Date: September 24, 2015

To: Sharon Nizich, EPA/OAQPS/SPPD

From: Gabrielle Raymond and Kristin Sroka, RTI International

Subject: Comparison of PM Data for BSCP T unnel Kilns With and Without Fabric Filters

I. Introduction

In accordance with section 112 of the Clean Air Act (CAA), the U.S. Environmental Protection Agency (EPA) established national em ission standards for hazardous air pollutants (NESHAP) on May 16, 2003 for the brick and struct ural clay products (BSCP) manufacturing industry. The NESHAP regulated emissions of hydrogen fluoride (HF), hydrogen chloride (HCl), and particulate matter (PM)—a surrogate for ha zardous air pollutant (HAP) metals—from tunnel kilns located at BSCP faciliti es. On March 13, 2007, the D.C. Circuit Court vacated the emission standards for BSCP manufacturing due to issu es associated with the methodology used to determine the minimum regulatory “f loors” for new and existing units. 1 Therefore, on December 18, 2014 the EPA proposed new standards for BSCP manufacturing, includi ng standards for HF, HCl, chlorine (Cl 2 ), mercury (Hg), and non-Hg HAP metals (or PM surrogate). The EPA provided a 90-day public comment period fo llowing proposal of the BSCP Manufacturing NESHAP, during which all affected parties we re given the opportunity to comment on the proposed rule. The EPA has considered the comme nts received and, as appropriate, incorporated them into the final rule.
The objective of this memorandum is to compar e the PM data for BSCP tunnel kilns with fabric filter (FF)-based air po llution control devices (APCD) to the PM data for uncontrolled kilns and kilns with other types of APCD.
II. Analysis
In other source categories, the EPA has f ound that as a group, FF-based APCD, including dry injection/fabric filters (DIFF), dry lime sc rubbers (DLS) with FF, and stand-alone FF are better performers in terms of controlling PM emissions than non-FF-based APCD such as dry limestone adsorbers (DLA), wet scrubbers (WS) , and spray dryer/electrostatic precipitators (SD/ESP), as well as uncontrolled kilns.

1 Sierra Club v. EPA , 479 F.3d 875 (D.C. Cir. 2007).To evaluate whether this obser vation applies to BSCP tunnel kilns as well, we used a box and whisker plot, which is a sta tistical test for plotting data. We created one box and whisker plot for all the PM data from FF-based APCD a nd another plot for all the other APCD and uncontrolled kilns and compared the plots to each other. The box is made up of three points, Quartile 1 (Q1), Quartile 2 (Q2), and Quartile 3 (Q3). Twenty five percent of the data lie between the minimum data point and Q1. Fifty per cent of the data lie between Q1 and Q3, which is referred to as the Interquartile range (IQR). Tw enty five percent of the data lie between Q3 and the maximum data point. The Minimum Whisker is equal to the minimum data point. The Maximum Whisker is equal to the maximum data point. Table 1 displays the values graphed in the Figure 1 box and whisker plots for th e two sets of data by APCD group.

Table 1. Parameters of Box and Whisker Plots
Parameter Kilns with FF-based APCD Kilns with Other APCD or Uncontrolled Minimum Whisker 0.0076 0.0128 Q1 0.0184 0.0960 Median 0.0426 0.1781 Q3 0.0764 0.3770 Maximum Whisker 0.2397 1.1877 IQR 0.0579 0.2810 Mean 0.0587 0.2754

Figure 1. Box and Whisker Plots of BSCP Tunnel Kiln PM Data by APCD Group 0.0 0.2 0.4 0.6 0.8 1.0 1.2

FF

‐ based Other APCD/ UncontrolledAveragePMforeachkiln(lb/ton)

MeanOverall, the range of data for the kilns with FF-based APCD is sma ller than the range of data for the kilns with other APCD and uncontrolled kilns. However, one limitation of this analysis is lack of data on a ll BSCP tunnel kilns, particularly several kilns with DIFF. One kiln with a DIFF but with no PM test data is located at Brampton Bricks, Inc., which is an addition to the inventory since proposal. In addition, some of the quality assurance/ quality control (QA/QC) checks described in Test Data Used in BSCP Manufacturing Final Rule (Raymond, 2015), particularly the evaluation of EPA Method 5 pr obe and filter temperatures, resulted in the removal of some PM test data on tunnel kilns wi th DIFF. Therefore, we cannot say with certainty that the kilns with FF-based APCD represent the best performers

. III. References
Raymond, G. 2015. Test Data Used in BSCP Manufacturing Final Rule . Memorandum from Gabrielle Raymond, RTI International, to Sharon Nizich, EPA/OAQ PS/SPPD. September 24, 2015.