Determining Groundwater Contamination

1. Determining Groundwater Contamination

2. Determining Groundwater Contamination Darcy’s Law V = K ΔH ΔL Questions: 2a) ΔH = elevation at storage drum(ft) – elevation threatened well(ft) ΔL = distance from storage drum to well (in miles) ΔH = rate at which groundwater flows (ft/mi) ΔL

3. 2b) Velocity = K ΔH = Final answer in ft/day ΔL K= 100 ft/day 1 mile = 5280 ft 2c) Time = distance = Final answer in years velocity

4. Determining Groundwater Contamination Analysis Question #2 Darcy’s Law V = K ΔH ΔL Questions: 2a) ΔH = 601 ft – 589 ft = 12 ft ΔL = 3150 ft = 0.6 miles (distance from drum to well) 5280 ft/mi ΔH = 12 ft = 20 ft/mi ΔL 0.6 mi

5. 2b) Velocity = K ΔH = (100 ft/day)(20 ft/mi)(1 mi/5,280 ft) = 0.4 ft/day ΔL K= 100 ft/day 1 mile = 5280 ft 2c) Time = distance = (3,150 ft)(1 day/0.4 ft)(1 yr/365 days) = 21.6 yrs velocity

6. Practice Problem #1 • ΔH = elevation at storage drum(ft) – elevation threatened well(ft) ΔH = 53 ft – 49 ft = 4ft ΔL = distance from storage drum to well *this needs to be in miles* ΔL = 133 ft = 0.025 miles 5,280 ft/mi ΔH = rate at which groundwater flows (ft/mi) = 4 ft ΔL 0.025 mi = 160 ft/mi

7. b) V = K ΔH ΔL V = 10 ft 160 ft 1 mile day mile 5,280 ft = 0.30 ft/day c) Time = distance (ft) velocity (ft/day) Time = 133 ft 1 day 1 yr 0.30 ft 365 days = 1.21 years

8. Practice Problem #2 • ΔH = elevation at storage drum(ft) – elevation threatened well(ft) ΔH = 70 ft – 50 ft = 20 ft ΔL = distance from storage drum to well *this needs to be in miles* ΔL = 121 ft = 0.0229 miles 5,280 ft/mi ΔH = rate at which groundwater flows (ft/mi) = 20 ft ΔL 0.0229 mi = 873.36 ft/mi

9. b) V = K ΔH ΔL V = 12 ft 873.36 ft 1 mile day mile 5,280 ft = 1.98 ft/day c) Time = distance (ft) velocity (ft/day) Time = 121 ft 1 day 1 yr 1.98 ft 365 days = 0.167 years