HomeMy WebLinkAboutBoeing-Renton_Apron-R_Year-1-Report (1).pdf
Exeltech Consulting, Inc.
8729 Commerce Place Drive NE
Lacey, Washington 98516
Prepared for
The Boeing Company
Renton, Washington
Year 1 Monitoring Report
Apron R Infrastructure Maintenance and Repair
Project
NWS-2017-37
Renton, Washington
December 19, 2024
Exeltech Consulting, Inc.
Apron R Infrastructure Maintenance and Repair Project Renton, WA
NWS-2017-37 i December 19, 2024
TABLE OF CONTENTS
Page
1.0 PROJECT OVERVIEW ....................................................................................................................... 1-1
1.1 USACE Reference Number .................................................................................................. 1-2
1.2 Responsible Parties ............................................................................................................ 1-2
1.3 Summary of Site Activities .................................................................................................. 1-2
2.0 MONITORING PROGRAM ............................................................................................................... 2-3
2.1 Performance Standards ...................................................................................................... 2-4
3.0 YEAR 1 MONITORING RESULTS ...................................................................................................... 3-1
3.1 Site-wide Survival ............................................................................................................... 3-1
3.2 Year 1 Compliance with Performance Criteria ................................................................... 3-1
3.3 Summary and Future Actions ............................................................................................. 3-2
4.0 REFERENCES ................................................................................................................................... 4-3
APPENDIX A – SITE PHOTOGRAPHS
APPENDIX B – AS-BUILT SHEETS WITH MONITORING PLOT AND PHOTO POINT LOCATIONS
Exeltech Consulting, Inc.
Apron R Infrastructure Maintenance and Repair Project Renton, WA
NWS-2017-37 1-1 December 19, 2024
1.0 PROJECT OVERVIEW
The Boeing Company (Boeing) conducted the Apron R Infrastructure Maintenance and Repair Project
at the Renton, Washington plant located at the southernmost end of Lake Washington. The
approximate center point of the mitigation site is located at: 47.501559 N lat., -122.209542 W long.
The project was conducted to address in part the following issues that were identified at Apron R.
• Cracking and general deterioration of 6 -inch paving within the main airplane production tow
paths
• General apron settlement of 6 inches adjacent to pile -supported bulkheads and slabs creating
several areas of hard points and a less functional apron area
• High occurrence of slab faulting
• Ponding and areas of poor drainage
• Sheet flow of stormwater directly to Lake Washington
• Erosion under the west ramp
• Deterioration of west ramp timber superstructure connection elements
• Bulkhead undermining
• Steel sheet pile wall deterioration and failure
• Paving areas that have known or suspected voids under them
The work to repair the apron was conducted between November 2019 and September 2023. Work
was conducted per the applicable permit requirements. To offset the potential impacts to the
environment, Boeing prepared a Compensatory Mitigation Plan (Wood and W SP 2020) that included
overwater structure and piling removal and enhancement of shoreline vegetative communities.
Activities to offset potential impacts included:
• removing over-water cover,
• removal of 353 piles,
• habitat enhancement including:
o placement of large woody debris within the adjacent Department of Natural
Resources (DNR) mitigation site,
o tree replacement within the DNR mitigation site, and
o invasive vegetation removal and native species planting
The overwater structure and piling removal portion of the compensatory mitigation have been
described in the As-Built Report (WSP 2023) for Apron R. As special condition of the US Army Corps of
Engineers (Corps) Nationwide Permit 39 (NWP 39), a final as -built report for the habitat mitigation
was required to be submitted. The as-built report served as Year 0 of the 5-year monitoring
requirement.
Exeltech Consulting, Inc.
Apron R Infrastructure Maintenance and Repair Project Renton, WA
NWS-2017-37 1-2 December 19, 2024
This monitoring report documents the Year 1 site conditions following mitigation planting of riparian
habitat, as observed by Exeltech Consulting, Inc. (Exeltech).
1.1 USACE Reference Number
The agency reference number for this project is: NWS -2017-37.
1.2 Responsible Parties
• Permittee: The Boeing Company – Mark Clement
• Monitoring: Exeltech – Jon Chalfant
• Maintenance Contractor: BrightView
• Site Ownership: The Boeing Company
1.3 Summary of Site Activities
• Plant Installation: between November 2023 and July 2023
• As-Built Report: November 2023 (WSP 2023)
• Site Replanting: August -September 2024
• Seeding Application: May 2024
Per the As-Built Report (WSP 2023), a total of 220 trees and 5,700 shrubs and perennial groundcover
plants were originally installed on the site between November 2022 and July 2023. Plant survival was
evaluated in November 2023, and replacement planting in-kind occurred during the growing season in
2024.
