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Construction Stormwater General Permit (CSWGP)
Stormwater Pollution Prevention Plan
(SWPPP)
for
Mitchell Short Plat
Prepared for:
Department of Ecology
Northwest Regional Office
Permittee / Owner Developer Operator / Contractor
Teresa Mitchell
3625 Meadow Ave N
Renton, WA 98007
Steve Lippert
Trailside Homes
116 ½ S Washington St
Seattle, WA 98104
TBD
3625 Meadow Avenue North
Certified Erosion and Sediment Control Lead (CESCL)
Name Organization Contact Phone Number
TBD TBD TBD
SWPPP Prepared By
Name Organization Contact Phone Number
Lucas Zirotti Blueline 425-250-7223
SWPPP Preparation Date
March 22, 2021
Project Construction Dates
Activity / Phase Start Date End Date
General Construction Spring 2021 Spring 2022
DEVELOPMENT ENGINEERING
Nathan Janders 05/03/2021
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Table of Contents
1 Project Information ...............................................................................................................5
1.1 Existing Conditions .......................................................................................................5
1.2 Proposed Construction Activities ...................................................................................6
2 Construction Stormwater Best Management Practices (BMPs) ............................................7
2.1 The 13 Elements ...........................................................................................................7
2.1.1 Element 1: Preserve Vegetation / Mark Clearing Limits .........................................7
2.1.2 Element 2: Establish Construction Access .............................................................8
2.1.3 Element 3: Control Flow Rates...............................................................................9
2.1.4 Element 4: Install Sediment Controls ...................................................................10
2.1.5 Element 5: Stabilize Soils.....................................................................................11
2.1.6 Element 6: Protect Slopes....................................................................................12
2.1.7 Element 7: Protect Drain Inlets.............................................................................13
2.1.8 Element 8: Stabilize Channels and Outlets ..........................................................14
2.1.9 Element 9: Control Pollutants ...............................................................................15
2.1.10 Element 10: Control Dewatering ..........................................................................19
2.1.11 Element 11: Maintain BMPs .................................................................................20
2.1.12 Element 12: Manage the Project ..........................................................................21
2.1.13 Element 13: Protect Low Impact Development (LID) BMPs .................................22
3 Pollution Prevention Team .................................................................................................23
4 Monitoring and Sampling Requirements ............................................................................24
4.1 Site Inspection ............................................................................................................24
4.2 Stormwater Quality Sampling ......................................................................................24
4.2.1 Turbidity Sampling ...............................................................................................24
4.2.2 pH Sampling ........................................................................................................26
5 Discharges to 303(d) or Total Maximum Daily Load (TMDL) Waterbodies .........................27
5.1 303(d) Listed Waterbodies ..........................................................................................27
5.2 TMDL Waterbodies .....................................................................................................27
6 Reporting and Record Keeping ..........................................................................................28
6.1 Record Keeping ..........................................................................................................28
6.1.1 Site Log Book ......................................................................................................28
6.1.2 Records Retention ...............................................................................................28
6.1.3 Updating the SWPPP ...........................................................................................28
6.2 Reporting ....................................................................................................................29
6.2.1 Discharge Monitoring Reports ..............................................................................29
6.2.2 Notification of Noncompliance ..............................................................................29
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List of Tables
Table 1 – Summary of Site Pollutant Constituents ......................................................................5
Table 2 – Pollutants ..................................................................................................................15
Table 3 – pH-Modifying Sources ...............................................................................................17
Table 4 – Dewatering BMPs......................................................................................................19
Table 5 – Management .............................................................................................................21
Table 7 – Team Information ......................................................................................................23
Table 8 – Turbidity Sampling Method ........................................................................................24
Table 9 – pH Sampling Method .................................................................................................26
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
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1 Project Information
Project/Site Name:Mitchell Short Plat
Street/Location: 3625 Meadow Avenue North
City: Renton State: WA Zip code: 98007
Receiving waterbody:Lake Washington
1.1 Existing Conditions
Total acreage (including support activities such as off-site equipment staging yards, material
storage areas, borrow areas).
Total Acreage 0.92 AC (Parcel)
Disturbed Acreage: 0.52 AC
Existing Structures: Existing single-family residence, gravel/asphalt driveway, a detached
garage, miscellaneious hardscape. Only portions of the gravel/asphalt driveway are to be
removed in the final condition.
Topography: Majority of site slopes moderately to the northeast.
Drainage Patterns: Predominantly sheet flows to the northeast towards Meadow Ave N.
Existing Vegetation: The parcel consists of residential landscaping and lawn.
List of known impairments for 303(d) or Total Maximum Daily Load (TMDL) for the receiving
waterbody:
None noted at this time.
Critical Areas: None noted at this time.
Table 1 includes a list of suspected and/or known contaminants associated with the construction
activity. See Appendix G for contaminant location map and contaminant location.
None noted at this time.
Table 1 – Summary of Site Pollutant Constituents
Constituent
(Pollutant)
Location
(Remediation Area)Depth Concentration
(mg/kg)
N/A N/A N/A N/A
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1.2 Proposed Construction Activities
Description of site development (example: subdivision, single-famiy, cottages):
Subdivision.
Description of construction activities (example: site preparation, demolition, excavation):
This project proposes the subdivision of an existing parcel and constructing access and utilities
for the respective lots.
Construction activities will include site preparation, TESC installation, excavation for utilities,
foundations, grading, utility installation, asphalt paving, permeable pavement construction, and
landscaping.
Description of site drainage including flow from and onto adjacent properties. Must be consistent
with Site Map in Appendix A:
The site has no existing structures. In the existing condition, runoff from the site is generated
from one drainage basin sheet flows northeast down sloping terrain over onsite lawn towards
Meadow Ave N. In the developed condition, impervious site area will utilize infiltration to contorl
runoff. An overflow will be provided for infiltration facilities, where the outfall to the overflow will
closely match the site existing discharge location towards Meadows Ave N.
Description of final stabilization (example: extent of revegetation, paving, landscaping):
In final conditions the developed site will be fully stabilized with paving of access, and seeding
of exposed dirt disturbed during construction within clearling limits. Permanent storm drainage
infrastructure will collect and treat majority of onsite surface runoff through infiltration devices to
closely match the site existing discharge location.
Contaminated Site Information:
Proposed activities regarding contaminated soils or groundwater (example: on-site treatment
system, authorized sanitary sewer discharge):
None noted at this time.
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2 Construction Stormwater Best Management Practices (BMPs)
Alternate City approved BMPs shall be utilized in the event the BMP(s) listed below are deemed
ineffective or inappropriate during construction to satisfy the requirements set forth in the
General NEDES Permit (Appendix E). 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 alternative 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. Please refer to the TESC plan
included in Appendix A and BMP details included in Appendix B.
2.1 The 13 Elements
2.1.1 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. The BMPs relevant
to marking the clearing limits that will be applied for this project include:
Applicable BMPs:
· City of Renton Standard Plan - 212.00: Stake and Wire Fence
· City of Renton Standard Plan – 214.00: Silt Fence
Installation Schedules: Start of project and replaced as needed and at start of wet season.
Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspection to
identify deficiencies in onsite BMPs and anticipate potential problems and remedies.
Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this
SWPPP.
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2.1.2 Element 2: Establish Construction Access
Construction access or activities occurring on unpaved areas shall be minimized, where
necessary, access points shall be stabilized to minimize the tracking of sediment onto public
roads. Construction vehicle access and exit shall be limited to one route, if possible. Wheel
washing, street sweeping, and street cleaning may be necessary if the stabilized construction
access is not effective. All wash wastewater shall be controlled on site and cannot be
discharged into waters of the State. If sediment is tracked off site, roads shall be cleaned
thoroughly at the end of each day, or more frequently during wet weather. Sediment shall be
removed from roads by shoveling or pickup sweeping and shall be transported to a controlled
sediment disposal area.
Applicable BMPs:
· City of Renton Standard Plan – 215.10: Stabilized Construction Entrance
Installation Schedules: Start of project and replaced as needed and at start of wet season.
Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspection to
identify deficiencies in onsite BMPs and anticipate potential problems and remedies.
Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this
SWPPP.
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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. In general, 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)
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
Silt fence will act as a barrier between the runoff generated onsite and properties and
waterways downstream of the project site. Due to the small area of disturbace, silt fencing
should be sufficient for controlling flow rates on the site.
List and describe BMPs: City of Renton Standard Plan – 214.00: Silt Fence
Installation Schedules: Start of project and as required.
Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections
to identify deficiencies in on-site BMPs and anticipate potential problems and remedies. More
frequent inspections during periods of heavy rain.
Responsible Staff: identified Certified Erosion and Sediment Control Lead in Section 3 of the
SWPPP.
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2.1.4 Element 4: Install Sediment Controls
All stormwater runoff from disturbed areas shall pass through appropriate sediment removal
BMPs before leaving the construction site. BMPs will be constructed as one of the first steps of
grading and will be functional before other land disturbing activities take place.
Additionally, sediment will be removed from paved areas in and adjacent to construction work
areas manually or using mechanical sweepers to minimize tracking of sediments on vehicle tires
away from the site and to minimize wash off sediments from adjacent streets in runoff.
List and describe BMPs:
· City of Renton Standard Plan – 214.00: Silt Fence
Installation Schedules: Start of project and as required.
Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections
to identify deficiencies in on-site BMPs and anticipate potential problems and remedies. More
frequent inspections during periods of heavy rain.
Responsible Staff: identified Certified Erosion and Sediment Control Lead in Section 3 of the
SWPPP.
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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.
In general, cut and fill slopes will be stabilized as soon as possible and soil stockpiles will be
temporarily covered with plastic sheeting. All stockpiled soils shall be stabilized from erosion,
protected with sediment trapping measures, and where possible, be located away from storm
drain inlets, waterways, and drainage channels.
Earthwork quantities: To be determined.
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: Spring 2021 End date: Spring 2022
Will you construct during the wet season?
Yes No
Applicable BMPs:
Element 5: Stabilize Soils:
· Section C.3.2 of the 2017 COR SWDM: Mulching
· Section C.3.3 of the 2017 COR SWDM: Nets and Blankets
· Section C.3.4 of the 2017 COR SWDM: Plastic Covering
· Section C.3.10 of the 2017 COR SWDM: Seeding
· Section D.2.1.8 of the 2017 COR SWDM: Dust Control
· Early application of gravel base on areas to be paved
Installation Schedules: Start of project and replaced as needed and at start of wet season.
Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections
to identify deficiencies in onsite BMPs and anticipate potential problems and remedies.
Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this
SWPPP.
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2.1.6 Element 6: Protect Slopes
Will steep slopes be present at the site during construction?
Yes No
Cut and fill slopes within the site will be designed, constructed, and protected in a manner that
minimizes erosion. The BMPs to be used to protect slopes for this project are listed below.
Applicable BMPs:
· Section C.3.2 of the 2017 COR SWDM: Mulching
· Section C.3.3 of the 2017 COR SWDM: Nets and Blankets
· Section C.3.10 of the 2017 COR SWDM: Seeding
Installation Schedules: Start of project and replaced as needed and at start of wet season.
Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections
to identify deficiencies in onsite BMPs and anticipate potential problems and remedies.
Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this
SWPPP.
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2.1.7 Element 7: Protect Drain Inlets
All storm drain inlets and culverts operable during construction shall be protected to prevent
unfiltered or untreated water from entering the drainage conveyance system. The priority,
however, shall be to keep all access roads clean of sediment and keep street wash water from
entering storm drains until treatment can be provided. Inlet protection shall be implemented for
all drainage inlets and culverts that could potentially be impacted by sediment-laden runoff on
and near the project site. The following inlet protection measures will be applied on this project:
Applicable BMPs:
· City of Renton Standard Plan – 216.30: Catch Basin Insert
Installation Schedules: Start of project and replaced as needed and at start of wet season.
Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections
to identify deficiencies in onsite BMPs and anticipate potential problems and remedies.
Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this
SWPPP.
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2.1.8 Element 8: Stabilize Channels and Outlets
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.
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.
Applicable BMPs:
N/A
Installation Schedules: Start of project and replaced as needed and at start of wet season.
Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections
to identify deficiencies in onsite BMPs and anticipate potential problems and remedies.
Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this
SWPPP.
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2.1.9 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
Diesel Fuel
Asphalt
Building, insulation, and roofing materials
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. BMPs to be implemented to control specific sources of
pollutants are discussed below.
Chemical storage:
§ Any chemicals stored in the construction areas will conform to the appropriate
source control BMPs listed in the COR SWDM. All chemicals shall have cover,
containment, and protection provided on site, per Section D.2.2.4 of the 2017
COR SWDM for Material Delivery, Storage and Containment.
§ 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.
Excavation and tunneling spoils dewatering waste:
§ Dewatering BMPs and BMPs specific to the excavation and tunneling (including
handling of contaminated soils) are discussed under Element 10.
Demolition:
§ Dust released from demolished sidewalks, buildings, or structures will be
controlled using Dust Control measures (Section D.2.1.8 of the 2017 COR
SWDM).
§ Storm drain inlets vulnerable to stormwater discharge carrying dust, soil, or
debris will be protected using Storm Drain Inlet Protection (City of Renton
Standard Plan – 216.30: Catch Basin Insert, as described above for Element 7).
§ Process water and slurry resulting from sawcutting and surfacing operations will
be prevented from entering the waters of the State by implementing Sawcutting
Page |16
and Surfacing Pollution Prevention measures (Section D.2.2.3 of the 2017 COR
SWDM).
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
(Section D.2.2.1 of the 2017 COR SWDM). Concrete wash out areas shall not be
allowed on bare dirt or allowed to drain to bare dirt or the storm system.
Sanitary wastewater:
§ Portable sanitation facilities will be firmly secured, regularly maintained, and
emptied when necessary.
Solid Waste:
§ Solid waste will be stored in secure, clearly marked containers.
Other:
§ Other BMPs will be administered as necessary to address any additional
pollutant sources on site.
Installation Schedules: Start of project and replaced as needed and as start of wet season.
Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections
to identify deficiencies in onsite BMPs and anticipate potential problems and remedies.
Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this
SWPPP.
Will maintenance, fueling, and/or repair of heavy equipment and vehicles occur on-site?
Yes No
Vehicles, construction equipment, and/or petroleum product storage/dispensing:
§ All vehicles, equipment, and petroleum product storage/dispensing area swill be
inspected regularly to detect any leaks or spills, and to identify maintenance
needs to prevent leaks or spills.
§ On-site fueling tanks and petroleum product storage containers shall include
secondary containment.
§ Spill prevention measures, such as drip pans, will be used when conducting
maintenance and repair of vehicles or equipment.
§ In order to perform emergency repairs on site, temporary plastic will be placed
beneath and, if raining, over the vehicle.
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§ Contaminated surfaces shall be cleaned immediately following any discharge or
spill incident.
Applicable BMPs:
· Material Delivery, Storage and Containment (Section D.2.2.4 of the 2017 COR SWDM)
Fuel onsite will be comprised of fuel tanks in operating equipment ranging between 50-100
gallons of off road diesel fuel. The BMPs listed below as well as procedures described above
should be followed with refueling equipment. Spill kits should be kept on hand and accessible
during refueling activities.
Installation Schedules: Start of project and replaced as needed and at start of wet season.
Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections
to identify deficiencies in onsite BMPs and anticipate potential problems and remedies.
Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this
SWPPP.
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
Recycled concrete stockpiles
Other (i.e., calcium lignosulfate) [please describe:]
Applicable BMPs:
§Monitoring should be performed to ensure concrete placement does not
result in excessively high pH in stormwater runoff. pH testing should be
performed on a weekly basis, from the start of concrete work until pH
drops below 8.5 su.
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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 (Section D.2.2.1 of the 2017 COR SWDM).
Concrete wash out areas shall not be allowed on bare dirt or allowed to
drain to bare dirt or the storm system.
Installation Schedules: Start of project and replaced as needed and at start of wet season.
Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections
to identify deficiencies in onsite BMPs and anticipate potential problems and remedies.
Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this
SWPPP.
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.
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
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2.1.10 Element 10: Control Dewatering
All dewatering water from open cut excavation, tunneling, foundation work, trench, or
underground vaults shall be discharged into a controlled conveyance system prior to discharge
to a sediment trap or sediment pond. Channels will be stabilized, per Element #8.
Clean, non-turbid dewatering water will not be routed through stormwater sediment ponds, and
will not be discharged to systems tributary to the receiving waters of the State in a manner that
does no cause erosion, flooding, or a violation of State water quality standards in the receiving
water.
Highly turbid dewatering water from soils known or suspected to be contaminated, or from use
of construction equipment, will require additional monitoring and treatment as required for the
specific pollutants based on the receiving waters into which the discharge is occurring. Such
monitoring is the responsibility of the contractor.
Dewatering of soils known to be free of contamination will trigger BMPs to trap sediment and
reduce turbidity. Other BMPs to be used for sediment trapping and turbidity reduction include
the following.
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)
Installation Schedules: Start of project and replaced as needed and as start of wet season.
Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections
to identify deficiencies in onsite BMPs and anticipate potential problems and remedies.
Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this
SWPPP.
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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 2017 City of Renton Surface Water Design Manual, Appendix D).
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 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)
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2.1.13 Element 13: Protect Low Impact Development (LID) BMPs
During construction, inlet protection for catch basins shall be installed and maintained in
accordance with City of Renton Standard Plan – 216.30: Catch Basin Insert. Pipes should be
protected during installation using temporary plug to prevent excess groundwater from entering
the trench. Clean gravel shall be installed into the dispersion trench and protected until the
surrounding ground is stabilized with seeding or mulch. Native vegetated flowpaths downstream
of the dispersion trenches should be clearly delineated and protected from disturbance.
The majority of the site area will have native vegetation or landscaping coverage. These areas
shall be protected from heavy construction equipment to the maximum extent feasible in order
to prevent compaction of the underlying soils.
Page |23
3 Pollution Prevention Team
Table 7 – Team Information
Title Name(s)Phone Number
Certified Erosion and
Sediment Control Lead
(CESCL)
TBD TBD
Resident Engineer Yannick Mets, PE 425-250-7262
Emergency Ecology
Contact
Tracie Walters 425-649-4484
Emergency Permittee/
Owner Contact
Steve Lippert 206-706-1527
Non-Emergency Owner
Contact
Steve Lippert 206-706-1527
Monitoring Personnel TBD TBD
Ecology Regional Office Northwest Region (425) 649-7000
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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
See form in 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.
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 |25
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.ecy.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
http://www.ecy.wa.gov/programs/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.
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 |26
4.2.2 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
To be determined
Page |27
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): None noted at this time.
5.2 TMDL Waterbodies
Waste Load Allocation for CWSGP 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.
Page |28
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 |29
6.2 Reporting
6.2.1 Discharge Monitoring Reports
Cumulative soil disturbance is less than (1) acre; therefore, Discharge Monitoring Reports
(DMRs) are not required.
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 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.
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
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
Page |30
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 |31
Appendix/Glossary
A. Site Map
INSERT TP-01
and TD-01
Page |32
B. BMP Detail
1.CONDITIONS OF USE
1.1.TO ESTABLISH CLEARING LIMITS, STAKE AND WIRE FENCE MAY BE USED:
1.1.1.AT THE BOUNDARY OF CRITICAL AREAS, THEIR BUFFERS AND OTHER AREAS REQUIRED TO BE LEFT UNCLEARED.
1.1.2.AS NECESSARY TO CONTROL VEHICLE ACCESS TO AND ON THE SITE.
2.MAINTENANCE AND REQUIREMENTS
2.1.IF THE FENCE IS DAMAGED OR VISIBILITY REDUCED, IT SHALL BE REPAIRED OR REPLACED IMMEDIATELY AND VISIBILITY RESTORED.
2.2.DISTURBANCE OF A CRITICAL AREA, CRITICAL BUFFER AREA, NATIVE GROWTH RETENTION AREA, OR OTHER AREA REQUIRED TO BE
LEFT UNDISTURBED SHALL BE REPORTED TO THE CITY OF RENTON FOR RESOLUTION.
2.3.THE CITY MAY REQUIRE MORE SUBSTANTIAL FENCING IF THE FENCE DOES NOT PREVENT ENCROACHMENT INTO THOSE AREAS THAT
ARE NOT TO BE DISTURBED.
NOTES
SURVEYFLAGGINGBAILINGWIRE
DO NOT NAIL OR STAPLE WIRE
TO TREES
METAL FENCE POST (TYP.)3' MIN.
10' - 20'
12" MIN.
