Volume 2, Number 11
A Gossman Consulting, Inc. Publication
November 1996

Hazardous Waste Combustor Review - Chapter 2

Negative Health and Safety Impacts of the 1996 HWC Regulations


The EPA contends that there is a risk to human health and the environment due to HAP emissions from cement kilns burning waste fuels (FR17360). As a consequence of this, the HWC regulation has been proposed to reduce these risks. There is considerable dispute with regards to the calculation of risk due to emissions. Additionally the EPA has been remiss in that they have made no examination nor considered the added risk to health and the environment due to the implementation of the regulation itself. Such consideration is required by 42 USC Section 7412(d)(2), "...the Administrator, taking into consideration...non-air quality health and environmental impacts...." Such consideration, aside from any legal issue, is also required by common sense and ethics. The following is a listing of the potential negative impacts due to the implementation of the HWC regulation.

Increased Manual Stack Emissions Testing Frequency

The HWC regulation would extensively increase manual stack emission testing frequency over the current BIF standards. The BIF interim status standards require certifi-cation (or recertification) of compliance tests every three years. With the issuance of a Part B Permit however this frequency would drop to every five to ten years depending on the term of the permit. Additionally, BIF allowed the submittal of "data in lieu of a trial burn" i.e. COC Test data. Specifically, 270.66 (a)(2)(iv) states that the Director shall approve a trial burn plan if, (iv) "...the information sought in the trial burn cannot reasonably be developed through other means." Such a provision was obviously included in the regulation because the EPA was aware of the health and environmental risk and cost in requiring unnecessary testing. It is interesting to note, however, that to date no EPA region has accepted data-in-lieu of trial burn, except for identical units at the same site, and no definitive explanation has been presented for such rejection other than guidance from headquarters.

In addition to the increased frequency of the Comprehensive Performance Test (CPT) versus the expected permit requirements, the HWC also requires additional manual stack emissions testing every 1.5 years for parti-culate emission/CEM instrument correlation and confirmatory testing for D/F emissions. This particulate emissions/CEM instrument correlation testing must also be done prior to the CPT and confirmatory test since this PM CEM is used to set operating limits during CPT testing necessitating additional testing sequences.

Consequently, three manual stack emis-sions testing sequences (two for particulate and D/F, and one for CPT) must be performed every three years versus one such sequence under BIF interim status per three years or one under permitted status every five to ten years. Additionally, a Method 29/instrument correlation test for the mercury CEM (and multi-metals CEM once such devices are available) must be conducted every three years as well. It may be possible for this stack emissions sampling to be conducted in conjunction with the PM CEM testing preceding the CPT. However, this may not be logistically possible. For permitted facilities this is a six to nine-fold increase in manual stack emissions testing for a given facility. Consequently the impact of these regulations is a six to nine-fold increase in activities that have risk due to the transporta-tion and execution of this testing by the stack emissions sample collection contractors. This is a major change in risk. Manual stack testing involves transportation of personnel, primarily by automobile, the manhandling of equipment onto sample platforms 20 to 100 feet above grade, long hours in all weather extremes, potential exposure to reagents and stress due to the need to produce high quality service under difficult conditions. Currently, the accident incident rate for stack sampling contractors is estimated by the industry to be 10 per 200,000 man-hours. This rate is about twice the accident rate for chemical manufacturing (5.2 per 200,000 man-hours) and nearly equal to the rate for the construction industry (12 per 200,000 man-hours). In comparison, the accident rate for industries such as crushed stone production and mining are 6.0 to 6.8. (Data on accident rates were taken from the U.S. Bureau of Labor Statistics for 1993 and 1994.) Clearly then, the impact of increased manual stack testing must be considered in any risk assessment involving the implementation of the HWC regulation.

Increased Manual Stack Emission Testing Duration

In addition to the increased testing frequency, there will also be a dramatic increase in test sequence duration. Under BIF, the stack emissions sampling during the COC test sequence could be executed in as few as two 12 to 16 hour days with three days of testing a normal test sequence. However, under HWC the duration of stack emissions sampling has been increased considerably. The particulate CEM correlation testing alone is expected to require at least five days at three runs per day. The requirement that these correlation tests be done at three different grain loadings could easily extend this testing to nine days to allow the facility to establish stable operating conditions for each of the different grain loadings. It may be possible to conduct the CEM instrument /Method 29 correlation test for mercury and SVM/LVM metals during this same period. Again, however, this may not be logistically possible. Also, as currently written, all D/F testing has effectively been extended from two hours and forty minutes per run to six hours per run. Consequently, three days of testing versus one day of testing under BIF would be required for each set of D/F tests.

