P.1 

OAR Box 1813 

Prepped by Ollie Stewart 

Document Number: 

166) F. R. December 16, 1993 

Docket Number: 

A-88-02 

Printed 11/5/2008 1:25:06 PM Sheet 166 of 166 
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Thursday 

December 16, 1993 

¥ 3 LLJ 

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Part II 

Environmental 

Protection Agency 

40 CFR Part 63 

Proposed Standards for Chromium 

Emissions From Hard and Decorative 

Chromium Electroplating and Chromium 

Anodizing Tanks; Proposed Rule 

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65768 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rule. 

P.3 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 63 

[AD-FRL-4810-5J 

RIM 2860-AC14 

National Emission Standards for 

Hazardous Air Pollutants; Proposed 

Standards for Chromium Emissions 

From Hard and Decorative Chromium 

Electroplating and Chromium 

Anodizing Tanks 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Proposed rule and notice of 

public hearing. 

SUMMARY: The proposed standards 

would limit emissions of chromium 

compounds from new and existing 

chromium electroplating and anodizing 

operations; botii major and area sources 

are being regulated. The proposed 

standards implement section 112 ofthe 

Clean Air Act, as amended. The intent 

of the standards is to protect die public 

healdi by minimizing die amount of 

chromium emitted from new and 

existing chromium electroplating and 

anodizing operations. These sources 

must achieve an emissions level 

consistent widi the installation and 

operation of maximum achievable 

control technology (MACT). The EPA is 

also proposing Methods 306, 306A, and 

306B with die standards. These methods 

would be used to demonstrate 

j compliance widi die standards. 

7\DATCS: Comments: Comments must be A* 

received on or before February 14,1994. 

Public Hearing: If anyone contacts 

EPA requesting to speak at a public 

hearing by January 6,1994, a public 

hearing will be held on January 18, 

1994, beginning at 10 a.m. 

ADDRESSES: Comments: Comments 

should be submitted (in duplicate if 

. possible) to: Air Docket (LE-131), 

Attention: Docket Number A-88-02, 

U.S. Environmental Protection Agency, 

401 M Street, SW., Washington, DC 

20460. 

Public Hearing: If anyone contacts 

EPA requesting a public hearing, the 

hearing will be held at die EPA Office 

of Administration Auditorium in 

Research Triangle Park, North Carolina. 

Persons interested in attending die 

hearing or wishing to present oral 

testimony should notify Mrs. Julia Latta, 

Standards Development Branch (MD13), U.S. Environmental Protection 

Agency, Research Triangle Park, North 

Carolina 27711, telephone number (919) 

541-5578. 

Background Information Document: 

The background information document 

(BID) and otiier documents supporting 

die proposed standards may be obtained 

from die docket or from die U.S. EPA 

Library (MD-35), Research Triangle 

Park, North Carolina 27711, telephone 

number (919) 541-2777. Please refer to 

"Chromium Electroplating NESHAP— 

Background Information Document for 

Proposed Standards" (Volume I: EPA453/R-93-030a and Volume II: EPA453/R-93-030b) and to "Chromium 

Electroplating NESHAP—New 

Technology Document" (EPA-453/R93-031). 

Docket: Docket No. A-88-02, 

containing supporting information used 

in developing the proposed standards, is 

available for public inspection and 

copying between 8 a.m. and 4 p.m., 

Monday dirough Friday, at EPA's Air 

Docket Section, West Tower Lobby, 

Gallery 1, Waterside Mall, 401M Street, 

SW., Washington, DC 20460. A 

reasonable fee may be charged for

 v 

copying. 

FOR FURTHER INFORMATION CONTACT: For 

information concerning regulatory 

decisions and the proposed standards, 

contact Mr. Lalit Banker, Standards 

Development Branch ((919) 541-5420). 

For information concerning technical 

aspects of chromium electroplating and 

anodizing tanks or control technologies, 

contact Mr. Phil Mulrine, Industrial 

Studies Branch ((919) 541-5289). The 

address for each of these contacts is 

Emission Standards Division (MD-13), 

U. S. Environmental Protection Agency, 

"Research Triangle Park, North Carolina 

27711. 

SUPPLEMENTARY INFORMATION: The 

information presented in this preamble 

is organized as follows: 

I. Background 

tt. National Emission Standards for 

Hazardous Air Pollutants Decision 

. Process 

A. Source of AuUiority for NESHAP 

Development 

B. Criteria for Development of NESHAP 

C Categorization/Subcategorizatlon: 

Determining Maximum Achievable 

Control Technology Floors 

D. Regulatory Approach and Regulatory 

Alternatives 

HI. Overview of Proposed Standards 

A. Applicability ofthe Standards 

B. Format of the Standards ' 

C Actual Standards and Their Bases 

D. Test Methods for Compliance 

E. Monitoring Requirements 

F. Reporting and Recordkeeping 

Requirements 

IV. Impacts of Uie Standards 

A. Hard Chromium Electroplating Tanks 

B. Decorative Chromium Electroplating 

Tanks 

C. Chromium Anodizing Tanks 

V. Process Description and Description of 

Control Technologies 

A. Process Descriptions 

B. Description of Control Technologies 

VI. Rationale for Selection of die Proposed 

Standards 

A. Selection of Pollutant and Source 

Categories to be Regulated 

B. Selection of Emission Points to be 

Covered by die Standard 

C. Selection of Basis and Level of Proposed 

Standards for Existing and New Sources 

D. Selection ofthe Format ofthe Proposed 

Standards 

E. Selection of the Emission Limits 

F. Selection of Definition of Source 

G. Selection of Monitoring Requirements 

H. Selection of Test Metiiods 

I. Selection of Reporting and 

Recordkeeping Requirements 

J. Operating Permit Program 

K. Solicitation of Comments 

VD. Administrative Requirements 

A. Public Hearing 

B. Docket 

C Executive Order 12866 

D. Paperwork Reduction Act 

E. Regulatory Flexibility Act 

F. Miscellaneous 

I. Background 

In 1984, die EPA began ah 

investigation of chromium 

electroplating operations as a source of 

chromium emissions in conjunction 

with a notice of intent to list total or 

hexavalent chromium as a hazardous air 

pollutant (HAP) under section 112 of 

the Clean Air Act (50 FR 24317). This 

study focused on chromium emissions 

from chromium electroplating and 

anodizing tanks. (Due to the focus of 

this study, information was not obtained 

On HAP emissions from odier metal 

plating processes such as nickel, copper, 

and cadmium plating. As a result, these 

processes are not included in today's 

proposal.) During this study, it was 

determined that chromium 

electroplating and anodizing tanks were 

significant emitters of chromic acid, the 

principal ingredient in chromium 

electroplating and anodizing baths. 

Chromic acid is a hexavalent chromium 

compound. The EPA has determined 

that there is strong evidence to conclude 

diat hexavalent chromium compounds 

cause lung cancer in humans. This 

conclusion was documented in die 

notice of intent to list total or 

hexavalent chromium (50 FR 24317). 

Trivalent chromium compounds are 

emitted in low levels from those 

decorative electroplating tanks diat use 

trivalent chromium electroplating 

solutions. The data on die 

carcinogenicity of trivalent chromium 

are inconclusive at this time; however, 

it is known diat trivalent chromium can 

accumulate in die lungs and could 

potentially result in decreased lung 
P.4 

isir / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

function under ejctended exposure 

conditions. 

On Novembsr 25, SSS9, th© Clean Air 

Act was amended. Section 112(b) of tha 

amended Act provides a list of 189 

compounds tiiat are considered to be 

HAP. Chromium compounds are 

inch__s_ on this list of pollutants. 

Under sactioa 112(c) of tha Act, ths 

Administrator is required to publish End 

from te to time revise _ list of source 

categories and subcategories that emit 

one or mors cf tha HAP listed in section 

112(b). Qa July 36.2892, EPA published 

in ths Fefaol E_gicti_r (57 FR 31576) an 

initial list of major and area source 

categories to _3 r_g_latsd, which 

included major Enid a_s_ sources of hard 

chromium elscEraplatfng. decorative 

chromium ©lsc_ropl&ting, and 

chromium anodizing. Emission 

standards under ssction 112(d) ofthe 

Act are being proposed for all six of 

these source categories. The study of 

tiiese source categories tiiat had begun 

in 1984 continued sad became the basis 

for this proposed ml®. 

Subcategorization of each of the above 

categories roes studied. Tha EPA study 

concluded diat major and area sources 

of emissions from hasd chromium 

electroplating and chromium anodizing 

tanks should: not bs subcategorized. 

However, it was determined that major 

and area sources of emissions from 

decorative chromium electroplating 

tanks should be subcategorized 

according to whether a trivalent 

chromium, or chromic acid 

electroplating bath solution is used. The 

chromic acid and trivalent chromium 

processes are considered separate 

source subcategories because the 

trivalent chromium process differs in 

several wayo from the chromic acid 

electroplating process. For example, the 

electroplating bath chemistry for 

trivalent baths is comprised mostly of 

trivalent chromium; hexavalent 

chromium is considered a bath 

contaminant, whereas it is the main 

ingredient in a chromic acid bath. In 

addition, the process line for a trivalent 

chromium electroplating process differs 

from that used with a chromic acid 

electroplating bath. In particular, 

.additional rinse tanks or post dips are 

added to the electroplating line in die 

trivalent chromium electroplating 

processes (for mors information, see 

discussion of trivalent chromium 

electroplating tanks is section V.A.2 of 

this preamble).' 

The Ageacy's findings indicate diat a 

majority of th© sources in the six source 

categories era ao2 major sources as 

defined to section 312(a)(2); i.e., they do 

not emit as Ikwo _ia potential to emit 

•greate? Skam 0.2 MsgQgE___j par ye_? 

(Mg/yr) (10 tons per year (tons/yr)) of 

chromium compounds. Some sources 

would be considered major if die source 

is located at a facility that is major. In 

such cases, the source would be 

regulated as a major source. Based on 

the fact that most sources would not be 

considered major and considering the 

toxicity of chromium compounds, EPA 

has chosen to regulate area sources as 

well as major sources as documented in 

tiie area source finding for these six 

source categories (57 FR 31576). 

Further, the proposed rule would 

regulate both major and area sources by 

applying maximum achievable control 

technology (MACT). 

IH. N_(!MJEI_! Esmissi-S Sl_m_aards for 

Ha__E_!___ Ms PoffiatoEte ©scisi-m 

A. Source of Authority for NESHAP 

Development 

Section 112 ofthe 1990 Clean Air Act 

gives EPA the authority to establish 

national standards to reduce air toxics 

from sources that emit one or more 

HAP. Section 112(b) contains a list of 

HAP that are die specific air toxics to be 

regulated by national emission 

standards for hazardous air pollutants 

(NESHAP). Section 112(c) directs EPA 

to use this pollutant list to develop and 

publish a list of source categories for 

which NESHAP will bs developed The 

EPA must list all known categories and 

subcategories of "major sources" 

(defined below) which emit one or more 

ofthe listed HAP. Area source 

categories selected by EPA for NESHAP 

development will bs based on ths 

Administrator's judgment that the 

sources in a category, individually or in 

aggregate, pose a "threat of adverse 

effects to health and the environment." 

B. Criteria for Development of NESHAP 

The NESHAP are to be developed to 

control HAP emissions from both new 

and easting sources according to the 

statutory directives set out in ssction 

122 off the Act. Ths statute requires the 

standard to reflect the maximum degree 

of reduction in emissions of HAP tiiat is 

achievable for new or existing sources. 

The NESHAP must reflect consideration 

ofthe cost of achieving the emission 

reduction, any nonair quality health and 

environmental impacts, and energy 

requirements for control levels more 

stringent tiian the MACT floor 

(described below). The emission 

reduction maybe accomplished through 

application of measures, processes, 

methods, systems or techniques, 

including, but not limited to, measures 

which: 

(A) Reduce the volume of, or 

eliminate emissions of, such pollutants 

through process changes, substitution of 

materials, or other modifications; 

(B) Enclose systems or processes to 

eliminate emissions; 

(C) Collect, capture, or treat such 

pollutants when released from a 

process, stack, storage, or fugitive 

emissions point; 

(D) Are aesign, equipment, work 

practice, or operational standards 

including requirements for operator 

training or certification as provided in 

section 112(h); or 

(E) Are a combination of the above 

(section 112(d)(2)). 

