Except as specified in Env-A 2002.04, below, the owner or operator shall not cause or allow average opacity from fuel burning devices installed on or before May 13, 1970 in excess of 40% for any continuous 6-minute period.
N.H. Admin. Code § Env-A 2002.01
#6505-B, eff 5-1-97 (formerly Env-A 1202); ss and moved by #8331, eff 4-23-05 (from Env-A 2003.01); ss by #10416, eff 9-24-13