placed around the protected trees prior to land preparation or
construction activities and shall remain in place until all construction activity is terminated. No
equipment, chemicals, soil deposits or construction materials shall be placed within the
protective barriers. Any landscaping activities subsequent to the removal of the barriers shall be
accomplished with light machinery or hand labor.
List and describe BMPs:
• Preserving Natural Vegetation (BMP C101)
Installation Schedules: Install BMPs prior to clearing and grading.
Inspection and Maintenance plan: As needed.
Responsible Staff: CESCL.
Element 2: Establish Construction Access
Limit vehicle access to one route, if possible.
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, street cleaning, or wheel wash/tire baths may be necessary if the
stabilized construction access is not effective. If sediment is tracked off site, clean the affected
roadway thoroughly at the end of each day, or more necessary as needed. All wheel wash
wastewater shall be controlled on -site and CANNOT be discharged into waters of the State.
The existing asphalt driveway will serve as the construction entrance for the project. However, a
Stabilized Construction Entrance will be installed if required by the city inspector.
List and describe BMPs:
• Stabilized Construction Entrance/Exit (BMP C105)
Installation Schedules: Install BMPs prior to clearing and grading.
Inspection and Maintenance plan: As needed.
Responsible Staff: CESCL.
Element 3: Control Flow Rates
The project site has a gentle slope towards the existing house in the developed portion of the
site (<1 %). Flow rates around the site will be controlled by the silt fence that will be placed
around the downstream perimeter of the site.
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:
• Silt Fence (BMP C233)
Installation Schedules: Install BMPs prior to grading.
Inspection and Maintenance plan: As needed.
Responsible Staff: CESCL.
Element 4: Install Sediment Controls
Stormwater must be filtered prior to being discharged to an infiltration system or leaving the
construction site. Sediment control BMPs will be installed as one of the first steps of grading.
These BMPs must be functional before other land -disturbing activities, especially grading and
filling, take place.
A silt fence will be installed around the downstream perimeter of the site.
If sediment controls are ineffective and turbid water is observed discharging from the site,
additional energy dissipation BMPs and sediment control BMPs should be installed such as
wattles. It may also be necessary to stabilize soils per Element 5 that are not being worked on.
List and describe BMPs:
• Silt Fence (BMP C233)
• Wattles (BMP C235)
Installation Schedules: Install BMPs prior to clearing and grading.
Inspection and Maintenance plan: Repair sediment controls as needed. Remove sediment from
pond as needed.
Responsible Staff: CESCL.
Element 5: Stabilize Soils
Stabilize exposed and unworked soils by the BMPs listed below to prevent erosion. Protect
stockpiles with plastic covering or other approved sediment trapping measures. Stabilize
exposed soils with Temporary and Permanent Seeding, Mulching, Sodding,
Topsoil ing/Compost, or Surface Roughening. Minimize soil compaction by applying gravel base
early on areas to be paved.
The ESC Supervisor shall be familiar with BMPs for soil stabilization and dust control and
implement these BMPs where needed on the proposed site.
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: TBD End date: TBD
Will you construct during the wet season?
❑ Yes ❑ No
List and describe BMPs:
• Temporary and Permanent Seeding (BMP C120)
• Mulching (BMP C121)
• Nets and Blankets (BMP C122)
• Plastic Covering (BMP C123)
• Sodding (BMP C124)
• Topsoil ing/Composting (BMP C125)
• Surface Roughening (BMP C130)
• Dust Control (BMP C140)
Installation Schedules: As needed as soil is exposed.
Inspection and Maintenance plan: End of the shift before a holiday or weekend and prior to
forecasted rain events.
Responsible Staff: CESCL.
Element 6: Protect Slopes
All cut and fill slopes will be designed, constructed, and protected in a manner that minimizes
erosion.
Will steep slopes be present at the site during construction?
❑ Yes ❑ No
List and describe BMPs:
Temporary and Permanent Seeding (BMP C120)
Installation Schedules: Install BMPs prior to grading and as needed to minimize erosion.
Inspection and Maintenance plan: As needed.
Responsible Staff: CESCL.
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 will be implemented for all drainage inlets and culverts that could
potentially be impacted by sediment -laden runoff on and near the project site.
Inlet protection should be provided as shown on the C2.1 Plan. 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.