To develop NESHAP, EPA collects 

information about the industry,. 

including information on emission 

source characteristics, control 

technologies, data from HAP emission 

tests at well-controlled facilities, and 

information on the costs and other 

energy and environmental impacts of 

emission control techniques. The EPA 

uses this information to analyze 

possible regulatory approaches. 

Although NESHAP are normally 

structured in terms of numerical 

emission limits, alternative approaches 

are sometimes necessary. In some cases, 

physically measuring emissions from a 

source may be impossible or at leest 

impracticable due to technological and 

economic limitations. Section 112(h) 

authorizes the Administrator to 

promulgate a design, equipment, work 

practice, or operational standard, or 

combination thereof, in those cases 

where it is not feasible to prescribe or 

enforce an emissions standard. 

If sources in ths source category are 

major sources, then a MACT standard is 

required. For area sources, the 

Administrator has the option of 

establishing either a MACT standard or 

a standard based on generally available 

control technologies (GACT) (section 

112(d)(5)). To establish a MACT 

standard, the level of control 

corresponding to tiie MACT floor needs 

to be determined as a starting point for 

developing the regulatory alternatives. 

C. Categorizatioit/Subsategoxization: 

Determining Maximum Achievable 

Control Technology Floors 

Section 212 of the Act provides 

certain very specific directives to guide 

EPA in the process of establishing 

MACT standards. It states that EPA shall 

establish standards which require "the 

maximum degree of reduction in 

emissions ofthe hazardous air 

pollutants ° ° ° that the Administrate, 

taking into consideration the coat of 

achieving such. ES-issicm reduction, and 

any nonair quality health end 
P.5 

65770 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

environmental impacts and energy 

requirements, determines is achievable 

* * *" (section 112(d)(2)). In addition, 

a minimum baseline or "floor" for 

standards is specified. For new sources, 

the standards for a source category or 

subcategory "shall not be less stringent 

than the emission control that is 

achieved in practice by the best 

controlled similar source, as determined 

by the Administrator" (section 

112(d)(3)). Existing source standards 

shall be no less stringent than the 

average emission limitation achieved by 

the best performing 12 percent ofthe 

existing sources in the category or 

subcategory for categories and 

subcategories with 30 cr more sources, 

or the best performing 5 sources for 

categories or subcategories with fewer 

than 30 sources (section 112(d)(3)). 

In rules currently under development, 

EPA is considering two interpretations 

of the statutory language concerning the 

MACT floor for existing sources. One 

interpretation groups the words 

"average emission limitation achieved 

by" together in a single phrase and asks 

what is the "average emission limitation 

achieved by" the best performing 12 

percent. This interpretation places the 

emphasis on "average". It would 

correspond to first identifying the best 

performing 12 percent of tiie existing 

sources, then determining the average 

emission limitation achieved by these 

sources as a group. Another 

interpretation groups the words 

"average emission limitation" into a 

single phrase and asks what "average 

emission limitation" is "achieved by" 

all members ofthe best performing 12 

percent. In this case, the "average 

emission Umitation" might be 

interpreted as the average reduction 

across the HAP emitted by an emission 

point over time. Under this 

interpretation, EPA would look at the 

average emission limits achieved by 

each ofthe best performing 12 percent 

of existing sources, and take the lowest. 

This interpretation would correspond to 

the level of control achieved by the 

source at the 88th percentile if all 

sources were ranked from the most 

controlled (100th percentile) to the least 

controlled (1st percentile). 

The EPA believes that the first 

interpretation is appropriate and solicits 

comment on its interpretation of "the 

average emission limitation achieved by 

the best performing 12 percent of the 

existing sources" (section 112(d)(3)(A) 

of the Act). 

The EPA is also considering two 

possible meanings for the word 

"average" as the term is used in section 

112(d)(3) (A) and (B) ofthe Act. First, 

"average" could be interpreted as the 

arithmetic mean. The arithmetic mean 

of a set of measurements is the sum of 

the measurements divided by the 

number of measurements in the set. The 

EPA has determined that the arithmetic 

mean ofthe emissions limitations 

achieved by the best performing 12 

percent of existing sources in some 

cases would yield an emission 

limitation that fails to correspond to the 

limitation achieved by any particular 

technology. In such cases, EPA would 

not select this approach. The word 

"average" could also be interpreted as 

the median emission limitation value. 

The median is the value in a set of 

measurements below and above which 

there are an equal number of values 

(when the measurements are arranged in 

order of magnitude). This approach 

identifies the emission limitation 

achieved by those sources within the 

top 12 percent, arranges those emission 

limitations by magnitude, and takes the 

control level achieved by the median 

source. This is mathematically 

equivalent to identifying the emission 

Umitation achieved by the source at 

approximately the observed 94th 

percentile level of emission control. 

Either of these two approaches could be 

used in developing standards for 

different source categories. The 

"median" approach was used in these 

proposed standards. 

Once the floor has been determined 

for new or existing sources for a 

category or subcategory, the 

Administrator must set MACT standards 

that are no less stringent than the floor. 

Such standards must then be met by all 

sources within the category or 

subcategory. However, in estabhshing 

standards, the Administrator may 

distinguish among classes, types, and 

sizes of sources within a category or 

subcategory (section 112(d)(1)). Thus, 

for example, the Administrator could 

estabUsh two classes of sources within 

a category or subcategory based on size 

and estabUsh a different emission 

standard for each class, provided both 

standards are at least as stringent as the 

MACT floor. 

In addition, the Act provides the 

Administrator further flexibiUty to 

regulate area sources. Section 112(d)(5) 

provides that in Ueu of establishing 

MACT standards under section 112(d), 

the Administrator may promulgate 

standards which provide for the use of 

"generally available control 

technologies or management practices." 

Area source standards promulgated 

under this authority (GACT standards) 

would not be subject to the MACT 

"floors" described above. Moreover, for 

source categories subject to standards 

promulgated under section 112(d)(5), 

EPA is not required to conduct a 

residual risk analysis under section 

112(f). 

D. Regulatory Approach and Regulatory 

Alternatives 

At the end of the data gathering and 

analysis, EPA must decide whether it is 

more appropriate to follow the MACT or 

the GACT approach for regidating an 

area source category. In some cases, it 

may be appropriate to regulate both 

major and area sources in a source 

category under MACT. In other cases, it 

may be more appropriate to estabUsh 

area source standards based on GACT. 

In the case of the proposed rulemaking 

for chromium electroplating and 

anodizing, the Administrator has 

decided to regulate both major and area 

sources by applying MACT. 

The next step in establishing 

standards is the investigation of 

regulatory alternatives. With MACT 

standards, only alternatives at least as 

stringent as the floor may be considered. 

Information about the industry is 

analyzed to develop model plant 

populations for projecting national 

impacts, including HAP emission 

reduction levels, costs, energy, and 

secondary impacts. Several regulatory 

alternative levels (which may be 

different levels of emissions control or 

different levels of appUcabiUty or both) 

are then evaluated to determine the 

most appropriate regulatory alternative 

to serve as the basis for the standard. 

The regulatory alternatives for new 

versus existing sources may be different, 

and separate regulatory decisions must 

be made for new and existing sources. 

For both source types, the selected 

alternative may be more stringent than 

the MACT floor. However, the control 

level selected must be technically 

achievable. In selecting a regulatory 

alternative, the Agency considers the 

achievable reduction in emissions of 

HAP (and possibly other pollutants that 

are co-controlled), the cost and 

economic impacts, the energy 

requirements, and other environmental 

impacts. 

The selected regulatory alternative is 

then translated into a proposed 

regulation. The regulation implementing 

the decision typically includes sections 

of applicability, standards, test methods' 

and compliance demonstration, 

monitoring, reporting, and 

recordkeeping. The preamble to the 

proposed regulation provides an 

explanation of the rationale for the 

decision. The pubUc is invited to 

comment on the proposed regulation 

during the pubUc comment period. 

Based on an evaluation of these 
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te- / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules (BS57fl 

comments;. EPA reaches a final decision 

and promulgates the standard. 

HL QVSSTOOT? c^ffirffijpsas- SfeEsdI-irdlB 

This section provides an overview of 

the:. 

(1) AppUcabiUty ofthe standards; 

(2) Format of the standards; 

(3) Actual standards and their bases; 

(4) Test methods for compUance; 

(5) Monitoring requirements; and 

(&} Repeating and recordkeeping 

requirements. 

Detailed discussions concerning the 

statutory basis and the selection 

rationale for the proposed standards are 

provided in sections II and VI, 

respectively, of this preamble. 

A. Applicability of the Standards 

The source categories to be regulated 

are major and area sources of HAP 

emissions from faciUties performing 

hard chromium electroplating, 

decorative chromium electroplating, 

and chromium anodizing. As noted in 

the initial source category list, EPA has 

identified es a separate source category 

each of th© three different types of 

chromium electroplating and anodizing 

operations. In addition, EPA has listed 

both the major and area sources for each 

of these categories. Thus, this rule 

proposes standards for six different 

source categories identified in the July 

16,1992 source category list. 

The specific emission units that are to 

be regulated Twithin these sourc® 

categories are electroplating and 

anodizing tanks. Thera are 

approximately 2,500 facilities with hard 

chromium electroplating tanks, 2,800 

facilities with decorative chromium 

electroplating tanks, and 700 facilities 

with chromium anodizing tanks in the 

United States. Approximately 10 

percent of the decorative chromium 

electroplating tanks use a trivalent 

chromium electroplating process; the 

remainder use a chromic acid 

(hexavalent chromium) electroplating 

process. A more detailed process 

description ofthe emission sources 

being regulated is provided in section 

V.A of this preamble. 

Section 112(b) of the Act lists 

chromium compounds as HAP; these 

are the pollutants being regulated by 

this rulemaking. Chromic acid, a 

hexavalent chromium compound, is 

emitted in significant quantities from all 

hard chromium electroplating and 

anodizing tanks and from most 

decorative chromium electroplating 

tanks. Hexavalent chromium 

compounds ara highly toxic and are 

known human carcinogens. Emissions 

from these decorative electroplating 

tanks that use trivalent chromium 

electroplating solutions include 

trivalent chromium and may include 

low levels of hexavalent chromium. The 

data on the carcinogenicity of trivalent 

chromium are inconclusive at this time; 

however, it is known that trivalent 

chromium can accumulate in the lungs 

and could potentially result in 

decreased lung function under extended 

exposure conditicas. 

3. Format of ihe Standards 

The proposed standards are expressed 

in terms of emission limits. Specifically, 

a concentration format was selected for 

the proposed standards: Mass of total 

chromium emitted per unit volume of 

air, expressed as milligrams of 

chromium per dry standard cubic meter 

of air (mg/dscm). This format would 

apply to all chromium electroplating 

and anodizing turoba and would allow 

owner/operator flexibiUty in tiie 

selection of technologies or operational 

practices that achieve equivalent 

performance to those technologies 

selected as the basis of the standards. 

Emissions from hard chromium 

electroplating and anodizing tanks and 

those decorative chromium 

electroplating tanks using e chromic 

acid electroplating process are 

comprise- of haxavaleat chromium. 

Emissions from decorative chromium 

electroplating tanks that use a trivalent 

electroplating process are comprised 

primarily of trivalent chromium, with 

low levels of hexavalent chromium 

possibly present. 

An alternative format to reduce 

emissions is proposed for decorative 

chromium electroplating tanks and 

chromium anodizing tanks that use 

fume suppressants. Such tanks do not 

typically have ventilation systems; 

emission testing to determine 

compUance at these tanks would not be 

possible (see discussion in section 

VI.D). The emission limits for decorative 

chromium electroplating tanks and 

chromium anodizing tanks using fume 

suppressants are expressed in terms of 

concentration and are based on 

emission tests performed at sources 

with ventilation. Another parameter, 

surface tension, has been measured in 

conjunction with the emission rate from 

tanks using wetting-agent-type fume 

suppressants, and EPA has found that a 

relationship between surface tension 

and total chromium emission rates 

exists. Therefore, the Administrator is 

proposing that those tanks that use 

wetting-agent-type fume suppressants 

(or a wetting agent plus foaim blanket) 

comply with a surface tension 

requirement rathe? than the emission 

limit. 

