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Civil Engineers ● Structural Engineers ● Landscape Architects ● Community Planners ● Land Surveyors
ESC Plan for
Construction Stormwater
Pollution Prevention
PREPARED FOR:
HHJ Architects, PLLC
601 Saint Helens Avenue
Tacoma, WA 98402
Contact: Chee Tung
PROJECT:
Walker Auto Dealership
3400 East Valley Road
Renton, WA 98057
2180100.10
PREPARED BY:
Matt Whittlesey, EIT
Project Engineer
REVIEWED BY:
Scott T. Kaul, PE, LEED AP
Project Manager
J. Matthew Weber, PE
Principal
DATE:
August 2018
Revised September 2018
ESC Plan for
Construction Stormwater
Pollution Prevention
PREPARED FOR:
HHJ Architects, PLLC
601 Saint Helens Avenue
Tacoma, WA 98402
Contact: Chee Tung
PROJECT:
Walker Auto Dealership
3400 East Valley Road
Renton, WA 98057
2180100.10
PREPARED BY:
Matt Whittlesey, EIT
Project Engineer
REVIEWED BY:
Scott T. Kaul, PE, LEED AP
Project Manager
J. Matthew Weber, PE
Principal
DATE:
August 2018
Revise September 2018
I hereby state that this ESC Plan for
Construction Stormwater Pollution
Prevention for the Walker Auto
Dealership project has been prepared by
me or under my supervision, and meets
the standard of care and expertise that is
usual and customary in this community
for professional engineers. I understand
that City of Renton does not and will not
assume liability for the sufficiency,
suitability, or performance of drainage
facilities prepared by me.
ESC Plan for Construction Stormwater Pollution Prevention
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2180100.10
Table of Contents
Section Page
1.0 Purpose ........................................................................................................................................... 1
2.0 Conditions of Use .......................................................................................................................... 2
3.0 Existing Site Conditions ................................................................................................................ 2
3.1 Existing Cover ..................................................................................................................... 2
3.2 Topography and Design ...................................................................................................... 2
3.3 Adjacent Areas .................................................................................................................... 2
4.0 ESC Plan Analysis and Design (Part A) ....................................................................................... 3
4.1 ESC Measures .................................................................................................................... 3
4.1.1 Clearing Limits ....................................................................................................... 3
4.1.2 Cover Measures ..................................................................................................... 3
4.1.3 Perimeter Protection .............................................................................................. 4
4.1.4 Traffic Area Stabilization ........................................................................................ 4
4.1.5 Sediment Retention ............................................................................................... 4
4.1.6 Surface Water Collection ....................................................................................... 4
4.1.7 Dewatering Control ................................................................................................ 4
4.1.8 Dust Control ........................................................................................................... 5
4.1.9 Flow Control ........................................................................................................... 5
4.1.10 Control Pollutants ................................................................................................... 5
4.1.11 Protect Existing and Proposed Flow Control BMPs ............................................... 5
4.1.12 Maintain BMPs ....................................................................................................... 5
4.1.13 Manage the Project ................................................................................................ 5
4.2 Erosion Problem Areas ....................................................................................................... 6
5.0 Stormwater Pollution Prevention and Spill (SWPPS) Plan Design (Part B) ............................. 6
5.1 Pollution and Spill Prevention Source Controls and BMPs ................................................. 6
5.2 Responsible Personnel and Contact Information ............................................................... 7
5.3 Pollution and Spill Prevention Worksheets ......................................................................... 7
5.4 Disposal Methods ................................................................................................................ 7
6.0 ESC Performance and Compliance Provisions .......................................................................... 7
6.1 ESC Supervisor ................................................................................................................... 7
6.2 Monitoring of Discharges .................................................................................................... 8
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6.3 ESC Performance ............................................................................................................... 8
6.4 Flexible Compliance ............................................................................................................ 8
6.5 Roads and Utilities Compliance .......................................................................................... 8
6.6 Alternative and Experimental Measures ............................................................................. 8
7.0 ESC Implementation Requirements ............................................................................................. 8
7.1 Wet Season Requirements ................................................................................................. 8
7.2 Critical Areas Restriction ..................................................................................................... 9
7.3 Maintenance Requirement .................................................................................................. 9
7.4 Construction Sequence ..................................................................................................... 10
7.5 Final Stabilization .............................................................................................................. 11
7.6 NPDES Requirements ...................................................................................................... 11
7.7 Forest Practice Permit Requirements ............................................................................... 11
8.0 Construction Schedule ................................................................................................................ 11
ESC Plan for Construction Stormwater Pollution Prevention
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Appendices
Appendix A
Exhibits
A-1 ............. Vicinity Map
A-2 ............. Existing Conditions Map
C0.1 ........... Cover Sheet (Early Grading Permit)
C0.2 ........... Existing Conditions (Topographic Survey)
C0.3 ........... Test Pit and Excavation Map / Phasing Plan
C1.1 ........... Demo, Excavation, and Clean-Up Plan
C2.1 ........... Rough Grading and TESC Plan
C3.1 ........... TESC Notes and Details
C3.2 ........... TESC Notes an Details
Appendix B
Select King County Source Control BMPs
Appendix C
Inspection and Maintenance Report Forms
Appendix D
Geotechnical Report
Migizi Group, Inc., April 27, 2018
Appendix E
Sediment Pond Sizing
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1.0 Purpose
In 1972, Congress passed the Federal Water Pollution Control Act (FWPCA), also known as the
Clean Water Act (CWA), to restore and maintain the quality of the nation's waterways. The
ultimate goal was to ensure that rivers and streams were fishable, swimmable, and drinkable. In
1987, the Water Quality Act (WQA) added provisions t o the CWA that allowed the Environmental
Protection Agency (EPA) to govern stormwater discharges from construction sites. In 1998, the
EPA published the final notice for General Permits for Storm Water Discharges from Construction
Activities Disturbing 5 Acres or Greater (63 Federal Register 7898, February 14, 1998). The
general permit includes provisions for development of a Stormwater Pollution Prevention Plan
(SWPPP) to maximize the potential benefits of pollution prevention, and sediment and erosion
control measures at construction sites.
Development, implementation, and maintenance of the Construction SWPPP will provide the
selected General Contractor with the framework for reducing soil erosion and minimizing
pollutants in stormwater during construct ion. The Construction SWPPP will:
Define the characteristics of the site and the type of construction that will occur.
Describe the practices that will be implemented to control erosion, and the release of
pollutants in stormwater.
Create an implementation schedule to ensure that the practices described in this
Construction SWPPP are in fact implemented; and to evaluate the plan's effectiveness in
reducing erosion, sediment, and pollutant levels in stormwater discharged from the site.
Describe the final stabilization/termination design to minimize erosion and prevent
stormwater impacts after construction is complete.
This Construction SWPPP includes the following:
Identification of the Construction SWPPP Coordinator with a description of this person's
duties.
Identification of the Stormwater Pollution Prevention Team (SWPP Team) that will assist in
implementation of the Construction SWPPP during construction.
Description of the existing site conditions, including existing land use for the site, soil types
at the site, as well as the location of surface waters that are located on or next to the site.
Identification of the body or bodies of water that will receive runoff from the construction
site, including the ultimate body of water that receives the stormwater.
Identification of drainage areas and potential stormwater contaminants.
Description of stormwater management controls and various Best Management Practices
(BMPs) necessary to reduce erosion, sediment, and pollutants in stormwater discharge.
Description of the facility monitoring plan, and how controls will be coordinated with
construction activities.
Description of the implementation schedule and provisions for amendment of the plan.
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2.0 Conditions of Use
This report accompanies the early clear and grade plans and documents for the Walker Auto
Dealership project located at 3400 East Valley Road in the city of Renton. The site is located on
Parcel No. 3023059067. The future project proposes an approximately 48,000-square foot auto
dealership, with associated parking and drive aisles. The project site is approximately 5.65 acres
in size.
Due to the existence of onsite contaminated soils and previous development of a wetland buffer
this early scope of work is proposed to remove contamination from the site below state allowable
levels, restore and plant the wetland buffer to 75.0’, and grade and stabilize the site. The primary
goal of this work is to enter the voluntary clean-up program with ecology and receive a No Further
Action letter.
Stormwater management is to comply with the 2016 King County Surface Water Design Manual
(KCSWDM), as amended by the City of Renton, the 2016 City of Renton Surface Water Design
Manual (CRSWDM).
3.0 Existing Site Conditions
3.1 Existing Cover
The site sits on a 5.65-acre parcel near the intersection of East Valley Road and SW 34th Street.
The site is bordered to the west by East Valley Road, to the south by an industrial vehicle storage
area, to the east by SR 167, and to the north by an RV storage lot.
The site is currently vacant, and was previously an auto wrecking yard. The site contains an
asphalt driveway and parking area and an existing office building. The remaining portion of the
site is a gravel storage area. Remaining contamination from the previous use as an auto
wrecking yard will be remediated through Ecology’s Voluntary Cleanup Program. Cleanup of the
site will occur during the early clear and grade activities.
There is a wetland located directly east of the site. A Critical Areas Report by PBS dated April
2018 classifies the wetland as Category III. The wetland is located mostly within Washington
State Department of Transportation (WSDOT) right-of-way. The proposed onsite wetland buffer is
75 feet. Restoration of the wetland buffer will be part of the early clear and grade work.
Restoration of the offsite wetland will be completed under the direction of WSDOT.
3.2 Topography and Design
The site is relatively flat. Runoff from the existing site either drains to the depression in the
southwest corner of the site that was previously pumped to East Valley Road or drains to the
wetland offsite in WSDOT ROW.
This early grading plan will generally match the two existing basins onsite.
3.3 Adjacent Areas
The site is bordered to the west by East Valley Road, to the south by an industrial vehicle storage
area, to the east by SR 167, and to the north by an RV storage lot.
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4.0 ESC Plan Analysis and Design (Part A)
4.1 ESC Measures
The purpose of this section is to describe how each of the 13 erosion and sediment control (ESC)
measures has been addressed and to identify the type and location of BMPs used to satisfy the
required measure.
4.1.1 Clearing Limits
Clearing limits are identified on the plans. Prior to beginning land disturbing activities, clearing
limits will be marked with flagging (BMP D.2.1.1) or high visibility plastic or metal fence
(BMP D.2.1.1.1).
4.1.2 Cover Measures
Because source control is the most important form of erosion control, construction practices must
adhere to strict cover requirements. Exposed and unworked soils shall be stabilized with the
application of effective BMPs to prevent erosion throughout the life of the project. The specific
BMPs for soil stabilization that shall be used on this project include:
Mulching (BMP D.2.1.2.2)
Plastic Covering (BMP D.2.1.2.4)
Temporary and Permanent Seeding (BMP D.2.1.2.6)
More specifically, during the period of May 1 through September 30, the Contractor will not be
allowed to leave soils unprotected for more than seven days, and immediate seeding will be
required for areas brought to finish grade with no further work planned for the next 30 days.
Areas to be paved may be armored with crushed rock subbase in place of other stabilizing
measures. The area of clearing will be limited to the amount that can be stabilized by
September 30 of that year.
During the period of October 1 through April 30, all disturbed soil areas will be covered or
stabilized within two days or 24 hours when a major storm even is predicted. Cover measures
may include mulching, netting, plastic sheeting, erosio n control blankets, or free draining material.
The extent of clearing shall be limited to the amount of land that can be covered or stabilized
within 24 hours.
Soil stockpiles shall be stabilized by plastic covering or surrounded by filter fabric fence.
The Contractor has the option of providing all required material for cover measures onsite at all
times, or preparing a plan of action to submit to the City of Renton. A plan of action shall contain
the following:
Contractor’s name, address, phone number, and emergency phone number.
Alternate contact with above information.
Clearly defined plan of action designed to prevent offsite migration of sediments, which will
be implemented in the event that a major storm is predicted or offsite erosion is observed
by the Contractor, his/her employees, or the City.
Description of materials to be used for cover and means by which it will be placed. List
equipment to be used or number of personnel anticipated to be used to spread material.
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Vendor or supplier of materials used; list two alternates and include phone numbers.
Means and timeframe for cleanup of any materials that escape offsite and for repairs to the
natural system if damages have occurred.
In order for the ESC facilities to function properly, they m ust be maintained and sediment
removed on a regular basis. Inspection and sediment removal shall be performed on all ESC
facilities, as described in the inspection schedule located in Section 7.3 of this report.
4.1.3 Perimeter Protection
Perimeter protection to filter sediment from sheet wash shall be located downslope of all
disturbed areas and shall be installed prior to upslope grading. Filter fabric fencing (BMP
D.2.1.3.1) will be required around the south, north, east, and west edges of the site and around
stockpile areas to prevent sediment-laden stormwater from being transported offsite. During the
wet season, 50 linear feet of filter fabric fencing per acre will be required.
4.1.4 Traffic Area Stabilization
A stabilized construction entrance shall be insta lled as the first step of clearing and grading. The
stabilized construction entrance (BMP D.2.1.4.1) will be used to prevent the transport of sediment
onto the adjacent paved surfaces. If sediment is transported onto the road surface, the road shall
be cleaned each day by sweeping or vacuuming prior to washing. Sediment removal by washing
alone will not be allowed. If sediment is tracked from the site, the City may require stabilization of
internal roads and car parking areas to contain the sediment (BMP D.2.1.4.2) or require the
installation of a wheel wash basin (BMP D.2.1.4.3).
4.1.5 Sediment Retention
The first priority is to keep all access roads clean of sediment and keep street wash water
separate from entering storm drains until treatment can be provided. Storm drain inlet protection
(BMP D.3.5.3) will be implemented for all drainage inlets and culverts that could potentially be
impacted by sediment-laden runoff on and near the project site, including offsite catch basins
located downstream of the project site. Storm drain inlet sediment protection will prevent coarse
sediment from entering the drainage system prior to permanent stabilization of the disturbed
areas.
4.1.6 Surface Water Collection
Interceptor swales or dikes (BMP D.2.1.6.1) will be installed at the top of all slopes in excess of
3H:1V and greater than 20 feet of elevation change.
Outlet protection (BMP D.2.1.6.5) is required at the outlets of all ponds, pipes, ditches, or other
approved conveyances, and where runoff is conveyed to natural or m anmade drainage features
such as a stream, wetland, lake, or ditch.
4.1.7 Dewatering Control
During the initial phase of work, the site will be excavated in phases to limit soil disturbance and
prevent contaminated stormwater from leaving the site. A baker tank system will be onsite to
store all dewatering water from active excavations. The Baker Tank treatment system will
discharge to the King County Sewer under an approved discharge permit. In the event that the
Baker Treatment system does not provide adequate treatment levels under the permit the
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contractor shall be responsible to have the stormwater / dewatering disposed by an authorized
facility.
4.1.8 Dust Control
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. Water shall
be used on exposed soils by spraying until wet, but runoff shall not be generated by spraying.
Exposed areas shall be resprayed as needed. Oil shall not be used for dust control.
4.1.9 Flow Control
Perimeter controls along with the Baker Tanks will control stormwater during the initial clean-up
phase of work. Unworked portions of the site are currently impervious graveled storage yard that
discharge off-site.
As the cleanup progresses and the site is re-graded and stabilized with rock and straw mulch
additional controls will be installed including interceptor swales along the perimeter to collect
surface runoff and route it to onsite temporary sediment traps in the southwest and northeast
corners of the site. The southwest sediment trap will have a riser structure with a discharge to the
storm network in East Valley Road. The northeast sediment trap will discharge to a ditch that will
empty into the offsite wetland. See Appendix E for sediment trap sizing.
4.1.10 Control Pollutants
Stormwater Pollution Prevention and Spill (SWPPS) measures are required to prevent, reduce, or
eliminate the discharge of pollutants to onsite or adjacent stormwater systems or watercourses
for construction-related activities. Section 5.0 identifies these SWPPS measures.
This site has contaminated soils. Soil remediation will be conducted in accordance with Stemen
Environmental Voluntary Clean Up Scope of work (dated April 23, 2018) and the Departm ent of
Ecology NPDES Permit requirements. A No Further Action Letter will be obtained prior to
constructing the future development.
4.1.11 Protect Existing and Proposed Flow Control BMPs
Protection measures shall be applied/installed and maintained to prevent ad verse impacts to
areas of proposed flow control BMPs within the project site. There are no known existing flow
control BMPs located on the project site.
The contractor is responsible for protecting flow control BMPs.
4.1.12 Maintain BMPs
Protection measures, per BMP D.2.1.11, shall be maintained to assure continued performance of
their intended function and protect other disturbed areas of the project. There are no known
existing flow control BMPs located on the project site.
The Contractor is responsible for maintaining all temporary and permanent BMPs.
4.1.13 Manage the Project
Coordination and timing of site development activities relative to ESC concerns (Section D.2.4 of
the CRSWDM) and timely inspection, maintenance, and update of protective measures
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(Section D.2.3 of the CRSWDM) are necessary to effectively manage the project and assure the
success of protective ESC and SWPPS design and implementation.
PBS Environmental will be the CESCL for the project to ensure proper maintenance of erosion
control BMPs, discharge of stormwater to acceptable levels in accordance with the NPDES
permit, and maintaining and updating the onsite SWPPP.
4.2 Erosion Problem Areas
The erosion potential of the site soils is moderate to low, as there are no known historic erosion
problems within or around the project site. Refer to Appendix B for recommended King County
Source Control BMPs.
5.0 Stormwater Pollution Prevention and Spill (SWPPS) Plan Design (Part B)
The Stormwater Pollution Prevention and Spill (SWPPS) Plan includes three elements: a site plan
(Sheets C1.1, C2.1), provided in Appendix A), a pollution prevention report (this document), and a
spill prevention and cleanup report. The spill prevention and cleanup report includes identifying
the expected sources of potential pollution and spills that may occur during construction, and
works to develop a plan to prevent pollution and spills. It also develops a plan to mitigate spills
that may occur. The SWPPS Plan will be kept onsite at all times during construction. The
General Contractor will be responsible to ensure that subcontractors are aware of the SWPPS
Plan, and a form or record will be provided stating that all subcontractors have read and agree to
the SWPPS Plan. An employee training worksheet is provided for the Contractor’s use (see
Appendix C).