Exeltech Consulting, Inc.
Apron R Infrastructure Maintenance and Repair Project Renton, WA
NWS-2017-37 2-3 December 19, 2024
2.0 MONITORING PROGRAM
Vegetation within revegetated areas will be monitored for a total of 5 years to assess the
performance of the restoration. During the monitoring period, plant survival and establishment will be
documented and compared to performance standards specified bel ow. Monitoring would begin by
providing as-built plans immediately following completion of the installation. Subsequent monitoring
will occur at the end of each growing season (late August – September) in years 1, 2, 3, and 5
following construction. A memo randum summarizing existing conditions at the time of each
monitoring event and compliance with specified performance standards for each monitoring year will
be submitted to the appropriate agency for review and approval within 90 days of each monitoring
event.
Prior to the first monitoring event, the location of four permanent sampling plots (two each bank) will
be selected in representative areas of the riparian buffer plantings zones. The size, location, and
shape of sample plots will be determined using the a s-built plans and will encompass approximately
100 square feet. The locations of the sampling plots will be recorded on the as -built plans. The center
of each sample plot will be marked with rebar and a tall white polyvinyl chloride (PVC) pipe during the
first monitoring event to enable relocation during subsequent monitoring events. During each
monitoring event at the identified locations, plant species observed within the site will be identified
and recorded to confirm percent survival. Overall developmen t of the planted communities will be
documented through photographs taken during 5 monitoring years. Photo points will be established
during year 1 monitoring and identified on the as -built plan. These photos points will be used for the
duration of the project.
Plant survival and growth will be assessed throughout the entirety of the restored area during the first
year of monitoring. During the first monitoring event, all individual plantings will be identified as living
or dead. Dead plants will be flagged in th e field for replacement, and their species noted. Site -wide
plant survival will be calculated by subtracting the total number of dead plantings observed during the
monitoring event from the total number of plants installed as listed in the as -built plans.
During the 5 -year monitoring period, non -native invasive species such as Scot's broom (Cytisus
scoparius), Himalayan and evergreen blackberry (Rubus laciniatus), reed canarygrass (Phalaris
arundinacea), purple loosestrife (Lythrum salicaria), English holly (Ilex aquifolium), Japanese
knotweed, giant knotweed (Polygonum sachalinense), and English ivy shall be removed and disposed
of off-site at an approved facility. In addition to the plants listed above, other non -native and invasive
plants will be managed and removed should they establish.
The native planting areas on Boeing property will be maintained for 5 years post -construction as
described in the Revised Compensatory Mitigation Plan (Wood and WSP 2020). Plantings on the DNR
mitigation site will be maintained by DNR and are not included in the monitoring p rogram.
Exeltech Consulting, Inc.
Apron R Infrastructure Maintenance and Repair Project Renton, WA
NWS-2017-37 2-4 December 19, 2024
2.1 Performance Standards
The performance standards established for the site are as follows:
• Year 1
o 100% survival of plants; and
o Not more than 10% coverage by non-native invasive species.
• Years 2, 3, and 5
o 100% survival for Year 2 for container plants and 80% for live stakes ;
o 80% plant survival for Year 3 and Year 5; and
o Not more than 10% coverage by non-native invasive species in any year.
Plant survival during the first year would be the responsibility of the landscape contractor and would
be ensured through correct installation procedures, ongoing maintenance, and replanting, if needed.
Growth during the first year was expected to be minimal as plants were becoming established.
Some plant mortality is expected during Years 2, 3, and 5. Planted vegetation is expected to perform
well. Plants will receive supplemental watering and routine maintenance to maintain plant vigor. With
proper growing conditions and maintenance, it is assumed that 80% of the plants will survive a nd be
present during monitoring Years 2, 3, and 5.
Exeltech Consulting, Inc.
Apron R Infrastructure Maintenance and Repair Project Renton, WA
NWS-2017-37 3-1 December 19, 2024
3.0 YEAR 1 MONITORING RESULTS
The Year 1 monitoring was conducted on August 29, 2024. As prescribed in the Revised Compensatory
Mitigation Plan (Wood and WSP 2020), plant survival and growth were assessed throughout the
entirety of the restored area during the first year of monitoring. In addition, four permanent plots
were established to evaluate the site’s performance for the five -year monitoring period.