C. Actual Standards and Their Bases 

In the proposed rulemaking, 

standards have been estabUahed for 

major and area sources in each category 

and subcategory identified for 

regulation. The Agency's study has 

indicated that the majority of the 

sources in each category and 

subcategory would be area sources, 

emitting less than 9.1 Mg/yr (20 tons/yr) 

of any one HAP or 22.7 Mg/yr (25 tons/ 

yr) of multiple HAP by themselves. 

Some sources ars considered major 

because they are located within the 

fenceline of a source that is major. 

However, the appropriate control 

technology is not a function of whether 

the source is a major or area source. 

Thus, the standards identified in this 

section would apply both to major and 

area sources in each category and 

subcategory. 

The Administrator lies determined 

that different standards are appropriate 

for new sources as compared to existing 

sources; this decision is, in part, based 

on the MACT floor requirements 

explained in ssction H.C. The 

Administrator has also determined that 

for existing sources in the hard 

chromium electroplating category, 

different standards are suitable bassd on 

the size of the faciUty. A less stringent 

standard is proposed for small faciUties 

in this source category. The size 

designations identified for this source 

category are independent ofthe major 

and area source designation. 

A summary ofthe total chromium 

emission limits for each ofthe 

categories and subcategories is provided 

in Table 1. 

TABLE H.—WEW AND EXISTING SOURCES—BASIS OF THE STANDARD (TOTAL CHROMIUM EMISSION LIMIT) 

Hard chromium e.lactrop!_tin& 

Small Large 

New _.. CMP°: (0.013 mgftfecm [5.7x10-o gtfetec?}) .„ | CMP: (0.013 mg/ascm [5.7xrS0-« gr/dsct]) 
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65772 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

TABLE 1.—NEW AND EXISTING SOURCES—BASIS OF THE STANDARD (TOTAL CHROMIUM EMISSION LIMIT)—Continued 

Existing 

New and existing ..... 

New and existing 

Hard chromium electroplating 

SmaH 

PBS»: (0.03 mg/dscm [1.3x10-s gr/dscf])'. 

Large 

CMP: (0.013 mg/dscm [5.7x10-4 gr/dscf]). 

Decorative chromium (chromic acid bath); all sizes of operations: 

FS*:(40 dynes/cm [2.7x10-3 ib/ft]) or (0.003 mg/dscm 

[1.3x10-* gr/dscf]). 

Decorative chromium (trivalent chromium bath); all sizes of operations: 

TVC*: (no action) (55 dynes/cm [3.8x10-3 Ibrftt]) or (0.048 

mg/dscm [2.1x10-* gr/dscf]). 

Chromium anodizing; all sizes of operations: 

FS: (40 dynes/cm [2.7x10-3 foyft]) or (0.003 mg/dscm 

[1.3x10-« gr/dscf]). 

• CMP=Composite mesh pad. 

•>PBS=Packed-bed scrubber, 

c FS=Chsm!cal fume suppressant 

•»TVS=Trivalent chromium plating process. 

1. Hard Chromium Electroplating Tanks 

a. New Tanks. All new hard 

chromium electroplating tanks, 

regardless of size, would be required to 

meet a total chromium emission Umit of 

0.013 mg/dscm (5.7x10 -- grain per dry 

standard cubic foot [gr/dscf]). This 

emission Umit is based on the use of a 

composite mesh-pad system. Composite 

mesh-pad systems have been 

demonstrated to achieve an outlet total 

chromium concentration of 0.013 mg/ 

dscm (5.7xl0-« gr/dscf). 

b. Existing Tanks. The emission limits 

for existing hard chromium 

electroplating tanks that are presented 

in the following paragraphs differ 

depending on the size ofthe faciUty. 

FaciUties with maximum cumulative 

potential rectifier capacities less than 60 

milUon Ah/yr are considered small. 

Other faciUties are considered large. A 

discussion ofthe calculation of 

maximum potential rectifier capacity is 

provided in section VI.A of this 

preamble. 

All existing hard chromium 

electroplating tanks at large faciUties 

would be required to meet a total 

chromium emission Umit of 0.013 mg/ 

dscm (5.7xl0-« gr/dscf), which is based 

on the composite mesh-pad system. 

All existing hard chromium 

electroplating tanks at small faciUties 

would be required to meet a total 

chromium emission Umit of 0.03 mg/ 

dscm (1.3xl0"s gr/dscf). This emission 

Umit is based on the use of a wellmaintained and weU-operated packedbed scrubber. 

2. Decorative Chromium Electroplating 

Tanks Using a Chromic Acid Bath 

All new and existing decorative 

chromium electroplating tanks that use 

a chromic acid electroplating process, 

regardless of size, would be required to: 

(1) Meet a total chromium emission 

limit of 0.003 mg/dscm (1.3x10-6 gr/ 

dscf) if an air pollution control device 

is the sole means to control chromium 

emissions; or (2) use a wetting-agenttype fume suppressant in the 

electroplating bath and maintain a bath 

surface tension no greater than 40 dynes 

per centimeter (dynes/cm) (2.7x10-3 

pound force per foot [lbf/ft]). Chemical 

fume suppressants in the form of 

wetting agents, used either alone or with 

a foam blanket, are expected to achieve 

outlet concentrations of 0.003 mg/dscm 

(1.3xl0-« gr/dscf) when used in 

accordance with vendor 

recommendations. 

3. Decorative Chromium Electroplating 

Tanks Using a Trivalent Chromium Bath 

Emission tests conducted on a 

trivalent chromium electroplating tank 

indicated that the total chromium outlet 

concentration from such a bath is 0.048 

mg/dscm (2.1x10-* gr/dscf). The 

maximum value of bath surface tension 

measured during the test was 55 dynes/ 

cm (3.8x10-3 lbf/ft). Because surface 

tension is related to emissions, the 

proposed standard requires that this 

value not be exceeded. Surface tension 

monitoring is required to minimize the 

potential tiiat any new process 

developments for trivalent chromium 

baths would result in an increase in 

emissions from the process. If an air 

poUution control device is the sole 

means of controlling chromium 

emissions, faciUties must meet a total 

chromium emission Umit of 0.048 mg/ 

dscm (2.1x10-5 gr/dscf). 

4. Chromium Anodizing Tanks 

All new and existing chromium 

anodizing tanks, regardless of size, 

would be required to meet a total 

chromium emission Umit of 0.003 mg/ 

dscm (1.3xl0-« gr/dscf) (if an air 

poUution device is the sole means of 

controlling chromium emissions) or 

maintain a surface tension no greater 

than 40 dynes/cm (2.7x10-3 lbf/ft) (if 

wetting agents are used to control 

chromium emissions). 

5. CompUance Schedule 

Owners or operators of existing hard 

chromium electroplating tanks would be 

required to comply with the proposed 

standards within 1 year after the 

effective date of the standards. In 

accordance with proposed § 63.7(a), the 

owner or operator would then have 120 

days after the compUance date to 

conduct a performance test.* These time 

periods are necessary to allow the 

estimated 60 percent of those facilities 

with tanks currently operating 

uncontroUed, or with less effective air 

poUution control devices than those 

required under the standards, to obtain, 

install, and test appropriate control 

systems. The EPA believes this amount 

of time is adequate and that a longer 

time is neither necessary nor desirable 

i The EPA proposed regulations for subpart A of 

40 CFR part 63 published in the Federal Register 

on August 11,1993 at 58 FR 42760. 
P.8 

:e? / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

given the highly toxic nature of 

chromium emissions and the proximity 

of these operations fo highly populated 

areas. 

The owner or operator of an existing 

decorative chromium or chromium 

anodizing tank would have 3 months to 

comply after the effective date. A 

shorter time period is appropriate for 

these tanks because fume suppressants 

already are widely used, a large number 

of vendors supply chemical fume 

suppressants, and no installation of 

equipment is needed to comply with the 

standards. 

Owners or operators of new hard 

chromium or decorative chromium 

electroplating or anodizing tanks that 

commence construction or 

reconstruction after the standards are 

proposed, and before the final standards 

are promulgated, would have to comply 

immediately upon startup unless the 

promulgated standards are more 

stringent than the proposed standards. 

In accordance with §63.7(a)(2)(ix), if the 

promulgated standards are more 

stringent than the proposed standards, 

the compUance date for tanks built after 

proposal but before promulgation would 

be 1 year after the effective date.2 The 

owner or operator would have to 

comply with the standard as proposed 

until the compliance date. The owner or 

operator would then be required to 

conduct a performance test within 120 

days after tiie compUance date. 

The owner or operator of any hard 

chromium or decorative chromium 

electroplating or anodizing tank 

constructed after the effective date of 

the standards would be required to 

comply immediately upon startup. 

6. Early Reduction Prdgram 

An early reduction program for 

existing sources is set out in section 

112(i)(5) ofthe Act. This is a voluntary 

program that allows an emission source 

to qualify for a 6-year extension from 

the compUance date to comply with the 

promulgated standard, provided it 

meets and demonstrates all the program 

requirements. Those requirements are: 

(1) The source must achieve a 90 

percent or greater reduction in HAP 

emissions (95 percent for particulate 

matter); (2) an enforceable commitment 

for this reduction is made to EPA; (3) 

the emission reduction must be 

achieved before the standard's proposal, 

unless the source quaUfies for and 

makes an enforceable commitment for 

this reduction before the proposal date 

that states the reduction will be 

achieved after proposal but before 

January 1,1994; and (4) the early 

emission reduction must be determined 

through a comparison ofthe reduced 

emissions levels achieved with the 

baseUne levels in existence no earlier 

than 1987 (unless data were submitted 

in response to a Section 114 request and 

received by the Administrator before 

November 15,1990; in which case, 1985 

or 1986 baseline data can be used). The 

early reduction program implementing 

section 112(i)(5) was promulgated on 

December 29,1992 (57 FR 61970). The 

EPA has e:xplained the early reduction 

program to affected industry sources 

and expects some sources to participate 

in the program. Those most likely to 

participate would be those that have 

recently installed effective control 

measures. 

D. Test Methods for Compliance 

Test Methods 306 and 306A, 

"Determination of Chromium Emissions 

from Decorative and Hard Chromium 

Electroplating and Anodizing 

Operations," are the proposed methods 

for determining compliance with the 

emission standards. Test Method 306B, 

"Surface Tension Measurement and 

Recordkeeping for Tanks used at 

Chromium Electroplating and 

Anodizing FaciUties," is the proposed 

method for monitoring surface tension 

af decorative chromium electroplating 

and chromic acid anodizing facilities. 

E. Monitoring Requirements 

Two types of monitoring would be 

required by this standard: Compliance 

monitoring and operation and 

maintenance (O&M) monitoring. 

CompUance monitoring would be 

conducted to ensure ongoing 

compliance with the emission Umit. 

Operation and maintenance monitoring 

would be required to ensure that the 

affected source and its emission control 

system is properly maintained and 

operated fo minimize emissions. 

1. CompUance Monitoring 

AU owners or operators that use an air 

poUution control device fo demonstrate 

compUance with the specified 

chromium emission limits would be 

required by the proposed standards fo 

conduct an initial performance test, in 

accordance with the requirements of 

§ 63.7.3 During the performance test, the 

owner or operator would establish 

values for operating parameters to be 

monitored fo ensure continued 

compUance with the standard. This 

section identifies the parameters fo be 

monitored and the frequency of 

monitoring. The procedures for 

a Ibid. "Ibid. 

monitoring are outlined in § 63.345 of 

the proposed regulation. 

An owner or operator who uses an air 

pollution control device to comply with 

the emission limits would be required to 

monitor and record once each day the 

gas velocity of the inlet stream to the 

control device. The value or range of 

values of gas velocity that correspond to 

compUance with the emission Umit 

would be estabUshed by the owner or 

operator during the initial performance 

test. If a packed-bed scrubber is used to 

comply with the standard, the owner or 

operator would also be required to 

measure once each day, using a 

hydrometer, the concentration of 

chromic acid in the scrubber water. Gas 

velocity and scrubber water 

concentration (for packed-bed 

scrubbers) have been identified by the 

Agency as the site-specific operating 

parameters that would determine 

compUance or noncompliance with the 

regulation. Should the gas velocity be 

outside of the range established during 

the performance test (i.e., either higher 

or lower than the pre-established value 

or range of values) or should the 

scrubber water concentration exceed 45 

grams per liter (g/L) (6 ounces per gallon 

(oz/gal), the owner or operator would be 

in noncompliance with the emission 

Umit. 

