1606 SE EVERETT MALL WAY ANTHEM SELF STORAGE 2025-07-25

I C=:: NTECH0.ENGINEERED SOLUTIONS Size and Cost Estimate I Prepared by John Megrditchian on May 1,2014 IAnthem Self Storage — Stormwater Treatment System Everett, WA I Information provided: • Structure ID = North South • Total Area (acre) = 0.39 0.34 I • Percent Impervious = 100 100 • Water Quality Flow, WQF (cfs) = 0.0618 0.0539 • Peak Flow, Q100 (cfs) = 0.4235 0.3692 IAssumptions: • Media = ZPG cartridges I • Cartridge Height = 18" • Per Cartridge flow rate = 7.5 gpm • Drop required from RIM to outlet = 2.3' minimum I • Presiding agency = City of Everett Size and cost estimates: I The StormFilter is a flow-based system, and is therefore sized by calculating the peak water quality flow rate associated with the design storm. The water quality flow rate was calculated by the consulting engineer using WWHM and was provided to Contech Engineered Solutions LLC for the purposes of developing this estimate. IStructure Water Approximate No. of Estimated ID Quality Depth Cartridges System Size Cost Flow I North 0.0618 4' 4 Deep $15,575 Catchbasin eep South 0.0539 4' 4 Catchbasin $15,575 I I Typically the precast StormFilters have internal bypass capacities of 1.0 cfs. If the peak discharge off the site is expected to exceed this rate, we recommend placing a high-flow bypass upstream of the StormFilter system. Contech Engineered Solutions could provide our high-flow bypass, the StormGate, which provides a combination weir-orifice control structure to limit the flow to the StormFilter. The estimated cost of this structure is $4,000. The 1 final cost would depend on the actual depth and size of the unit. I I ©2012 Contech Engineered Solutions LLC 11835 NE Glenn Widing Dr.,Portland OR 97220 Page 1 of 1 www.conteches.com Toll-free:800.548.4667 Fax:800.561.1271 TS-P027