A SWPPS Site Plan has been submitted with the civil engineering plans and can be found in
Appendix A on Sheets C1.1 (Demo, Excavation, And Cleanup Plan), C2.1 (Rough Grading and
TESC plan) and C3.1 and C3.2 (TESC Notes and Details). The SWPPS Site Plan, Pollution
Prevention Report, and Spill Prevention and Cleanup Report have been developed , and BMPs
have been selected based on Section 2.3.1.4 of the CRSWDM and the King County Stormwater
Pollution Prevention Manual (KCSPPM).
5.1 Pollution and Spill Prevention Source Controls and BMPs
The sources of pollution and spills will be identified by the Contractor in the spaces provided
below, and the BMPs to be used for each source for prevention of both pollution and spills will be
provided by the Contractor in the spaces provided below:
Liquids shall not be stored onsite.
Dry pesticides and fertilizers shall be covered with plastic sheeting or stored in a sealed
container. Materials shall be stored on pallets or another raised method to prevent contact with
stormwater runoff. Alternatively, the materials shall be contained in a manner such that if the
container leaks or spills, the contents will not discharge, flow, or be washed into the storm
drainage system, surface waters, or groundwater. Maintenance requirements are the same as
liquid materials described above.
Chemicals shall not be stored onsite.
Soil, sand, and other erodible materials shall be covered with plastic sheeting per Detail 6 on
Sheet C203. Perimeter controls shall be constructed as shown on the TESC plan to prevent
eroded materials from leaving the project site.
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Fueling shall not occur onsite. If fueling does occur onsite, the Contractor shall develop a
containment plan for spills and provide lighting and signage if fueling occurs at night in
conformance with the KCSPPM.
Maintenance and repair of vehicles shall not occur onsite. If maintenance or repair of vehicles
does occur onsite, the Contractor shall develop a spill prevention plan in Conformance with the
KCSPPM.
Truck wheel washing, if required, shall occur at a wheel wash station as shown on City of
Renton Standard Plan 215.00. All other vehicle washing shall occur in a controlled manner,
such that runoff is collected and disposed of in a legal manner. Washing areas must be lined with
an impervious membrane to prevent contamination of groundwater.
Rinsing of hand tools is not applicable at this site.
Contaminated soils shall be covered with plastic sheeting or contained to prevent stormwater
from carrying pollutants away to surface or ground waters. Appropriate spill cleanup materials,
such as brooms, dustpans, vacuum sweepers, etc., shall be stored and maintained near the
storage area. Contractor shall refer to the NPDES administrative order for removal of
contaminated soils. Area shall not be hosed down such that water drains to the storm drainage
system, groundwater, surface water, or neighboring areas.
During concrete and asphalt construction, NOT APPLICABLE TO THIS PHASE OF WORK.
Water with elevated pH levels shall not be discharged from the site. Contractor shall monitor
stormwater for pH prior to discharging from the site. Contractor shall implement a pH treatment
plan if pH is not within the natural range
5.2 Responsible Personnel and Contact Information
Jake Riley with PBS Engineering + Environmental shall be responsible for pollution and spill
prevention and cleanup and can be contacted (206) 473-2542 or JAKE_RILEY@PBSENV.COM.
Contractor shall fill out the attached Pollution Prevention Team Worksheet (see Appendix C).
5.3 Pollution and Spill Prevention Worksheets
Pollution prevention, BMP implementation reports, material inventory worksheets, pollutant
source identification worksheet, and spill/leak report may be found attached as Appendix C.
5.4 Disposal Methods
Contractor shall dispose of contaminated soils and water in a legal manner. Options include the
following: Disposal at a local landfill or at a recycling center, as allowed.
6.0 ESC Performance and Compliance Provisions
6.1 ESC Supervisor
The Contractor shall appoint a Certified Erosion and Sediment Control Lead (CESCL) or Certified
Professional in Erosion and Sediment Control (CPESC) (BMP D.4.1) for the project, and the
appointee must be approved by the City.
The duties of the CESCL or CPESC include:
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Maintaining files onsite at all times, which include the Construction SWPPP and any
associated permits and plans.
Directing BMP installation, inspection, maintenance, modification, and removal.
Keeping a log of all turbidity measurements taken onsite and making it available to City of
Renton Community & Economic Development upon request.
Updating all project drawings and the Construction SWPPP with changes made.
Keeping daily logs and inspection reports.
Facilitating, participating in, and taking corrective actions resulting from inspections
performed by outside agencies or the Owner.
To aid in the implementation of the Construction SWPPP, the members of the SWPP Team
include the following: the Contractor, the CESCL or CPESC, the City of Renton Inspector, and
AHBL. The General Contractor will ensure all housekeeping and monitoring procedures are
implemented, while the CESCL or CPESC will ensure the integrity of the structural BMPs. The
City of Renton Inspector and CESCL will observe construction and erosion control practices and
recommend revisions or additions to the Construction SWPPP and drawings.
6.2 Monitoring of Discharges
The ESC supervisor shall have a turbidity meter onsite and shall use it to monitor surface and
stormwater discharges from the project site whenever runoff occurs from onsite activities. A log
of all turbidity measurements taken onsite shall be kept and made available to the City of Renton
upon request.
6.3 ESC Performance
ECS measures shall be installed and maintained to prevent, to the maximum extent pract icable,
the transport of sediment from the project site to downstream drainage systems. Stormwater
turbidity shall be monitored based on Section D.4.3 of the CRSWDM.
6.4 Flexible Compliance
Any deviation to the Construction SWPPP will be documented and reported to the City for
approval.
6.5 Roads and Utilities Compliance
No alternative BMPs are used in road and utility compliance.
6.6 Alternative and Experimental Measures
No alternative or experimental measures are to be used at this time.
7.0 ESC Implementation Requirements
7.1 Wet Season Requirements
All of the following provisions for wet season construction are detailed in referenced sections:
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1. The allowed time that a disturbed area may remain unworked without cover measures is
reduced to two consecutive working days, rather than seven (D.3.2).
1. Stockpiles and steep cut and fill slopes are to be protected if unworked for more than
12 hours (D.3.2).
2. Cover materials sufficient to cover all disturbed areas shall be stockpiled onsite (D.3.2).
3. All areas that are to be unworked during the wet season shall be seeded within one week
of the beginning of the wet season (D.3.2.5).
4. Mulch is required to protect all seeded areas (D.3.2.1).
5. Fifty linear feet of filter fabric fence (and the necessary stakes) per acre of disturbance
must be stockpiled onsite (D.3.3.1).
6. Construction road and parking lot stabilization are required for all sites, unless the site is
underlain by coarse-grained soil (D.3.4.2).
7. Sediment retention is required unless no offsite discharge is anticipated for the specifie d
design flow (D.3.5).
8. Surface water controls are required, unless no offsite discharge is anticipated for the
specified design flow (D.3.6).
9. Phasing and more conservative BMPs must be evaluated for construction activity near
surface waters (D.5.3).
10. Any runoff generated by dewatering may be required to discharge to the sanitary sewer
(with appropriate discharge authorization), portable sand filter systems, or holding tanks
(D.2.1.7)
11. The frequency of maintenance review increases from monthly to weekly (D.5.4).
7.2 Critical Areas Restriction
There is a Category III wetland with a 75-foot buffer located directly to the east of the site. No
work will occur within the wetland as a part of the early clear and grade permit.
7.3 Maintenance Requirement
All ESC measures shall be maintained and reviewed on a regular basis, as prescribed in the
maintenance requirements for each BMP (see Appendix B). The ESC supervisor shall review the
site at least twice a month during the dry season, weekly during the wet season, and within
24 hours of significant storms. The City may require that a written record of these reviews be
kept onsite, with copies submitted to City of Renton Community & Economic Development within
48 hours.
Documentation
If DDES requires that a written record be maintained, a standard ESC Maintenance Report (D-95)
may be used. A copy of all required maintenance reports shall be kept onsite throughout the
duration of construction.
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The maintenance inspection report will be made after each inspection. Copies of th e report forms
to be completed by the Construction SWPPP Coordinator are included in Appendix C of this
Construction SWPPP. Completed forms will be provided to the City Inspector and will also be
maintained onsite during the entire construction project. If construction activities or design
modifications are made to the site plan that could impact stormwater, or if the Engineer of Record
determines that the measures are not adequate to prevent erosion and the discharge of sediment
from the site (based on turbidity measurements), this Construction SWPPP will be amended
appropriately. The amended Construction SWPPP will have a description of the new activities
that contribute to the increased pollutant loading and the planned source control activities.
Review Timing
During the wet season, weekly reviews shall be carried out every six to eight calendar days.
During the dry season, monthly reviews shall be carried out within three days of the calendar day
for the last inspection. Reviews shall also take place within 24 hours of significant storms. In
general, a significant storm is one with more than 0.5 inch of rain in 24 hours or less.
In order for the ESC facilities to function properly, they must be maintained and sediment
removed on a regular basis. Inspection and sediment removal shall be performed on all ESC
facilities, as described in the Inspection and Maintenance Report Forms included in Appendix C .
7.4 Construction Sequence
1. Hold the pre-construction meeting.
2. Post sign with name and phone number of ESC Supervisor (may be consolidated with the
required notice of construction sign).
3. Secure the project site with security fencing.
4. Flag or fence clearing limits as required. Maintain Existing Silt Fencing.
5. Install inlet sediment protection along frontage.
6. Grade and install construction entrance. Maintain existing entrance.
7. Deliver and Configure stormwater storage tanks. Maintain system for discharge to sewer in
accordance with King County Sewer Discharge Permit.
8. Maintain erosion control measures in accordance with City of Renton standards and
manufacturer’s recommendations.
9. Construct temporary sediment traps.
10. Relocate erosion control measures or install new measures so that, as site conditions
change, the erosion and sediment control is always in accordance with City of Renton
erosion and sediment control standards.
11. Cover all areas that will be unworked for more than seven days during the dry season or
two days during the wet season with straw, wood fiber mulch, compost, plastic sheeting, or
equivalent.
12. Stabilize all areas within seven days of reaching final grade.
ESC Plan for Construction Stormwater Pollution Prevention
Walker Auto Dealership 11
2180100.10
13. Seed, sod, stabilize, or cover any areas to remain unworked for more than 30 days.
14. The wetland buffer shall be restored in accordance with the landscape plans.
15. Upon completion of the project, stabilize all disturbed areas and remove BMPs , if
appropriate, and upon approval of the owner or engineer.
7.5 Final Stabilization
Prior to obtaining final construction approval, the site shall be stabilized, the structural ESC
measures such as silt fences removed, and drainage facilities cleaned.
To obtain final construction approval, the following conditions must be met:
1. All disturbed areas of the site shall be vegetated or otherwise permanently stabilized. At a
minimum, disturbed areas shall be seeded and mulched with a high likelihood that
sufficient cover will develop shortly after final approval. Mulch without seeding is not
adequate to allow final approval.
2. Structural measures, such as, but not limited to, filter fabric fences, pipe slope drains,
construction entrances, and storm drain inlet protection, shall be removed from the site.
Measures that will quickly decompose, such as brush barriers and organic mulches, may
be left in place. The City of Renton inspector must approve an applicant’s proposal to
remove fencing prior to the establishment of vegetation.
3. All permanent surface water facilities, including catch basins, manholes, pipes, ditches,
channels, flow control facilities, and water quality facilities, shall be cleaned. Any offsite
catch basin that required protection during construction shall also be cleaned
7.6 NPDES Requirements
The CRSWDM is equivalent to the EPA required NPDES permit through the Stormwater
Management Manual for Western Washington (Department of Ecology, 2012). The Department
of Ecology stormwater permit application requires the filling of a Notice of Intent (NOI) at least
30 days prior to the start of construction
7.7 Forest Practice Permit Requirements
The project does not clear more than 5,000 board feet of timber and does not require a Class IV
Special Forest Practice permit from the Washington State Department of Natural Resources.
8.0 Construction Schedule
Construction is scheduled to begin in fall 2018 and be completed by summer 2019.
This analysis is based on data and records either supplied to or obtained by AHBL . These documents
are referenced within the text of the analysis. The analysis has been prepared using procedures and
practices within the standard accepted practices of the industry. We conclude that this project, as
proposed, will not create any new problems within the existing downstream drainage system. This project
will not noticeably aggravate any existing downstream problems due to either water quality or quantity.
AHBL, Inc.
ESC Plan for Construction Stormwater Pollution Prevention
Walker Auto Dealership 12
2180100.10
Matt Whittlesey, EIT
Project Engineer
MKW /lsk
August 2018
Q:\2018\2180100\10_CIV\NON_CAD\REPORTS\SWPPP\20180802 Rpt (CSWPPP) _Early Start 2180100.10.docx
ESC Plan for Construction Stormwater Pollution Prevention
Walker Auto Dealership
2180100.10
Appendix A
Exhibits
A-1 .................... Vicinity Map
A-2 .................... Existing Conditions Map
C0.1 .................. Cover Sheet (Early Grading Permit)
C0.2 .................. Existing Conditions (Topographic Survey)
C0.3 .................. Test Pit and Excavation Map / Phasing Plan
C1.1 .................. Demo, Excavation, and Clean-Up Plan
C2.1 .................. Rough Grading and TESC Plan
C3.1 .................. TESC Notes and Details
C3.2 .................. TESC Notes an Details
2215 North 30th Street,
Suite 300,
Tacoma, WA 98403
253.383.2422 TEL
253.383.2572 FAX
JOB NO:
DATE:
WALKER AUTO DEALERSHIP
VICINITY MAP
SCALE: 1" = 1/4 MILE (1320')EX-1
5/31/18
2180100.10
N
SW 34TH ST 167
SITE
515
SW 27TH ST
LIND AVE SWE VALLEY RDTALBOT RD SSE CARR RD
SR 167SW 34TH ST EAST VALLEY ROADAHBL #103
REBAR AND CAP
N 167257.03
E 1297746.82
ELEV: 19.67
AHBL #104
REBAR AND CAP
N 166857.94
E 1297784.39
ELEV:20.22
75' WETLAND
BUFFER TO
BE RESTORED
PARCEL #3023059067
PARCEL #3023059090
EAST VALLEY RV AND BOAT STORAGE
PARCEL #3023059027
BRIGHT VIEW LANDSCAPING
PARCEL #1253600010
YOUNKER NISSAN
PARCEL #1253800030
HARTENG GLASS
CITY OF
RENTON
IN COMPLIANCE WITH CITY OF RENTON STANDARDS
Civil Engineers
Structural Engineers
Landscape Architects
Community Planners
Natural Resource Ecologists
Land Surveyors
Neighbors
T A C O M A
2215 North 30th Street, Suite 300 Tacoma, WA 98403
253.383.2422TEL 253.383.2572FAX www.ahbl.comWEB
S E A T T L E
S P O K A N E T R I - C I T I E S
WALKER AUTO DEALERSHIP
EARLY CLEAR AND GRADE PLANS
AHBL JOB #2180100.10
9
Know what's below.
before you dig.Call
RTED-40-4018C:18004244LUA:18-000305PR:18000212R-40180
N
GRAPHIC SCALE
0 50 100
1" = 50 FEET
25
PARCEL #3023059067
PER KING COUNTY ASSESSOR
THAT PORTION OF THE SOUTH 1/2 OF THE NORTHWEST 1/4 OF THE
SOUTHEAST 1/4 OF SECTION 30, TOWNSHIP 23 NORTH, RANGE 5 EAST
OF THE WILLAMETTE MERIDIAN LYING WESTERLY OF STATE
HIGHWAY #5. EXCEPT THE SOUTH 194 FEET THEREOF AND EXCEPT
THE WEST 30 FEET THEREOF.
LEGAL DESCRIPTION
NAVD 1988 VERTICAL DATUM ON ORTHOMETRICALLY CORRECTED
GPS OBSERVATIONS USING WSRN AND GEOID 2012A.
VERIFIED CITY OF RENTON 230
(CASE MONUMENT AT S 23RD ST AND WILLIAMS AVE CUL DE SAC)
ELEV: 230.75
VERTICAL DATUM
NAD 1983
WASHINGTON STATE PLANE NORTH PROJECTION, BASED ON GPS
OBSERVATIONS USING WSRN AND GEOID 2012A. UNITS OF
MEASUREMENT ARE US SURVEY FEET.
VERIFIED CITY OF RENTON 230
(CASE MONUMENT AT S 23RD ST AND WILLIAMS AVE CUL DE SAC)
BASIS OF BEARING
P
T
W
W
FOUND MONUMENT AS NOTED
SET REBAR AND CAP
FOUND PROPERTY CORNER
MONITORING WELL
BOLLARD
MAIL BOX
SIGN AS NOTED
TEST PIT
SANITARY SEWER CLEANOUT
SANITARY SEWER MANHOLE
STORM CATCH BASIN
STORM MANHOLE
CABLE RISER
GAS METER
GAS VALVE
TRAFFIC CABINET
POWER TRANSFORMER
GUY ANCHOR
UTILITY POWER POLE
JUNCTION BOX
POWER MANHOLE
POWER METER
LUMINAIRE
COMMUNICATIONS MANHOLE
TELEPHONE RISER
TELEPHONE VAULT
BLOW OFF VALVE
FIRE DEPARTMENT CONNECTION
FIRE HYDRANT
HOSE BIB
IRRIGATION CONTROL VALVE
WATER METER
WATER MANHOLE
POST INDICATOR VALVE
WATER VALVE
WATER VAULT
F-FIR, P-PINE
U-UNKNOWN
POWER VAULT
HB
ROOF DRAIN
STORM LINE
SEWER LINE
WATER LINE
GAS LINE
ELECTRICAL LINE
COMMUNICATION LINE
OVERHEAD UTILITIES
SPLIT RAIL FENCE
LEGEND
ASPHALT
CONCRETE
SILT FENCE
EXISTING PROPOSED
D&C INVESTMENT, LLC.
P.O. BOX 1657
TACOMA, WA 98401
CELL: (206) 391-0311
CONTACT: DALE WALKER
OWNER
CIVIL ENGINEER
SURVEYOR
AHBL
2215 NORTH 30TH STREET, SUITE 300
TACOMA, WA 98403
PH. (253) 383-2422
FAX (253) 383-2572
CONTACT: MATT WEBER, PE
AHBL
2215 NORTH 30TH STREET, SUITE 300
TACOMA, WA 98403
PH. (253) 383-2422
FAX (253) 383-2572
CONTACT: DAVE FOLLANSBEE, PLS
GEOTECHNICAL
MIGIZI GROUP, INC.