As an alternative to the above 

requirements, an owner or operator who 

uses an air pollution control device in 

conjunction with fume suppressants to 

control emissions from a decorative 

chromium or chromium anodizing 

operation may monitor surface tension 

ofthe electroplating bath fo demonstrate 

ongoing compliance (gas velocity and 

scrubber water concentration would not 

have to be monitored). The maximum 

value for surface tension may be 

determined by the owner or operator 

during the initial performance test, or 

the owner or operator may adhere to the 

surface tension limits set by this 

standard. (If the surface tension limits 

set by this standard are used fo indicate 

compliance, an initial performance test 

would not be required.) The owner or 

operator would be required to measure 

and record the surface tension of the 

bath using a stalagmometer or a 

tensiometer at least once every 4 hours 

during operation of the tank. Operation 

of the electroplating tank at surface 

tensions above the acceptable value 

would constitute noncompliance with 

the standard. 

An owner or operator of a tank that 

uses a wefting-agent-fype fume 

suppressant or a combination wettingagent/foam-blanket-type suppressant fo 

comply with the standard would be 

required fo measure and record the 
65774 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

P.9 

surface tension ofthe bath using a 

stalagmometer or a tensiometer at least 

once every 4 hours during operation of 

the tank. Operation ofthe electroplating 

tank at surface tensions above the 

acceptable value would constitute 

noncompUance with the standard. 

An owner or operator of a tank that 

uses a foam blanket alone to comply 

with the standard would be required to 

conduct an initial performance test to 

confirm that the emission Umit of 0.003 

mg/dscm (1.3x10-6 gr/dscf) is being 

met. For ongoing compUance, the owner 

or operator would be required to 

maintain the foam blanket thickness at 

2.5 centimeters (cm) (1 inch (in.)), and 

measure and record the foam blanket 

thickness at least once every hour 

during operation ofthe tank. Operation 

of the electroplating tank at a foam 

blanket thickness below the acceptable 

value would constitute noncompUance 

with the standard. 

An owner or operator of a trivalent 

chromium electroplating tank would be 

required by the standard to monitor die 

surface tension using a stalagmometer or 

tensiometer every 4 hours. Operation of 

the electroplating tank at surface 

tensions above the acceptable value 

would constitute noncompUance with 

the standard. 

2. Operation and Maintenance 

Monitoring 

To ensure proper operation of the air 

poUution control device, the proposed 

standards require the owner or operator 

to prepare an operation and 

maintenance plan for the device. The 

plan would be incorporated into the 

startup, shutdown, malfunction plan 

required by § 63.6(e),* and would 

include a standardized checklist to 

document the operation and 

maintenance ofthe equipment, a 

systematic procedure for identifying 

malfunctions and for reporting them to 

supervisory personnel, and procedures 

to be followed to ensure that equipment 

or process malfunctions due to poor 

maintenance or other preventable 

conditions do not occur. 

As an indication of good maintenance 

procedures, the owner or operator 

would be required to record once each 

day the performance of washdown of 

the packed bed or mesh pad and to 

measure and record the pressure drop 

across the device. As with the gas 

velocity, the acceptable pressure drop 

range would be estabUshed by the 

owner or operator during the initial 

performance test. Unlike gas velocity 

and scrubber water concentration, die 

pressure drop readings would be used 

only as an indication of adherence to 

the operation and maintenance plan. 

Operation outside ofthe pre-established 

pressure drop range would not alone 

indicate noncompliance with the 

emission Umit. 

F. Reporting and Recordkeeping 

Requirements 

The owner or operator of any tank 

subject to these standards would be 

required to fulfill the reporting and 

recordkeeping requirements outlined in 

§ 63.10(e)(3)(v).s These requirements 

include those associated with startup, 

shutdown, or malfunctions; operation 

and maintenance records; compUance 

monitoring system records; performance 

test reporting; quarterly reports of no 

excess emissions for a year and semiannual reporting subsequently, if there 

are no excess emissions; and quarterly 

reports of exceedances ofthe emission 

limits. The owner or operator of any 

tank subject to these standards would be 

required to submit quarterly reports of 

any exceedances of monitored operating 

parameter values required under this 

subpart. These quarterly reports must 

contain the monitored operating 

parameter value readings for the periods 

constituting exceedances, and a 

description and timing of steps taken to 

address the cause ofthe exceedances. 

In addition to the above requirements, 

the owner or operator of a tank that uses 

an add-on air poUution control device to 

meet an emission standard would also 

be required to maintain records of daily 

and monthly inspections, daily gas 

velocity readings, daily washdowns, 

daily pressure drop readings, and any 

emission tests at the faciUty. FaciUties 

using packed-bed scrubbers to comply 

with tne standards would also be 

required to maintain records of daily 

scrubber water concentrations. All 

records must be maintained for a 

minimum of 5 years. Each inspection 

record would identify the device 

inspected and include the following (see 

further discussion in section VII): the 

date and approximate time of 

inspection, a brief description of the 

working condition of the device during 

the inspection, the gas velocity, the 

scrubber water concentration (if 

appUcable), the pressure drop, and any 

actions taken to correct deficiencies 

found during the inspection. Each 

record of washdown would identify the 

device and include the date, 

approximate time, and duration ofthe 

washdown. 

An owner or operator of a tank that 

uses a fume suppressant or foam blanket 

to comply with the standard would be 

•Ibid. • Ibid. 

required to maintain the following 

records at the faciUty for at least 5 years: 

the amounts of fume suppressants 

purchased (invoices); the surface 

tension or foam blanket thickness 

measurements; the frequency of 

maintenance additions; the amount of 

material added during each 

maintenance addition; the surface 

tension ofthe bath; measurements of 

foam blanket thickness; and any 

emission tests to assure compUance 

with the standard. Each record of a 

surface tension measurement would 

identify the tank and include the date, 

approximate time, measured surface. 

tension, and whether any additions 

were made to the bath. Each record of 

a foam blanket thickness measurement 

would identify the tank and include the 

date, approximate time, measured 

thickness, and whether any additions 

were made to the bath. If an addition 

was made, the amount of material added 

would also be recorded. 

An owner or operator of a tank that 

uses a trivalent chromium electroplating 

process would be required to maintain 

at the faciUty for at least 5 years records 

ofthe surface tension measurements; 

the amount of bath additive (containing 

fume suppressant) that is purchased 

(invoices); and any emission tests 

conducted. Each record of a surface 

tension measurement would identify the 

tank and include the date, approximate 

time, and measured surface tension. 

IV. Impacts ofthe Standards 

The nationwide impacts presented 

below are the impacts the proposed 

standards would have on existing 

faciUties in each category or subcategory 

identified. No net growth is projected 

for the source categories covered by 

these standards although new facilities 

may be constructed to replace existing, 

obsolete faciUties. Because no 

information is available for projecting 

numbers of new faciUties or 

electroplating tanks, nationwide 

impacts beyond baseline are presented 

here for existing faciUties only. For 

informational purposes, model plant 

impacts are presented for new faciUties 

in section VI.C.4. More detailed 

discussion on how these impacts were 

calculated can be found in section V.I.C 

of this preamble, Chapters 6 through 8 

of the BID, and in the New Technology 

Document (see ADDRESSES section). 

A. Hard Chromium Electroplating Tanks 

Existing hard chromium 

electroplating tanks at facilities with 

maximum cumulative potential rectifier 

capacities greater than or equal to 60 

miltion Ah/yr (large faciUties) would be 

required to meet a total chromium 
P.10 

teif / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

emission Umit of 0.013 mg/dscm 

(5.7xl0-a gr/dscf), which is based on 

the appUcation of composite mesh pads. 

The aggregated nationwide emission 

reduction from baseline which would be 

achieved by these sources would be 

approximately 126 megagrams per year 

(Mg/yr) (139 tons per year (tons/yr)). 

Nationwide aggregated annual costs 

beyond baseline would be 

approTximafely $17 milUon. 

Existing hard chromium 

electroplating tanks at faciUties with 

maximum cumulative potential rectifier 

capacities less than 60 million Ah/yr 

(small facilities) would be required fo 

meet a total chromium emission Umit of 

0.03 mg/dscm (1.3xl0-3 gr/dscf), which 

is based on the appUcation of packedbed scrubbers. The aggregated 

nationwide emission reduction from 

baseline which would be achieved by 

these sources would be approximately 

18 Mg/yr (20 tons/yr). Nationwide 

aggregated annual costs beyond baseline 

would be approximately $5 milUon. 

The total emission reduction for the 

hard chromium electroplating source 

category would be 144 Mg/yr (159 tons/ 

yr) with an associated total annual cost 

for control of $22 milUon. The total 

annual reporting and recordkeeping 

costs ofthe proposed standards would 

be approximately $8.6 milUon. 

The annual cost for control would 

increase the electroplating cost for hardchromium-plated products. It is 

assumed that the majority of these costs 

can be passed on fo the customer 

because the capital investment the 

customer has in the part, in most cases, 

far outweighs the increased 

electroplating cost. In addition, the 

actual product price increase resulting 

from compUance with the emission 

standard would be less than 1 percent 

of the current product price. The 

relatively minor effect on end product 

price results because, most often, hard 

chromium electroplating is not 

performed on an entire end product. 

Instead, electroplating is performed on 

components (e.g., hydraulic cylinders) 

ofthe end product (e.g., backhoe), and 

the cost increase for this service (that 

would result from compUance with the 

standard) is small compared to the price 

ofthe end product. It is conservatively 

estimated that fewer than 30 facilities 

with hard chromium electroplating 

tanks, or less than 2 percent ofthe 

industry (largely those that are presently 

uncontrolled), would close because of 

their inability to absorb the cost of 

meeting the standard. 

The nationwide aggregate energy 

impact (mainly for additional fan 

horsepower) beyond baseline would be 

approximately 102,900 megawatt hours 

per year (MWh/yr) for large faciUties 

and 6,300 MWh/yr for smaU faciUties. 

The nationwide soUd waste impact 

beyond baseUne from the periodic 

disposal of packing material would be 

130 cubic meters per year (ms/yr) (4,590 

cubic feet per year (ft'/yr)) for large 

faciUties and 26 ms/yr (910 fts/yr) for 

small faciUties. 

The use of composite mesh-pads and 

packed-bed scrubbers results in the 

generation of wastewater requiring 

reuse, treatment, or disposal. However, 

it is assumed that all wastewater would 

eventually be drained fo the 

electroplating tanks to make up for 

evaporative losses, as is the current 

industry practice. Thus, no wastewater 

impacts would be associated with this 

standard. If, for some reason, the 

wastewater were not recycled, it would 

need to be treated and disposed of in 

accordance with requirements under the 

Resource Conservation and Recovery 

Act. 

B. Decorative Chromium Electroplating 

Tanks 

Existing decorative chromium 

electroplating tanks using a chromic 

acid bath would be required fo meet a 

total chromiiun emission limit of 0.003 

mg/dscm (1.3xl0-o gr/dscf) if an air 

poUution control device is the sole 

means of controlling emissions or use 

wetting-agent-type fume suppressants 

and maintain a surface tension of less 

than 40 dynes/cm (2.7x10-3 lbf/ft). 

Impacts are estimated based on the use 

of chemical fume suppressants. The 

aggregate nationwide impact of the 

standards on decorative chromium 

electroplaters using chromic acid baths 

is estimated to be 10 Mg/yr (11 tons/yr) 

in emission reductions. No additional 

cost of control beyond that incurred at 

baseline would accrue because there are 

no capital costs associated with 

chemical fume suppressants. (The costs 

projected for baseline conditions result 

from the assumption that 42 percent of 

the faciUties will elect fo use packedbed scrubbers in conjunction with fume 

suppressants.) (See further discussion in 

section VI.C.) Tiie total annual reporting 

and recordkeeping costs of the proposed 

standards would be approximately $14 

milUon. No closures are anticipated as 

a result of compUance because there is 

no additional cost of control. No energy 

or solid waste impacts are attributable to 

the use of chemical fume suppressants. 

There are no control requirements in 

this proposed rulemaking for existing 

decorative chromium electroplating 

tanks using a trivalent chromium 

electroplating process. Therefore, there 

are no cost, economic, energy, or soUd 

waste impacts. These faciUties would be 

required to maintain a surface tension of 

the electroplating bath of 55 dynes/cm 

(3.8x10-3 lbf/ft) or to meet a total 

chromium emission Umit of 0.048 mg/ 

dscm (2.1xl0-s gr/dscf). The total 

annual reporting and recordkeeping 

costs ofthe proposed standards would 

be approximately $1.6 milUon. 