The CPT will require a minimum of three days of testing. This assumes that there are no problems, that only one operating condition is being tested and that the facility consumes waste fuel in only one location in only one form. Five days would be a more reasonable estimate.

Consequently, the impact of the HWC regulations with respect to frequency and duration of testing is a 21 to 28 fold increase in manual stack sampling time, i.e. from three sampling days under BIF to as many as 84 sampling days under HWC over a period of nine years, thereby subjecting the stack sampling contractor's employees and numerous consultants to risks associated with transportation to test sites and meetings as well as the execution of the sampling, frequently on platforms many meters above grade. As noted above, it is estimated that stack sampling contractors as an industry experience a rate of ten reportable accidents per 200,000 man-hours. This is certainly not an insignificant risk that can be ignored, and it is the result of EPA rule-making without appropriate consideration of real health and safety issues.

Metals Spiking

One of the advantages EPA extolls for the mercury and multi-metals CEM is the reduction in the risk experienced by the testing crew. Specifically, the EPA has stated in the preamble to the HWC regulation Part 5, section II(C)(4)(b) "Finally, the common process of spiking metals during compliance testing to ensure an adequate operating envelope is expensive, potentially dangerous to the testing crew that must handle the toxic metals, and causes higher than normal emission rates during compliance testing. If a MM CEMS were available, there would not be a need to spike metals during compliance testing." Clearly, EPA evidences no equivocation here on two points:

1) That metals spiking is a risk to human health and the environment, and

2) That MM CEMS will eliminate the need for spiking.

On the first there can be no argument, this is a position taken by virtually everyone in the industry. On the second however, the EPA is at best being naive and clearly has not closely examined their own proposal.

The testing requirements for the mercury and MM CEMS require that both the specified standard method, Method 29, and the CEM instruments measure the concentration of the metal being monitored at a level above the lower detection limit. (See Performance Specification 10, Section 7.)

To comply with this provision, any given facility will perform metals spiking for the metals intended to be monitored. This statement can be made based on a simple examination of recent test data. The system removal efficiencies for most of these metals (arsenic, beryllium, and chromium in particular) have very high values commonly 99.99 plus percent. In some cases, even though the facility had spiked metals at BIF COC allowable rates, the emission values were below the lower detection limit for Method 29. With such being the case, EPA's assertion that MM CEMS will eliminate the need to spike metals is not substantiated. If the EPA is concerned with eliminating metals spiking and reducing risks to human health and safety, as they should be, then now is the time to do it! In a communication dated November 9, 1995 from Michael Shapiro to David Gossman it was stated, "Generally, SRE decreases at lower feed rates." What this means is that by conducting COC testing at normal metal feed rates (i.e. without spiking), the SRE values would be lower than with metals spiking. Using these SRE values, the facility could then calculate metal feed rates (by using EPA's conservative models) that are more protective of the environment than by using the SRE values that would be obtained during testing with metals spiking. This eliminates the need for spiking metals and produces a more conservative (i.e. protective of the environment) metals input limit. EPA has a legislated responsibility to act to protect human health and safety, and as such should implement an emergency rulemaking eliminating metal spiking requirements.

The data contained in the technical background documents, Volume IV, does not include any operational data of a mercury or MM CEMS installed at a cement kiln. Without being able to assess such data it is unreason-able to assume that the detection limit of the MM CEM will be as low as Method 29. If this CEM detection limit is one order of magnitude higher than Method 29 then the metal input for a metal intended to be monitored must also be one magnitude higher as well. Additionally, EPA's promotion of technologies to produce even lower particulate emission values will lead to higher system removal efficiencies. This means that even more metals may have to be spiked to achieve stack emission values for the target metals that are higher than the lower detection limit for Method 29 or the CEM. In addition to this, the Performance Specification (PS 10) for the MM CEM also requires a relative accuracy test for one of the metals or iron over three ranges, 0-20, 40-60, and 80-120 percent of the emission limit. Iron is an ingredient in the raw feed of cement kilns at about 2%. Too little or too much iron will affect the product quality of the cement consequently it is highly unlikely that a cement kiln would or even could adjust the iron input rate to produce three levels of iron emissions for CEM/Method 29 comparison. Consequently, in order to produce the three levels, one of the monitored metals must be selected; then to achieve the desired control, it would be spiked. It is therefore likely that the HWC test requirements will actually increase the spiking of metals rather than eliminate such spiking as the EPA has stated in the preamble to HWC. GCI objects to this false and totally unjustified approach to regulations as proposed by EPA, and said so in our comments.

