While spills and other accidents do happen at industrial plant sites, much of the contamination that accrues through time at manufacturing, refining, and other sorts of industrial operations happens as the result of daily operations – the expected and intended result of product storage, product transfers from rail cars, trucks, drums and other containers into and out of process areas, and on-site disposal practices. Information from historic aerial photographs, maps and other supportive data sources can be central to understanding what materials are present and what processes were used through time, and where at a site.
