HomeMy WebLinkAboutD_Admin_Report_And_Exhibits_3403_Burnett_Ave_S_Modification_191230DEPARTMENT OF COMMUNITY
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Project Location Map
D_Admin_Report_And_Exhibits_3403_Burnett_Ave_S_Modification_191230
A. ADMINISTRATIVE MODIFICATION REPORT & DECISION
Decision: APPROVED APPROVED SUBJECT TO CONDITIONS DENIED
Report Date: December 31, 2019
Project File Number: PR19-000389
Project Name: McCarthy Landscape Project
Land Use File Number: LUA19-000199, MOD, CAE
Project Manager: Brittany Gillia, Assistant Planner
Owner: Mary McCarthy, 3403 Burnett Ave N, Renton WA 98056
Applicant: Jason Laskelle, May Creek Landscaping, 1831 SE 32nd St, Bellevue WA 98005
Contact: Jason Laskelle, May Creek Landscaping, 1831 SE 32nd St, Bellevue WA 98005
Project Location: 3403 Burnett Ave N, Renton WA 98056
Project Summary: The applicant is requesting approval of a critical areas exemption and two (2)
modifications regarding the installation of an emergency retaining wall system for
the McCarthy Landscape Project located at 3403 Burnett Avenue North (Parcel
3342100020). These modifications will affect the installation of two (2) retaining
walls proposed on the western edge of this residential 0.125-acre parcel located in
the R-8 zone. The retaining wall system is being installed along the west edge of the
property as an emergency measure for erosion control on what is mapped as a
protected slope. Due to site constraints, two modifications are proposed to adjust
the shelf width and grade to maximize the structural integrity of the system within
the limited amount of space. The proposed retaining walls will impede current
erosion hazards along Lake Washington Blvd and result in permanently stabilizing
the slope. The applicant has proposed a landscaping plan with plants that will act as
a screen for the retaining walls while mitigating erosion and encouraging soil
stability. The applicant would also implement cover measures via an erosion control
blanket along the incline with a trench drain and catch basin filter at the bottom of
the slope. Geotechnical reports covering the modification request justification,
emergency exemption information, and impacts to neighboring properties as well
as a landscaping plan have been submitted with this request and are listed as
Exhibit 2, 3, 4 and Exhibit 6.
Site Area: 0.125 acres
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
City of Renton Department of Community & Economic Development Burnett Ave N Retaining Wall Modification Administrative Modification Report & Decision LUA19-000199, MOD
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B. EXHIBITS:
Exhibit 1: Administrative Modification Decision
Exhibit 2: Geotechnical Report- Modification Justification (dated August 26th, 2019)
Exhibit 3: Geotechnical Report- Emergency Exemption (dated September 6th, 2019)
Exhibit 4: Geotechnical Report- Impact Analysis (dated October 18th, 2019)
Exhibit 5: Site Plan and TESC Plan
Exhibit 6: Landscape Plan, prepared by Francine M Day Landscape Architecture, (dated August 21st,
2019).
Exhibit 7: Grading and Drainage Plan, prepared by Zipper Geo, (dated August 26th, 2019)
Exhibit 8: Construction and Erosion Control Details
C. FINDINGS OF FACT (FOF):
1. The Planning Division of the City of Renton accepted the above master application for review on August
29, 2019 and determined the application complete on August 29th, 2019.
2. The applicant’s submittal materials comply with the requirements necessary to process the modification
request (exhibits 2-8)
3. The project site is located at 3403 Burnett Ave N.
4. The project site is currently developed with a single-family residential dwelling. There is existing rockery
along the upper slope edge that would affect the proposed retaining walls.
5. Access to the site is provided via Burnett Ave N. No changes to site access is proposed.
6. Construction would be completed with hand-tools and would not require additional access.
7. The property is located within the Residential Medium Density (RMD) Comprehensive Plan land use
designation.
8. The site is located within the Residential-8 (R-8) zoning classification.
9. The site is mapped with Regulated Shorelines. Compliance with the Shoreline Management Act was
evaluated under LUA18-000653.
10. Critical Areas: Project sites which contain critical areas are required to comply with the Critical Areas
Regulations (RMC 4-3-050). Emergency Activities are listed in table 4-3-050-C.3 as exempt from the City’s
Critical Areas Regulations. Emergency activities are those which are undertaken to correct emergencies
that threaten the public health, safety and welfare. An emergency means that an action must be
undertaken immediately or within a time frame too short to allow full compliance with this Section, to
avoid an immediate threat to public health or safety, to prevent an imminent danger to public or private
property, or to prevent an imminent threat of serious environmental degradation. If activities exceed the
existing improved area or the public right-of-way, this exemption does not apply. In determining whether
to issue a letter of exemption for proposed activities, the Administrator shall find that:
Compliance Critical Areas Analysis
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
City of Renton Department of Community & Economic Development Burnett Ave N Retaining Wall Modification Administrative Modification Report & Decision LUA19-000199, MOD
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i. The activity is not prohibited by this or any other provision of the Renton Municipal
Code or State or Federal law or regulation;
Staff Comment: Based on staff’s review of the Geotechnical Reports (Exhibits 2-4), the
proposed project is not prohibited by the City’s Critical Areas Regulations listed in
RMC4-3-050-C.5 or other provisions of the Renton Municipal code or State or Federal
law or regulation.
ii. The activity will be conducted using best management practices as specified by
industry standards or applicable Federal agencies or scientific principles;
Staff Comment: Best management practices, as applicable for site constraints and
structural limitations of this proposal, have been detailed in a Geotechnical Report
(Exhibit 2).
iii. Impacts are minimized and, where applicable, disturbed areas are immediately
restored;
Staff Comment: Impacts to the site are minimized in this proposal. With the access
constraints of this property, contractors will use hand tools to work along the slope on
foot (Exhibit 2). Due to the permanent nature of stabilizing the over-steepened slope
and removing the invasive species present along the critical area, the proposed work
cannot be removed and the changes are noted to have positive long term impacts for
the site (Exhibits 3 and 4). Post-construction, the site will be planted with native
vegetation (Exhibit 6) that will add to the biodiversity of the site and improve the soil
stability along the slope.
iv. Where water body or buffer disturbance has occurred in accordance with an
exemption during construction or other activities, revegetation with native vegetation
shall be required;
Staff Comment: The proposed plantings (Exhibit 6) will provide soil stability and are all
attractive, low-maintenance foliage. Toward the top of the slope, Euonymus japonicus
‘Green Spire’ and Arbutus unedo ‘Compacta’ will act as screening for the galvanized
steel piles. These plants are ornamental evergreens that will provide year-round
coverage and seasonal flowers. Without this screening, bare galvanized steel retaining
walls would be visible and unattractive to traffic along Lake Washington Blvd. All other
plants chosen for the site specialize in erosion control and soil stability. These soil-
stabilizing plants will be planted along the hillside and include: Rosa rugosa ‘Hansa’,
Cornus sericea ‘Kelseyi’, Lonicera pileata, and Frangaria chiloensis. They are all
evergreen except for Cornus sericea ‘Kelseyi’, or Dwarf Red Oiser Dogwood, which will
shed its foliage and bring a bright red accent to the plantings during winter months.
Several of these plants have brightly colored flowers or berries. Overall, these plants
will increase visual interest and biodiversity along Lake Washington Boulevard while
increasing nearby public safety.
v. If a hazardous material, activity, and/or facility that is exempt pursuant to this
Section has a significant or substantial potential to degrade groundwater quality, then
the Administrator may require compliance with the Wellhead Protection Area
requirements of this Section otherwise relevant to that hazardous material, activity,
and/or facility. Such determinations will be based upon site and/or chemical-specific
data.
