“The Price of Sand,” a documentary on the booming frac sand mining industry in Wisconsin and Minnesota, airs at 10 p.m. Friday on Wisconsin Public Television (Ch. 21).

Directed by St. Paul, Minn., native Jim Tittle, the film highlights the quick growth of the frac sand industry in the two states. More than 125 frac sand mines and processing plants have been built in Wisconsin in the past five years.