DPD would like to remind builders working in Seattle that they are responsible for complying with the regulations for temporary storm drain inserts, also known as “socks.” The inserts are used on many construction projects to catch sediment not captured upstream by other construction-related erosion control devices and can be an important temporary environmental safeguard.

Among the regulations:

• Builders must clean and/or replace the inserts when half of the trap is filled with sediments.
• Builders must inspect and maintain the inserts whenever ½ inch of rain falls within a 24-hour period.
• The inserts are to be removed by the builders within 30 days of site stabilization or after the temporary erosion measures are no longer needed.

If inserts are removed during times of flooding, the builder is responsible for re-installing them per regulations.

Regulations for the inserts are established by the City of Seattle’s Stormwater, Grading and Drainage Control Code (SMC 22.800) and DPD Director’s Rule 16-2000, “Construction Stormwater Control Technical Requirements Manual.”

A construction stormwater control plan is required for all projects that will require ground disturbance, including grading and footing excavation, in order to prevent erosion or transport of sediment or other pollutants from the construction site. The Temporary Erosion and Sediment Control (TESC) Standard Plan is available in both CAD and PDF on DPD’s Forms website (see #31).