STAKE AND WIRE FENCE
STD. PLAN - 212.00
PUBLIC WORKS
DEPARTMENT
APPROVED:
DATEGreggZimmerman
Public Works Administrator
UNLESS OTHERWISE NOTED, DRAWING IS NOT TO SCALE (NTS)
DocuSign Envelope ID: 6EECF5B6-602A-4E4A-B436-A317AA638878
9/28/2018 | 9:45 AM PDT
1.CONDITIONS OF USE
1.1.SILT FENCE MAY BE USED DOWNSLOPE OF ALL DISTURBED AREAS.
1.2.SILT FENCE IS NOT INTENDED TO TREAT CONCENTRATED FLOWS, NOR IS IT INTENDED TO TREAT SUBSTANTIAL AMOUNTS OF OVERLAND FLOW. ANY CONCENTRATED
FLOW MUST BE CONVEYED THROUGH THE DRAINAGE SYSTEM TO A SEDIMENT TRAP OR POND.
2.DESIGN AND INSTALLATION SPECIFICATIONS
2.1.THE GEOTEXTILE USED MUST MEET THE STANDARD LISTED BELLOW. A COPY OF THE MANUFACTURER'S FABRIC SPECIFICATIONS MUST BE AVAILABLE ON SITE.
2.2.STANDARD STRENGTH FABRIC REQUIRES WIRE BACKING TO INCREASE THE STRENGTH OF THE FENCE. WIRE BACKING OR CLOSER POST SPACING MAY BE REQUIRED
FOR EXTRA STRENGTH FABRIC IF FIELD PERFORMANCE WARRANTS A STRONGER FENCE.
2.3.WHERE THE FENCE IS INSTALLED, THE SLOPE SHALL NOT BE STEEPER THAN 2H:1V
2.4.IF A TYPICAL SILT FENCE IS USED, THE STANDARD 4"X4" TRENCH MAY BE REDUCED AS LONG AS THE BOTTOM 8 INCHES OF THE SILT FENCE FABRIC IS WELL BURIED AND
SECURE IN A TRENCH THAT STABILIZES THE FENCE AND DOES NOT ALLOW WATER TO BYPASS OR UNDERMINE THE SILT FENCE.
2.5.FILTER FABRIC FENCES SHALL BE INSTALLED ALONG CONTOURS WHENEVER POSSIBLE.
3.MAINTENANCE STANDARDS
3.1.ANY DAMAGE SHALL BE REPAIRED IMMEDIATELY.
3.2.IF CONCENTRATED FLOWS ARE EVIDENT UPHILL OF THE FENCE, THEY MUST BE INTERCEPTED AND CONVEYED TO A SEDIMENT TRAP OR POND.
3.3.IT IS IMPORTANT TO CHECK THE UPHILL SIDE OF THE FENCE FOR SIGNS OF THE FENCE CLOGGING AND ACTING AS A BARRIER TO FLOW AND THEN CAUSING
CHANNELIZATION OF FLOWS PARALLEL TO THE FENCE. IF THIS OCCURS, REPLACE THE FENCE OR REMOVE THE TRAPPED SEDIMENT.
3.4.SEDIMENT MUST BE REMOVED WHEN SEDIMENT IS 6 INCHES HIGH.
3.5.IF THE FILTER FABRIC (GEOTEXTILE) HAS DETERIORATED DUE TO ULTRAVIOLET BREAKDOWN, IT SHALL BE REPLACED.
NOTES:
JOINTS IN FILTER FABRIC SHALL BE SPLICED AT
POSTS. USE STAPLES, WIRE RINGS, OR
EQUIVALENT TO ATTACH FABRIC TO POSTS
2"x2" 14 GAUGE WIRE, OR
EQUIVALENT, IF STANDARD
STRENGTH FABRIC USED
FILTER FABRIC
2' MIN.
12" MIN.
4"x4" MIN. TRENCH
BACKFILL TRENCH WITH NATIVE SOIL
OR 3/4" TO 1-1/2" WASHED GRAVEL
2"x4" WOOD POSTS, STEEL FENCE POSTS, OR EQUIVALENT (TYP.)
6' MAX.
POST SPACING MAY BE INCREASED
TO 8' IF WIRE BACKING IS USED
AOS (ASTM D4751)30-100 SIEVE SIZE (0.60-0.15mm) FOR SILT FILM
50-100 SIEVE SIZE (0.30-0.15mm) FOR OTHER FABRICS
WATER PERMITTIVITY (ASTM D4491)0.02 SEC-1MINIMUM
GRAB TENSILE STRENGTH (ASTM D4632)180 LBS. MIN. FOR EXTRA STRENGTH FABRIC
100 LBS. MIN. FOR STANDARD STRENGTH FABRIC
GRAB TENSILE ELONGATION (ASTM D4632)30% MAX. (WOVEN)
ULTRAVIOLET RESISTANCE (ASTM D4355)70% MIN.
SILT FENCE
STD. PLAN - 214.00
PUBLIC WORKS
DEPARTMENT
APPROVED:
DATEGreggZimmerman
Public Works Administrator
UNLESS OTHERWISE NOTED, DRAWING IS NOT TO SCALE (NTS)
DocuSign Envelope ID: 6EECF5B6-602A-4E4A-B436-A317AA638878
9/28/2018 | 9:45 AM PDT
EXIST ING R OA D
1.CONDITION OF USE
1.1.CONSTRUCTION ENTRANCE SHALL BE STABILIZED WHEREVER TRAFFIC WILL BE LEAVING A CONSTRUCTION SITE AND TRAVELING ON PAVED ROADS OR OTHER
PAVED AREAS WITHIN 1,000 FEET OF THE SITE.
1.2.FOR RESIDENTIAL CONSTRUCTION PROVIDE STABILIZED CONSTRUCTION ENTRANCES FOR EACH RESIDENCE IN ADDITION TO THE MAIN SUBDIVISION
ENTRANCE. STABILIZED SURFACES SHALL BE OF SUFFICIENT LENGTH/WIDTH TO PROVIDE VEHICLE ACCESS/PARKING, BASED ON LOT SIZE/CONFIGURATION.
2.DESIGN AND INSTALLATION SPECIFICATIONS
2.1.A SEPARATION GEOTEXTILE SHALL BE PLACED UNDER THE SPALLS TO PREVENT FINE SEDIMENT FROM PUMPING UP INTO THE ROCK PAD. THE GEOTEXTILE
SHALL MEET THE FOLLOWING STANDARDS:
2.2.DO NOT USE CRUSHED CONCRETE, CEMENT, OR CALCIUM CHLORIDE FOR CONSTRUCTION ENTRANCE STABILIZATION BECAUSE THESE PRODUCTS RAISE pH
LEVELS IN STORMWATER AND CONCRETE DISCHARGE TO SURFACE WATERS OF THE STATE IS PROHIBITED.
2.3.HOG FUEL (WOOD BASED MULCH) MAY BE SUBSTITUTED FOR OR COMBINED WITH QUARRY SPALLS IN AREAS THAT WILL NOT BE USED FOR PERMANENT ROADS.
HOG FUEL IS NOT RECOMMENDED FOR ENTRANCE STABILIZATION IN URBAN AREAS. THE INSPECTOR MAY AT ANY TIME REQUIRE THE USE OF QUARRY SPALLS
IF THE HOG FUEL IS NOT PREVENTING SEDIMENT FROM BEING TRACKED ONTO PAVEMENT OR IF THE HOG FUEL IS BEING CARRIED ONTO PAVEMENT.
2.4.FENCING SHALL BE INSTALLED AS NECESSARY TO RESTRICT TRAFFIC TO THE CONSTRUCTION ENTRANCE.
2.5.WHENEVER POSSIBLE, THE ENTRANCE SHALL BE CONSTRUCTED ON A FIRM, COMPACTED SUBGRADE. THIS CAN SUBSTANTIALLY INCREASE THE
EFFECTIVENESS OF THE PAD AND REDUCE THE NEED FOR MAINTENANCE.
3.MAINTENANCE STANDARDS
3.1.QUARRY SPALLS SHALL BE ADDED IF THE PAD IS NO LONGER IN ACCORDANCE WITH THE SPECIFICATIONS.
3.2.IF THE ENTRANCE IS NOT PREVENTING SEDIMENT FROM BEING TRACKED ONTO PAVEMENT, THEN ALTERNATIVE MEASURES TO KEEP THE STREETS FREE OF
SEDIMENT SHALL BE USED. THIS MAY INCLUDE STREET SWEEPING, AN INCREASE IN THE DIMENSIONS OF THE ENTRANCE, OR THE INSTALLATION OF A WHEEL
WASH. IF WASHING IS USED, IT SHALL BE DONE ON AN AREA COVERED WITH CRUSHED ROCK, AND WASH WATER SHALL DRAIN TO A SEDIMENT TRAP OR POND.
3.3.ANY SEDIMENT THAT IS TRACKED ONTO PAVEMENT SHALL BE REMOVED IMMEDIATELY BY SWEEPING. THE SEDIMENT COLLECTED BY SWEEPING SHALL BE
REMOVED OR STABILIZED ON SITE. THE PAVEMENT SHALL NOT BE CLEANED BY WASHING DOWN THE STREET, EXCEPT WHEN SWEEPING IS INEFFECTIVE AND
THERE IS A THREAT TO PUBLIC SAFETY. IF IT IS NECESSARY TO WASH THE STREETS, A SMALL SUMP MUST BE CONSTRUCTED. THE SEDIMENT WOULD THEN BE
WASHED INTO THE SUMP WHERE IT CAN BE CONTROLLED AND DISCHARGED APPROPRIATELY. WASH WATER MUST BE PUMPED BACK ONTO THE SITE AND
CANNOT DISCHARGE TO SYSTEMS TRIBUTARY TO SURFACE WATERS.
3.4.ANY QUARRY SPALLS THAT ARE LOOSENED FROM THE PAD AND END UP ON THE ROADWAY SHALL BE REMOVED IMMEDIATELY.
3.5.IF VEHICLES ARE ENTERING OR EXITING THE SITES AT POINTS OTHER THAN THE CONSTRUCTION ENTRANCE(S), FENCING SHALL BE INSTALLED TO CONTROL
TRAFFIC.
NOTES:
CONSTRUCTION ENTRANCE NOTES:
1.DRIVEWAYS SHALL BE PAVED TO
THE EDGE OF THE RIGHT-OF-WAY
PRIOR TO INSTALLATION OF THE
CONSTRUCTION ENTRANCE TO
AVOID DAMAGING OF THE
ROADWAY.
