Custom Built Metals

The Custom Built Metals site is located at 233 D Street Northwest, Auburn, Washington.  It is an industrial property consisting of two lots, formerly occupied by the Custom Built Metals Company. The Site was contaminated from historical operations and activities by total petroleum hydrocarbons of diesel, oil and gasoline and associated compounds of benzene, toluene, ethylbenzene, xylenes (BTEX) and naphthalene as well as carcinogenic polycyclic aromatic hydrocarbons (cPAHs), polychlorinated biphenyl (PCBs A1254), cadmium and lead.

Excavation of contaminated soils was conducted in 2001 and 2002. However, contaminated soils remain beneath the warehouse building and possibly the adjoining ramp in Lot 1. Further excavation in those areas was not practicable due to risking significant structural damage to Site buildings and infrastructure.  A restrictive covenant was placed on the property in 2003 to prohibit activities that might result in exposures to the contaminants.

Institutional controls through a restrictive covenant were implemented at the Site as part of the cleanup action, which restricts activities that might result in exposures to the contaminants. Ecology issued a partial sufficiency No Further Action (NFA) determination for the Site in 2008 through the Voluntary Cleanup Program (VCP), and required further action to evaluate groundwater quality at the Site. 

 

Following four consecutive quarters of groundwater monitoring in 2008-2009, a complete NFA was issued in 2010. This NFA determination required additional groundwater monitoring. An additional four consecutive quarters of groundwater monitoring were conducted in 2011-2012 and one groundwater monitoring event was conducted in 2018.

 

No contaminants of concern exceeded cleanup levels during the various monitoring events, with the exception of dissolved lead in one groundwater monitoring well during one of the 2009 sampling events. Since that time, there has been six groundwater monitoring events where lead concentrations were well below the cleanup level.  

 
A periodic review is conducted every five years following a cleanup action when institutional controls are used as part of the remedy, as required by the Model Toxics Control Act (MTCA). The purpose of the periodic review is to evaluate current site conditions and to ensure continued protection of human health and the environment.

The cleanup actions completed at the Site appear to be protective of human health and the environment.
 
The restrictive covenant for the property is in place and continues to be effective in protecting public health from exposure to hazardous substances and protecting the integrity of the cleanup action.
 
Groundwater monitoring was conducted for four consecutive quarters in 2008-2009, four consecutive quarters in 2011-2012, and one event in 2018. No contaminants of concern exceeded MTCA Method A cleanup levels, with the exception of dissolved lead in one groundwater monitoring well during one of the 2009 sampling events. Since that time, there has been six groundwater monitoring events where lead concentrations were well below the MTCA Method A cleanup level. Groundwater monitoring can be discontinued at the Site.
 
Based on this periodic review, Ecology has determined that the requirements of the environmental covenant continue to be met. No additional cleanup actions are required by the property owner at this time. It is the property owner’s responsibility to continue to inspect the Site to assure that the integrity of the remedy is maintained.