APPROVED STM RESUB 2-BLD2023-1355+SWPPP+7.18.2024_3.01.37_PM+4387640BLD2023-1355
RESUB
7.18.2024
CITY OF EDMONDS
DEVELOPMENT
SERVICES
DEPARTMENT
Construction Stormwater General Permit (CSWGP)
Stormwater Pollution Prevention Plan
(SWPPP)
for
Fulkerson
Prepared for:
Department of Ecology
Northwest Region
Permittee / Owner
Developer
Operator / Contractor
Signature Homes by Village
Life, LLC
Signature Homes by Village
Life, LLC
Signature Homes by Village
Life, LLC
Project Address:
8503 200TH ST SW EDMONDS, WA 98026
Certified Erosion and Sediment Control Lead (CESCL)
Name
Organization
Contact Phone Number
To Be Determined
To Be Determined
To Be Determined
SWPPP Prepared By
Name
Organization
Contact Phone Number
Drew Harris, RE
Momentum Civil
425.788.4111
SWPPP Preparation Date
03/21 /2024
Project Construction Dates
Activity / Phase
Start Date
End Date
Site Construction
09/01/2024
06/01/2025
COMPLIES WITH APPLICABLE
CITY STORMWATER CODE
11 /27/2024
List of Acronyms and Abbreviations
Acronym / Abbreviation Explanation
303(d)
Section of the Clean Water Act pertaining to Impaired Waterbodies
BFO
Bellingham Field Office of the Department of Ecology
BMP(s)
Best Management Practice(s)
CESCL
Certified Erosion and Sediment Control Lead
COz
Carbon Dioxide
CRO
Central Regional Office of the Department of Ecology
CSWGP
Construction Stormwater General Permit
CWA
Clean Water Act
DMR
Discharge Monitoring Report
DO
Dissolved Oxygen
Ecology
Washington State Department of Ecology
EPA
United States Environmental Protection Agency
ERO
Eastern Regional Office of the Department of Ecology
ERTS
Environmental Report Tracking System
ESC
Erosion and Sediment Control
GUILD
General Use Level Designation
NPDES
National Pollutant Discharge Elimination System
NTU
Nephelometric Turbidity Units
NWRO
Northwest Regional Office of the Department of Ecology
pH
Power of Hydrogen
RCW
Revised Code of Washington
SPCC
Spill Prevention, Control, and Countermeasure
su
Standard Units
SWMMEW
Stormwater Management Manual for Eastern Washington
SWMMWW
Stormwater Management Manual for Western Washington
SWPPP
Stormwater Pollution Prevention Plan
TESC
Temporary Erosion and Sediment Control
SWRO
Southwest Regional Office of the Department of Ecology
TMDL
Total Maximum Daily Load
VFO
Vancouver Field Office of the Department of Ecology
WAC
Washington Administrative Code
WSDOT
Washington Department of Transportation
WWHM
Western Washington Hydrology Model
Project Information (1.0)
Project/Site Name: Fulkerson
Street/Location: 8503 200TH ST SW,
City: EDMONDS State: WA Zip code: 98026
Subdivision: N/A
Receiving waterbody: City Storm System
Existing Conditions (1.1)
Total acreage (including support activities such as off -site equipment staging yards, material
storage areas, borrow areas).
Total acreage: 0.35 Acre
Disturbed acreage: 0.35 Acre
Existing structures: 1 House, and 3 sheds onsite
Landscape topography: Slight slope to the southwest
Drainage patterns: Sheet flow to the southwest
Existing Vegetation: trees, shrubs, grasses
Critical Areas (wetlands, streams, high erosion risk, steep or difficult to stabilize slopes):
None
List of known impairments for 303(d) listed or Total Maximum Daily Load (TMDL) for the
receiving waterbody: There does not appear to be a 303(d) listed or TMDL water body
within the'/4 mile downstream analysis area.
Table 1 includes a list of suspected and/or known contaminants associated with the construction
activity.
Table 1 — Summary of Site Pollutant Constituents
Constituent
(Pollutant)
Location
Depth
Concentration
None known
N/A
N/A
N/A
Proposed Construction Activities (1.2)
Description of site development (example: subdivision):
Single family lot with new house, driveway and porch.
Description of construction activities (example: site preparation, demolition, excavation):
The project is expected to involve clearing of the property to install a house and
driveway.
Description of site drainage including flow from and onto adjacent properties. Must be consistent
with Site Map in Appendix A:
There will be a small amount of flow to discharge onto the northern property. This
stormwater will be from the remnants of the sheet flow BMP.
Description of final stabilization (example: extent of revegetation, paving, landscaping):
Installation of house, driveway, dispersion trench and landscaping.
Contaminated Site Information:
Proposed activities regarding contaminated soils or groundwater (example: on -site treatment
system, authorized sanitary sewer discharge):
No contaminated soils or groundwater have been identified on this site.
Construction Stormwater Best Management Practices (BMPs) (2.0)
The SWPPP is a living document reflecting current conditions and changes throughout the life
of the project. These changes may be informal (i.e. hand-written notes and deletions). Update
the SWPPP when the CESCL has noted a deficiency in BMPs or deviation from original design.
The 12 Elements (2.1)
Element 1: Preserve Vegetation / Mark Clearing Limits (2.1.1)
The clearing limits are expected to be delineated by an orange construction fence and
silt fence.
List and describe BMPs: BMP C233: Silt Fence
Installation Schedules: Prior to clearing activities
Inspection and Maintenance plan: Project CESCL
Responsible Staff: Project CESCL
Element 2: Establish Construction Access (2.1.2)
The proposed driveway and gravel construction entrance will be used for construction
access.
List and describe BMPs: BMP C105: Stabilized Construction Entrance/Exit
Installation Schedules: Prior to clearing activities
Inspection and Maintenance plan: Project CESCL
Responsible Staff: Project CESCL
Element 3: Control Flow Rates (2.1.3)
The Project is proposing a Sediment trap in the front yard to reduce the velocity and help
control flow rate.
Will you construct stormwater retention and/or detention facilities?
Yes
Will you use permanent infiltration ponds or other low impact development (example: rain
gardens, bio-retention, porous pavement) to control flow during construction?
No
List and describe BMPs
Installation Schedules:
BMP C240: Sediment Trap
During site work
Inspection and Maintenance plan: Project CESCL
Responsible Staff: Project CESCL
Element 4: Install Sediment Controls (2.1.4)
The Project is proposing a Sediment trap in the front yard to collect and store sediment
from sites during construction.
List and describe BMPs: BMP C240: Sediment Trap
Installation Schedules: As site clearing occurs
Inspection and Maintenance plan: Project CESCL
Responsible Staff: Project CESCL
Element 5: Stabilize Soils (2.1.5)
The project intends to strip and stockpile topsoil from within the excavation areas of the
R-Tank and house. This material will then be covered under plastic sheeting. This topsoil
will be respread after utility or foundation construction in order to maintain the
topsoil i ng/composting requirements for BMPT5.13. Hydroseeding or sodding will be
completed at the conclusion of construction. Seeding and mulching may be used on a
temporary basis for areas that will be left unworked for a significant period of time.
Select your region's table and delete the others.
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: September2024 End date: Feb 2025
Will you construct during the wet season?