2.IT IS RECOMMENDED THAT THE
ENTRANCE BE CROWNED SO THAT
RUNOFF DRAINS OFF THE PAD
INSTALL DRIVEWAY CULVERT
IF THERE IS A ROADSIDE
DITCH PRESENT, AS PER CITY
ROAD STANDARDS
GEOTEXTILE
4"-8" QUARRY SPALLS
12" MIN. THICKNESS
15' MIN.
PROVIDE FULL WIDTH OF
INGRESS/EGRESS AREA
100' MIN.
GRAB TENSILE STRENGTH (ASTM D4632)200 LBS. MIN.
GRAB TENSILE ELONGATION (ASTM D4632)30% MAX. (WOVEN)
CBR PUNCTURE STRENGTH (ASTM D6241)495 LBS. MIN.
AOS (ASTM D4751)20-45 (U.S. STANDARD SIEVE SIZE)
R = 25' MIN.
STABILIZED CONSTRUCTION ENTRANCE
STD. PLAN - 215.10
PUBLIC WORKS
DEPARTMENT
APPROVED:
DATEGreggZimmerman
Public Works Administrator
UNLESS OTHERWISE NOTED, DRAWING IS NOT TO SCALE (NTS)
DocuSign Envelope ID: 6EECF5B6-602A-4E4A-B436-A317AA638878
9/28/2018 | 9:45 AM PDT
NOTES:
SECTION VIEW
ISOMETRIC VIEW
DRAINAGE GRATE TRIM
GRATE FRAME
FILTERED
WATER
SEDIMENT AND DEBRIS
OVERFLOW BYPASS
BELOW INLET GRATE DEVICE
DRAINAGE GRATE
RECTANGULAR GRATE SHOWN)RETRIEVAL SYSTEM (TYP.)
OVERFLOW BYPASS (TYP.)
BELOW INLET GRATE DEVICE
1.PROTECTION SHALL BE PROVIDED FOR ALL STORM DRAIN INLETS DOWNSLOPE AND WITHIN 500 FEET OF A DISTURBED OR
CONSTRUCTION AREA, UNLESS THE RUNOFF THAT ENTERS THE CATCH BASIN WILL BE CONVEYED TO A SEDIMENT POND OR TRAP.
2.INLET PROTECTION SHALL BE USED TO PROTECT THE DRAINAGE SYSTEM.
3.THE CONTRIBUTING DRAINAGE AREA MUST NOT BE LARGER THAN ONE ACRE.
4.SIZE THE BELOW INLET GRATE DEVICE (BIGD) FOR THE STORMWATER STRUCTURE IT WILL SERVICE.
5.THE BIGD SHALL HAVE A BUILT-IN HIGH-FLOW RELIEF SYSTEM (OVERFLOW BYPASS).
6.THE RETRIEVAL SYSTEM MUST ALLOW REMOVAL OF THE BIGD WITHOUT SPILLING THE COLLECTED MATERIAL.
7.PERFORM MAINTENANCE IN ACCORDANCE WITH STANDARD SPECIFICATION 8-01.3(15).
8.ANY SEDIMENT IN THE CATCH BASIN INSERT SHALL BE REMOVED WHEN THE SEDIMENT HAS FILLED ONE-THIRD OF THE AVAILABLE
STORAGE. THE FILTER MEDIA FOR THE INSERT SHALL BE CLEANED OR REPLACED AT LEAST MONTHLY.
5" MAX.
CATCH BASIN INSERT
STD. PLAN - 216.30
PUBLIC WORKS
DEPARTMENT
APPROVED:
DATEGreggZimmerman
Public Works Administrator
UNLESS OTHERWISE NOTED, DRAWING IS NOT TO SCALE (NTS)
DocuSign Envelope ID: 6EECF5B6-602A-4E4A-B436-A317AA638878
9/28/2018 | 9:45 AM PDT
SECTION C.3 CONSTRUCTION STORMWATER POLLUTION PREVENTION (CSWPP) MEASURES
12/12/2016 2017 City of Renton Surface Water Design Manual C-112
FIGURE C.3.1.A SCHEMATIC REPRESENTATION OF A STABILIZED CONSTRUCTION ENTRANCE
C.3.2 MULCHING
Purpose
The purpose of mulching soils is to provide immediate temporary protection from erosion. Mulch also
enhances plant establishment by conserving moisture, holding fertilizer, seed, and topsoil in place, and
moderating soil temperatures. There is an enormous variety of mulches that may be used. Only the most
common types are discussed in this section.
Conditions of Use
As a temporary cover measure, mulch should be used:
1. On disturbed areas that require cover measures for less than 30 days
2. As a cover for seed during the wet season and during the hot summer months
3. During the wet season on slopes steeper than 3H:1V with more than 10 feet of vertical relief.
Design and Installation Specifications
For mulch materials, application rates, and specifications, see Table C.3.2.A.
Note: Thicknesses may be increased for disturbed areas in or near critical areas or other areas highly
susceptible to erosion.
•PER KING COUNTY ROAD DESIGN AND CONSTRUCTION STANDARDS (KCRDCS), DRIVEWAYS SHALL
BE PAVED TO EDGE OF R-O-W PRIOR TO INSTALLATION OF THE CONSTRUCTION ENTRANCE TO
AVOID DAMAGING OF THE ROADWAY.
•IT IS RECOMMENDED THAT THE ENTRANCE BE CROWNED SO THAT RUNOFF DRAINS OFF THE PAD.
12" MIN.THICKNESS
PROVIDE FULL WIDTH OFINGRESS/EGRESS AREA
IF A ROADSIDE DITCH IS
PRESENT, INSTALLDRIVEWAY CULVERT
PER KCRDCS
GEOTEXTILE
4"- 8" QUARRY
SPALLS
R=25' MIN.
100'
M
I
N
.
EXISTI
N
G
R
O
A
D
15' MI
N.
NOTES:
C.3.2 MULCHING
2017 City of Renton Surface Water Design Manual 12/12/2016 C-113
Maintenance Standards
1. The thickness of the mulch cover must be maintained.
2. Any areas that experience erosion shall be re-mulched and/or protected with a net or blanket. If the erosion problem is drainage related, then the drainage problem shall be assessed and alternate drainage
such as interceptor swales may be needed to fix the problem and the eroded area re-mulched.
TABLE C.3.2.A MULCH STANDARDS AND GUIDELINES
Mulch
Material Quality Standards Application Rates Remarks
Straw Air-dried; free from
undesirable seed and
coarse material
2″–3″ thick; 2–3
bales per 1000 sf
or 2–3 tons per
acre
Cost-effective protection when applied with adequate
thickness. Hand-application generally requires greater
thickness than blown straw. Straw should be crimped to
avoid wind blow. The thickness of straw may be reduced
by half when used in conjunction with seeding.
Wood Fiber
Cellulose
No growth inhibiting
factors
Approx. 25–30 lbs
per 1,000 sf or
1,000–1,500 lbs
per acre
Shall be applied with hydromulcher. Shall not be used
without seed and tackifier unless the application rate is
at least doubled. Some wood fiber with very long fibers
can be effective at lower application rates and without
seed or tackifier.
Compost No visible water or dust
during handling. Must
be purchased from
supplier with Solid
Waste Handling Permit.
2″ thick min.;
approx. 100 tons
per acre (approx.
800 lbs per cubic
yard)
More effective control can be obtained by increasing
thickness to 3″. Excellent mulch for protecting final
grades until landscaping because it can be directly
seeded or tilled into soil as an amendment. Sources for
compost are available from the King County Commission
for Marketing Recyclable Materials at 206-296-4439.
Hydraulic
Matrices
(Bonded
Fiber Matrix
[BFM])
This mulch category
includes hydraulic
slurries composed of
wood fiber, paper fiber
or a combination of the
two held together by a
binding system. The
BFM shall be a mixture
of long wood fibers and
various bonding agents.
Apply at rates from
3,000 lbs per acre
to 4,000 lbs per
acre and based on
manufacturers
recommendations
The BFM shall not be applied immediately before, during
or immediately after rainfall so that the matrix will have
an opportunity to dry for 24 hours after installation.
Application rates beyond 2,500 pounds may interfere
with germination and are not usually recommended for
turf establishment. BFM is generally a matrix where all
fiber and binders are in one bag, rather than having to
mix components from various manufacturers to create a
matrix. BFMs can be installed via helicopter in remote
areas. They are approximately $1,000 per acre cheaper
to install.
Chipped Site
Vegetation
Average size shall be
several inches.
2″ minimum
thickness
This is a cost-effective way to dispose of debris from
clearing and grubbing, and it eliminates the problems
associated with burning. Generally, it should not be used
on slopes above approx. 10% because of its tendency to
be transported by runoff. It is not recommended within
200 feet of surface waters. If seeding is expected shortly
after mulch, the decomposition of the chipped vegetation
may tie up nutrients important to grass establishment.
SECTION C.3 CONSTRUCTION STORMWATER POLLUTION PREVENTION (CSWPP) MEASURES
12/12/2016 2017 City of Renton Surface Water Design Manual C-114
C.3.3 NETS AND BLANKETS
Purpose
Erosion control nets and blankets are intended to prevent erosion and hold seed and mulch in place on
steep slopes and in channels so that vegetation can become well established. In addition, some nets and
blankets can be used to permanently reinforce turf to protect drainage ways during high flows. Nets are
strands of material woven into an open, but high-tensile strength net (for example, jute matting). Blankets
are strands of material that are not tightly woven, but instead form a layer of interlocking fibers, typically
held together by a biodegradable or photodegradable netting (for example, excelsior or straw blankets).
They generally have lower tensile strength than nets, but cover the ground more completely. Coir (coconut
fiber) fabric comes as both nets and blankets.
Conditions of Use
Erosion control nets and blankets should be used:
1. For permanent stabilization of slopes 2H:1V or greater and with more than 10 feet of vertical relief.
2. In conjunction with seed for final stabilization of a slope, not for temporary cover. However, they may
be used for temporary applications as long as the product is not damaged by repeated handling. In fact,
this method of slope protection is superior to plastic sheeting, which generates high-velocity runoff.
3. For drainage ditches and swales (highly recommended). The application of appropriate netting or
blanket to drainage ditches and swales can protect bare soil from channelized runoff while vegetation
is established. Nets and blankets also can capture a great deal of sediment due to their open, porous
structure. Synthetic nets and blankets may be used to permanently stabilize channels and may provide
a cost-effective, environmentally preferable alternative to riprap.
