MACT Task Force

MEMORANDUM

October 22, 2014

To: Jeff Telander, US EPA

From: Terry Schimmel and Susan Miller, Brick Industry Association

RE: Potential Mercury Emissions from Clay Brick Kilns

The purpose of this memorandum is to present available information on potential mercury emissions 

from clay brick manufacturing. Since there has been no interaction with the EPA program personnel in 

the last year or so regarding potential mercury emission limits, this memorandum is based on the 

limited information about potential regulations provided during the small business panel meetings held 

in mid-2013.

While our industry in total would emit far less than one ton of mercury if we were ever to return to near 

full operating capacity at all of our facilities, it is our understanding that the EPA continues to consider 

the potential of setting a numerical limit. Since mercury has never been regulated in our industry 

previously, the only stack test data we have is limited to EPA’s section 114 required testing in 2010. In 

addition, all of these tests were conducted on dry injection fabric filter (DIFF) systems. Therefore, the 

data are not adequate to characterize mercury emissions from this industry and set a numeric standard 

that would in any way be representative of the better performing sources in the source category. What 

we do know, however, is that a numeric mercury standard would impose substantial costs on the 

industry with no reasonable expectation that any actual reduction in mercury would be achieved. As we 

have explained in several prior submittals to EPA, no emissions controls have demonstrated to be 

effective in controlling mercury emissions from the brick industry.

In short, EPA does not have sufficient information on mercury emissions from the brick industry to set a 

standard under § 112(d). Accordingly, EPA should not attempt to set a mercury standard in the 

upcoming Brick MACT rulemaking and, instead, should defer proposing a mercury standard until 

adequate data are available.

If the Agency nevertheless decides to go forward with a mercury standard in the current rulemaking, we 

believe there is ample authority and justification to set a work practice standard rather than a numeric 

standard. Although inadequate, the available data indicate that mercury emissions levels from typical 

brick manufacturing plants are exceedingly low. As a result, EPA has no basis to conclude that 

measuring mercury emissions from brick plants is technically or economically practicable. Under these 

circumstances, a work practice standard can be easily justified under § 112(h).
We note that EPA acknowledged at the small business panel with our industry that the control of 

mercury could potentially drive the need for add-on control devices in our industry, particularly if EPA 

considers a health-based approach for the acid gases. In any economy, a requirement to control trace 

amounts of mercury emissions for millions of dollars would need strong justification. As our industry is 

recovering from one of the worst economic situations in history, spending any money with no benefit 

could needlessly close facilities that otherwise could remain viable businesses in our economy. This 

cannot be justified.

The Case for a Work Practice Standard

Earlier in this rulemaking, BIA made a strong case for mercury work practices as opposed to numerical 

limits due to limited low quantity data, extremely low concentrations and numerous test non-detects. 

EPA apparently conducted an extensive review of the limited test data for mercury to demonstrate that 

many of the tester delineated non-detects could potentially be used as valid data points in the 

development of a numerical emission limit. We still take issue with this approach and insist that this 

need for a second, cost intensive review demonstrates the high potential for problems when dealing 

with such small numbers. Staff at most brick plants would not be able to conduct such a review. This 

demonstrates both the technical and the economic infeasibility of using these data and these test 

methods for such small quantities. Use of these “corrected” data would lead to numbers that would not 

be achievable even with mercury controls, nor could compliance be demonstrated via the current test 

methods and expertise of the many testing firms out there. To this end we are still strongly suggesting 

that a work practice consideration for mercury be included in the proposed rule language.

A Mass Balance Approach Can Help Characterize Emissions

Because of the lack of data and the extreme impact that unwarranted mercury regulations could have 

on our industry, the brick industry is currently conducting additional but still limited research in an 

attempt to understand the implications of what could be in a promulgated MACT rule. In this research, 

we are attempting to quantify what the true mercury emission rates could be from this industry. At this 

point, we believe EPA has no data to predict the potential level of compliance with any mercury limit it 

may establish, except possibly for kilns already controlled with a DIFF, the only scenario evaluated by 

EPA. 

As is well known, stack testing for mercury is both expensive as well as problematic at the mercury 

emission concentrations from a brick kiln. In a scenario with a controlled kiln, the issue becomes even 

more costly if concurrent inlet and outlet testing is desired to really understand what is occurring. The 

economic condition our industry has been in has precluded these testing options. To this end, we have 

evaluated whether we can measure the mercury content present in our raw materials and develop a 

mass balance relationship, thus enabling a prediction of emissions. Given the extremely limited 

resources in our industry, this was our only viable option. As a quick summary that could be further 

discussed with EPA post proposal we have found the following:
1. The mercury content in brick making clays and shales in PPB was found to be very similar 

although maybe slightly lower on average than the numbers provided to us by EPA for 

similar materials tested as part of the Portland Cement MACT development.

