Appendix 1 Emissions Inventory Support MemorandumChromium Electroplating1 MEMORANDUM

TO: Anne Pope, EPA

FROM: Darcy Wilson, ERG

DATE: July 19, 2010

SUBJECT: Emissions Data Used in Residua l Risk Modeling for Modeling for Chromium Electroplating

The purpose of this memorandum is to provide information on the RTR database used in estimating residual risk for the the three Ch romium Electroplating Maximum Achievable Control Technology (MACT) source categor ies—Chromic Acid Anodizing, Decorative Chromium Electroplating, and Hard Chromium Electroplating.

BACKGROUND

Section 112 of the Clean Air Act (CAA) establ ishes a two-stage regu latory process to address emissions of hazardous air pollutants ( HAPs) from stationary sources. In the first stage, section 112(d) requires the Environmental Protecti on Agency (EPA) to develop technology-based standards for categories of industrial sour ces. In the second stage, known as the residual risk stage, section 112( f)(2) requires EPA to a ssess the health and

environmental risks that remain after sour ces come into compliance with MACT. If

additional risk reductions are ne cessary to protect public health with an ample margin of safety or to prevent adverse environmenta l effects, EPA must develop standards to address these remaining risks. As part of this second stage, data were gathered to assess

the residual risks from the three Chromium Electroplating MACT source categories.

EMISSIONS DATA USED IN RESIDUAL RISK MODELING

The 2005 National Emissions Inventory (NEI) data served as the star ting point for this assessment. Using the process MACT code, 1 a subset of the NEI was developed that contained facility, process, and emissions da ta for each facility in the Chromic Acid Anodizing source category (MACT code 1607), the Decorative Chromium Electroplating source category (MACT code 1610), and the Hard Chromium Electroplating source category (MACT code 1615).

EPA evaluated the 2005 NEI Chromium Electropl ating subset and noted that the NEI had a very limited representation of Chromium Elect roplating facilities. An additional data set of Chromium Plating facilities was developed to address this situation. This information was gathered from EPA Regional offices, State and local agencies, EPA and online industry databases, and an Information Co llection Request (ICR) for the Plating and

1 Assigning data with MACT codes allows EPA to determine reductions attributable to the MACT program. The NEI associates MACT codes corresp onding to MACT source categories with stationary major and area source data.2 Polishing Area Source NESHAP. Emission es timates were developed for over 1,629 additional “model” plants based on this data set using information known about the type of plating operation at ea ch facility, and surrogate stack parameters. Locational

coordinates were obtained based on the facility address. Fo r 44 of the model plants, EPA was able to develop improved emission estimat es (rather than using surrogate emission estimates) based on compiled process information for the facilities.

Risks associated with facilities cove red by the Chromium Electroplating MACT

standards were modeled in the initial 2005 NATA risk assessment in June of 2009.

NATA comments on the initial risk assessment dr aft that have been incorporated into the

2005 NEI include revisions to emissions for one chrome plating facility and identification of one closed model plant. EPA also made revisions to the emissions estimate for one other facility.

EPA also evaluated the whole facility risks for Chromium Electroplating facilities using

the 2005 NEI data and risk assessment results that were released in the 2005 NATA Risk Preview with State and local agencies in J une of 2010. Emission revisions were made to for one facility based on the 2005 NATA Risk Preview comments, and 17 model plants were identified as having closed. Base d on industry contacts, EPA identified two

additional facilities that have closed, removed one facility from the Chromium Electroplating source category, and made revisions to the emission estimates for nine

facilities. These revisions were not included in the risk analyses, but will be reflected in

the final NATA risk assessment.