Envisioned by Richard Haag, Seattle's award-winning Gas Works Park was one of the earliest remediated sites in which materials of environmental concern were kept onsite and incorporated into the design of the project. A gasification plant occupied this space between 1906 and 1956 leaving hydrocarbons and tar. Were it not for the recycling of much of the plant building and surrounding soils, this project could not have been completed because of the great cost of removal.