C. Chromium Anodizing Tanks 

Existing chromium anodizing tanks 

would be required fo meet an emission 

Umit of 0.003 mg/dscm (1.3xlO-Q gr/ 

dscf) or maintain a surface tension of 

less than 40 dynes/cm (2.7x10-3 lbf/ft). 

This is based on the use of chemical 

fume suppressants. The nationwide 

aggregate emission reduction beyond 

baseline would be 4 Mg/yr (4.4 tons/yr). 

As with decorative chromium 

electroplating facilities using a chromic 

acid electroplating process, there would 

be no nationwide cost impact beyond 

baseline. No closures are anticipated as 

a result of compUance with the 

proposed standards because there is no 

additional cost of control. There are also 

no energy or soUd waste impacts 

attributable to the use of chemical fume 

suppressants. The total annual reporting 

and recordkeeping costs of the proposed 

standards would be approximately $3.8 

million. 

V. Process Description and Description 

of Control Technologies 

This section describes the chromium 

electroplating and anodizing processes 

and the technologies that can be used to 

control chromium emissions from these 

processes. This section is provided to 

supplement.the rationale for selection of 

the proposed standards presented in 

section VI. For more detailed process 

and control technology descriptions, 

consult the BID for the proposed 

standards (see ADDRESSES) and the New 

Technology Document (see ADDRESSES). 

A. Process Descriptions 

The source categories that would be 

regulated by this standard are those 

performing hard chromium ° 

electroplating, decorative chromium 

electroplating, and chromium 

anodizing. (Area and major sources of 

each would be regulated for a total of six 

source categories.) The specific 

emission sources that would be 

regulated are the electroplating and 

anodizing tanks. Three distinct 

processes can be performed in these 

tanks: chromic acid electroplating, 

trivalent chromium electroplating, and 

chromium anodizing. Each process is 

described below. 
65776 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

p.11 

1. Chromic Acid Electroplating 

Chromic acid electroplating is the 

most widely used procedure for 

depositing chromium on metal. 

Chromium anhydride (CrOa), commonly 

referred to in the industry as chromic 

acid, is the hexavalent chromium 

compound used to formulate the 

electroplating bath. Chromic acid 

electroplating baths typically contain 

approximately 240 g/L (32 oz/gal) of 

chromic acid and 2.4 g/L (p.32 oz/gal) 

of sulfuric acid, which acts as a bath 

catalyst. 

Emissions of hexavalent chromium 

from the electrodeposition of chromium 

in chromic add electroplating baths 

occur primarily because ofthe 

inefficiency of the chromic add 

electroplating process. Eighty to 90 

percent ofthe electrical current appUed 

is consumed by the evolution of oxygen 

and hydrogen gases at the electrodes. As 

the bubbles burst at the surface of the 

electroplating solution, a fine chromic 

acid mist is formed. The rate of mist 

formation is a function ofthe chemical 

or electrochemical activity in the tank 

and increases directly with the amount 

of current (amperage) appUed to the 

tank, which is determined by the 

amount and type of parts plated or 

surface area plated in the tank and the 

current densities needed to effectively 

plate the parts. 

In hard chromium electroplating, a 

relatively thick layer of chromium is 

deposited directly on a base metal 

(usually steel) to provide functional or 

engineering characteristics such as 

hardness, a low coeffident of friction, 

and wear and corrosion resistance. Hard 

chromium electroplating is used for 

items such as hydrauUc cylinders and 

rods, industrial rolls, zinc die castings, 

plastic molds, engine components, and 

marine hardware. Current densities for 

hard chromium electroplating tanks 

range from 1,600 to 6,500 amperes per 

square meter of surface area plated (A/ 

m

2

) (150 to 600 amperes per square foot 

[A/ft2]). Electroplating times range from 

one-half hour to 36 hours, and 

electroplating thicknesses range from a 

few to several hundred microns dan). 

In decorative chromium 

electroplating, the base material (e.g., 

brass, steel, aluminum, or plastic) 

generally is plated with layers of copper 

and nickel followed by a relatively thin 

layer of chromium to provide a bright 

surface with wear and tarnish 

resistance. Decorative chromium 

electroplating is used for items such as 

automotive trim, metal furniture, 

bicydes, hand tools, and plumbing 

fixtures. Current densities for decorative 

chromium electroplating tanks range 

from 540 to 2,400 A/m2 of surface area 

plated (50 to 220 A/ft2). Electroplating 

times range from less than 1 minute to 

5 minutes, and electroplating 

thicknesses range from 0.003 to 2.5 (im 

(0.0001 to 0.1 mil). 

Hard chromium electroplating tanks 

emit significantly more chromic acid 

emissions than decorative chromium 

electroplating tanks because ofthe 

higher current densities and longer 

electroplating times required to achieve 

the desired plate thickness. Emissions 

from both hard chromium and 

decorative chromium electroplating are 

comprised almost entirely of hexavalent 

chromium because a chromic add 

electroplating process is used. 

2. Trivalent Chromium Electroplating 

Trivalent chromium processes are 

used at less than 10 percent of the 2,800 

fadUties with decorative chromium 

electroplating tanks. This process is not 

used for hard chromium electroplating 

because the trivalent chromium process, 

as currently formulated, cannot achieve 

the fuU range of plate thicknesses 

necessary for most hard chromium 

electroplating appUcations. 

Trivalent chromium processes are 

appUcable for the full range of 

decorative chromium electroplating 

appUcations. However, because the 

process is relatively new, it does not 

have widespread use. Also, spedal 

precautions must be taken when a 

trivalent chromium process is used for 

electroplating brass, zinc, and tubular 

(hollow) steel parts. If there is 

insuffident coverage of nickel on the 

part, the exposed base metals may 

dissolve in the trivalent chromium 

electroplating solution, resulting in 

contamination of the bath. 

Contamination problems can be 

overcome through the appUcation of a 

thicker layer of nickel, the use of ion 

exchange columns to purify the bath, 

and several other methods. At present, 

there are several trivalent chromium 

tanks at which these types of parts are 

successfully plated. 

Two types of trivalent chromium 

processes are commercially available: 

The single-cell and the double-cell. The 

single-ceU process is a halogen-based 

system using graphite anodes and 

additives to prevent oxidation of 

trivalent chromium at the anode. In this 

system, the anodes are in direct contact 

with the electroplating solution. The 

double-ceU process is a sulfate-based 

system in which lead anodes are 

encased in boxes that are lined with a 

permeable (ion-selective) membrane and 

that contain a dilute solution of sulfuric 

add. This system eliminates contact and 

oxidation of the trivalent chromium 

electrolyte at the anode. The double-cell 

process requires fewer additives. 

The main difference between the 

trivalent chromium processes and 

chromic add electroplating processes is 

in the chromiiun electroplating step. 

The electroplating bath chemistry is 

different for trivalent baths; the bath is 

comprised mostly of trivalent chromium 

with hexavalent chromium considered 

as a bath contaminant. Trivalent 

chromium electroplating solutions 

typically contain between 22 to 30 g/L 

(3 to 4 oz/gal) of trivalent chromium. 

The exact compositions of trivalent 

chromium electroplating solutions are 

proprietary. The process lines for 

trivalent chromium electroplating -

processes also differ from those used 

with a chromic add electroplating bath. 

For example, additional rinse tanks or 

post dips are added to the electroplating 

line in the trivalent chromium 

electroplating processes. 

Tests indicate tiiat emissions from 

trivalent chromium tanks have total 

chromium concentrations of 0.048 mg/ 

dscm (2.1x10-5 gr/dscf) and hexavalent 

chromium emissions of 0.004 mg/dscm 

(1.75x10-6 gr/dscf). Additional 

advantages of using a trivalent 

chromium bath, from a pollution 

prevention standpoint, are discussed in 

section V.B.5. 

3. Chromium Anodizing 

In the chromium anodizing process, 

chromic add is used to form an oxide 

layer on aluminum that provides 

corrosion resistance. The chromium 

anodizing process is used primarily to 

coat aircraft parts and architectural 

structures that are subject to high stress 

and corrosive conditions. The 

Department of Defense (Naval Air 

Systems Command) is conducting 

research on alternatives to chromic add 

anodizing for miUtary aircraft. This 

research focuses on the use of a sulfuric/ 

boric acid anodizing process. If the 

research results impact the current 

rulemaking, they will be made available 

for comment. 

The chromic add concentration in 

anodizing baths is approximately 50 to 

100 g/L (7 to 13 oz/gal). The current 

densities appUed range from 1,550 to 

7,750 A/mi (144 to 720 A/ft?) of surface 

area anodized. The anodizing time 

ranges from one-half to 1 hour. The 

anodizing process is a voltagecontrolled process. Voltage is appUed 

step-wise (in 5 V increments per 

minute) from 0 to 20 or 40 V and 

maintained at the desired voltage for the 

remainder of the anodizing period. 

When current is appUed, chromic add 

breaks down in die anodizing bath 

resulting in the Uberation of oxygen and 
P.12 

Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 65777 

hydrogen. The oxygen evolves at the 

surface of the aluminum part where it 

reacts with the substrate to form an 

aluminum oxide layer. At the same 

time, chromic and dichromic acids 

contained in the bath react with the 

aluminum oxide film in a dissolving 

action, which results in the formation of 

very fine pores that enhance Ae 

continuation of current flow to the 

metal surface. About half of the 

oxidized aluminum is retained as 

anodic film, and the remainder goes into 

solution to form alumina-chromic add 

compounds. The liberation of hydrogen 

and oxygen gas results in the formation 

of a fine chromic add mist at the surface 

of the anodizing solution. Misting is 

more pronounced at the beginning of 

the anodizing cycle when there is 

minimal resistance to current flow. As 

the oxide film develops on the surface 

of the part, the resistance to current flow 

is higher, and less mist is formed. 

B. Description of Control Techniques 

This section presents descriptions of 

the techniques typically used to control 

emissions of chromic add mist from 

chromium electroplating and anodizing 

tanks. All of these control technologies 

are effective regardless ofthe size of the 

operation. In particular, the use of a 

given technology is not a function of 

whether a source is considered major or 

area. A more complete description of 

these control technologies is presented 

in the BID for the proposed standards 

(see ADDRESSES) and in the New 

Technology Report (see ADDRESSES) 

Control technologies (e.g., chevronblade mist eliminators) that were 

considered less stringent than tiie 

MACT floor are not included in the 

following discussion. However, 

information on less-stringent control 

technologies is presented in the BID for 

theproposed standards. 

The discussions below present 

information concerning the achievable 

emission levels and percent reductions 

(effidencie.) for the various 

demonstrated control measures. Percent 

reduction provides a convenient basis 

on which to compare various control 

techniques. Percent reduction is 

determined from the control device inlet 

and outlet mass emission rates. 

However, the available test data strongly 

indicate that outlet chromium 

concentrations within each class of 

control device type are relatively 

constant and are not influenced by the 

inlet chromium concentration to the 

control device. Thus, the "control 

efficiency" actually achieved by a given 

control device would vary depending on 

inlet loading. For this reason, the level 

of control assigned to each control 

technique in the discussion below is 

based on the percent reduction 

achievable by well-maintained units at 

representative inlet loadings (refer to 

chapters 4 and 5 of the BID) and is used 

here only for the purpose of estimating 

emission reduction impacts assodatea 

with alternative control techniques. 

1. Packed-Bed Scrubbers 

Packed-bed scrubbers are typically 

used by hard and decorative chromium 

electroplating and chromic add 

anodizing tanks to control emissions of 

chromic acid mist. Both single and 

double packed-bed designs are used. 

Chromic add mist is removed from the 

gas stream primarily by impaction of 

droplets on packing media. 

First, the gas stream is wetted by 

spraying water countercurrent to the gas 

flow to enlarge the droplet size. The gas 

stream then passes through the packed 

bed(s) where the droplets impinge on 

the packing media. Ine packing media 

used to control chromic add mist 

typically are made of polypropylene and 

are configured to have a high surfacearea-to-volume ratio. Packing depth is 

typically about 0.3 to 0.6 m (1 to 2 ft). 

In most cases, the packed-bed section of 

the scrubber Is followed by a mist 

eliminator section comprised of a single 

chevron-blade mist eliminator. The mist 

eliminator removes any water entrained 

from the packed-bed section. Treated 

gases then pass through an induced 

draft fan and out a stack or exhaust vent. 

