SCIENTIFIC REVIEW COMMITTEE MEETING -
January 24, 2002

Pom Pom Ganguli welcomed the SRC members and the audience to the meeting. The topics listed below were discussed during the meeting.

• Minutes of October 25th Meeting
• Responses to Comments from October 25th Meeting
• New and Updated BACT - Part B Listings
• Other Business

Regarding the Gas Turbine listing (IDC Bellingham), a committee member had e-mailed a comment correcting the representation of what he had said at the meeting. The minutes had stated that the Sutter and Los Medanos combined-cycle power plants in California, as well as the Southpoint combined-cycle power plant in Arizona, are meeting 2.5 ppm NOx limits but are operating with ammonia emissions in the 8-12 ppm range, which exceeds vendor guarantees. The committee member wished to change this statement to the following: "The Sutter and Southpoint facilities are meeting their NOx limits but are operating with ammonia emissions in the 8-12 ppm range. These ammonia slip levels are close to, or above, the vendor guarantees". The committee member’s e-mail had also noted that the Los Medanos facility is meeting its NOx/ammonia limits but utilizes turbines with lower NOx levels (9-15 ppm) than those used at the Sutter and Southpoint facilities (nominally 25 ppm).

A committee member noted that the word "member" was missing after the word "committee" near the bottom of page 4.

AQMD agreed to make these changes in the minutes. There were no further comments regarding the minutes of the October 25th meeting. (Gary Rubenstein, Sierra Research; Greg Adams, LA County Sanitation Districts; Howard Lange, AQMD)

 Responses to Comments from the October 25th Meeting

Regarding the new Section I listing for a Tank Degassing System (Envent – A/N 384630), the fact that the permit required the VOC concentration to be measured hourly had been added to the listing, and in the description of the system, the word "mobile" had been replaced with the word "portable".

Regarding the new Section I listing for a Fiber Impregnation System (Cytec-Fiberite – A/N 372603), there were several items. Information about the source of the low-VOC chemicals being used by this facility had been added to the listing. The description of the hood collection efficiency as being 100% had been deleted. Information about the basis for the manufacturer’s claim of 99.999% collection efficiency of the Torit filter had been added. These changes addressed the comments from the October 25^th meeting. It was also noticed that "1-micron" had been mistakenly written in the minutes as "I-micron", and AQMD agreed to correct this error.

Regarding the update of the Section I Boiler listing (Disneyland Resorts – A/N 360389), in which source test data had been added to the listing, AQMD had investigated the unusually high O2 levels reported for Boiler No. 4 and had learned that the cause of the high O2 levels was in-leakage of air upstream of the sampling location. This information had been added to the listing.

Regarding the new Section II listing for a Gas Turbine (IDC Bellingham – ASPIDC [Massachusetts]), a caveat had been added to the listing stating that the concentration limits on NOx, CO, VOC and ammonia are based solely on the emission limits in the Permit to Construct and had not yet been proven by a source test. A similar caveat had been added to the gas turbine listings that had been discussed at the September 6^th meeting (Indigo Energy Facility - A/N 383044, LADWP Valley - A/N 374502, Mountainview Power - A/N 366147, Western Midway Sunset Power Project, Elk Hills Power Project, and Three Mountain Power). AQMD intends to watch the progress of these facilities through completion of their air permitting and update the listings accordingly. (Howard Lange, AQMD)

 New BACT Part B, Section I Listings

AQMD has a certification program for emergency compression ignition engines, which allows engine suppliers to obtain Certified Equipment Permits for specific models that they offer for sale. The Certified Equipment Permit allows purchasers of the engine to obtain a Permit to Operate more quickly and at lower cost than would normally occur. AQMD grants the Certified Equipment Permit on the basis of the engine having received EPA certification that it meets current EPA emission standards for nonroad engines. A summary of EPA nonroad emission standards was distributed at the meeting (copy attached). The Tier 1 standards have been in effect for all engine sizes since January 1, 2001, and are equivalent to existing AQMD BACT for this source category. However, Tier 2 standards, which are significantly more stringent, are now coming into effect, and Certified Equipment Permits are beginning to be issued for engines meeting these stricter standards. The following listings reflect recent Certified Equipment Permits that have been issued to three engine suppliers for a total of nine engine models. (Marty Kay, AQMD)

The nine new Section I listings are as follows:

• Cummins – A/N 390213 (470 BHP), A/N 390214 (395 BHP)
• Caterpillar – A/N 392542 (764 BHP), A/N 392543 (685 BHP), A/N 392544 (610 BHP), A/N 392545 (536 BHP), A/N 392546 (471 BHP)
• Generac – A/N 392676 (267 BHP), 393278 (295 BHP)

A summary of the EPA emission standards to which these engines have been certified or, for engines that have only been certified to Tier 1 emission standards, the apparent actual emissions based on the "engine family data" was distributed at the meeting (copy attached). (EPA certification is done by testing selected engine sizes from an "engine family".) Although these emission levels are not contained in the Certified Equipment Permit or the Permit to Operate, they are the basis for the BACT determination and are included in the BACT listing for each engine.

