As manufacturers and suppliers of pavement materials and chemical and mechanical products for modifying, stabilizing, and reducing the permeability of soil and aggregate materials, we have had the opportunity over the past four decades to collaborate with engineers servicing the waste containment industry as well as the engineers servicing the highway construction industry. We have observed that these two branches of the engineering profession have wildly divergent understandings about the role that hydraulic conductivity and permeability play in the performance of the projects they design. There is something to be learned by looking more deeply into this dichotomy.

Designers and builders of highways and roads and the

designers and builders of landfill closure caps have,

for good reason, different approaches to meet their needs and solve their problems.
Yet, the two can instruct each other.