Yes
List and describe BMPs: BMP C120: Temporary and Permanent Seeding
BMP C121: Mulching
BMP C123: Plastic Sheeting
BMP C124: Sodding
BMP C125: Topsoil i ng/Composti ng
BMPC140: Dust Control
Installation Schedules: As site clearing occurs
Inspection and Maintenance plan: Project CESCL
Responsible Staff: Project CESCL
Element 6: Protect Slopes (2.1.6)
The site is relatively flat and does not contain steep slopes.
Will steep slopes be present at the site during construction?
List and describe BMPs: N/A
Installation Schedules: N/A
Inspection and Maintenance plan: N/A
Responsible Staff:
Element 7: Protect Drain Inlets (2.1.7)
Storm drain inlet protection will be used on all nearby catch basins prior to the start of
construction as well as within new drainage features once they are installed.
List and describe BMPs: BMP C220: Storm Drain Inlet Protection
Installation Schedules: As site clearing occurs
Inspection and Maintenance plan: Project CESCL
Responsible Staff: Project CESCL
Element 8: Stabilize Channels and Outlets (2.1.8)
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.
The project does not propose any outlets to streams or other open channels that need to
be stabilized.
List and describe BMPs: N/A
Installation Schedules: N/A
Inspection and Maintenance plan: N/A
Responsible Staff:
Element 9: Control Pollutants (2.1.9)
The following pollutants are anticipated to be present on -site:
Table 2 — Pollutants
Pollutant (and source, if applicable)
Demolition Debris
Sawcutting Debris and concrete wash water
Construction vehicle fuel/oil/lubricants
All demolition debris shall be disposed of in an offsite location. Construction vehicle
fueling should be performed offsite to the extent practicable. Sawcutting debris shall be
vacuumed up immediately after work is completed. A concrete washout area shall be
maintained while concrete is poured onsite.
List and describe BMPs: BMP C151: Concrete Handling
BMP C152: Sawcut and Surface Pollution Prevention
BMP C153: Material Delivery, Storage and Containment
BMP C154: Concrete Washout Area
Installation Schedules: As Needed
Inspection and Maintenance plan: Project CESCL
Responsible Staff: Project CESCL
Will maintenance, fueling, and/or repair of heavy equipment and vehicles occur on -site?
No
Will wheel wash or tire bath system BMPs be used during construction?
No
Will pH -modifying sources be present on -site?
Yes If yes, check the source(s).
Table 3 — pH -Modifying Sources
None
x
Bulk cement
x
Cement kiln dust
x
Fly ash
Other cementitious materials
x
New concrete washing or curing waters
x
Waste streams generated from concrete grinding and sawing
x
Exposed aggregate processes
Dewatering concrete vaults
x
Concrete pumping and mixer washout waters
x
Recycled concrete
Other (i.e. calcium lignosulfate) [please describe]
Concrete trucks must not be washed out onto the ground, or into storm drains, open ditches,
streets, or streams. Excess concrete must not be dumped on -site, except in designated
concrete washout areas with appropriate BMPs installed.
Element 10: Control Dewatering (2.1.10)
No significant dewatering is expected on this site.
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
dewaterin
List and describe BMPs: N/A
Installation Schedules: N/A
Inspection and Maintenance plan:
Responsible Staff:
Element 11: Maintain BMPs (2.1.11)
All temporary and permanent Erosion and Sediment Control (ESC) BMPs shall be maintained
and repaired as needed to ensure continued performance of their intended function.
Maintenance and repair shall be conducted in accordance with each particular BMP
specification (see Volume 11 of the SWMMWW or Chapter 7 of the SWMMEW).
Visual monitoring of all BMPs installed at the site will be conducted at least once every calendar
week and within 24 hours of any stormwater or non-stormwater discharge from the site. If the
site becomes inactive and is temporarily stabilized, the inspection frequency may be reduced to
once every calendar month.
All temporary ESC BMPs shall be removed within 30 days after final site stabilization is
achieved or after the temporary BMPs are no longer needed.
Trapped sediment shall be stabilized on -site or removed. Disturbed soil resulting from removal
of either BMPs or vegetation shall be permanently stabilized.
Additionally, protection must be provided for all BMPs installed for the permanent control of
stormwater from sediment and compaction. BMPs that are to remain in place following
completion of construction shall be examined and restored to full operating condition. If
sediment enters these BMPs during construction, the sediment shall be removed and the facility
shall be returned to conditions specified in the construction documents.
Element 12: Manage the Project (2.1.12)
The project will be managed based on the following principles:
• Projects will be phased to the maximum extent practicable and seasonal work limitations
will be taken into account.
Inspection and monitoring:
o Inspection, maintenance and repair of all BMPs will occur as needed to ensure
performance of their intended function.
o Site inspections and monitoring will be conducted in accordance with Special
Condition S4 of the CSWGP. Sampling locations are indicated on the Site Map.
Sampling station(s) are located in accordance with applicable requirements of
the CSWGP.
• Maintain an updated SWPPP.
o The SWPPP will be updated, maintained, and implemented in accordance with
Special Conditions S3, S4, and S9 of the CSWGP.
As site work progresses the SWPPP will be modified routinely to reflect changing site
conditions. The SWPPP will be reviewed monthly to ensure the content is current.
Check all the management BMPs that apply at your site:
Table 5 — Management
x
Design the project to fit the existing topography, soils, and drainage patterns
x
Emphasize erosion control rather than sediment control
x
Minimize the extent and duration of the area exposed
x
Keep runoff velocities low
x
Retain sediment on -site
x
Thoroughly monitor site and maintain all ESC measures
x
Schedule major earthwork during the dry season
Other (please describe)
Element 13: Protect Low Impact Development (LID) BMPs (2.1.13)
This project will be using BMP T5.12 (Sheet Flow Dispersion) partially for the driveway.
No specific BMP's are proposed for protection of the dispersion area, as no infiltration is
proposed. However, the area will be topsoil amended as a part of the overall project.
Pollution Prevention Team (3.0)
Table 7 — Team Information
Title
Names
Phone Number
Certified Erosion and
Sediment Control Lead
(CESCL)
To be determined
TBD
Resident Engineer
Drew Harris
253.722.6059
Emergency Ecology
Contact
Northwest Region
425.649.7000
Emergency Permittee/
Owner Contact
TBD
TBD
Non -Emergency Owner
Contact
TBD
TBD
Monitoring Personnel
TBD
TBD
Ecology Regional Office
Northwest Region
425.649.7000
Monitoring and Sampling Requirements (4.0)
Monitoring includes visual inspection, sampling for water quality parameters of concern, and
documentation of the inspection and sampling findings in a site log book. A site log book will be
maintained for all on -site construction activities and will include:
• A record of the implementation of the SWPPP and other permit requirements
• Site inspections
• Stormwater sampling data
The site log book must be maintained on -site within reasonable access to the site and be made
available upon request to Ecology or the local jurisdiction.
Numeric effluent limits may be required for certain discharges to 303(d) listed waterbodies. See
CSWGP Special Condition S8 and Section 5 of this template.
Complete the following paragraph for sites that discharge to impaired waterbodies for fine
sediment, turbidity, phosphorus, or pH:
Site Inspection (4.1)
Site inspections will be conducted at least once every calendar week and within 24 hours
following any discharge from the site. For sites that are temporarily stabilized and inactive, the
required frequency is reduced to once per calendar month.