P.O. BOX 44840
TACOMA, WA 98448
PH: (253) 537-9400
CONTACT: JIM BRIGHAM, PE
IF WORKERS ENTER ANY TRENCH OR OTHER
EXCAVATION FOUR OR MORE FEET IN DEPTH THAT
DOES NOT MEET THE OPEN PIT REQUIREMENTS
OF WSDOT SECTION 2-09.3(3)B, IT SHALL BE
SHORED AND CRIBBED. THE CONTRACTOR ALONE
SHALL BE RESPONSIBLE FOR WORKER SAFETY
AND AHBL ASSUMES NO RESPONSIBILITY. ALL
TRENCH SAFETY SYSTEMS SHALL MEET THE
REQUIREMENTS OF THE WASHINGTON INDUSTRIAL
SAFETY AND HEALTH ACT, CHAPTER 49.17 RCW.
THE LOCATIONS OF EXISTING UNDERGROUND UTILITIES ARE
APPROXIMATE ONLY AND HAVE NOT BEEN INDEPENDENTLY
VERIFIED BY THE OWNER OR ITS REPRESENTATIVE. THE
CONTRACTOR SHALL DETERMINE THE EXACT LOCATION OF
ALL EXISTING UTILITIES BEFORE COMMENCING WORK AND
AGREES TO BE FULLY RESPONSIBLE FOR ANY AND ALL
DAMAGES THAT HAPPEN DUE TO THE CONTRACTOR'S
FAILURE TO LOCATE EXACTLY AND PRESERVE ANY AND ALL
UNDERGROUND UTILITIES. AHBL ASSUMES NO LIABILITY FOR
THE LOCATION OF UNDERGROUND UTILITIES.
FILL MATERIAL SHALL NOT CONTAIN PETROLEUM
PRODUCTS, OR SUBSTANCES WHICH ARE
HAZARDOUS, DANGEROUS, TOXIC, OR WHICH
OTHERWISE VIOLATE ANY STATE, FEDERAL, OR
LOCAL LAW, ORDINANCE, CODE, REGULATION,
RULE, ORDER, OR STANDARD.
UTILITY NOTE
FILL SPECIFICATION
TRENCH NOTE
3400 EAST VALLEY ROAD
RENTON, WA 98057
SITE ADDRESS
3023059067
PARCEL #
SHEET INDEX
SHEET NO.SHEET TITLE
C0.1 COVER SHEET
C0.2 EXISTING CONDITIONS
C1.1 TESC AND DEMOLITION PLAN
C2.1 ROUGH GRADING PLAN
C2.2 SITE SECTIONS
C2.3 SITE SECTIONS
C3.1 TESC NOTES AND DETAILS
C3.2 TESC NOTES AND DETAILS
COVER SHEET C0.1
1
1. SITE WILL BE BROKEN INTO APPROXIMATELY 4 WORK
SECTIONS. CLEAN SURFACE GRAVEL WILL BE SCRAPED AND
STOCKPILED.
2. EXCAVATE CONTAMINATED MATERIALS PER STEMEN
ENVIRONMENTAL'S RECOMMENDATIONS. EXCAVATED
MATERIAL SHALL BE STOCKPILED (UNDER COVER) DURING
CONTAMINATED SOIL SAMPLING AND TESTING.
3. EXCAVATE AND GRADE ACTIVE WORK SECTION TO
ACCOMMODATE 2.0' STRUCTURAL FILL SECTION (EXCEPT
BUFFER). REFER TO SITE CROSS SECTIONS.
4. IMPORT AND PLACE STRUCTURAL FILL PER GRADING PLAN
ON SHEET C2.1 AND PER GEOTECHNICAL ENGINEER'S
RECOMMENDATION. FINAL GRADES SHALL CORRESPOND TO
SUBGRADE FOR FUTURE BUILDING AND PAVEMENT SECTIONS.
5. GRADING SHALL BE OBSERVED BY THE GEOTECHNICAL
ENGINEER. COORDINATE COMPACTION TESTING WITH THE
GEOTECHNICAL ENGINEER.
EARTHWORK SEQUENCE
VICINITY MAP
SCALE: 1"=1/4 MILE
N
Q:\2018\2180100\10_CIV\CAD\_Fill and Grade\2180100-SH-COVR.dwgWALKER AUTO DEALERSHIP
EARLY CLEAR AND GRADE PLANS
SITE
SW 34TH ST
SW 27TH ST
LIND AVE SW167
515E VALLEY RDTALBOT RD SSE CARR RD
FUTURE CAR
DEALERSHIP
1
* REFER TO LANDSCAPE PLANS FOR
BUFFER RESTORATION
SPLIT RAIL
FENCE
WSDOT SERVICE
GATE
WSDOT SERVICE
GATE
6' CHAINLINK
SECURITY FENCE
WITH 3-STRAND
BARBWIRE
CHAINLINK FENCE
BUILDING OUTLINE
PAVEMENT OUTLINE
T EAST VALLEY ROADS.R. 167SW 34TH ST
CURVE TABLE
CURVE #LENGTH RADIUS DELTA CHORD DIRECTION CHORD LENGTH
VERTICAL DATUM BASIS OF BEARING
N
GRAPHIC SCALE
0 30 60 FEET
1" = 30 FEET
15
T
LEGEND
CITY OF
RENTON
IN COMPLIANCE WITH CITY OF RENTON STANDARDS
Civil Engineers
Structural Engineers
Landscape Architects
Community Planners
Natural Resource Ecologists
Land Surveyors
Neighbors
T A C O M A
2215 North 30th Street, Suite 300 Tacoma, WA 98403
253.383.2422TEL 253.383.2572FAX www.ahbl.comWEB
S E A T T L E
S P O K A N E T R I - C I T I E S
WALKER AUTO DEALERSHIP
EARLY CLEAR AND GRADE PLANS
AHBL JOB #2180100.10
9
Know what's below.
before you dig.Call
RTED-40-4018C:18004244LUA:18-000305PR:18000212R-40180
EXISTING CONDITIONS C0.2
2Q:\2018\2180100\10_CIV\CAD\_Fill and Grade\2180100-SH-EXST.dwg2
T EAST VALLEY ROADS.R. 167SW 34TH ST
CITY OF
RENTON
IN COMPLIANCE WITH CITY OF RENTON STANDARDS
Civil Engineers
Structural Engineers
Landscape Architects
Community Planners
Natural Resource Ecologists
Land Surveyors
Neighbors
T A C O M A
2215 North 30th Street, Suite 300 Tacoma, WA 98403
253.383.2422TEL 253.383.2572FAX www.ahbl.comWEB
S E A T T L E
S P O K A N E T R I - C I T I E S
WALKER AUTO DEALERSHIP
EARLY CLEAR AND GRADE PLANS
AHBL JOB #2180100.10
9
Know what's below.
before you dig.Call
RTED-40-4018C:18004244LUA:18-000305PR:18000212R-40180
B-1 B-2
B-3
B-4
DEPTH = 4FT
B-5
B-6
DEPTH = 3FT
B-7
B-8
B-9
B-10
DEPTH = 3FT
B-11
DEPTH = 3FT
B-12
B-13
B-14
B-15
DEPTH = 4FT
B-16
B-17
B-18
B-19
B-20
DEPTH = 5FT
R-1
R-2
R-3
R-4
R-5
R-6
S-3
S-1 S-2
S-11
S-9
S-30
S-7
DEPTH = 2FT
S-12
S-13 S-14
S-23
S-15
S-16
S-28 S-29
S-20
DEPTH = 3FT
S-6
S-17
S-18
S-21
S-19
S-26
S-25
S-22
DEPTH = 3FT
S-24
DEPTH = 3FT
S-8 S-27
S-10
DEPTH
= 10FT
APPROXIMATE LOCATION
OF TEST PITS
APPROXIMATE PROPERTY
BOUNDARY
APPROXIMATE BUILDING
OUTLINE
APPROXIMATE FENCE
LOCATION
APPROXIMATE BORING
LOCATION
APPROXIMATE DEPTH OF
"HOT SPOT" IDENTIFIED
SOIL CONTAMINATION
PHASE LINE
WORK AREA
PHASE 1
WORK AREA
PHASE 2
WORK AREA
PHASE 3
WORK AREA
PHASE 4
WORK AREA
PHASE 5
1.SAMPLING LOCATIONS LISTED ON
THIS SHEET PER KANE
ENVIRONMENTAL PROJECT NO.
51213 AS ANNOTATED BY STEMENS
ENVIRONMENTAL.
2.PHASE LINES ARE APPROXIMATE
AND SUBJECT TO CHANGE BASED
ON FIELD CONDITIONS.
DEPTH =
LEGEND
R / B - #
S - #
GENERAL NOTES
GRAPHIC SCALE
0 30 60
1" = 30 FEET
15
NPARKING LOT AND BUILDING
DEMOLITION IS LAST PHASE OF
CLEANUP. BUILDING WILL BE USED
AS CONSTRUCTION OFFICE.
C0.3
3
TEST PIT AND EXCAVATION MAP
PHASING PLAN
3
T SR 167SW 34TH ST EAST VALLEY ROAD5
5
1
2 (TYP.)
3 (TYP.)
4 (TYP.)
6
STCB 502 RIM=19.51
4" IP NE IE=16.60
12" CONC SW IE=13.76
NE PIPE CAPPED
SF
CL
CE
TEMPORARY STORM PIPE
40 LF 12" CPEP @ 1.0%
12" CPEP NE=13.71 (CORE & GROUT
NEW PIPE)
6
75.00'
FLAG THE
WETLAND BUFFER
WETLAND BOUNDARY
PROTECT
MONITORING
WELL (TYP.)
DEMO 6"
CPP'S
ID
RIDGE LINE
STRIPPED GRADE
CONTOUREXISTING GRADE
CONTOUR
-1.79-1.79
0.230.23
0.320.32
-0.16-0.16
-0.98-0.98
-1.59-1.59
1.411.41
1.111.11
0.960.96
0.320.32
1.271.27
1.861.86
1.501.50
2.422.42
0.510.51
-0.74-0.74
-0.29-0.29
-1.40-1.40
-2.31-2.31
-2.67-2.67
-2.17-2.17
-1.66-1.66
-2.74-2.74
-2.94-2.94
-1.79-1.79
1.051.05
1.331.33
0.820.82
0.560.56
1.821.82
1.871.87
1.641.64
1.781.78
0.950.95
0.100.10
-0.71-0.71
-1.60-1.60
-2.21-2.21
-2.22-2.22
-2.07-2.07
-1.64-1.64
-1.77-1.77
-2.48-2.48
-1.82-1.82
0.960.96
1.531.53
0.760.76
1.041.04
1.221.22
1.231.23
1.511.51
1.621.62
1.431.43
1.091.09
-1.39-1.39
-1.87-1.87
-2.66-2.66
-2.80-2.80
-2.69-2.69
-2.47-2.47
-2.19-2.19
-2.11-2.11
-1.90-1.90
0.400.40
1.241.24
1.081.08
0.750.75
0.890.89
1.471.47
1.501.50
1.341.34
0.650.65
-0.19-0.19
-2.46-2.46
-2.11-2.11
-3.01-3.01
-3.24-3.24
-2.94-2.94
-2.94-2.94
-2.77-2.77
-2.84-2.84
-2.00-2.00
-0.07-0.07
1.081.08
0.560.56
1.071.07
0.980.98
1.781.78
1.231.23
0.630.63
-0.47-0.47
-1.79-1.79
-2.06-2.06
-2.76-2.76
-3.14-3.14
-3.26-3.26
-3.43-3.43
-3.37-3.37
-3.40-3.40
-2.97-2.97
-1.89-1.89
0.410.41
1.171.17
0.850.85
1.021.02
1.021.02
2.062.06
1.511.51
0.590.59
-0.52-0.52
-1.63-1.63
-2.64-2.64
-2.86-2.86
-3.18-3.18
-3.37-3.37
-3.67-3.67
-3.56-3.56
-3.29-3.29
-2.81-2.81
-1.95-1.95
-0.22-0.22
0.800.80
0.890.89
1.021.02
1.671.67
2.152.15
1.651.65
0.600.60
-0.74-0.74
-1.84-1.84
-2.64-2.64
-2.86-2.86
-3.16-3.16
-3.48-3.48
-3.56-3.56
-3.12-3.12
-2.72-2.72
-2.13-2.13
-2.35-2.35
-1.12-1.12
-0.41-0.41
0.050.05
1.031.03
1.961.96
2.172.17
1.621.62
0.450.45
-1.07-1.07
-1.60-1.60
-2.05-2.05
-2.58-2.58
-3.04-3.04
-3.07-3.07
-3.20-3.20
-2.72-2.72
-2.19-2.19
-1.96-1.96
-2.71-2.71
-1.29-1.29
-0.65-0.65
-0.09-0.09
0.920.92
1.651.65
2.002.00
1.411.41
0.460.46
-1.17-1.17
-1.42-1.42
-1.86-1.86
-2.43-2.43
-3.07-3.07
-3.25-3.25
-3.34-3.34
-2.87-2.87
-2.25-2.25
-1.51-1.51
-2.71-2.71
-1.39-1.39
-0.50-0.50
0.090.09
0.940.94
1.501.50
1.641.64
1.101.10
0.250.25
-1.32-1.32
-1.57-1.57
-1.95-1.95
-2.35-2.35
-3.00-3.00
-3.03-3.03
-3.07-3.07
-2.68-2.68
-2.28-2.28
-1.89-1.89
-2.61-2.61
-1.91-1.91
-0.97-0.97
-0.37-0.37
0.660.66
1.041.04
1.021.02
0.910.91
-0.31-0.31
-1.67-1.67
-2.24-2.24
-2.41-2.41
-2.49-2.49
-2.77-2.77
-2.85-2.85
-3.00-3.00
-2.65-2.65
-2.21-2.21
-2.27-2.27
-2.08-2.08
-1.87-1.87
-1.26-1.26
-0.97-0.97
0.170.17
0.400.40
0.140.14
0.230.23
-1.15-1.15
-1.90-1.90
-2.23-2.23
-2.27-2.27
-2.45-2.45
-2.53-2.53
-2.83-2.83
-2.62-2.62
-2.28-2.28
-1.65-1.65
-0.39-0.39
-1.91-1.91
-1.45-1.45
-0.63-0.63
-0.43-0.43
-0.21-0.21
-0.23-0.23
-0.57-0.57
-0.75-0.75
-1.44-1.44
-2.08-2.08
-2.26-2.26
-2.22-2.22
-2.36-2.36
-2.65-2.65
-2.71-2.71
-2.65-2.65
-2.39-2.39
-1.87-1.87
-1.48-1.48
-1.67-1.67
-1.15-1.15
-0.54-0.54
-0.31-0.31
-0.22-0.22
-0.62-0.62
-1.01-1.01
-1.52-1.52
-1.71-1.71
-2.21-2.21
-2.23-2.23
-1.93-1.93
-2.02-2.02
-1.97-1.97
-2.07-2.07
-2.10-2.10
-2.07-2.07
-2.05-2.05
-0.72-0.72
-1.98-1.98
-1.68-1.68
-1.20-1.20
-1.03-1.03
-0.93-0.93
-1.21-1.21
-1.65-1.65
-1.70-1.70
-1.88-1.88
-1.97-1.97
-1.95-1.95
-1.81-1.81
-1.62-1.62
-1.46-1.46
-1.48-1.48
-1.53-1.53
-1.47-1.47
-1.33-1.33
-0.38-0.38
-2.16-2.16
-1.79-1.79
-1.62-1.62
-1.56-1.56
-1.56-1.56
-1.40-1.40
-1.46-1.46
-1.52-1.52
-1.77-1.77
-1.93-1.93
-1.88-1.88
-1.71-1.71
-1.49-1.49
-1.38-1.38
-1.21-1.21
-0.89-0.89
-0.64-0.64
-0.53-0.53
-0.95-0.95
-1.67-1.67
-1.60-1.60
-1.62-1.62
-1.61-1.61
-1.57-1.57
-1.51-1.51
-1.70-1.70
-1.76-1.76
-1.58-1.58
-1.41-1.41
-1.40-1.40
-1.26-1.26
-1.08-1.08
-0.83-0.83
-0.67-0.67
-0.36-0.36
0.390.39
-1.40-1.40
-1.32-1.32
-1.26-1.26
-1.08-1.08
-0.90-0.90
-0.74-0.74
-0.62-0.62
-0.38-0.38
0.280.28
-0.27-0.27
WETLAND BUFFER TO
BE RESTORED. REFER
TO LANDSCAPE PLAN.
0.590.59
LOCATE EXISTING SEWER STUB.
DISCHARGE TO SEWER UNDER
APPROVED DISCHARGE PERMIT AND
PROVIDE SURFACE CLEANOUT FOR
DISCHARGE.
TEMPORARY
STORMWATER TANKS
FOR TREATMENT
PUMP SUCTION
MAINTAIN CONSTRUCTION
ENTERANCE
(TYP)
5
MINIMUM EXCAVATION
DEPTH TO SUBGRADE
(TYP.)
MH 2987
CE
CITY OF
RENTON
IN COMPLIANCE WITH CITY OF RENTON STANDARDS
Civil Engineers
Structural Engineers
Landscape Architects
Community Planners
Natural Resource Ecologists
Land Surveyors
Neighbors
T A C O M A
2215 North 30th Street, Suite 300 Tacoma, WA 98403
253.383.2422TEL 253.383.2572FAX www.ahbl.comWEB
S E A T T L E
S P O K A N E T R I - C I T I E S
WALKER AUTO DEALERSHIP
EARLY CLEAR AND GRADE PLANS
AHBL JOB #2180100.10
9
Know what's below.
before you dig.Call
RTED-40-4018C:18004244LUA:18-000305PR:18000212R-40180
N
GRAPHIC SCALE
0 30 60
1" = 30 FEET
15
TESC AND DEMO LEGEND
INLET PROTECTION
SILT FENCE
CLEARING LIMITS
DEMO EXISTING UTILITY
CONSTRUCTION ENTRANCE
REMOVE EXISTING ASPHALT
REMOVE EXISTING CONCRETE
REMOVE EXISTING BUILDING
REMOVE EXISTING FENCE
EXISTING GRADE CONTOUR
CL
SF
IP
DEMO, EXCAVATION, AND CLEAN-UP PLAN
C1.1
4
COVER ALL CONTAMINATED SOIL STOCKPILES
STRAW COVER ALL DISTURBED AREAS.
