1 MEMORANDUM

TO: Jim Eddinger, U.S. Environmental Protection Agency, OAQPS

FROM: Eastern Research Group, Inc.

DATE: August 2012

SUBJECT: Revised (August 2012) Data Dictionary for Boiler, Process Heater, and Other

Combustion Unit Survey Databases

1.0 INTRODUCTION

This memorandum discusses the changes to the structures of the EPA ICR Databases

since the December 23, 2011 proposed reconsideration of the rule (76 FR 80598). A discussion

of the structures of the databases generated for the proposed reconsideration of the rule is

provided in the memorandum, “Revised (November 2011) Data Dictionary for Boiler, Process

Heater, and Other Combustion Unit Survey Databases” in the docket. 1 This memorandum only

discusses the changes in database structure, and incorporates the docketed memorandum

from the proposed reconsideration of the rule by reference.

This memorandum is organized as follows:

1.0 Introduction

2.0 Summary of Changes to Database Structure

3.0 References2 2.0 SUMMARY OF CHANGES TO DATABASE STRUCTURE

Since the proposed reconsideration of the rule, only minimal changes have occurred to

the structures of the Survey Database Containing Results of the 2008 Questionnaire for Boilers,

Process Heaters, and Other Combustion Units (Survey Results Database) and Emissions

Database for Boilers and Process Heaters Containing Stack Test, CEM, and Fuel Analysis Data

(Emissions Database). 2,3 This section of the memorandum discusses the specific changes to the

database structures since the proposed reconsideration of the rule.

2.1 Change Code Fields Added to Survey Results Database

In the Survey Results Database, two additional fields have been added to each data

table, entitled “ Change Code ” and “ Notes for Changes Made ”. A description of these fields is

provided in an older memorandum in the docket, entitled “Handling and Processing of

Corrections and New Data in the EPA ICR Databases

– Revised November 2011”. 4 Since

corrections to reported data were applicable to not only emissions or fuel analysis data, but

also to unit

‐ level characteristics such as fuels combusted or control devices employed, it was

necessary to denote where changes in these unit

‐ level characteristics have changed since they

were reported under the 2008 Questionnaire for Boilers, Process Heaters, Incinerators and

Other Combustion Units 5 or subsequent data request.

2.2 Identifier for Liquid Units Switching to Natural Gas Combustion

A new column was added to the Inventory: Major Source Boilers and Process Heaters

table to denote which units initially classified in a liquid fuel subcategory were expected to

switch to natural gas consumption in lieu of demonstrating compliance with emission

limitations for the regulated pollutants. The new field is entitled “ Liq Unit Can Routinely Burn

NG? ”. A description of the processes used to identify the liquid units that are candidates for

fuel switching is provided in another memorandum. 6

2.3 New Fields for Revised CO and THC Measurement Error Analysis3 Based on the revised analysis used to incorporate instrument measurement error into

reported CO and THC emissions, additional fields were created in the Major Source Data:

EmissionsTest table in the Emissions Database. A discussion of the revised measurement error

analysis is provided in another memorandum. 7 A list of the new fields is provided below along

with a description of the data each field contains.

 “ Final Rule CO Span ”: The CO or THC measurement error (ppm) used for the test run

from the databases docketed for the March 21, 2011 final rule notice (76 FR 15608).

This field is provided for sake of comparison.

 “ Recon Proposal CO Span ”: The CO or THC measurement error (ppm) used for the

test run from the databases docketed for the December 23, 2011 proposed

reconsideration of the rule (76 FR 80598). This field is provided for sake of

comparison.

 “ Date Flag ”: Identifies whether or not the test run was conducted before or after

May, 2008. This field applies only to test runs for which a test

‐ specific measurement

error was not determined, and were otherwise using a default measurement error

for a subcategory. This field applies to CO only.

 “ Fuel for CO Span ”: Fuel category correlating the test run to a default measurement

error subcategory. This field applies to both CO and THC.

 “ Oxygen % ”: Reported stack oxygen concentration (%) for the test run. If no stack

oxygen data were reported with the test, this column was left blank. This field

applies to both CO and THC.

 “ O2 Source ”: Identifies the source from which stack oxygen concentration data

were obtained. Oxygen data were either reported in another database table, or the

data were extracted as a part of a test report review process. This field applies to

both CO and THC.

 “ CO at Stack O2% ”: For test runs where the stack oxygen concentration was known,

the standardized CO or THC emissions (in ppm @ 3% oxygen) were standardized

back to stack oxygen levels. The equation used for this conversion is provided in

another memorandum. 7

 “ Recon Final CO Span ”: The CO or THC measurement error (ppm) used for the test

run for the final rule.4  “ CO Span Source ”: Identifies the source from which the CO or THC measurement

error for the test run obtained. The measurement error was either a test

‐ specific

value generated as a result of test report review, or a default measurement error

developed for a subcategory.

 “ Needs Min CO Value? (Runs With O2) ”: For test runs for which stack oxygen

concentration data were available, this field identifies whether or not it is necessary

to default to the CO or THC measurement error value in lieu of the reported

emission concentration.

 “ Final CO at Stack O2 ”: For test runs where the stack oxygen concentration was

known, either the CO or THC measurement error or the reported emission

concentration at stack oxygen levels was standardized back to three percent oxygen.

The equation used for this conversion is provided in another memorandum. 7

 “ Needs Min CO Value? (Runs Without O2) ”: For test runs where the stack oxygen

concentration data were not available, this field identifies whether or not it is

necessary to default to the CO or THC measurement error value in lieu of the

reported emission concentration.5 3.0 REFERENCES

1. Eastern Research Group, Inc. Revised (November 2011) Data Dictionary for Boiler,

Process Heater, and Other Combustion Unit Survey Databases. November 2011.

2. Survey Database containing Results of the 2008 Questionnaire for Boilers, Process

Heaters, & Other Combustion Units (ICR No. 2286.01) (Version 4).

3. Emissions Database for Boilers and Process Heaters Containing Stack Test, CEM, & Fuel

Analysis Data Reported under ICR No. 2286.01 & ICR No. 2286.03 (Version 8).

4. Eastern Research Group, Inc. Handling and Processing of Corrections and New Data in

the EPA ICR Databases

– Revised November 2011. November 2011.

5. U.S. Environmental Protection Agency. 2008 Questionnaire for Boilers, Process Heaters,

Incinerators and Other Combustion Units. ICR No. 2286.01. OMB Control No. 2060

‐

0616. EPA Form No. 5900

‐ 122.

6. Eastern Research Group, Inc. Revised (August 2012) Methodology for Estimating Cost

and Emissions Impacts for Industrial, Commercial, Institutional Boilers and Process

Heaters National Emission Standards for Hazardous Air Pollutants

– Major Source.

August 2012.

7. Eastern Research Group, Inc. Incorporating Measurement Error in Reported Carbon

Monoxide (CO) and Total Hydrocarbon (THC) Data (Revised August 2012). August 2012.