Discussion: There was a discussion of the EPA certification program and how engine manufacturers are meeting the lower emission limits. AQMD noted that CARB is presently formulating new regulations that will apply to most mobile, portable and stationary compression ignition engines. These regulations will be aimed mainly at reducing particulate emissions and will probably include add-on filters for some classes of new and existing engines. (Bill Dennison, Dennison and Associates; Greg Adams, Los Angeles County Sanitation Districts; Karl Lany, SCEC; Pom Pom Ganguli, AQMD; Marty Kay, AQMD)

An audience member asked how emission standards that are stated in g/bhp-hr can be related to AQMD standards, which are stated in ppm corrected to 3% O2. AQMD responded that emergency engines are not subject to AQMD ppm limits standards. (Jerry Kraim, KEES; Marty Kay, AQMD)

A committee member asked what is the status of research concerning elevated levels of NO2 and ultrafine (sub-0.1 micron) PM being caused by PM filters added to compression ignition engines. AQMD responded that AQMD is participating, together with CARB and DOE, in research being conducted at the University of West Virginia addressing both of these important concerns. (Greg Adams, Los Angeles County Sanitation Districts; Pom Pom Ganguli, AQMD)

An audience member asked whether certified engines are subject to any retesting as a check on possible degradation of emissions performance over time. CARB responded that the EPA nonroad certification program relies solely on testing of unsold specimens but does include some durability testing. AQMD responded that it does not normally test engines that it has certified. (Audience Member; Grant Chin, CARB; Marty Kay, AQMD)

This listing was originally reviewed by the committee in November 1999, at which time it had only a Permit to Construct. Since that time, the equipment was granted its Permit to Operate, in October 2000, and a source test was performed, in July 2001. The source test confirmed that the engine operates below the emission limits in the permit. The new information had been added to the listing. (Howard Lange, AQMD)

AQMD prefaced the new Section II (non-AQMD) listings by explaining that BACT can be based on either a technology meeting the achieved-in-practice criteria or a technology that is included in any approved state implementation plan (SIP). The following new Section II listings are all based on technologies found in a SIP. Recently, Pennsylvania completed a number of RACT determinations on major sources and submitted these to EPA as part of its SIP. EPA adopted these RACT determinations into the Pennsylvania SIP by listing them in the Federal Register. AQMD noted these new Pennsylvania SIP requirements as they appeared in the Federal Register and selected a number of them that are more stringent than existing AQMD BACT. (Marty Kay, AQMD)

This is a water treatment system at a chemical plant, which is used to treat VOC-contaminated wastewater. The method of treatment is to air-strip the VOC from the waste water. The air stream exiting the stripper is required to be directed to a thermal oxidizer with a minimum destruction efficiency of 95%. This system has been in operation since 1992. The destruction efficiency of the oxidizer is tested every five years. The last test was in 1997, and the results of that test confirmed that the oxidizer was achieving a destruction efficiency of at least 95%. (Howard Lange, AQMD)

Discussion: There was some discussion about the high concentration of VOC at the inlet to the oxidizer (approximately 12,500 ppmv). A committee member noted that the stripper treated groundwater in addition to plant wastewater and asked whether the high VOC loading might be from the groundwater. AQMD responded that the groundwater was only a small fraction of the total water being treated and, being from an old coal tar site, was unlikely to contain high levels of VOC. A committee member asked whether acetone, which AQMD does not include in its definition of VOC, was included in the destruction efficiency of the stripper. AQMD responded that it was. (Greg Adams, Los Angeles County Sanitation Districts; Katy Wolf, IRTA; Howard Lange, AQMD)

An audience member asked whether this listing would mean that air stripping would be considered BACT for chemical plant wastewater streams. AQMD responded that the listing would not mean that air stripping would be BACT, it would only mean that venting to a oxidizer with destruction efficiency of at least 95% would be BACT for an air stripper used to treat VOC-contaminated wastewater. (Audience Member; Howard Lange, AQMD)