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
City of Renton Department of Community & Economic Development Burnett Ave N Retaining Wall Modification Administrative Modification Report & Decision LUA19-000199, MOD
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Staff Comment: Not applicable, the proposal does not include a hazardous material
activity or facility.
Geologically Hazardous Areas: Based upon the results of a geotechnical report and/or
independent review, conditions of approval for developments may include buffers
and/or setbacks from buffers. A standard 15-foot building setback is required for all
structures from Protected Slope areas.
A 50-foot buffer and 15-foot building setback are required from Very High Landslide
Hazard Areas.
Staff Comment: The project is located in an area of the property mapped with Moderate
Landslide Hazard, and Protected Slopes (40-90%). The emergency installation of the
retaining wall system on this protected slope is necessary to stop erosion from
happening along Lake Washington Boulevard and is an exempt activity as defined in
RMC 4-3-050.C.3 under footnote 24 for emergency activities. According to geotechnical
consultants Zipper Geo, public health, safety, and welfare would have been threatened
by erosion on this protected slope (Exhibit 3) if corrective actions were not taken. The
proposed construction will not result in a structure and will therefore be exempt from
the setback requirement. All developments will be kept out of public rights-of-way. A
preferred construction method has been explained in the geotechnical report prepared
by Zipper Geo (Exhibit 2) to minimize damage to the slope and reduce erosion hazards.
This method involves the use of hand tools and no large machinery. An additional report
(Exhibit 4) has been submitted by Zipper Geo to analyze the short and long term impacts
of this proposal that states these actions are necessary and beneficial for the slope and
its surroundings. Staff recommends as a condition of approval that the development
comply with the proposed construction methods of the report.
11. Shoreline Master Program Analysis: The site is within Shoreline Jurisdiction of Lake Washington, Reach D
(LW-D), designated Shoreline Residential. The work has been evaluated under Shoreline Exemption
LUA18-000653 and no significant impacts to the Lake Washington Shoreline have been found.
12. Modification Analysis: The applicant is requesting a modification from RMC 4-4-040C.2.f to allow the
grading at the bottom of the retaining walls to be at a 1.8% slope for a 3 ft. distance in place of the 4 ft.
distance and 0% slope required. The proposed slope will include erosion-mitigating plantings to reinforce
the stability of the system. The applicant is also requesting a modification from RMC 4-4-040C.2.e.i to
reduce the required terrace width for the top retaining wall from 4 ft. to 3 ft. to facilitate both retaining
walls in the system and keep all walls outside the required setback from public rights-of-way as noted in
RMC 4-4-040C.2.d. The proposal is compliant with the following modification criteria, pursuant to RMC 4-
9-250, if all conditions of approval are met. Therefore, staff is recommending approval of the requested
modification, subject to conditions as noted below:
Compliance Modification Criteria and Analysis
a. Substantially implements the policy direction of the policies and objectives of the
Comprehensive Plan Land Use Element and the Community Design Element and
the proposed modification is the minimum adjustment necessary to implement
these policies and objectives.
Staff Comment: This proposal aligns with the City’s Comprehensive Plan by mitigating
erosion along the hillside of the parcel using a detailed TESC plan and an erosion
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
City of Renton Department of Community & Economic Development Burnett Ave N Retaining Wall Modification Administrative Modification Report & Decision LUA19-000199, MOD
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reducing landscaping plan (Policy L-29). The project will be functional and attractive
(Policy L-57, Goal L-BB) while preventing possible damage to Lake Washington Blvd
(Policy L-37). The low-impact method of construction (Policy L-29) will ultimately
stabilize the slope and create a safer, more biodiverse environment around Lake
Washington. The current proposal is at its structural limit and if not implemented may
result in a high risk of erosion and future property damage for the property owners as
well as the City of Renton.
b. Will meet the objectives and safety, function, appearance, environmental
protection and maintainability intended by the Code requirements, based upon
sound engineering judgment.
Staff Comment: The applicant contends that installing the proposed retaining walls will
improve safety and appearance of the site and adjoining slope along Lake Washington
Blvd.
Staff concurs the proposed modification would meet the objectives of function and
maintainability intended by the code requirements by implementing this structurally
maximized TESC system. Implementing the proposed retaining walls will increase the
long-term stability of the parcel and allow the landscape to screen and stabilize the
slope along Lake Washington Blvd. Staff recommends as a condition of approval that
the applicant shall schedule an inspection with the City of Renton to ensure the
landscaping has been properly planted and that construction of the retaining walls have
been implemented properly.
c. Will not be injurious to other property(ies) in the vicinity.
Staff Comment: The applicant contends the modification would have no negative
impact to neighboring properties. A geotechnical report (Exhibit 4) was sent to staff on
October 28th 2019 that states foreseen short and long-term impacts of the project. The
report states that the project will benefit the safety of adjacent public access along Lake
Washington Boulevard as well as provide stabilization benefits to neighboring
properties.
Staff concurs the requested modification would have no impact to other properties in
the vicinity. The modified hillside would be accessed solely by foot through the
homeowner’s property and the construction will be implemented within property lines.
d. Conforms to the intent and purpose of the Code.
Staff Comment: See comments under criterion ‘b’.
e. Can be shown to be justified and required for the use and situation intended; and
Staff Comment: See comments under criterion ‘b’.
f. Will not create adverse impacts to other property(ies) in the vicinity.
Staff Comment: See comments under criterion ‘c’.
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
City of Renton Department of Community & Economic Development Burnett Ave N Retaining Wall Modification Administrative Modification Report & Decision LUA19-000199, MOD
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E. DECISION:
The proposal satisfies 6 of the 6 criteria listed in RMC 4-9-250 for approval of modifications and 5 of the 5 criteria
listed in RMC 4-3-050 for exemptions of critical area regulations. Therefore, the McCarthy Landscape Project
Modification, File No. LUA19-000199, MOD, CAE is approved and is subject to the following conditions:
1. Applicant shall follow construction methods through the entire construction process for any development
of retaining walls located on the west end of 3403 Burnett Ave S per the recommendation of the
Geotechnical Report and Modification Justification included as Exhibit 2.
2. Applicant shall schedule an inspection with the City of Renton Current Planning department and any
related parties prior to project completion to ensure compliance with construction and engineering
specifications as well as to confirm the proposed planting plan has been implemented to meet City of
Renton standards.
DATE OF DECISION ON LAND USE ACTION:
SIGNATURE:
Jennifer Henning, Planning Director Date
TRANSMITTED on December 31, 2019 to the Owner/Applicant/Contact:
Owner: Applicant/Contact:
Mary McCarthy
3404 Burnett Ave N
Renton, WA 98056
Jason Laskelle
May Creek Landscaping
1831 SE 32nd St.
Bellevue, WA 98005
TRANSMITTED on December 31, 2019 to the Parties of Record:
None
TRANSMITTED on December 31, 2019 to the following:
Chip Vincent, CED Administrator
Brianne Bannwarth, Development Engineering Manager
Amanda Askren, Property Services
Vanessa Dolbee, Current Planning Manager
Rick Marshall, Fire Marshal
K. LAND USE ACTION APPEALS, REQUEST FOR RECONSIDERATION, & EXPIRATION:
The administrative land use decision will become final if the decision is not appealed within 14 days of the decision
date.