KEY NOTES
REMOVE EXISTING BUILDING (REFER TO
SEPARATE DEMOLITION PERMIT)
REMOVE EXISTING CURB
REMOVE EXISTING WHEEL STOPS
REMOVE EXISTING FENCE
REMOVE STORM PIPE
CAP EXISTING UTILITY AND ABANDON PER CITY
OF RENTON AND PURVEYOR STANDARDS
1
2
3
4
5
6
CE
WETLAND BUFFER NOTE
RESTORATION OF THE ONSITE WETLAND BUFFER SHALL
CONSIST OF REMOVAL OF EXISTING GRAVEL AND
PLACEMENT OF 3" BARK MULCH OVER 18" OF
BIO-RETENTION SOIL MIX. SOIL MIX SHALL CONFORM TO
CITY OF RENTON SWDM SECTION 11-C.2
Q:\2018\2180100\10_CIV\CAD\_Fill and Grade\2180100-SH-TESC.dwgELEV
EXCAVATION/STORMWATER NOTES
1.DURING THE EXCAVATION AND CLEANUP PHASE, DISCHARGE STORMWATER FROM PUMP TO (2)
TEMPORARY STORMWATER TANKS.
1.1.TANKS SHALL BE BAKER TANK OR APPROVED EQUAL.
1.2.STORMWATER FROM THE TANKS MUST BE DISCHARGED OFF-SITE OR AS APPROVED IN THE
KING COUNTY DISCHARGE PERMIT.
1.3.ANY PERMIT OR OTHER FEES ASSOCIATED WITH DISCHARGES ARE THE RESPONSIBILITY OF
THE CONTRACTOR.
1.4.LOCATIONS SHOWN ON PLAN ARE SUGGESTIONS ONLY. THE CONTRACTOR WILL DECIDE
THE LOCATIONS OF THE TANKS.
2.SCRAPE CLEAN SURFACE GRAVELS FROM WORK AREA FOR REUSE ONSITE.
3.EXCAVATE CONTAMINATED SOILS AS REQUIRED TO MEET CLEANUP LEVELS. HAUL ALL
CONTAMINATED SOIL TO AN AUTHORIZED DISPOSAL SITE.
4.PROTECT RECLAIMED AREAS FROM RE-CONTAMINATION.
FORCE MAIN LINE IS DIAGRAMATIC. SITE WILL BE
EXCAVATED IN SECTIONS. SUCTION WILL BE
MAINTAINED AT ACTIVE EXCAVATIONS AS NEEDED
FOR DEWATERING.
IP (TYP.)
CONTRACTOR TO PROTECT EXISTING BUILDING
AND STORM DRAIN SYSTEM. EXCAVATION SHALL
NOT ENTER ZONE OF INFLUENCE OF BUILDING
FOUNDATION.
4
T
0+00 1+00 2+00 3+00 4+00 5+00 6+00 6+50
0+00 1+00 2+00 3+00 4+00 5+00 6+00 6+50
0+00 1+00 2+00 3+00 4+00 5+00 6+00 6+50
A
C2.2
B
C2.2
C
C2.2
0+001+002+003+004+005+005+250+001+002+003+004+005+005+250+001+002+003+004+005+005+25D
C2.3
E
C2.3
F
C2.3
FUTURE BUILDING
PAD SUBGRADE ELEV: 21.25 SR 167SW 34TH ST EAST VALLEY ROADFS: 18.07FS: 17.67FS: 13.71FS: 13.71FS: 18.03FS: 20.55FS: 20.48FS: 20.51FS: 20.55FS: 20.09FS: 19.34FS: 20.60FS: 20.56FS: 20.48FS: 20.39FS: 20.30FS: 20.17FS: 18.75FS: 18.66FS: 18.14FS: 17.52FS: 13.71FS: 13.71FS: 18.19FS: 20.57FS: 20.42FS: 20.08FS: 20.39FS: 20.21FS: 19.94FS: 20.51FS: 20.59FS: 20.54FS: 20.48FS: 20.43FS: 20.24FS: 19.67FS: 19.68FS: 18.69FS: 17.36FS: 13.71FS: 13.71FS: 18.34FS: 20.57FS: 20.55FS: 20.55FS: 20.55FS: 20.55FS: 20.64FS: 20.68FS: 20.69FS: 20.60FS: 20.56FS: 20.57FS: 20.54FS: 20.58FS: 20.57FS: 19.16FS: 17.21FS: 13.71FS: 13.71FS: 18.50FS: 20.47FS: 21.10FS: 20.94FS: 20.89FS: 20.88FS: 20.92FS: 20.57FS: 20.37FS: 20.22FS: 20.19FS: 20.14FS: 20.13FS: 19.57FS: 17.06FS: 13.71FS: 13.71FS: 18.65FS: 20.61FS: 21.17FS: 20.50FS: 20.32FS: 20.12FS: 19.90FS: 19.69FS: 19.82FS: 19.57FS: 16.91FS: 13.71FS: 13.71FS: 18.80FS: 20.74FS: 21.19FS: 20.28FS: 20.08FS: 19.87FS: 19.85FS: 19.91FS: 19.75FS: 16.75FS: 13.71FS: 13.71FS: 18.95FS: 20.99FS: 21.23FS: 20.26FS: 20.27FS: 20.29FS: 20.30FS: 20.31FS: 20.09FS: 16.60FS: 13.71FS: 13.71FS: 19.11FS: 21.25FS: 21.25FS: 20.48FS: 20.46FS: 20.45FS: 20.43FS: 20.42FS: 20.54FS: 16.45FS: 13.71FS: 13.71FS: 19.26FS: 21.25FS: 21.25FS: 20.29FS: 20.09FS: 19.96FS: 19.95FS: 19.95FS: 20.56FS: 20.06FS: 19.89FS: 19.78FS: 20.38FS: 21.25FS: 21.25FS: 20.33FS: 20.14FS: 19.93FS: 19.72FS: 19.83FS: 20.41FS: 19.99FS: 19.75FS: 19.65FS: 20.37FS: 20.39FS: 20.27FS: 20.22FS: 20.18FS: 20.14FS: 19.95FS: 20.16FS: 19.75FS: 19.44FS: 20.51FS: 20.45FS: 20.49FS: 20.52FS: 20.56FS: 20.58FS: 19.92FS: 20.42FS: 20.27FS: 20.31FS: 20.70FS: 20.59FS: 20.37FS: 20.17FS: 20.20FS: 20.22FS: 20.00FS: 21.05FS: 21.04FS: 21.06FS: 21.17FS: 21.19FS: 20.75FS: 20.55FS: 20.28FS: 20.01FS: 20.17FS: 19.91FS: 20.80FS: 20.80FS: 20.83FS: 20.95FS: 21.12FS: 21.12FS: 21.09FS: 21.10FS: 21.11FS: 21.11FS: 21.10FS: 21.08FS: 21.05FS: 20.96FS: 20.75FS: 20.58FS: 20.41FS: 20.29FS: 19.44FS: 20.53FS: 20.54FS: 20.58FS: 20.68FS: 20.78FS: 20.79FS: 20.80FS: 20.81FS: 20.83FS: 20.85FS: 20.87FS: 20.89FS: 20.90FS: 20.92FS: 20.94FS: 20.96FS: 20.92FS: 20.79FS: 20.44FS: 20.28FS: 20.31FS: 20.37FS: 20.42FS: 20.46FS: 20.48FS: 20.50FS: 20.53FS: 20.56FS: 20.58FS: 20.61FS: 20.63FS: 20.66FS: 20.68FS: 20.71FS: 20.73FS: 20.79FS: 19.25FS: 20.19FS: 20.27FS: 20.30FS: 20.33FS: 20.36FS: 20.39FS: 20.42FS: 20.45FS: 20.47FS: 20.62FS: 19.25FS: 19.67FS: 20.46FUTURE BUILDING OUTLINE
FUTURE EDGE OF PAVING (TYP.)FS: 18.96FS: 18.48FS: 21.06FS: 20.86FS: 20.74FS: 20.73FS: 20.82FS: 20.54FS: 19.58FS: 18.37FS: 20.65FS: 20.51FS: 20.39FS: 20.39FS: 20.58FS: 20.71FS: 20.54FS: 20.46FS: 20.54FS: 20.47FS: 20.38FS: 20.23FS: 20.15FS: 20.04FS: 20.10FS: 18.12FS: 18.94FS: 20.10FS: 19.80FS: 20.11FS: 20.22FS: 20.40FS: 20.33FS: 20.36FS: 20.03FS: 19.98FS: 19.95FS: 19.81FS: 19.61FS: 19.53FS: 19.37FS: 19.39FS: 19.37FS: 18.80FS: 19.43FS: 19.57FS: 19.16FS: 19.49FS: 19.20FS: 19.20FS: 18.95FS: 18.96FS: 19.01FS: 18.97FS: 18.40FS: 18.12FS: 17.62STRIPPED GRADE
CONTOUR
FINAL SUBGRADE
CONTOUR
TEMPORARY STORM PIPE
40 LF 12" CPEP @ 1.0%
SEDIMENT TRAP RISER
12" CPEP SW=14.0
TEMPORARY SEDIMENT TRAP
MIN. SURFACE AREA:1800 SF
BERM ELEV: 19.0
WS ELEV: 18.0
BOTTOM ELEV: 14.5
BERM ELEV: 19.0
BOTTOM ELEV: 14.5
RR
RR
SPILLWAY ELEV: 18.0
SF
MAINTAIN CONSTRUCTION
ENTERANCE
(TYP)
HIGH POINTFS: 21.03FS: 21.05FS: 21.09FS: 20.47FS: 21.10FS: 20.46FS: 21.11FS: 20.50FS: 21.11FS: 20.47FS: 21.11FS: 20.50FS: 21.16FS: 20.56FS: 21.12FS: 21.10FS: 21.18FS: 20.65FS: 21.02FS: 20.90TEMPORARY SEDIMENT TRAP
MIN. SURFACE AREA:1900 SF
BERM ELEV: 16.5
WS ELEV: 15.5
BOTTOM ELEV: 12.0
BERM ELEV: 16.5
BOTTOM ELEV: 12.0
REFER TO LANDSCAPE PLANS FOR
BUFFER RESTORATION2020202121
21
20
21212
1
20201920 2019CONTRACTOR TO PROTECT EXISTING BUILDING
AND STORM DRAIN SYSTEM. EXCAVATIONS SHALL
NOT ENTER ZONE OF INFLUENCE OF BUILDING
FOUNDATION.
OUTER SILT FENCE
CAN BE REMOVED
WHEN BUFFER IS
STABILIZED
N
GRAPHIC SCALE
0 30 60
1" = 30 FEET
15
EARTHWORK VOLUMES
ANTICIPATED CONTAMINATED SOIL REMOVAL
(ASSUMING 1' DEPTH OF REMOVAL): 9,100 CY
CUT:7,000 CY
FILL:19,800 CY
NET:12,800 (IMPORT)
NOTE:
VOLUMES ARE STRIPPED GRADE TO FINAL SUBGRADE.
THE ABOVE QUANTITIES ARE ESTIMATES ONLY
INTENDED FOR THE PERMITTING PROCESS. DO NOT
USE FOR BID PURPOSES. THE QUANTITIES DO NOT
HAVE STRIPPING, COMPACTION, OR CUT OR FILL
ADJUSTMENT FACTORS APPLIED TO THEM.
CITY OF
RENTON
IN COMPLIANCE WITH CITY OF RENTON STANDARDS
Civil Engineers
Structural Engineers
Landscape Architects
Community Planners
Natural Resource Ecologists
Land Surveyors
Neighbors
T A C O M A
2215 North 30th Street, Suite 300 Tacoma, WA 98403
253.383.2422TEL 253.383.2572FAX www.ahbl.comWEB
S E A T T L E
S P O K A N E T R I - C I T I E S
WALKER AUTO DEALERSHIP
EARLY CLEAR AND GRADE PLANS
AHBL JOB #2180100.10
9
Know what's below.
before you dig.Call
RTED-40-4018C:18004244LUA:18-000305PR:18000212R-40180
ROUGH GRADING AND TESC PLAN
C2.1
5
STABILIZE ALL DISTURBED AREAS
WITH ROCK SURFACING AND STRAW
Q:\2018\2180100\10_CIV\CAD\_Fill and Grade\2180100-SH-GRAD.dwgEATHWORK LEGEND
FS = FINAL SUBGRADE
FINAL SUBGRADE CONTOUR
STRIPPED SURFACE CONTOUR
NOTE: FINAL SUBGRADE SHALL BE UNDERLAIN BY 2.0'
OF STRUCTURAL FILL IN BUILDING AND PAVED AREAS
PER GEOTECHNICAL ENGINEER'S RECOMMENDATION.
ELEV
ELEV
75.00' WETLAND
BUFFER
TESC LEGEND
RIPRAP ROCKERY
6"-8" QUARRY SPALLS
GRAVEL CHECK DAM
INTERCEPTOR DITCH
@ 0.3% MINIMUM
INLET PROTECTION
SILT FENCE
CLEARING LIMITS
SEDIMENT TRAP RISER
CONSTRUCTION ENTRANCE
CL
SF
IP
ID
CD
RR
CE
CE
CE
SF
ID
ID
ID
SF
SF
SF
SF
5
CITY OF
RENTON
IN COMPLIANCE WITH CITY OF RENTON STANDARDS
Civil Engineers
Structural Engineers
Landscape Architects
Community Planners
Natural Resource Ecologists
Land Surveyors
Neighbors
T A C O M A
2215 North 30th Street, Suite 300 Tacoma, WA 98403
253.383.2422TEL 253.383.2572FAX www.ahbl.comWEB
S E A T T L E
S P O K A N E T R I - C I T I E S
WALKER AUTO DEALERSHIP
EARLY CLEAR AND GRADE PLANS
AHBL JOB #2180100.10
9
Know what's below.
before you dig.Call
RTED-40-4018C:18004244LUA:18-000305PR:18000212R-40180
TESC NOTES AND DETAILS C3.1
8Q:\2018\2180100\10_CIV\CAD\_Fill and Grade\2180100-SH-TESC.dwg1.BEFORE ANY CONSTRUCTION OR DEVELOPMENT ACTIVITY OCCURS, A
PRE-CONSTRUCTION MEETING SHALL BE HELD AMONG THE CITY OF
RENTON, HEREBY REFERRED TO AS THE CITY, THE APPLICANT, AND THE
APPLICANT’S CONTRACTOR.
2.THE APPLICANT IS RESPONSIBLE FOR OBTAINING THE WASHINGTON
STATE DEPARTMENT OF ECOLOGY (ECOLOGY) CONSTRUCTION
STORMWATER GENERAL PERMIT, IF IT IS REQUIRED FOR THE PROJECT.
THE APPLICANT SHALL PROVIDE THE CITY COPIES OF ALL MONITORING
REPORTS PROVIDED TO ECOLOGY ASSOCIATED WITH THE
CONSTRUCTION STORMWATER GENERAL PERMIT.
3.THE ESC PLAN SET SHALL INCLUDE AN ESC CONSTRUCTION
SEQUENCE DETAILING THE ORDERED STEPS THAT SHALL BE FOLLOWED
FROM THE PRE-CONSTRUCTION MEETING TO POST-PROJECT CLEANUP
IN ORDER TO FULFILL PROJECT ESC REQUIREMENTS.
4.THE BOUNDARIES OF THE CLEARING LIMITS, SENSITIVE AREAS AND
THEIR BUFFERS, AND AREAS OF VEGETATION PRESERVATION AND TREE
RETENTION, AS PRESCRIBED ON THE PLAN(S), SHALL BE CLEARLY
FLAGGED BY SURVEY TAPE OR FENCING AND PROTECTED IN THE FIELD
IN ACCORDANCE WITH APPENDIX D OF THE CITY OF RENTON
SURFACE WATER DESIGN MANUAL (RSWDM) PRIOR TO CONSTRUCTION.
DURING THE CONSTRUCTION PERIOD, NO DISTURBANCE BEYOND THE
CLEARING LIMITS SHALL BE PERMITTED. THE CLEARING LIMITS SHALL BE
MAINTAINED BY THE APPLICANT/ESC SUPERVISOR FOR THE DURATION
OF CONSTRUCTION.
5.STABILIZED CONSTRUCTION ENTRANCES SHALL BE INSTALLED AT THE
BEGINNING OF CONSTRUCTION AND MAINTAINED FOR THE DURATION
OF THE PROJECT. ADDITIONAL MEASURES, SUCH AS CONSTRUCTED
WHEEL WASH SYSTEMS OR WASH PADS, MAY BE REQUIRED TO ENSURE
THAT ALL PAVED AREAS ARE KEPT CLEAN AND TRACK-OUT TO ROAD
RIGHT OF WAY DOES NOT OCCUR FOR THE DURATION OF THE PROJECT.
IF SEDIMENT IS TRACKED OFFSITE, PUBLIC ROADS SHALL BE CLEANED
THOROUGHLY AT THE END OF EACH DAY, OR MORE FREQUENTLY
DURING WET WEATHER, AS NECESSARY TO PREVENT SEDIMENT FROM
ENTERING WATERS OF THE STATE.
6.WASHOUT FROM CONCRETE TRUCKS SHALL BE PERFORMED OFF-SITE
OR IN DESIGNATED CONCRETE WASHOUT AREAS ONLY. DO NOT WASH
OUT CONCRETE TRUCKS ONTO THE GROUND, OR TO STORM DRAINS OR
OPEN DITCHES. ON-SITE DUMPING OF EXCESS CONCRETE SHALL ONLY
OCCUR IN DESIGNATED CONCRETE WASHOUT AREAS.