An audience member asked what was the efficiency of VOC removal from the water by the stripper. AQMD responded that it is seeking this information from the chemical plant and will add it to the listing if it is obtained. (Audience Member; Howard Lange, AQMD)

An audience member commented that the VOC concentration in the inlet stream to the oxidizer exceeded the lower flammability limit of most organic gases and thus would violate a fire code. This individual also commented that the method used to measure the VOC, EPA Method 25, was sensitive to moisture and therefore may not be reliable since the air from the stripper would be heavily laden with moisture. AQMD agreed to look into both of these matters. (Jerry Kraim, KEES; Howard Lange, AQMD; Marty Kay, AQMD; Pom Pom Ganguli, AQMD)

The base equipment in this case is a styrene/butadiene resin manufacturing plant. The plant also produces Acronal, an acrylic latex dispersion. The permit requires that all significant VOC-emitting equipment be vented to a thermal oxider/flare system with minimum destruction efficiency of 99%. This includes essentially all raw material storage, handling and conditioning equipment and the polymerization reactors. The thermal oxidizer is required to be the primary control device, with the flare being a backup control device. The 99% destruction efficiency of the thermal oxidizer has been confirmed by source testing. Recent tests had demonstrated that the oxidizer could achieve 99% destruction efficiency at operating temperatures as low as 1200F. (Howard Lange, AQMD; Marty Kay, AQMD)

Discussion: Audience members asked whether this listing would mean that this control technology would be considered BACT for all resin manufacturing. AQMD responded that it may be, on a case-by-case basis, if process streams were similar to those being treated in this case. A committee member stated that there were other examples of similar processes being controlled with oxidizers meeting 99% destruction efficiency. An audience member asked whether an operating temperature as low as 1200F would be acceptable to AQMD. AQMD responded that the operating temperature would not be an issue so long as the oxidizer met 99% destruction efficiency. (Rita Loof, RadTech; other Audience Member; Marty Kay, AQMD; Anoosheh Mostafaei, Ship and Shore Environmental; Pom Pom Ganguli, AQMD)

A committee member requested that AQMD obtain information about secondary emissions from the oxidizers mentioned in this listing and in the previous listing (Sunoco Chemical), including especially NOx and CO and add this information to the listings. AQMD agreed to attempt to do so. (Greg Adams, Los Angeles County Sanitation Districts; Howard Lange, AQMD)

AQMD read a comment that had been e-mailed by a committee member who could not attend the meeting. This committee member requested that the VOC concentration in the gas entering the oxidizer be included in all listings that involve oxidizers. AQMD agreed to attempt to do so. (Gary Rubenstein, Sierra Research; Howard Lange, AQMD)

An audience member asked what method was used to measure VOC in the source test. AQMD stated that it had received a copy of the test report and would add this information to the listing. (Jerry Kraim, KEES; Howard Lange, AQMD)

A committee member asked how the process equipment was vented to the oxidizer. AQMD responded that this is evidently a confined process, based on the fact that there is a leak detection and repair program required in the permit, and process equipment is therefore presumably venting to the oxidizer by internal pressure, but venting may be assisted by a suction blower. AQMD agreed to look into this and add any additional information to the listing. A committee member offered to provide AQMD with a diagram of a typical chemical plant venting arrangement used with a thermal oxidizer. (Hal Taback, HTC; Pom Pom Ganguli, AQMD; Howard Lange, AQMD; Anoosheh Mostafaei)

This is a grease manufacturing plant in which grease is prepared in a number of kettles. Each kettle is a batch operation. The permit requires that each kettle be fully enclosed and vented to a thermal oxidizer with minimum operating temperature of 1500F, minimum residence time of 0.5 sec and minimum destruction efficiency of 98.9%. The oxidizer, which was supplied by Smith Engineering, is a three-chamber pebble-bed type regenerative oxidizer. Smith (now out of business) normally guaranteed this type of oxidizer to meet 99% destruction efficiency (but not less than 10 ppm at the outlet). The oxidizer was installed in 1991, and the most recent source test was in 1997. Unfortunately, the source test procedure did not follow the normal practice of conducting a short test at a normal inlet VOC loading. The owner chose instead to conduct a longer-term test in which the destruction efficiency was monitored for a full week. The only available information from this test is that the average destruction efficiency was 96.5%. A copy of the test report could not be found. The local air district believes that the 96.5% one-week average is not representative of the destruction efficiency of the oxidizer had it been tested following the normal test procedure. Since the kettles were operated batchwise, the one-week period probably included times when the inlet VOC loading was low, and the average destruction efficiency was therefore probably biased low relative to what would have been measured in a normal test. AQMD is attempting to obtain more information on the test procedure and results of the one-week test.

