Northlake Shipyard

On March 25th, 2014, the final bucket of clean sand was dropped into Lake Union at Northlake Shipyard.  The first barge carrying sand arrived at Lake Union in early March.  Just a few weeks later,  2.5 acres of lake bottom at Northlake Shipyard was covered with 3,000 tons of clean sand. That is good news for the lake bottom-dwelling critters.  They now have a new clean habitat.  The sand cap will also protect the water from contamination that may remain after the dredging interim action was completed.



Ecology began removing the arsenic contaminated sandblast grit from the NLSY in early December. By the end of the process, Ecology’s contractor, Redside Construction, removed more than 10,161 tons of dredged material – more than the entire weight of the Space Needle and its foundation. The contaminated sediment material was sent offsite for safe disposal. In the process of removing the sediment, large debris like logs, cables, and sections of vessels from historic operations was pulled from the lake. The scrap metal alone weighed 23 tons or the equivalent of 13 cars. The goal of the project was to remove the arsenic contaminated sandblast grit used by the previous owner and place a protective sand cap over the area.  Mission accomplished.

The Northlake Shipyard Site is located in Lake Union at 1441 North Northlake Way, Seattle, Washington 98103.

The Northlake Shipyard site is located in the City of Seattle, King County, Washington. Several studies have been completed around the Site to evaluate Gas Works Park and Lake Union soil, sediment and groundwater conditions. Data from these studies detected a wide range of contaminants. Total PAH concentrations in surface sediments ranged from 9 parts per million (ppm) to 3,749 ppm. PCBs were detected in surface sediment samples at concentrations up to 650 parts per billion. Metals detected in sediment samples near the Site included antimony up to 420 ppm, arsenic up to 2,920 ppm, cadmium up to 9 ppm, copper up to 4,180 ppm, lead up to 2,550 ppm, mercury up to 3 ppm, nickel up to 131 ppm, silver up to 8 ppm and zinc up to 9,440 ppm.

Northlake shipyard entered into a Prospective Purchaser Consent Decree (PPCD) prior to purchasing the Site through bankruptcy proceedings from United Marine. Northlake entered into the PPCD to avoid incurring potential liability for present contamination at the Site. The primary component of the PPCD is to require Northlake to make cash payments to a trust fund established for the cleanup of the contamination caused by past activities at the Site. The trust fund will be used to cover Ecology’s direct remedial activities costs, remedial activity oversight costs, and the costs of a post-cleanup evaluation.

A deed restriction was recorded for the property in 1998 to assure that the terms of the decree run with the land.