"Baseline water quality" means the existing water quality for each parameter of concern in the surface water or segment thereof, which has been established by the Department following the collection of not less than 20 samples collected approximately every 90 days over a period of not less than 5 years at a location designated by the Department.
Nev. Admin. Code § 445A.Sec. 4.2
NRS 445A.425, 445A.465