Stormwater Discharge System Source Control Evaluation

The NPDES and the state of Oregon 1200-Z Industrial Stormwater General Permit require monitoring of stormwater discharges from the site. Stormwater is captured in multiple catch basins and discharged via two conveyance systems to regulated outfalls to the Willamette River. Due to past exceedances of total suspended solids benchmark standards established in the NPDES and 1200-Z Permits and results from an evaluation of the older stormwater system’s condition, the older stormwater system was temporarily closed in 2009 to eliminate stormwater discharge from a significant portion of the Site. Farallon is visually monitoring the area during the temporary closure to identify areas that may be affected by the closure of the stormwater conveyance system. No adverse effects from the closure have been identified. Farallon currently is awaiting approval for permanent closure of the stormwater system.