 Potentially harmful components of this coal tar, in particular polycyclic aromatic hydrocarbons and BTEX (benzene, toluene, ethylbenzene, and xylenes), have been detected in the soil and groundwater.A downward hydraulic gradient prevented the contaminants from spreading, but at the site itself, there was "a current or potential threat to public health and the environment".In addition, a landfill on the southern edge of the park was used to dispose of municipal solid waste.