Geoscience Reference
In-Depth Information
Fig. 17.21
Bivariate plots of corrected deethylatrazine relative to age of groundwater (Steel
et al. 2008 )
found. In shallow groundwater, 61 % of analyzed samples were from agricultural
areas, and 55 % were from urban areas. In 57 % of samples from bed sediments,
discontinued organochlorinated compounds were detected, in comparison with
80 % under urban areas. These findings suggest essentially irreversible retention of
organochlorine pesticides in the soil-subsurface environment.
The occurrence and fate of 45 pesticides and their degradates in groundwater
flow systems within four contrasting agricultural settings from Maryland,
Nebraska, California, and Washington were determined by Steel et al. ( 2008 ). Of
this group, only five parent pesticides and their degradates were detected fre-
quently, comprising two classes of herbicides: triazines and chloroacetanilides. For
example, the atrazine degradation product deethylatrazine was detected in about
half of the 59 wells across all four study areas (Fig. 17.21 ). These data show that
atrazine degradate is still present in the groundwater composition even [60 years
after contamination (groundwater age 1949).
Pharmaceuticals and personal care products (PPCPs), which contaminate soil
and groundwater mostly via land disposal of municipal wastewaters, have been
recognized during the last two decades as ''emerging contaminants'' in environ-
mental chemistry. Heberer ( 2002 ) reviewed the sources and fate of pharmaceuti-
cally active compounds (PhACs) in Europe, South America, and United States,
finding that more than 80 pharmaceutical compounds and drug metabolites were
detected in aquatic environments in concentrations up to the lg/L level. For
example, PhACs such as clofibric acid, carbamazepine, primidone, and iodinated
contrast agents were detected in many groundwater samples. A particular case of
occurrence
and
distribution
of
PhACs
in
groundwater
below
a
landfill
site
Search WWH ::




Custom Search