The discharge point(s) are indicated on the Site Map (see Appendix A) and in accordance with
the applicable requirements of the CSWGP.
Stormwater Quality Sampling (4.2)
Turbidity Sampling (4.2.1)
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
x
Turbidity Meter/Turbid i meter (required for disturbances 5 acres or greater in size)
x
I 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.
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.
https://www.ecology.wa.gov/About-us/Get-involved/Report-an-environmental-issue
• Central Region (Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan, Yakima):
(509) 575-2490
• Eastern Region (Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant,
Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, Whitman): (509) 329-3400
• Northwest Region (King, Kitsap, Island, San Juan, Skagit, Snohomish,
Whatcom): (425) 649-7000
• Southwest Region (Clallam, Clark, Cowlitz, Grays Harbor, Jefferson, Lewis,
Mason, Pacific, Pierce, Skamania, Thurston, Wahkiakum,): (360) 407-6300
2. Immediately begin the process to fully implement and maintain appropriate source
control and/or treatment BMPs as soon as possible. Address the problems within 10
days of the date the discharge exceeded the benchmark. If installation of necessary
treatment BMPs is not feasible within 10 days, Ecology may approve additional time
when the Permittee requests an extension within the initial 10-day response period
3. Document BMP implementation and maintenance in the site log book.
4. Continue to sample discharges daily until one of the following is true:
• Turbidity is 25 NTU (or lower).
• Transparency is 33 cm (or greater).
• Compliance with the water quality limit for turbidity is achieved.
0 1 - 5 NTU over background turbidity, if background is less than 50 NTU
0 1 % - 10% over background turbidity, if background is 50 NTU or greater
• The discharge stops or is eliminated.
pH Sampling (4.2.2)
pH monitoring is required for "Significant concrete work" (i.e. greater than 1000 cubic yards
poured concrete or recycled concrete over the life of the project).The use of engineered soils
(soil amendments including but not limited to Portland cement -treated base [CTB], cement kiln
dust [CKD] or fly ash) also requires pH monitoring.
For significant concrete work, pH sampling will start the first day concrete is poured and
continue until it is cured, typically three (3) weeks after the last pour.
For engineered soils 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 8 — pH Sampling Method
x
pH meter
x
pH test kit
x
Wide range pH indicator paper
Discharges to 303(d) or Total Maximum Daily Load (TMDL)
Waterbodies (5.0)
303(d) Listed Waterbodies (5.1)
Is the receiving water 303(d) (Category 5) listed for turbidity, fine sediment, phosphorus, or pH?
List the impairment(s):
TMDL Waterbodies (5.2)
The project does not appear to be directly tributary to a TMDL water body.
Reporting and Record Keeping (6.0)
Record Keeping (6.1)
Site Log Book (6.1.1)
A site log book will be maintained for all on -site construction activities and will include:
• A record of the implementation of the SWPPP and other permit requirements
• Site inspections
• Sample logs
Records Retention (6.1.2)
Records will be retained during the life of the project and for a minimum of three (3) years
following the termination of permit coverage in accordance with Special Condition S5.0 of the
CSWGP.
Permit documentation to be retained on -site:
• CSWGP
• Permit Coverage Letter
• SWPPP
• Site Log Book
Permit documentation will be provided within 14 days of receipt of a written request from
Ecology. A copy of the SWPPP or access to the SWPPP will be provided to the public when
requested in writing in accordance with Special Condition S5.G.2.b of the CSWGP.
Updating the SWPPP (6.1.3)
The SWPPP will be modified if:
• Found ineffective in eliminating or significantly minimizing pollutants in stormwater
discharges from the site.
• There is a change in design, construction, operation, or maintenance at the construction
site that has, or could have, a significant effect on the discharge of pollutants to waters
of the State.
The SWPPP will be modified within seven (7) days if inspection(s) or investigation(s) determine
additional or modified BMPs are necessary for compliance. An updated timeline for BMP
implementation will be prepared.
Reporting (6.2)
Discharge Monitoring Reports (6.2.1)
Cumulative soil disturbance is less than one (1) acre; therefore, Discharge Monitoring
Reports (DMRs) will not be submitted to Ecology because water quality sampling is not being
conducted at the site.
Notification of Noncompliance (6.2.2)
If any of the terms and conditions of the permit is not met, and the resulting noncompliance may
cause a threat to human health or the environment, the following actions will be taken:
1. Ecology will be notified within 24-hours of the failure to comply by calling the applicable
Regional office ERTS phone number (Regional office numbers listed below).
2. Immediate action will be taken to prevent the discharge/pollution or otherwise stop or
correct the noncompliance. If applicable, sampling and analysis of any noncompliance
will be repeated immediately and the results submitted to Ecology within five (5) days of
becoming aware of the violation.
3. A detailed written report describing the noncompliance will be submitted to Ecology
within five (5) days, unless requested earlier by Ecology.
Anytime turbidity sampling indicates turbidity is 250 NTUs or greater, or water transparency is 6
cm or less, the Ecology Regional office will be notified by phone within 24 hours of analysis as
required by Special Condition S5.A of the CSWGP.
• Central Region at (509) 575-2490 for Benton, Chelan, Douglas, Kittitas, Klickitat,
Okanogan, or Yakima County
• Eastern Region at (509) 329-3400 for Adams, Asotin, Columbia, Ferry, Franklin,
Garfield, Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, or Whitman
County
• Northwest Region at (425) 649-7000 for Island, King, Kitsap, San Juan, Skagit,
Snohomish, or Whatcom County
• Southwest Region at (360) 407-6300 for Clallam, Clark, Cowlitz, Grays Harbor,
Jefferson, Lewis, Mason, Pacific, Pierce, Skamania, Thurston, or Wahkiakum
Include the following information:
1. Your name and / Phone number
2. Permit number
3. City / County of project
4. Sample results
5. Date / Time of call
6. Date / Time of sample
7. Project name
In accordance with Special Condition S4.D.5.b of the CSWGP, the Ecology Regional office will
be notified if chemical treatment other than COz sparging is planned for adjustment of high pH
water.
Appendix A
Site Map
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MAIN FLOOR ELEVATION (MFE)
BOTTOM OF EXCAVATION
FRONT GARAGE ELEVATION
417.10
413.60
416.67
CONSTRUCTION SEQUENCE NOTES
1. SCHEDULE A PRE -CON THROUGH MYBUILINGPERMIT.COM AND
EMAIL ENGINEERINGPERM ITS(aEDMONDSWA.GOV
2 DAYS IN ADVANCED OF DATE REQUESTED.
2. REVIEW TEMPORARY EROSION AND SEDIMENT CONTROL NOTES.
3. CALL FOR UTILITY LOCATES.
4. INSTALLTESC MEASURES AND MAINTAIN DUST CONTROL WHILE
PREVENTING DISTURBANCE OF ANY AREAS OF VEGETATION c
OUTSIDE THE CONSTRUCTION ZONE.
