Problem Description Safe drinking water is a very important resource that most people don t think about very often. However, this subject is very important to environmental engineers. In order to maintain a sufficient supply of safe drinking water, a deep understanding of groundwater contamination is necessary. Contaminant movement in groundwater is due mainly to advection and dispersion . Advection is the mass transport of contaminants, in which the rate and direction are the same as that of the groundwater that they are dissolved in.
Dispersion causes a mixing zone between adjacent fluids due to diffusion and mechanical dispersion.
The diffusion is due to random molecular motion and mixing due to the groundwater velocity in heterogeneous materials. This town is in close proximity to an old waste disposal site, and the mayor is claiming that the lead levels are due to aquifer contamination by wastes emanating from the site. The site had been used for most of the 20 th century, at which time the environment and its safety was not an issue. Our engineering firm has been contracted by the mayor to perform groundwater contaminant analysis. The old waste disposal site is located on the top slope of an elevated terrain feature.