HomeMy WebLinkAboutCM_Mitigation_Description_180315SAZEI Design Group, LLC
6608 110th Ave. N. E. Te l: (425) 214-2280
Kirkland, WA. 98033
Avon Development, Inc.
1011 North 37th Street
Renton, Washington 98056
CONSTRUCTION MITIGATION
NARRATIVE
Prepared For:
Avon Development
2-Lot Short Plat
1909 NE 14th Street
Renton, Washington
Prepared BY:
SAZEI Design Group, LLC
6608 110th Ave NE, Kirkland, WA 98033
January 16, 2018
Project proposes construction of a 2-lot short plat. The site is located
1909 NE 14th Street, Renton WA. The following construction
mitigation measures will be implemented during construction and site
development:
1- Proposed construction date for site development is set for April 23, 2018
and an anticipated completion date of June 15, 2108
2- Construction related days and hours will be:
7 am to 6 pm on weekdays
9 am to 6 pm on Saturdays.
There will be no work on Sundays or legal holidays.
3- Construction hauling and transportation route will be from NE 14th street
to Jones Ave NE through Kennewick Place NE that connect to interstate
I-5
4- Any excavated material removed from the construction site and deposited on
property within the City limits must be done in compliance with a valid clearing
& grading permit. Locations for the mobilization area and stockpiled material
must be approved by the Clearing and Grading Inspector at least 24 hours in
advance of any stockpiling.
5- To reduce the potential for erosion of exposed soils, or when rainy seaso n
construction is permitted, the following Best Management Practices (BMPs)
are required.
Preserve natural vegetation for as long as possible or as required by the
Clearing and Grading Inspector.
Protect exposed soil using plastic (EC-14), erosion control blankets, straw or
mulch (City of Renton Guide to Mulch Materials, Rates, and Use Chart), or
as directed by the Clearing and Grading Inspector.
Install catch basin inserts as required by the Clearing and Grading Inspector or
permit conditions of approval.
Install a temporary sediment pond, a series of sedimentation tanks, temporary
filter vaults, or other sediment control facilities. Installation of exposed
aggregate surfaces requires a separate effluent collection pond onsite.
6- The contractor must maintain a sweeper on site during earthwork and
immediately remove soil that has been tracked onto paved areas as result
of construction.
7- THE 12 ELEMENTS OF A CONSTRUCTION CSWPPP SHALL BE
IMPLEMENTED AS FOLLOWS:
1. Preserve Vegetation/Mark Clearing Limits: The clearing limits are
indicated on the plan sheet. Furthermore, clearing and grading will be
limited to only areas that need to be disturbed for grading/construction
of the road surface to preserve as much natural vegetation as possible.
Field marking the clearing limits shall be completed prior to clearing
and grubbing activities.
BMP's: Preserve Natural Vegetation (VEG)
Field Marking Clearing Limits (CL)
2. Establish Construction Access: Access to the construction site shall be
limited to the rock construction entrance. The construction entrance shall
be extended to provide access to the construction vehicle/equipment
staging and employee parking areas.
BMP's: Stabilized Construction Entrance (CE)
3. Control of Flow Rates: Storm water detention: No detention is
proposed for the site since the increase in volume is minimal
4. Installation of Perimeter Sediment Controls: Sediment control will be
provided through a combination of filtration through the surround on-site
vegetation, filter fence, straw bails,
BMP's: Silt Fence (FF)
5. Soils Stabilization: Temporary and permanent soil stabilization will be
provided. Temporary stabilization will be provided through the
application of straw and/or plastic sheeting to exposed, worked earth.
From October 1 until April 30, no exposed soil may remain exposed and
unworked for more than two days; after May 1, no exposed soil may
remain exposed and unworked for more than seven days.
6. Slope Protection: Slopes shall be protected from erosion through cover
and prevention of concentrated surface runoff flows.
BMP's: Plastic Sheeting,
7. Protection of Permanent Drain Inlets and Dust/Mud Control: Inlet
protection will be provided for all catch basins.
BMP’s: Inlet Protection
BMP’s: Street Sweeping and watering of dust areas
8. Stabilization of Channels and Outlets: All channel slopes shall be
constructed and protected against erosion in accordance with City of
Renton
BMP's: None required
9. Pollutant Control: Pollutants shall be controlled as described in the
Potential Pollutants section of this SWPPP.
10. Dewatering Control: De-watering: Interception of the water table is
not expected to occur, even if there is an increase in precipitation.
However, should ground water flows be encountered, the flows can be
directed to on site native vegetation for cleanup.
BMP's: Native vegetation (As Required)
11. BMP Maintenance: All BMP's and SWPPP elements shall be
inspected daily and maintained as required.
12. Project Management: The project shall be managed in a cooperative
effort by the project manager, contractor, engineer, and the city of Renton
inspector. During the construction process, if unforeseen issues arise that
cannot be resolved on site, construction activity (other than SWPPP
maintenance) shall be halted and the county inspector and the project
engineer are to be contacted and informed of the situation. The Erosion
Control Lead TBD