5. HAVE EROSION CONTROL MEASURES INSPECTED BY THE CITY OF
EDMONDS ENGINEERING INSPECTOR.ALLTEMPORARY
SEDIMENTATION AND EROSION CONTROL MEASURES MUST BE IN
PLACE AND INSPECTED PRIOR TO ANY CONSTRUCTION OR SITE
CLEARING. EROSION AND SEDIMENTATION CONTROL PREACTICES
AND/OR DEVICES SHALL BE MAINTAINED UNTIL PERMANENT
VEGETATION IS ESTABLISHED.
6. DEMOLISH EXISTING STRUCTURES.
7. ROUGH GRADE SITE AS REQUIRTED TO INSTALL DRAINAGE
FEATURES.
8. CLEAR, GRUB & ROUGH GRADE SITE. COMPOSTAMEND AND
REVEGETATE DISTURBED AREAS NOT SUBJECTTO ADDITIONAL
SURFACE DISTURBANCE IMMEDIATELY AFTER ROUGH GRADING,
OTHER EXPOSED AREAS SHALL BE STABILIZED PER EROSION
CONTROL NOTES BELOW.
9. INSTALL UTILITIES AND OTHER SITE IMPROVEMENTS, INCLUDING
FRONTAGE IMPROVEMENTS.
10. STABILIZE AND COMPOSTAMEND ALL EXPOSED SOILS PER CITY OF
EDMONDS STANDARD DETAIL SD-642 PRIOR TO REVEGETATION OF
ENTIRE SITE.
11. ESTABLISH LANDSCAPING AND PERMANENT VEGETATION. ALL
TEMPORARY EROSION CONTROL MEASURES SHALL BE REMOVED
UPON FINAL SITE STABLIZIATION AND APPROVAL BY THE CITY.
12. STABILIZE AND COMPOSTAMEND ALL EXPOSED SOILS PRIOR TO
REVEGETATIONOF ENTIRE SITE. REFER TO CITY STANDARD DETAIL
SD-642.
13. ESTABLISH LANDSCAPING AND PERMANENT VEGETATION. ALL
TEMPORARYEROSION CONTROL MEASURES SHALL BE REMOVED
UPON FINAL SITE STABILIZATION AND APPROVAL BY CITY
INSPECTOR.
NOTE: CONTRECTOR TO GRADE SITE TO
PROVIDE POSITIVE DRAINAGE AWAY FROM
STRUCTURE AROUND ENTIRE BUILDING
PERIMETER.
FLOW DISPERSION TRENCH
2' WIDE X 6" DEEP
10.81'.
EXISTING
DRIVWAY
DE AT PROPERTY CORNER
416.27
EXISTING DRIVEWAY
20.38' /
HOUSE HEIGHT CALCULATIONS
/
HOUSE RECTANGLE EXISITNG CORNER
ELEVATIONS
POI NT A
416.78
POINT B
416.40
POI NT C
415.23 -
POI NT D
415.99
AVERAGE EXISTING GRADE
416.10
MAXIMUM ROOF HEIGHT
441.10 -
VERTICAL FEET BETWEEN
MAX AND PROPOSED
000.34
HEIGHT SURVEY REQUIRED AS LESS THAN
1 FOOT DIFFERENCE
MAIN FLOOR ELEVATION
417.10
FRONT GARAGE ELEVATION
416.67
IMPERVIOUS CALCULATIONS
LOT AREA
=15,056 SF
HOUSE
= 2,974 SF
LOT COVERAGE
=19.8%
ROOF AREA
= 3,259 SF
DRIVEWAY/WALKWAY/PATIO
=1,827 SF
HOUSE
= 5,131 SF
IMPERVIOUS
= 34.1%
A PORTION OF THE NW 1/4, SECTION 19, TO
C D
O CRETE HEAT PAD FOR HEAT PUMP
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100LLF 6" PVC 8.30 ��
1 1
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CB#2 -TYPE 2 48" J
RIM 417.18
\ 6" PVC (E) 412.51
6" PVC (W) 412.51
-+ a
21' DRIVEWAY WITH WINGS NEW 6" PVC
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OHP OHP &P
SSMH RIM=416.53'
DRIVEWAY BMP T5.12 SHEET FLOW =1,516 SF
IE=407.18' (8" IN E)
DRIVEWAY LOCATED WITHIN ROW = 310 SF IE=407.08' (8" OUT W)
(TO BE DRAINED TOWARDYD#1)
REMAINING IMPERVIOUS FOR DETENTION =
3,615 SF
R-TANK VOLUME REQUIRED =
72.3 SF X 3DEPTH
=
216.9 C F
R-TANK DETENTION PROVIDED =
3.08 SF X 25 MODULES X 3DEPTH X 95 % POROSITY
=
219.3 CF
MAX. ALLOWED IMPERVIOUS =
5,166 SF
11
SANITARY SEWER
SERVICE AT 7.8% MIN
SLOPE
12" WATER BOTTOM OF PIPE 414.92
- 6" SEWER TOP OF PIPE=410.41
4.5T CLEARANCE BETWEEN PIPES
s
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APPROX INVERT=408.69 -
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- SD - - SD - SD SD - - SD
-OHP OHP OHP OHP OHP OHF --+OHP
PEDESTRAIN CROSSWALK'
ACROSS SCHOOL DRIVEWAY
CB T-1 RIM=417.00'
IE=411.48' (12" CONC E)
IE=411.48' (12" CONC W)
TYPEOFAREA
AREA(SF)
STORMWATERFACIL ITY
LAWN AND LANDSCAPE
9938
RTANKDETENTION
ROOFS
3259
R TANKDETENTION
DRIVEWAY
1516
BMPT5.12 SHEETFLOW
DRIVEWAY
293
R TANKDETENTION
%RETROFIT
3423
REMOVAL
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Pi27 NORTH, RANGE 4 EAST, W.M.
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\ 10 0 5 10 20
(FEET)
NOTE: R-TANK IS NOTTRAFFIC-BEARING
AND LANDSCAPING OR ROCK FEATURES
SHALL BE INSTALLED TO PREVENT
VEHICLES FROM DRIVING OVER THE TANK.
NOTE: CONTRACTOR SHAL POTHOLE TO
VERIFY EXISTING SEWER INVERT
ELEVATIONS FOR SANITARY SEWER AND
CONTACT ENGINEER IF ELEVATIOKNS
VARY FROM THIS SHOWN
A MINIMUM OF 3HORIZONTAL
SEPARATION
AND 1' VERTICAL SEPERATION IS
REQUIRED BETWEEN DRY UTILITIES AND
SEWER, WATER, STORM AND 5'
HORIZONTAL SEPERATION FROM ANY
CITY MAINLINES.
- FOOTING DRAIN CONNECTION
6" PVC I E 413.60 \
I \ �
\ I PROPOSED PRIVATE DRAINAGE
\\ i EASEMENT FXTENTS
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10.75'
DRAIN EASEMENT N89°04'20"E 78.39'
GRADE AT PROPERTY CORNER
417.68 �-
CB#1 -TYPE 2 48" WITH SOLIlD�ID-
RIM 417.86
6" PVC (N,W) 412.30
12"CPEP (S) 411.80
0
f- W - -W -
1� 0 200TH ST SW
uj a 12" STORM TOP OF PIPE 412.66
a 12" WATER BOTTOM OF PIPE 414.42
0 1.76" CLEARANCE BETWEEN PIPES PROVIDED
N
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SS SS SS SS SS
M
8" SANITARY SEWER PIPE 408.69
12" STORM BOTTOM OF PIPE 411.6
2.64' CLEARANCE BETWEEN PIPES PROVIDED
SD SD SD - SD - 3D -_�SQ SD -
G G G
OHP OHP OHP OHP
OHP OHP OHP -OHP-
CB T-1 RIM=418.14'
IE=411.62' (12" CONC E)
IE=411.62' (12" CONC W)
IE 411.62' (12" CPEP) NEW
DATUM NAVD 88
UTILITY KEYNOTES
OTHE ROOF DRAINS ARE TO BE CONNECTED TO THE R-TANK.
