Nevada Revised Statutes Title 40. Public Health and Safety § 445B.420. Limitations on duration;  annual review

(a) If the variance is granted because no practical means is known or available for prevention, abatement or control of the air pollution involved, the variance shall continue only until such means become known and available.

(b) If the variance is granted because compliance with applicable regulations will require measures which, because of extent or cost, must be spread over a period of time, the variance shall be granted only for the requisite period as determined by the Commission, and shall specify the time when the successive steps are to be taken.

(c) If the variance is granted for any other reason, it shall be granted for 1 year or less.