Q4 An enviornmental site assessment has been carried out to delianate the extent of shallow aquifer contamination with CCl4. The sampling locations are shown in the figure below. Each grid is 25 x 25 m2. The liquid phase CCl4 concentrations (in ug/L) are tabulated in the table below. The groundwater table is located at a depth of 2.5 m. h a Location a b Depth (m) 10 50 30 300 650 5 20 10 180 340 60 30 3 15 d e f 15 75 65 350 700 110 70 7 30 90 04 g h 55 5 25 (a) Estimate the average CCl4 concentration in the shallow aquifer. (b) If the aquifer has 1 % soil organic matter of 58% carbon, a dry density of 2100 kg/m3, and a porosity of 0.35, estimate the total amount of CCl4 present (in kg) if there is no free product found in the aquifer. The value of Koc for CCl4 at the prevalent groundwater temperature is 338 L/kg. Q4 An enviornmental site assessment has been carried out to delianate the extent of shallow aquifer contamination with CCl4. The sampling locations are shown in the figure below. Each grid is 25 x 25 m2. The liquid phase CCl4 concentrations (in ug/L) are tabulated in the table below. The groundwater table is located at a depth of 2.5 m. h a Location a b Depth (m) 10 50 30 300 650 5 20 10 180 340 60 30 3 15 d e f 15 75 65 350 700 110 70 7 30 90 04 g h 55 5 25 (a) Estimate the average CCl4 concentration in the shallow aquifer. (b) If the aquifer has 1 % soil organic matter of 58% carbon, a dry density of 2100 kg/m3, and a porosity of 0.35, estimate the total amount of CCl4 present (in kg) if there is no free product found in the aquifer. The value of Koc for CCl4 at the prevalent groundwater temperature is 338 L/kg