APPEAL: This administrative land use decision will become final if not appealed in writing to the Hearing
Examiner on or before 5:00 PM on January 14, 2019. An appeal of the decision must be filed within the 14-day
appeal period (RCW 43.21.C.075(3); WAC 197-11-680), together with the required fee to the Hearing Examiner,
City of Renton, 1055 South Grady Way, Renton, WA 98057. RMC 4-8-110.B governs appeals to the Hearing
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
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City of Renton Department of Community & Economic Development Burnett Ave N Retaining Wall Modification Administrative Modification Report & Decision LUA19-000199, MOD
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Examiner and additional information regarding the appeal process may be obtained from the City Clerk’s Office,
(425) 430-6510.
EXPIRATION: The Modification decision will expire two (2) years from the date of decision. A single one (1) year
extension may be requested pursuant to RMC 4-9-250.
RECONSIDERATION: Within 14 days of the decision date, any party may request that the decision be reopened by
the approval body. The approval body may modify his decision if material evidence not readily discoverable prior
to the original decision is found or if he finds there was misrepresentation of fact. After review of the
reconsideration request, if the approval body finds sufficient evidence to amend the original decision, there will
be no further extension of the appeal period. Any person wishing to take further action must file a formal appeal
within the 14-day appeal time frame.
THE APPEARANCE OF FAIRNESS DOCTRINE: provides that no ex parte (private one-on-one) communications may
occur concerning the land use decision. The Doctrine applies not only to the initial decision, but to Appeals to the
Hearing Examiner as well. All communications after the decision/approval date must be made in writing through
the Hearing Examiner. All communications are public record and this permits all interested parties to know the
contents of the communication and would allow them to openly rebut the evidence in writing. Any violation of
this doctrine could result in the invalidation of the appeal by the Court.
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
CITY OF RENTON
DEPARTMENT OF COMMUNITY AND ECONOMIC DEVELOPMENT
ADMINISTRATIVE MODIFICATION REPORT & DECISION
EXHIBITS
Project Name:
McCarthy Landscape Project
Land Use File Number:
LUA19-000199, MOD
Date of Report
December 24, 2019
Staff Contact
Brittany Gillia
Assistant Planner
Project Contact/Applicant
Jason Laskelle
May Creek Landscaping
1831 SE 32nd St, Bellevue
WA 98005
Project Location
3403 Burnett Ave N,
Renton WA 98056
The following exhibits are included with the Administrative Modification Report:
Exhibit 1: Administrative Modification Decision
Exhibit 2: Geotechnical Report- Modification Justification (dated August 26th, 2019)
Exhibit 3: Geotechnical Report- Emergency Exemption (dated September 6th, 2019)
Exhibit 4: Geotechnical Report- Impact Analysis (dated October 18th, 2019)
Exhibit 5: Site Plan and TESC Plan
Exhibit 6: Landscape Plan, prepared by Francine M Day Landscape Architecture, (dated
August 21st, 2019).
Exhibit 7: Grading and Drainage Plan, prepared by Zipper Geo, (dated August 26th, 2019)
Exhibit 8: Construction and Erosion Control Details
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
19019 36th Avenue West, Suite E Lynnwood, Washington 98036 (425) 582-9928
Zipper Geo Associates, LLC
Geotechnical and Environmental Consulting
Project No. 2041.01
August 26, 2019
Mary McCarthy
3403 Burnett Avenue North
Renton, WA 98105
Subject: Land Use Code Modification Request
McCarthy Slope Stabilization
3403 Burnett Avenue North
Renton, WA
Dear Ms. McCarthy:
Zipper Geo Associates, LLC prepared retaining wall construction plans and stability calculations for the
proposed slope stabilization project located on your property dated August 8th , 2019. The City of
Renton Land Use department reviewed those plans and indicated that modifications to the plans are
required in order to meet Section 4-4-040.2.e.i and 4-4-040.2.f of the Renton Municipal Code (the
Code). It is not feasible to meet those requirements and the purpose of this letter is to provide required
information in support of a Land Use Code Modification Request as required and described in the
Renton Planning Division’s Submittal Requirements, Modification document. The requested
information or reference to it is provided below.
1. Pre-Application Meeting Summary: A formal pre-application meeting was not held. However,
email correspondence with Ms. Vanessa Dolbee was completed and through that
correspondence, Ms. Dolbee has indicated that it appears the modification can be approved.
2. Wavier Form: No waiver form was provided.
3. Land Use Permit Master Application Form: A land use permit master application form was
previously submitted and is also attached to this letter.
4. Fees: Fees have not been submitted, however Ms. Dolbee has indicated the fee will be
determined after the Modification submittal information has been received.
5. Project Narrative: The project will consist of constructing a two-tiered retaining wall and
associated landscaping on a slope located along the west side of the subject property. The
slope is currently experiencing erosion and shallow landslide instability. The purpose of the
retaining walls and landscaping is to permanently stabilize the slope. Detailed information
regarding the geometry of the proposed retaining walls and landscaping can be found on the
attached plans.
6. Justification for the Modification Request to Section 4-4-040.2.e.i: Section 4-4-040.2.e.i of
the Code requires that “The width of a terrace shall be equal to the height of the tallest abutting
retaining wall; however, the minimum terrace width shall be two feet (2').” The tallest abutting
retaining wall under the current proposal is 4 feet. As such, this section of the Code would
require a minimum terrace width of 4 feet. Under the current proposal, a terrace width of only
EXHIBIT 2
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
Zipper Geo Associates, LLC
McCarthy Slope Stabilization
Project No. 2041.01
August 26, 2019
19023 36th Avenue West, Suite D Lynnwood, Washington 98036 (425) 582-9928
Page 2
3 diverging to 4 feet can be provided for approximately the south half of the upper proposed
retaining wall (Wall 2). The only feasible retaining wall system that can work at this site due to
access constraints is one installed with hand-carried equipment as currently proposed. The
proposed wall system is at it’s structural limit. Moving Wall 2 down-slope to provide the 4 foot
terrace width for the entire wall length would result in inadequate structural capacity for the
lower wall (Wall 1) as the upper wall would begin to impose passive lateral earth pressures on
the lower wall therefor requiring a wall with larger structural elements that cannot be installed
with hand-carried equipment. Adding capacity to the lower wall through installation of
additional piles is not feasible as the piles are spaced as close as reasonably feasible such that
they do not interact therefore reducing capacity. Using machined equipment to install larger
structural elements is not feasible as the existing home blocks access to the area from the top
and such equipment would have inadequate reach from the bottom.
Justification for the Modification Request to Section 4-4-040.2.f: Section 4-4-040.2.f of the
Code requires that “For land area that is not between two (2) retaining walls (i.e., not a terrace),
the lower soil grade (i.e., ground at the bottom of a retaining wall’s exposed surface) and the
upper soil grade (i.e., ground at the top a retaining wall) abutting a retaining wall shall be level
for a horizontal distance (measured perpendicularly to the wall) equaling one foot (1') for every
one foot (1') in height of the retaining wall.” This section would require a level grade at the
bottom of the lower wall (Wall 1) extending 4 feet from the wall face. A gently sloping grade
extending only 3 feet from the wall face can be provided under the current proposal. Providing
a level grade distance of 4 feet would require the height of Wall 1 to be increased or the tier
width between Walls 1 and 2 to be decreased. For similar reasons under the justification for
Section 4-4-040.2.e.i, a 4 feet level grade distance cannot be provided. The current proposal is
at it’s structural limit.
