MARIPOSA COUNTY AIR POLLUTION CONTROL DISTRICT
RULE 409 - EXEMPTIONS TO RULE 408
The Air Pollution Control Officer may exempt from the provisions of Rule 408 any of the following facilities or
modifications, or portions thereof, with respect to attainment pollutants:
- Portable facilities being relocated which have received Permits to Operate after January 1, 1981, and temporary
sources of emissions if:
- Emissions from the facility would not exceed emissions limitations provided in these Rules and Regulations
and would not cause or contribute to a violation of a national ambient air quality standard; and
- Such operation would impact no Class I area and no area where an applicable increment is known to be violated;
- Notice is given to the Air Pollution Control Officer at least 90 days prior to a relocation identifying the
proposed new location and the probable duration of operation at such location.
- Modification of a source for the sole purpose of converting from the use of petroleum products, natural gas,
or both, by reason of a natural gas curtailment plan in effect pursuant to the Federal Power Act or the Federal
Energy Supply, and Environmental Coordination Act of 1974 (or any superseding legislation). An exemption for such
a modification shall not apply for more than five (5) years after the effective day of such plan.
- Any modification which causes no net increase in the quantity of emissions from a facility, or any facility
which causes no net increase in the quantity of emission within a District zone. Emission offset eligibility shall
be determined through the provisions of Rule 411. No exemption shall be allowed if the facility or modification
would impact a nonattainment area or an attainment pollutant increment violation area for such pollutant
- Sources of fugitive dust.
- Any facility or modification which is not a major facility or major modification except any which would have
the potential to emit an increase of emissions in excess of
- 5.O tons per year of lead;
- 0.02 tons per year of asbestos;
- 0.001 tons per year of beryllium;
- 0.3 tons per year of mercury;
- 3.0 tons per year of vinyl chloride;
- 3.0 tons per year of fluorides;
- 7.0 tons per year of sulfuric acid;
- 10.0 tons per year of hydrogen sulfide;
- 10.0 tons per year of total reduced sulfur.
- Any source of carbon monoxide which the Air Pollution Control Officer determines would not cause a violation
of any national ambient air quality standard for such pollutant at the point of maximum ground level impact.