HomeMy WebLinkAboutC_WetSeasonLetter_171215.pdfDecember 15, 2017
Dear :
SUBJECT:
The allowed time that a disturbed area can remain unworked without cover measures is reduced to two (2)
days, rather than seven (7).
Stockpiles, steep cut, and fill slopes are to be covered or protected with mulch, sod, plastic covering, jute mat
etc. if left unworked for more than 12 hours.
Cover materials (plastic, matting, etc.) sufficient to cover all disturbed areas, shall be stockpiled and available on
site.
All areas that are to be unworked during the wet season shall be seeded within one week of the beginning of the
west season. Seeding should be completed by September 23.
Mulch is required to protect all seeded areas.
Fifty linear feet of silt fence (and the necessary stakes) per disturbed acre must be stockpiled on site.
Properly installed silt fencing is mandatory along the downslope of all disturbed areas of the site. Perimeter
protection filters runoff and reduces the amount of sediment that may leave the site .
Denis Law Mayor
Community & Economic Development C.E. "Chip" Vincent, Administrator
Finley Short Plat
2525 Aberdeen Ave NE
Renton, WA 98056-2215
U16005573
NOTICE OF SPECIAL EROSION CONTROL REQUIREMENTS AND COLD WEATHER PAVING
It is that time of year to give notice to all developments within the City that any site with exposed soils during the
WET SEASON (October 1 to April 30) shall be subject to special erosion control provisions. These special
provisions are required in addition to the standard TESC cover measures. Please notify your staff of these
requirements, as well as respond in writing to this letter identifying the name and contact information for
your current project Certified Erosion and Sediment Control Lead (CESCL) or Erosion and Sediment
Control Supervisor if project is less than one acre.
All projects that clear, grade, or otherwise disturb the site, must provide erosion and sediment controls to the
maximum extent possible, to prevent the transport of sediment from the project site to downstream drainage
facilities, water resources, and adjacent properties.
The following provisions for wet season construction are detailed in Appendix D of the 2016 City of Renton Surface
Water Design Manual. Please ensure your site is protected and complies with the special provisions outlined below.
The basic requirements are:
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1055 South Grady Way, Renton, WA 98057 rentonwa.gov
Thank you for your cooperation. If you have any questions, please contact your project inspector or you may reach me at
425-430-7299 or bbannwarth@rentonwa.gov
Sincerely,
Brianne Bannwarth
Development Engineering Manager
Sediment retention is required unless no offsite discharge is anticipated for the specific design flow.
Construction road and parking lot stabilization are required for all sites unless the site is underlain by coarse-grained
soil.
Surface water controls are required unless no offsite discharge is anticipated for the specific design flow.
Phasing and more conservative BMP's must be evaluated for construction activity near surface waters.
Any runoff generated by dewatering shall be treated through construction of a sediment trap when there is sufficient
space or by releasing the water to a well vegetated, gently sloping area. Since pumps are used for dewatering, it may be
possible to pump the sediment-laden water well away from the surface water so that vegetation can be more effectively
utilized for treatment. A straw bale filter shall be placed around the discharge from the dewatering pump. If there is not
space for a sediment trap or 25 feet of suitable vegetation, other filtration methods shall be required.
The frequency of maintenance review should be increased from weekly to daily where warranted.
Pat Miller, Construction Inspection Supervisor
Jenny Cisneros, Administrative Secretary
Page 2 of 2
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In addition, any paving performed during COLD WEATHER (October 1 - March 31) shall be subject to special provisions.
The basic requirements are:
1.The contractor shall submit a written request to the engineer (City project manager) requesting to pave wearing course if
paving between October 1st through March 31st.
WSDOT specification 5-04.3(16) Weather Limitations describes the temperature limitation for cold weather paving.
The contractor should have a material tester onsite to verify both compaction as well as temperature.
Reports should be sent to the City of Renton ensuring that the compaction and temperature were met during paving.
The City of Renton is committed to effective erosion and sediment control practices. Please be advised if voluntary
action is not taken to properly protect your site, a civil infraction citation can be issued and civil penalties will be
assessed for each and every day the infraction continues. Fines under Renton Municipal Code Title I, Chapter 3, are as
follows: First three (3) days of violation at $100 a day; second three (3) days of violation at $200 a day; third (3) days of
violation at $300 a day and $500 a day each additional day thereafter.
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Ann Fowler, Development Engineer Project Manager