Muldoon, Maureen A.; Madison, Frederick William, 1937-; Lowery, Birl / Variability of nitrate loading and determination of monitoring frequency for a shallow sandy aquifer, Arena, Wisconsin
Field setting and methods, pp. 2-9 PDF (2.3 MB)
the growing season. Monitoring was initiated in the spring of 1996 and continued until summer 1998; site visits were conducted approximately every two weeks over this time period. Instrumentation malfunctions in 1996 lead to an incomplete data set for both water levels and water quality. A relatively continuous record of water levels was collected from March 1997 to July 1998. Water-quality data are available during the entire 1997 growing season and during the spring recharge event of 1998. A nest of three 2-inch piezometers was installed on the western edge of the research site in November of 1995 (figure 2) using the Wisconsin Geological and Natural History Survey's drill rig. Previously collected water-level data (Fermanich, unpublished data) indicated that the water table fluctuated from 8.3 to 12.1 ft below ground surface. Two shallow piezometers, with 5-ft screens, were installed across the zone of water-table fluctuations. The third piezometer was completed 5 ft below the shallow piezometers. Piezometers were installed though hollow-stem augers with an inner diameter of four inches. Construction details for the piezometers are shown in figure 3. Water-level monitoring was initiated in the spring of 1996. Two 15-psi pressure transducers, wired to a datalogger, were used to monitor water levels in piezometers 2 (shallow) and 3 (deep). Water levels were sampled every 5 minutes and average hourly water levels were recorded in the data files. Data were downloaded at 2-week intervals and field-measured water levels were used to calibrate the transducer readings. Water-level data are included in the Appendix.