List and describe BMPs:
• Storm Drain Inlet Protection (BMP C220)
Installation Schedules: Before land disturbance for existing catch basins and as new catch
basins are made operable.
Inspection and Maintenance plan: Inlets will be inspected weekly at a minimum and daily during
storm events.
Responsible Staff: CESCL.
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 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.
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:
• Channel Lining (BMP C202)
• Outlet Protection (BMP C209)
Installation Schedules: Install BMPs prior to grading.
Inspection and Maintenance plan: As needed.
Responsible Staff: CESCL.
Element 9: Control Pollutants
The following pollutants are anticipated to be present on -site:
Table 2 — Pollutants
Pollutant (List pollutants and source, if applicable)
Concrete
Concrete process water
Concrete slurry
Utility Materials
List and describe BMPs:
• Concrete Handling (BMP C151)
• Sawcutting and Surfacing Pollution Prevention (BMP C152)
• Material Delivery, Storage and Containment (BMP C153)
Installation Schedules: As needed as pollutant source materials are used on -site.
Inspection and Maintenance plan: As needed.
Responsible Staff: CESCL.
Will maintenance, fueling, and/or repair of heavy equipment and vehicles occur on -site?
❑ Yes ❑ No
Will wheel wash or tire bath system BMPs be used during construction?
❑ Yes ® No
Will pH -modifying sources be present on -site?
❑ Yes ❑ No
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
❑
Rec cled concrete stockpiles
❑
Other (i.e., calcium lignosulfate) [please describe: ]
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.
Will uncontaminated water from water -only based shaft drilling for construction of building, road,
and bridge foundations be infiltrated provided the wastewater is managed in a way that prohibits
discharge to surface waters?
❑ Yes ❑ No
Element 10: Control Dewatering
Dewatering is not anticipated to be associated with this construction project.
If necessary, only clean, non -turbid dewatering water (such as well -point groundwater) may be
discharged to systems tributary to, or directly into, surface waters of the State, provided the
dewatering flow does not cause erosion or flooding of receiving waters.
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: N/A.
Installation Schedules: N/A.
Inspection and Maintenance plan: N/A.
Responsible Staff: CESCL.
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 11 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.
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)
Table 6 — BMP Implementation Schedule
Phase of Construction
Project
Stormwater BMPs
Date
Wet/Dry
Season
Pre -construction
Preserving Natural Vegetation
(BMP C101)
TBD
Dry
Pre -construction
Silt Fence (BMP C233)
TBD
Dry
Pre -construction
Storm Drain Inlet Protection
BMP C220
TBD
Land disturbance
Stabilized Construction
Entrance/Exit (BMP C105)
TBD
Dry
Land disturbance
Temporary and Permanent
Seeding (BMP C120)
TBD
Dry
Land disturbance
Mulching BMP C121
TBD
Dr
Land disturbance
Nets and Blankets BMP C122
TBD
Dr
Land disturbance
Plastic Covering (BMP C123)
TBD
Dry
Land disturbance
Sodding (BMP C124)
TBD
Dry
Land disturbance
Topsoiling/Composting (BMP
C125)
TBD
Dry
Land disturbance
Surface Roughening (BMP C130)
TBD
Dry
Land disturbance
Dust Control (BMP C140)
TBD
Dry
Land disturbance
Outlet protection (BMP C209)
TBD
Dry
Construction
Wattles (BMP C235)
TBD
Dry
Construction
Concrete handling (BMP C151)
TBD
Dry
Construction
Sawcutting and Surfacing
Pollution Prevention BMP C152
TBD
Dry
Construction
Material Delivery, Storage and
Containment BMP C153
TBD
Dry
Element 13: Protect Low Impact Development (LID) BMPs
No Low Impact Development BMPs are proposed for this project.
Pollution Prevention Team
Table 7 — Team Information
Title
Names
Phone Number
Certified Erosion and Sediment
Control Lead (CESCL)
TBD
TBD
Resident Engineer
CG Engineering
425.778.8500
Emergency Ecology Contact
TBD
TBD
Emergency Permittee/ Owner Contact
Danielle Hill
206.419.7543
Non -Emergency Owner Contact
Danielle Hill
206.419.7543
Monitoring Personnel
TBD
TBD
Ecology Regional Office
Northwest Regional Office
425.649.7000
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
File a blank form under Appendix D.