The scrubber water is usually 

recirculated and periodically tapped 

and discharged to the electroplating 

tanks as makeup solution. 

The operating parameters that most 

greatly affect the performance of 

packed-bed scrubbers include the gas 

velodty entering the packed bed and the 

liquid-to-gas ratio. Removal of chromic 

acid mist is accomplished by reducing 

the velodty of the gas stream in an 

expansion chamber at the inlet ofthe 

scrubber. The velodty must be 

maintained at a rate such that the 

droplets possess suffident energy to 

collide with the packing media. 

Operation of packed-bed units at greater 

than the design gas velodty will 

decrease gravitational settling of 

chromic add droplets upstream ofthe 

packed bed. An increase of the gas 

velodty above optimal levels will also 

cause reentrainment of chromic add 

droplets from the packed bed and 

contribute to an overall decrease in 

collection effidency. If the liquid-to-gas 

ratio is too high, tha packed bed will 

become flooded and the gas flow will be 

restricted. A liquid-to-gas ratio that is 

too low will result in insuffident 

wetting ofthe packed bed, leaving 

portions ofthe bed dry. This inhil 

interception of particles by the fluid 

boundaries on the packing mater 

Also, the inlet gas stream will not be 

wetted enough to allow enlargement of 

the chromic add droplets. Therefore, a 

liquid-to-gas ratio that is too low will 

result in lower collection efficien' 

Other factors that affect performance 

include the surface contact area and 

distribution of the packing media 

Inadequate surface contact area results 

in leas impingement and, thus, less 

removal of chromic add m 

Nonuniform distribution or Bottling of 

the packing media in its frame results in 

channeling or bypass, which adverse 

affects scrubber performance. Also, 

plugging of the spray nozzles used for 

packing media washdown can result 

excessive buildup i d on 

the packing media leading to 

reentrainment or plugging of the bed. 

Two independent studies were 

conducted by the Agency to determine 

the effects of: (1) Chromic add 

concentrations in the scrubber v» 

and (2) overhead washdown on scrubber 

performance. The results of the 

rediculation study indicate that the 

chromic acid concentration of the 

scrubber water does not significantly 

affect scrubber performance. However, a 

slight increase in emissions was noted 

at scrubber water concentrations above 

45 g/L (6 oz/aal). Therefore, the Agoi 

is requiring mat chromic add 

concentrations in tiie scrubber be 

maintained below 45 g/L (6 ox;, 

Most plants typically have scrubber 

water concentrations less than 15 g/L (2 

oz/gal). Results from the washdown 

study indicated that periodic flooding of 

the packed bed with clean water helps 

to clean packing media and prev 

degradation in the performance of the 

unit. However, continuous wash' 

of the packing media does not 

significantly improve ; 

beyond that achieved v 

washdown. Emission tast res i iSO 

suggest that double packed-bed designs 

do not improve the performance level 

beyond that achieved with single 

packed-bed designs. The EPA n 

comments on the appropriateness of the 

scrubber water concentration value or 

any data to indicate the significance of 

increase in chromium emissions relative 

to the scrubber water concentration. 

As discussed previously, the i: 

loading to packed-bed scrubbers does 

not affect the outlet concentration 

achieved; therefore, the percent 

reduction achieved by the control 

device is dependent upon the fan 

concentration level. Hard chromium 

electroplating tanks typically have high 

inlet concentrations (above 
P.13 

65778 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

approximately 3 mg/dscm [0.001 gr/ 

dscf]). Decorative chromium 

electroplating and anodizing tanks, 

which operate with lower current 

densities, produce lower emissions, 

about one-third diat encountered at 

representative hard chromium 

electroplating tanks. 

Control device vendors estimate that 

removal efficiencies for packed-bed 

scrubbers range from 95 to 99 percent. 

The control efficiencies achieved by 

existing chromium electroplating and 

anodizing tanks using packed-bed 

scrubbers are often on the low end of 

this range because of die less-thanoptimum operating and maintenance 

practices prevalent in die industry. 

Based on data obtained during EPA's 

emission test program, packed-bed 

scrubbers with periodic washdown can 

achieve outlet hexavalent chromium 

concentrations of 0.03 mg/dscm 

(1.3x10-* gr/dscf). Assuming 

performance ofthe control device at 

proper conditions, a 99 percent control 

efficiency for packed-bed scrubbers is 

achievable at die higher inlet 

concentrations typically found in hard 

chromium electroplating tanks; 97 

percent efficiency is achievable at the 

lower inlet concentrations found at 

decorative chromium electroplating and 

anodizing tanks. 

Operating costs for packed-bed 

scrubbers depend on unit size. The size 

is a function of the airflow rate, which 

is determined by die surface area and 

configuration ofthe electroplating or 

anodizing tank(s). 

2. Composite Mesh-Pads 

Composite mesh-pads consist of 

layers of interlocked fibers densely 

packed between two supporting grids. 

The composite mesh pad was developed 

to remove small particles (<5 nm [0.2 

mils]) diat were not effectively 

controlled by conventional 

technologies. The layers of material in 

composite pads are arranged with die 

smallest diameter fiber layer located in 

the center ofthe pad and progressively 

larger diameter layers located on both 

sides of die center. The fiber diameters 

used in these pads range from 0.005 to 

0.08 cm [2 to 32 mils]). Particles larger 

than 1 nm (0.025 mil), traveling with 

sufficient velocity, collide widi die 

fibers in the first portion of die pad and 

adhere to their surfaces. These captured 

particles coalesce into larger droplets as 

they travel through die small-diameter 

fiber layers in the center of the pad. 

These enrarged particles either drain to 

the bottom of die unit or are reentrained 

in the gas stream. The reentrained 

particles are then captured by the largediameter fiber layers in the back of the 

pad. 

Factors that affect die performance of 

mesh-pad mist eliminators include the 

pad cleaning frequency, die velocity of 

the gas stream, and die particle size of 

the entrained pollutant. Pad cleaning 

frequency is related to the tendency of 

mesh pads to plug if chromic acid is 

allowed to build up on die pad material. 

The mesh pads should be washed down 

with water at least daily to reduce the 

chance of plugging. 

Gas stream velocity and particle size 

affect performance because as velocity 

increases, collection of particles through 

the mechanism of inertial impaction, 

increases. Thus, gas velocities that are 

too low can result in reduced 

performance. However, gas velocities 

that are too high also can reduce 

performance because particles may 

become reentrained in die gas stream. 

Based on emission test results, a 

composite mesh-pad system can achieve 

outiet hexavalent chromium 

concentrations of 0.013 mg/dscm 

(5.7x10 -- gr/dscf). At representative 

inlet loadings, the percent reduction 

achieved by a composite mesh-pad 

system is greater than 99.5 percent at 

the higher inlet loadings typical for a 

hard chromium electroplating 

operation. 

Operating costs for composite meshpad systems depend on die size and die 

type of control equipment that is used 

in conjunction with die composite pads 

(e.g., packed-bed scrubbers or a series of 

mesh pads). The size ofthe unit is a 

function ofthe airflow rate, which is 

determined by the surface area and 

configuration ofthe electroplating or 

anodizing tank(s). 

3. Fiber-Bed Mist Eliminators 

Fiber-bed mist eliminators have been 

used predominantly to control acid 

mists from sulfuric, phosphoric, and 

nitric acid plants. One system, however, 

is known to be in place to control 

chromium emissions from electroplating 

tanks. Fiber-bed mist eliminators 

remove contaminants from a gas stream 

through die mechanisms of inertial 

impaction and Brownian diffusion. 

Fiber-bed mist eliminators that are 

designed based on inertial impaction as 

die principal control mechanism are 

more efficient than odier control devices 

that use this mechanism (e.g., packedbed scrubbers) because ofthe higher 

surface area-to-volume ratios. These 

higher ratios result in greater 

obstruction of the gas flow, which 

provides additional opportunities for 

impaction. Fiber beds designed for 

contaminant removal by Brownian 

diffusion as well as inertial impaction 

are the most efficient mist eliminators 

currently available. These units are 

typically installed downstream of an 

existing control system. Fiber-bed mist 

eliminators are not recommended as the 

first stage of a control system because of 

their tendency to plug. An existing 

control system, such as mesh pads or a • 

packed-bed scrubber, should precede 

the fiber-bed mist eliminator to remove 

the majority ofthe emissions and thus 

prevent plugging of the fiber bed. 

Fiber-bed mist eliminators typically 

consist of one or more fiber beds. Each 

bed consists of a hollow cylinder 

formed from two concentric Screens 

attached to a top flange and a bottom 

drain plate (fiber cage). The fiber packed 

into the annular space between the two 

screens forms a bed widi a radial 

thickness of 5 to 8 centimeters (cm) (2 

to 3 inches (in.)). The cages are typically 

fabricated from either metal- or 

fiberglass-reinforced plastic. The fibers 

are fabricated from glass, ceramic, 

plastic, or metal in bulk (loose) or 

roving (rope) form. The individual fibers 

are usually less than 25 um (1 mil) in 

diameter. 

A typical impaction cylinder has an 

outside screen diameter of 66 cm (26 

in.), a bed thickness of 5 cm (2 in.), and 

an overall length of 180 cm (72 in.). 

Pressure drops for impaction units range 

from 0.12 to 2.0 kiloPascals (kPa) (0.5 to 

8 inches of water column [in. w.c.]). 

Fiber-bed mist eliminators are also 

equipped with two spray nozzles. One 

nozzle is located at the top of the unit 

and is used to wash down any large 

particles that may clog die mist 

eliminator. The other nozzle is located 

at the bottom of the unit and is used as 

an aerosol spray to remove any 

contaminants in the mist eliminator that 

may cause plugging or improper 

drainage. 

Fiber-bed units are designed for 

horizontal, concurrent gas-liquid flow 

dirough Uie bed. The contaminated gas 

stream and water flow to the 

downstream face of die bed, and tiie 

acid mist in the gas stream impacts on 

the surface ofthe fibers and drains 

down the outer face of the bed to the 

sump, while the cleaned gas flows up 

and out the top of the unit. 

The major factors affecting the 

performance of the fiber-bed mist 

eliminator are the gas velocity and 

pressure drop. As with mesh-pad mist 

eliminators, gas flow rates with 

impaction-type, fiber-bed units must be 

maintained above a certain lower limit 

because ofthe decrease in efficiency of 

inertial impaction at low flow rates. The 

maximum gas flow rate in fiber-bed mist 

eliminators is limited by either: (1) A 

decrease in efficiency with increasing 
Pssfasl RjTsgsste / Vol. 58, No. % _0 7~TJi-_-sday, December 16, 1993 / Propossd Stiles {53779 

P.14 

gas flow rate or (2) a.gas-phasa pressure 

drop Mmitatron. 

- Fiber-bed mist eliminators, using 

impaction-type cylinders, have recently 

been employed at a Naval depot thatperforms chromium electroplating and 

anodizing. Prior to entering the fiberbed mist eliminators, each chromic add 

stream is controlled with a vertical-flow, 

.single packed-bed scrubber unit with 

chevron-blade mist eliminators 

preceding and following the scrubber. 

As previously discussed, this 

configuration is designed to prevent 

plugging of tho fiberbad unit. 

Emissions test results on fiber-bed 

mist eliminators suggest that these 

systems are capable of achieving outlet 

total chromium concentrations of 

1.0xl0-« mg/dscm (4.4xl0-s gr/dscf) 

with corresponding removal efficiencies 

greater than 99.9 percent. 

Operating costs for fiber-bed mist 

eliminators depend on tha size and the 

design pressure drop. The size ofthe 

unit is a function ofthe airflow rate, 

which is determined by the surface area 

and configuration ofthe electroplating . 

or anodizing tank(s). The design 

pressure drop is a function ofthe 

density of the fiber bed. The higher the 

bed density, ihe higher the pressure 

drop. Net annualized costs for fiber-bed 

mist eliminators are approximately 200 

percent higher than the costs for single 

packed-bed scrubbers at both new and 

existing facilities, and approximately 90 

percent higher than composite meshpad systems. These costs account for the 

additional control device, such as a 

packed-bed scrubber, that is required 

prior to the fiber-bed mist eliminator fo 

prevent plugging. The only fiber-bed 

mist eliminator system known to be 

controlling chromic acid emissions from 

electroplating tanks is located af a 

government, not a commercial, facility, 

and is not considered a similar source. 

