# What is a contaminant plume?

Understand basic concepts and approaches to slope stabilization for rock slopes and soil slopes.
X. Groundwater – Kehew 11 & 12 (esp. 11)
Basic controls regulating the balance between infiltration & runoff (e.g., plant cover, precipitation intensity, slope, infiltration capacity).
Recharge vs. Discharge, and how the balance between them controls the level of the water table.
Key terms: Saturated vs. Unsaturated zone, aquifer, aquitard, confined vs. unconfined aquifers, artesian aquifers, water table, and potentiometric (piezometric) surface.
Aquifer Types: Alluvial Valley, Buried Valley, Coastal Plain, Tectonic Valley, Bedrock, & Karst. Be prepared to recognize from sketches and describe potential problems.
Darcy’s Law: Q/A = K DH/L
Knowing Darcy’s Law implies knowing the mathematical definitions of: hydraulic head (including elevation head and pressure head), hydraulic gradient, and hydraulic conductivity,
You should expect a problem that will require you to calculate both the Darcy Flux (vd), the seepage velocity (i.e., linear velocity) (vx), and/or the travel time for flow in an aquifer. You should know the difference between Darcy flux and seepage velocity, and how to calculate one from the other if given the porosity.
Be prepared to predict groundwater flow direction and calculate hydraulic gradient from a contour map on the potentiometric surface (or water table) of a given aquifer.
What is a cone of depression, and what parameters would control the size of the cone of depression that would be developed by producing water from a given well.
Societal & Engineering Issues involving Groundwater:
“Groundwater mining” and Induced Subsidence
Groundwater Contamination – What is a contaminant plume? Understand basic concepts for predicting contaminant transport and basic approaches to containing, capturing, and treating contamination. What are the important factors to consider concerning the nature of the contamination? (e.g., point source vs. nonpoint source, aqueous vs. nonaqueous, denser or less dense than water?)
What are the main prevention, treatment or remediation approaches for groundwater contamination? (e.g., containment, pump and treat, air stripping, bioremediation, etc).