Complex sentence: In 2006, the mercury processing building as well as a variety of mercury-laden soils were removed.In 2007, the EPA conducted a Remedial Investigation in order to further characterize the nature and extent of mercury in the site's soil and water.
Split into simpler sentences: In 2006, EPA continued their efforts by removing the mercury processing building as well as a variety of mercury-laden soils. Moreover, in 2007, they conducted a Remedial Investigation in order to further characterize the nature and extent of mercury in the site's soil and water.