HomeMy WebLinkAboutERC Report_Kennydale Lakeline Assessment_180521.pdfDEPARTMENT OF COMMUNITY
AND ECONOMIC DEVELOPMENT
Project Location Map
ERC Report_Kennydale Lakeline AssessmentKennydale Lakeline Assessment
ENVIRONMENTAL REVIEW COMMITTEE REPORT
ERC MEETING DATE: May 21, 2018
Project Name: Kennydale Lakeline Assessment
Project Number: PR18-000184
Land Use Permit
Number:
LUA18-000277, ECF, SME
Project Manager: Clark H. Close, Senior Planner
Applicant/Contact: David Christensen, Wastewater Utility Manager / City of Renton /
dchristensen@rentonwa.gov / 1055 S Grady Way 5th Fl. Renton, WA 98057
Project Location: Renton Kennydale Area. Along Lake Washington from approximately 2725
Mountain View Ave N (APN 0623059005) to 3905 Lake Washington Blvd N
(APN 3342700011).
Project Summary: The applicant is requesting a Shoreline Exemption and Environmental (SEPA)
Review to evaluate the condition of the Kennydale Lakeline Sewer System.
During the 2018 summer fish window, the project proposes to allow the City
of Renton Wastewater Utility to complete a physical inspection of the pipe,
perform pipe sampling, install manholes, and complete pipe cleaning in and
along Lake Washington to determine what is needed to properly maintain the
system and evaluate replacement options. The results of the evaluation
would determine the remaining useful life of the system and may result in
recommendations for future improvements. The pipeline evaluation and
associated work would be located in Lake Washington Reach E, in select areas
with moderate landslide hazards, and in an area with potential cultural
resources. Coordination with property owners is anticipated with the work.
Exist. Bldg. Area SF: N/A Proposed New Bldg. Area (footprint):
Proposed New Bldg. Area (gross):
None
None
Site Area: N/A Total Building Area to Remain GSF: N/A
STAFF
RECOMMENDATION:
Staff Recommends that the Environmental Review Committee issue a
Determination of Non-Significance (DNS).
Lake Washington
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
City of Renton Department of Community & Economic Development Environmental Review Committee Report
KENNYDALE LAKELINE ASSESSMENT LUA18-000277, ECF, SME
Report of May 21, 2018 Page 2 of 7
ERC Report
PART ONE: PROJECT DESCRIPTION / BACKGROUND
The applicant, City of Renton Wastewater Utility Systems, is requesting a Shoreline Exemption and
Environmental (SEPA) Review to assess the condition of the Kennydale Lakeline Sewer System (KLSS). The
sewer line is located in the Residential-8 zone in Lake Washington (Exhibit 2). This maintenance project is
intended to complete a physical inspection of the sewer pipeline at up to thirteen (13) locations to
determine what is needed to properly maintain the system and evaluate replacement options. Condition
evaluation would include ultrasonic thickness testing at five (5) locations, pipe sampling via the collection
of a single coupon on the mainline, collection of up to three (3) coupons on lateral lines, and temporary
access to two (2) existing manholes for lake line cleaning. Two (2) additional locations would be accessed,
pipe sections would be removed for evaluation, and the section would be replaced with manh oles below
grade. The project locations are aquatic and all work would be staged from a floating barge and/or boat.
Divers would be deployed from the barge/boat to expose the sewer lake line and conduct maintenance
activities.
In general, the work plan would involve the installation of site isolation best management practices
(BMPs), followed by placement of a shoring system, if required, and pipeline excavation using a suction
dredge. Once the pipeline is exposed the pipeline would be evaluated and sedi ment sampling or
corrosion/thickness measurement may occur. Depending on the location, one of three types of actions
would occur at this point: either 1) a pipeline sample or coupon would be removed for corrosion and
thickness testing and repaired with compression fitting; 2) ultrasonic pipeline thickness testing; or 3) a
section of pipeline would be removed for testing, and replaced with a manhole. These coupons, collected
from several locations, would provide valuable information on the condition of the lake line pipe. One
coupon would be collected near 3703 Lake Washington Blvd N. This coupon is at a relatively high elevation
along the lake line that is more likely to have been exposed to corrosive atmosphere. Additional coupons
would also be collected on laterals in front of 2905 Mountain View Ave N, 3107 Mountain View Ave N, and
3703 Lake Washington Blvd N. Pipeline sampling at these locations may also impact the adjacent
properties at 2909 Mountain View Ave N and 3103 Mountain View Ave N (Exhibits 3 and 4). These laterals
are also at relatively high elevations along the lake line and experience intermittent gas exposure . These
coupons would supply information about pipe corrosion under adverse conditions. The results of the
evaluation would aid in formulating a conservative estimate of the remaining useful life and vulnerability
of the system and may result in recommendations for future improvements. Following pipeline repair, the
substrate would be returned to pre-construction conditions and BMPs would be removed. No substantial
changes would be made to the overall structure or layout of the pipeline and all elements would be below
final grade.
