City of Seattle

Ed Murray, Mayor


SUBJECT:   Storm Drain Insert Reminder
10/19/2012  9:00:00 AM
Bryan Stevens  (206) 684-5045

Storm Drain Insert Reminder
Builders Need to Inspect and Maintain Storm Drain “Socks”

SEATTLE – With onset of the rainy season, the City of Seattle’s Department of Planning and Development (DPD) is reminding builders working in Seattle to inspect and maintain any temporary storm drain inserts they have installed as part of construction projects. 

The inserts, also known as storm drain socks, are used on many construction projects to catch sediment not captured upstream by other construction-related erosion control devices.  Regulations for the use of the socks include the following:

  • Inspections should be made on a regular basis, especially after large storm events. Inlet protection devices shall be cleaned or removed and replaced when sediment has filled one-third of the available storage (unless a different standard is specified by the product manufacturer).
  • Do not wash sediment into storm drains while cleaning. Spread all excavated material evenly over the surrounding land area or stockpile and stabilize as appropriate.
  • This Best Management Practice (BMP) shall be removed within 5 business days after final site stabilization is achieved, or after it is no longer needed, whichever is longer (BMP E3.65*).If inserts are removed during times of flooding, the builder is responsible for re-installing them per regulations.

To prevent flooding, the public is urged to clear clogged drains where it is safe and practical to do so.  Flooding should be reported to Seattle Public Utilities at 386-1800.

Rules for the use of the socks are available at DPD’s website at:  See Form #8.

* See Director’s Rule DPD 16-2009, 2009-004 SPU: Construction Stormwater Control Technical Requirements Manual