US lawWashingtonRegulationsTitle 173 — ECOLOGY, DEPARTMENT OFChapter 173-406 — ACID RAIN REGULATION173-406-900WAC 173-406-900WAC 173-406-900. Nitrogen oxides emission reduction programLast amended: 1994Year: 2026Length: 1 wordsOfficial source (Reserved.)PreviousWAC 173-406-802NextWAC 173-406-950