The KLSS was originally constructed in 1972 to provide sanitary sewer service to approximately 55 to 60
lakefront homes along Lake Washington from the north end of Gene Coulon Memorial Beach Park to just
south of May Creek. The pipeline evaluation and associated work would be located in Lake Washington
Reach E, in select areas with moderate landslide hazards, and in an area with potential cultural resources.
The proposed work follows the Phase 2A of the Lake Line Condition Assessment which included ultrasonic
thickness testing and visual inspection of exposed portions of the lake line as well as survey, bulkhead
assessment and hydraulic assessment. As part of the hydraulic assessment it was concluded that the
hydraulic capacity of the lake line is reduced, indicative of partial blockages in two general areas. These
partial blockages are likely the result of solids settlement caused by velocities below those needed for self -
cleaning. Current access from the shoreline for cleaning is limited, and settled solids cannot effectively be
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
City of Renton Department of Community & Economic Development Environmental Review Committee Report
KENNYDALE LAKELINE ASSESSMENT LUA18-000277, ECF, SME
Report of May 21, 2018 Page 3 of 7
ERC Report
removed using the shore-based cleaning protocol. Therefore to address these partial blockages, it is
proposed that three (3) existing submerged manholes on the lake line be temporarily accessed for
cleaning. Temporary access from the lake surface would be obtained with steel riser sections connected to
the manhole structure.
Once accessed, wastewater from the manholes and adjacent sections of the lake line would be removed
prior to cleaning. It is proposed that the cleaning process would use a jetter hose to flush solids toward the
manhole where they would be removed by a vacuum. Closed circuit television (CCTV) inspection would be
performed before and after cleaning to evaluate the effectiveness of the cleaning procedure. Properties at
2827, 2909, 3111, and 3119 Mountain View Ave N, would experience short-term construction impacts due
to their proximately to the manhole location. The two (2) new proposed manholes would be at low points
along the undulating sewer to facilitate solids removal. Their locations would facilitate cleaning of a partial
blockage believed to be impacting the southern portion of the pipe. The three (3) existing submerged
manholes would be used to clean the northern blockage. The proposed manholes would be buried to
comply with anticipated permit requirements.
Flexible couplings would be installed on the lake line approximately 10 feet from the manhole to enable
localized lowering of the sewer profile and ensure that the manhole cover is below the lakebed. This would
allow the manholes to be installed without permanently modifying the lakebed, which would trigger a
more intensive permitting process and likely preclude this work from being performed in this summer. The
proposed work would be conducted between July 16, 2018 and September 30, 2018 (work windows for
fish protection for Lake Washington) and would include a condition assessment on parts of the pipe not
currently exposed. This assessment would enable additional analyses of the pipe material to determine the
amount of corrosion and remaining useful life of the pipe to aid in the City’s strategic planning process.
A summary of the work plan includes the following steps:
1. Surround the work area with a floating silt curtain, starting with a collapsed curtain and expanding
it so as to eliminate fish from the work area. Once expanded to enclose the work area, the bottom
of the silt curtain would be anchored to the lake bed with sandbags at four foot intervals. The
curtain would remain in place throughout the work and for a sufficient period after the work to
allow the vast majority of sediments to settle.
2. Conduct turbidity monitoring adjacent to the work zone before, during, and after the work. Results
would be documented and any noted exceedances would lead to a) adjustment of work practices,
or b) stoppage of the work until suitable adjustments can be made.
3. Place a shoring box along the pipeline surrounding the excavation zone. The shoring box would
settle down to the base of the excavation as the work progresses.