2. In most cases, fired brick showed almost no measurable retained mercury. As such it is 

assumed that essentially all mercury present in the raw material evolves as a mercury 

emission.

3. Testing of fresh reagents revealed that the reagent does bring some, however small, 

amount of mercury into play in a mass balance calculation when control is present.

4. Testing of spent reagents and the application mass balance scenarios revealed that the 

capture of mercury in existing, installed controls is negligible in most cases.

Assuming that all the input mercury content will show up as a stack emission, a mass balance calculation 

was developed to compare predicted levels to actual levels from the previously determined Method 29 

stack testing that is included in the EPA brick testing spreadsheet of sources. What was found was a 

reasonably close correlation (within an order of magnitude) of concentrations and total quantities 

released. It should be noted that the extremely limited amount of stack tests clearly limited this 

assessment. What was however interesting is that the mass balance predictions was almost always 

lower that the stack tested levels meaning that more was released than what went in-- which is clearly 

not possible. One explanation is that the quantity of natural gas used in the process may bring some 

mercury into the equation. A more likely explanation is that the stack testing accuracy at these detection 

levels and the use of non detect scenarios simply overstates what is really there. Again it has to be 

questioned if anything other than a work practice scenario is warranted or if future compliance to a 

number can be achieved.

The Mass Balance Helps Illustrate That Numeric Standards Would Be Unworkable

The result of the raw material testing and mass balance predictions means that the industry is now 

better equipped to analyze and predict the implications of what EPA may put in the proposed rule 

regarding mercury. At this point having received no signaling from EPA as to what may be in the 

proposed rule all we can do is speculate as to what may be there and the impact such may have on both 

small and large entities. What we can predict and comment on are the following:

1. Were numerical limits proposed most locations of both small and large entities could not 

make the numbers nor could testers demonstrate compliance? This is based on our 

assessment of what a potential mercury emission limit would be using EPA’s standard 

approach used in other rulemakings (i.e., pollutant specific MACT-floor).

2. There is no demonstration of mercury control scenarios in our industry and arguably other 

industries with similar emission profiles that can achieve what could be numerical limits, if 

those limits were not met as a result of the naturally occurring mercury content in the raw 

material.
3. Subcategorization of large and small kilns (as used in the 2003 MACT ) could result in a more 

achievable controlled scenario for smaller kilns; however, many entities that have both large 

and small kilns could still face unachievable control requirements and costs that would make 

the viability of their businesses doubtful.

4. Subcategorization by large and small kilns would only marginally benefit small businesses, as 

small entities in the industry have both small and large kilns. 

5. The EPA database for mercury (as we know it to be populated) contains only controlled 

sources and would obviously understate the impact the proposed rule may have. Most of 

the small and large entities that are omitted from the more recent version BIA has of the 

database are in fact those that were below 10 TPH, which were not required to be 

controlled in the now- vacated 2003 rule. These kilns would now be subject to control in the 

new rulemaking.

6. In general the use of incomplete industry data and questionable assumptions will result in 

an understatement of cost impact and an overstatement of benefits.

Conclusion

In summary we ask that the proposed rule be as broad in nature as possible such that all possibilities 

and options can be explored during the period between proposal and promulgation. We strongly urge 

EPA to defer setting any standard for mercury at this time. Alternatively, if the Agency decides to 

address mercury in the current rulemaking, a work-practice standard is all that can be justified and is all 

that should be proposed. 

The bottom line for our industry is that we have no experience and know of no experience in any other 

industry of mercury control being effective at our concentrations and with our other exhaust 

parameters. Therefore, if EPA were to propose a numerical limit, the ability to meet the standard would 

likely completely come down to the random chance of the trace level mercury content in the mined 

material we use for our product. Those above the limit, based again on only data from controlled 

sources, would be forced to either shut down operations or engage in a costly, speculative process of 

installing a multimillion dollar control device that has never been demonstrated to work on emission 

streams such as ours. Any potential benefit of possibly removing minute amounts of mercury would be 

negligible and certainly would not offset the devastating impact a numeric mercury standard would 

have on the viability of a US company producing a strong, sustainable product.

BIA is looking forward to a meaningful dialog and data analysis with EPA, now or post proposal, in an 

effort to develop an environmental responsible rule with justifiable cost benefit reasonableness as well 

as achievable for both small and large entities.