Because of this fact and the high costs 

associated with this control device, EPA 

has determined that fiber-bed mist 

eliminators ara not MACT for new 

sources but ara considered an emerging 

technology for tha source categories 

being regulated. , 

4. Chemical Fume Suppressants 

•Chemical fume .suppressants are 

compound- that ara added directly to 

chromium -lecteoplatiEg and __odi_ing 

baths to reduce or inhibit misting. JFume 

suppressants include three types: 

wettimg agents, foam blanket-, and 

combinations that include both a 

wetting agent and a foam blanket 

Trivalent chromium electroplating 

solutions akoeanteLa wetting agents, in 

die trivateat chromium bsth.eowEfyTsr, M 

wetting tigaat is used to enhance tha 

uniformity of electroplating thickness, 

not as a &ma suppressant. Therefore, 

the following discussion of fume 

suppressants as a control technology is 

specific to hexavalent chromium baths. 

Information on trivalent chromium 

baths can be found in sections V.A.2 

and V.B.5. 

An important distinction between 

wetting agents and foam blankets is in 

the mechanism by which they reduce 

emissions. Wetting agents reduce or 

inhibit misting by lowering the surface 

tension of the electroplating or 

anodizing bath. When the surface 

tension of die solution is reduced, gases 

escape at the surface of the 

electroplating solution with less of a 

"bursting" effect, forming less mist. 

Fume suppressants that produce a foam 

blanket do not preclude the formation of 

chromic acid mist, but rathar trap the 

mist formed under a blanket of foam. 

Fume suppressants are used widely 

by decorative chromium electroplaters. 

Hard chromium platers seldom use 

fume suppressants because the wetting 

agents used aggravate pitting, which 

affects the quality of die hard chromium 

plate. Also, when foam blankets are 

used, there is a potential for explosion 

of die entrapped hydrogen gas. These 

tendencies are more pronounced in hard 

chromium electroplating than in 

decorative chromium electroplating 

because ofthe higher current densities, 

longer electroplating times, and thicker 

deposits associated with hard chromium 

electroplating tanks. 

a. Wetting Agesits. The most common 

types of wetting agents used are 

fluorinated wetting agents, which ara 

very stable throughout a wide range of 

operating temperatures, current 

densities, chromic acid concentrations, 

and oxidation-reduction reactions. A 

number of fume suppressant, 

formulates indicate that wetting agents 

diat are fhnorocarbon-based may 

aggravate pitting and defects in base 

metals when electroplating thickness 

exceeds 13 fo 25 p n (9.5 fo 1 mil). Some 

fume suppressant vendor literature 

recommends caution regarding use of 

these compounds as the chromium 

diickness increases beyocd 25 to IGO 

Um (1 to 4 mils) (-speeding on tie 

product). However, some 3m_n_f_cturers 

now state that certain base metals have 

a tendency to pit and that this tendency 

is mot aggravated by the w® of fume 

suppressant -additives. 

Cnromic add slsctrcpktiag baths 

typically-have a surface tension of about 

70 dynes/cm (4.8x13-3 lbf/ft). Ths 

addition cfa wetting agent can 

effectively lower the surface tension _f 

these betha to -about 40 dyass/cm 

(2.7x10 - s !V&). Further additions of 

the wetting agent will not lowar the 

surface tension of £_a elscfc?cpla_iTg 

solution appreciably beyond this point. 

Surface tensions between 30 to 40 

dynes/cm (2.0x10-3 to 2.7X10-- iVft) 

minimize chromic acid mist 7T?_ro._tian 

becausa the hydrogen amd oxygen gas 

bubbles generated during electroplating 

do not burst at the c_r3ac_ ofthe 

electroplating (__£_ ES Chay do at ii*5tsr 

bath surface tensions. 

The initial makeup volume) of wilting 

agents is determined by the volumo CT! 

electroplating or ancdiziag achitf an asd 

die temperature ofthe fccth. They oro 

depleted from electroplating izzd 

anodizing baths by drsge-t. Brag-tit is 

die solution carried out cf the 

electroplating or snoozing talk by pcrTiO 

as the parts are transferred bstwcsn 

tanks. Monitoring tha ourfaco tandaa cl 

die electroplating or oncdi_ir»3 b_t_ is 

die most effective matfcod fe? 

determining when to add wetting e^ect 

to the batii. The surface tsneica of ths 

bath can be determined by usiajj _3 

easy-to-use, relatively inexpaETJive 

device called a stalegmoraetar. 

b. Foam BlanketsTFoam blankets are 

formed by agitation produced by tho 

hydrogen and oxygen gas bubbles 

generated during electroplating. Once 

-formed, the foam blanket is usually 

maintained at a thickness of 1.3 to 2.5 

cm (0.5 to 1.0 in.) and covers the entire 

surface of uie electroplating bath. Foam 

blankets trap the hydrogen gas aad 

chromic acid mist in the foam layer. In 

order to maintain die dosired fcam 

thickness around ths cathode, a heavy 

foam layer can develop in other areas 

(comers) ofthe tank. Sn these heavy 

foam areas, hydrogen gases will build 

up and if a spark is generated (e.g., from 

die contacting equipment) a hydrogen 

explosion can occur. As a result of this 

explosion, the foam layer, aloritr, with a 

portion ofthe electroplating solution, is 

blown out of the tank, and the 

chromium plate on die part may be 

damaged. If the foam layer is not 

maintained at a minimum reasonable 

diickness, die ability ofthe foam layer 

to inhibit misting is reduced. 

Initial makeup volumes of foam 

blanket solutions are determined by the 

surface area of the electroplating bath, 

amount of current applied, and 

temperature and chromic acid 

concentration of the electroplating bath. 

Generally, the lower the temperature, 

die less product is needed. 

Foam blankets are depleted primarily 

by decomposition; however, dregout of 

the foam may also ba a factor. Also, 

foam blankets may be pulled into 

ventilation hoods if the solution level is 

too close to the hoods. Some types may 

also be depleted by excessive air 
65780 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

agitation of the bath. Appreciable 

concentrations of alkali metal ions, 

especially potassium, tend to reduce die 

solubility of some foam blankets. 

Visual monitoring of the diickness of 

the foam blanket is the most common 

..metiiod for determining when to add 

foam blanket solution to the bath. The 

frequency ofthe maintenance additions 

depends on the amount of work 

processed through the electroplating 

tank and the dragout rate of the 

solution. 

c. Combination Fume Suppressants. 

Combination fume suppressants 

(wetting agent plus a foam blanket) 

reduce die surface tension of the 

electroplating bath while forming a 

foam blanket over the surface. Because 

ofthe synergistic effects ofthe two 

components, less product is required 

than if either die wetting agent or die 

foam blanket were used alone. 

d. Factors Affecting Performance and 

Cost of Fume Suppressants. The main 

factor affecting the performance of 

chemical fume suppressants is die 

amount of fume suppressant present in 

the electroplating or anodizing bath. If 

insufficient wetting agent is present in 

the bath, die surface tension ofthe 

solution will not be maintained below 

40 dynes/cm (2.7x10-3 lbf/ft) and, 

therefore, the effectiveness of the 

wetting agent in inhibiting misting will 

be substantially reduced. If a foam 

blanket is used, proper care must be 

taken to maintain the foam blanket at 

the specified thickness because a thin 

foam layer will not entrap the chromic 

acid mist efficiently, and areas of heavy 

foam may cause a hydrogen gas buildup 

and explosion potential. 

Emission tests were conducted on a 

decorative chromium electroplating line 

with and without fume suppressants. 

Two types of fume suppressants were 

evaluated during die test program: (1) A 

foam blanket; and (2) a combination 

foam blanket and wetting agent. Test 

results indicate that fume suppressants 

are extremely effective in inhibiting the 

release of chromic acid mist. Hexavalent 

chromium concentrations range from 

0.001 to 0.007 mg/dscm (4.4x10-' to 

3.1x10-6 gr/dscf) when a foam blanket 

or a combination foam blanket and fume 

suppressant is used in the electroplating 

bath. The he:xavalent chromium 

concentrations measured when die 

combination foam blanket and wetting 

agent were used ranged from 0.001 to 

0.003 mg/dscm (4.4X10-? to 1.3xl0~« 

gr/dscf). These results indicated tiiat the 

combination fume suppressant might be 

marginally more effective than the foam 

blanket type suppressant. Both types of 

fume suppressants reduced chromium 

emissions by more than 99.5 percent 

compared to uncontrolled levels. 

The costs of using chemical fume 

suppressants depend upon the tank 

capacity, the amount of current applied, 

and the number of parts processed. 

5. Source Reduction and Recycling 

The Pollution Prevention Act of 1990 

establishes the following environmental 

management hierarchy as national 

policy: 

a. Pollution should be prevented or 

reduced at the source wherever feasible; 

b. Pollution that cannot be prevented 

should be recycled in an 

environmentally safe manner wherever 

feasible; 

c. Pollution that cannot be prevented 

or recyeled should be treated in an 

environmentally safe manner wherever 

feasible; and 

d. Disposal or otiier release into the 

environment should be employed only 

as a last resort and should be conducted 

in an environmentally safe manner. 

Although the Act does not specifically 

define "pollution prevention," it states 

that source reduction is fundamentally 

different and more desirable than waste 

management and pollution control. 

Source reduction is defined as any 

practice that reduces the amount of any 

hazardous substance entering the waste 

stream or otherwise released into the 

environment prior to recycling, 

treatment, or disposal. 

There are two source reduction 

alternatives available for decorative 

chromium electroplating tanks. The first 

involves the use of a trivalent chromium 

electroplating process instead of a 

chromic acid process. This alternative 

has two primary benefits. First, trivalent 

chromium may be less toxic than 

hexavalent chromium and is not 

presently classified as a known human 

carcinogen, as is he:xavalent chromium. 

A second benefit is that these processes 

also result in less total chromium in 

process wastewaters because of the 

lower total chromium concentrations in 

the electroplating baths as compared to 

chromic acid electroplating baths. The 

total chromium concentration of 

trivalent chromium solutions is 

approximately one-fifth that of 

hexavalent chromium solutions. In 

addition, less sludge is generated 

because ofthe lower total chromium 

content in the wastewater. As discussed 

in section VI.K. of this preamble, EPA 

specifically requests comment on 

whether the trivalent chromium 

electroplating process should be 

required for all new decorative 

chromium electroplaters. 

The addition of chemical fume 

suppressants is also considered to be a 

source reduction technique because 

fume suppressants inhibit emissions at 

the source. As mentioned previously, 

chemical fume suppressants are 

extremely effective (greater than 99.5 

percent) in reducing emissions from 

decorative chromium electroplating and 

anodizing tanks. 

In addition, each ofthe add-on 

pollution control techniques being 

considered for this source category has 

a recycling element; they allow for 

recycling of all collected chromium 

and/or reductions in the total 

wastewater treatment burden of a 

facility. All of the effluent generated 

from the control devices at hard 

chromium electroplating and anodizing 

tanks is recycled back to the 

electroplating tank to make up for 

evaporative losses. At decorative 

chromium electroplating tanks, where 

large quantities of rinse water are 

generated, scrubbers are often used as 

evaporators that reduce the total 

wastewater treatment burden by 

concentrating the process rinse waters 

prior to treatment. For this reason, a 

large majority of decorative chromium 

electroplaters continue to operate 

scrubbers in conjunction with fume 

suppressants. As discussed in section 

VI.K. of this preamble, EPA specifically 

requests comment on whether the final 

standards should require recycling of 

the wastewater. 

Unlike decorative chromium 

electroplating tanks, hard chromium 

electroplating tanks typically do not use 

fume suppressants either alone or in 

conjunction with an add-on control 

device. As discussed earlier, wetting 

agents can cause pitting in the hard 

chromium plate and, historically, foam 

blankets have been viewed as explosion 

hazards. However, EPA obtained data 

from a test at a hard chromium 

electroplating operation using a fume 

suppressant (a combination wetting 

agent/foam blanket) in conjunction with 

an add-on control device, a mesh-pad 

mist eliminator. The EPA also 

performed a test to measure emissions 

from a system involving the use of a 

foam blanket and polypropylene balls in 

conjunction with a packed-bed scrubber 

to control emissions at a hard chromium 

electroplating operation. These data 

indicate that chromium removal 

efficiencies averaged 97.7 percent when 

a foam blanket was used and only 60.1 

percent with the use of a combination 

fume suppressant. (These control 

efficiencies do not include control 

associated with the add-on control 

device, only the control associated with 

the foam blanket or fume suppressant. 

