Circa 1989, this question came up on an EPA National Priority
Superfund Cleanup site, the former Marathon Battery site in Cold
Spring, NY named by George Washington, across the Hudson River from
West Point Military Academy and across Foundry Cove from Constitution
Island, on which fortifications were designed by a Dutch cartographer
to the American revolutionaries, Bernard Romans.

What at first appeared to be the procedure was that any artifacts
found after recording were to placed in a bunker onsite for storage
forever. The focus of a second cleanup, as it was, of cadmium and
nickel (and other) it was negotiated to at first to be processed on
site by only HazMat trained personnel in trailers on the site, and
then by lab personnel without the training as long as that section of
the site not associated with the direct contamination was involved,
i.e., the mitigation of the designed "haul road" to create the earthen
dam in the cove that would be pumped out and the sediments therein
combined with concrete and hauled out on rail, utilizing the former
rail bed that once was used by the historic West Point Foundry to its
large two railroad line dock out into the Hudson River and later by
the Chicago Steel and Bridge Co., constructions of large bridge
sections and skyscraper "parts" painted apparently also in Foundry
Cove. It was also perhaps the first "iron clad" ship was created in
the US.

As the tests in the cove were monitored for hydrocarbons and wipe
tests done on some of the artifacts it was determined that the there
wasn't any threats of contamination and the "bunker" idea was
abandoned.