Modification Compliance: We interpret that the primary intent of the land use requirements
under the sections in which modifications are requested is one of aesthetics. It is our opinion
the proposed modification substantially meets the land use element by providing 3 of the 4
feet required and is the minimum adjustment needed to allow for the proposed retaining wall
system. Providing 3 of the 4 feet will still allow for landscaping and an aesthetically pleasing
finished product. The proposed modification allows for safety and environmental protection
by stabilizing an otherwise relatively unstable slope. The proposed modification will not be
injurious to other properties in the vicinity as it still provides a majority of the requirements.
The modification is justified and required based on reasons cited above. The modification will
not create adverse impacts to other properties as it provides a majority of the requirements.
7. Neighborhood Detail Map: See attached.
8. Site Plan: See attached plans.
9. Architectural Elevations: See attached plans.
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
Zipper Geo Associates, LLC
McCarthy Slope Stabilization
Project No. 2041.01
August 26, 2019
19023 36th Avenue West, Suite D Lynnwood, Washington 98036 (425) 582-9928
Page 3
Respectfully submitted,
Zipper Geo Associates, LLC
Robert A. Ross, P.E.
Principal
8/26/19
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
19019 36th Avenue West, Suite E Lynnwood, Washington 98036 (425) 582-9928
Zipper Geo Associates, LLC
Geotechnical and Environmental Consulting
Project No. 2041.01
September 6, 2019
Mary McCarthy
3403 Burnett Avenue North
Renton, WA 98105
Subject: Land Use Emergency Exemption
McCarthy Slope Stabilization
3403 Burnett Avenue North
Renton, WA
Dear Ms. McCarthy:
Zipper Geo Associates, LLC prepared retaining wall construction plans and stability calculations for the
proposed slope stabilization project located on your property dated August 8th , 2019. The City of
Renton Land Use department was apparently unaware of the emergency nature of this project. After
correspondence with Ms. Vanessa Dolbee, City of Renton Planning Manager regarding the emergency
nature of this project, Ms. Dolbee has requested additional information in order to grant the project a
temporary emergency exemption from certain land use code requirements. The purpose of this letter
is to provide the requested information such that the city will grant an exemption and the work can be
completed prior to the beginning of the upcoming rainy season.
In our opinion, the area in which the work is proposed is currently unstable and presents an
unacceptable level of risk to the safety of the public who use the street below the slope and an
unacceptable risk of damage to the McCarthy property. Evidence of this risk is clearly observable on
the slope, primarily characterized by cracks on the surface of the slope indicating failure. We highly
recommend the work outlined in our August 8th, 2019 plans be implemented as soon as possible and
absolutely prior to the onset of the coming rainy season.
In accordance with Section 4-3-050, C of the Renton Municipal Code (the Code), work of an emergency
nature is permitted within critical areas and their associated buffers provided that the criteria outline
in Section 4-3-050, C, footnote 27 is met. Our comments regarding the footnote 27 criteria are
provided below.
• 27 A: As discussed above, It is our opinion an unacceptable threat to life or sever loss of
property will occur if an emergency permit is not granted. The slope is unstable as discussed
above.
• 27 B: It is our opinion the anticipate threat may occur before permit can be issued or modified
under the procedures otherwise required by this Section and other applicable laws. If the slope
is left in its current condition and exposed to rainfall or rising groundwater levels as a result of
rainfall, further failure may occur depositing landslide debris in the roadway below and further
EXHIBIT 3
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
Zipper Geo Associates, LLC
McCarthy Slope Stabilization
Project No. 2041.01
September 6, 2019
19023 36th Avenue West, Suite D Lynnwood, Washington 98036 (425) 582-9928
Page 2
destabilization of the land beyond the top of the slope. It is our understanding that under the
procedures otherwise required by this section of the Code and other sections, a permit would
not likely be granted until after the upcoming rainy season begins.
• 27 C: The standards and criteria for nonemergency activities have been incorporated into the
proposed measures. Specifically, the proposed structural solution meets typical safety factor
requirements and the area will be replanted.
With regard to time requirements, the work can be completed within 90 days. However, footnote 27
requires the area be restored to original condition. This is not feasible. The proposed work cannot be
removed as the area would then become unstable. This work is required to permanently stabilize the
slope and is the only feasible alternative we have been able to develop considering other code
requirements and site access constraints as previously discussed.
With regards to Shoreline Regulations, emergency construction is allowed under similar circumstances
as critical areas. The above information provides a basis for emergency construction as related to
Shoreline Regulations. As required by Shoreline, Critical Areas, and other code regulations, we will
continue to pursue any permits which would have been required for the work absent the above-
described emergency situation.
Respectfully submitted,
Zipper Geo Associates, LLC
Robert A. Ross, P.E.
Principal
Copies:
Vanessa Dolbee (City of Renton) – 1 electronic copy, Scott Warlick (City of Renton) – 1 electronic copy,
Jennifer Henning (City of Renton) – 1 electronic copy, Brianne Bannwarth (City of Renton) – 1 electronic
copy, Brittany Gillia (City of Renton) – 1 electronic copy, Jason Laskelle (May Creek Landscaping) – 1
electronic copy
9/6/19
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
19019 36th Avenue West, Suite E Lynnwood, Washington 98036 (425) 582-9928
Zipper Geo Associates, LLC
Geotechnical and Environmental Consulting
Project No. 2041.01
October 18, 2019
Mary McCarthy
3403 Burnett Avenue North
Renton, WA 98105
Subject: Short and Long Term Impacts
McCarthy Slope Stabilization
3403 Burnett Avenue North
Renton, WA
Dear Ms. McCarthy:
Zipper Geo Associates, LLC prepared retaining wall construction plans and stability calculations for the
proposed slope stabilization project located on your property dated August 8th , 2019. The City of
Renton granted an emergency exemption to begin the work prior to obtaining all of the necessary
permits due to the emergency nature of the project. As a condition to granting the exemption, the
City will not finalize the permit until a Shoreline Permit, Critical Areas Permit, and a Wall Modification
have been approved. In order to further process the required additional permits/approvals, the City
has requested a narrative describing the short and long term impacts the project may have on adjacent
properties. The purpose of this letter is to provide that narrative.
Short Term Impacts
The project involves earth work on a steep slope with areas of relatively unstable soils. The work will
expose soils highly susceptible to erosion. Additionally, the work could result in shallow landslides in
the unstable soils. The potential impacts of erosion are deposition and transport of sediment off-site.
The potential impacts of landslides include safety concerns for the traveling public along Lake
Washington Boulevard below and potentially destabilizing areas along the sides and tops of the slope.
The project plans were developed to mitigate the potential short term impacts through the use of
temporary erosion and sediment control measures and observation of construction by a geotechnical
engineer from Zipper Geo Associates. The work is currently proceeding and the mitigation measures
outlined in the plans are proving successful at mitigating the potential short term impacts.
Long Term Impacts
The long term impacts of the project are, in our opinion, beneficial to neighboring properties.
Specifically, prior to construction, the slope was over-steepened, covered with invasive plant species,
and contained areas of unstable soils. The project will stabilize an otherwise unstable slope, which if
failed, would have negative impacts on adjacent properties. The project will remove invasive species
and replace them with non-invasive species therefore increasing the potential for biodiversity in the
area. As such, we do not foresee negative long term impacts associated with the work.