4. Expose the buried pipeline by suction dredging within the shoring system. Dredging would be
conducted using a boat/barge‐mounted trash pump. Excavated materials would be placed outside
the shoring but within the silt curtain perimeter.
5. Reduced water usage would be requested of home owners adjacent to the sewer prior t o
commencement of work. Flush the pipeline with municipal water to remove most of the sewage
prior to cutting the pipe.
6. Cut a 4‐6‐inch diameter hole from the pipe for thickness and corrosion testing. Seal the hole with a
pipe repair coupling.
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
City of Renton Department of Community & Economic Development Environmental Review Committee Report
KENNYDALE LAKELINE ASSESSMENT LUA18-000277, ECF, SME
Report of May 21, 2018 Page 4 of 7
ERC Report
7. Cut through the pipe at the downstream end of the work zone and place a plate to seal the
downstream pipe from excessive lake water intrusion. Cut through the pipe at the upstream end of
the work zone and removing the existing pipe between the cuts.
8. Replace the removed pipe section with a new pipe segment that includes a manhole to facilitate
future cleaning operations. The manholes would be left below the lake bed (Exhibit 5). Install repair
couplings to join and seal the replacement segment to the existing pipeline.
9. Return the sewer system to normal operation. Check for leaks and ensure KLSS is functioning
properly.
10. Suction dredge excavated materials back into the excavation zone while removing the shoring
system. Shovel/rake/hydrojet finished surface to original grade .
11. Wait until sediments have settled from the work area before removing the floating silt curtain.
Several permits would be required for either maintenance of the existing line or for conducting a
conditions assessment for the existing line, which would include in-water work and disturbance of the
lakebed. The following other government approvals/permits would be required: US Army Corp of
Engineers (“Corps”) permit to meet requirements of the Rivers and Harbors Act Section 10 and Section 404
of the Clean Water Act, Hydraulic Project Approval (HPA) for projects located near or within a Water of the
State, Section 401 Water Quality Certification from Washington State Department of Ecology (“Ecology”)
(possibly required), and Hydraulic Project Approval (HPA) from Washington Department of Fish & Wildlife
(WDFW). The Joint Aquatic Resource Permit Application (JARPA) process is used to request the HPA, CWA
Section 401 Certification, Section 404, and Section 10 permits. Issuance of Section 404 and Section 10
permits by the Corps is contingent on completion of the National Environmental Policy Act (NEPA) and the
federal Endangered Species Act (ESA) processes. Additional SEPA review is anticipated for future
improvements, maintenance, or replacement of the Kennydale system after the scope and schedule for
those improvements are known.
PART TWO: ENVIRONMENTAL REVIEW
In compliance with RCW 43.21C.240, the following environmental (SEPA) review addresses only those
project impacts that are not adequately addressed under existing development standards and
environmental regulations.
A. Environmental Threshold Recommendation
Based on analysis of probable impacts from the proposal, staff recommends that the Responsible
Officials:
Issue a DNS with a 14-day Appeal Period.
B. Exhibits
Exhibit 1 ERC Report
Exhibit 2 Location Map
Exhibit 3 Vicinity Map
Exhibit 4 Location Reference Table
Exhibit 5 Lake Line Manhole Plans
Exhibit 6 Environmental Conditions Report
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
City of Renton Department of Community & Economic Development Environmental Review Committee Report
KENNYDALE LAKELINE ASSESSMENT LUA18-000277, ECF, SME
Report of May 21, 2018 Page 5 of 7
ERC Report
C. Environmental Impacts
The proposal was circulated and reviewed by various City Departments and Divisions to determine
whether the applicant has adequately identified and addressed environmental impacts anticipated to
occur in conjunction with the proposed development. Staff reviewers have identified that the proposal
is likely to have the following probable impacts:
1. Earth
Impacts: The project site is located in Lake Washington, waterward of the Ordinary High Water
Line. The KLSS corridor is approximately 4,800 linear feet (Exhibit 6). The shoreline in the proposed
work area runs primarily parallel to the highly modified shoreline, approximately 4,500 linear feet.
The shoreline consists of riprap, gabion walls, vertical bulkheads, gravel beaches from south of
Coleman Point, at the Lake Washington Flush Station, north to May Creek. Overwater structures
include docks associated with single-family residences and a log boom delineating the designated
swimming area at Kennydale Beach Park.