Design and Installation Specifications
1. See Figure C.3.3.A and Figure C.3.3.B for typical orientation and installation of nettings and blankets.
Note: Installation is critical to the effectiveness of these products. If good ground contact is not
achieved, runoff can concentrate under the product, resulting in significant erosion.
2. With the variety of products available, it is impossible to cover all the details of appropriate use and
installation. Therefore, it is critical that the design engineer thoroughly consults the manufacturer’s
information and that a site visit takes place in order to ensure that the product specified is
appropriate.
3. Jute matting must be used in conjunction with mulch. Excelsior, woven straw blankets, and coir
(coconut fiber) blankets may be installed without mulch. There are many other types of erosion
control nets and blankets on the market that may be appropriate in certain circumstances. Other
types of products will have to be evaluated individually. In general, most nets (e.g., jute matting)
require mulch in order to prevent erosion because they have a fairly open structure. Blankets typically
do not require mulch because they usually provide complete protection of the surface.
4. Purely synthetic blankets are allowed but shall only be used for long-term stabilization of waterways.
The organic blankets authorized above are better for slope protection and short-term waterway
protection because they retain moisture and provide organic matter to the soil, substantially improving
the speed and success of re-vegetation.
Maintenance Standards
1. Good contact with the ground must be maintained, and there must not be erosion beneath the net or
blanket.
C.3.3 NETS AND BLANKETS
2017 City of Renton Surface Water Design Manual 12/12/2016 C-115
2. Any areas of the net or blanket that are damaged or not in close contact with the ground shall be repaired and stapled.
3. If erosion occurs due to poorly controlled drainage, the problem shall be fixed and the eroded area
protected.
FIGURE C.3.3.A WATERWAY INSTALLATION
FIGURE C.3.3.B SLOPE INSTALLATION
•DO NOT STRETCH BLANKETS/MATTINGS TIGHT - ALLOW THE ROLLSTO MOLD TO ANY IRREGULARITIES.
•SLOPE SURFACE SHALL BE SMOOTH BEFORE PLACEMENT FOR
PROPER SOIL CONTACT.
•ANCHOR, STAPLE, AND INSTALL CHECK SLOTS AS PERMANUFACTURER'S RECOMMENDATIONS.
•AVOID JOINING MATERIAL IN THE CENTER OF THE DITCH.
•LIME, FERTILIZE AND SEED BEFORE INSTALLATION.
MIN.4" OVERLAP'
MIN.6"
OVERLAP
SLOPE SURFACE SHALL BE SMOOTH BEFOREPLACEMENT FOR PROPER SOIL CONTACT
STAPLING PATTERN AS PER
MANUFACTURER'S RECOMMENDATION
MIN. 2" OVERLAP
LIME, FERTILIZE AND SEED BEFOREINSTALLATION. PLANTING OF SHRUBS, TREES,
ETC. SHOULD OCCUR AFTER INSTALLATION
DO NOT STRETCH BLANKETS/MATTINGS TIGHT - ALLOWTHE ROLLS TO MOLD TO ANY IRREGULARITIES
FOR SLOPES LESS THAN 3H:1V, ROLLS MAY BE PLACED
IN HORIZONTAL STRIPS
BRING MATERIAL DOWN TO A LEVELAREA, TURN THE END UNDER 4" AND
STAPLE AT 12" INTERVALS
ANCHOR IN 6"x6" MIN.
TRENCH AND STAPLE
AT 12" INTERVALS
STAPLE OVERLAPS
MAX. 5' SPACING
IF THERE IS A BERM AT THE
TOP OF SLOPE, ANCHORUPSLOPE OF THE BERM
MIN. 6" OVERLAP
SECTION C.3 CONSTRUCTION STORMWATER POLLUTION PREVENTION (CSWPP) MEASURES
12/12/2016 2017 City of Renton Surface Water Design Manual C-116
C.3.4 PLASTIC COVERING
Purpose
Plastic covering provides immediate, short-term erosion protection to slopes and disturbed areas.
Conditions of Use
1. Plastic covering may be used on disturbed areas that require cover measures for less than 30 days.
2. Plastic is particularly useful for protecting cut and fill slopes and stockpiles. Note: The relatively rapid
breakdown of most polyethylene sheeting makes it unsuitable for long-term applications.
3. Clear plastic sheeting may be used over newly-seeded areas to create a greenhouse effect and
encourage grass growth. Clear plastic should not be used for this purpose during the summer months
because the resulting high temperatures can kill the grass.
4. Due to rapid runoff caused by plastic sheeting, this method shall not be used upslope of areas that
might be adversely impacted by concentrated runoff. Such areas include steep and/or unstable slopes.
Note: There have been many problems with plastic, usually attributable to poor installation and
maintenance. However, the material itself can cause problems, even when correctly installed and
maintained, because it generates high-velocity runoff and breaks down quickly due to ultraviolet
radiation. In addition, if the plastic is not completely removed, it can clog drainage system inlets and
outlets. It is highly recommended that alternatives to plastic sheeting be used whenever possible and that
its use be limited.
Design and Installation Specifications
1. See Figure C.3.4.A for details.
2. Plastic sheeting shall have a minimum thickness of 0.06 millimeters.
3. If erosion at the toe of a slope is likely, a gravel berm, riprap, or other suitable protection shall be
installed at the toe of the slope in order to reduce the velocity of runoff.
FIGURE C.3.4.A PLASTIC COVERING
TIRES, SANDBAGS, OR
EQUIVALENT MAY BE USED
TO WEIGHT PLASTIC
SEAMS BETWEEN SHEETS
MUST OVERLAP A MINIMUM
OF 12" AND BE WEIGHTEDOR TAPED
TOE IN SHEETINGIN MINIMUM 4"X4"TRENCH
PROVIDE ENERGY DISSIPATIONAT TOE WHEN NEEDED
10' MAX.
10' MAX.
C.3.6 SILT FENCE
2017 City of Renton Surface Water Design Manual 12/12/2016 C-117
Maintenance Standards for Plastic Covering
1. Torn sheets must be replaced and open seams repaired.
2. If the plastic begins to deteriorate due to ultraviolet radiation, it must be completely removed and replaced.
3. When the plastic is no longer needed, it shall be completely removed.
C.3.5 MARK CLEARING LIMITS/MINIMIZE CLEARING
Purpose
Minimizing clearing is the most effective method of erosion control. Undisturbed vegetation intercepts and
slows rainwater. Plant roots hold soil in place, and dead vegetation on the ground acts as a mulch. Marking
clearing limits around existing or proposed on-site BMP areas helps protect their infiltrative soil
characteristics from construction activity.
Applications
Clearing limits shall be marked and clearing minimized on any site where significant areas of undisturbed
vegetation will be retained or where existing or proposed BMP/facility areas require protection from
construction activities.
Design Specifications
1. Minimizing clearing should be incorporated into the site design. Clearing limits must be marked on
the Small Site CSWPP plan.
2. On the ground, clearing limits must be clearly marked with brightly colored tape or plastic or metal
safety fencing. If tape is used, it should be supported by vegetation or stakes, and should be about 3 to
6 feet high and highly visible. BMP/facility areas to be protected should be marked with brightly
colored silt fence to add sedimentation protection. Equipment operators should be informed of areas of
vegetation that are to be left undisturbed and BMP/facility areas that are to be protected.
3. The duff layer, native top soil, and natural vegetation shall be retained in an undisturbed state to the
maximum extent practicable. If it is not practicable to retain the duff layer in place, it should be
stockpiled on-site, covered to prevent erosion, and replaced immediately upon completion of the
ground disturbing activities.
Maintenance
Fencing shall be inspected regularly and repaired or replaced as needed.
C.3.6 SILT FENCE
Purpose
Use of a silt fence reduces the transport of coarse sediment from a construction site by providing a temporary physical barrier to sediment and reducing the runoff velocities of overland flow.
Conditions of Use
1. Silt fence may be used downslope of all disturbed areas.
2. Silt fence is not intended to treat concentrated flows, nor is it intended to treat substantial amounts of overland flow. Any concentrated flows must be conveyed through the drainage system to a sediment
trap or pond.
C.3.10 SEEDING
2017 City of Renton Surface Water Design Manual 12/12/2016 C-127
C.3.10 SEEDING
Purpose
Seeding is intended to reduce erosion by stabilizing exposed soils. A well-established vegetative cover is
one of the most effective methods of reducing erosion.
Conditions of Use
1. Seeding shall be used throughout the project on disturbed areas that have reached final grade or that
will remain unworked for more than 30 days.
2. At the City’s discretion, seeding without mulch during the dry season is allowed even though it will
take more than seven days to develop an effective cover. Mulch is, however, recommended at all
times because it protects seeds from heat, moisture loss, and transport due to runoff.
3. Prior to the beginning of the wet season, all disturbed areas shall be reviewed to identify which ones
can be seeded in preparation for the winter rains. Disturbed areas shall be seeded within one week of
the beginning of the wet season. A sketch map of those areas to be seeded and those areas to remain
uncovered shall be submitted to the CED inspector. The CED inspector may require seeding of
additional areas in order to protect surface waters, adjacent properties, or drainage facilities.
4. At final site stabilization, all disturbed areas not otherwise vegetated or stabilized shall be seeded and
mulched.
Design and Installation Specifications
1. The best time to seed is fall (late September to October) or in spring (mid-March to June). Irrigation
is required during the first summer following installation if seeding occurs in spring or summer or
during prolonged dry times of year. Areas may also be seeded during the winter months, but it may
take additional spring seeding applications to develop a dense groundcover due to cold temperatures.
The application and maintenance of mulch is critical for winter seeding.
2. To prevent seed from being washed away, confirm that all required surface water control measures
have been installed.
3. The seedbed should not be compacted because soils that are well compacted will not vegetate as
quickly or thoroughly.
4. In general, 10-20-20 N-P-K (nitrogen-phosphorus-potassium) fertilizer may be used at a rate of
90 pounds per acre. Slow-release fertilizers are preferred because they are more efficient and have
fewer environmental impacts. It is recommended that areas being seeded for final landscaping conduct
soil tests to determine the exact type and quantity of fertilizer needed. This will prevent the over-
application of fertilizer. Disturbed areas within 200 feet of water bodies and wetlands must use slow-
release low-phosphorus fertilizer (typical proportions 3-1-2 N-P-K).
