Rule 3.22 Internal Combustion Engines 

Public Workshop April 16th, 2009 

Public Comments 

Q. Where can we get a copy of the presentation? 

A. Tim Mitro (Mitro), Air Quality Engineer for the District, noted that the handouts were available 

at the meeting and said he would also post them on-line. 

Q. Regarding the replacement of the non-compliant engines, with some involved in Natural Gas 

well sites, the engine is an integral part of the unit. Therefore, the costs for replacing some engines 

would be high. 

A. Mitro explained that the emission limits in the draft rule are consistent with surrounding air 

districts as well as statewide. 

Q. I’ve heard of cost being a factor in determining what is feasible for compliance with other 

district’s Stationary I.C. Engine Rules. Will this be a factor in this district? 

A. Mitro and David A. Valler Jr. (Valler), Air Pollution Control Officer, discussed the differences 

between Best Available Control Technology (BACT) for new installations and this rule for NOx reductions 

on a day-to-day basis. We evaluated the costs and the “feasible” emissions reductions expected for the

daily operations. 

Q. If we make the investment to bring the engines into compliance with the emission limits 

proposed in this Rule, are the emission limits going to change in a couple years and require additional 

costs? 

A. Valler explained that the District does not intend to modify this rule, once adopted, at this time.

Mitro explained that the District bases emission limits on Best Available Control Technology, which 

agencies re-evaluate continually as technology advances. 

Q. What is the possibility of issuing a horsepower (hp) restrictive permit? For example, if I have an

engine that usually runs at 80 hp to perform regular work load, but it is rated a 200 hp engine, could I 

have a permit that states that the engine will only operate at 80 hp? 
A. Karla Sanders (Sanders), Air Quality Compliance Supervisor, responded that a horsepower 

restrictive permit is acceptable if the restrictions were certified by the manufacturer and verifiable in the 

field. Mitro responded that companies should do the source test at normal operating load. Therefore, 

they should test the engine at 80 hp if the normal operating load is 80 hp. Sanders questioned the 

reason for placing hp restrictions on the permit because the rule does not have different limits for 

different hp engines. The only reason to restrict hp is if you wanted to exempt the engine from the rule. 

For example, a 60-hp engine that has hp restrictions on the permit allowing 45-hp for normal operations 

would be exempt from the limits in the rule. 

Q. Regarding the hp restrictive permits, have you heard of adding a governor to the engine that 

restricts the hp to a maximum level? There are other technologies, such as one used in Santa Barbara,

that inserts a plate into the engine that limits hp. 

A. The District is not familiar with this technology, but is willing to look at examples provided. Staff 

will follow up on this comment. 

Q. Is submitting the Authority to Construct in compliance with Rule 3.22 like starting over on a new 

permit? 

A. Mitro responded that the ATC is not like starting a new permit, it is a modification of an existing

permit. The ATC is to document the plan intended for the engine to meet the deadline. 

Q. Would the District have to apply BACT as part of the ATC modification? 

A. Mitro responded that BACT would not be required since the engine is already installed and 

there is no increase in emissions. 

Q. Will the District accept comments on this draft Rule by email? 

A. Mitro responded that the District would accept comments by regular mail or email before May 

18, 2009. 

Q. The cost to comply with the source test requirement of this Rule will be about $200,000.00 

because I have 67 engines over 50 hp in North Sutter County as of 2008. Hiring a company to conduct 

the source test, paying District staff to witness the source test, at a max of three engines per day, plus 

the shut down and start up of the engines will be a significant financial burden. Can we just use the NOx 

analyzer to show compliance rather than the source test every five years? 
A. Valler stated that the NOx analyzer is not a legal standard, nor EPA approved. Mitro stated that 

while Districts to the North use the NOx analyzer only, the Districts to the South require source testing, 

some every year rather than every 5 years that the District is proposing. The source test is required to 

verify that the engine is still meeting the standard after years of use. Mitro also stated that there are 

other options to show initial compliance, such as submitting the results of a source test performed 

within the past three years in another District, or if new, manufacturer supplied emissions information, 

at the discretion of the APCO. 

Q. Would there be a possibility that the source test requirement could be spread across the five 

years for facilities that have a large number of engines? 

A. The District will consider this option. 

Q. Would there be a possibility for a sliding scale for multiple engine facilities? 

A. The District will consider this comment. 

Q. The District should consider only source testing larger engines, like over 250 hp, and only 

require NOx analyzer for 50-249 hp engines. 

A. The District will take this comment under consideration. 

Q. What does “most cost-effective” measures mean on the presentation? 

A. Mitro explained that cost-effective considers the amount of pollutants reduced per dollar spent 

on controls. The District considers what source types could reduce the most emissions with the least 

amount of money. Engine emission reductions in the draft rule are the most cost effective reductions for 

all the source types in the District. 

Q. Many of the engine sites cannot use electric motors since the infrastructure is not available. Is 

there a lesser compliance option for engines that cannot be converted to electric motors? 

A. Mitro explained that many sites would not be able to use electric power, but there is no lesser 

compliance option for these engines. The District encourages electric conversion for facilities that have 

existing electric power as this option results in the most emission reductions. Valler commented that the 

availability of electricity increases as the area grows. 
Q. Since a source test is required to measure VOC, and rich burn engines have a much lower level 

of VOC than NOx, can we remove the requirement for source testing and just use the NOx analyzer to 

demonstrate compliance? 

A. The District is not considering removing the requirement for source testing, nor removing the 

emission limits for VOC, from the draft Rule. 

Q. Is a lean burn Ajax engine that meets the 150-ppmv limit for NOx permissive to operate? 

A. Mitro stated that it was.