MOJAQMD RULE 1307 EMISSION OFFSETS

LAST REVISED 10/27/93

(Adopted: July 21, 1980) (Amended: 10/27/93)

RULE 1307

EMISSION OFFSETS

(A) Offset Thresholds

Offsets are actual emission reductions (AERs) sufficient to

mitigate emission increases of affected air pollutants from

a new or modified major facility. An affected facility

subject to the offset requirements of this rule shall

provide offsets for each facility on an annual basis.

Offsets shall be required for emissions increases from

affected facilities which emit, or have the potential to

emit, any affected air pollutant for which the District has

been designated non-attainment, equal to or exceeding the

following thresholds:

Pollutant Offset Threshold

NOx 25 tons/year

SOx 25 tons/year

ROC 25 tons/year

PM10 15 tons/year

CO 100 tons/year

H2S 10 tons/ year

Pb 0.6 tons/year

Offsets shall not be required for an existing facility when

the aggregated emissions change over any consecutive five

year period is less than 25 tons for any affected air

pollutant and the proposed potential to emit does not

represent an increase from the historic potential emissions.

(B) Determination of Offset Requirements

(1) New Major Facility

Offsets shall be required for emissions increases from

a new facility with potential to emit, calculated in

accordance with Rule 1306(D), affected pollutants or

their precursors equal to or exceeding the threshold

specified above. The amount of offsets required shall

be the total amount of emissions, on a pollutant

category specific basis, pursuant to Rule 1306(D).

(2) Existing Facility

Offsets shall be required for emissions increases from

a modified facility under the following conditions:

Non-major Facility

(a) An existing facility which has a potential to

emit, pursuant to 1306(C), less than the

thresholds specified above for affected air

pollutants or their precursors, shall offset that

portion of the facility's potential to emit,

pursuant to 1306(D), which exceeds the threshold

for new or modified permit units.

Major Facility

(b) A facility's potential to emit shall be

calculated in accordance with Rule 1306(C).

After the potential to emit for an affected

facility has exceeded the facility's historic

potential emssions as of October 27, 1993, and

the applicant has provided actual emissions

reductions to offset emission increases in excess

of these levels, all future increases from new or

modified permit units shall be offset; and

(c) An existing affected facility shall offset any

increases in potential to emit, calculated

pursuant to Rule 1306(D), resulting from the

permitting of any new or modified permit unit.

(3) Seasonal Sources

(a) New or modified seasonal facilities shall provide

offsets on a quarterly basis.

(b) Seasonal emissions used for offsets shall

generally occur during the same consecutive

monthly period as the new or modified facility

operates.

(C) Location of Offsets and Offset Ratios

An affected facility shall provide offsets for the net

emissions increase on a pollutant category specific basis,

calculated in accordance with Rule 1306(D) and multiplied by

the appropriate offset ratio listed in the following table:

Table of Offset Ratios

POLLUTANT OFFSET RATIO

Reactive Organic Compound (ROC) 1.0 TO 1.0*

1.3 TO 1.0**

Oxides of nitrogen (NOx) 1.0 to 1.0*

1.3 to 1.0**

Oxides of sulfur (SOx) 1.0 to 1.0

PM10 1.0 to 1.0

Carbon monoxide (CO) 1.0 to 1.0

Hydrogen sulfide (H2S) 1.0 to 1.0

Lead (Pb) 1.0 to 1.0

* When located in a Federal Ozone Attainment Area

** When located in a Federal Ozone Non-attainment Area

the offsets must be obtained from facilities within

the same Non-attainment Area

(D) Modeling For Offset Purposes

(a) Offset Requirements for Increases in Attainment

Pollutants

Offsets shall not be required for increases in

attainment pollutants if the applicant demonstrates to

the satisfaction of the APCO, through an impact

analysis, that the ambient air quality standards are

not violated in the areas to be affected, and such

emissions will not cause or contribute to a violation

of ambient air quality standards.