The adjacent uplands are residential, relatively flat and rolling. Slopes along the shoreline range
from flat (less than 15 percent slope) to gently or moderately sloping (less than 40 percent slopes),
with a majority of the shoreline having 15 to 25 percent slopes. Slopes in each project location are
less than 1 percent, indicating low risks to the existing moderate landslide hazards. The project is
not located near steep slopes and would not affect steep slopes. The bathymetry of the lake is
gradual in the project vicinity with water depths between 6 and 20 feet.
The sediment characteristics underlying the water along the vessel routes in the study area include
sand, gravel, and cobble, along with various combinations of these sediment types. Excavation
would be limited to the volumes sufficient to expose the sewer pipe. Excavated areas would be no
larger than 20 feet wide by 36 feet long by 6 feet deep. Up to approximately 279 cubic yards of
material may be excavated. The applicant estimates between 5 and 234 cubic yards of excavation
depending upon the activity proposed at each site. Material would be stockpile d inside the floating
turbidity curtain. After completing inspection and repair at each location, excavated sediments
would be used to return the lakebed to its original grade.
According to the applicant, no erosion is expected as a result of this project. Excavation and site
restoration would occur over approximately five (5) working days at each location. A sediment
curtain would be used to prevent material from being discharged beyond the project site.
Excavation would be limited to the smallest amount necessary to expose the pipe and conduct
inspections and/or make repairs.
Mitigation Measures: No further mitigation recommended.
Nexus: N/A
2. Air
Impacts: It is anticipated that some temporary air quality impacts associated with the assessment
and excavation work of the KLSS would occur. The project would require a work barge/boat which
includes water‐jetting or suction dredge to perform underwater excavation. Emissions from project
construction would be limited to roughly three (3) gasoline generators during daily operations plus
outboard boat engines for site access and environmental monitoring during operations.
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
City of Renton Department of Community & Economic Development Environmental Review Committee Report
KENNYDALE LAKELINE ASSESSMENT LUA18-000277, ECF, SME
Report of May 21, 2018 Page 6 of 7
ERC Report
Upstream sewage would be diverted to Pump Station #14 wet well for storage and the pipeline
would be flushed with freshwater prior to commencing with the work. This would ensure that no
sewer gases are released into the environment. Should the work take long enough to fill the wet
well, Vactor vacuum trucks would be available to empty the wet well and dispose of the sewage in
another sewer service area. This would ensure that no waste would enter Lake Washington.
Maintenance of the equipment to meet State and Federal air quality requirements would serve to
mitigate the potential adverse impacts. No further site specific mitigation for the identified impacts
from typical vehicle and construction exhaust is required.
Mitigation Measures: No further mitigation recommended.
Nexus: N/A
3. Environmental Health
a. Environmental Health Hazards
Impacts: The project would include removing coupons from the sewer pipeline for testing. Best
management practices related to the handling and storage of any environmental health hazards
would be implemented during the sewer line inspection to avoid and minimize any potential
hazards. The workers’ health would be protected during demolition activities by applicable
regulations regarding removal of hazardous materials from Washington State Department of Labor
and Industries, the Environmental Protection Agency and the Washington State Department of
Ecology.
Mitigation Measures: No further mitigation recommended.
Nexus: N/A
b. Noise
Impacts: Temporary, short-term impacts are anticipated from transit to and from the inspection
site from outboard engines, the operation of water jet/suction dredge equipment, and generators
required to operate the equipment or compressors providing air to underwater workers. Project-
related noise is anticipated to attenuate to background levels within 283 feet of the project. No
changes to noise levels would occur following the completion of the project. The equipment noise
would be regulated through the City’s adopted noise level regulations per Chapter 8 -7, RMC.
Permitted work hours in or near residential areas are restricted to the hours between seven o’clock
(7:00) a.m. and eight o’clock (8:00) p.m. Monday through Friday. Work on Saturdays is restricted to
the hours between nine o’clock (9:00) a.m. and eight o’clock (8:00) p.m. No work is permitted on
Sundays. The applicant indicated that all the construction noise impacts are anticipated to occur
during daylight hours. No unusual noise impacts are proposed, which would require further levels
of mitigation.
Mitigation Measures: No further mitigation recommended.