5. The following requirements apply to mulching:
a) Mulch is always required for seeding slopes greater than 3H:1V (see Section D.4.2.1).
b) If seeding during the wet season, mulch is required.
c) The use of mulch may be required during the dry season at the City’s discretion if grass growth is
expected to be slow, the soils are highly erodible due to soil type or gradient, there is a water body
close to the disturbed area, or significant precipitation is anticipated before the grass will provide
effective cover.
d) Mulch may be applied on top of the seed or simultaneously by hydroseeding.
SECTION C.3 CONSTRUCTION STORMWATER POLLUTION PREVENTION (CSWPP) MEASURES
12/12/2016 2017 City of Renton Surface Water Design Manual C-128
6. Hydroseeding is allowed as long as tackifier is included. Hydroseeding with wood fiber mulch is adequate during the dry season. During the wet season, the application rate shall be doubled because
the mulch and tackifier used in hydroseeding break down fairly rapidly.
7. Areas to be permanently landscaped shall use soil amendments. Good quality topsoil shall be tilled
into the top six inches to reduce the need for fertilizer and improve the overall soil quality. Most native soils will require the addition of four inches of well-rotted compost to be tilled into the soil to
provide a good quality topsoil. Compost used should meet specifications in Reference Section 11-C.
8. The seed mixes listed below in Table C.3.10.A and Table C.3.10.B include recommended mixes for
both temporary and permanent seeding. These mixes, with the exception of the wetland mix, shall be
applied at a rate of 80 to 100 seeds per square foot. Wet sites should apply 120 to 150 seeds per square
foot. Local suppliers should be consulted for information on current Pure Live Seed (PLS) rates and species specific seeds per pound in order to determine seed mix PLS pounds of seed per acre. The
appropriate mix depends on a variety of factors, including exposure, soil type, slope, and expected foot traffic. Alternative seed mixes approved by the City may be used.
TABLE C.3.10.A EROSION CONTROL SEED MIX
Common Name/Latin Name
% Species
Composition
Desired Seeds
per Square Foot
PLS
pounds/Acre
Spike bentgrass Agrostis exarata 6 9 0.1
California brome/Bromus carinatus 15 23 9.8
Tufted hairgrass/Deschampsia cespitosa 15 23 0.4
Blue wildrye/Elymus glaucus 18 27 10.7
California oatgrass/Danthonia californica 18 27 5.6
Native red fescue/Festuca rubra var. rubra 18 27 2.4
Meadow barley/Hordeum brachyantherum 10 15 7.7
TABLE C.3.10.B LANDSCAPING SEED MIX
Common Name/Latin Name
% Species
Composition
Desired Seeds
per Square Foot
PLS
pounds/Acre
Sideoats grama/Bouteloua curtipendula 20 30 6.8
California oatgrass/Danthonia californica 20 30 6.2
Native red fescue/Festuca rubra var. rubra 30 45 3.9
Prairie junegrass/Koeleria macrantha 30 45 0.8
Maintenance Standards for Seeding
1. Any seeded areas that fail to establish at least 80 percent cover within one month shall be reseeded. If
reseeding is ineffective, an alternate method, such as sodding or nets/blankets, shall be used. If winter
weather prevents adequate seed establishment and growth, this time limit may be relaxed at the
discretion of the City when critical areas would otherwise be protected.
2. After adequate cover is achieved, any areas that experience erosion shall be re-seeded and protected
by mulch. If the erosion problem is drainage related, the problem shall be fixed and the eroded area re-
seeded and protected by mulch.
3. Seeded areas shall be supplied with adequate moisture, but not watered to the extent that it causes
runoff.
D.2.1 ESC MEASURES
2017 City of Renton Surface Water Design Manual 12/12/2016 D-67
c) Discharge to the sanitary sewer discharge with approval from King County and the City of Renton if there is no other option, or
d) Use of a sedimentation bag with outfall to a ditch or swale for small volumes of localized
dewatering.
2. Clean, non-turbid dewatering water, such as well-point ground water, may be discharged via stable conveyance to systems tributary to surface waters, provided the dewatering flow does not cause
erosion or flooding of receiving waters.
3. Highly turbid or contaminated dewatering water (high pH or other) shall be handled separately
from stormwater. See Section D.2.2 , SWPPS Measures.
D.2.1.8 DUST CONTROL
Preventative measures to minimize the wind transport of soil shall be taken when a traffic hazard may be
created or when sediment transported by wind is likely to be deposited in water resources or adjacent properties.
Purpose: To prevent wind transport of dust from exposed soil surfaces onto roadways, drainage ways, and surface waters.
When to Install: Dust control shall be implemented when exposed soils are dry to the point that wind transport is possible and roadways, drainage ways, or surface waters are likely to be impacted. Dust
control measures may consist of chemical, structural, or mechanical methods.
Measures to Install: Water is the most common dust control (or palliative) used in the area. When using
water for dust control, the exposed soils shall be sprayed until wet, but runoff shall not be generated by spraying. Calcium chloride, Magnesium chloride, Lignin derivatives, Tree Resin Emulsions, and Synthetic
Polymer Emulsions may also be used for dust control. Exposed areas shall be re-sprayed as needed. Oil shall not be used for dust control. The following table lists many common dust control measures. Some of
the measures are not recommended for use in the City and must have prior approval prior to use from the CED inspector assigned to specific projects.
TABLE D.2.1.8.A DUST CONTROL MEASURES
Method Considerations Site Preparation
Recommended
Application Rate
Water -Most commonly used practice
-Evaporates quickly
-Lasts less than 1 day
For all liquid agents:
-Blade a small surface
-Crown or slope surface to avoid ponding
-Compact soils if needed
-Uniformly pre-wet at 0.03 – 0.3 gal/sq yd
-Apply solution under pressure. Overlap solution 6 – 12 inches
-Allow treated area to cure
0 – 4 hours
-Compact area after curing
-Apply second treatment before first
treatment becomes ineffective
0.125 gal/sq yd every 20 to 30 minutes
Salts Calcium Chloride
(CaCl)
-Restricts evaporation
-Lasts 6–12 months
-Can be corrosive
-Less effective in low humidity
-Can build up in soils and leach by rain
Apply 38% solution at 1.21L/m2 (0.27 gal/yd2) or as loose dry granules per manufacturer
SECTION D.2 GENERAL CSWPP REQUIREMENTS
12/12/2016 2017 City of Renton Surface Water Design Manual D-68
TABLE D.2.1.8.A DUST CONTROL MEASURES
Method Considerations Site Preparation
Recommended
Application Rate
Magnesium Chloride
(MgCl)
-Restricts evaporation
-Works at higher temperatures and lower
humidity than CaCl
-May be more costly than CaCl
Apply 26 – 32% solution at 2.3 L/m2 (0.5 gal/yd2)
Sodium
Chloride
(NaCl)
-Effective over smaller range of
conditions
-Less expensive
-Can be corrosive
-Less effective in low humidity
Per Manufacturer
Silicates -Generally expensive
-Available in small quantities
-Require Second application
Surfactants -High evaporation rates
-Effective for short time periods
-Must apply frequently
Copolymers -Forms semi-permeable transparent
crust
-Resists ultraviolet radiation and moisture induced breakdown
-Last 1 to 2 years
750 – 940 L/ha (80 –
100 gal/ac)
Petroleum Products -Used oil is prohibited as a dust control method
-Bind soil particles
-May hinder foliage growth
-Environmental and aesthetic concerns
-Higher cost
Use 57 – 63% resins as base. Apply at 750 –
940 L/ha (80–100 gal/ac)
Lignin Sulfonate -Paper industry waste product
-Acts as dispersing agent
-Best in dry climates
-Can be slippery
-Will decrease Dissolved Oxygen in
waterways therefore cannot be used adjacent to surface water systems
Loosen surface 25–50 mm (1–2 inches) Need 4–8% fines
Vegetable Oils -Coat grains of soils, so limited binding ability
-May become brittle
-Limited availability
Per Manufacturer
Spray on Adhesives -Available as organic or synthetic
-Effective on dry, hard soils
-Forms a crust
-Can last 3 to 4 years
Per Manufacturer
D.2.1.9 FLOW CONTROL
Surface water from disturbed areas must be routed through the project’s onsite flow control facility or
other provisions must made to prevent increases in the existing site conditions 2-year and 10-year runoff
peaks discharging from the project site during construction.
Purpose: The purpose of surface water flow control is to mitigate increases in runoff peaks that occur
during construction as a result of clearing vegetation, compacting the soil, and adding impervious surface.
Such increases can cause or aggravate downstream flooding and erosion.
SECTION D.2 GENERAL CSWPP REQUIREMENTS
12/12/2016 2017 City of Renton Surface Water Design Manual D-72
• Filtration and chemical treatment of construction water to facilitate disposal or discharge to approved locations
• Reporting requirements and documentation availability for specific BMP processes
Additionally, several of the ESC BMPs described in Section D.2.1 can be applicable to the SWPPS plan, e.g., use of cover, fencing and access protection to protect temporary materials storage locations. The applicant’s material supplier may be a resource (subject to City approval) for BMPs to address specific project applications or proposals. Conditions of approval on adjustments may also specify additional requirements for the SWPPS plan.
D.2.2.1 CONCRETE HANDLING
Purpose
Concrete work can generate process water and slurry that contain fine particles and high pH, both of which can violate water quality standards in the receiving water. Concrete spillage or concrete discharge to surface waters of the State is prohibited. Use this BMP to minimize and eliminate concrete, concrete process water, and concrete slurry from entering waters of the state.
Conditions of Use
Any time concrete is used, utilize these management practices. Concrete construction projects include, but are not limited to, curbs, sidewalks, roads, bridges, foundations, floors, stormwater vaults, retaining walls, driveways and runways.
Design and Installation Specifications
1. Ensure that washout of concrete trucks, chutes, pumps, and internals is performed at an approved off-
site location or in designated concrete washout areas. Do not wash out concrete trucks onto the ground, or into storm drains, open ditches, streets, or streams. Refer to BMP D.2.2.2 for information on concrete washout areas.
2. Return unused concrete remaining in the truck and pump to the originating batch plant for recycling. Do not dump excess concrete on site, except in designated concrete washout areas.
3. Wash off hand tools including, but not limited to, screeds, shovels, rakes, floats, and trowels into formed areas only.
4. Wash equipment difficult to move, such as concrete pavers in areas that do not directly drain to natural or constructed stormwater conveyances.
