MACT Implications of Alternative Raw Materials
Presented at the April 2003 A&WMA Hazardous Waste Combustors Specialty Conference
Gossman Consulting, Inc.
Use of alternative raw materials is not only widespread throughout the cement manufacturing industry, both hazardous waste fuel users and non-haz cement plants, but when does raw material substitution trigger another performance test? The 12-6-02 federal register pointed out that § 63.1349(e) require a new performance test if a plant anticipates making a significant operational change that may adversely affect compliance with an applicable D/F or PM emission limitation. How does a facility determine when they are “initiating any significant change in the feed or fuel from that used in the previous performance test.”1 Hazardous waste fuel burners have been concerned about triggering additional testing for years. This paper examines raw material substitution and the potential effect on additional performance testing.
Waste fuel burners have been concerned about what constitutes a significant change in operations, particularly with regard to fuels and raw material substitutes, since the boiler and industrial furnace regulation kicked into effect in 1992.2 As anyone who deals with regulatory compliance knows, particularly when it is hazardous waste related, the intention of a regulation does not always have much similarity to the enforcement of that regulation. One has only to look as far as the Bevill amendment and all the gnarling and gnashing of teeth that has taken place over the past twenty years for a good example.3 A more recent example would be the legislative history to the 1990 Clean Air Act amendments that discussed emissions caused by raw materials not being of regulatory concern and the resulting compliance testing requirements to see how the relationship can be a total disconnect.4,5 Probably the biggest concern has to do with raw material substitution since cement plants are always looking at ways to cut production costs. What better way to cut production costs than to reuse waste materials that are destined for disposal of some sort anyway. It is a win-win situation.
Frankly, this is a question that may never have one definitive answer. Since MACT has muscled its way onto the regulatory scene, the states will take an increasingly larger role in the regulation of cement plants. This is not necessarily a bad thing but it will likely insure that there are up to 50 definitions of what a significant operational change may be when it comes to raw material substitution. In the case of a cement plant in Maryland, testing associated with each raw material substitution is written right into the permit. While that may make things cut and dry, testing every time a raw material substitution is desired is certainly not necessary. The bottom line is that regulators are concerned about a change in emissions.
The great thing about cement manufacturing and waste disposal is that it is theoretically possible to substitute 100% waste materials for the normal raw materials and kiln fuel required to make good clinker. A raw material substitute only works when it balances out in the cement chemistry necessary to make good clinker. Consequently, demonstration that a raw material substitute candidate will be similar in composition and essentially an even exchange in the emission department makes a defensible case against a “significant operational change” which would trigger additional stack testing. Many cement manufacturing locations are already doing this and have successfully changed raw material substitutes several times between required compliance tests without triggering additional testing. Again, it will depend upon the regulating authority but a defensible case can be made.
In addition to various metals, applicable either under specific regulation or applied by various states, there is of course the dioxin/furans concern. A general parameter, which does not yet get much attention from non-haz cement plants, is organics, which in some cases are pre-cursors for D/F emissions. In addition, there is the potential presence of some level of dioxins/furans in the alternate raw materials themselves. And as many waste fuel burners know, those who have looked into dioxin/furan emissions in any depth, there is also the possibility of what some call naturally occurring D/F in the typical cement clinker manufacturing raw materials. Again, a defensible position is the key.
Many hazardous waste burning cement plants have learned valuable lessons since the boiler and industrial furnace regulations came into effect. There was a former hazardous waste burning California cement plant that exceeded their lead input level only to find that they had hit a high lead vein in their quarry. There were several non-hazardous waste burning kilns that just went through PC MACT6 compliance testing who were surprised to learn that not only were they not area sources but that they were actually exceeding the regulatory emission limits for all sources. Testing raw materials on a regular basis is the answer to heading off potential problems and demonstrating to regulators that additional testing is not necessary, as there was no “significant change in the feed or fuel from that used in the previous performance test.” An effective raw material/raw material substitute monitoring program can be implemented for substantially less than having to perform another stack test for several thousand dollars. Compliance tests also take up quite a bit of plant time.
A Region IV USEPA Administrator once said at a conference in Knoxville, Tennessee that a facility must document, document, document! While this admonition referred to proof that you were complying with the regulations, it can be applied as well to raw material substitution. The non-haz cement plants are on the front end of a learning curve that the hazardous waste burning cement plants were on ten years ago. The lesson boils down to knowing what is going into your cement manufacturing process in order to be able to make a case for what is going out your stack. Emission limits and applicable operating limits are established during compliance testing. This is not an inexpensive venture. There is no reason to repeat compliance testing unless you absolutely have to do so. Cement plants use their knowledge of cement chemistry and individual kiln operational parameters to manufacture good clinker. Regular monitoring of raw materials is not only a good idea from a cement chemistry standpoint but a few additional analytical parameters can put you in a defensible position to avoid unnecessary costly compliance testing.
1-Federal Register: December 6, 2002 (Volume 67, Number 235); page 72582
2-Federal Register: February 21, 1991 (Volume 56, Number 35); 7134-7420
3-Federal Register: November 8, 2002 (Volume 67, Number 217)
4-Federal Register: September 30, 1999 (Volume 64, Number 189); page 42882, fn 137
5-Federal Register: June 14, 1999 (Volume 64, Number 113); page 31917, fn 2
6-Federal Register: June 14, 1999 (Volume 64, Number 113); 31897-31962