7.ALL REQUIRED ESC BMPS SHALL BE CONSTRUCTED AND IN
OPERATION PRIOR TO LAND CLEARING AND/OR CONSTRUCTION TO
PREVENT TRANSPORTATION OF SEDIMENT TO SURFACE WATER,
DRAINAGE SYSTEMS AND ADJACENT PROPERTIES. ALL ESC BMPS SHALL
BE MAINTAINED IN A SATISFACTORY CONDITION UNTIL SUCH TIME
THAT CLEARING AND/OR CONSTRUCTION IS COMPLETE AND POTENTIAL
FOR ON-SITE EROSION HAS PASSED. ALL ESC BMPS SHALL BE REMOVED
AFTER CONSTRUCTION IS COMPLETED AND THE SITE HAS BEEN
STABILIZED TO ENSURE POTENTIAL FOR ON-SITE EROSION DOES NOT
EXIST. THE IMPLEMENTATION, MAINTENANCE, REPLACEMENT,
ENHANCEMENT, AND REMOVAL OF ESC BMPS SHALL BE THE
RESPONSIBILITY OF THE APPLICANT.
8.ANY HAZARDOUS MATERIALS OR LIQUID PRODUCTS THAT HAVE THE
POTENTIAL TO POLLUTE RUNOFF SHALL BE DISPOSED OF PROPERLY.
9.THE ESC BMPS DEPICTED ON THIS DRAWING ARE INTENDED TO BE
MINIMUM REQUIREMENTS TO MEET ANTICIPATED SITE CONDITIONS. AS
CONSTRUCTION PROGRESSES AND UNEXPECTED OR SEASONAL
CONDITIONS DICTATE, THE APPLICANT SHALL ANTICIPATE THAT MORE
ESC BMPS WILL BE NECESSARY TO ENSURE COMPLETE SILTATION
CONTROL ON THE PROPOSED SITE. DURING THE COURSE OF
CONSTRUCTION, IT SHALL BE THE OBLIGATION AND RESPONSIBILITY OF
THE APPLICANT TO ADDRESS ANY NEW CONDITIONS THAT MAY BE
CREATED BY THE ACTIVITIES AND TO PROVIDE ADDITIONAL ESC BMPS,
OVER AND ABOVE MINIMUM REQUIREMENTS, AS MAY BE NEEDED, TO
PROTECT ADJACENT PROPERTIES AND WATER QUALITY OF THE
RECEIVING DRAINAGE SYSTEM.
10.APPROVAL OF THIS PLAN IS FOR ESC ONLY. IT DOES NOT
CONSTITUTE AN APPROVAL OF STORM DRAINAGE DESIGN, SIZE NOR
LOCATION OF PIPES, RESTRICTORS, CHANNELS, OR STORMWATER
FACILITIES.
11.ANY DEWATERING SYSTEM NECESSARY FOR THE CONSTRUCTION OF
STORMWATER FACILITIES SHALL BE SUBMITTED TO THE CITY FOR
REVIEW AND APPROVAL.
12.ANY AREAS OF EXPOSED SOILS, INCLUDING ROADWAY
EMBANKMENTS, THAT WILL NOT BE DISTURBED FOR TWO DAYS DURING
THE WET SEASON (OCTOBER 1ST THROUGH APRIL 30TH) OR SEVEN
DAYS DURING THE DRY SEASON (MAY 1ST THROUGH SEPTEMBER 30TH)
SHALL BE IMMEDIATELY STABILIZED WITH THE APPROVED ESC
COVER METHODS (E.G., SEEDING, MULCHING, PLASTIC COVERING, ETC.)
IN CONFORMANCE WITH APPENDIX D OF THE RSWDM.
13.WET SEASON ESC REQUIREMENTS APPLY TO ALL CONSTRUCTION
SITES BETWEEN OCTOBER 1ST AND APRIL 30TH, UNLESS OTHERWISE
APPROVED BY THE CITY.
14.ANY AREA NEEDING ADDITIONAL ESC MEASURES, NOT REQUIRING
IMMEDIATE ATTENTION, SHALL BE ADDRESSED WITHIN SEVEN (7) DAYS.
15.THE ESC BMPS ON INACTIVE SITES SHALL BE INSPECTED AND
MAINTAINED AT A MINIMUM OF ONCE A MONTH OR WITHIN 24 HOURS
FOLLOWING A STORM EVENT. INSPECTION AND MAINTENANCE SHALL
OCCUR MORE FREQUENTLY AS REQUIRED BY THE CITY.
16.BEFORE COMMENCEMENT OF ANY CONSTRUCTION ACTIVITY, CATCH
BASIN INSERTS PER THE CITY STANDARD PLANS 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 INLET WILL BE CONVEYED TO A SEDIMENT POND OR TRAP.
ALL CATCH BASIN INSERTS SHALL BE PERIODICALLY INSPECTED AND
REPLACED AS NECESSARY TO ENSURE FULLY FUNCTIONING
CONDITION.
17.AT NO TIME SHALL SEDIMENT ACCUMULATION EXCEED 2/3 OF THE
CAPACITY OF THE CATCH BASIN SUMP. ALL CATCH BASINS AND
CONVEYANCE LINES SHALL BE CLEANED PRIOR TO PAVING. THE
CLEANING OPERATION SHALL NOT FLUSH SEDIMENT-LADEN WATER
INTO THE DOWNSTREAM SYSTEM.
18.ANY PERMANENT STORMWATER FACILITY USED AS A TEMPORARY
SETTLING BASIN SHALL BE MODIFIED WITH THE NECESSARY ESC BMPS
AND SHALL PROVIDE ADEQUATE STORAGE CAPACITY. IF THE
PERMANENT FACILITY IS TO FUNCTION ULTIMATELY AS AN INFILTRATION
SYSTEM, THE TEMPORARY FACILITY SHALL BE ROUGH GRADED SO THAT
THE BOTTOM AND SIDES ARE AT LEAST THREE FEET ABOVE THE FINAL
GRADE OF THE PERMANENT FACILITY.
19.AREAS DESIGNATED ON THE PLAN(S) CONTAINING EXISTING
STORMWATER FACILITIES OR ON-SITE BMPS (AMENDED SOILS,
BIORETENTION, PERMEABLE PAVEMENT, ETC.) SHALL BE CLEARLY
FENCED AND PROTECTED USING ESC BMPS TO AVOID SEDIMENTATION
AND COMPACTION DURING CONSTRUCTION.
20.PRIOR TO THE BEGINNING OF THE WET SEASON (OCTOBER 1ST), ALL
DISTURBED AREAS SHALL BE INSPECTED TO IDENTIFY WHICH ONES
SHALL BE SODDED OR SEEDED IN PREPARATION FOR THE WINTER
RAINS. DISTURBED AREAS SHALL BE SODDED OR SEEDED WITHIN ONE
WEEK OF THE BEGINNING OF THE WET SEASON. AN EXHIBIT OF
THOSE AREAS TO BE SODDED OR SEEDED AND THOSE AREAS TO
REMAIN UNCOVERED SHALL BE SUBMITTED TO THE CITY FOR REVIEW.
21.PRIOR TO FINAL CONSTRUCTION ACCEPTANCE, THE PROJECT SITE
SHALL BE STABILIZED TO PREVENT SEDIMENT-LADEN WATER FROM
LEAVING THE PROJECT SITE, ALL ESC BMPS SHALL BE REMOVED, AND
STORMWATER CONVEYANCE SYSTEMS, FACILITIES, AND ON-SITE BMPS
SHALL BE RESTORED TO THEIR FULLY FUNCTIONING
CONDITION. ALL DISTURBED AREAS OF THE PROJECT SITE SHALL BE
VEGETATED OR OTHERWISE PERMANENTLY STABILIZED. AT A MINIMUM,
DISTURBED AREAS SHALL BE SODDED OR SEEDED AND MULCHED TO
ENSURE THAT SUFFICIENT COVER WILL DEVELOP SHORTLY AFTER
FINAL APPROVAL. MULCH WITHOUT SEEDING IS ADEQUATE FOR SMALL
AREAS TO BE LANDSCAPED BEFORE OCTOBER 1ST.
22.ROCKERIES ARE CONSIDERED TO BE A METHOD OF BANK
STABILIZATION AND EROSION CONTROL. ROCKERIES SHALL NOT BE
CONSTRUCTED TO SERVE AS RETAINING WALLS. ALL ROCKERIES IN
CITY ROAD RIGHT-OF-WAY SHALL BE CONSTRUCTED IN ACCORDANCE
WITH CITY STANDARDS. ROCKERIES OUTSIDE OF ROAD RIGHT-OF-WAY
SHALL BE CONSTRUCTED IN ACCORDANCE WITH THE INTERNATIONAL
BUILDING CODE.
EROSION CONTROL (ESC) STANDARD PLAN NOTES
8
CITY OF
RENTON
IN COMPLIANCE WITH CITY OF RENTON STANDARDS
Civil Engineers
Structural Engineers
Landscape Architects
Community Planners
Natural Resource Ecologists
Land Surveyors
Neighbors
T A C O M A
2215 North 30th Street, Suite 300 Tacoma, WA 98403
253.383.2422TEL 253.383.2572FAX www.ahbl.comWEB
S E A T T L E
S P O K A N E T R I - C I T I E S
WALKER AUTO DEALERSHIP
EARLY CLEAR AND GRADE PLANS
AHBL JOB #2180100.10
9
Know what's below.
before you dig.Call
RTED-40-4018C:18004244LUA:18-000305PR:18000212R-40180
TESC NOTES AND DETAILS C3.2
9
CONSTRUCTION SEQUENCE
1.SCHEDULE AND ATTEND PRE-CONSTRUCTION MEETING WITH
STEMEN'S ENVIRONMENTAL, THE ENGINEER, OWNER'S
REPRESENTATIVE, GEOTECHNICAL ENGINEER, CESCL, AND
CITY INSPECTOR.
2.POST SIGN WITH NAME AND PHONE NUMBER OF ESC
SUPERVISOR (MAY BE CONSOLIDATED WITH THE REQUIRED
NOTICE OF CONSTRUCTION SIGN).
3.SECURE THE PROJECT SITE WITH SECURITY FENCING.
4.CHECK AND FIX EXISTING PERIMETER FABRIC FENCING.
5.INSTALL CATCH BASIN PROTECTION ALONG FRONTAGE.
6.MAINTAIN EXISTING AND PROVIDE NEW CONSTRUCTION
ENTRANCE(S).
7.DELIVER AND CONFIGURE STORMWATER STORAGE TANKS.
POTHOLE SIDE SEWER AND CONNECT TANKS FOR
DISCHARGE. SEWER DISCHARGE SHALL ADHERE TO THE
KING COUNTY SEWER DISCHARGE PERMIT.
8.GRADE AND STABILIZE ONSITE CONSTRUCTION ROADS IF
NECESSARY FOR TRUCK TRAFFIC.
9.CONSTRUCT SURFACE WATER CONTROLS (INTERCEPTOR
DIKES, PIPE SLOPE DRAINS, ETC.) SIMULTANEOUSLY WITH
CLEARING AND GRADING FOR PROJECT DEVELOPMENT.
10.MAINTAIN EROSION CONTROL MEASURES IN ACCORDANCE
WITH APPENDIX D OF THE 2017 CITY OF RENTON SURFACE
WATER DESIGN MANUAL (2017 RSWDM) AND
MANUFACTURER'S RECOMMENDATIONS.
11.RELOCATE EROSION CONTROL MEASURES OR INSTALL NEW
MEASURES SO THAT AS SITE CONDITIONS CHANGE THE
EROSION AND SEDIMENT CONTROL IS ALWAYS IN
ACCORDANCE WITH THE CITY'S EROSION AND SEDIMENT
CONTROL STANDARDS.
12.COVER ALL AREAS THAT WILL BE UNWORKED FOR MORE
THAN SEVEN DAYS DURING THE DRY SEASON OR TWO DAYS
DURING THE WET SEASON WITH STRAW, WOOD FIBER
MULCH, COMPOST, PLASTIC SHEETING, OR EQUIVALENT.
13.STABILIZE ALL AREAS THAT REACH FINAL GRADE WITHIN
SEVEN DAYS.
14.STABILIZE ANY AREAS TO REMAIN UNWORKED FOR MORE
THAN 30 DAYS. STABILIZE RECLAIMED AREAS WITH ROCK
SURFACING.
14. THE WETLAND BUFFER SHALL BE RESTORED IN ACCORDANCE
WITH THE LANDSCAPE PLANS.
15.UPON COMPLETION OF THE PROJECT, ALL DISTURBED
AREAS MUST BE STABILIZED AND BMPS REMOVED IF
APPROPRIATE.Q:\2018\2180100\10_CIV\CAD\_Fill and Grade\2180100-SH-TESC.dwg9
T EAST VALLEY ROADS.R. 167SW 34TH ST
Civil Engineers
Structural Engineers
Landscape Architects
Community Planners
Land Surveyors
Neighbors
WALKER DEALERSHIP
2180100.10
N
GRAPHIC SCALE
0 80 160
1" = 80 FEET
40
Q:\2018\2180100\10_CIV\CAD\EXHIBITS\20181005 - Temp Ponding.dwg
ESC Plan for Construction Stormwater Pollution Prevention
Walker Auto Dealership
2180100.10
Appendix B
Select King County Source Control BMPs
ESC Plan for Construction Stormwater Pollution Prevention
Walker Auto Dealership
2180100.10
Appendix C
Inspection and Maintenance Report Forms
ESC Plan for Construction Stormwater Pollution Prevention
Walker Auto Dealership
2180100.10
Appendix D
Geotechnical Report
Migizi Group, Inc., April 27, 2018
Geotechnical Engineering Report
Walker Renton Auto Dealership
3400 East Valley Road
Renton, Washington
P/N 302305-9067
April 27, 2018
prepared for:
HHJ Architects, PLLC
Attention: Roger Hansen
601 St Helens
Tacoma Washington 98402
prepared by:
Migizi Group, Inc.
PO Box 44840
Tacoma, Washington 98448
(253) 537-9400
MGI Project P1238-T18
i
TABLE OF CONTENTS
Page No.
1.0 SITE AND PROJECT DESCRIPTION .............................................................................................. 1
2.0 EXPLORATORY METHODS ............................................................................................................ 2
2.1 Auger Boring Procedures...................................................................................................... 3
3.0 SITE CONDITIONS ............................................................................................................................ 3
3.1 Surface Conditions ................................................................................................................. 3
3.2 Soil Conditions ....................................................................................................................... 4
3.3 Groundwater Conditions ...................................................................................................... 5
3.4 Seismic Conditions ................................................................................................................. 5
3.5 Liquefaction Potential ........................................................................................................... 5
3.6 Infiltration Conditions ........................................................................................................... 6
4.0 CONCLUSIONS AND RECOMMENDATIONS............................................................................ 6
4.1 Site Preparation ...................................................................................................................... 7
4.2 Augercast Piles ....................................................................................................................... 9
4.3 Slab-On-Grade-Floors .......................................................................................................... 11
4.4 Drainage Systems ................................................................................................................. 11
4.5 Asphalt Pavement ................................................................................................................ 12
4.6 Structural Fill ........................................................................................................................ 13
5.0 RECOMMENDED ADDITIONAL SERVICES ............................................................................. 14
6.0 CLOSURE ........................................................................................................................................... 15
List of Tables
Table 1. Approximate Locations and Depth of Explorations .............................................................................. 2
Table 2. Recommended Allowable Pile Capacities ............................................................................................... 9
List of Figures
Figure 1. Topographic and Location Map
Figure 2. Site and Exploration Plan
APPENDIX A
Soil Classification Chart and Key to Test Data .................................................................................................. A-1
Log of Auger Borings B-1 and B-2 ............................................................................................................. A-2…A-3
Page 1 of 15
MIGIZI GROUP, INC.
PO Box 44840 PHONE (253) 537-9400
Tacoma, Washington 98448 FAX (253) 537-9401
April 17, 2018
HHJ Architects, PLLC
601 St Helens
Tacoma, Washington 98402
Attention: Roger Hansen
Subject: Geotechnical Engineering Report
Walker Renton Auto Dealership
3400 East Valley Road
Renton, Washington
P/N 302305-9067
MGI Project P1238-T18
Dear Mr. Hansen:
Migizi Group, Inc. (MGI) is pleased to submit this report describing the results of our geotechnical
engineering evaluation of the proposed Walker Renton Auto Dealership development at 3400
East Valley Road in Renton, Washington.
This report has been prepared for the exclusive use of HHJ Architects, PLLC, and their
consultants, for specific application to this project, in accordance with generally accepted
geotechnical engineering practice.
1.0 SITE AND PROJECT DESCRIPTION
The project site consists of an irregularly-shaped, 5.65-acre, commercially-zoned parcel located
towards the south end of the city limits of Renton, Washington, as shown on the enclosed
Topographic and Location Map (Figure 1). The subject property is situated between East Valley
Road and SR-167 in a heavily developed commercial area. The project site has previously been
developed, being utilized as an auto junk yard. A 4,000-sf warehouse building and 1,160 sf
radiator shop are still present towards the northwest corner of the project area, as well as paved
parking facilities. The remainder of the site had been graded to accommodate storage of vehicles
and auto parts, though these have previously been removed from the site. During this initial
development of the site, the wetland area along the west side of SR-167 had been severely
damaged, and in many cases had been filled.
HHJ Architects, PLLC – Walker Renton Auto Dealership, 3400 E Valley Rd, Renton, WA April 27, 2018
Geotechnical Engineering Report P1238-T18
Migizi Group, Inc. Page 2 of 15
It is our understanding that improvement plans involve the demolition of existing site features
and the repurposing of the property as an auto dealership. This will involve the construction of
a new 50,000 to 60,000 sf two-story, wood-framed structure towards the center of the property, in
addition to extensive pavements surrounding this facility. The new structure will contain a
showroom/sales area, business offices, parts sales and storage, service and shop regions, storage
and other supportive areas. In addition to the aforementioned improvements, the subject
development will also entail the restoration of the existing wetland which was damaged by
previous actions at the east side of the site along SR-167, and the establishment and maintaining
of a new 75-foot buffer area from this wetland. Environmental cleanup will be performed in
conjunction with new construction as appropriate, based on recommendations provided by Kane
Environmental.
2.0 EXPLORATORY METHODS
We explored surface and subsurface conditions at the project site on March 16, 2018. Our
exploration and evaluation program comprised the following elements:
• Surface reconnaissance of the site;
• Two auger boring explorations (designated B-1 and B-2), advanced on March 16,
2016; and
• A review of published geologic and seismologic maps and literature.