EXHIBIT 4
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
Zipper Geo Associates, LLC
McCarthy Slope Stabilization
Project No. 2041.01
October 18, 2019
19023 36th Avenue West, Suite D Lynnwood, Washington 98036 (425) 582-9928
Page 2
We trust this information meets the City’s current request. If we can be of further assistance, please
contact us.
Respectfully submitted,
Zipper Geo Associates, LLC
Robert A. Ross, P.E.
Principal
Copies:
Vanessa Dolbee (City of Renton) – 1 electronic copy, Jason Laskelle (May Creek Landscaping) – 1
electronic copy
10/18/19
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
EXHIBIT 5
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
FIGUREJob No.Zipper Geo Associates, LLC19019 36th Ave. W.,Suite ELynnwood, WASHT. of11NEIGHBORHOOD DETAIL MAP2041.01DATE: AUGUST 20191MCCARTHY RESIDENCE SLOPE STABILIZATION3403 BURNETT AVENUE NORTHRENTON, WASCALE IN FEET010010050PROJECT SITEN 34TH ST.N 35TH ST.BURNETT AVE. N
LAKE WA BLVD. N DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
DESIGNED:SCALE:CHECKED:DRAWN:DATE:SHEETJOB NO.OFBYDESCRIPTIONDATENO.PLOT DATE:DRAWING19019 36th Avenue West, Suite E |Lynnwood, WA 98036PH: (425) 582-9928 | Fax: (425) 582-9930 | www.zippergeo.comSUBMITTAL RECORD8/26/19LAST EDIT:RobZ:\Projects\2001 - 2050\2041 McCarthy Residence\2041.01 McCarthy Residence\Working File\Drafting\2041.01 Plans REV 3.dwgRAR4/25/19-INITIAL RELEASE6MCCARTHY RESIDENCE SLOPE STABILIZATION3403 BURNETT AVENUE NORTHRENTON, WASHINGTON8/8/192041.01TAJRARRARRAR7/25/19-REDESIGN W/PIN PILE WALLS - INITIAL RELEASE8/26/19RAR8/8/191REVISED PER CITY REVIEW COMMENTSRAR8/26/192REVISION TO ADDRESS PLANNING COMMENTSAS SHOWNCONTACT INFORMATION:CLIENT:MARY MCCARTHY3403 BURNETT AVENUE NORTHRENTON, WA 98327(253) 720-0126LANDSCAPE ARCHITECT:FRANCINE M DAY LANDSCAPE ARCHITECTURE700 NW 42ND STREET, #409SEATTLE, WA 98107(206) 930-7493GEOTECHNICAL ENGINEER:ZIPPER GEO ASSOCIATES, LLC19019 36TH AVE. WEST, SUITE ELYNNWOOD, WA 98036(425) 582-9928CONTACT: Robert Ross, P.E.rross@zippergeo.comSHEET INDEXC1.0 - SITE AND TESC PLANC2.0 - TESC NOTES AND DETAILSC3.0 - GRADING AND DRAINAGE PLANC3.1 - DETAILSC3.2 - DETAILSC3.3 - DETAILSAPPROXIAMTE SCALE IN FEET051010BASEMAP FROM TOPOGRAPHIC SURVEY BY TYEE SURVEYORS DATED 6/14/18 AND MODIFIED BY ZGAINSTALL CATCHBASIN FILTERHATCHED AREA INDICATESAPPROXIMATE LIMITS OF SLOPESTABILIZATION WORK3403 BURNETT AVENUENORTHPROPOSED RETAINING WALLSEXISTING ROCKERYDocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
TEMPORARY EROSION AND SEDIMENT CONTROL GENERAL NOTESPART 1 - GENERAL1.THE SUCCESS OF THIS PROJECT IS HIGHLY DEPENDANT ONCONTROL OF SURFACE WATER RUNOFF INTO THE WORKAREA TO PREVENT EROSION AND FURTHER DESTABILIZATIONOF THE SLOPE.2.COMPLETION OF THIS PROJECT WILL REQUIRE TEMPORARILYREMOVING VEGETATION FROM A STEEP SLOPE. THEEXPOSED SURFACE MUST BE PROTECTED FROM EXPOSURETO DIRECT RAINFALL AND SURFACE WATER RUNOFF TO THEEXTENT POSSIBLE DURING CONSTRUCTION. IF WETWEATHER IS EXPECTED (DEFINED AS FORECAST RAINFALLGREATER THAN 0.25 INCHES IN A 12 HOUR PERIOD), AT THEEND OF EACH WORK DAY, THE SLOPE SHALL BE COVEREDWITH ANCHORED PLASTIC SHEETING. AREAS OF THE SITETHAT WILL BE UN-WORKED FOR MORE THAN TWO DAYSSHOULD BE COVERED WITH ANCHORED PLASTIC SHEETING.DEPENDING ON THE CONSTRUCTION PROGRESS, THERE MAYBE A NEED TO TEMPORARILY DELAY WORK AT THE SITE IFHEAVY RAINFALL IS FORECAST. TEMPORARY WORK DELAYSDURING CONSTRUCTION WILL BE EVALUATED ON ACASE-BY-CASE BASIS THROUGH OBSERVATION OF SITECONDITIONS BY ZIPPER GEO ASSOCIATES IN COORDINATIONWITH THE CONTRACTOR.3.CONSTRUCTION EROSION CONTROL MEASURES MUST BE INPLACE AND APPROVED BY THE ENGINEER AND CITY PRIOR TOANY EARTH DISTURBANCE.4.THE IMPLEMENTATION OF THE TEMPORARY EROSION ANDSEDIMENT CONTROL (TESC) PLANS AND THE CONSTRUCTION,MAINTENANCE, REPLACEMENT AND UPGRADING OF THE TESCFACILITIES IS THE RESPONSIBILITY OF THE CONTRACTORUNTIL ALL CONSTRUCTION IS APPROVED AND SITE ISPERMANENTLY STABILIZED.5.THE CONTRACTOR SHALL PROVIDE AND MAINTAINTEMPORARY SEDIMENTATION COLLECTION FACILITIES TOENSURE THAT SEDIMENT-LADEN WATER DOES NOT ENTERTHE PUBLIC DRAINAGE SYSTEM. AS CONSTRUCTIONPROGRESSES AND UNEXPECTED (SEASONAL) CONDITIONSDICTATE, MORE TEMPORARY SEDIMENTATION COLLECTIONFACILITIES MAY BE REQUIRED TO PREVENT VIOLATINGAPPLICABLE WATER STANDARDS. THEREFORE, DURING THECOURSE OF CONSTRUCTION IT SHALL BE THE OBLIGATIONAND RESPONSIBILITY OF THE CONTRACTOR TO ADDRESS ANYNEW CONDITIONS THAT MAY BE CREATED BY THEIRACTIVITIES AND TO PROVIDE ADDITIONAL FACILITIES THATMAY BE NEEDED TO PROTECT ADJACENT PROPERTIES.6.THE TESC FACILITIES SHOWN ON THESE PLANS MUST BECONSTRUCTED IN CONJUNCTION