Discussion: A committee member asked what were the feedstocks to this process. AQMD responded that grease manufacturing basically uses oils mixed with soaps and water. (Greg Adams, Los Angeles County Sanitation Districts; Howard Lange, AQMD)

AQMD read a comment that had been e-mailed by a committee member who could not be present. This committee member felt that this listing may not be justified in that the source test result does not confirm that the oxidizer can meet its required destruction efficiency. Another committee member asked whether AQMD would go ahead with this listing or would hold off. AQMD responded that it would attempt to obtain more information and then make a final decision. (Gary Rubenstein, Sierra Research; Bill Dennison, Dennison and Associates; Marty Kay, AQMD)

A committee member noted that this listing contained information about the inlet flow rate to the oxidizer whereas the previous listing (BASF) did not. AQMD agreed to attempt to obtain similar information for the BASF listing and add it to that listing. (Hal Taback, HTC; Howard Lange, AQMD)

This drum reclamation furnace is basically a refractory-lined box with multiple burners. Steel drums (55-gal) pass through the furnace inverted, on a chain conveyor. The furnace has an integral afterburner. The permit for this furnace requires that it be vented to an afterburner with minimum operating temperature of 1600F and minimum residence time of 0.5 sec. These requirements exceed existing AQMD BACT for this source category, which is an afterburner with 1400F minimum temperature and 0.3 sec minimum residence time. The destruction efficiency of the afterburner was tested in 1996 and was found to be greater than 99.9%.

Discussion: An audience member asked whether the 99.9% destruction efficiency would be considered BACT. AQMD responded that it would be up to the permit engineer, but it is unlikely that 99.9% destruction efficiency would be required. (Audience member; Howard Lange, AQMD; Marty Kay, AQMD)

Committee members requested that information about the inlet concentration of VOC to the oxidizer, secondary pollutants, fuel, and major VOC constituents be obtained and added to this and other thermal oxidizer listings. AQMD agreed to attempt to obtain such information and add it to the listings. A committee member pointed out that the air districts in Pennsylvania may not have required that the oxidizers be optimized for NOx and may not have required that they be tested for NOx. AQMD added that in this context it would be helpful to know whether the involved air districts were in attainment for NOx and stated that it would find out. (Greg Adams, Los Angeles County Sanitation Districts; Bill Dennison, Dennison and Associates; Karl Lany, SCEC; Anoosheh Mostafaei, Ship and Shore Environmental; Pom Pom Gamguli, AQMD)

This facility manufactures steel office furniture. Part of the manufacturing process is a painting operation, in which parts are suspended from hooks and hand-sprayed. Baffles are used to catch overspray and direct it downward to collection drains. The burnoff furnace is used to burn the paint off the hooks and baffles as well as floor grating from the painting area. The permit requires that the furnace have a minimum operating temperature of 1400F and a minimum residence time of 0.5 sec. These requirements exceed existing AQMD BACT for this source category, which is an afterburner with 1400F minimum temperature and 0.3 sec minimum residence time.

Discussion: An audience member asked whether there was any information on the destruction efficiency, for example a source test. AQMD responded that there was no minimum destruction efficiency in the permit and a source test had not been required. AQMD stated that it would report back to the committee as to whether it normally requires a minimum destruction efficiency for a burnoff furnace. (Jerry Kraim, KEES; Howard Lange, AQMD)

This is a steel rolling mill with a permit requirement that low-VOC lubricants are to be used in the rolling operations. Maximum allowed VOC contents in the lubricants are 2% for cold rolling and 4% for hot strip rolling. These lubricants, which are commonly referred to as "rolling oils" are oil-water emulsions, which are sprayed on the workpiece as it is rolled. Rolling oil that is not vaporized is collected and returned to the sprayers. Based on discussions with one rolling oil manufacturer, the 2% and 4% VOC limits do not seem very stringent, and it should not be difficult for mills to comply with them. AQMD is attempting to obtain more information on the ranges of VOC that occur in the undiluted oils used to make up the rolling oils and the ranges of percent oil in water that are used in hot and cold steel rolling.

A list of meeting dates in 2002 was distributed at the meeting (copy attached). AQMD announced that the next meeting would be held March 28, 2002.

There was no further discussion, and the meeting was closed.

Attachments: U.S. EPA Nonroad Emission Regulations