Targus was retained to perform an environmental site assessment (Phase I ESA and additional non-ASTM services) of an approximately six acre property improved with two mixed-use multifamily buildings. The subject property was formerly part of the larger Asarco Tacoma Smelter that operated from 1890 until 1986, first as a lead smelter and later as a copper smelter.
Targus reviewed numerous regulatory documents and prior reports with information pertaining to the Asarco Tacoma Smelter. During it’s time of operation, the smelter used high temperature furnaces to extract desired metals from raw ore, discharging metal particulates (primarily arsenic and lead) into the air which settled on surrounding land (estimated to impact approximately 1,000 square miles). Additionally, an estimated 15 million tons of slag, a waste byproduct of the smelting process containing various metals, was poured into the neighboring Commencement Bay as a hot liquid to cool and harden, resulting in an artificial shoreline where the subject property now resides.
In 1983, the Commencement Bay Nearshore/ Tideflats Site was added to United States Environmental Protection Agency’s (EPA’s) list of Superfund sites (National Priority List [NPL]) due to the metal and organics impact to soil, groundwater, and the bay from historical operation of the smelter. Asarco was identified by the EPA as the responsible party for the contamination and was ordered to perform immediate site stabilization and conduct Remedial Investigation and Feasibility Studies. Asarco entered into subsequent Consent Decrees with the EPA, agreeing to conduct remedial actions related to contamination resultant of the smelter operations.
With the objective of developing a master planned mixed-use neighborhood, of which the subject property was a part, the smelter site was purchased in 2006 with the purchaser agreeing to facilitate remaining cleanup efforts by the seller at the 97-acre smelter site. At the time of Targus’ assessment, the owner had overseen numerous remedial efforts, including removal of source materials (waste material and highly contaminated soil) to a lined and monitored containment facility, installation of an impervious cap, surface water controls, shoreline armoring, and habitat restoration in selected inter-tidal areas.
Targus contacted the EPA Remedial Manager of the NPL site, confirming that the remediation applicable to the subject property consisted of an impervious cap and groundwater use restrictions, both of which were already in place. The subject property had Certificates of Completion as well as Approval of Occupancy issued by the EPA. Targus confirmed that upon purchase of the subject property, the new owner would be required to enter into an agreement with the EPA that would require ongoing maintenance and monitoring of the impervious cap on the subject property in perpetuity. Targus also researched potential vapor issues in relation to the former uses at the NPL site and surrounding area identifying that known methane vapors related to decomposing wood waste from a former sawmill as well as dimethylaniline impact from a former liquid sulfur dioxide plant were located to the southeast of the subject property and that no indications of vapor issues were present on the subject property.
Remedial efforts at the subject property were judged to be complete based on review of available resources and information obtained from interviews conducted. The subject property development required institutional and engineering controls including installation and maintenance of an impervious cap, and activity use limitations including the prohibition of groundwater use/ installation of wells. Soil and groundwater impacts at the subject property from the historical smelter facility were therefore considered to be a controlled recognized environmental condition.
Targus provided a thorough report to the client, documenting our file review, interviews, observations, reasoning, and conclusions.