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.
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.
Stormwater Quality Sampling
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:
Review the SWPPP for compliance with Special Condition S9. Make appropriate
revisions within 7 days of the date the discharge exceeded the benchmark.
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 or submit an electronic report to the applicable Ecology Region's
Environmental Report Tracking System (ERTS) within 24 hours.
• Central Region (Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan,
Yakima): (509) 575-2490 or
http://www.ecy.wa.gov/programs/spills/forms/nerts online/CRO nerts online.html
• Eastern Region (Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant,
Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, Whitman): (509) 329-3400
or http://www.ecy.wa.gov/programs/spills/forms/nerts online/ERO nerts online.html
• Northwest Region (King, Kitsap, Island, San Juan, Skagit, Snohomish,
Whatcom): (425) 649-7000 or
http://www.ecV.wa.gov/programs/spills/forms/nerts online/NWRO nerts online.html
• Southwest Region (Clallam, Clark, Cowlitz, Grays Harbor, Jefferson, Lewis,
Mason, Pacific, Pierce, Skamania, Thurston, Wahkiakum,): (360) 407-6300 or
htto://www.ecv.wa.aov/oroarams/spills/forms/nerts online/SWRO nerts online.html
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.
0 1 - 5 NTU over background turbidity, if background is less than 50 NTU
0 1 % - 10% over background turbidity, if background is 50 NTU or greater
0 The discharge stops or is eliminated.
pH Sampling
pH monitoring is required for "Significant concrete work" (i.e., greater than 1000 cubic yards
poured concrete over the life of the project). The use of recycled concrete or 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 and recycled concrete, pH sampling begins when engineered soils or
recycled concrete 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
Discharges to 303(d) or Total Maximum Daily Load (TMDL)
Waterbodies
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): N/A
TMDL Waterbodies
Waste Load Allocation for CSWGP discharges: N/A
List and describe BMPs: N/A
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.
Reporting and Record Keeping
Record Keeping
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
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 S5.0 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.
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.
Reporting
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.
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 notified within 24-hours 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.
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
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.
Appendix/Glossary
A. Site Map
I I
Lea I I
I
I I
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I �
1 �
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F'e'�mvrue creek
1 I
PROJECT SITE I
V
Figure A-1. Site map.
B. BMP Detail
BMP details are shown on the approved TESC plan. Additional/alternative BMPs are
listed below and available for download from the Ecology Construction Stormwater
website:
http://www.ecy.wa.gov/programs/wq/stormwater/construction/index.htmI
Element #1 - Mark Clearing Limits
• BMP C101: Preserving Natural Vegetation
• BMP C102: Buffer Zones
• BMP C103: High Visibility Plastic or Metal Fence
• BMP C233: Silt Fence
Element #2 - Establish Construction Access
• BMP C105: Stabilized Construction Entrance/Exit
• BMP C106: Wheel Wash
• BMP C107: Construction Road/Parking Area Stabilization
Element #3 - Control Flow Rates
• BMP C203: Water Bars
• BMP C207: Check Dams
• BMP C209: Outlet Protection
• BMP C235: Wattles
• BMP C240: Sediment Trap
• BMP C241: Temporary Sediment Pond
Element #4 - Install Sediment Controls
• BMP C231: Brush Barrier
• BMP C232: Gravel Filter Berm
• BMP C233: Silt Fence
• BMP C234: Vegetated Strip
• BMP C235: Wattles
• BMP C240: Sediment Trap
• BMP C241: Temporary Sediment Pond
• BMP C250: Construction Stormwater Chemical Treatment
• BMP C251: Construction Stormwater Filtration
Element #5 - Stabilize Soils
