UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION IX
 

215 Fremont Street
 

San Francisco, Ca. 94105
 

February 16, 1989 

MEMORANDUM 

SUBJECT:	 Rule Effectiveness 

FROM:	 

Air 

David 

Programs 

L. Calkins, 

Branch, 

chief 

Region 

IX (7) ~~

TO:	 G. T. Helms, Chief 

03/CO Branch, AQMD (MD-15) 

We have reviewed the proposed alternative program of rule 

effectiveness evaluation that was prepared by your staff and sent 

to us by memo on January 11, 1989. We have the following comments. 

Rule Effectiveness - Comments on the Concept in General 

The California Air Resources Board and Air Pollution Control 

Districts in California place a considerable amount of resources 

and attention on the preparation of a reliable emission inventory 

for all air contaminants, criteria and noncriteria. The 

statewide stationary source emission inventory (for VOC sources 

greater that 25 tpy and other criteria pollutants) is updated 

every four years. In most Districts, the inventory is updated 

more frequently and there is a great deal of confidence that the 

minor « 25 tpy) sources are also reasonably depicted. For most 

categories, a compliance factor is built into the emission calculation. Therefore, the State of California believes that their 

emission inventory is a reasonably accurate representation of the 

anthropogenic emissions being released in the state. 

When the districts put together the inventory, there is an 

opportunity for the staff engineers to evaluate the reasonableness of the controls in place in a certain emission category. 

For example, when Stage II Vapor Recovery rules were adopted, the 

early year inventories reflected poor compliance. The percent 

compliance has improved over the years, but the inventory still 

does not reflect 100% compliance. In other words, some good engineering jUdgment and practical enforcement experience is used 

in the preparation of the inventory which takes into account rule 

effectiveness. As the inventory is updated in subsequent years, 

these factors are further refined to best represent real emission 

conditions in the air basin. 
/
 

Applying the arbitrary 80% rule effectiveness factor to an 

abatement device presently using abatement efficiency of 95%, 

80%, or 70% will result in raising emissions from the source by 

380%, 80%, and 46.6%, respectively. These values were obtained 

by comparing the results of the equation with a rule effecti~eness factor and without. The equation is included .in the 

guidance documents. 

Controlled uncontrolled [1 - (control equip eff) X (rule eff)] 

emissions emissions 

For a source with 95% control equipment efficiency, without a 

rule effectiveness factor, the multiplier would be .05. For the 

same source with an 80% rule effectiveness factor, the multiplier 

would be 0.24. This will result in a 380% change in controlled 

emissions from sources which have control equipment with 95% efficiency as compared to the inventory figures which the Districts 

believe is the best estimation of actual emissions. 

California places considerable emphasis on maintaining the 

inventory because they are genuinely concerned that the planning 

efforts which are based on these numbers will achieve the results 

they need to attain the NAAQS. In addition, most of the technical work performed in California is continually challenged by 

representatives of industry and environmental groups. 

In California, the state and some of the districts, perform 

fairly rigorous audits of identified sources in the inventory on 

a routine basis. When discrepancies are found, an adjustment is 

made to the emission figures in the inventory. Some of the 

larger districts have developed their own emissions inventory 

audit programs which combine permitting, compliance and enforcement program information. All of the districts in California 

have recently been given authority (under the Sher Bill) to 

charge emission fees. This program will reduce overreporting of 

emissions, while the audit program and compliance inspection will 

reduce underreporting. It has been suggested that the development 

of an emission inventory audit program would be a better utilization of emission inventory personnel than filling out 10 source 

file questionnaires for each source category. 

While we all agree that rule effectiveness considerations 

need to be made in emission inventory programs, we disagree on 

where th7 fa~tor is to be.applied to best improve the inventory. 

The appllcatl0n of an arbltrary rule effectiveness factor, 

w~ether derived from questionnaires or a straight 80%, will 

hlnder rather than improve emission inventory development in the 

state of California. Therefore, while California has committed 

to improve their inventory by seasonally adjusting and listing 

sources between 10 & 25 tpy, they will probably not apply a rule 
effectiveness factor to the final calculation of emissions from 

each source when the inventory is submitted to EPA for the Post 

_ ~98J Ozone/CO Plans. 

We understand that not all air pollution control programs 

throughout the country have the resources available to place this 

much emphasis on inventory' programs, and that the use of the 

questionnaires may be a viable optionofor them. But for agencies 

which do have this luxury, we request that leeway be given to address the issue with an alternative program. 

Rule Effectiveness - Comments on Use of the Point & Area Questionnaires ' 

The following are comments on the draft questionnaires as 

provided by your office in a memo dated January 11, 1989. 

It makes some sense to develop three (or more) point sources 

questionnaires so that weighting of factors can be more equitable 

and specific to types of operation. We suggest at least the following three: solvent use operations, petroleum operations, and 

fuel combustion operations. 

The use of the questionnaires, as opposed to the across the 

board 80%, is a very resource intensive option for a state or local agency to choose which may not result in very much bottom 

line difference of the baseline emission inventory. Therefore, 

there is very little incentive to use the questionnaires unless 

all their rules are written and enforced perfectly to make up the 

20%. For area sources, most of the data is based on estimated 

activity data and number of sources. Correcting this with an arbitrary 80% non-compliance rate will not improve the estimates. 

What prevents some states and local agencies from raising 

all their numbers up by 20% only to apply the factor? Any emission inventory does NOT reflect accurate emissions; at its best 

it is a reasonable representation of emissions of an air basin. 

The questionnaires do not allow a rule to be more than 100% 

effective. What about the situation where you have a Continuous 

Emission Monitor (CEM) in place at source and the data shows that 

the emissions have always been under the inventory level? or 

where a source is permitted at a specific level based upon previous economic operating conditions and now the source has reduced 

operation? 

Use of the point sources questionnaire make it very difficult to get 100%, even if the real emissions accurately 

reported in the inventory. For example, if a source does not 

keep good records, but is in compliance because of compliant 
i 

,	 coatings (not irreversible) they would have some points deducted. 

It is possible for a source to be in violation with a rule and 

yet emit emissions lower than the uncontrolled emissions level. 

Therefore, the application of a rules effectiveness factor would 

make the inventory an inaccurate reflection of emissions .from 

that source. 

If you have any questions, please contact Kathi Moore at FTS 

454-0567.