Nexus: N/A
4. Aesthetics
Impacts: During inspection and repair activities, a barge/boat would be located at the site. These
vessels would not be higher than 10 feet above the water level and would be onsite for up to five
(5) days at each location. Upon completion, all structures and repair work on the sewer pipeline
would be buried below grade in the bed of Lake Washington.
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
City of Renton Department of Community & Economic Development Environmental Review Committee Report
KENNYDALE LAKELINE ASSESSMENT LUA18-000277, ECF, SME
Report of May 21, 2018 Page 7 of 7
ERC Report
Mitigation Measures: No further mitigation recommended.
Nexus: N/A
5. Historic and Cultural Preservation
Impacts: In the SEPA Checklist (“Checklist”), the applicant indicated that there are no historic
structures or sites present in the project area. However, historic and pre-historic settlements are
known to have existed around Lake Washington. The proposed excavation, maintenance and repair
activity would be limited to the disturbance area of the already buried pipeline within the lake bed.
Probes would be used to confirm the pipe’s location prior to excavation. The Checklist concludes
that because the pipeline was installed in 1972, all relevant lake sediments have been considered
previously disturbed and thus the applicant is not anticipating the discovery of any historic artifacts
in the anticipated area of excavation. If any historic or archaeological resources are encountered
during implementation of maintenance activities, work would be stopped in accordance with RCW
27.53.060 and 27.44.020 and a professional archaeologist would be called to assess the significance
of the find.
No comments were received from the Washington State Department of Archeology and Historic
Preservation.
Mitigation Measures: No further mitigation recommended.
Nexus: N/A
D. Comments of Reviewing Departments
The proposal has been circulated to City Department and Division Reviewers. Where applicable, their
comments have been incorporated into the text of this report.
Copies of all Review Comments are contained in the Official File and may be attached to this
report.
The Environmental Determination decision will become final if the decision is not appealed within the
14-day appeal period (RCW 43.21.C.075(3); WAC 197-11-680).
Environmental Determination Appeal Process: Appeals of the environmental determination must be
filed in writing together with the required fee to: Hearing Examiner, City of Renton, 1055 South Grady
Way, Renton, WA 98057, on or before 5:00 p.m. on June 8, 2018. RMC 4-8-110 governs appeals to the
Hearing Examiner and additional information regarding the appeal process may be obtained from the City
Clerk’s Office, Renton City Hall – 7th Floor, (425) 430-6510.
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
DEPARTMENT OF COMMUNITY
AND ECONOMIC DEVELOPMENT
ENVIRONMENTAL (SEPA) DETERMINATION OF NON-SIGNIFICANCE (DNS)
PROJECT NUMBER: LUA18-000277, ECF, SME
APPLICANT: David Christensen / (425) 430-7212 / 1055 Grady S Way, Renton,
WA 98057
PROJECT NAME: Kennydale Lakeline Assessment
PROJECT DESCRIPTION: The applicant is requesting a Shoreline Exemption and
Environmental (SEPA) Review to evaluate the condition of the Kennydale Lakeline Sewer System (KLSS).
During the 2018 summer fish window, the project proposes to allow the City of Renton Wastewater
Utility to complete a physical inspection of the pipe, perform pipe sampling, install manholes, and
complete pipe cleaning along Lake Washington to determine what is needed to properly maintai n the
system and evaluate replacement options. The results of the evaluation would determine the remaining
useful life and vulnerability of the system and may result in recommendations for future improvements.
The KLSS was originally constructed in 1972 to provide sanitary sewer service to approximately 55 to 60
lakefront homes along Lake Washington from the north end of Gene Coulon Memorial Beach Park to
just south of May Creek. The pipeline evaluation and associated work would be located in Lake
Washington Reach E, areas of moderate landslide hazards and in an area of potential cultural resources.
Coordination with property owners is anticipated as part of the work. The applicant submitted an
Environmental Conditions Report with the application.
PROJECT LOCATION: Renton Kennydale Area. Along Lake Washington from approximately
2725 Mountain View Ave N (APN 0623059005) to 3905 Lake Washington
Blvd N (APN 3342700011).
LEAD AGENCY: City of Renton
Environmental Review Committee
Department of Community & Economic Development
The City of Renton Environmental Review Committee has determined that it does not have a probable
significant adverse impact on the environment. An Environmental Impact Statement (EIS) is not required under
RCW 43.21C.030(2)(c). This Determination of Non-Significance is issued under WAC 197-11-340. Because other
agencies of jurisdiction may be involved, the lead agency will not act on this proposal for fourteen (14) days.