Instrument Calibration and Zeroing and the Absolute Calibration Audit

Part of the daily audit required for any monitoring system includes a zero and span calibration. To accomplish this for the mercury monitor requires that a gas or solution containing mercury be injected into the analyzer. Decidedly this is a small amount of material, the technician who executes this procedure however is in intimate contact with this equipment and is potentially exposed on a routine basis. There are certainly precautions that can be taken to mitigate this potential exposure but this activity should be included in any risk assessment of increased monitoring. The HWC regulation has added a number of such calibration audits. Daily calibration audits for the multi-metals CEM. Quarterly absolute calibration and interference response tests for the mercury analyzer. Daily calibration drift and quarterly absolute calibration audits and interference response tests for the hydrogen chloride and chlorine analyzers. EPA's concern for the "potentially dangerous" metals spiking apparently does not extend to CEMS which operation requires this level of daily, quarterly and annual calibration testing using the same toxic materials. Under BIF the potential expo-sure occurred over a very limited period once every three years (interim status) or five to ten years (permit status) versus daily. Under BIF this potential exposure was limited to a much smaller group of people with considerable elapsed time between episodes. Now, however, under the proposed HWC rules the potential exposure could easily become chronic low level exposure to a much larger group of people.

In addition to the human health risk of the technicians exposure, there is also the risk to human health and environment due to manu-facture, testing and transport of these expensive reagent grade chemicals to each facility. The EPA should also consider the substantial risks involved in merely bringing the CEM instruments on line. EPA's BIF require-ment that CO and THC CEMS be installed was followed by thousands of man-hours by facility and manufacturers technicians debugging their systems. Many of these manufacturer techni-cians spent weeks at a time on the road traveling from one facility to another struggling to make them work. GCI is aware of at least one technician hospitalization due to a fatigue related car accident. The proposed CEM equipment, by comparison to the proposed HWC regulation to the CO/THC CEMS, are much more complex devices, likely adding to these transportation risks as well as risks similar to stack testing during equipment maintenance and installation.

Increased Laboratory Testing

The HWC regulation increases the frequency and number of analyses performed. This, in turn, increases the number of chemists and the exposure of each chemist in performing these analyses. As well as the risk from sample and reagent spills during transportation and the risk from increased waste production, collec-tion, storage, transportation and disposal. The insistence in the HWC rules to use only SW-846 analytical methods also increases waste production (by disallowing such analytical methods as EDXRF or other x-ray techniques for metals analysis in favor of acid digestion and ICAP.) The President has signed a law (OMB Circular A119) requiring consensus methods to be used "...as a means to carry out policy objectives or activities determined by [Federal] agencies." Additionally, the HWC makes little allowance for a statistical approach for reducing this sample frequency as pointed out in a paper presented at the May 1996 Incineration Conference in Savannah, GA by Bill Schofield entitled, EPA's Evolving Guidance on Waste Testing Frequency and Its Impact on Selected BIF Facilities. In this paper, Mr. Schofield points out that the "allowed" statistical approach views analyses with consistent non-detect values as failing to exhibit the required "normal distribution." It would appear that EPA's statistical approach considers concentrations below the detection limit, or consistently finding nothing, as statistically invalid.

The EPA has also failed to make simple observations easily gleaned from the data supplied to them since the implementation of BIF in 1992. One specific example is the insistence on the testing for the metal beryllium. Indeed, beryllium is a highly toxic metal, however it is extremely rare in hazardous waste fuel. It is present in some coals and raw kiln feeds but at very low concentrations. Additionally, unlike mercury which is somewhat more common, beryllium is much less volatile. Consequently, beryllium is not a significant or even a potential hazard at the vast majority of sites regulated under the current BIF rules or the proposed HWC rules. This is important because EPA's insistence virtually precludes the use of an important analytical method for metals, x-ray fluoresence. This method does not require the expensive, time consuming and potentially hazardous digestion of the samples; nor does it create the volume and type of waste typical of matrix digestion (wastes such as nitric, perchloric and hydrofluoric acids). Use of an x-ray fluoresence device as a multi-metal CEM would have similar reduction in operational risk as well. In EPA's pursuit of monitoring a hazard that does not exist, additional hazards are added and created, none of which have been considered in EPA's risk assessment.

