US lawUtahRegulationsAgency 13 — Environmental QualityProgram 307 — Air QualityR307-230 — NOx Emission Limits for Natural Gas-Fired Water HeatersR307-230-1R307-230-1R307-230-1. PurposeLast amended: 2025Length: 18 wordsOfficial source Cite as Utah Admin. Code R307-230-1The purpose of Rule R307-230 is to reduce emissions of nitrogen oxides (NOx) from natural gas-fired water heaters.NextR307-230-2