OTHE FOOTING DRAINS TO BE CONNECTED INTO CB#1.
G
DRIVEWAY TO BE SLOPED TOWARD SHEET FLOW DISPERSION TRENCH ON
WEST SIDE OF DRIVEWAY. SHEET FLOW DISPERSION TRENCH TO USE
DETAIL SD-635 ON SHEET C4.0. DRIVEWAY LOCATED WITHIN ROW TO BE
SLOPED TOWARDS YARD DRAIN #1 AT EDGE OF ROW. INSTALL SHALLOW
BERM ON WEST SIDE OF DRIVEWAY WITHIN ROW IF NECESSARYTO MAKE
STORMWATER FLOW TO YARD DRAIN #1.
O4 EX CHARGING STATION TO BE LOCATED WITHIN THE GARAGE.
OINSTALL R-TANK PER MANUFACTURER SHOP DRAWINGS ON PAGES C4.2
5 AND C4.3.
R-TANK HD
25 DOUBLE + MINI (2.5) MODULES
GRAVEL BASE FROM 412.26 TO 412.51
INSTALL R-TANK MODULES AT 412.51
TOP OF R-TANK 416.05
12" COVER ALLOWED WHERE ALL VEHICLE LOADING IS RESTRICTED
MINIMUM GRADE OVER TANK 417.05
(DNEW 1" METER TO BE INSTALLED BYTHE CITY OF EDMONDS PUBLIC
WORKS DEPARTMENT IN PROPOSED ROW PER WA-130.
OINSTALL NEW 1 )/2" POLY WATER LINE WITH TRACER WIRE. TO BE INSTALLED
BY CITY OF EDMONDS PUBLIC WORKS.
ORESTORE TRENCH PAVEMENT DEMOLITION AREA PER GU-410. SEE DETAIL
GU-400 ON SHEET C4.0. ALL PAINT/STRIPING PER CITY OF EDMONDS
PUBLIC WORKS STANDARDS TO MATCH ADJACENT PAVEMENT.
ORE -LAY SEWER AND INSTALL 4" SSCO WITHIN 2' OF HOUSE. APPROX I.E. _
411.86
10 INSTALL 6" SSCO ON NEW SEWER SERVICE AT EDGE OF ROW PER DETAIL
SS-200. APPROX I.E. = 410.87.
11 CB # 2 WITH ONE 0.5" DIAMETER ORIFICE. ORIFICE TO USE DETAIL SD-301
WITH OVERFOW AT 415.51.
INSTALL UNDERGROUND NEW DRY UTILITY. LINES FROM EXISTING POLE 3"
12 CON DUIT-PSE POWER. 1" CON DU ITCOMCAST.1" CONDUIT-ZIPLY. UTILITY
BORING BY SNOHOMISH COUNTY PUD #1.
13 CONNECT TO EXISTING CB. IE= 411.62
14 DRIVEWAY TO BE CONSTRUCTED OF 3" HMA CL 2" (OVER 6" CRUSHED
SURFACING) WITHIN ROW, AND 6" CONCRETE OVER 4" CRUSHED
SURFACING ON PRIVATE PROPERTY.
PROPOSED UTILITY LEGEND
- - - - - - - - - - - - - - - - FOUNDATION DRAIN
RD ROOF DRAIN
W W WATER SERVICE
UGP UNDERGROUND POWER SERVICE
WATER METER
CB T-1 RIM=419.51'
IE=412.46' (12" CONC E)
IE=412.46' (12" CONC W)
IE=412.56' (12" CONC N)
DATUM INFORMATION IS DERIVED FROM SSHM ON 200TH
STREET
ELEV = 416.53'
YD, CB TYPE 2
OSEWER CLEANOUT
NOTES:
1. REPLACE ALL DISTURBED HARD SURFACES NECESSARY
FOR SIDE SEWER CONSTRUCTION WITH LIKE MATERIAL
PER GU-410.
2. FINAL SURFACE RESTORATION WITHIN RIGHT-OF-WAY
TO BE COMPLETED BY CONTRACTOR NOT CITY OF
EDMONDS.
3. UTILITY PATCHES WITH LESS THAN 20 FEET OF
SEPARATION TO BE COMBINED AND FULL WIDTH OR
HALF WIDTH OVERLAY WILL BE REQUIRED DEPENDING
ON THE EXTENT OF DISTURBANCE. WHERE UTILITY
PATCHES FALL ENTIRELY WITHIN ONE TRAVEL LANE,
THE OVERLAY SHALL EXTEND TO THE CENTERLINE OF
THE ROADWAY. WHERE UTILITY PATCHES EXTEND INTO
BOTH TRAVEL LANES THEN A FULL WIDTH OVERLAY IS
REQUIRED.
4. EXISTING FAILING OR DAMAGED ROW IMPROVEMENTS
SHALL BE REMOVED AND REPLACED AS DETERMINED
BY THE CITY ENGINEERING INSPECTOR.
S. A MINIMUM OF 3HORIZONTAL SEPARATION AND 1'
VERTICAL SEPARATION IS REQUIRED BETWEEN DRY
UTILITIES AND SEWER, WATER, STORM AND 5 FROM
ANY CITY MAINLINES.
6. UTILITY CROSSINGS WITHIN THE ROW TO BE RESTORED
TO EXISTING CONDITIONS PER GU-400 AND GU-410.
7. 10' PROPOSED ROW SHOWN ONLY AS REFERENCE TO
CITY OF EDMONDS OFFICIAL STREET MAP. NO ROW IS
PROPOSED TO BE DEDICATED AS PART OF THIS PERMIT.
8. MATAIN A MINIMUM OF 3OF HORIZONATAL
SEPERATION BETWEEN THE WATER SERVICE AND DRY
UTILITIES.
APPROVED FOR CONSTRUCTION
CITY OF EDMONDS
DATE:
BY:
CITY ENGINEERING DIVISON
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MOMENTUM CIVIL
1145 BROADWAY, SUITE 115
TACOMA, WA 98402
PHONE: 253.319.1504
CHECKED BY: D. HARRIS
DESIGNED BY: D.HARRIS
DRAWN BY: J.SANTOS
HORZ. DATUM:NAV83/91
VERT. DATUM: NAVD88
DATE: 07/16/24
PROJECT NO. VILL-001
SHEET NO. 2 OF 9
REFERENCE NO. C2.0
Appendix B
BMP Detail
Maintenance Standards
If the fence has been damaged or visibility reduced, it shall be repaired or replaced immediately and
visibility restored.