5. Do not allow washdown from areas, such as concrete aggregate driveways, to drain directly to natural or constructed stormwater conveyances.
6. Contain washwater and leftover product in a lined container when no formed areas are available,. Dispose of contained concrete in a manner that does not violate ground water or surface water quality standards.
7. Always use forms or solid barriers for concrete pours, such as pilings, within 15-feet of surface waters.
8. Refer to BMPs D.2.2.7 and D.2.2.8 for pH adjustment requirements.
9. Refer to the Construction Stormwater General Permit for pH monitoring requirements if the project
involves one of the following activities:
• Significant concrete work (greater than 1,000 cubic yards poured concrete or recycled concrete used over the life of a project).
• The use of engineered soils amended with (but not limited to) Portland cement-treated base, cement kiln dust or fly ash.
• Discharging stormwater to segments of water bodies on the 303(d) list (Category 5) for high pH.
Maintenance Standards
Check containers for holes in the liner daily during concrete pours and repair the same day.
SECTION D.2 GENERAL CSWPP REQUIREMENTS
12/12/2016 2017 City of Renton Surface Water Design Manual D-78
D.2.2.3 SAWCUTTING AND SURFACING POLLUTION PREVENTION
Purpose
Sawcutting and surfacing operations generate slurry and process water that contains fine particles and high
pH (concrete cutting), both of which can violate the water quality standards in the receiving water. Concrete spillage or concrete discharge to surface waters of the State is prohibited. Use this BMP to
minimize and eliminate process water and slurry created through sawcutting or surfacing from entering waters of the State.
Conditions of Use
Utilize these management practices anytime sawcutting or surfacing operations take place. Sawcutting and
surfacing operations include, but are not limited to, sawing, coring, grinding, roughening, hydro-demolition, bridge and road surfacing
Design and Installation Specifications
1. Vacuum slurry and cuttings during cutting and surfacing operations.
2. Slurry and cuttings shall not remain on permanent concrete or asphalt pavement overnight.
3. Slurry and cuttings shall not drain to any natural or constructed drainage conveyance including
stormwater systems. This may require temporarily blocking catch basins.
4. Dispose of collected slurry and cuttings in a manner that does not violate ground water or surface
water quality standards.
5. Do not allow process water generated during hydro-demolition, surface roughening or similar
operations to drain to any natural or constructed drainage conveyance including stormwater systems. Dispose process water in a manner that does not violate ground water or surface water quality
standards.
6. Handle and dispose cleaning waste material and demolition debris in a manner that does not cause
contamination of water. Dispose of sweeping material from a pick-up sweeper at an appropriate disposal site.
Maintenance Standards
Continually monitor operations to determine whether slurry, cuttings, or process water could enter waters
of the state. If inspections show that a violation of water quality standards could occur, stop operations and immediately implement preventive measures such as berms, barriers, secondary containment, and vacuum
trucks.
D.2.2.4 MATERIAL DELIVERY, STORAGE, AND CONTAINMENT
Purpose
Prevent, reduce, or eliminate the discharge of pollutants to the stormwater system or watercourses from
material delivery and storage. Minimize the storage of hazardous materials onsite, store materials in a
designated area, and install secondary containment.
Conditions of Use
These procedures are suitable for use at all construction sites with delivery and storage of the following
materials:
• Petroleum products such as fuel, oil and grease
• Soil stabilizers and binders (e.g., Polyacrylamide)
• Fertilizers, pesticides and herbicides
• Detergents
• Asphalt and concrete compounds
D.2.2 SWPPS MEASURES
2017 City of Renton Surface Water Design Manual 12/12/2016 D-79
• Hazardous chemicals such as acids, lime, adhesives, paints, solvents and curing compounds
• Any other material that may be detrimental if released to the environment
Design and Installation Specifications
The following steps should be taken to minimize risk:
1. Temporary storage area should be located away from vehicular traffic, near the construction
entrance(s), and away from waterways or storm drains.
2. Material Safety Data Sheets (MSDS) should be supplied for all materials stored. Chemicals should be
kept in their original labeled containers.
3. Hazardous material storage onsite should be minimized.
4. Hazardous materials should be handled as infrequently as possible.
5. During the wet weather season (October 1 – April 30), consider storing materials in a covered area.
6. Materials should be stored in secondary containments, such as earthen dike, horse trough, or even a
children’s wading pool for non-reactive materials such as detergents, oil, grease, and paints. Small
amounts of material may be secondarily contained in “bus boy” trays or concrete mixing trays.
7. Do not store chemicals, drums, or bagged materials directly on the ground. Place these items on a
pallet and, when possible, and within secondary containment.
8. If drums must be kept uncovered, store them at a slight angle to reduce ponding of rainwater on the
lids to reduce corrosion. Domed plastic covers are inexpensive and snap to the top of drums,
preventing water from collecting.
Material Storage Areas and Secondary Containment Practices:
1. Liquids, petroleum products, and substances listed in 40 CFR Parts 110, 117, or 302 shall be stored in
approved containers and drums and shall not be overfilled. Containers and drums shall be stored in
temporary secondary containment facilities.
2. Temporary secondary containment facilities shall provide for a spill containment volume able to
contain 10% of the total enclosed container volume of all containers, or 110% of the capacity of the
largest container within its boundary, whichever is greater.
3. Secondary containment facilities shall be impervious to the materials stored therein for a minimum
contact time of 72 hours.
4. Secondary containment facilities shall be maintained free of accumulated rainwater and spills. In the
event of spills or leaks, accumulated rainwater and spills shall be collected and placed into drums.
These liquids shall be handled as hazardous waste unless testing determines them to be non-
hazardous.
5. Sufficient separation should be provided between stored containers to allow for spill cleanup and
emergency response access.
6. During the wet weather season (October 1 – April 30), each secondary containment facility shall be
covered during non-working days, prior to and during rain events.
7. Keep material storage areas clean, organized and equipped with an ample supply of appropriate spill
clean-up material (spill kit).
8. The spill kit should include, at a minimum:
• 1-Water Resistant Nylon Bag
• 3-Oil Absorbent Socks 3″ x 4′
• 2-Oil Absorbent Socks 3″ x 10′
• 12-Oil Absorbent Pads 17″ x 19″
SECTION D.2 GENERAL CSWPP REQUIREMENTS
12/12/2016 2017 City of Renton Surface Water Design Manual D-80
• 1-Pair Splash Resistant Goggles
• 3-Pair Nitrile Gloves
• 10-Disposable Bags with Ties
• Instructions
D.2.2.5 CONSTRUCTION STORMWATER CHEMICAL TREATMENT
Purpose
This BMP applies when using stormwater chemicals in batch treatment or flow-through treatment.
Turbidity is difficult to control once fine particles are suspended in stormwater runoff from a construction
site. Sedimentation ponds are effective at removing larger particulate matter by gravity settling, but are
ineffective at removing smaller particulates such as clay and fine silt. Traditional erosion and sediment
control BMPs may not be adequate to ensure compliance with the water quality standards for turbidity in
receiving water.
Chemical treatment can reliably provide exceptional reductions of turbidity and associated pollutants.
Chemical treatment may be required to meet turbidity stormwater discharge requirements, especially when
construction is to proceed through the wet season.
Conditions of Use
Formal written approval from Ecology is required for the use of chemical treatment regardless of
site size. The City also requires review and approval. When approved, the chemical treatment systems
must be included in the SWPPS portion of the project’s CSWPP.
Design and Installation Specifications
Coagulation and flocculation have been used for over a century to treat water. It is used less frequently for
the treatment of wastewater. The use of coagulation and flocculation for treating stormwater is a very
recent application. Experience with the treatment of water and wastewater has resulted in a basic
understanding of the process, in particular factors that affect performance. This experience can provide
insights as to how to most effectively design and operate similar systems in the treatment of stormwater.
Fine particles suspended in water give it a milky appearance, measured as turbidity. Their small size, often
much less than 1 μm in diameter, give them a very large surface area relative to their volume. These fine
particles typically carry a negative surface charge. Largely because of these two factors, small size and
negative charge, these particles tend to stay in suspension for extended periods of time. Thus, removal is
not practical by gravity settling. These are called stable suspensions. Polymers, as well as inorganic
chemicals such as alum, speed the process of clarification. The added chemical destabilizes the suspension
and causes the smaller particles to agglomerate. The process consists of three steps: coagulation,
flocculation, and settling or clarification. Each step is explained below as well as the factors that affect the
efficiency of the process.
Coagulation: Coagulation is the first step. It is the process by which negative charges on the fine particles
that prevent their agglomeration are disrupted. Chemical addition is one method of destabilizing the
suspension, and polymers are one class of chemicals that are generally effective. Chemicals that are used
for this purpose are called coagulants. Coagulation is complete when the suspension is destabilized by the
neutralization of the negative charges. Coagulants perform best when they are thoroughly and evenly
dispersed under relatively intense mixing. This rapid mixing involves adding the coagulant in a manner
that promotes rapid dispersion, followed by a short time period for destabilization of the particle
suspension. The particles are still very small and are not readily separated by clarification until
flocculation occurs.
Page |33
C. Correspondence
Page |34
D. Site Inspection Form
Construction Stormwater Site Inspection Form
Page 1
Project Name Permit # Inspection Date Time
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 erosion/sediment controls Clearing/Demo/Grading Infrastructure/storm/roads
Concrete pours Vertical Construction/buildings Utilities
Offsite improvements Site temporary stabilized Final stabilization
C. Questions:
1. Were all areas of construction and discharge points inspected? Yes No
2. Did you observe the presence of suspended sediment, turbidity, discoloration, or oil sheen Yes No
3. Was a water quality sample taken during inspection? (refer to permit conditions S4 & S5) Yes No
4. Was there a turbid discharge 250 NTU or greater, or Transparency 6 cm or less?* Yes No
5. If yes to #4 was it reported to Ecology? 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
Construction Stormwater Site Inspection Form
Page 2
D. Check the observed status of all items. Provide “Action Required “details and dates.
Element # Inspection BMPs
Inspected
BMP needs
maintenance
BMP
failed
Action
required
(describe in
section F)
yes no n/a
1
Clearing
Limits
Before beginning land disturbing
activities are all clearing limits,
natural resource areas (streams,
wetlands, buffers, trees) protected
with barriers or similar BMPs? (high
visibility recommended)
2
Construction
Access
Construction access is stabilized
with quarry spalls or equivalent
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
Control Flow
Rates
Are flow control measures installed
to control stormwater 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
Sediment
Controls
All perimeter sediment controls
(e.g. silt fence, wattles, compost
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
Stabilize
Soils
Have exposed un‐worked soils
been stabilized with effective BMP
to prevent erosion and sediment
deposition?
