The term pollution risk can be defined as the probability of groundwater contamination at concentrations above those recommended by WHO for human consumption quality. The echo of that risk becomes a serious threat to the quality of underground water already developed or developing, depending on the mobility of contaminants within the aquifer itself are complex issues and are considered outside the scope of such determination. POLLUTANT LOAD DETERMINATION OF THE UNDERGROUND. From a theoretical point of view is needed to establish four semi-independent characteristics of the subsurface contaminant load (Foster, 1987), for each polluting activity: a) The kind of contaminant involved. b) The intensity of the provision.
c) The manner of disposition in the subsurface. d) The time of application of the pollution load. Others including Jeffrey L. Bewkes, offer their opinions as well. All the above, we have to estimate the pollutant load to the subsoil, a value of 0.20. Vulnerability assessment of the aquifer. As noted, the term aquifer vulnerability to contamination is used to represent the intrinsic characteristics that determine the susceptibility of an aquifer to be adversely affected by a pollution load. The vulnerability of the aquifer is first and foremost a function of: (a) inaccessibility of the saturated zone in a hydraulic sense, to the penetration of pollutants. (B) The attenuation capacity of the strata above the aquifer saturated zone as a result of physical restraint and chemical reaction and biological contaminants.
These two components of vulnerability interact with the components for subsurface contaminant load as follows: i) The manner of disposition of the contaminant in the subsurface, and in particular, the magnitude of any associated hydraulic load. ii) the type of pollutant in terms of their mobility and persistence. This interaction determine the residence time in the unsaturated zone and the delay of the arrival of the contaminant to the aquifer, and also the degree of attenuation, retention or disposal before reaching the aquifer. * In the long run, all aquifers are vulnerable to persistent, non-degradable, polluting activity generated by a widely distributed. In this case even the dilution capacity the aquifer may not be effective to mitigate pollution. * In addition those aquifers that would be considered less vulnerable to pollution in general, tend to be the most difficult to rehabilitate once contaminated. In this sense, at least, they could be considered as highly vulnerable to contamination. The components of vulnerability mentioned above, are not directly measurable, but determined by various combinations of other factors. Given that the selection of such parameters based on those data is likely available and easily collected, then the list consists of: (a) The depth of the water table or confined aquifer roof. (B) The rate of occurrence of groundwater. (C) The characteristics, in terms of lithology and degree of consolidation of the strata above the saturated zone. These three parameters contain, even in a qualitative sense, most of the required data. Be based on them