[MoRoH]

The treatment area for a contaminated site is shown in Figure 1. There are two chemicals of concern; TCE (Trichloroethylene) and PCE (Tetrachloroethylene). The treatment volume, defined by the con- centration contours for the total estimated mass in place are shown in Figure 1 for both chemicals. For the low concentration contour (25,000 / 1,000 ppm), the thickness extends from 30 feet to 60 feet, for the mid contour the extent is from 20 to 60 feet, and for the high contour the extent is from 10 to 60 feet (all below ground surface). The water table is at 10 feet. Other characteristics of the site are summarized in Table 1.

The following questions for Part 1 are:
1)Calculate the initial total mass in grams and volume in litres of TCE and PCE within the treatment volume at 25 ◦ C.
2)Estimate the mass in grams of TCE and PCE dissolved in the ground water within the treatment volume.
3)Provide an explanation as to why it is possible to have clean ground water above a contaminated volume of soil, such as exhibited by the low and mid contours.

So I am an Electrical Engineer by trade but have been outside of school for about a year now and haven't done Chemistry in 4 years. I was given this question as part of a job interview and I am not sure where to start. Not knowing the area is really confusing me. if someone could just point me in the right direction that would be great. thanks.

Here is the figure and givens: http://imgur.com/a/zllid

[Arkcon]

I'm not an engineer at all, so we should wait for someone else to weigh in.  However, you can begin to solve this for yourself -- the flat contour plot describes something of a "cone", not of depth or height but instead of concentration.  You're going to have to find a way to figure out the "volume" of this virtual cone to determine how much contamination is there.  A little tricky for me, given this isn't a regular cone, so I hope you or the other CE's on this board are up to it.