Changes in Operation; Added Risk to Human Health and the Environmental

Compliance with the provisions proposed in the HWC, individual facilities will require the investment of capital expense to purchase, fabricate, install and operate monitoring and process equipment. This manufacturing and construction also entails added risk to human health and impacts the environment negatively as well. As noted above, construction is one of the most hazardous of occupations exper-iencing 12 accidents per 200,000 man-hours. Added to this is the impact on the environment of the manufacturing process and the transportation of raw materials and goods to support this manufacturing.

Certain facilities may be able to comply by selected changes in raw materials. Although such changes may not be required under the MACT provisions the facility may find such changes to be more cost effective than the massive process equipment upgrades required by the regulations. There is, however, an environmental impact price for such raw material changes. In virtually every case, if a facility chooses to make such a change it will entail substantial increases due to transpor-tation, e.g. diesel exhaust. Based on a number of studies, heavy duty diesel trucks will emit between 1.3 to 9.5 ng/km of dioxins (TEQ) (Ref. Diesel Truck Emissions, An Unrecognized Source of PCDD/PCDF Exposure in the U.S., Risk Analysis, Volume 13, No. 3, 1993) This referenced paper also documents that the currently estimated dioxin emissions from all such trucks is at least one order of magnitude greater than the estimated dioxin emissions from all hazardous waste facilities. GCI believes that EPA must consider these adverse impacts of the proposed rule, and pointed this out in our comments.

The EPA has promoted fabric filter technologies to control stack particulate emissions. Again, however, the EPA has not considered the overall environmental impact of such a change. The use of fabric filters would prevent wet kilns which currently use ESPs from selectively removing and disposing of high alkali dust. The net effect is that such facilities would waste more dust, i.e. reducing the efficiency of their system as well as increasing non-hazardous waste disposal, lowering production rates and profitability by wasting raw materials. This is in direct conflict with EPA's own policies on waste minimization.

The EPA also promotes carbon injection as a method to reduce mercury and D/F emissions. There is, however, no research as to whether, or how, or if this will work for all cement kilns. One of the formation mechanisms frequently enumerated by the EPA is the formation of D/F molecules on the surface of carbonaceous particles. Clearly, indiscriminate use of carbon injection could, and will, lead to increased D/F emissions (as CCC test results show). To make carbon injection a viable technology would require the installation of additional fabric filter units entailing more construction and more energy to pull the exhaust gases through the filters. To then comply with the CEM/Method 29 correlation test requirements will require even more spiking of the target metals due to the added particulate removal efficiency of this added filter. Additionally, the manufacture of the needed activated carbon also impacts the environment. Particularly at question is the increased HAPs production from increased activated carbon production. A Freedom of Information Act request turned up two USEPA documents (450/3-88-012 and 453/R-92-019), neither of which references any activated carbon manufacturing associated health risks. A followup request reveals that EPA has no data onD/F or other HAP emissions from the production of activated carbon. The production of activated carbon requires the combustion of carbon bearing materials under reducing conditions, thereby driving off hydrogen, oxygen and any other non-carbon atoms. Such a pyrolysis frequently generates a variety of toxic compounds some portion of which are emitted. An even more important question concerns disposal options for the CKD that will be wasted that will be contaminated with activated carbon. It would appear that the agency is proposing to solve a perceived problem by creating a bigger one. This was clearly not part of the congressional intent.


The authorization for the Clean Air Act from which the MACT regulation evolved was very explicit. Section (c)(4) states: "With respect to alkylated lead compounds, polycyclic organic matter, hexachlorobenzene, mercury, polychlorinated biphenyls, 2,3,7,8-tetrachloro-dibenzofurans and 2,3,7,8-tetrachlorodibenzo-p-dioxins, the Administrator shall...list categories and subcategories of sources...are subject to standards under subsection (d)(2) or (d)(4) of this section." This subjects cement kilns and other hazardous waste combustion units to regulation under the Clean Air Act. Section (d)(2) states in part, "...the Administrator, taking into consideration the cost of achieving such emission reduction, and any non-air quality health and environmental impacts and energy requirements...." (emphasis added) The items listed above certainly qualify as "non-air quality health and environmental impacts" and they have not been considered by EPA in the proposed rule. The addition of these items and their consideration should be deemed a requirement under the wording of the Clean Air Act. What about the volumes of these compounds which are necessary to subject a facility to the rules in their category? No such levels have been reached by cement kilns. Consequently, cement kilns should not be subject to the regulation. In addition, EPA's failure to comply with the law in this regard should require EPA to re-propose the regulation in full compliance with the law prior to final promulgation.