9212 HOLLY DR 2018-01-02 MF Import

F I 3. Ecology finds that the Vortechs, sized at an operating rate of 35 GPM/sf, could also provide: o Water quality benefits in retrof ituations. o The first component in a treatment train. o Effective removal of deicing grit/sand. o Applicable for low head situations and/or utility conflicts where it is found to he in�casible or impractical to use any other approved practice. Ecology's Conditions of Use: I. Vortechs Systems must be design(d, assembled, installed, operated, and maintained in accordance with applicable CVN TECH Product Design Manual Version 4.1 (April 2006) or most current versions, avid the Ecology Decision. 2. Discharges from the Vortechs System shall not cause or contribute to wa( quality standards violations in receiving waters. Applicant: CONTECH Stormwater Solutions Inc., Manufacturer and Vendor Applicant's Address: 12021 B NE Airport Way Portland, OR 97220 Application Documents: • Vortechs System Conditional Use Approval Application Letter to the Washington State Department of Ecology (June 25, 2003) ' • Vortechs Stormwater Treatment System Technology Report, June 2003 Technical Appendices I through 16 ' applicant's Use Level Request: Conditional Use Designation as a Basic Treatment device in accordance with Ecology's 2001 ' stormwater manual. Applicant's Performance Claims: Based on laboratory trials, the Vortechs System will achieve an 80% TSS removal efficiency for sediment particles ranging from 38 to 75 microns at an operating rate of 13 gallons per minute tper square foot (GPM/sf) at the peak Flow for the Ecology design treatment storm. The system is recommended only for sites likely to produce relatively high TSS concentrations (above 100 mg/L), where TSS is primarily composed of 50 microns and larger. Potentially appropriate sites include parking lots, highways and urban streets, material transfer sites, hydroca:bon transfer sites, retrofits, steep/erosive sites, and space -limited sites. ' Z a4