San Diego

San Diego Air Pollution Control District (SDAPCD)

California’s ambient air quality standards classified San Diego County as nonattainment for 1-hour and 8-hour ozone, PM2.5, and PM10. Based on EPA standards, the county was designated moderate nonattainment for the 2008 8-hour ozone standard.

ERCs are available for six different pollutants:

Pollutant Significant Emission Rates
Nitrogen oxides (NOx) >40 tons/year
Volatile organic compounds (VOc) >13.7 tons/year
Sulfur oxides (SOx) >40 tons/year
Carbon monoxide (CO) >100 tons/year
PM10 >15 tons/year
PM2.5 >10 tons/year

To satisfy offset requirements, new or modified major facilities in nonattainment areas must obtain ERCs to satisfy the offset ratio requirements for proposed emission increases.  The offset ratio for nonattainment area for ozone precursors such as NOx and VOC is 1.2. That means if 100 tpy of NOx or VOCs are emitted from a proposed new or modified major facility in the nonattainment area for ozone, the facility must obtain 120 tpy of ERCs to offset the increase in NOx or VOC emissions. For any other EPA designated nonattainment air contaminant or its precursor, emissions increase shall be offset at a ratio of 1.0.

SAPCD also allows the use of interpollutant emission offsets at the ratios specified below to satisfy the NOx and VOC offset requirements.

Emissions Increase Emissions Decrease Interpollutant Ratio
Nitrogen oxides (NOx) NOx
Volatile organic compounds (VOC) NOx