7000 HARDESON RD 2018-01-02 MF Import

Adminio!. ative Ofticas 11'3 1641h St. SW Suite 200 Lynnwood, WA 98037-8121 (206) 348-7100 January 2,1997 Fax 348-2319 Executive Director Mr. Larry Crawford Joyce F. Olson Director of Engineering and Public Services City of Everett 3200 Cedar St Everett, WA 98201 I C8 _ J997 `lw"#"D# CI Or E.............. Public Works Dep . Community Transit RE: Compost Stormwater Filter System/Community Transit North Base Facility Dear Larry; This letter represents agreement between the City of Everett and Community Transit regarding maintenance, monitoring and contingency plans required by the Determination of Non -Significance (DNS) for SEPA #13-96 dated Apirl 11, 1996 for the Community Transit/North Base Facility Compost Stormwater Filter (CSF) System. To meet the conditions for a monitoring plan, as specified in the DNS, Community Transit or their representative will install and operate equipment which will continuously monitor the level of water in the compost filter for a period of at least two years. A copy of the level record will be provided to the City of Everett monthly. After the two year period, the continuous level monitoring equipment may be replaced by a crest gage with weekly readings provided to the City quarterly. The first year of operation will be considered a trial year. During the first year of operation, Community Transit or their representative will use the results of the water level monitoring to develop a maintenance schedule tailored to this particular compost filter installation. Maintenance activities will be planned and scheduled in response to decreases in hydraulic capacity detected by the water level monitoring so that valve adjustments, filter backflushing, and/or radial cartridge replacement occur prior to the flew rate through the filter decreasing below the design flow rate, as evidenced by the level of water in the filter reaching the filter's overflow level. The trial period may be extended one year at the City's discretion if abnormal rainfall, monitoring equipment failure or other circumstances prevent sufficient collection of data. Maintenance for the CSF system will be performed in accordance with the Compost Filter Stormwater Filter Type 11 Best Management Practices Document submitted to the City of Everett on July 9, 1996, or subsequently updates documents or procedures approved by the City of Everett. Snohomish County Public Transportation Benefit Area Corporation -