• BMP C120: Temporary and Permanent Seeding
• BMP C121: Mulching
• BMP C122: Nets and Blankets
• BMP C123: Plastic Covering
• BMP C124: Sodding
• BMP C125: Topsoil ing/Composting
• BMP C126: Polyacrylamide for Soil Erosion Protection
• BMP C130: Surface Roughening
• BMP C131: Gradient Terraces
• BMP C140: Dust Control
Element #6 - Protect Slopes
• BMP C120: Temporary and Permanent Seeding
• BMP C121: Mulching
• BMP C122: Nets and Blankets
• BMP C123: Plastic Covering
• BMP C124: Sodding
• BMP C130: Surface Roughening
• BMP C131: Gradient Terraces
• BMP C200: Interceptor Dike and Swale
• BMP C201: Grass -Lined Channels
• BMP C203: Water Bars
• BMP C204: Pipe Slope Drains
• BMP C205: Subsurface Drains
• BMP C206: Level Spreader
• BMP C207: Check Dams
• BMP C208: Triangular Silt Dike (Geotextile- Encased
Check Dam)
Element #7 - Protect Drain Inlets
• BMP C220: Storm Drain Inlet Protection
Element #8 - Stabilize Channels and Outlets
• BMP C202: Channel Lining
• BMP C122: Nets and Blankets
• BMP C207: Check Dams
• BMP C209: Outlet Protection
Element #9 — Control Pollutants
• BMP C151: Concrete Handling
• BMP C152: Sawcutting and Surfacing Pollution Prevention
• BMP C153: Material Delivery, Storage and Containment
• BMP C154: Concrete Washout Area
• BMP C250: Construction Stormwater Chemical Treatment
• BMP C251: Construction Stormwater Filtration
• BMP C252: High pH Neutralization Using CO2
• BMP C253: pH Control for High pH Water
• See Volume IV — Source Control BMPs
Element #10 -Control Dewatering
• BMP C203: Water Bars
• BMP C236: Vegetative Filtration
Element #11: Maintain BMPs
• BMP C150: Materials On Hand
• BMP C160: Certified Erosion and Sediment Control Lead
Element #12: Manage the Project
• BMP C150: Materials On Hand
• BMP C160: Certified Erosion and Sediment Control Lead
• BMP C162: Scheduling
Element #13: Protect LID BMPs
• BMP C103: High Visibility Fence
C. Correspondence
D. Site Inspection Form
Permit # Inspection Time
Project Date
Name
Name of Certified Erosion Sediment Control Lead (CESCL) or qualified inspector if less than one acre
Print Name:
Approximate rainfall amount since the last inspection (in
inches):
Approximate rainfall amount in the last 24 hours (in
inches):
Current Weather Clear ❑ Cloudy Mist ❑ Rain ❑ Wind ❑ Fog ❑
A. Type of inspection: Weekly ❑ Post Storm Event Other ❑
B. Phase of Active Construction (check all that apply):
Pre Construction/installation of Clearing/Demo/Grading Infrastructure/storm/roads
erosion/sediment controls
Concrete pours Vertical Utilities
Construction/buildings
Offsite improvements Site temporary stabilized Final stabilization
C. Questions:
1. Were all areas of construction and discharge points inspected?
2. Did you observe the presence of suspended sediment, turbidity, discoloration,
or oil sheen
3. Was a water quality sample taken during inspection? (refer to permit
conditions 54 & 55)
4. Was there a turbid discharge 250 NTU or greater, or Transparency 6 cm or
less?*
5. If yes to #4 was it reported to Ecology?
Yes No
Yes No
Yes No
Yes No
Yes No
6. Is pH sampling required? pH range required is 6.5 to 8.5. Yes No
If answering yes to a discharge, describe the event. Include when, where, and why it happened; what
action was taken, and when.
*If answering yes to # 4 record NTU/Transparency with continual sampling daily until turbidity is 25 NTU or less/
transparency is 33 cm or greater.
Sampling
Results:
Date:
Parameter
Method (circle one)
Result
Other/Note
NTU
cm
pH
Turbidity
tube, meter,
laboratory
pH
Paper, kit, meter
D. Check the observed status of all items. Provide "Action Required "details and dates.
Element #
Inspection
BMPs
BMP
BMP
Action
Inspected
needs
failed
required
maintena
(describe
yes
no
n/a
nce
in
section
F)
1
Before beginning land disturbing
Clearing
activities are all clearing limits,
Limits
natural resource areas (streams,
wetlands, buffers, trees) protected
with barriers or similar BMPs?
(high visibility recommended)
2
Construction access is stabilized
Construction
with quarry spalls or equivalent
Access
BMP to prevent sediment from
being tracked onto roads?
Sediment tracked onto the road
way was cleaned thoroughly at the
end of the day or more frequent
as necessary.