BMP C105: Stabilized Construction Access
Purpose
Stabilized construction accesses are established to reduce the amount of sediment transported onto
paved roads outside the project site by vehicles or equipment. This is done by constructing a sta-
bilized pad of quarry spalls at entrances and exits for project sites.
Conditions of Use
Construction accesses shall be stabilized wherever traffic will be entering or leaving a construction
site if paved roads or other paved areas are within 1,000 feet of the site.
For residential subdivision construction sites, provide a stabilized construction access for each res-
idence, rather than only at the main subdivision entrance. Stabilized surfaces shall be of sufficient
length/width to provide vehicle access/parking, based on lot size and configuration.
On large commercial, highway, and road projects, the designer should include enough extra mater-
ials in the contract to allow for additional stabilized accesses not shown in the initial Construction
SWPPP. It is difficult to determine exactly where access to these projects will take place; additional
materials will enable the contractor to install them where needed.
Design and Installation Specifications
See Figure II-3.1: Stabilized Construction Access for details. Note: the 1 00'minimum length of the
access shall be reduced to the maximum practicable size when the size or configuration of the site
does not allow the full length (100').
Construct stabilized construction accesses with a 12-inch thick pad of 4-inch to 8-inch quarry spalls,
a 4-inch course of asphalt treated base (ATB), or use existing pavement. Do not use crushed con-
crete, cement, or calcium chloride for construction access stabilization because these products raise
pH levels in stormwater and concrete discharge to waters of the State is prohibited.
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 standards listed in Table 11-3.2: Stabilized Con-
struction Access Geotextile Standards.
Table 11-3.2: Stabilized Construction Access
Geotextile Standards
Geotextile Property I Required Value
Grab Tensile Strength (ASTM D4751) 1 200 psi min.
2019 Stormwater Management Manual for Western Washington
Volume 11 - Chapter 3 - Page 275
BMP C240: Sediment Trap
Purpose
A sediment trap is a small temporary ponding area with a gravel outlet used to collect and store sed-
iment from sites during construction. Sediment traps, along with other perimeter controls, shall be
installed before any land disturbance takes place in the drainage area.
Conditions of Use
Sediment traps are intended for use on sites where the tributary drainage area is less than 3
acres, with no unusual drainage features, and a projected build -out time of six months or less.
The sediment trap is a temporary measure (with a design life of approximately 6 months) and
shall be maintained until the tributary area is permanently protected against erosion by veget-
ation and/or structures.
Sediment traps are only effective in removing sediment down to about the medium silt size
fraction. Runoff with sediment of finer grades (fine silt and clay) will pass through untreated,
emphasizing the need to control erosion to the maximum extent first.
Projects that are constructing permanent Flow Control BMPs, or Runoff Treatment BMPs
that use ponding for treatment, may use the rough -graded or final -graded permanent BMP
footprint for the temporary sediment trap. When permanent BMP footprints are used as tem-
porary sediment traps, the surface area requirement of the sediment trap must be met. If the
surface area requirement of the sediment trap is larger than the surface area of the per-
manent BMP, then the sediment trap shall be enlarged beyond the permanent BMP footprint
to comply with the surface area requirement.
2019 Stormwater Management Manual for Western Washington
Volume 11 - Chapter 3 - Page 383
. A floating pond skimmer maybe used for the sediment trap outlet if approved by the Local Per-
mitting Authority.
Sediment traps may not be feasible on utility projects due to the limited work space or the
short-term nature of the work. Portable tanks may be used in place of sediment traps for utility
projects.
Design and Installation Specifications
• See Figure II-3.26: Cross Section of Sediment Trap and Figure II-3.27: Sediment Trap Outlet
for details.
. To determine the sediment trap geometry, first calculate the design surface area (SA) of the
trap, measured at the invert of the weir. Use the following equation:
SA = FS(Q2/Vs)
where
Q2 =
o Option 1 - Single Event Hydrograph Method:
Q2 = Peak volumetric flow rate calculated using a 10-minute time step from a Type 1A,
2-year, 24-hour frequency storm for the developed condition. The 10-year peak volu-
metric flow rate shall be used if the project size, expected timing and duration of con-
struction, or downstream conditions warrant a higher level of protection.
o Option 2 - For construction sites that are less than 1 acre, the Rational Method may be
used to determine Q2.
Vs = The settling velocity of the soil particle of interest. The 0.02 mm (medium silt) particle with
an assumed density of 2.65 g/cm3 has been selected as the particle of interest and has a set-
tling velocity (Vs) of 0.00096 ft/sec.
FS = A safety factor of 2 to account for non -ideal settling.
Therefore, the equation for computing sediment trap surface area becomes:
SA = 2 x Q2/0.00096
or
2080 square feet per cfs of inflow
Sediment trap depth shall be 3.5 feet minimum from the bottom of the trap to the top of the
overflow weir.
. To aid in determining sediment depth, all sediment traps shall have a staff gauge with a prom-
inent mark 1-foot above the bottom of the trap.
2019 Stormwater Management Manual for Western Washington
Volume 11 - Chapter 3 - Page 384
Design the discharge from the sediment trap by using the guidance for discharge from tem-
porary sediment ponds in BMP C241: Sediment Pond (Temporary).
Maintenance Standards
Sediment shall be removed from the trap when it reaches 1-foot in depth.
. Any damage to the trap embankments or slopes shall be repaired.
2019 Stormwater Management Manual for Western Washington
Volume 11 - Chapter 3 - Page 385
Figure II-3.26: Cross Section of Sediment Trap
Surface area determined
at top of weir
1' Min.
3.5' - 5'
1.5' Min.
Flat Bottom
Note: Trap may be formed by berm or by
partial or complete excavation.
DEPARTMENT OF
ECOLOGY
State of Washington
%4" - 1.5"
Washed gravel
Geotextile
2" - 4" Rock
Rip Rap
Discharge to
stabilized
conveyance,
outlet, or level
spreader
NOT TO SCALE
Cross Section of Sediment Trap
Revised June 2016
Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions,
limitation of liability, and disclaimer.
2019 Stormwater Management Manual for Western Washington
Volume 11 - Chapter 3 - Page 386
Figure 11-3.27: Sediment Trap Outlet
Native soil or
compacted backfill
DEPARTMENT OF
ECOLOGY
State of Washington
6' Min.
'I'Min. depth overflow spillway
Geotextile
Min. 1' depth 2" - 4" rock
Min. 1' depth %4" - 1.5"
washed gravel
Sediment Trap Outlet
NOT TO SCALE
Revised June 2016
Please see http://www.ecy.wa.gov/cop3aVht.html for copyright notice including permissions,
limitation of liability, and disclaimer.
2019 Stormwater Management Manual for Western Washington
Volume /I - Chapter 3 - Page 387
BMP T5.12: Sheet Flow Dispersion
Purpose and Definition
Sheet flow dispersion is the simplest method of runoff control. This BMP can be used for any imper-
vious or pervious surface that is graded to avoid concentrating flows. Because flows are already dis-
persed as they leave the surface, they need only traverse a narrow band of adjacent vegetation for
effective on -site stormwater management.
Applications and Limitations
Use this BMP for flat or moderately sloping (< 15% slope) surfaces such as driveways, sports courts,
patios, roofs without gutters, lawns, pastures; or any situation where concentration of flows can be
avoided.
