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| Albemarle-Pamlico NAWQA |
| ALBE | NAWQA | DATA | PUBLICATIONS | CONTACTS |
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| Albemarle-Pamlico NAWQA |
| ALBE | NAWQA | DATA | PUBLICATIONS | CONTACTS |
Albemarle-Pamlico Study (ALBE), National Water-Quality Study (NAWQA)
The areal ground-water quality studies of the Albemarle-Pamlico Drainage describe general characteristics of shallow ground water (ground water that occurs within 50 feet of the land surface) and specific characteristics of shallow ground water under selected land uses. On a National basis, shallow ground water was selected because it is most susceptible to contamination from the land surface. Several deep public supply wells were also sampled in areas of cones of depression caused by pumping . This was done to determine if deep supply wells appeared to be intercepting contaminants introduced in water from shallow aquifers.
Ground-water quality was investigated in the Albemarle-Pamlico Study Unit through a statistically based land-use survey and study unit survey and a process-oriented flow-path study, which are described below. A flow-path study also was conducted on one site to investigate causal factors associated with ground-water quality. The well locations are shown in Figure 1.
Figure
1.-- Locations of wells sampled in the ALBE
study.
The land-use survey focused on agricultural land use. Urban uses also were investigated, but results were not included because of sampling problems encountered during the study. These results will be discussed in a planned report. Because corn and soybean agriculture is so important in the Albemarle-Pamlico Drainage and is representative of this type of agriculture in the eastern United States, this particular land use was selected to investigate possible regional and national water-quality effects. Twenty-six sites across the Coastal Plain, which were used for growing corn and soybeans, were randomly selected. Wells were installed on 21 of these sites. Another 5 shallow supply wells in these same areas were sampled to determine if contaminants from the fields appeared to be reaching nearby domestic supply wells.
The study unit survey wells were randomly selected to represent general shallow ground-water quality in the Coastal Plain without a targeted land use. These wells were used to compare water-quality data from targeted land-use wells in the same area to evaluate possible effects associated with the particular land use investigated. Wells that could be included for selection were those equipped with submersible pumps and good well-construction and location information. Many of these wells were typically existing USGS or State observation wells used for long-term water-level monitoring. Most wells occured in areas of recharge and none were sited in stream discharge areas. Several were shallow supply wells, which were equipped with submersible pumps. About 7 deep public-supply wells were also sampled in the vicinity of known pumping cones to evaluate possible pumping-induced contamination.
DATA- Dataset to download and more detailed description of the ground-water studies.
Three special synoptic studies were designed to investigate the relation between ground-water and surface-water quality. These studies included the collection of ground water from the stream bed, bed sediment, and surface-water samples.
SYNOPTIC DATA- Datasets to download and a description of the synoptic studies.
How were the samples collected?
Ground-water samples were collected according to protocols established by NAWQA (Wayne Lapham, written communication, July 1995). In general, wells were sampled using a submersible pump equipped with Teflon discharge tubing. For water-supply wells equipped with a submersible pump, the spigot was connected to the flow-through tubing and processed either through the flow-through chamber or collection chamber. All wells were pumped until 3-5 well volumes or more had been purged from the well. Field parameters were measured in a flow-through chamber. Analyses of nutrients were performed according to methods presented in Fishman (1993). All sample collection was performed using continuous flow directly from the well into sample collection and preservation chambers. Pesticides were collected into baked brown glass 1-liter (L) bottles after filtering though a 0.4-µ glass fiber filter. All pesticide samples were analyzed according to methods published in Zaugg and others (1995).
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