3500 TERMINAL AVE 2022-08-25 - Laserfiche WebLink

r 1 // Pact of 44 EVERETT MITIGATED DETERMINATION OF NON-SIGNIFICANCE (MDNS) PORT OF EVERETT South Terminal Modernization,Phase 2 SEPA File No. 2016-12 DESCRIPTION OF PROPOSAL: The purpose of the project is to modernize existing infrastructure to meet 21s` Century cargo handling needs at the Port's South Terminal. This entails strengthening the existing South Terminal Wharf in order to support ongoing and anticipated terminal operations including the addition of two 100-foot gauge rail-mounted gantry cranes. The wharf's load capacity is currently rated at 500 pounds per square foot (psf). The project will increase the load capacity to 1,000 psf. This improved capacity and the addition of two 100-foot gauge cranes will allow the Port to continue to serve its existing customers and meet the changing needs of the local aerospace industry. The project is comprised of four primary elements: 1. Demolition:The existing Building T-5 (cargo transit shed) located immediately adjacent to and shoreward of the South Terminal Wharf will be demolished to make room for two, 100-gauge rail-mounted gantry cranes. This is an approximately 456 foot by 150 foot, open wood frame structure. As part of this work the building's on grade asphalt paving and footings may be removed and the paving replaced within this area. 2. South Terminal Wharf Strengthening: This project element will strengthen the remaining 563 foot long main section of the wharf to achieve a 1,000 psf load capacity. Approximately 140-feet of the South Terminal Wharf was strengthened as part of the first phase of this project.This will involve installing approximately(196)new 24- inch diameter and approximately(147) 18-inch diameter steel piles through the existing wharf deck to increase bearing load capacity. Pile caps will be installed beneath the existing deck as well. Approximately 29 new concrete beams will be added. Approximately (25) 12-inch diameter timber fender piles may be removed and replaced with approximately(25) 12-inch diameter steel piles. Pile and cap work at the landward(east) site of the wharf will require temporary relocation of existing riprap material at the top of the slope beneath the wharf. This material will be returned to beneath the wharf following completion of the pile cap work. The footprint of the existing overwater wharf structure will not change. On-wharf stormwater conveyance and treatment also will not change. However,minor repairs to these systems may be necessary if damage occurs during wharf improvements. Stormwater on the wharf is conveyed via trench drains tying into the existing upland stormwater drainage system. All storm water passes through oil/water separators prior to discharge via outfalls to Port Gardner Bay. Construction will begin with the removal of existing pavement and ballast rock,followed by cutting holes into the deck panels. New 24-inch diameter and 18-inch diameter steel piles will then be driven through the holes by vibratory and then impact hammer likely mounted on a land-based crane, although a barge mounted crane could be used. It could take approximately two hours to drive each pile, though actual pile driving time could be approximately 15 minutes of vibratory driving and 10 minutes of impact driving. The total pile driving period will occur over approximately 80 to 110 working days. Along the face of the wharf, fender piles may be removed and replaced using a vibratory hammer only. It will take approximately 30 minutes to drive each fender pile over the course of the same 80 to 110 working day period. Piles will be delivered to the site by barge and overland trucks or both. Piles will be unloaded and set on the wharf, or lifted directly from a marine derrick/barge-mounted crane or staged on a materials barge. Piles will be driven through the riprap bank stabilization that now exists under the wharf. Total area of the pile footprint will be approximately 920 square feet(sf).