Kingston's coal gasification plant operated within the downtown area of the City from the mid 1800's through to the 1950's. This plant processed coal to produce coal gas for heating and light throughout the old City. A by-product of the coal gasification process was coal tar. The historic handling and storage of large volumes of coal tar led to the contamination of soils and groundwater in the area of the former plant.
In 1999, the City of Kingston undertook a $2.2 million clean-up of the former coal gasification site by removing huge quantities of contaminated soil and groundwater as well as some unexpected pure coal tar. Since coal tar is generally heavier than water, much of the contamination located deep within fractured limestone bedrock beneath the site could not be removed. Contaminants that had to be left in place were dealt with using a risk based approach where the risk of human exposure and environmental impacts were evaluated for various site development scenarios.
The result was a risk management plan endorsed by the Ministry of the Environment that will control the type of development on the site and allow for long-term monitoring of the site's environmental conditions.