1. (a) Neither visible fugitive emissions nor visible stack emissions from a cement, ready mix concrete, or cement block source shall exceed an average of 20 percent opacity for any continuous 6-minute period.
2. (b) Opacity shall be determined in accordance with Env-A 807.

Source. #6428-B, eff 1-18-97 (formerly Env-A 1210); ss by #8218, eff 11-24-04; ss by #9793, eff 10-1-10; ss by #12693, eff 12-22-18