Right next to the Main Street Ferry Terminal, between the Oakland Estuary and the Dog Park, is the Navy’s cleanup Site 28, also known as the Todd Shipyards site. The contamination at this site — copper and arsenic, and to a lesser extent lead and hydrocarbons — was not the result of Navy activities, even though the Navy owns the property.
Filling in the land with estuary dredge soil contaminated with hydrocarbons from the coal gasification plant that once operated in Oakland was likely responsible for the petroleum-related hydrocarbons in the ground. The Alameda Mole Railroad operated along this route from 1883 until 1939 and was also a possible contributor to the hydrocarbon residue in the soil. Non-Navy shipbuilding and repair between 1941 and the 1980s was responsible for lead, arsenic, and copper contamination.
According to the Navy fact sheet, “The property was leased to various entities for non-Navy shipbuilding and repair between 1941 and 1970. The property was purchased from the Navy in 1970 by the Todd Shipyards Corporation, which used the land as an extension of its adjoining shipyard property until 1983, when the property was then sold to Alameda Gateway Limited. The IR Site 28 portion of the former shipyard reverted to Navy ownership in 1995.”
Paint used on ships
The copper contamination came from paint used on the bottoms of ships. The paint was an anti-fouling paint that served to prevent the growth of barnacles. Copper in the paint acted as the biocide, which is why possible leaching into the estuary is a big concern.
Emerging cleanup technology
Even though the Navy did not cause the contamination, they are responsible for the cleanup, which it performed in 2010. They are also responsible for monitoring the groundwater for 10 years to make sure their methods are permanent. Some of the methods used here were straightforward: Digging up soil and replacing with new soil.
The copper at groundwater level, however, is being dealt with by an emerging technology called metals immobilization. In this process a proprietary non-toxic compound is injected into the ground to bind to the copper and cause it to be absorbed into soil particles, which will prevent it from leaching into the estuary and harming aquatic life. Hence, the term immobilization – the copper is no longer mobile, or able to move. Water and natural microbes in the ground are what activates this immobilization compound. A helpful byproduct of this reaction is that food (carbon) for natural microbes is released, further enhancing the effectiveness of this process.
So-called emerging cleanup technologies are halfway between experimental and mainstream. They have been proven effective in the short term, or in some locations, but have not been in widespread use long enough to be considered 100% effective in every soil type. No one knows for certain if the binding effect will hold, but pilot lab tests were done on soil from Site 28, and the Navy and regulators fully expect it will work. If groundwater monitoring indicates that it’s not working, the Navy will have to come up with another plan since there is no statute of limitations on their responsibility for cleanup.