Table 1 summarizes the approximate functional locations and termination depths of our
subsurface explorations, and Figure 2 depicts their approximate relative locations. The following
sections describe the procedures used for excavation of test pits.
TABLE 1
APPROXIMATE LOCATIONS AND DEPTHS OF EXPLORATIONS
Exploration Functional Location
Termination
Depth
(feet)
B-1
B-2
East end of proposed building footprint
Southwest corner of proposed building footprint
61½
51½
The specific number and locations of our explorations were selected in relation to the existing site
features, under the constraints of surface access, underground utility conflicts, and budget
considerations.
It should be realized that the explorations performed and utilized for this eva luation reveal
subsurface conditions only at discrete locations across the project site and that actual conditions
in other areas could vary. Furthermore, the nature and extent of any such variations would not
become evident until additional explorations are performed or until construction activities have
begun. If significant variations are observed at that time, we may need to modify our conclusions
and recommendations contained in this report to reflect the actual site conditions.
HHJ Architects, PLLC – Walker Renton Auto Dealership, 3400 E Valley Rd, Renton, WA April 27, 2018
Geotechnical Engineering Report P1238-T18
Migizi Group, Inc. Page 3 of 15
2.1 Auger Boring Procedures
Our exploratory borings were advanced through the soil with a hollow-stem auger, using a truck-
mounted drill rig, operated by an independent drilling firm working under subcontract to MGI.
An engineering geologist from our firm continuously observed the boring, logged the subsurface
conditions, and collected representative soil samples. All samples were stored in watertight
containers and later transported to a laboratory for further visual examination and testing. After
the borings were completed, the borehole was backfilled in accordance with state requirements.
Throughout the drilling operation, soil samples were obtained at 2½ to 5-foot depth intervals by
means of the Standard Penetration Test (SPT) per American Society for Testing and Materials
(ASTM:D-1586), or using a large split-spoon sampler. This testing and sampling procedure
consists of driving a standard 2-inch-outside-diameter steel split-spoon sampler 18 inches into
the soil with a 140-pound hammer free-falling 30 inches. The number of blows struck during the
final 12 inches is recorded on the boring log. If a total of 50 blows are struck within any 6 -inch
interval, the driving is stopped, and the blow count is recorded as 50 blows for the actual
penetration distance. The resulting blow count values indicate the relative density of granular
soils and the relative consistency of cohesive soils. The soils were classified visually in general
accordance with the system described in Figure A-1, which includes a key to our exploration logs.
Summary logs of our explorations are included as Figures A-2 and A-3.
The enclosed boring logs describe the vertical sequence of soils and materials encountered in the
borings, based primarily on our field classifications and supported by our subsequent laboratory
examination and testing. Where a soil contact was observed to be gradational, our logs indicate
the average contact depth. Where a soil type changed between sample intervals, we inferred the
contact depth. Our logs also graphically indicate the blow count, sample type, sample number,
and approximate depth of each soil sample obtained from the boring, as well as any laboratory
tests performed on these soil samples. If any groundwater was encountered in the borehole, the
approximate groundwater depth is depicted on the boring logs. Groundwater depth estimates
are typically based on the moisture content of soil samples, the wetted height on the drilling rods,
and the water level measured in the borehole after the auger has been extracted.
3.0 SITE CONDITIONS
The following sections present our observations, measurements, findings, and interpretations
regarding, surface, soil, groundwater, and infiltration conditions.
3.1 Surface Conditions
As previously indicated, the project site consists of an irregularly-shaped, 5.65-acre,
commercially-zoned parcel, located towards the south end of the city limits of Renton, between
East Valley Road and SR-167 in a heavily developed commercial area. The site is bound on the
north by East Valley RV & Boat Storage, on the south by the Brickman Group storage yard, on
the west by East Valley Road, and on the east by SR 167. The northwest corner of the project area
retains an existing 4,000-sf warehouse building, a 1,160-sf radiator shop, and asphalt pavement
parking facilities. The aforementioned structures were originally constructed in 1996. The
remainder of the site had been graded and resurfaced with recycled concrete, to serve as a storage
HHJ Architects, PLLC – Walker Renton Auto Dealership, 3400 E Valley Rd, Renton, WA April 27, 2018
Geotechnical Engineering Report P1238-T18
Migizi Group, Inc. Page 4 of 15
location for automobile parts and debris. The entirety of the site is enclosed by a chain-link fence,
with access to the interior being gained through a locked gate.
Topographically, the site is relatively level with minimal grade changes being observed over its
extent. Purportedly, the eastern margin of the site is a historic wetland region, which had been
infringed upon by past developments. This portion of the site served as part of the larger basin
for Panther Creek, which travels north and south of the project area along the east side of SR 167.
No vegetation was observed on site outside of scattered weeds which have taken root within the
existing gravel surfacing. No hydrological features were observed on site, such as seeps, springs,
ponds and streams. Scattered ponding was observed across the southwest portion of the site at
the time of our site visit. We believe that this is seasonal in nature, and not indicative of
hydrogeological conditions onsite.
3.2 Soil Conditions
We observed subsurface conditions through the advancement of two geotechnical borings within
the footprint of the 50,000 to 60,000-sf structure proposed towards the interior of the site. These
explorations extended 51½ to 61½ feet below existing grade, respectively, encountering relatively
consistent subgrade conditions. Approximately 5 feet of fill soils were observed at surface
elevations in both of our explorations, ranging in composition from recycled concrete to gravelly
silty sand. Both of these material types were encountered in a medium dense to dense in situ
condition. Underlying these fill soils, we encountered native, alluvial deposits. With depth,
alluvial deposits encountered onsite exhibited alternating layers of poorly consolidated
fine-grained soils, and moderately consolidated granular soils; highlighting the shifting, localized
depositional environment across the project area. The uppermost fine-grained zone, observed
immediately below existing fill material, contained a significant organic component. Both of our
explorations encountered, below a depth of ± 31 feet, through their respective termination depths,
moderately dense, fine silty sand.
In the Geologic Map of the Tacoma 1:100,000-scale Quadrangle, as prepared by the Washington State
Department of Natural Resources Division of Geology and Earth Resources (WSDNR) (2015), the
project site is mapped as containing Qp, or peat, which directly overlies Qa, or Quaternary
Alluvium. Peat, as per this publication, is described as loose, locally very soft and wet, organic
and organic rich sediment, including muck, silt and clay. Alluvium, as it pertains to the
geographic setting of the project area, refers to sedimentary deposits associated with the flood
plains of the Duwamish/Green Rivers, and are typically comprised of loose, stratified to
massively bedded fluvial silt, sand, and gravel that is typically, well rounded and moderately to
well sorted and locally includes sandy to silty estuarine deposits. Our field observations and
subsurface explorations generally conform with the geologic classification of the site performed
by the WSDNR.
The enclosed exploration logs (Appendix A) provide a detailed description of the soil strata
encountered in our subsurface explorations.
HHJ Architects, PLLC – Walker Renton Auto Dealership, 3400 E Valley Rd, Renton, WA April 27, 2018
Geotechnical Engineering Report P1238-T18
Migizi Group, Inc. Page 5 of 15
3.3 Groundwater Conditions
At the time of our reconnaissance and subsurface explorations (March 16, 2018), we encountered
groundwater seepage at a depth which ranged from 8 to 15 feet below existing grade .
Groundwater levels were generally higher towards the southwest corner of the project area,
where significant surficial ponding was observed at the time of our site visit. Given the fact that
our explorations were performed within what is generally considered the rainy season (October
1st through April 30th), we do not anticipate that groundwater will rise much higher than that
which we observed. Groundwater levels will fluctuate with localized geology and precipitation.
3.4 Seismic Conditions
Based on our analysis of subsurface exploration logs and our review of published geologic maps,
we interpret the onsite soil conditions to generally correspond with site class E, as defined by
Table 20.3-1 in ASCE 7, per the 2015 International Building Code (IBC).
Using 2015 IBC information on the USGS Design Summary Report website, Risk Category I/II/III
seismic parameters for the site are as follows:
Ss = 1.418 g SMS = 1.276 g SDS = 0.851 g
S1 = 0.528 g SM1 = 1.266 g SD1 = 0.844 g
Using the 2015 IBC information, MCER Response Spectrum Graph on the USGS Design Summary
Report website, Risk Category I/II/III, Sa at a period of 0.2 seconds is 1.28 g and Sa at a period of
1.0 seconds is 1.27 g.
The Design Response Spectrum Graph from the same website, using the same IBC information
and Risk Category, Sa at a period of 0.2 seconds is 0.85 g and Sa at a period of 1.0 seconds is 0.84 g.
3.5 Liquefaction Potential
Liquefaction is a sudden increase in pore water pressure and a sudden loss of soil shear strength
caused by shear strains, as could result from an earthquake. Research has shown that saturated,
loose, fine to medium sands with a fines (silt and clay) content less than about 20 percent are most
susceptible to liquefaction. Subsurface explorations performed for this project indicate that the
site is underlain by poorly consolidated alluvial soils, ranging in composition from a fine sand
with silt to sandy silt; with intermittent layers or lenses of peat. Given the geologic/hydrogeolgic
conditions of the project area, we interpret this site as having a moderate susceptibility to
liquefaction. In Section 4.2 of this report, we provide recommendations for the preparation of the
foundation subgrade which would help mitigate much of this risk, however, during a large-scale
seismic event, some degree of liquefaction and related post-construction settlement should be
anticipated. We recommend that the structure be designed to prevent catastrophic collapse
during a seismic event.
HHJ Architects, PLLC – Walker Renton Auto Dealership, 3400 E Valley Rd, Renton, WA April 27, 2018
Geotechnical Engineering Report P1238-T18
Migizi Group, Inc. Page 6 of 15
3.6 Infiltration Conditions
As indicated in the Soil and Groundwater Conditions sections of this report, the site is underlain
by fill material and poorly-drained, slowly permeable, alluvial soils, with a shallow groundwater
table. As such, we do not interpret infiltration as being feasible for this project, and recommend
that site produced stormwater be diverted to an existing storm system, managed through
detention, or other appropriate means.
4.0 CONCLUSIONS AND RECOMMENDATIONS
It is our understanding that improvement plans involve the demolition of existing site features
and the repurposing of the property as an auto dealership. This will involve the constructi on of
a new 50,000 to 60,000 sf two-story, wood-framed structure towards the center of the property, in
addition to extensive pavements surrounding this facility. The new structure will contain a
showroom/sales area, business offices, parts sales and storage, service and shop regions, storage
and other supportive areas. In addition to the aforementioned improvements, the subject
development will also entail the restoration of the existing wetland which was damaged by
previous actions at the east side of the site along SR-167, and the establishment and maintaining
of a new 75-foot buffer area from this wetland. Environmental cleanup will be performed in
conjunction with new construction as appropriate, based on recommendations provided by Kane
Environmental. We offer the following recommendations:
• Feasibility: Based on our field explorations, research, and evaluations, the
proposed structures and pavements appear feasible from a geotechnical
standpoint.
• Foundation Options: In order to address soil and liquefaction conditions within
the proposed expansion area and limit settlement of the addition and new
settlement of the existing structure, we recommend that all foundation elements
be supported by augercast piles. Recommendations for augercast pile
foundations are presented in Section 4.2.
• Floor Options: In our opinion, soil-supported slab-on-grade floors can be used if
the subgrades are properly prepared. However, there is a potential that
liquefaction settlement of the underlying site soils could cause cracking and
damage to soil-supported slab-on-grade floors during the design earthquake. If
the potential for damage is not acceptable, we recommend that floor slabs be
structurally supported.
If used, soil supported floor sections should bear on medium dense or denser
native soils or on properly compacted structural fill that extends down to medium
dense or denser native soil. Recommendations for slab-on-grade floors are
included in Section 4.3. Fill underlying floor slabs should be compacted to
95 percent (ASTM:D-1557).
• Pavement: We recommend a conventional pavement section comprised of asphalt
concrete over crushed rock base course over properly prepared subgrade. Because
soft soils immediately underlie proposed pavements, subgrade preparation
HHJ Architects, PLLC – Walker Renton Auto Dealership, 3400 E Valley Rd, Renton, WA April 27, 2018
Geotechnical Engineering Report P1238-T18
Migizi Group, Inc. Page 7 of 15
generally should consist of an over-excavation of two feet, compaction of exposed
subgrade soils, then replacement with a suitable structural fill. Compaction
should be done in accordance with the structural fill recommendations presented
in Section 4.6.
All soil subgrades below 24 inches should be thoroughly compacted, then proof-
rolled with a loaded dump truck or heavy compactor. Any localized zones of
yielding subgrade disclosed during this proof-rolling operation should be over
excavated to an additional maximum depth of 12 inches and replaced with a
suitable structural fill material.
The following sections of this report present our specific geotechnical conclusions and
recommendations concerning site preparation, spread footings, slab-on-grade floors, pavement,
and structural fill. The Washington State Department of Transportation (WSDOT) Standard
Specifications and Standard Plans cited herein refer to WSDOT publications M41-10, Standard
Specifications for Road, Bridge, and Municipal Construction, and M21 -01, Standard Plans for
Road, Bridge, and Municipal Construction, respectively.
4.1 Site Preparation
Preparation of the project site should involve erosion control, temporary drainage, clearing,
stripping, excavations, cutting, subgrade compaction, and filling.
Erosion Control: Before new construction begins, an appropriate erosion control system should
be installed. This system should collect and filter all surface water runoff through silt fencing.
We anticipate a system of berms and drainage ditches around construction areas will provide an
adequate collection system. Silt fencing fabric should meet the requirements of WSDOT Standard
Specification 9-33.2 Table 3. In addition, silt fencing should embed a minimum of 6 inches below
existing grade. An erosion control system requires occasional observation and maintenance.
Specifically, holes in the filter and areas where the filter has shifted above ground surface should
be replaced or repaired as soon as they are identified.
Temporary Drainage: We recommend intercepting and diverting any potential sources of surface
or near-surface water within the construction zones before stripping begins. Because the selection
of an appropriate drainage system will depend on the water quantity, season, weather conditions,
construction sequence, and contractor's methods, final decisions regarding drainage systems are
best made in the field at the time of construction. Based on our current understanding of the
construction plans, surface and subsurface conditions, we anticipate that curbs, berms, or ditches
placed around the work areas will adequately intercept surface water runoff.
Clearing and Stripping: After surface and near-surface water sources have been controlled, sod,
topsoil, and root-rich soil should be stripped from the site. Our explorations and field
observations indicate that no significant organic horizon is observed at surface elevations across
the project area.
HHJ Architects, PLLC – Walker Renton Auto Dealership, 3400 E Valley Rd, Renton, WA April 27, 2018
Geotechnical Engineering Report P1238-T18
Migizi Group, Inc. Page 8 of 15
Site Excavations: Based on our explorations, we expect that excavations will encounter
moderately consolidated fill soils at shallow elevations, and poorly consolidated alluvial soils
immediately beneath this material, both of which can be readily excavated using standard
excavation equipment.
Dewatering: Groundwater seepage was encountered in both of our subsurface explorations at a
depth of 8 to 15 feet below existing grade, with higher groundwater tables being observed across
regions exhibiting surficial ponding. If groundwater is encountered in excavations above the
water table, or slightly below, we anticipate that an internal system of ditches, sumpholes, and
pumps will be adequate to temporarily dewater shallow excavations. For excavations
significantly below the water table, we anticipate that expensive dewatering equipment, such as
well points, will be required to temporarily dewater excavations.
Temporary Cut Slopes: All temporary soil slopes associated with site cutting or excavations
should be adequately inclined to prevent sloughing and collapse. Temporary cut slopes in site
soils should be no steeper than 1½H:1V and should conform to Washington Industrial Safety and
Health Act (WISHA) regulations.
Subgrade Compaction: Exposed subgrades for the foundations of the planned structures should
be compacted to a firm, unyielding state before new concrete or fill soils are placed. Any localized
zones of looser granular soils observed within a subgrade should be compacted to a density
commensurate with the surrounding soils. In contrast, any organic, soft, or pumping soils
observed within a subgrade should be over-excavated and replaced with a suitable structural fill
material.
Site Filling: Our conclusions regarding the reuse of onsite soils and our comments regarding wet-
weather filling are presented subsequently. Regardless of soil type, all fill should be placed and
compacted according to our recommendations presented in the Structural Fill section of this
report. Specifically, building pad fill soil should be compacted to a uniform density of at least
95 percent (based on ASTM:D-1557).
Onsite Soils: We offer the following evaluation of these onsite soils in relation to potential use as
structural fill:
• Surficial Organic Soil and Organic-Rich Topsoil: Where encountered, surficial
organic soils, like duff, topsoil, root-rich soil, and organic-rich fill soils are not
suitable for use as structural fill under any circumstances, due to high organic
content. Consequently, this material can be used only for non-structural purposes,
such as in landscaping areas.
• Existing Fill Material: As described in the Soil Conditions section of this report, the
uppermost 5-feet of soils encountered onsite are comprised of existing fill material
placed during the original site development. This material ranged in composition
between recycled concrete and gravelly silty sand. These materials should be
considered moderately sensitive, and reuse should be confined to periods of
extended dry weather.
HHJ Architects, PLLC – Walker Renton Auto Dealership, 3400 E Valley Rd, Renton, WA April 27, 2018
Geotechnical Engineering Report P1238-T18
Migizi Group, Inc. Page 9 of 15
• Alluvial Soils: Underlying existing fill material, we encountered native alluvial
soils exhibiting alternating layers of poorly consolidated fine -grained soils and
moderately consolidated granular soils. The uppermost fine -grained layer is the
only native soils which could be feasibly reused as structural fill throughout the
course of this project. This soil group contains a high organic content, is extremely
moisture sensitive, and is generally encountered in an over-saturated condition.
Reuse of this material should be limited to landscaping areas.
Permanent Slopes: All permanent cut slopes and fill slopes should be adequately inclined to
reduce long-term raveling, sloughing, and erosion. We generally recommend that no permanent
slopes be steeper than 2H:1V. For all soil types, the use of flatter slopes (such as 2½H:1V) would
further reduce long-term erosion and facilitate revegetation.
