STUDY UNIT DESIGN
Stream Chemistry
A network of 10 stream sites was sampled for various chemical constituents and physical properties from March 1996 through February 1998 (fig. 35, table 3). Sampling was done over a range of streamflows. Sites were sampled 18–32 times per year; intensive sites were sampled more frequently than basic sites (table 3).
Assessments of contaminants in streambed sediments and fish tissue were made at the 10 fixed streams sites and at one to five additional sites. Sediment samples were collected and sieved in the field. Whole fish were collected and analyzed for concentrations of organochlorine compounds. Fish livers were analyzed for trace-element concentrations.
Stream Ecology
Sampling was done at least once at 10 sites where water samples were collected. Multiple-year and multiple-reach sampling was done at three sites (table 3). Stream reaches ranged from 200 to 500 meters in length.
Fish surveys involved electrofishing and seining. Macroinvertebrates and algae were sampled from natural substrates. Habitats were assessed by identifying and mapping riparian vegetation and measuring geomorphic features of stream channels. Samples of bed and bank materials were collected and analyzed for grain size.
Ground-Water Chemistry
Two reconnaissance-type studies were done. The first focused on the fractured-rock aquifers of the coal-bearing Pittsburgh Series rocks of middle and late Pennsylvanian age. The second was set in the coarse- and fine-grained glaciofluvial deposits of the valley-fill aquifers in the northern area of the Allegheny River Basin (fig. 27). An additional study that focused on mining land use involved sampling of wells that drew water from the fractured-rock aquifers and that were near surface coal mines where mining and reclamation efforts have been completed. The quality of these samples was compared to that of water from 15 wells sampled in unmined areas of the same aquifers.
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| Figure 35. Stream and ground-water sampling sites in the Lake Erie-Lake Saint Clair Drainages, 1996–98. |
| TABLE 3. SUMMARY OF DATA COLLECTION IN THE LAKE ERIE-LAKE SAINT CLAIR DRAINAGES, 1996-98 |
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|---|---|---|---|---|
| Study component |
What data were collected and why |
Types of sites sampled |
Number of sites |
Sampling frequency and period |
| Stream Chemistry |
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| Contaminants in stream-water--basic sites |
Streamflow, pH, specific conductance, temperature and concentrations of nitrogen and phosphorus compounds, major ions, organic carbon, suspended sediment, herbicides, and E. coli were measured to determine occurrence and distribution of contaminants and other constituents |
Streams draining areas ranging in size from 132 square miles to 1,230 square miles reflecting agricultural, urban, and mixed land uses. |
6 |
Monthly, plus storms and low flows from March 1996 to February 1998 |
| Contaminants in stream-water--intensive sites |
Physical properties and chemical and microbiological constituents mentioned above plus insecticides and VOCs. |
Streams draining areas ranging from 310 square miles to 6,330 square miles reflecting agricultural, urban, and mixed land uses. |
4 |
Weekly to monthly, plus storms and low flows from October 1996 to September 1997, bracketed by monthly plus storms from March 1996 to February 1998 |
| Contaminants in streambed sediment |
Concentrations as dry weight of trace elements, semivolatile organic compounds, organochlorine compounds, and percent organic content. Determined to assess occurrence and distribution of contaminants. |
Shallow depositional zones in a 300-meter reach at all 10 sites sampled for stream- water chemistry and at 5 additional sites |
15 |
One to three times in June-October, 1996-98 |
| Contaminants in fish tissue |
Concentrations of trace elements in fish liver and organochlorine compounds, such as PCBs and organochlorine pesticides, in fish tissue were analyzed to determine occurrence and distribution. |
Resident fish such as carp, rock bass, and hog suckers at all sites sampled for stream-water chemistry and at one additional site |
15 |
One to three times in June-October, 1996-98 |
| Stream Ecology |
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| Aquatic biota at stream sites |
Community composition of aquatic macroinvertebrates, algae, fish and stream habitat were surveyed to determine effects of water quality on aquatic biota. |
Sites co-located with basic and intensive stream-water chemistry sites and at three additional sites |
10 |
One to three times in June-October in 1996-98
|
| Ground-Water Chemistry |
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| Subunit survey |
Water level, pH, specific conductance, temperature and concentrations of nitrogen and phosphorus compounds, major ions, VOCs, organic carbon, insecticides, herbicides, herbicide degradates, radon, and tritium were measured to determine the quality of an aquifer that is an important source of drinking water. |
Domestic wells in the northwestern part of the Study Unit. Eighteen of the wells are co-located with monitor wells of the agricultural land-use study. |
28 |
Once, June-August 1998 |
| Agricultural land-use study |
Above measurements and compounds (except VOCs and radon) to determine the effects of agricultural land use on shallow ground water. |
Monitor wells in agricultural areas in northwestern part of Study Unit. |
30 |
Once, June-August, 1998 |
| Urban land-use study |
Above compounds (plus VOCs and radon) to determine effects of recent residential development on shallow ground water.
|
Monitor wells in new residential areas near Detroit, Mich. |
30 |
Once, September-December 1996 |
| Special Study |
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| Urban drinking-water study |
Same as for Subunit survey |
Domestic wells co-located with urban land- use wells in new residential areas near Detroit. |
28 |
Once, May-July 1997 |
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