Appeals of the environmental determination must be filed in writing on or before 5:00 p.m. on June 8, 2018.
Appeals must be filed in writing together with the required fee with: Hearing Examiner, City of Renton, 1055
South Grady Way, Renton, WA 98057. Appeals to the Examiner are governed by RMC 4-8-110 and more
information may be obtained from the Renton City Clerk’s Office, (425) 430-6510.
PUBLICATION DATE: MAY 25, 2018
DATE OF DECISION: JUNE 8, 2018
SIGNATURES:
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
DEPARTMENT OF COMMUNITY
AND ECONOMIC DEVELOPMENT
Gregg Zimmerman, Administrator
Public Works Department
Date Rick M. Marshall, Administrator
Renton Regional Fire Authority
Date
Kelly Beymer, Administrator
Community Services Department
Date C.E. “Chip” Vincent, Administrator
Department of Community &
Economic Development
Date
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
5/17/2018 | 1:32 PM PDT
5/17/2018 | 1:37 PM PDT
5/17/2018 | 2:02 PM PDT
5/17/2018 | 1:13 PM PDT
Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS,AeroGRID, IGN, and the GIS User Community
FIGURE 1LOCATION MAP
REFERENCE N UMBER:APPLICANT NAME: City of Renton, WAPROPOSED PRO JECT: Install manh oles, collect pipe coupon s, a nd p erform ultrasonic thickness testing on sewer lake line.LOCATION: Lake Wash ington b etwee n2727 Moun tain Vie w Ave N and 3903 LakeWashington Blvd N, Renton, WA 98056SHEET 1 OF 7DATE: 1 -3 1-2018
LAKE WASHINGTON
CITY OF RENTON
CITY OF MERCER ISLAND
±
PROJECT LOCATION
0 1,600 3,200800Feet
EXHIBIT 2
RECEIVED
04/20/2018 cclose
PLANNING DIVISION
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
Ú 1+002+003+004+005+006+007+008+009+0010+0011+001 2 +0 0 13+00
14+00
15+00
16+00
17+00 18+00 19+00
20+00
21+00
22+00
23+00 24+00
25+00
26+00 27+00 28+00 29+00%,%,")")Lake WashingtonFlush Station
ColemanPoint
30032931Site 3 Manhole
Site 2 Manhole
222811
2807
28052801
3013
3233
3111
3015 3107
3205
2909
2827
3209
3011
3213
2731
3103 3115
2727
3217
2815
3119
3101
2905
3307
30093007
3001
3005
N 30t
h StBurnett A v e N N 31s
t
StN 29t
h St N 32nd St N 33
r
d
St
L a k e W a s h in g to n B lv d N
M ountain View A ve N
0 200 400100Feet
FIGURE 2VICINITY MAP
±
Legend
")Ultrasonic Thickness Testing
%,Lateral Coupon
New Manhole
REFERENCE N UMBER:APPLICANT NAME: City of Renton, WAPROPOSED PRO JECT: Install manh oles, collect pipe coupon s, a nd p erform ultrasonic thickness testing on sewer lake line.LOCATION: Lake Wash ington b etwee n2727 Moun tain Vie w Ave N and 3903 LakeWashington Blvd N, Renton, WA 98056SHEET 2 OF 7DATE: 1 -3 1-2018
Lake Washington
OHWM
EXHIBIT 3
Ultrasonic Thickness Testing
Area of Impact:900 SF
Volume of Excavation:5 CY
Volume of Fill:5 CY
Ultrasonic Thickness Testing
Area of Impact:900 SF
Volume of Excavation:5 CY
Volume of Fill:5 CY
Pipe Coupon
Area of Impact:900 SF
Volume of Excavation:5 CY
Volume of Fill:5 CY
Pipe Coupon
Area of Impact:900 SF
Volume of Excavation:5 CY
Volume of Fill:5 CY
New Manhole
(See Figure 5)
Area of Impact:3,600 SF
Volume of Excavation:117 CY
Volume of Fill:113 CY
New Manhole
(See Figure 5)
Area of Impact:3,600 SF
Volume of Excavation:117 CY
Volume of Fill:113 CY
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
Ú%,")")")Kennydale Beach Park
Lake Washington #2Lift Station
CO585
2Site 1 Manhole
3909
37193613
