Erosion control is a water quality and slope stability issue that has become increasingly important for all construction activities in Seattle. While erosion control measures have been required for most projects in Seattle that involve ground disturbance since January 31, 2000, an erosion control inspection is now required when the first ground disturbance occurs.

This applies to sites that involve:

• excavation in an Environmentally Critical Area (ECA)
• machine-excavation in areas other than ECA
• demolition which includes ground disturbance

The reason for this proactive approach to erosion control is that by the time DPD inspectors conduct a foundation inspection it may be too late for effective erosion control measures to be inspected, as grading and vegetation removal may have already caused erosion activity.

Contractors may benefit from this earlier erosion control inspection because it allows site conditions to be considered and erosion control tailored to the specific site. For example, rather than the entire perimeter of the site requiring a silt-fence, only one or two sides may be needed.

Exceptions
First ground disturbance inspections are not required for:

• up to one cubic yard of hand-digging, e.g., for deck post holes
• many flat lots or small additions
• sites that have pre-construction meetings where site inspectors are already involved.

If you have questions about whether you qualify for an exception, please call DPD's Site Development Team at (206) 684-8860.

Erosion Control Plan Now Required for Small Projects;
Helpful Prescriptive Plansheet Available
As of January 1, 2003, permit applicants with small construction projects must submit a plan showing the erosion control measures they will be using (see related news story). To assist in meeting this requirement, DPD offers a new prescriptive plansheet (24" X 36"), which provides a quick way for the builder to document erosion control methods and a clear field guide for both builder and inspector. The plansheet--which is available in the box at right--contains illustrations of common construction erosion control methods for the builder to select from and can be easily incorporated with building plans.

Background
Erosion control is a water quality and slope stability issue that has become increasingly important for all construction activities in Seattle. Preapplication site visits were implemented in early 2000 to ensure that site features requiring mitigation are identified prior to construction. This effort was undertaken in response to an increase in regulatory expectations, such as the listing of the Puget Sound Chinook salmon under the Endangered Species Act, and Seattle’s requirement to renew its National Pollution Discharge Elimination System permit.

Erosion control requirements state that:

• Silt fences and/or other erosion control measures must be in place prior to beginning clearing or any ground disturbance; and
• ECA buffers must be delineated, catch basins must be protected, and site access points must be shielded from soil tracking.

Fees
Erosion control inspection fees are generally included in permit application fees that you have already paid. Additional fees may apply when multiple inspections occur on difficult sites and you have used up the allotted inspection hours included in your permit fees.