"It is Better Not to Use "Validation" and "Verification" Interchangeably in Watershed Modeling" says US EPA

As I was reading Watershed Modeling document available under EPA Watershed Academy today, I came across with the following definitions:

"Model Validation: involves the use of a second, independent set of information to check the model calibration [...]"

wheras

"[M]odel verification is [...] the examination of the numerical technique and computer code to ascertain that it truly represents the conceptual model and that there are no inherent numerical problems with obtaining a solution."

I wanted to post these two definitions on my blog right away because I saw a number of questions in technical discussion groups about the definition of model verification, and interchangeability of verification and validation in watershed modeling.