Natural organic compounds found in all surface and groundwaters. These compounds MAY react with halogens (such as chlorine) to form trihalomethanes (try-HAL-o-METH-hanes) (THMs); they MUST be present in order for THMs to form.
PRECURSOR, THM (PRE-CURSE-OR)
Meaning of PRECURSOR, THM (PRE-CURSE-OR) in English
Environmental engineering English vocabulary. Английский словарь экологического инжиниринга. 2012