A national study analyzed untreated water
samples from ~1,100 public and 2,400
domestic wells for 55 volatile organic compounds
(VOCs) and found that supplies from
public wells were more vulnerable to VOC
contamination than those from domestic
wells. Analyses of ancillary data identified
natural and anthropogenic variables associated
with occurrence of the most frequently
detected VOCs in public well samples. Perchloroethene
and trichloroethene in public
well water was associated with point sources
and pumping rates, whereas trihalomethanes
and the oxygenate methyl tertiary butyl ether
were not associated with pumping rates and
had a nonpoint source signature.
Study findings should increase awareness
of the risks posed by VOC contamination of
drinking water supply wells and reaffirm the
need for comprehensive wellhead protection
programs. VOC contamination of public well
supplies can be minimized by effective management
practices such as well permitting and
land use planning, construction considerations
such as well depth, and operational factors
such as pumping rate.Includes 26 references, tables, figures.