Section 426 - HYDROCARBONS426.1 Hydrocarbons (less methane) measured at an ambient air monitoring station during the hours and months specified shall not exceed an average concentration of 160 micrograms per cubic meter (0.24 ppm) for any three (3) consecutive hours more than once during the entire period: 6:00 am to 9:00 am from April 1 through October 31.426.2 Sampling and analysis for hydrocarbons shall be as outlined in Section 180. Wash. Admin. Code Northwest Clean Air Agency, 400, 426