Design Guidelines
. See Figure V-3.2: Sheet Flow Dispersion for Driveways for details for driveways.
. See BMP T5.10B: Downspout Dispersion Systems for dispersion trench design criteria.
• Provide a 2-foot-wide transition zone to discourage channeling between the edge of the imper-
vious surface (or building eaves) and the downslope vegetation. This transition zone may con-
sist of an extension of subgrade material (crushed rock), modular pavement, drain rock, or
other material acceptable to the Local Plan Approval Authority.
• Provide a 10-foot-wide vegetated buffer for up to 20 feet of width of paved or impervious sur-
face. Provide an additional 10 feet of vegetated buffer width for each additional 20 feet of
impervious surface width or fraction thereof. For example, if a driveway is 30 feet wide and 60
feet long provide a 20-foot wide by 60-foot long vegetated buffer, with a 2-foot by 60-foot trans-
ition zone.
. The design must not result in erosion or flooding of downstream properties.
• Runoff discharge toward landslide hazard areas must be evaluated by a geotechnical engin-
eer or a qualified geologist. Do not allow sheet flow on or above slopes greater than 20%, or
above erosion hazard areas, without evaluation by a geotechnical engineer or qualified geo-
logist and approval by the Local Plan Approval Authority.
• For sites with septic systems, the discharge area must be ten feet downgradient of the drain -
field primary and reserve areas (WAC 246-272A-0210). A Local Plan Approval Authority may
waive this requirement if site topography clearly prohibits flows from intersecting the drain -
field.
Runoff Model Representation
Where this BMP is used to disperse impervious area runoff into an undisturbed native landscape
area or an area that meets BMP T5.13: Post -Construction Soil Quality and Depth, the impervious
area should be modeled as a lateral flow impervious area. Do this in WWHM on the Mitigated
2019 Stormwater Management Manual for Western Washington
Volume V - Chapter 3 - Page 692
Scenario screen by connecting the lateral flow impervious area element (representing the area that
is dispersed) to the lawn/landscape lateral flow soil basin element (representing the area that will be
used for dispersion).
2019 Stormwater Management Manual for Western Washington
Volume V - Chapter 3 - Page 693
Figure V-3.2: Sheet Flow Dispersion for Driveways
Source: King County Department
of Natural Resources, 1998
2.4"
�6'min�
Berm Detail
O [n p MI
Locate drain 25' from °
ROW if driveway
slopes toward street.
sq. ft. max. between berm)
Driveway _
Slope
I s" Diagonal
25' vegetated berm with 25'
flowpath dispersion
/ trench / I
Plan
Driveway Dispersion Trench
Driveway Slope Varies and Slopes Toward Street
0
Max. 2 /o Driveway I
cross slope p SI�
/
Plan �--
,i sefd - ___
ab4--J a6
Sheet Flow Dispersion from a Driveways^
Flat to Moderately Sloping Driveways
DEPARTMENT OF
ECOLOGY
State of Washington
in
NOT TO SCALE
Sheet Flow Dispersion for Driveways
Revised December 2016
Please see http://www.ecy.wa.gov/copyright.html for copyright notice including permissions,
limitation of liability, and disclaimer.
2019 Stormwater Management Manual for Western Washington
Volume V - Chapter 3 - Page 694
Project Description
Re Name ...................................................... Sediment Trap
Project Options
RowUnits .....................................................
CFS
BevationType...............................................
Bevation
Hydrology Method .........................................
Santa Barbara UH
Time of Concentration (70C) Method ..............
SCST,55
Link Resting Method ......................................
Nnematic Wave
Enable Overflow FbndingatNodes .................
YES
Skip SteadyStateAnalysis TiimePeriods .........
NO
Analysis Options
Start Analysis On ...........................................
00:00:00
1:00:00
End Analysis On .............................................
00:00:00
1:00:00
Start RaportingOn.........................................
00:00:00
1:00:00
Antecedent Dry Days ......................................
0
days
Ranoff(Dry Weather) TimeStep ......................001:00:00
dayshh:mm:ss
Ranoff(WetWeather) TiimeStep .....................000:05:00
dayshh:mm:ss
R ortingTimeStep.......................................000:05:00
dayshh:mm:ss
fbutingTiimeStep ..........................................30
seconds
Number of 6ements
Qty
FainGages ....................................................
1
Subbasi ns......................................................
1
Nodes............................................................
1
Unctions................................................
0
Outfalls..................................................
1
flow Divarsl ons......................................
0
Inlets......................................................
0
Storage Nodes ........................................
0
Links..............................................................
0
Channels................................................
0
Rpes......................................................
0
PUMPSps....................................................
0
Orifices...................................................
0
VWrs......................................................
0
Outlets...................................................
0
Fbl I utants......................................................
0
LandUses .....................................................
0
Rainfall Details
SN Rain Gage Data Data Source Fainfall Fain State County Raturn Rainfall
ID Source ID Type Units Period Depth
Subbasin Summary
SN Subbasin Area Impervious
Impervious Pervious
Total
Total
Total Peak
Time of
ID Area
Area Curve Area Curve
Rainfall
Runoff
Runoff Runoff
Concentration
Number Number
Volume
(ac) (%)
(in)
(in)
(ac-in) (cfs)
(days hh:mm:ss)
1 Sub-01 0.35 35.00
98.00 81.00
1.55
0.68
0.24 0.05
0 00:06:00
Q2 for sediment trap
sizing
Node Summary
SN Element Element
Invert
Ground/Rim
Initial
Surcharge
Ponded Peak Max HGL
Max
Min Time of
Total Total Time
ID Type
Elevation
(Max)
Water
Elevation
Area Inflow Elevation
Surcharge
Freeboard Peak
Flooded Flooded
Elevation
Elevation
Attained
Depth
Attained Flooding
Volume
Attained
Occurrence
(ft)
(ft)
(ft)
(ft)
(ft) (cfs) (ft)
(ft)
(ft) (days hh:mm)
(ac-in) (min)
1 Out-01 Outfall
0.00
0.00 0.00
Subbasin Hydrology
Subbasin: Sub-01
Input Data
Area(ac).................................................................................
0.35
Impervious Area (%)...............................................................
35
Impervious Area Curve Number .............................................
98
Pervious Area Curve Number .................................................
81
Rain Gage ID..........................................................................
