HomeMy WebLinkAboutCM_Construction_Mitigation_Description_190315_v1.pdf
177 Western Avenue West, Suite 266, Seattle, WA 98119 | p: 206.331.3795 | e: info@thirdplacedesigncoop.com
third place design
co-operative
where architecture meets community
Homestead Willowcrest Townhomes
Construction Mitigation Description Please provide a written narrative addressing each of the
following:
• Proposed construction dates (begin and end dates):
Construction is scheduled to begin in late summer/early fall of 2019 and will last approximately
14 months.
• Hours and days of operation:
Construction activities will be restricted to the hours between 7:00am and 8:00pm, Monday
through Friday. If construction activities take place on a Saturday, they will be restricted to the
hours between 9am and 8pm.
• Proposed hauling/transportation routes:
The construction entrance to the site will be from Glennwood Ave, through the shared access
drive. Haul hours will be scheduled between 8:30am and 3:30pm, Monday through Friday. A
construction plan identifying specific haul routes and hours will be submitted for approval.
• Measures to be implemented to minimize dust, traffic and transportation impacts,
erosion, mud, noise, and other noxious characteristics:
Erosion control BMP’s will be employed on site per Appendix D in the City of Renton
Amendments to the King County Surface Water Design Manual. All sedimentation/erosion
facilities will be in operation prior to clearing and building construction and maintained until
construction is completed. BMP’s are outlined in the Technical Information Report (TIR)
provided for this application, and include the following proposed measures:
• Clearing limits will be delineated by perimeter silt fencing and chain link fencing
• Temporary cover will be installed if an area is to remain unworked for more than 7 days in
the dry season or more than 2 working days in the wet season. Any area to remain
unworked for more than 30 days shall be seeded and sodded.
• Perimeter protection will be implemented by silt fencing around the site perimeter as
required by drainage paths
• A stabilized construction entrance will be built for construction traffic
• Catch basin protection will be provided
• Surface water will be controlled and conveyed via swales with check dams if necessary
• Dust control, if required, will be provided through the limited use of water trucks.
• Subgrade areas will be proof rolled to locate any soft or pumping soils. If soft or pumping
soils are observed, they should be removed and replaced with compacted structural fill.
• If deep pockets of soft or pumping soils are encountered outside the building areas, they
should be supported with non-woven geotextile fabric prior to placing structural fill.
• For earthwork that occurs in wet weather, the ground surface should be sloped so that
surface water is directed away from the work area and ponded water does not develop.
177 Western Avenue West, Suite 266, Seattle, WA 98119 | p: 206.331.3795 | e: info@thirdplacedesigncoop.com
third place design
co-operative
where architecture meets community
• Earthwork activities should not take place during periods of moderate to heavy
precipitation
• Slopes with exposed soils should be covered with plastic sheeting.
• Site soils to be used as fill should not be left uncompacted and exposed to moisture. Soil
stockpiles that will be used as structural fill should be covered with plastic sheeting.
• Permanent cut or fill slopes should be constructed at inclinations of 2H:1V or flatter, 3H:1V
where possible for landscape purposes.
Transportation impacts related to construction activities will be mitigated as needed according
to the city’s requirements. The construction entrance will be on Glennwood Ave NE.
The contractor will prepare air quality control plans in accordance with the dust and odor
control BMP’s required by the City. All City-required precautions to safeguard against
environmental health hazards will be incorporated into construction plans and contractor
specifications, including contingency planning to safely identify, segregate, and dispose of
hazardous waste, best practices to avoid hazardous spills, and a spill prevention, control, and
countermeasure plan.
All City-required noise mitigation measures will be incorporated into construction plans and
contractor specifications, including location and barrier guidelines for stationary equipment,
best practices for equipment operation and maintenance, and noise mitigation training for
construction crews.
• Any special hours proposed for construction or hauling:
No special hours are proposed at this time.
• Preliminary traffic control plan:
The contractor will provide a traffic control plan for review and approval.