WITH ALL CLEARING ANDGRADING ACTIVITIES, AND IN SUCH A MANNER AS TO ENSURETHAT SEDIMENT-LADEN WATER DOES NOT LEAVE THE SITE,ENTER THE DRAINAGE SYSTEM, OR VIOLATE APPLICABLEWATER STANDARDS.7.NO SEDIMENT SHALL BE TRACKED INTO THE STREET ORPAVED SURFACES. SEDIMENT SHALL BE REMOVED FROMTRUCKS AND EQUIPMENT PRIOR TO LEAVING THE SITE. IN THEEVENT OF FAILURE OF THE EROSION CONTROL SYSTEMRESULTING IN SEDIMENT BEING TRACKED ONTO PAVEDSURFACES, THE CONTRACTOR SHALL IMMEDIATELYIMPLEMENT MEASURES TO CORRECT THE SITUATION, ANDVACUUM STREET SWEEPING SHALL BE EMPLOYED ON ANEMERGENCY BASIS. IF VACUUM STREET SWEEPING VEHICLESARE UTILIZED, THEY SHALL BE OF THE TYPE THAT REMOVESTHE SEDIMENT FROM THE PAVEMENT. WASHING OF THESTREETS WILL NOT BE ALLOWED WITHOUT PRIOR CITY OFRENTON APPROVAL.8. AREAS NOT WORKED FOR MORE THAN 2 DAYS SHALL BECOVERED WITH ANCHORED PLASTIC SHEETING.PART 1 - GENERAL CONT.9.NO SEDIMENT SHALL BE ALLOWED TO ENTER ANY CATCHBASIN WITHIN THE SITE, OR ADJACENT PROPERTIES. IN THEEVENT OF A FAILURE OF THE TESC PLAN THAT RESULTS INSEDIMENT ENTERING A CATCH BASIN, THE CONTRACTORSHALL REMOVE ALL SUCH SEDIMENT IMMEDIATELY.10.DISTURBED SOILS THAT ARE EXPOSED TO SURFACE RUNOFFSHALL BE IMMEDIATELY STABILIZED WITH TESC MEASURESAND APPROVED BY THE ENGINEER AND CITY.11.THE TESC FACILITIES SHALL BE INSPECTED DAILY BY THECONTRACTOR AND MAINTAINED AS NECESSARY TO ENSURETHEIR CONTINUED FUNCTIONING.12.CATCH BASINS IN THE STREET SHALL BE INSPECTED BY THECONTRACTOR DAILY. WATER LEAVING THE SITE DURINGCONSTRUCTION, INCLUDING WATER CARRIED BY TRUCKS,SHALL BE CLEAN. THE CONTRACTOR SHALL CLEAN CITYCATCH BASINS AND IMPLEMENT EXTRA SEDIMENTATIONCONTROL MEASURES IF NECESSARY AND AS DIRECTED BYTHE CITY OF RENTON INSPECTOR/DOE INSPECTOR AT NOADDITIONAL EXPENSE TO OWNER.13.THE TESC FACILITIES SHALL BE MAINTAINED UNTILPERMANENT EROSION CONTROL (REVEGETATION WITHTREES, SHRUBS, GROUND COVER, ETC.) PER THEAPPOROVED PLANS IS IN PLACE.14.WHERE SEEDING FOR TEMPORARY EROSION CONTROL ISUSED, FAST GERMINATING GRASSES SHALL BE APPLIED ATAN APPROPRIATE RATE.15.WHERE STRAW MULCH FOR TEMPORARY EROSION CONTROLIS USED, IT SHALL BE APPLIED AT A MINIMUM THICKNESS OFTWO INCHES.16.THE CONTRACTOR IS SOLELY RESPONSIBLE FOR ALL MEANSAND METHODS AND SEQUENCING OF TESC MEASURES ANDENSURING WATER QUALITY REQUIREMENTS ARE MET.PART 2 - TEMPORARY EXCAVATION STABILITY1.A TEMPORARY EXCAVATION WILL BE REQUIRED TO REMOVELOOSE SOIL FROM AN AREA IN THE SOUTHERN PORTION OFTHE SLOPE. TEMPORARY EXCAVATION SLOPE STABILITY IS AFUNCTION OF MANY FACTORS, INCLUDING: GROUNDWATERSEEPAGE, THE TYPE AND DENSITY OF THE VARIOUS SOILSTRATA, THE DEPTH OF CUT; SURCHARGE LOADINGSADJACENT TO THE EXCAVATION, AND THE LENGTH OF TIMETHE EXCAVATION REMAINS OPEN.2.AS THE CONTRACTOR IS CONTINUOUSLY PRESENT AT THESITE AND ABLE TO CONTINUOUSLY OBSERVE SITECONDITIONS, THE CONTRACTOR SHOULD BE RESPONSIBLEFOR MAINTENANCE OF SAFE SLOPES AND WORKER SAFETY.WE RECOMMEND THE CONTRACTOR CONTINUOUSLYOBSERVE TEMPORARY EXCAVATIONS FOR INDICATIONS OFINSTABILITY SUCH AS SOIL SLUMPS, GROUNDWATERSEEPAGE AT THE SURFACE OF THE SLOPE, AND CRACKS ORDOWN SETTING OF THE GROUND SURFACE AT THE TOP OFTHE SLOPE OR ALONG ANY PORTION OF THE SLOPE. IF SIGNSOF INSTABILITY ARE OBSERVED, THE CONTRACTOR SHALLSTOP WORK AND CONTACT ZIPPER GEO ASSOCIATESIMMEDIATELY FOR FURTHER OBSERVATION ANDRECOMMENDATIONS.3.ZIPPER GEO ASSOCIATES (ZGA) SHALL PROVIDE PERIODICOBSERVATION OF GRADING AND RESTORATION AS ITPROCEEDS. ZGA SHALL OBSERVE THE SITE AND TEMPORARYEXCAVATIONS IMMEDIATELY AFTER A RAINFALL EVENTTOTALING 0.5 INCHES OR MORE IN A 24 HOUR PERIOD.TEMPORARY PLASTIC COVERINGCATCH BASIN INSERTDESIGNED:SCALE:CHECKED:DRAWN:DATE:SHEETJOB NO.OFBYDESCRIPTIONDATENO.PLOT DATE:DRAWING19019 36th Avenue West, Suite E |Lynnwood, WA 98036PH: (425) 582-9928 | Fax: (425) 582-9930 | www.zippergeo.comSUBMITTAL RECORD8/26/19LAST EDIT:RobZ:\Projects\2001 - 2050\2041 McCarthy Residence\2041.01 McCarthy Residence\Working File\Drafting\2041.01 Plans REV 3.dwgRAR4/25/19-INITIAL RELEASE6MCCARTHY RESIDENCE SLOPE STABILIZATION3403 BURNETT AVENUE NORTHRENTON, WASHINGTON8/8/192041.01TAJRARRARRAR7/25/19-REDESIGN W/PIN PILE WALLS - INITIAL RELEASE8/26/19RAR8/8/191REVISED PER CITY REVIEW COMMENTSRAR8/26/192REVISION TO ADDRESS PLANNING COMMENTSNOT TO SCALEDocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
EXHIBIT 6DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
SDSDSDSDSDCB 132700 RIM = 44.13'IE 12" RCP NE, SE = 42.21'SD