Rain Gage-01
Composite Curve Number
32
Area Soil Curve
Soil/Surface Description
(acres) Group Number
Composite Area & Weighted CN
0.35 86.95
Time of Concentration
TOC Method: SCS TR-55
Sheet Flow Equation :
To = (0.007 * ((n * Lf)^0.8)) / ((P^0.5) * (Sf^0.4
Where:
To = Time of Concentration (hr)
n = Manning's roughness
Lf = Flow Length (ft)
P = 2 yr, 24 hr Rainfall (inches)
Sf = Slope (ft/ft)
Shallow Concentrated Flow Equation
V = 16.1345 * (SfA0.5) (unpaved surface)
V = 20.3282*(SfA0.5)(paved surface)
V = 15.0 * (SfA0.5) (grassed waterway surface)
V = 10.0 * (SfA0.5) (nearly bare & untilled surface)
V = 9.0 * (SfA0.5) (cultivated straight rows surface)
V = 7.0 * (SfA0.5) (short grass pasture surface)
V = 5.0 * (SfA0.5) (woodland surface)
V = 2.5 * (SfA0.5) (forest w/heavy litter surface)
To = (Lf / V) / (3600 sec/hr)
Where
To = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (fUft)
Channel Flow Equation
V = (1.49 * (RA(2/3)) * (SfA0.5)) / n
R =Aq/Wp
To = (Lf / V) / (3600 sec/hr)
Where :
To = Time of Concentration (hr)
Lf = Flow Length (ft)
R = Hydraulic Radius (ft)
Aq = Flow Area (ft')
Wp = Wetted Perimeter (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
n = Manning's roughness
User -Defined TOC override (minutes): 6
Subbasin Runoff Results
Total Rainfall (in)..................................................................... 1.55
Total Runoff (in)...................................................................... 0.68
Peak Runoff (cfs).................................................................... 0.05
Weighted Curve Number........................................................ 86.95
Time of Concentration (days hh:mm:ss) ............................ 0 00:06:00
Subbasin : Sub-01
Rainfall Intensity Graph
0.38
0.36
0.34
0.32
0.3
0.28
0.26
0.24
0.22
0.2
0.18
0.16
0.14
0.12
0.1
0.08 Iry
0.06
0.04
0.02
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hrs)
Runoff Hydrograph
0.054
0.052
0.05
0.048
0.046
0.044
0.042
0.04
0.038
0.036
0.034
0.032
0.03
0.028
0.026
0.024
0.022
0.02
0.018
0.016
0.014
0.012
0.01
0.008
0.006
0.004
0.002
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hrs)
Appendix C
Correspondence
(To be added as needed)
Appendix D
Site Inspection Form
Construction Stormwater Site Inspection Form
Project Name
Permit #
Inspection Date
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
Concrete pours
Offsite improvements
C. Questions:
Time
Clearing/Demo/Grading Infrastructure/storm/roads
Vertical Utilities
Construction/buildings
Site temporary stabilized Final stabilization
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
Page 1
Construction Stormwater Site Inspection Form
D. Check the observed status of all items. Provide "Action Required "details and dates.
Element #
Inspection
BMPs
BMP needs
BMP
Action
Inspected
maintenance
failed
required
(describe in
yes
no
n/a
section F)
1
Before beginning land disturbing
Clearing
activities are all clearing limits,
Limits
natural resource areas (streams,
wetlands, buffers, trees) protected
with barriers or similar BMPs? (high
visibility recommended)
2
Construction access is stabilized
Construction
with quarry spalls or equivalent
Access
BMP to prevent sediment from
being tracked onto roads?
Sediment tracked onto the road
way was cleaned thoroughly at the
end of the day or more frequent as
necessary.
3
Are flow control measures installed
Control Flow
to control stormwater volumes and
Rates
velocity during construction and do
they protect downstream
properties and waterways from
erosion?
If permanent infiltration ponds are
used for flow control during
construction, are they protected
from siltation?
4
All perimeter sediment controls
Sediment
(e.g. silt fence, wattles, compost
Controls
socks, berms, etc.) installed, and
maintained in accordance with the
Stormwater Pollution Prevention
Plan (SWPPP).
Sediment control BMPs (sediment
ponds, traps, filters etc.) have been
constructed and functional as the
first step of grading.
Stormwater runoff from disturbed
areas is directed to sediment
removal BMP.
5
Have exposed un-worked soils
Stabilize
been stabilized with effective BMP
Soils
to prevent erosion and sediment
deposition?
Page 2
Construction Stormwater Site Inspection Form
Element #
Inspection
BMPs
BMP needs
BMP
Action
Inspected
maintenance
failed
required
yes
no
n/a
(describe in
section F)
5
Are stockpiles stabilized from erosion,
Stabilize Soils
protected with sediment trapping
Cont.
measures and located away from drain
inlet, waterways, and drainage
channels?
Have soils been stabilized at the end of
the shift, before a holiday or weekend
if needed based on the weather
forecast?
Has stormwater and ground water
6
been diverted away from slopes and
Protect
disturbed areas with interceptor dikes,
Slopes
pipes and or swales?
Is off -site storm water managed
separately from stormwater generated
on the site?
Is excavated material placed on uphill
side of trenches consistent with safety
and space considerations?
Have check dams been placed at
regular intervals within constructed
channels that are cut down a slope?
7
Storm drain inlets made operable
Drain Inlets
during construction are protected.
Are existing storm drains within the
influence of the project protected?
8
Have all on -site conveyance channels
Stabilize
been designed, constructed and
Channel and
stabilized to prevent erosion from
Outlets
expected peak flows?
Is stabilization, including armoring
material, adequate to prevent erosion
of outlets, adjacent stream banks,
slopes and downstream conveyance
systems?
9
Are waste materials and demolition
Control
debris handled and disposed of to
Pollutants
prevent contamination of stormwater?
Has cover been provided for all
chemicals, liquid products, petroleum
products, and other material?
Has secondary containment been
provided capable of containing 110%
of the volume?
Were contaminated surfaces cleaned
immediately after a spill incident?
Were BMPs used to prevent
contamination of stormwater by a pH
modifying sources?
Page 3
Construction Stormwater Site Inspection Form
Element #
Inspection
BMPs
BMP needs
BMP
Action
Inspected
maintenance
failed
required
(describe in
yes
no
n/a
section F)
9
Wheel wash wastewater is handled
Cont.
and disposed of properly.
10
Concrete washout in designated areas.
Control
No washout or excess concrete on the
Dewatering
ground.
Dewatering has been done to an
approved source and in compliance
with the SWPPP.
Were there any clean non turbid
dewatering discharges?
11
Are all temporary and permanent
Maintain
erosion and sediment control BMPs
BMP
maintained to perform as intended?
12
Has the project been phased to the
Manage the
maximum degree practicable?
Project
Has regular inspection, monitoring and
maintenance been performed as
required by the permit?
Has the SWPPP been updated,
implemented and records maintained?
13
Is all Bioretention and Rain Garden
Protect LID
Facilities protected from
sedimentation with appropriate BMPs?
Is the Bioretention and Rain Garden
protected against over compaction of
construction equipment and foot
traffic to retain its infiltration
capabilities?
Permeable pavements are clean and
free of sediment and sediment laden -
water runoff. Muddy construction
equipment has not been on the base
material or pavement.
Have soiled permeable pavements
been cleaned of sediments and pass
infiltration test as required by
stormwater manual methodology?
Heavy equipment has been kept off
existing soils under LID facilities to
retain infiltration rate.
E. Check all areas that have been inspected. ✓
All in place BMPs ❑ All disturbed soils ❑ All concrete wash out area ❑ All material storage areas
All discharge locations ❑ All equipment storage areas ❑ All construction entrances/exits ❑
Page 4
Construction Stormwater Site Inspection Form
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 5
Appendix E
Construction Stormwater General Permit (CSWGP)
(to be added once it is obtained)
Appendix F
303(d) List Waterbodies / TMDL Waterbodies Information
(no 303d or TMDL waterbodies for this project)
Appendix G
Contaminated Site Information
(no contaminates onsite)
Appendix H
Engineering Calculations
(not applicable)