Almost eight years after plans were completed to clean up the LCP Chemicals Inc. Superfund site in Linden, the Environmental Protection Agency announced that work would begin. The EPA said Wednesday that buildings would be demolished, paving the way to address the site’s mercury-contaminated soil and groundwater. The demolition work is expected to end this summer. That’s the first phase of the then-$36.5 million plan announced in February 2014. At the time, the EPA said it would take three to five years for work to begin on what was one of the most toxic sites in Union County. The site of the …