Isolated on a high plateau, the Los Alamos National Laboratory seemed an ideal place to store a bomb factory's deadly debris. But the heavily fractured mountains haven't contained the waste, some of which has trickled down hundreds of feet to the edge of the Rio Grande, one of the most important water sources in the Southwest … monitoring of runoff in canyons that drain into the river has found unsafe concentrations of organic compounds such as perchlorate, an ingredient in rocket propellent, and various radioactive byproducts of nuclear fission. “Much surface contamination … moves down into groundwater. That subterranean migration poses the greatest long-term danger to drinking-water wells and ultimately the Rio Grande. One of the canyons where radioactive waste has been found joins the Rio Grande just three miles above a diversion project the city of Santa Fe is building to capture nearly 3 billion gallons of water annually from the river” a. Assuming homogeneous hydraulic conductivity, no pumping wells, and steady state conditions, identify the governing equation and boundary conditions that would be used to approximate the rate of groundwater flow from a surface deposit of contaminated water to a nearby river canyon. Identify all terms and state all assumptions.
b. recognizing that the material is both porous and fractured, how might you characterize the hydraulic conductivity given the mean grain size and the average thickness of the fractures ?