By this time next year, the Yongsan Army Garrison in Seoul will be in the final stage of closing down, as U.S forces shift farther south and consolidate around Pyeongtaek. South Korea intends to convert the site into a series of six parks, but there are unresolved concerns regarding alarming levels of toxic contamination.
In the decade after an oil leak became known in 2001, cleanup efforts by the Seoul Metropolitan Government removed nearly 2,000 tons of oil-contaminated underground water from areas outside of Yongsan.  U.S. Forces Korea (USFK) claimed that it rectified the problem at its source in 2006, yet the level of petroleum hydrocarbon pollution in nearby groundwater continued to grow, multiplying by a factor of nearly thirteen times over the last four years.  The measured concentration of contamination outside Yongsan now stands at well over eight thousand times the Korean government safety standard. It can only be presumed that the situation inside the base is substantially worse.