fur ▁dio x ide , ▁nit ro gen ▁ox ide , ▁and ▁mer cur y ▁em issions ▁of ▁power ▁plants ▁over ▁the ▁course ▁of ▁ 1 5 ▁years , ▁while ▁saving ▁consum ers ▁millions ▁of ▁dollars . ▁ ▁Among ▁other ▁things , ▁the ▁Clear ▁Sk ies ▁Act ▁states ▁that ▁it ▁would : ▁ ▁C ut ▁mer cur y ▁em issions ▁by ▁ 6 9 ▁percent , ▁- ▁the ▁first - ever ▁national ▁cap ▁on ▁mer cur y ▁em issions . ▁Em issions ▁will ▁be ▁cut ▁from ▁current ▁em issions ▁of ▁ 4 8 ▁tons ▁to ▁a ▁cap ▁of ▁ 2 6 ▁tons ▁in ▁ 2 0 1 0 , ▁and ▁ 1 5 ▁tons ▁in ▁ 2 0 1 8 . ▁ ▁C ut ▁em issions ▁of ▁nit ro gen ▁ox ide ▁( NO x ) ▁by ▁ 6 7 ▁percent , ▁from ▁em issions ▁of ▁ 5 ▁million ▁tons ▁to ▁a ▁cap ▁of ▁ 2 . 1 ▁million ▁tons ▁in ▁ 2 0 0 8 , ▁and ▁to ▁ 1 . 7 ▁million ▁tons ▁in ▁ 2 0 1 8 ▁ ▁C ut ▁sul fur ▁dio x ide ▁( SO 2 ) ▁em issions ▁by ▁ 7 3 ▁percent , ▁from ▁em issions ▁of ▁ 1 1 ▁million ▁tons ▁to ▁a ▁cap ▁of ▁ 4 . 5 ▁million ▁tons ▁in ▁ 2 0 1 0 , ▁and ▁ 3 ▁million ▁tons ▁in ▁ 2 0 1 8 . ▁ ▁Em ission ▁caps ▁will ▁be ▁set ▁to ▁account ▁for ▁different ▁air ▁quality ▁needs