Slope Protection: We recommend that a permanent berm, swale, or curb be constructed along
the top edge of all permanent slopes to intercept surface flow. Also, a hardy vegetative
groundcover should be established as soon as feasible, to further protect the slopes from runoff
water erosion. Alternatively, permanent slopes could be armored with quarry spalls or a
geosynthetic erosion mat.
4.2 Augercast Piles
Based on the soil conditions discussed above, we recommend that the new building be supported
on augercast piles installed to a depth of 55 feet below the existing ground surface in the medium
dense silty sands. The following table provides estimated allowable design capacities for 14-inch,
16-inch, and 18-inch diameter augercast concrete pilings installed to the aforementioned
embedment depth:
TABLE 2
RECOMMENDED ALLOWABLE PILE CAPACITIES
14-INCH, 16-INCH AND 18-INCH DIAMETER AUGERCAST CONCRETE PILES
Pile Diameter
(inches)
Depth Below
Existing Ground
Surface
(feet)
Downward Capacity
(tons)
Uplift Capacity
(tons)
14 55 66 26
16 55 80 30
18 55 98 34
The allowable pile capacities presented above apply to all long-term live and dead loads and may
be increased by one-third when considering short-term loads such as wind or seismic influence.
The allowable pile capacities are based on the strength of the supporting soils for the penetrations
indicated and include a factor of safety of at least 2. The allowable uplift capacities indicated for
augercast piles may be used provided that a reinforcing bar is installed the entire length of the
pile. This bar should be centered in the pile.
HHJ Architects, PLLC – Walker Renton Auto Dealership, 3400 E Valley Rd, Renton, WA April 27, 2018
Geotechnical Engineering Report P1238-T18
Migizi Group, Inc. Page 10 of 15
Static pile settlements are expected to be essentially elastic in nature and occur as loads are applied.
Total static settlement of piles constructed as recommended are not expected to exceed 1 inch, while
differential static settlements between comparably loaded piles are not expected to exceed about
50 percent of this value.
The pile capacities provided above apply to single piles. If piles within groups are spaced at least
three pile diameters on center, no reduction for pile group action need be made. The structural
characteristics of the pile materials and allowable internal stresses may impose more stringent
limitations and should be evaluated by the structural engineer.
Lateral loadings due to wind or seismic forces can be resisted by uplift or lateral loading on the
piles, or lateral soil resistance of the pile cap. The manner in which these loads are transferred into
the piles will be a function of the design of the foundation system. Passive soil resistance of the pile
cap may be computed using an equivalent fluid density of 220 pcf (pounds per cubic foot) for a
level backfill surface, provided the backfill around the pile cap is compacted to at least 95 percent
of maximum dry density per American Society for Testing and Materials (ASTM) D-1557. This
value incorporates a factor of safety of about 1.5.
Lateral capacities for augercast piling are dependent upon the characteristics of the reinforcing
steel and the coefficient of subgrade reaction for the surrounding soils. We recommend that the
pile stiffness, T, be computed using the formula T = (EI/f)1/5 where E equals the pile modulus of
elasticity, I equals the pile moment of inertia, and f equals the soil coefficient of subgrade reaction.
A value of 6 tcf (tons per cubic foot) should be used for f. For the recommended penetration, the
maximum moment for piles fixed against rotation at the ground surface will occur at a depth
equal to about 1.8 T and the magnitude of this moment, M, can be computed using the formula
M = 0.25 PT where P is the lateral force applied at the ground surface. The moment will decrease
to zero at a depth of about 4.5 T. The maximum pile deflection at the ground surface can be
computed using the formula D = 0.93 (PT3/EI).
Pile Installation: Augercast (cast-in-place) concrete piles should be installed using a continuous-
flight, hollow-stem auger. As is common practice, the pile grout would be pumped under
pressure through the hollow-stem as the auger is withdrawn. Reinforcing steel for bending and
uplift would be placed in the fresh grout column immediately after withdrawal of the auger.
No direct information regarding the capacity of augercast piles (e.g., driving resistance data) is
obtained while this type of pile is being installed. Therefore, it is particularly important that the
installation of augercast piles be carefully monitored by a qualified individual working under the
direct supervision of a geotechnical engineer.
It should be noted that the recommended pile penetration and allowable capacities presented above
assumed uniform soil conditions. There may be unexpected variations in the depth and
characteristics of the supporting soils across the site.
HHJ Architects, PLLC – Walker Renton Auto Dealership, 3400 E Valley Rd, Renton, WA April 27, 2018
Geotechnical Engineering Report P1238-T18
Migizi Group, Inc. Page 11 of 15
Accordingly, we recommend that pile installation be monitored by a member of our staff who
will observe installation procedures and evaluate the adequacy of individual pile installations.
4.3 Slab-On-Grade Floors
In our opinion, soil-supported slab-on-grade floors can be used if the subgrades are properly
prepared. However, there is a potential that liquefaction settlement of the underlying site soils
could cause cracking and damage to soil-supported slab-on-grade floors during the design
earthquake. If the potential for damage is not acceptable, we recommend that floor slabs be
structurally supported.
We offer the following comments and recommendations concerning soil-supported slab-on-
grade floors.
Floor Subbase: We recommend over-excavation of slab-on-grade floor subgrades to a minimum
depth of 2 feet, then placement of properly compacted structural fill as a floor subbase. If floor
construction occurs during wet conditions, it is likely that a geotextile fabric, placed between the
structural fill floor subbase and native soils, will be necessary.
All subbase fill should be compacted to a density of at least 95 percent (based on ASTM:D-1557).
Capillary Break and Vapor Barrier: To retard the upward wicking of moisture beneath the floor
slab, we recommend that a capillary break be placed over the subgrade. Ideally, this capillary
break would consist of a 4-inch-thick layer of pea gravel or other clean, uniform, well-rounded
gravel, such as “Gravel Backfill for Drains” per WSDOT Standard Specification 9-03.12(4), but
clean angular gravel can be used if it adequately prevents capillary wicking. In addition, a layer
of plastic sheeting (such as Crosstuff, Visqueen, or Moistop) should be placed over the capillary
break to serve as a vapor barrier. During subsequent casting of the concrete slab, the contractor
should exercise care to avoid puncturing this vapor barrier.
Vertical Deflections: Due to elastic compression of subgrades, soil-supported slab-on-grade
floors can deflect downwards when vertical loads are applied. In our opinion, a subgrade
reaction modulus of 140 pounds per cubic inch can be used to estimate such deflections.
4.4 Drainage Systems
In our opinion, the proposed expansion area should be provided with a permanent drainage
system to reduce the risk of future moisture problems. We offer the following recommendations
and comments for drainage design and construction purposes.
Perimeter Drains: We recommend that the structure be encircled with a perimeter drain system
to collect seepage water. This drain should consist of a 4-inch-diameter perforated pipe within
an envelope of pea gravel or washed rock, extending at least 6 inches on all sides of the pipe, and
the gravel envelope should be wrapped with filter fabric to reduce the migration of fines from
the surrounding soils. Ideally, the drain invert would be installed no more than 8 inches above
the base of the perimeter footings.
HHJ Architects, PLLC – Walker Renton Auto Dealership, 3400 E Valley Rd, Renton, WA April 27, 2018
Geotechnical Engineering Report P1238-T18
Migizi Group, Inc. Page 12 of 15
Subfloor Drains: We recommend that subfloor drains be included beneath the new building.
These subfloor drains should consist of 4-inch-diameter perforated pipes surrounded by at least
6 inches of pea gravel and enveloped with filter fabric. A pattern of parallel pipes spaced no more
than 20 feet apart and having inverts located about 12 inches below the capillary break layer
would be appropriate, in our opinion.
Discharge Considerations: If possible, all perimeter drains should discharge to a sewer system
or other suitable location by gravity flow. Check valves should be installed along any drainpipes
that discharge to a sewer system to prevent sewage backflow into the drain system. If gravity
flow is not feasible, a pump system is recommended to discharge any water that enters the
drainage system.
Runoff Water: Roof-runoff and surface-runoff water should not discharge into the perimeter
drain system. Instead, these sources should discharge into separate tightline pipes and be routed
away from the building to a storm drain or other appropriate location.
Grading and Capping: Final site grades should slope downward away from the buildings so that
runoff water will flow by gravity to suitable collection points, rather than ponding near the
building. Ideally, the area surrounding the building would be capped with concrete, asphalt, or
low-permeability (silty) soils to minimize or preclude surface-water infiltration.
4.5 Asphalt Pavement
Since asphalt pavements will be expanded during the course of the proposed development, we
offer the following comments and recommendations for pavement design and construction.
Subgrade Preparation: After removal of any organics underlying pavements, we recommend a
conventional pavement section comprised of an asphalt concrete pavement over a crushed rock
base course over a properly prepared (compacted) subgrade or a granular subbase. Given the
relative loose/soft soil conditions observed across the project area, we recommend the over-
excavation of 24 inches of the existing subgrade material underlying the new pavement sections,
and replacement with a suitable structural fill subbase. Given the extent of the proposed paving
operation and corresponding earthwork activities, we recommend limiting the subgrade
preparation to times of dry weather.
All soil subgrades below 24 inches should be thoroughly compacted, then proof-rolled with a
loaded dump truck or heavy compactor. Any localized zones of yielding subgrade disclosed
during this proof-rolling operation should be over excavated to an additional maximum depth of
12 inches and replaced with a suitable structural fill material. All structural fill should be
compacted according to our recommendations given in the Structural Fill section. Specifically,
the upper 2 feet of soils underlying pavement section should be compacted to at least 95 percent
(based on ASTM D-1557), and all soils below 2 feet should be compacted to at least 90 percent.
Pavement Materials: For the base course, we recommend using imported crushed rock, such as
"Crushed Surfacing Top Course” per WSDOT Standard Specification 9-03.9(3). If a subbase
HHJ Architects, PLLC – Walker Renton Auto Dealership, 3400 E Valley Rd, Renton, WA April 27, 2018
Geotechnical Engineering Report P1238-T18
Migizi Group, Inc. Page 13 of 15
course is needed, we recommend using imported, clean, well-graded sand and gravel such as
“Ballast” or “Gravel Borrow” per WSDOT Standard Specifications 9-03.9(1) and 9-03.14,
respectively.
Conventional Asphalt Sections: A conventional pavement section typically comprises an asphalt
concrete pavement over a crushed rock base course. We recommend using the following
conventional pavement sections:
Minimum Thickness
Pavement Course Automobile Parking
Area Driveways Areas Subject to
Frequent Truck Traffic
Asphalt Concrete Pavement 2 inches 3 inches 4 inches
Crushed Rock Base 4 inches 6 inches 6 inches
Granular Fill Subbase (if needed) 12 inches 24 inches 24 inches
Compaction and Observation: All subbase and base course material should be compacted to at
least 95 percent of the Modified Proctor maximum dry density (ASTM D-1557), and all asphalt
concrete should be compacted to at least 92 percent of the Rice value (ASTM D-2041). We
recommend that an MGI representative be retained to observe the compaction of each course
before any overlying layer is placed. For the subbase and pavement course, compaction is best
observed by means of frequent density testing. For the base course, methodology observations
and hand-probing are more appropriate than density testing.
Pavement Life and Maintenance: No asphalt pavement is maintenance-free. The above described
pavement sections present our minimum recommendations for an average level of performan ce
during a 20-year design life, therefore, an average level of maintenance will likely be required.
Furthermore, a 20-year pavement life typically assumes that an overlay will be placed after about
10 years. Thicker asphalt and/or thicker base and subbase courses would offer better long-term
performance, but would cost more initially; thinner courses would be more susceptible to
“alligator” cracking and other failure modes. As such, pavement design can be considered a
compromise between a high initial cost and low maintenance costs versus a low initial cost and
higher maintenance costs.
4.6 Structural Fill
The term "structural fill" refers to any material placed under foundations, retaining walls, slab -
on-grade floors, sidewalks, pavements, and other structures. Our comments, conclusions, and
recommendations concerning structural fill are presented in the following paragraphs.
Materials: Typical structural fill materials include clean sand, gravel, pea gravel, washed rock,
crushed rock, well-graded mixtures of sand and gravel (commonly called "gravel borrow" or "pit-
run"), and miscellaneous mixtures of silt, sand, and gravel. Recycled asphalt, concrete, and glass,
which are derived from pulverizing the parent materials, are also potentially useful as structural
fill in certain applications. Utilizing recycled content may require approval from the Tacoma
Pierce County Health Department for placement in an aquifer recharge area. Soils used for
HHJ Architects, PLLC – Walker Renton Auto Dealership, 3400 E Valley Rd, Renton, WA April 27, 2018
Geotechnical Engineering Report P1238-T18
Migizi Group, Inc. Page 14 of 15
structural fill should not contain any organic matter or debris, nor any individual particles greater
than about 6 inches in diameter.
Fill Placement: Clean sand, gravel, crushed rock, soil mixtures, and recycled materials should be
placed in horizontal lifts not exceeding 8 inches in loose thickness, and each lift should be
thoroughly compacted with a mechanical compactor.
Compaction Criteria: Using the Modified Proctor test (ASTM:D-1557) as a standard, we
recommend that structural fill used for various onsite applications be compacted to the following
minimum densities:
Fill Application Minimum Compaction
Slab-on-grade floor subgrade (upper 2 feet)
Slab-on-grade floor subgrade (below 2 feet)
Asphaltic pavement base and subbase
Asphaltic pavement subgrade (upper 2 feet)
Asphaltic pavement subgrade (below 2 feet)
95 percent
90 percent
95 percent
95 percent
90 percent
Subgrade Observation and Compaction Testing: Regardless of material or location, all structural
fill should be placed over firm, unyielding subgrades prepared in accordance with the Site
Preparation section of this report. The condition of all subgrades should be observed by
geotechnical personnel before filling or construction begins. Also, fill soil compaction should be
verified by means of in-place density tests performed during fill placement so that adequacy of
soil compaction efforts may be evaluated as earthwork progresses.
Soil Moisture Considerations: The suitability of soils used for structural fill depends primarily
on their grain-size distribution and moisture content when they are placed. As the "fines" content
(that soil fraction passing the U.S. No. 200 Sieve) increases, soils become more sensitive t o small
changes in moisture content. Soils containing more than about 5 percent fines (by weight) cannot
be consistently compacted to a firm, unyielding condition when the moisture content is more than
2 percentage points above or below optimum. For fill placement during wet-weather site work,
we recommend using "clean" fill, which refers to soils that have a fines content of 5 percent or less
(by weight) based on the soil fraction passing the U.S. No. 4 Sieve.
5.0 RECOMMENDED ADDITIONAL SERVICES
Because the future performance and integrity of the structural elements will depend largely on
proper site preparation, drainage, fill placement, and construction procedures, monitoring and
testing by experienced geotechnical personnel should be considered an integral part of the
construction process. Consequently, we recommend that MGI be retained to provide the
following post-report services:
• Review all construction plans and specifications to verify that our design criteria
presented in this report have been properly integrated into the design;
• Prepare a letter summarizing all review comments (if required);
APPROXIMATE SITE
LOCATION
P.O. Box 44840
Tacoma, WA 98448
Location Job Number Figure
DateTitle
3400 East Valley Road
Renton, WA
P/N 302305-9067
Topographic and Location Map
1
04/06/18
P1238-T18
APPENDIX A
SOIL CLASSIFICATION CHART AND
KEY TO TEST DATA
LOG OF AUGER BORINGS
CLAYEY GRAVELS, POORLY GRADED GRAVEL-SAND-CLAY
MIXTURES
SILTS AND CLAYSCOARSE GRAINED SOILSMore than Half > #200 sieveLIQUID LIMIT LESS THAN 50
LIQUID LIMIT GREATER THAN 50
CLEAN GRAVELS
WITH LITTLE OR
NO FINES
GRAVELS WITH
OVER 15% FINES
CLEAN SANDS
WITH LITTLE
OR NO FINES
MORE THAN HALF
COARSE FRACTION
IS SMALLER THAN
NO. 4 SIEVE
MORE THAN HALF
COARSE FRACTION
IS LARGER THAN
NO. 4 SIEVE
INORGANIC SILTS, MICACEOUS OR DIATOMACIOUS FINE
SANDY OR SILTY SOILS, ELASTIC SILTS
ORGANIC CLAYS AND ORGANIC SILTY CLAYS OF LOW
PLASTICITY
OH
INORGANIC SILTS AND VERY FINE SANDS, ROCK FLOUR,
SILTY OR CLAYEY FINE SANDS, OR CLAYEY SILTS WITH
SLIGHT PLASTICITY
CH
SILTY GRAVELS, POORLY GRADED GRAVEL-SAND-SILT
MIXTURES
SANDS
SILTS AND CLAYS
Figure A-1
INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY,
GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS,
LEAN CLAYS
E3RA
R-Value
Sieve Analysis
Swell Test
Cyclic Triaxial
Unconsolidated Undrained Triaxial
Torvane Shear
Unconfined Compression
(Shear Strength, ksf)
Wash Analysis
(with % Passing No. 200 Sieve)
Water Level at Time of Drilling
Water Level after Drilling(with date measured)
RV
SA
SW
TC
TX
TV
UC
(1.2)
WA
(20)
Modified California
Split Spoon
Pushed Shelby Tube
Auger Cuttings
Grab Sample
Sample Attempt with No Recovery
Chemical Analysis
Consolidation
Compaction
Direct Shear
Permeability
Pocket Penetrometer
CA
CN
CP
DS
PM
PP
PtHIGHLY ORGANIC SOILS
TYPICAL NAMES
GRAVELS
ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY,
ORGANIC SILTS
WELL GRADED GRAVELS, GRAVEL-SAND MIXTURES
MAJOR DIVISIONS
PEAT AND OTHER HIGHLY ORGANIC SOILS
WELL GRADED SANDS, GRAVELLY SANDS
POORLY GRADED SANDS, GRAVELLY SANDS
SILTY SANDS, POOORLY GRADED SAND-SILT MIXTURES
CLAYEY SANDS, POORLY GRADED SAND-CLAY MIXTURES
POORLY GRADED GRAVELS, GRAVEL-SAND MIXTURES
SOIL CLASSIFICATION CHART AND KEY TO TEST DATA
GW
GP
GM
GC
SW
SP
SM
SC
ML
FINE GRAINED SOILSMore than Half < #200 sieveLGD A NNNN02 GINT US LAB.GPJ 11/4/05INORGANIC CLAYS OF HIGH PLASTICITY, FAT CLAYS
CL
OL
MH
SANDS WITH
OVER 15% FINES
SS
S-1
SS
S-2
SS
S-3
SS
S-4
SS
S-5
SS
S-6
SS
S-7
SS
S-8
6
6
12
12
12
18
18
18
11-19-12
(31)
6-3-6
(9)
3-3-4
(7)
1-2-2
(4)
2-1-2
(3)
2-5-6
(11)
2-3-12
(15)
4-1-1
(2)
SM
ML
SM
OH
SM
SP
ML
2.0
5.5
7.0
9.0
13.0
17.5
31.0
Recycled Concrete
(SM) Gray/brown silty sand with gravel (dense, damp) (Fill)
(ML) Gray/brown silt with some organics (stiff, moist) (Alluvium)
(SM) Gray silty sand with some gravel (loose, wet) (Alluvium)
(OH) Gray organic silt (soft, wet) (Alluvium)
(SM) Gray fine silty sand (very loose, wet) (Alluvium)
(SP) Black fine to coarse sand (medium dense, wet) (Alluvium)
With interbeds of silty sand
(ML) Gray silt (soft, wet) (Alluvium)
NOTES
LOGGED BY ZLL
DRILLING METHOD Truck Mounted Drill Rig
DRILLING CONTRACTOR Holocene GROUND WATER LEVELS:
CHECKED BY JEB
DATE STARTED 3/16/18 COMPLETED 3/16/18
AT TIME OF DRILLING 15.00 ft
AT END OF DRILLING ---
AFTER DRILLING ---
HOLE SIZE 4.25" HSAGROUND ELEVATION
SAMPLE TYPENUMBERDEPTH(ft)0
5
10
15
20
25
30
35
(Continued Next Page)
PAGE 1 OF 2
Figure A-2
BORING NUMBER B-1
CLIENT HHJ Architects, PLLC
PROJECT NUMBER P1238-T18
PROJECT NAME Walker Renton Auto Dealership Geotech Report
PROJECT LOCATION 3400 East Valley Road, Renton, WA
COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 4/5/18 15:42 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1238-T18\P1238-T18 BORING LOGS.GPJMigizi Group, Inc.
