| Abstract: | A detailed ground-water sampling plan was
developed and executed for 64 monitoring wells in
the city of Independence well field to characterize
ground-water quality in the 10-year zone of contribution.
Samples were collected from monitoring
wells, combined Independence well field pumpage,
and the Missouri River at St. Joseph, Missouri,
from 1998 through 2000.
In 328 ground-water samples from the 64
monitoring wells and combined well field pumpage
samples, specific conductance values ranged
from 511 to 1,690 microsiemens per centimeter at
25 degrees Celsius, pH values ranged from 6.4 to
7.7, water temperature ranged from 11.3 to 23.6
degrees Celsius, and dissolved oxygen concentrations
ranged from 0 to 3.3 milligrams per liter. In
12 samples from the combined well field pumpage
samples, specific conductance values ranged from
558 to 856 microsiemens per centimeter at 25
degrees Celsius, pH values ranged from 6.9 to 7.7,
water temperature ranged from 5.8 to 22.9 degrees
Celsius, and dissolved oxygen concentrations
ranged from 0 to 2.4 milligrams per liter. In 45
Missouri River samples, specific conductance values
ranged from 531 to 830 microsiemens per centimeter
at 25 degrees Celsius, pH ranged from 7.2
to 8.7, water temperature ranged from 0 to 30
degrees Celsius, and dissolved oxygen concentrations
ranged from 5.0 to 17.6 milligrams per liter.
The secondary maximum contaminant level
for sulfate in drinking water was exceeded once in
samples from two monitoring wells, the maximum
contaminant level (MCL) for antimony was
exceeded once in a sample from one monitoring
well, and the MCL for barium was exceeded once
in a sample from one monitoring well. The MCL
for iron was exceeded in samples from all monitoring
wells except two. The MCL for manganese
was exceeded in all samples from monitoring
wells and combined well field pumpage.
Enzyme linked immunoassay methods indicate
total benzene, toluene, ethyl benzene, and
xylene (BTEX) was detected in samples from five
wells. The highest total BTEX concentration was
less than the MCL of toluene, ethyl benzene, or
xylene but greater than the MCL for benzene.
Total BTEX was not detected in samples from any
well more than once. Atrazine was detected in
samples from nine wells, and exceeded the MCL
once in a sample from one well. Alachlor was
detected in samples from 22 wells but the MCL
was never exceeded in any sample.
Samples from five wells analyzed for a large
number of organic compounds indicate concentrations
of volatile organic compounds did not exceed
the MCL for drinking water. No semi-volatile
organic compounds were detected; dieldrin was
detected in one well sample, and no other pesticides,
herbicides, polychlorinated biphenyls, or
polychlorinated napthalenes were detected.
Dissolved ammonia, dissolved nitrite plus
nitrate, dissolved orthophosphorus, alachlor, and
atrazine analyses were used to determine the spatial
and temporal variability of agricultural chemicals
in ground water. Detection frequencies for
dissolved ammonia increased with well depth,
decreased with depth for dissolved nitrite plus
nitrate, and remained relatively constant with depth for dissolved orthophosphorus. Maximum
concentrations of dissolved ammonia, dissolved
nitrite plus nitrate, and dissolved orthophosphorus
were largest in the shallowest wells and decreased
with depth, which may indicate the land surface as
the source. However, median concentrations
increased with depth for dissolved ammonia, were
less than the detection limit for dissolved nitrite
plus nitrate, and decreased with depth for dissolved
orthophosphorus. This pattern does not
indicate a well-defined single source for these constituents.
Dissolved orthophosphorus median concentrations
were similar, but decreased slightly
with depth, and may indicate the land surface as
the source. Seasonal variability of dissolved
ammonia, dissolved nitrite plus nitrate, a |
| Citation Search Results Text: | Ground-water monitoring plan, water quality, and variability of agricultural chemicals in the Missouri River alluvial aquifer near the City of Independence, Missouri, well field, 1998-2000; 2002; WRI; 2002-4096; Kelly, Brian P. |
| Text: | Ground-water monitoring plan, water quality, and variability of agricultural chemicals in the Missouri River alluvial aquifer near the City of Independence, Missouri, well field, 1998-2000; 2002; WRI; 2002-4096; Kelly, Brian P. |
