2600 FEDERAL AVE 2021 PORT OF EVERETT 2025-09-29

influent and effluent concentrations and aggregate pollutant load reduction are 78 mg/L, 26 mg/L, and 67%, respectively. • For the 8 qualifying events with peak discharge exceeding design flow (ranging from 120 to 257% of the design rate), results ranged from 52%to 96% TSS removal, with an average of 72%. • Due to the characteristics of the hydrographs, the field results generally reflect flows below (ranging between 20 and 60 percent of) the tested facilities' design rate. During these sub-design flow rate periods, some of the cartridges operate at or near their individual full design flow rate (generally between 4 and 7.5 GPM for an 18" cartridge effective height)because their float valves have opened. Float valves remain closed on the remaining cartridges, which operate at their base "trickle"rate of 1 to 1.5 GPM. • Laboratory testing using U.S. Silica's Sil-Co-Sil 106 fine silica product showed an average 87% TSS removal for testing at 7.5 GPM per cartridge (100% design flow rate). • Other relevant testing at I-5 Lake Union, Greenville Yards (New Jersey), and Ski Run Marina(Lake Tahoe) facilities shows consistent TSS removals in the 75 to 85% range. Note that the evaluators operated the I-5 Lake Union at 50%, 100%, and 125%of design flow. • SMI's application included a satisfactory"Factors other than treatment performance" discussion. Note:Ecology's 80% TSS removal goal applies to 100 mg/1 and greater influent TSS. Below 100 mg/L influent TSS, the goal is 20 mg/L effluent TSS. Technology Description: The Stormwater Management StormFiltero (StormFilter), a flow-through stormwater filtration system, improves the quality of stormwater runoff from the urban environment by removing pollutants. The StormFilter can treat runoff from a wide variety of sites including, but not limited to: retail and commercial development, residential streets, urban roadways, freeways, and industrial sites such as shipyards, foundries, etc. Operation: The StormFilter is typically comprised of a vault that houses rechargeable, media-filled, filter cartridges. Various media may be used,but this designation covers only the zeolite- perlite-granulated activated carbon (ZPGTM)medium. Stormwater from storm drains percolates through these media-filled cartridges, which trap particulates and may remove pollutants such as dissolved metals, nutrients, and hydrocarbons. During the filtering process, the StormFilter system also removes surface scum and floating oil and grease. Once filtered through the media, the treated stormwater is directed to a collection pipe or discharged to an open channel drainage way. This document includes a bypass schematic for flow rates exceeding the water quality design flow rate on page 8. CONTECH-StormFilter®GULD Maintenance Update(November 2012) Page 17