SDSDSDINSTALL 53 LF OF NEW 4"DIA. PERFORATED DRAINPIPE TRENCH DRAIN PERDETAIL 1, SHT. C3.3CONNECT NEW 4" DIA. PERFPIPE TO EXST. CB 132700IE = 43.0'3' OFF ASPHALT EDGEIE = 43'CAP ENDIE = 43'CAP ENDIE = 43.0'UPON COMPLETION OF RETAININGWALLS, INSTALL ECBVERDYOL C32 BLONG TERM EROSION CONTROLBLANKET ON SLOPE BELOW WALL 1 ANDPLANTINGS PER LANDSCAPING PLAN.SEE DETAILS ON SHT. C3.3.SECTION A-A'SEE THIS SHEET3'5' (ȭ PILE TO ȭ PILE)WALL 2F.G. @ T.W. ELEV. 62.5'F.G. @ B.W. ELEV. 58.5'WALL 1F.G. @ T.W. ELEV. 58.5'F.G.@B.W. ELEV. 54.5' (MIN.)EXST. 1' TO 2'ROCKERY3' MIN.TOP OF SLOPE ~ ELEV. 62.5'EDGE OF PAVEMENTEXST. GRADE. INSTALL LONGTERM EROSION CONTROLBLANKET BELOW WALL 1 (TYP)SEE DETAILS ON SHT. C3.3PL5055606545SECTION A - A'EXISTING ROCKERYTO REMAINPIN PILE RET. WALL 2PIN PILE RET. WALL 1PROPOSED FLAT BENCHW/ PLANTINGS7' MIN.GALVANIZED 2 12 " DIA. XHA53 GRADE B PILES (TYP.)~5'INSTALL NEW PERFORATEDDRAIN PIPE PER THIS SHT.AND DETAIL 1, SHT. C3.31" = 5'*SEE ADDITIONALDETAILS ON SHTS.C3.1 - C3.24' MAX.4' MAX.3'3' MIN.45+ $&7,9(:('*(
PROPOSED 3' GENTLYSLOPING BENCH W/PLANTINGS7' MIN.PLAN VIEWDESIGNED:SCALE:CHECKED:DRAWN:DATE:SHEETJOB NO.OFBYDESCRIPTIONDATENO.PLOT DATE:DRAWING19019 36th Avenue West, Suite E |Lynnwood, WA 98036PH: (425) 582-9928 | Fax: (425) 582-9930 | www.zippergeo.comSUBMITTAL RECORD8/26/19LAST EDIT:RobZ:\Projects\2001 - 2050\2041 McCarthy Residence\2041.01 McCarthy Residence\Working File\Drafting\2041.01 Plans REV 3.dwgRAR4/25/19-INITIAL RELEASE6MCCARTHY RESIDENCE SLOPE STABILIZATION3403 BURNETT AVENUE NORTHRENTON, WASHINGTON8/8/192041.01TAJRARRARRAR7/25/19-REDESIGN W/PIN PILE WALLS - INITIAL RELEASE8/26/19RAR8/8/191REVISED PER CITY REVIEW COMMENTSRAR8/26/192REVISION TO ADDRESS PLANNING COMMENTSAS SHOWNAPPROXIAMTE SCALE IN FEET051010EXHIBIT 7DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
SECTION DETAILWALL 2PIN PILE RET. WALL 11' MIN.INSTALL MIRAFI G100WDRAINAGE COMPOSITE ONBACK FACE OF LAGGING PRIORTO BACKFILLING W/FILTERSIDE TOWARDS SOIL.PROVIDE 18" GAPBETWEEN LAGGING TOPROMOTE DRAINAGE.TUCK DRAINAGE FABRIC UNDERLAGGING AND EXTEND 6" MIN. BEYONDLAGGING FACE3' (TYP.)REMOVE AND REPLACE NATIVE SOILSWITH 1-14" CRUSHED ROCKBENCH CUT NATIVE SOILSPRIOR TO PLACING WALL 1BACKFILL1' (TYP.)NATIVE SOIL BACKFILLPLACED IN 6" LOOSE LIFTSAND COMPACTED WITHHAND-TAMPERPROVIDE 18" GAP BETWEEN LAGGING TOPROMOTE DRAINAGE. SEE WALL 2GAPPING DETAIL, THIS SHT.2"X10" TIMBERLAGGINGSTRIPS OF FOLDED MIRAFI 140N FILTERFABRIC SANDWICHED BETWEENLAGGING BOARDS18" LAGGING GAPGALVANIZED 2 12 " DIA. XHA53 GRADE B PILES (TYP.)2 X 10 PRESSURETREATED HEM-FIR NO. 2OR BETTER TIMBERLAGGING (TYP.)WALL 2 LAGGING GAP DETAIL6" MIN. THICKNESS 1-14"CRUSHED ROCK (TYP.)6" MIN. (TYP.)6" MIN. (TYP.)U-BOLTS (TYP.)COMPACT NATIVE SOIL SUBGRADE INFRONT OF WALL 26" (TYP.)6" (TYP.)2-1/2" SCHD. 80 CAP.ADHERE TO PILE USING ANAPPROPRIATE CONSTRUCTIONADHESIVE (TYP.)COMPRESSION FITTED SLEEVEDCOUPLERS (TYP.) COUPLERS SHALL BELOCATED AT LEAST 4 FEET BELOWFINISHED GRADE (TYP.)4' MIN.EROSION CONTROLBLANKETDESIGNED:SCALE:CHECKED:DRAWN:DATE:SHEETJOB NO.OFBYDESCRIPTIONDATENO.PLOT DATE:DRAWING19019 36th Avenue West, Suite E |Lynnwood, WA 98036PH: (425) 582-9928 | Fax: (425) 582-9930 | www.zippergeo.comSUBMITTAL RECORD8/26/19LAST EDIT:RobZ:\Projects\2001 - 2050\2041 McCarthy Residence\2041.01 McCarthy Residence\Working File\Drafting\2041.01 Plans REV 3.dwgRAR4/25/19-INITIAL RELEASE6MCCARTHY RESIDENCE SLOPE STABILIZATION3403 BURNETT AVENUE NORTHRENTON, WASHINGTON8/8/192041.01TAJRARRARRAR7/25/19-REDESIGN W/PIN PILE WALLS - INITIAL RELEASE8/26/19RAR8/8/191REVISED PER CITY REVIEW COMMENTSRAR8/26/192REVISION TO ADDRESS PLANNING COMMENTS-EXHIBIT 8DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
U-BOLT DETAIL3/8" (DIA.) X 3" (W) X 5-1/2" (L) (MIN)HOT DIPPED GALVANIZED U-BOLT(SIZED FOR 2-1/2" DIA. PIPE)3/8" GALVANIZED LOCK WASHER3/8" x 1" GALVANIZED FLAT WASHER~4-3/8"2X PT LAGGINGGALVANIZED NUTGALVANIZED 2 12 " DIA. XH A53 GRADE BPILES (TYP.)FINISHED GRADE ATBOTTOM OF WALLFINISHED GRADE AT TOP OFWALL2 X 10 PRESSURE TREATEDHEM-FIR NO. 2 OR BETTERTIMBER LAGGING (TYP.)FACE ON VIEW (TYP.)8" (TYP.)4' (TYP.)3' - 4" (TYP.)GALVANIZED 2 12 "DIA. XH A53 GRADEB PILES (TYP.)U-BOLTS (TYP.)MIRAFI DRAINAGE COMPOSITEBEHIND LAGGING (TYP. WALL 1ONLY)RETAINED SOIL / BACK OF WALLFACE OF WALL2 X 10 PRESSURE TREATED HEM-FIR NO.2 OR BETTER TIMBER LAGGING (TYP.) GALVANIZEDU-BOLT PER DETAIL3, THIS SHT.(TYP.)8" (TYP.)TOP VIEW (TYP.)3' - 4" (TYP.)4' (TYP.)GALVANIZED 2 12 " DIA. XH A53GRADE B PILES (TYP.)GENERAL NOTESDESIGN LOADS1.