PO Box 44840
Tacoma, WA 98448
Telephone: 253-537-9400
Fax: 253-537-9401
RECOVERY (in)(RQD)BLOWCOUNTS(N VALUE)U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION
SS
S-9
SS
S-10
SS
S-11
SS
S-12
SS
S-13
SS
S-14
18
18
18
18
18
18
1-2-2
(4)
0-4-6
(10)
3-5-5
(10)
0-4-8
(12)
10-8-10
(18)
3-4-5
(9)
ML
SM
40.5
61.5
(ML) Gray silt (soft, wet) (Alluvium) (continued)
(SM) Gray fine silty sand (medium dense, wet) (Alluvium)
Grades to loose
Bottom of borehole at 61.5 feet.SAMPLE TYPENUMBERDEPTH(ft)35
40
45
50
55
60
PAGE 2 OF 2
Figure A-2
BORING NUMBER B-1
CLIENT HHJ Architects, PLLC
PROJECT NUMBER P1238-T18
PROJECT NAME Walker Renton Auto Dealership Geotech Report
PROJECT LOCATION 3400 East Valley Road, Renton, WA
COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 4/5/18 15:42 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1238-T18\P1238-T18 BORING LOGS.GPJMigizi Group, Inc.
PO Box 44840
Tacoma, WA 98448
Telephone: 253-537-9400
Fax: 253-537-9401
RECOVERY (in)(RQD)BLOWCOUNTS(N VALUE)U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION
SS
S-1
SS
S-2
SS
S-3
SS
S-4
SS
S-5
SS
S-6
SS
S-7
SS
S-8
6
12
18
12
18
18
18
18
6-2-2
(4)
1-0-0
(0)
5-5-8
(13)
5-3-3
(6)
7-8-10
(18)
2-3-7
(10)
1-0-1
(1)
1-1-1
(2)
SM
OH
SP-
SM
SP
SM
ML
SM
1.5
5.0
7.0
12.5
20.0
22.5
32.5
Recycled Concrete
(SM) Gray/brown fine silty sand (loose, moist) (Alluvium)
(OH) Gray/brown organic silt (very soft, wet) (Alluvium)
(SP-SM) Dark gray fine sand with silt and interbeds of silty sand (medium dense, wet) (Alluvium)
(SP) Dark gray fine to medium sand (medium dense, wet) (Alluvium)
(SM) Gray fine silty sand (medium dense, wet) (Alluvium)
(ML) Gray silt (very soft, wet) (Alluvium)
With shell debris
(SM) Gray fine silty sand with shell debris (medium dense, wet) (Alluvium)
NOTES
LOGGED BY ZLL
DRILLING METHOD Truck Mounted Drill Rig
DRILLING CONTRACTOR Holocene GROUND WATER LEVELS:
CHECKED BY JEB
DATE STARTED 3/16/18 COMPLETED 3/16/18
AT TIME OF DRILLING 17.50 ft
AT END OF DRILLING ---
AFTER DRILLING ---
HOLE SIZE 4.25" HSAGROUND ELEVATION
SAMPLE TYPENUMBERDEPTH(ft)0
5
10
15
20
25
30
35
(Continued Next Page)
PAGE 1 OF 2
Figure A-3
BORING NUMBER B-2
CLIENT HHJ Architects, PLLC
PROJECT NUMBER P1238-T18
PROJECT NAME Walker Renton Auto Dealership Geotech Report
PROJECT LOCATION 3400 East Valley Road, Renton, WA
COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 4/5/18 15:42 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1238-T18\P1238-T18 BORING LOGS.GPJMigizi Group, Inc.
PO Box 44840
Tacoma, WA 98448
Telephone: 253-537-9400
Fax: 253-537-9401
RECOVERY (in)(RQD)BLOWCOUNTS(N VALUE)U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION
SS
S-9
SS
S-10
SS
S-11
SS
S-12
18
18
18
18
3-4-6
(10)
3-5-3
(8)
4-5-5
(10)
7-9-9
(18)
SM
SM
40.0
51.5
(SM) Gray fine silty sand with shell debris (medium dense, wet) (Alluvium) (continued)
(SM) Gray fine silty sand (loose, wet) (Alluvium)
Grades to medium dense
Bottom of borehole at 51.5 feet.SAMPLE TYPENUMBERDEPTH(ft)35
40
45
50
PAGE 2 OF 2
Figure A-3
BORING NUMBER B-2
CLIENT HHJ Architects, PLLC
PROJECT NUMBER P1238-T18
PROJECT NAME Walker Renton Auto Dealership Geotech Report
PROJECT LOCATION 3400 East Valley Road, Renton, WA
COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 4/5/18 15:42 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1238-T18\P1238-T18 BORING LOGS.GPJMigizi Group, Inc.
PO Box 44840
Tacoma, WA 98448
Telephone: 253-537-9400
Fax: 253-537-9401
RECOVERY (in)(RQD)BLOWCOUNTS(N VALUE)U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION
ESC Plan for Construction Stormwater Pollution Prevention
Walker Auto Dealership
2180100.10
Appendix E
Sediment Pond Sizing
Project Wt4.11.C.O. P.VTo
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With/To
Project No r sl(60 \CO -
Phone
Fax #
1=I Page of
E Calculations
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O Memorandum
O Meeting Minutes
Telephone Memo
Address # Faxed Pages
Date ciiit./1 By NkTrt tkt,,DL Le'StAE ST-5P,
Civil Engineers
Structural Engineers
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Community Planners
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If this does not meet with your understanding, please contact us in writing within seven days. THANK YOU.
T
0+00 1+00 2+00 3+00 4+00 5+00 6+00 6+50
0+00 1+00 2+00 3+00 4+00 5+00 6+00 6+50
0+00 1+00 2+00 3+00 4+00 5+00 6+00 6+50
A
C2.2
B
C2.2
C
C2.2
0+001+002+003+004+005+005+250+001+002+003+004+005+005+250+001+002+003+004+005+005+25D
C2.3
E
C2.3
F
C2.3
FUTURE BUILDING
PAD SUBGRADE ELEV: 21.25 SR 167SW 34TH ST EAST VALLEY ROADFS: 18.07FS: 17.67FS: 13.71FS: 13.71FS: 18.03FS: 20.55FS: 20.48FS: 20.51FS: 20.55FS: 20.09FS: 19.34FS: 20.60FS: 20.56FS: 20.48FS: 20.39FS: 20.30FS: 20.17FS: 18.75FS: 18.66FS: 18.14FS: 17.52FS: 13.71FS: 13.71FS: 18.19FS: 20.57FS: 20.42FS: 20.08FS: 20.39FS: 20.21FS: 19.94FS: 20.51FS: 20.59FS: 20.54FS: 20.48FS: 20.43FS: 20.24FS: 19.67FS: 19.68FS: 18.69FS: 17.36FS: 13.71FS: 13.71FS: 18.34FS: 20.57FS: 20.55FS: 20.55FS: 20.55FS: 20.55FS: 20.64FS: 20.68FS: 20.69FS: 20.60FS: 20.56FS: 20.57FS: 20.54FS: 20.58FS: 20.57FS: 19.16FS: 17.21FS: 13.71FS: 13.71FS: 18.50FS: 20.47FS: 21.10FS: 20.94FS: 20.89FS: 20.88FS: 20.92FS: 20.57FS: 20.37FS: 20.22FS: 20.19FS: 20.14FS: 20.13FS: 19.57FS: 17.06FS: 13.71FS: 13.71FS: 18.65FS: 20.61FS: 21.17FS: 20.50FS: 20.32FS: 20.12FS: 19.90FS: 19.69FS: 19.82FS: 19.57FS: 16.91FS: 13.71FS: 13.71FS: 18.80FS: 20.74FS: 21.19FS: 20.28FS: 20.08FS: 19.87FS: 19.85FS: 19.91FS: 19.75FS: 16.75FS: 13.71FS: 13.71FS: 18.95FS: 20.99FS: 21.23FS: 20.26FS: 20.27FS: 20.29FS: 20.30FS: 20.31FS: 20.09FS: 16.60FS: 13.71FS: 13.71FS: 19.11FS: 21.25FS: 21.25FS: 20.48FS: 20.46FS: 20.45FS: 20.43FS: 20.42FS: 20.54FS: 16.45FS: 13.71FS: 13.71FS: 19.26FS: 21.25FS: 21.25FS: 20.29FS: 20.09FS: 19.96FS: 19.95FS: 19.95FS: 20.56FS: 20.06FS: 19.89FS: 19.78FS: 20.38FS: 21.25FS: 21.25FS: 20.33FS: 20.14FS: 19.93FS: 19.72FS: 19.83FS: 20.41FS: 19.99FS: 19.75FS: 19.65FS: 20.37FS: 20.39FS: 20.27FS: 20.22FS: 20.18FS: 20.14FS: 19.95FS: 20.16FS: 19.75FS: 19.44FS: 20.51FS: 20.45FS: 20.49FS: 20.52FS: 20.56FS: 20.58FS: 19.92FS: 20.42FS: 20.27FS: 20.31FS: 20.70FS: 20.59FS: 20.37FS: 20.17FS: 20.20FS: 20.22FS: 20.00FS: 21.05FS: 21.04FS: 21.06FS: 21.17FS: 21.19FS: 20.75FS: 20.55FS: 20.28FS: 20.01FS: 20.17FS: 19.91FS: 20.80FS: 20.80FS: 20.83FS: 20.95FS: 21.12FS: 21.12FS: 21.09FS: 21.10FS: 21.11FS: 21.11FS: 21.10FS: 21.08FS: 21.05FS: 20.96FS: 20.75FS: 20.58FS: 20.41FS: 20.29FS: 19.44FS: 20.53FS: 20.54FS: 20.58FS: 20.68FS: 20.78FS: 20.79FS: 20.80FS: 20.81FS: 20.83FS: 20.85FS: 20.87FS: 20.89FS: 20.90FS: 20.92FS: 20.94FS: 20.96FS: 20.92FS: 20.79FS: 20.44FS: 20.28FS: 20.31FS: 20.37FS: 20.42FS: 20.46FS: 20.48FS: 20.50FS: 20.53FS: 20.56FS: 20.58FS: 20.61FS: 20.63FS: 20.66FS: 20.68FS: 20.71FS: 20.73FS: 20.79FS: 19.25FS: 20.19FS: 20.27FS: 20.30FS: 20.33FS: 20.36FS: 20.39FS: 20.42FS: 20.45FS: 20.47FS: 20.62FS: 19.25FS: 19.67FS: 20.46FUTURE BUILDING OUTLINE
FUTURE EDGE OF PAVING (TYP.)FS: 18.96FS: 18.48FS: 21.06FS: 20.86FS: 20.74FS: 20.73FS: 20.82FS: 20.54FS: 19.58FS: 18.37FS: 20.65FS: 20.51FS: 20.39FS: 20.39FS: 20.58FS: 20.71FS: 20.54FS: 20.46FS: 20.54FS: 20.47FS: 20.38FS: 20.23FS: 20.15FS: 20.04FS: 20.10FS: 18.12FS: 18.94FS: 20.10FS: 19.80FS: 20.11FS: 20.22FS: 20.40FS: 20.33FS: 20.36FS: 20.03FS: 19.98FS: 19.95FS: 19.81FS: 19.61FS: 19.53FS: 19.37FS: 19.39FS: 19.37FS: 18.80FS: 19.43FS: 19.57FS: 19.16FS: 19.49FS: 19.20FS: 19.20FS: 18.95FS: 18.96FS: 19.01FS: 18.97FS: 18.40FS: 18.12FS: 17.62STRIPPED GRADE
CONTOUR
FINAL SUBGRADE
CONTOUR
TEMPORARY STORM PIPE
40 LF 12" CPEP @ 1.0%
SEDIMENT TRAP RISER
12" CPEP SW=14.0
TEMPORARY SEDIMENT TRAP
MIN. SURFACE AREA:1800 SF
BERM ELEV: 19.0
WS ELEV: 18.0
BOTTOM ELEV: 14.5
BERM ELEV: 19.0
BOTTOM ELEV: 14.5
RR
RR
SPILLWAY ELEV: 18.0
SF
MAINTAIN CONSTRUCTION
ENTERANCE
(TYP)
HIGH POINTFS: 21.03FS: 21.05FS: 21.09FS: 20.47FS: 21.10FS: 20.46FS: 21.11FS: 20.50FS: 21.11FS: 20.47FS: 21.11FS: 20.50FS: 21.16FS: 20.56FS: 21.12FS: 21.10FS: 21.18FS: 20.65FS: 21.02FS: 20.90TEMPORARY SEDIMENT TRAP
MIN. SURFACE AREA:1900 SF
BERM ELEV: 16.5
WS ELEV: 15.5
BOTTOM ELEV: 12.0
BERM ELEV: 16.5
BOTTOM ELEV: 12.0
REFER TO LANDSCAPE PLANS FOR
BUFFER RESTORATION2020202121
21
20
21212
1
20201920 2019CONTRACTOR TO PROTECT EXISTING BUILDING
AND STORM DRAIN SYSTEM. EXCAVATIONS SHALL
NOT ENTER ZONE OF INFLUENCE OF BUILDING
FOUNDATION.
OUTER SILT FENCE
CAN BE REMOVED
WHEN BUFFER IS
STABILIZED
N
GRAPHIC SCALE
0 30 60
1" = 30 FEET
15
EARTHWORK VOLUMES
ANTICIPATED CONTAMINATED SOIL REMOVAL
(ASSUMING 1' DEPTH OF REMOVAL): 9,100 CY
CUT:7,000 CY
FILL:19,800 CY
NET:12,800 (IMPORT)
NOTE:
VOLUMES ARE STRIPPED GRADE TO FINAL SUBGRADE.
THE ABOVE QUANTITIES ARE ESTIMATES ONLY
INTENDED FOR THE PERMITTING PROCESS. DO NOT
USE FOR BID PURPOSES. THE QUANTITIES DO NOT
HAVE STRIPPING, COMPACTION, OR CUT OR FILL
ADJUSTMENT FACTORS APPLIED TO THEM.
CITY OF
RENTON
IN COMPLIANCE WITH CITY OF RENTON STANDARDS
Civil Engineers
Structural Engineers
Landscape Architects
Community Planners
Natural Resource Ecologists
Land Surveyors
Neighbors
T A C O M A
2215 North 30th Street, Suite 300 Tacoma, WA 98403
253.383.2422TEL 253.383.2572FAX www.ahbl.comWEB
S E A T T L E
S P O K A N E T R I - C I T I E S
WALKER AUTO DEALERSHIP
EARLY CLEAR AND GRADE PLANS
AHBL JOB #2180100.10
9
Know what's below.
before you dig.Call
RTED-40-4018C:18004244LUA:18-000305PR:18000212R-40180
ROUGH GRADING AND TESC PLAN
C2.1
5
STABILIZE ALL DISTURBED AREAS
WITH ROCK SURFACING AND STRAW
Q:\2018\2180100\10_CIV\CAD\_Fill and Grade\2180100-SH-GRAD.dwgEATHWORK LEGEND
FS = FINAL SUBGRADE
FINAL SUBGRADE CONTOUR
STRIPPED SURFACE CONTOUR
NOTE: FINAL SUBGRADE SHALL BE UNDERLAIN BY 2.0'
OF STRUCTURAL FILL IN BUILDING AND PAVED AREAS
PER GEOTECHNICAL ENGINEER'S RECOMMENDATION.
ELEV
ELEV
75.00' WETLAND
BUFFER
TESC LEGEND
RIPRAP ROCKERY
6"-8" QUARRY SPALLS
GRAVEL CHECK DAM
INTERCEPTOR DITCH
@ 0.3% MINIMUM
INLET PROTECTION
SILT FENCE
CLEARING LIMITS
SEDIMENT TRAP RISER
CONSTRUCTION ENTRANCE
CL
SF
IP
ID
CD
RR
CE
CE
CE
SF
ID
ID
ID
SF
SF
SF
SF
5