3
Are flow control measures
Control Flow
installed to control stormwater
Rates
volumes and velocity during
construction and do they protect
downstream properties and
waterways from erosion?
If permanent infiltration ponds
are used for flow control during
construction, are they protected
from siltation?
4
All perimeter sediment controls
Sediment
(e.g. silt fence, wattles, compost
Controls
socks, berms, etc.) installed, and
maintained in accordance with the
Stormwater Pollution Prevention
Plan (SWPPP).
Sediment control BMPs (sediment
ponds, traps, filters etc.) have
been constructed and functional
as the first step of grading.
Stormwater runoff from disturbed
areas is directed to sediment
removal BMP.
5
Have exposed un-worked soils
Stabilize Soils
been stabilized with effective BMP
to prevent erosion and sediment
deposition?
Are stockpiles stabilized from erosion,
protected with sediment trapping
measures and located away from
drain inlet, waterways, and drainage
channels?
Have soils been stabilized at the end
of the shift, before a holiday or
weekend if needed based on the
weather forecast?
Has stormwater and ground water
6
been diverted away from slopes and
Protect Slopes
disturbed areas with interceptor
dikes, pipes and or swales?
Is off -site storm water managed
separately from stormwater
generated on the site?
Is excavated material placed on uphill
side of trenches consistent with safety
and space considerations?
Have check dams been placed at
regular intervals within constructed
channels that are cut down a slope?
7
Storm drain inlets made operable
Drain Inlets
during construction are protected.
Are existing storm drains within the
influence of the project protected?
8
Have all on -site conveyance channels
Stabilize
been designed, constructed and
Channel and
stabilized to prevent erosion from
Outlets
expected peak flows?
Is stabilization, including armoring
material, adequate to prevent erosion
of outlets, adjacent stream banks,
slopes and downstream conveyance
systems?
9
Are waste materials and demolition
Control
debris handled and disposed of to
Pollutants
prevent contamination of
stormwater?
Has cover been provided for all
chemicals, liquid products, petroleum
products, and other material?
Has secondary containment been
provided capable of containing 110%
of the volume?
Were contaminated surfaces cleaned
immediately after a spill incident?
Were BMPs used to prevent
contamination of stormwater by a pH
modifying sources?
Wheel wash wastewater is handled
and disposed of properly.
10
Concrete washout in designated
Control
areas. No washout or excess concrete
Dewatering
on the ground.
Dewatering has been done to an
approved source and in compliance
with the SWPPP.
Were there any clean non turbid
dewatering discharges?
11
Are all temporary and permanent
Maintain BMP
erosion and sediment control BMPs
maintained to perform as intended?
12
Has the project been phased to the
Manage the
maximum degree practicable?
Project
Has regular inspection, monitoring
and maintenance been performed as
required by the permit?
Has the SWPPP been updated,
implemented and records
maintained?
13
Is all Bioretention and Rain Garden
Protect LID
Facilities protected from
sedimentation with appropriate
BMPs?
Is the Bioretention and Rain Garden
protected against over compaction of
construction equipment and foot
traffic to retain its infiltration
capabilities?
Permeable pavements are clean and
free of sediment and sediment laden -
water runoff. Muddy construction
equipment has not been on the base
material or pavement.
Have soiled permeable pavements
been cleaned of sediments and pass
infiltration test as required by
stormwater manual methodology?
Heavy equipment has been kept off
existing soils under LID facilities to
retain infiltration rate.
E. Check all areas that have been inspected. ✓
All in place All disturbed All concrete wash out All material storage
BMPs soils n area areas
All discharge All equipment storage All construction
locations n areas entrances/exits
F. Elements checked "Action Required" (section D) describe corrective action to be taken. List the
element number; be specific on location and work needed. Document, initial, and date when the
corrective action has been completed and inspected.
Element
#
Description and Location
Action Required
Completion
Date
Initials
Attach additional page if needed
Sign the following certification:
"I certify that this report is true, accurate, and complete, to the best of my knowledge and belief"
Inspected by: (Signature) Date:
(print)
Title/Qualification of
Inspector:
E. Construction Stormwater General Permit (CSWGP)
F. 303(d) List Waterbodies / TMDL Waterbodies Information
G. Contaminated Site Information
H. Engineering Calculations