36193611 3703 3717360537153711
3821
3625
3825 3837
3805
3901
3979
3601 37073607
37133709
3815
3811340535013307
3905
3827
3401
3411
3903Lake Washington Blvd N
0 200 400100Feet
FIGURE 3VICINITY MAP
Legend
MainlineCoupon
")Ultrasonic Thickness Testing
%,Lateral Coupon
±
REFERENCE N UMBER:APPLICANT NAME: City of Renton, WAPROPOSED PRO JECT: Install manh oles, collect pipe coupon s, a nd p erform ultrasonic thickness testing on sewer lake line.LOCATION: Lake Wash ington b etwee n2727 Moun tain Vie w Ave N and 3903 LakeWashington Blvd N, Renton, WA 98056SHEET 3 OF 7DATE: 1 -3 1-2018
Lake Washington
OHWM
Pipe Coupon
Area of Impact:900 SF
Volume of Excavation:5 CY
Volume of Fill:5 CY
Pipe Coupon
Area of Impact:900 SF
Volume of Excavation:5 CY
Volume of Fill:5 CY
Ultrasonic Thickness Testing
Area of Impact:900 SF
Volume of Excavation:5 CY
Volume of Fill:5 CY
Ultrasonic Thickness Testing
Area of Impact:900 SF
Volume of Excavation:5 CY
Volume of Fill:5 CY
Ultrasonic Thickness Testing
Area of Impact:900 SF
Volume of Excavation:5 CY
Volume of Fill:5 CY
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
Work Performed Approximate
Latitude/Longitude
Parcels Impacted Addresses
Manhole Installation
47.517663,-122.210646
3342103985 2905 Mountain View Ave N
3342103953 2909 Mountain View Ave N
3342104009 2827 Mountain View Ave N
47.519782,-122.210761
3342103860 3111 Mountain View Ave N
3342103855 3115 Mountain View Ave N
3342103845 3119 Mountain View Ave N
Main Line Coupon 47.524637,-122.207548 3342700270 3703 Lake Washington Blvd N
Lateral Coupon
47.517816,-122.210748 3342103985 2905 Mountain View Ave N
3342103953 2909 Mountain View Ave N
47.519402,-122.210915 3342103890 3103 Mountain View Ave N
3342103880 3107 Mountain View Ave N
47.524635,-122.207415 3342700270 3703 Lake Washington Blvd N
Ultrasonic Thickness Testing
47.519149,-122.211466 3342103895 3101 Mountain View Ave N
47.520493,-122.210316 3342103805 3213 Mountain View Ave N
47.521603,-122.208914 3124059077 3307 Lake Washington Blvd N
47.522364,-122.208507 3124059076 3401 Lake Washington Blvd N
47.523563,-122.207942 3342103580 3501 Lake Washington Blvd N
REFERENCE NUMBER:
APPLICANT NAME: City of Renton, WA
PROPOSED PROJECT: Install manholes, collect pipe
coupons, and perform ultrasonic thickness testing
on sewer lake line.
LOCATION: Lake Washington between 2727
Mountain View Ave N and 3903 Lake
Washington Blvd N, Renton, WA 98056
SHEET 4 OF 7
DATE: 1-31-2018
Figure 4
Location Reference Table
EXHIBIT 4
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
SILT CURTAIN
(EXTENT OF SILT CURTAIN
NOT SHOWN TO SCALE)
8" DI SANITARY
SEWER (TYP)
24" DIA. MANHOLE LID
48" DIA. RISER
LIMITS OF EXCAVATION
48" DIA. MANHOLE
10'
A
A
LAY BOTTOM OF SILT CURTAIN FLAT AND SECURE
WITH SANDBAGS SPACED MAXIMUM 4 FT ON
CENTER (TYP ENTIRE PERIMETER)
B
36'
PIPE REPAIR
CLAMP (TYP)
FLEXIBLE
COUPLING (TYP)
B 19'-6"1/31/2018 5:10:43 PM - P:\01621\135-01621-16001\CAD\SHEETFILES\MANHOLE FIGURES\FIGURE 5 - LAKE LINE MANHOLE PLAN.DWG - COLBY, ANDYwww.tetratech.com
Copyright: Tetra TechFIGURE 5
CITY OF RENTON
LAKE LINE MANHOLE
PLAN
1420 FIFTH AVENUE, SUITE 600
SEATTLE, WA 98101
206.883.9300
REFERENCE NUMBER:
APPLICANT NAME: City of Renton
PROPOSED PROJECT: Install manholes, collect
pipe coupons, and perform ultrasonic thickness
testing on sewer lake line.
