1605 SE EVERETT MALL WAY WALMART 2018-01-01 MF Import

, n = A , wSeattleww.pacland.comWashigton ��JT206.522.9510 TURNING VISIONS INTO REALITY G. Operation and Maintenance Plan The owner of the project site shall be responsible for maintaining the existing and proposed stormwater facilities in accordance with local requirements, manufacturer guidelines where appropriate, and this Operation and Maintenance Plan (O&M Plan). J Proper maintenance is important for adequate functioning of the stormwater facilities. City of Everett Maintenance Checklists for the following stormwater facilities/structures are provided in Appendix E: Closed Detention Systems (TanksNauIts) Existing onsite oversized conveyance pipes between catch basins in the main parking field provide storage during larger storm events. As stormwater is detained via the downstream flow control structure, it backs up into these pipes to be released at a previously designed flow rate. Control Structure/Flow Restrictor The modified type II catch basin near the main signalized entrance contains a vertical riser pipe with a —4" orifice through the welded plate at the bottom of the riser. This restriction releases stormwater at a previously designed flow rate. Catch Basins The type I and type II concrete catch basins located throughout the site collect stormwater and convey it to the flow control structure. StormfilterTM Units r These proprietary filtration cartridges are located in structures in the main parking field as defined on the Grading and Drainage Plan. These facilities collect stormwater from the parking lot and filter the design treatment storm to provide basic stormwater treatment. The units require maintenance and replacement cartridges on a scheduled basis. Fencing/Shrubbery Screen/Other Landscaping Existing landscaping is located within the parking field and at the edge of the property. These areas should be maintained to prevent damage to the stormwater system resulting from sediment runoff and/or the collection of debris. Pervious Pavement The new-raised pedestrian sidewalk to Everett Mall Way and the revised site entrance contain pervious pavement either in the form of pervious asphalt or pervious pavers. These areas function to reduce surface runoff and promote on-site infiltration. Owner Requirements The owner is responsible for maintaining the site stormwater facilities in a manner consistent with this O&M Plan. Additionally, the owner must keep a copy of the O&M Plan within the 1605 Everett Mall Way building for review by the City of Everett upon request. The O&M Plan should be updated with completed checklists and a maintenance activity log throughout the life of the project. Everett Mall Plaza Parcel Ill Retail Expansion Stormwater Site Plan Page 25