Hvor kommer sandet til fracking fra?
Hydraulic fracturing
Jack E. Whitten, Steven R. Courtemanche, Andrea R. Jones, Richard E. Penrod og David B. Fogl (Division of Industrial and Medical Nuclear Safety, Office of Nuclear Material Safety and Safeguards) (juni 2000). "Consolidated Guidance About Materials Licenses" (konsolideret vejledning om materialelicenser): Programspecifik vejledning om tilladelser til brøndlogning, sporstoffer og feltundersøgelser af oversvømmelser (NUREG-1556, bind 14)". US Nuclear Regulatory Commission. Hentet 19. april 2012. mærket Frac Sand...Sc-46, Br-82, Ag-110m, Sb-124, Ir-192 CS1 maint: Flere navne: forfatterliste (link)
Hydraulic fracturing
Jack E. Whitten, Steven R. Courtemanche, Andrea R. Jones, Richard E. Penrod, and David B. Fogl (Division of Industrial and Medical Nuclear Safety, Office of Nuclear Material Safety and Safeguards) (June 2000). "Consolidated Guidance About Materials Licenses: Program-Specific Guidance About Well Logging, Tracer, and Field Flood Study Licenses (NUREG-1556, Volume 14)". US Nuclear Regulatory Commission. Retrieved 19 April 2012. labeled Frac Sand...Sc-46, Br-82, Ag-110m, Sb-124, Ir-192 CS1 maint: Multiple names: authors list (link)
Hydraulic fracturing