Wisconsin Administrative Code
Department of Natural Resources
NR 400-499 - Environmental Protection - Air Pollution Control
Chapter NR 447 - Control of asbestos emissions
Section NR 447.03 - Asbestos mills

(a) Monitor each potential source of asbestos emissions from any part of the mill facility, including air cleaning devices, process equipment and buildings that house equipment for material processing and handling, at least once each day, during daylight hours, for visible emissions to the outside air during periods of operation. The monitoring shall be by visual observation of at least 15 seconds duration per source of emissions.

(b) Inspect each air cleaning device at least once each week for proper operation and for changes that signal the potential for malfunction, including, to the maximum extent possible without dismantling other than opening the device, the presence of tears, holes and abrasions in filter bags and for dust deposits on the clean side of bags. For air cleaning devices that cannot be inspected on a weekly basis according to this section, submit to the department, and revise as necessary, a written maintenance plan to include, at a minimum, the following:

(c) Maintain records of the results of visible emissions monitoring and air cleaning device inspections and include the following:

(d) Furnish upon request, and make available at the affected facility during normal business hours for inspection by the department, all records required under this section.

(e) Retain a copy of all monitoring and inspection records for at least 2 years.

(f) Submit quarterly a copy of visible emission monitoring records to the department if visible emissions occurred during the report period. Quarterly reports shall be postmarked by the 30th day following the end of the calendar quarter.