Water Chemistry of the Unconsolidated
Deposits of the Metro East,
HERBICIDES, THEIR TRANSFORMATION
PRODUCTS, AND ANTIBIOTICS:
GROUND-WATER QUALITY DATA FOR THE METRO EAST, ILLINOIS AREA
During August-October 2005, the
chemicals in ground
water in the
(often referred
to as the Metro East area). Samples from 6 monitoring wells and 2 public-supply
wells were
analyzed for 6 acetamide herbicides (acetochlor,
alachlor, dimethenamid, flufenacet, metolachlor, and
propachlor) and 26 of
their transformation products (often referred to as degradates
or metabolites).
Additionally, a sample from one monitoring
well in the area was analyzed for antibiotic compounds.
The wells were selected to provide
increased understanding of the extent of these compounds in the source
waters used for
public supply in the region. Past
analyses for acetamide transformation products in the
area
is limited to a single set of samples from three additional
public-supply wells (Mills and McMillan, 2004).
Review of available data indicates no
previous antibiotic analyses. All wells were open to unconsolidated
deposits that range
in composition from clay and silt to sand and gravel. Well depths ranged from
about 17
to 112 feet;
depth to ground water ranged from about 3.5 to 33.2 feet. The public-supply wells and two
of the
monitoring wells were open to the alluvial aquifer underlying the part of the
Metro East area
referred to as the
American Bottoms. All the wells sampled for herbicides were located within 0.25
mile of
land in current
or past row-crop production. The well sampled for antibiotics was open to
generally fine-
grained deposits
that compose the uplands west of the American Bottoms; the well is located
within 100 yards
of a sanitary
sewer main, a commercial development, a residential street and subdivision, and
a state highway.
Details regarding sampling methodology
are given in Kolpin and Burkart (1991) and Mills and
McMillan (2002).
Water samples were collected using
field-parameter stabilization and volumetric purge criteria to ensure
samples were
representative of the aquifer water quality. Samples from water-supply wells
were collected
before water treatment
(chlorination, for example). All samples were filtered through a 0.7 micron
baked
glass-fiber filter,
chilled immediately to 4 degrees Centigrade, and shipped to the laboratory
within 2 days of
collection.
Analyses were made at the USGS Organic
Geochemistry Research Laboratory in
compounds were
analyzed by liquid chromatography/mass spectrometry (LC/MS) (Zimmerman and
others, 2000;
Lee and others, 2001; and Lee and Strahan,
2003), as were antibiotic compounds (Lindsey and others, 2001).
The acetamide-herbicide
and antibiotic analytical results from this study are given below.
Additionally, related
herbicide results from
these and other monitoring wells (William S. Morrow,
commun., 2006) and public-supply
wells in the area (Mills and McMillan, 2004) are given.
References:
Kolpin, D.W., and Burkhart, M.R., 1991, Workplan for regional reconnaissance for selected
herbicides and nitrate in ground water of the mid-continent
Lee, E.A., Kish, J.L., Zimmerman, L.R.,
and Thurman, E.M., 2001, Method of analysis by the
U.S. Geological Survey Organic
Geochemistry Research Group - update and additions
to the determination of chloroacetanilide
herbicide degradation compounds in water
using high-performance liquid
chromatography/mass spectrometry:
Survey Open-File Report 01-10, 17 p.
Lee, E.A. and Strahan,
A.P., 2003, Methods of analysis by the
Geochemistry
Research Group - determination of acetamide
herbicides and their
degradation products in water using online solid-phase
extraction and high-performance
liquid chromatography/mass spectrometry:
03-173,
17 p.
Lindsey, M.E., Meyer, M.T., and Thurman,
E.M., 2001, Analysis of trace levels of sulfonamide
and tetracycline antimicrobials in groundwater and surface
water using solid-phase
extraction and Liquid Chromatography/Mass Spectrometry,
Analytical Chemistry, v. 74,
p.
4640-4646.
Mills, P.C., and McMillan, W.D., 2004,
Herbicides and their transformation products in source-
water aquifers tapped by public-supply wells in
Survey
Water-Resources Investigations Report 03-4226, 57 p.
Zimmerman, L.R., Hostetler, K.A., and
Thurman, E.M., 2000, Method of analysis by the
U.S. Geological Survey Organic
Geochemistry Research Group - determination of
chloroacetanilide
herbicides in water using high-performance liquid chromatography-
diode
array detection and high-performance liquid chromatography/mass spectrometry: