I think they both considered it as a given. "Chloroform evaporates very quickly when exposed to air. Chloroform also dissolves easily in water, but does not stick to the soil very well. This means that it can travel down through soil to groundwater where it can enter a water supply.
Chloroform lasts for a long time in both the air and in groundwater. Most chloroform in the air eventually breaks down, but this process is slow. The breakdown products in air include phosgene, which is more toxic than chloroform, and hydrogen chloride, which is also toxic."
http://www.atsdr.cdc.gov/phs/phs.asp?id=51&tid=16
"Long" is according to this site many
years for groundwater, doesn't mention how long precisely for air or other surfaces like carpet though.
http://www.dhs.wisconsin.gov/eh/chemfs/fs/chloroform.htm