LOCATION: Lake Washington between 2727
Mountain View Ave N and 3903 Lake Washington
Blvd N, Renton, WA 98056
SHEET 5 OF 7
DATE: 1-31-2018 N10'5'20'0
EXHIBIT 5
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
48"
24"
48"
12"
SILT
CURTAIN
(EXTENT OF
SILT CURTAIN
NOT SHOWN
TO SCALE)5'-9"LIMITS OF
EXCAVATION
TEMPORARY RISER
ORIGINAL GRADE
BACKFILLED WITH NATIVE
SEDIMENT AND 6" SPAWNING
GRAVEL
12"
1:1 SLOPE
8" DI SANITARY
SEWER
LAY SILT CURTAIN
FLAT TO BOTTOM,
SECURE WITH
SAND BAGS
19'-6"1/31/2018 5:20:23 PM - P:\01621\135-01621-16001\CAD\SHEETFILES\MANHOLE FIGURES\FIGURE 6 - LAKE LINE MANHOLE SECTION AA.DWG - COLBY, ANDYwww.tetratech.com
Copyright: Tetra TechFIGURE 6
CITY OF RENTON
LAKE LINE MANHOLE
SECTION A-A
1420 FIFTH AVENUE, SUITE 600
SEATTLE, WA 98101
206.883.9300
REFERENCE NUMBER:
APPLICANT NAME: City of Renton
PROPOSED PROJECT: Install manholes, collect
pipe coupons, and perform ultrasonic thickness
testing on sewer lake line.
LOCATION: Lake Washington between 2727
Mountain View Ave N and 3903 Lake Washington
Blvd N, Renton, WA 98056
SHEET 6 OF 7
DATE: 1-17-2018
4'2'8'0
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
48"
24"
48"
12"
LAY SILT CURTAIN FLAT TO BOTTOM,
SECURE WITH SAND BAGS
8" DI SANITARY
SEWER
5'-9"LIMITS OF
EXCAVATION 54"39"TEMPORARY RISER
FLEXIBLE
COUPLING (TYP)
10'
PIPE REPAIR
COUPLING (TYP)
ORIGINAL GRADE
BACKFILLED WITH NATIVE
SEDIMENT AND
6" SPAWNING GRAVEL
SILT
CURTAIN
(EXTENT OF
SILT CURTAIN
NOT SHOWN
TO SCALE)
36'
1:1 SLOPE~4'1/31/2018 5:21:53 PM - P:\01621\135-01621-16001\CAD\SHEETFILES\MANHOLE FIGURES\FIGURE 7 - LAKE LINE MANHOLE SECTION BB.DWG - COLBY, ANDYwww.tetratech.com
Copyright: Tetra TechFIGURE 7
CITY OF RENTON
LAKE LINE MANHOLE
SECTION B-B
1420 FIFTH AVENUE, SUITE 600
SEATTLE, WA 98101
206.883.9300
0 4'8'16'
REFERENCE NUMBER:
APPLICANT NAME: City of Renton
PROPOSED PROJECT: Install manholes, collect
pipe coupons, and perform ultrasonic thickness
testing on sewer lake line.
LOCATION: Lake Washington between 2727
Mountain View Ave N and 3903 Lake Washington
Blvd N, Renton, WA 98056
SHEET 7 OF 7
DATE: 1-31-2018 NDocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7
146 N Canal St, Suite 111 • Seattle, WA 98103 • www.confenv .com
Kennydale Lakeline Sewer System
ENVIRONMENTAL CONDITIONS REPORT
Prepared for:
City of Renton
April 6, 2017
EXHIBIT 6
RECEIVED
04/20/2018 cclose
PLANNING DIVISION
DocuSign Envelope ID: 8B83E200-7C11-4E8B-9FE2-30698BBA26C7