R307-312-4. Visible Emissions

(1) Visible emissions from sources subject to R307-312 shall not exceed the opacity limits as specified in Table 1.

TABLE 1

CATEGORY OPACITY LIMIT

Crushers 12%

Screens 7%

Conveyor transfer points 7%

Concrete batch plants 7%

(2) Opacity Observation.

(a) Opacity observations of emissions shall be conducted according to 40 CFR 60, Appendix A, Method 9.

(b) The duration of the Method 9 observations shall be 30 minutes (five six-minute averages).

(c) Compliance shall be based on the average of the five six-minute averages. The duration of Method 9 may be reduced to 6 minutes (one six-minute average) if the first six-minute average is below the limit specified in Table 1.