Aquifer discharged area

Next we look at how temperature gradients along an aquifer might affect the silica content of flowing groundwater. We consider a symmetrical aquifer that descends from a recharge area at the surface to a depth of about 2 km and then ascends to a discharge area. Temperature in the calculation varies linearly from 20 °C at the surface to 80 °C at the aquifer s maximum depth. 

Fig. 12.10 Chlorine-36 as a function of chlorine for the Murray-Malee study. Symbols designate the reported formation from which the water was sampled Murray group (+), Murray group at discharge areas (squares), Renmark group (circles), Pliocene aquifer (triangle). The local intake line was based on unconfined water samples. The data fall on this line or beneath it, indicating old ages.

The nearest possible discharge area of the lower aquifer, the ocean, was about 160 km south of the selected injection area. Thus the injection site was remote from recharge and discharge points, and the injected aquifer was saline and isolated from the overlying aquifer. 

Ground Water Geochemistry. Ground water from the lower aquifer in the lower Perch Lake Basin at the Chalk River Nuclear Laboratories, Figure 2, was used for field elution studies to provide water of different redox characteristics. Water from piezometer "0" in the transition area, and from KNEW in the discharge area was used as being representative of "neutral" and... 

Traditionally, the use of analytical models in environmental tracer studies has been far more widespread than numerical models. There are a number of reasons for this. Analytical models are easier to use and manipulate than numerical ones they require less hydrodynamic information and/or field data and the time required to build a transport model is much less than for a numerical model. Multiple examples of such models can be found in the literature for various tracers H, He, C, and C1 (e.g., Castro et al., 2000 Nolte et al., 1991 Schlosser et al., 1989 Solomon et al., 1996 Stute et al., 1992b Torgersen and Ivey, 1985). Generally, these models are either applied to a single aquifer in porous or fractured media or to one particular area within the aquifer such as recharge or discharge areas. 

Bohlke J. K., Wanty R., Tuttle M., Dehn G., and Landon M. (2002) Denitrification in the recharge area and discharge area of a transient agricultural nitrate plume in a glacial sand outwash aquifer, Minnesota. Water Resour. Res. 38(7), doi 10.1029/2001WR000663. 

Figure 24. Variation of the He content as a function of depth in the discharge area of the PL2 aquifer. Great Hungarian Plain (after Stute et al. 1992). From the He gradient and the water velocity, these authors derived a " He crustal flux one order of magnitude lower than that due to degassing of the whole continental crast.

Protects water quality in lakes, rivers, aquifers, and coastal areas by regulating ivastewater discharges monitoring bodies of water, and controlling surface runoff... 

A traditional approach to aquifer remediation is to remove the contaminated water by pumping, treating the water at the surface, and then either discharging it or reinjecting it back into the aquifer. When the recovery wells are properly located, this approach has the advantage of creating a capture area which contains and prevents the contamination from migrating. 

---