~43 PCF EQUIVALENT ACTIVE FLUID EARTH PRESSURE.SPECIAL INSPECTION1.SPECIAL INSPECTIONS ARE REQUIRED AS INDICATED IN THEFOLLOWING TABLE. THE CONTRACTOR SHALL SUBMIT AWRITTEN STATEMENT OF RESPONSIBILITY TO THE BUILDINGOFFICIAL AND OWNER PRIOR TO COMMENCEMENT OF WORKIN ACCORDANCE WITH CHAPTER 1704.4 OF THE IBC2.INSPECTION REPORTS SHALL BE PROVIDED FOR EACH DAYON SITE BY GEOTECHNICAL ENGINEER. REPORTS SHALL BEDISTRIBUTED TO THE CONTRACTOR AND BUILDING OFFICIAL.3.ALL ITEMS MARKED WITH AN "X" SHALL BE INSPECTED INACCORDANCE WITH IBC CHAPTER 17. SPECIAL INSPECTIONSHALL BE PERFORMED BY THE GEOTECHNICAL ENGINEER(ZIPPER GEO ASSOCIATES, LLC).PIPE PILES1.PIPE PILES SHALL BE 2-1/2 INCH DIAMETER XH A53 GRADE B(35 KSI YIELD STRENGTH).2.PIPE PILES SHALL BE HOT DIPPED GALVANIZED INACCORDANCE WITH ASTM A123 AT A MINIMUM APPLICATIONRATE OF 2 OZ./SF.3.GALVANIZATION DAMAGE SHALL BE REPAIRED INACCORDANCE WITH ASTM A780. REPAIRED AREAS SHALLHAVE A MINIMUM DRY FILM THICKNESS OF 4 MILS.4.PIPE PILES SHALL BE DRIVEN TO THE MINIMUM EMBEDMENTDEPTH AS SHOWN ON THE PLANS. PILES TO BE DRIVEN INNOMINAL SECTIONS AND CONNECTED WITH COMPRESSIONFITTED SLEEVED COUPLERS.STEEL HARDWARE1.STEEL HARDWARE INCLUDING UBOLTS, NUTS, AND WASHERSSHALL BE ASTM A307 GALVANIZED IN ACCORDANCE WITHASTM A153.TIMBER LAGGING1.TIMBER LAGGING SHALL BE 2 X 10 PRESSURE TREATEDHEM-FIR NO. 2 OR BETTER TIMBER. TREATMENT SHALL BE INACCORDANCE WITH AWPA USE CATEGORY UC4A. LAGGINGCUTOFFS SHALL BE FIELD-TREATED BY TWO LIBERALAPPLICATIONS OF A COPPER NAPHTHENATE PRESERVATIVE.THE APPLICATION SHALL BE PER AWPA STANDARD M4.OPERATIONCONT.PERIODICREMARKSPILE INSTALLATIONXGEOTECHENGINEERLAGGINGINSTALLATIONXGEOTECHENGINEEREXCAVATION ANDBACKFILLINGXGEOTECHENGINEEREROSION CONTROLXGEOTECHENGINEERDESIGNED:SCALE:CHECKED:DRAWN:DATE:SHEETJOB NO.OFBYDESCRIPTIONDATENO.PLOT DATE:DRAWING19019 36th Avenue West, Suite E |Lynnwood, WA 98036PH: (425) 582-9928 | Fax: (425) 582-9930 | www.zippergeo.comSUBMITTAL RECORD8/26/19LAST EDIT:RobZ:\Projects\2001 - 2050\2041 McCarthy Residence\2041.01 McCarthy Residence\Working File\Drafting\2041.01 Plans REV 3.dwgRAR4/25/19-INITIAL RELEASE6MCCARTHY RESIDENCE SLOPE STABILIZATION3403 BURNETT AVENUE NORTHRENTON, WASHINGTON8/8/192041.01TAJRARRARRAR7/25/19-REDESIGN W/PIN PILE WALLS - INITIAL RELEASE8/26/19RAR8/8/191REVISED PER CITY REVIEW COMMENTSRAR8/26/192REVISION TO ADDRESS PLANNING COMMENTS-DocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D
4" TOPSOIL4" DIA. PERFORATEDDRAINAGE PIPE WITHPERFORATIONS FACING DOWN2' (TYP.)2'1' MIN.MIRAFI 140N NON-WOVENGEOTEXTILEGRAVEL BACKFILL FORDRAINS PER SECTION9-03.12(4), WSDOT STANDARDSPECS.TRENCH DRAIN DETAIL1.Prepare soil before installing rolled erosioncontrol products (RECPs), including anynecessary application of lime, fertilizer, andseed.2.Begin at the top of the slope by anchoring theRECPs in a 6" deep X 6" wide trench withapproximately 12" of RECPs extendedbeyond the up-slope portion of the trench.Anchor the RECPs with a row ofstaples/stakes approximately 12" apart in thebottom of the trench. Backfill and compactthe trench after stapling. Apply seed to thecompacted soil and fold the remaining 12"portion of RECPs back over the seed andcompacted soil. Secure RECPs overcompacted soil with a row ofstaples/stakes spaced approximately 12"apart across the width of the RECPs.3.Roll the RECPs (A) down or (B) horizontallyacross the slope. RECPs will unroll withappropriate side against the soil surface. AllRECPs must be securely fastened to soilsurface by placing staples/stakes inappropriate locations as shown in the staplepattern guide.4.The edges of parallel RECPs must be stapledwith approximately 2" - 5" overlap dependingon the RECPs type.5.Consecutive RECPs spliced down the slopemust be end over end (Shingle style) with anapproximate 3" overlap. Staple throughoverlapped area, approximately 12" apartacross entire RECPs width.2"-5"3B42513A12"6"6"3"ANCHORAGE DEVICES SHALLCONSIST OF 12" WOOD ECOSTAKES OR TL-TA1 12" TWISTPINS. INSTALL INACCORDANCE WITHMANUFACTURER'SRECOMMENDATIONS.EROSION CONTROL BLANKET INSTALLATIONEROSION CONTROL BLANKET ANCHORAGENOTE: INSTALL EROSION CONTROL BLANKET, PLANTING, ANDSEEDING IN ACCORDANCE WITH ECB MANUFACTURER'SRECOMMENDATIONS.DESIGNED:SCALE:CHECKED:DRAWN:DATE:SHEETJOB NO.OFBYDESCRIPTIONDATENO.PLOT DATE:DRAWING19019 36th Avenue West, Suite E |Lynnwood, WA 98036PH: (425) 582-9928 | Fax: (425) 582-9930 | www.zippergeo.comSUBMITTAL RECORD8/26/19LAST EDIT:RobZ:\Projects\2001 - 2050\2041 McCarthy Residence\2041.01 McCarthy Residence\Working File\Drafting\2041.01 Plans REV 3.dwgRAR4/25/19-INITIAL RELEASE6MCCARTHY RESIDENCE SLOPE STABILIZATION3403 BURNETT AVENUE NORTHRENTON, WASHINGTON8/8/192041.01TAJRARRARRAR7/25/19-REDESIGN W/PIN PILE WALLS - INITIAL RELEASE8/26/19RAR8/8/191REVISED PER CITY REVIEW COMMENTSRAR8/26/192REVISION TO ADDRESS PLANNING COMMENTSNOT TO SCALEDocuSign Envelope ID: 0D1121B7-5E71-4804-AD94-A71D8156DC6D