Applicants of construction projects disturbing 1 or more acres of soil are required to file for coverage under the State Water Resources Control Board (SWRCB), Order No. 99–08–DWQ, National Pollutant Discharge Elimination System (NPDES) General Permit No. CAS000002 for Discharges of Storm Water Runoff Associated with Construction Activity (General Permit). Construction activities include clearing, grading, excavation, stockpiling, and reconstruction of existing facilities involving removal and replacement.
Project owners are required to submit a complete Notice of Intent (NOI) package to the SWRCB. A complete NOI package consists of an NOI form, site map and fee. The General Permit also requires the development and implementation of a Storm Water Pollution Prevention Plan (SWPPP). The SWPPP should contain a site map which shows the construction site perimeter, existing and proposed buildings, lots, roadways, storm water collection and discharge points, general topography both before and after construction, and drainage patterns across the project. The SWPPP must list Best Management Practices (BMPs) the discharger will use to protect storm water runoff and the placement of those BMPs.
Agricultural construction related to reservoirs, access avenues and structures are still subject to the General Permit requirement.
The SWRCB website has more information regarding the General Permit and associated requirements.
Even if a construction project is exempt from the General Permit, it is not exempt from discharging polluted runoff under Sonoma County Code Chapter 11.