3.1 Site -wide Survival
During the monitoring event, all individual plantings were identified as living or dead and their species
noted. Plants were previously flagged and color coded by species during the November 2023 As-Built
survey. Site-wide plant survival was calculated by subtracting the total number of dead plantings
observed during the monitoring event from the total number of plants installed as listed in the as -
built plans.
Area Plant Year 1
Monitoring
Plants Total
Planting
Design Plants
Total
Difference
Year 1 and
Design
Percent
Survival
Area A Hooker willow 11 220 -209 5%
Area A Red-twig dogwood 0 100 -100 0%
Area B/C/D Snowberry 421 450 -29 94%
Area D Nootka Rose 206 250 -44 82%
Area D Thimbleberry 214 250 -36 86%
Area D Tall Oregon grape 214 250 -36 86%
Area B/C/D Kinnikinnick 4,130 4,400 -270 94%
3.2 Year 1 Compliance with Performance Criteria
Four sample plots were established for yearly monitoring following the method described in the
Revised Compensatory Mitigation Plan (Wood and WSP 2020). All plots are approximately 10ft by 10ft
in size and are located adjacent to the fenceline. Plant species were identified and survival was noted
for all plots. Within each plot percent coverage by non -native invasive species was recorded. Photo
points were established within the planting area. The following table provides the Year 1 monitoring
results for the four plots.
Performance Criterion Year 1 Monitoring Result (All
Plots)
Year 1 Performance Criterion
Met?
100% Survival of plants 21 dead plants No
Not more than 10% coverage by
non-native invasive species
1.2% average cover Yes
Exeltech Consulting, Inc.
Apron R Infrastructure Maintenance and Repair Project Renton, WA
NWS-2017-37 3-2 December 19, 2024
3.3 Summary and Future Actions
Overall, the site is performing well. Invasive species cover is low and planted shrub/groundcover
species are surviving well, although not meeting the 100% survival performance standard. Planted
trees (willow and dogwood) experienced very low survival. Throughout the entire site herbivory and
at times severe grazing have impacted the plantings. Irrigation has also been an issue at the site and
may have contributed to failure of some of these plants to thrive; maintenance of the irrigation
system is ongoing. Site replanting to replace missing or dead plants occurred in late August through
September to increase the number of installed plants to meet the original planting plan. Fencing was
added at some locations to reduce herbivory impacts. Additional monitoring of the site will be
performed and identified issues will be addressed by the maintenance team.
Exeltech Consulting, Inc.
Apron R Infrastructure Maintenance and Repair Project Renton, WA
NWS-2017-37 4-3 December 19, 2024
4.0 REFERENCES
Wood Environment & Infrastructure Solutions, Inc. and WSP. 2020. Revised Compensatory Mitigation
Plan, Apron R Infrastructure Maintenance and Repair Project (NWS-2017-37), The Boeing
Company, Renton, Washington (Lake Washington). Prepared for The Boeing Company.
WSP USA, Inc. 2023. As-Built Report, Apron R Infrastructure Maintenance and Repair Project (NWS -
2017-37), The Boeing Company, Renton, Washington (Lake Washington). Prepared for The
Boeing Company.
APPENDIX A
Site Photographs
Site Photographs
Photo Point 1. Western terminus of planting
area, fa cing east viewing row of planted
kinnikinnick.
Photo Point 2. Western segment of planting
area, fa cing west along shoreline; Renton
Rowing Center building shown on the right side
of photo.
Site Photographs
Photo Point 3. From center of Plot 1, view facing east.
Photo Point 4. From center of Plot 2, view facing west.
Site Photographs
Photo Point 5. From center of Plot 2, view facing east.
Photo Point 6. Eastern portion of the planting area, view facing northeast.
Site Photographs
Photo Point 7. Eastern portion of the planting area, view facing southwest.
Photo Point 8. Eastern terminus of the planting area, photo taken from Plot 4, view facing
southwest.
APPENDIX B
As-Built Sheets with
Monitoring Plots and Photo Points Identified
PHOTO POINT 1
PHOTO POINT 2
PHOTO POINT 3
PHOTO POINTS 4 & 5
PHOTO POINT AND DIRECTION
OF PHOTO
PHOTO POINTS 6 & 7
PHOTO POINT 8
PHOTO POINT AND DIRECTION
OF PHOTO