10705 HOLLY DR 2018-02-01 - Laserfiche WebLink

. , . . _. � Technical Memorandum—Habitat Assessment for Holly Drive Lift Station Upgrade December 23, 2015 Human disturbance associated with the lift station improvements will increase for approximately 4 months during the summer of 2016 and will return to current levels once construction is complete. The potential for release of contaminants during construction will be low, as all significant ground-disturbing work will be limited to the area within the fence line and BMPs for the control of sedimentation (e.g., silt fences, straw bales, and sedimentation ponds) will be utilized during construction as needed to prevent release of contaminated and turbid water into Swamp Creek. Also, construction methods will be modified to minimize impacts to the environment, including caisson installation of the new wet well instead of open trenching. Critical Habitat PCEs The U.S. Fish& Wildlife Service IPaC Database indicated that there is no critical habitat in the project area for any species under their jurisdiction. Further, the project area is not located in any of the designated critical habitat subbasins for Puget Sound Chinook salmon. It is unlikely that the upper reaches of Swamp Creek in the project area are considered critical habitat for Chinook salmon and steelhead that are present below Lake Stickney more than 2 miles downstream. Responses to PCEs potentially pertinent to the proposed lift station improvements are presented below: • Pu�et Sound Chinook Salmon PCE 1: Freshwater spawning sites with water quantity and quality conditions and substrate supporting spawning, incubation, and larval development. Not applicable to the Holly Drive Lift Station project area, as there is no known salmonid spawning in Swamp Creek above Lake Stickney. • Puget Sound Chinook Salmon PCE 2: Freshwater rearing sites with water quantity and floodplain connectivity to form and maintain physical habitat conditions and support juvenile growth and mobility; water quality and forage supporting juvenile development; and natural cover such as shade, submerged and overhanging large wood, log jams, and beaver dams, aquatic vegetation, large rocks and boulders, side channels, and undercut banks. According to the Salmonscape Database maps, no freshwater rearing sites for juvenile Chinook salmon are present in Swamp Creek upstream of Lake Stickney, which is approximately 2 miles downstream of the project area. The proposed project will not significantly impact water quality in /� ��