Construction Stormwater Site Inspection Form
Page 3
Element # Inspection BMPs
Inspected
BMP needs
maintenance
BMP
failed
Action
required
(describe in
section F)
yes no n/a
5
Stabilize Soils
Cont.
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?
6
Protect
Slopes
Has stormwater and ground water
been diverted away from slopes and
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
Drain Inlets
Storm drain inlets made operable
during construction are protected.
Are existing storm drains within the
influence of the project protected?
8
Stabilize
Channel and
Outlets
Have all on‐site conveyance channels
been designed, constructed and
stabilized to prevent erosion from
expected peak flows?
Is stabilization, including armoring
material, adequate to prevent erosion
of outlets, adjacent stream banks,
slopes and downstream conveyance
systems?
9
Control
Pollutants
Are waste materials and demolition
debris handled and disposed of to
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?
Construction Stormwater Site Inspection Form
Page 4
Element # Inspection BMPs
Inspected
BMP needs
maintenance
BMP
failed
Action
required
(describe in
section F)
yes no n/a
9
Cont.
Wheel wash wastewater is handled
and disposed of properly.
10
Control
Dewatering
Concrete washout in designated areas.
No washout or excess concrete 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
Maintain
BMP
Are all temporary and permanent
erosion and sediment control BMPs
maintained to perform as intended?
12
Manage the
Project
Has the project been phased to the
maximum degree practicable?
Has regular inspection, monitoring and
maintenance been performed as
required by the permit?
Has the SWPPP been updated,
implemented and records maintained?
E. Check all areas that have been inspected.
All in place BMPs All disturbed soils All concrete wash out area All material storage areas
All discharge locations All equipment storage areas All construction 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: (print) (Signature) Date:
Title/Qualification of Inspector:
Page |35
E. Construction Stormwater General Permit (CSWGP)
Notice of Intent
Construction Stormwater General Permit
Permittee
First Name:Last Name:
Organization Name:
Honorific:
Title:
Mailing Address:
City:State:Zip Code:
Primary Phone:Secondary Phone:
Email:
UBI Number:
Kevin Rech
TH Infill, LLC Owner
2630 116th Ave NE Ste 200
98004-1459
kevin@terreneventures.com
Bellevue WA
425-822-8848
Site Contact
First Name:Last Name:
Organization Name:
Honorific:
Title:
Mailing Address:
City:State:Zip Code:
Primary Phone:Secondary Phone:
Email:
UBI Number:
Charlie Johnson
TH Infill, LLC
2630 116th Ave NE Ste 200
98004-1459
charlietj2000@icloud.com
Bellevue WA
206-850-5336
Site Owner
First Name:Last Name:
Organization Name:
Honorific:
Title:
Mailing Address:
City:State:Zip Code:
Primary Phone:Secondary Phone:
Email:
UBI Number:
Kevin Rech
TH Infill, LLC Owner
2630 116th Ave NE Ste 200
98004-1459
kevin@terreneventures.com
Bellevue WA
425-822-8848
II. Electronic Discharge Monitoring Reporting
I. Contact Information
You must submit monthly discharge monitoring reports using Ecology¶s Electronic Discharge Monitoring Reporting
(WQWebDMR) system. To sign up for WQWebDMR, or to register a new site, go to ecology.wa.gov/Regulations-
Permits/Permits-certifications/Stormwater-general-permits, and click on the ³Construction Stormwater´link. You will find
information on WQWebDMR under the ³WQWebDMR and PARIS´link on the right-hand side. If you are unable to submit
your DMRs electronically, you may contact Ecology to request a waiver. Ecology will generally only grant waiver requests
to those permittees without internet access. Only a permittee or representative, designated in writing, may request
access to or a waiver from WQWebDMR. To have the ability to use the system immediately, you must submit the
Electronic Signature Agreement with your application. If you have questions on this process, contact Ecology¶s
WQWebDMR staff at WQWebPortal@ecy.wa.gov or 360-407-7097.
NOI
:
25493NewRenewalPermit Number:XApplication Type:
Page 1 of 4Submission ID: 1692229
III. Site Information
Site Project Name:Pegasus Lot 4
Street Address or Location Description:6692 264TH AVE NE
City:County:Zip Code:Redmond King 98053
Latitude:-121.986146Longitude:47.663833
X
Type of Construction Activity:
Residential
Industrial
Highway or Road (city, county, state)
Commercial
Utilities (specify):
Other (specify):
Site Acreage
Total site/project size:7.53 acres
2.64 acres
Estimated project start date:Estimated project completion date:11/1/2019 5/29/2020
IV. Existing Site Conditions
1. Are you aware of contaminated soils on this site?XYes No
2. Are you aware of groundwater contamination located within the site boundary?XYes No
3. If you answered yes to question 1 or 2, will any contaminated soils be distrubed or will any
contaminated groundwater be discharged due to the proposed construction activity?Yes No
If yes, please provide detailed information (as known and readily available) on the nature and extent of the contamination
(concentrations, locations, and depth) as well as pollution prevention and/or treatment Best Management Practices
(BMPs) proposed to control the discharge of soil and/or groundwater contaminants in stormwater. This should include
information that would be included in related portions of the Stormwater Pollution Prevention Plan (SWPPP) that describe
how contaminated and potentially contaminated construction stormwater and dewatering water will be managed. You
may attach this information separately, if needed
V. Stormwater Pollution Prevention Plan (SWPPP)
You must develop a SWPPP prior to starting construction. Do not submit your SWPPP with your application. If you
answered yes to the questions in Part IV, please submit the information that would be included in related portions of the
SWPPP that describe how contaminated and potentially contaminated construction stormwater and dewatering water will
be managed.
You must use the BMPs listed in the Stormwater Management Manual for Western Washington or the Stormwater
Management Manual for Eastern Washington or other manuals approved by Ecology. Alternatively, you may use
demonstrably equivalent BMPs on the basis of permit condition S9.C.4. If you intend to use a BMP at your site that is not
included in these manuals, but that you believe meets the definition of a demonstrably equivalent BMP, you must notify
the appropriate regional office. (See Definitions in the Construction Stormwater General Permit).*
http://ecology.wa.gov/Regulations-Permits/Permits-certifications/Stormwater-general-permits/Construction-stormwater-
permit#contacts
VI. Best Management Practices (BMPs)
Other Permits
None
Total disturbed area:
Total area of soil disturbance for your site/project over the life of
the project. Include grading, equipment staging, excavation,
borrow pit, material storage areas, dump areas, haul roads, side-
cast areas, off-site construction support areas, and all other soil
disturbance acreage associated with the project.
Will 1,000 cubic yards or more of poured concrete or recycled concrete be used over the
life of the project? XYes No
Page 2 of 4Submission ID: 1692229
*Note that if you receive permit coverage without indicating the preference for a demonstrably equivalent BMP and later decide to use one, you must
provide Ecology with notice of the selection of an equivalent BMP no less than 60 days before the intended use of the equivalent BMP.
VII. Discharge/Receiving Water Information
Indicate whether your site¶s stormwater and/or dewatering water could enter surface waters, directly and/or indirectly:
X Water will discharge directly or indirectly (through a storm drain system or roadside ditch) into one or more surface
waterbodies (wetlands, creeks, lakes, and all other surface waters and water courses).
If your discharge is to a storm sewer system, provide the name of the operator of the storm sewer
system:
Water will discharge to ground with 100% infiltration, with no potential to reach surface waters under any conditions.
If your project includes dewatering, you must include dewatering plans and discharge locations in your site Stormwater
Pollution Prevention Plan.
Location of Discharge into Surface Waterbody
Outfall
Number
Outfall Description Surface Waterbody Name Outfall Type Latitude Longitude
001A West 1 Unnamed tributary Surface Water Body 47.661385 -121.98967
002A West 2 Ames Lake Surface Water Body 47.642404 -121.960817
001B East 1 Unnamed tributary Surface Water Body 47.663121 -121.974421
002B East 2 Ames Creek Surface Water Body 47.665579 -121.969733
003B East 3 Snoqualmie River Surface Water Body 47.682081 -121.978278
VIII. State Environmental Policy Act (SEPA)
This Notice of Intent (NOI) is incomplete and cannot be approved until the applicable SEPA requirements under Chapter
197-11 WAC are met.
Who is the SEPA lead agency on your site?
Has the SEPA lead agency issued a final decision on your checklist?
If No: The NOI is incomplete. Ecology will hold the application until a final SEPA decision is made or the
Construction Stormwater NOI public comment period ends, whichever is later. You must notify Ecology once the
lead agency has issued a determination.
If Yes: Type of SEPA decision issued:
Date of final SEPA decision:
Date when all SEPA-related comment & appeal periods ended or will end:
King County
Yes No X Exempt
If Exempt:
X
Watershed Restoration & Fish Habitat Enhancement Exemption (RCW 43.21C.0382).
Planned Action Exemption (RCW 43.21C.031).
Categorical Exemption. Under what section of the SEPA Rule (WAC 197-11-800) is it exempt?
Infill Development Exemption (RCW 43.21C.229).
Section:WAC 197-11-800(1)(b)(i)
IX. Public Notice
Page 3 of 4Submission ID: 1692229
Newspaper Name First Public Notice Date Second Public Notice Date
Daily Journal of Commerce 10/7/2019 10/14/2019
You must publish a public notice at least once a week for two consecutive weeks with seven days between
publications, in at least a single newspaper of general circulation in the county in which the facility is located. Ecology
cannot grant permit coverage sooner than the end of the 30-day public comment period, which begins on the date of the
second public notice.
X. Certification of Permittees
³I certify under penalty of law that this document and all attachments were prepared under my direction or
supervision in accordance with a system designed to assure that qualified personnel properly gather and
evaluate the information submitted. Based on my inquiry of the person or persons who manage the system or
those directly responsible for gathering the information, the information submitted is, to the best of my
knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for
submitting false information, including the possibility of fine and imprisonment for knowing violations.´
Permittee Signature Date
Page 4 of 4Submission ID: 1692229
Page |36
F. 303(d) List Waterbodies / TMDL Waterbodies Information
N/A
Page |37
G. Contaminated Site Information
N/A
Page |38
H. Engineering Calculations
N/A