Outlet concentrations, considering 
P.16 

F__er_l Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules ©5781 

control, are provided in the paragraph 

below.) 

The significant difference in tiie 

performance ofthe foam blanket 

compared to that ofthe combination 

fume suppressant at the hard chromium 

electroplating tanks cannot be explained 

by information obtained af the time of 

testing. Possible explanations for this 

inconsistency include differences in the 

maintenance of foam blankets, 

characteristics ofthe parts being plated, 

and die transportation and handling of 

Ihe parts in the electroplating bath. The 

data do indicate that the use of foam 

blankets and combination fume 

suppressants in hard chromium 

electroplating tanks is less effective than 

the use of these compounds in 

decorative chromium electroplating 

tanks. 

The above tests also indicated that 

overall emissions from a fume 

suppressant or foam blanket/control 

device system were lower than emission 

rates achieved solely with a control 

device. The emissions from the fume 

suppressant/mist eliminator were 

measured as 0.008 mg/dscm (3.5x10-6 

gr/dscf), a 30 percent improvement in 

emission control over that obtained witii 

the mist eliminator system alone. 

Emissions from the foam blanket/ 

packed-bed scrubber system were also 

measured as 0.008 mg/dscm (3.5x10-« 

gr/dscf), ah 86 percent increase in 

emission control over that obtained with 

the packed-bed scrubber system alone. 

However, as previously stated, wetting 

agents can cause pitting in the hard 

chromium plate, and foam blankets 

have a potential explosion hazard. 

Therefore, the use of foam blankets and/ 

or wetting agents in conjunction with 

add-on control devices was not 

considered feasible for the entire range 

of hard chromium electroplating tanks 

and is not included as a regulatory 

alternative. This does not preclude the 

use of these methods by some faciUties, 

such as those tested, which may be able 

to comply with the standard by using 

wetting agents or foam blankets in 

conjunction with an add-on control 

device. 

VI. Rationaale fiwr Selection ofthe 

This section describes the rationale 

for the decisions made by the 

Administrator in selecting the proposed 

standards. 

A. Selection of Pollutant and Source 

Categories To Be Regulated 

Section 112 requires EfA fo estabhsh 

national standards fo reduce HAP 

emissions from source categories that 

emit these pollutants. Section 112(b) 

provides a list of 189 compounds that 

are considered fo be HAP. Chromium 

compounds are included on this Ust of 

pollutants. Section 112(c) directs EPA to 

use this pollutant Ust to develop and 

pubUsh a Ust of source categories for 

which NESHAP will be developed. This 

list of source categories, which was 

pubUshed in the Federal Register on 

July 16,1992, includes major and area 

sources performing hard chromium 

electroplating, decorative chromium 

electroplating, and chromium 

anodizing. Thus, emissions of 

chromium compounds from these six 

source categories are being regulated by 

this proposed rulemaking. 

The preamble to the list of source 

categories (57 FR 31588) presents the 

rationale for listing the chromium 

electroplating and anodizing area source 

categories. That discussion is repeated 

in the following paragraphs, and EPA 

requests comment on whether there is a 

basis for removing from the source 

categories Ust any of the categories or 

subcategories covered by tiie proposed 

standards. Specific information is 

requested concerning whether the 

delisting criteria of section 112(c)(9) 

would be met, or whether, in the 

alternative, it would be appropriate, in 

the case of any proposed subcategory 

(such as decorative electroplating using 

the trivalent chromium process), to 

conduct an assessment under section 

112(c)(3) ofthe effect on human health 

or the environment before finally 

creating such subcategory and adding if 

fo the source category Ust. 

Chromium electroplaters can present 

an adverse health threat fo populations 

living near the source of emissions. 

Chromium electroplaters mostly emit 

the hexavalent form of chromium, 

Cr(+6), as chromic acid mist, and lesser 

amounts of trivalent chromium Cr(-t-3). 

Current health effects data suggest that 

the hexavalent form of chromium is the 

most toxic of all chromium compounds. 

Both human case studies and 

epidemiological studies attest to the 

adverse health effects from inhalation of 

hexavalent chromium. Acute exposure 

to hexavalent chromium has been 

shown fo cause nasal irritation in 

workers and other individuals. 

Intermediate and chronic inhalation 

exposure fo chromium has been 

reported to cause adverse respiratory 

tract effects, including irritation and 

perforation ofthe nasal mucosa, 

decreases in lung function, and renal 

proteinuria. Animal studies of acute 

organ toxicity also suggest that 

chromium compounds may produce 

kidney and Uver damage. 

The carcinogenic health effects from 

chromium ere also well documented. 

Hexavalent chromium is considered a 

Group A carcinogen because there is 

adequate evidence for its 

carcinogenicity in humans. Specifically, 

chronic occupational exposure to 

chromium has been associated with 

increased incidence of respiratory 

cancer in workers. The association of 

exposure fo chromium and the 

induction of lung cancer is strengthened 

by the high lung cancer mortality ratios 

found in various epidemiological 

studies, the consistency of results across 

several studies, the increased tumors 

found in association with increasing 

doses, and the specificity of the tumor 

site. The role of trivalent chromium in 

carcinogenesis is presently unclear. 

Reproductive studies on animals also 

suggest tiiat chromium compounds may 

have some fetal and maternal toxicity 

effects. Although conclusive results can 

not be drawn from the available data, 

studies suggest that chromium 

compounds can adversely affect fetal 

development and male reproduction in 

experimental animals. 

Recognizing the considerable 

uncertainties associated with cancer risk 

assessment, the Agency has developed 

nationwide emission and population 

exposure estimates associated with 

chrome platers and anodizers. Based on 

this analysis, the Agency estimates that 

chrome platers and anodizers contribute 

significantly to the total increased 

cancer incidence in the U.S. from 

airborne toxics. Hard chrome platers, 

decorative chrome platers, ana acid 

anodizers may cause as many as 110 

increased cancer cases per year in the 

U.S. In addition to significant 

population risks, chrome platers and 

anodizers contribute significantly to 

maximum individual cancer risks in the 

proximity of particular faciUties. The 

Agency estimates that maximum, upperbound individual risks range from two 

chances in 100,000 (2xl0-s) for small 

acid anodizing plants fo five chances in 

1,000 (5x10-3) for large hard plating 

operations. All estimates of risk in this 

analysis are based on hexavalent 

chromium only, and not on trivalent 

chromium. 

An Agency study of Southeast 

Chicago estimates that chrome platers 

contribute about one sixth of the total 

cancer incidence due fo all sources of 

airborne toxics in the study area, 

including steel mills, road vehicles, and 

other industrial sources. 

An Agency analysis of cancer 

incidence from air toxic emissions in 

five large U.S. cities shows that chrome 

platers contribute about one tenth of the 

total increased cancer incidence due to 

all sources of airborne toxics. 

Extrapolating the cancer rate in the five 
65782 Federal Register /Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

P.17 

cities to the U.S. yields an estimate of 

as high as 90 increased cases per year. 

Currently, the only Federal emission 

regulations for electroplaters are limited 

to OSHA workplace emission standards, 

designed specifically to Umit worker 

exposure. Fourteen States have adopted 

or proposed regulations for controlling 

chromium emissions from 

electroplaters. 

The Agency finds that the overall 

emissions, exposures, and known and 

suspected health impacts associated 

with chromium electroplaters and 

anodizers present a threat of adverse 

effects to human health. Based on the 

finding above, the Agency has included 

chromium electroplaters and anodizers 

on the initial Ust of categories of area 

sources. 

The six source categories subject to 

the proposed rulemaking were 

evaluated to determine if 

subcategorization ofthe source 

categories was justified. The Agency's 

analysis indicates that the decorative 

chromium electroplating source 

category should be subcategorized based 

on whether a chromic acid or trivalent 

chromium electroplating process is 

used. No subcategorization is 

recommended for the hard chromium 

electroplating and chromium anodizing 

source categories. 

The decorative chromium 

electroplating source category has been 

subcategorized depending on whether a 

chromic acid (hexavalent chromium) or 

trivalent chromium electroplating 

process is used. These two subcategories 

are being considered separately because 

the trivalent chromium electroplating 

process is very different from the 

hexavalent chromium electroplating 

process. Trivalent chromium 

electroplating solutions typically 

contain between 22 to 30 g/L (3 to 4 oz/ 

gal) of trivalent chromium. Chromic 

acid is considered a bath contaminant, 

and the total chromium concentration in 

trivalent baths is four times lower than 

that in chromic acid baths. Also, the 

trivalent chromium solutions contain 

wetting agents; these are used primarily 

to provide a uniform plate thickness 

across the entire surface area of the 

parts. While the wetting agents may also 

inhibit misting, this is a secondary 

purpose. In contrast, in chromic acid 

baths, wetting agents are specifically 

used to inhibit misting. Also, in a 

trivalent chromium process, the wetting 

agents are not added separately during 

the electroplating process. 

Electroplating solution composition is 

maintained through the use of automatic 

controllers that add specified amounts 

of a material on an Ampere-hour basis. 

• Addition of wetting agents alone may 

jeopardize the trivalent chromium bath 

chemistry. Because some emissions 

control is inherent in the trivalent 

chromium electroplating process, tanks 

using this process are only required to 

monitor the process, whereas those 

tanks with a chromic acid electroplating 

process are required to add wetting 

agent to the electroplating solution. 

Another consideration is that the 

trivalent chromium electroplating 

process, while suitable for the full range 

of decorative chromium electroplating 

tanks, has unique operating 

considerations. For eTxample, the 

trivalent chromium electroplating 

process is more sensitive to 

contamination than hexavalent 

chromium electroplating baths. Certain 

materials such as copper, zinc, and lead, 

which are commonly found in the metal 

parts being plated, may contaminate the 

trivalent chromium bath solution. Also, 

the finish color achieved with the 

trivalent electroplating process may 

differ from that traditionally obtained 

with chromic acid baths, and the 

difference in color may be unacceptable 

to the end user. Finally, with the 

trivalent chromium bath, additional 

posttreatment and rinsing tanks may be 

needed. 

Although the Agency did not find any 

basis for subcategorizing the hard 

chromium electroplating source 

category, it was determined that distinct 

size classes of faciUties existed in the 

source category. The rationale for 

selecting these sizes is based primarily 

on control costs, which are discussed in 

sections VI.C.4 and VI.C.5; the size 

distinctions are presented here because 

sections of this preamble that precede 

section VI.C.4. contain discussion using 

the size distinctions. 

For the purposes of this rulemaking, 

the distinction between small and large 

hard chromium electroplating faciUties 

within the source category is based on 

the maximum cumulative potential 

rectifier capacity at a faciUty. A tank's 

rectifier capacity determines the amount 

of current (amperes) that can flow 

through the plating solution (from the 

anode to the cathode). Maximum 

cumulative potential rectifier capacity is 

calculated as: 

( £ RCj) x 8,400 hr/yrx 0.7 

where: 

RQ=the rectifier capacity rating of an 

individual tank 

8,400 hr/yT=operating schedule based 

on 24 hr/d, 7 d/wk, 50 wk/yr 

0.7=the percent time the electrodes are 

energized 

Based on the model plant parameters 

used for this analysis, a small model 

plant would have one plating tank, with 

a maximum rectifier capacity of 10,000 

Amperes. The maximum rated capacity 

would be approximately 60 milUon Ah/ 

yr. Therefore, the cutoff between small 

and large faciUties has been estabUshed 

as 60 million Ah/yr. Existing faciUties 

would follow the same procedure in 

calculating their total maximum rectifier 

capacity. 

B. Selection of Emission Points To Be 

Covered by the Standard 

The primary sources of HAP within 

the chromium electroplating and 

anodizing source categories are the 

electroplating and anodizing tanks, 

which emit chromium compounds. 

These are the emission points that 

would be covered by the proposed rule. 

Other processes located at facilities that 

perform chromium electroplating and 

anodizing that emit small quantities of 

other HAP include surface preparation 

steps such as acid dipping and vapor 

degreasing are not covered by this 

NESHAP. The HAP emitted from these 

processes are acid mists and solvent 

vapors. Hazardous air pollutant 

emissions from other metal plating 

processes such as nickel, copper, and 

cadmium plating are also not included 

in the scope of this rule. The reasons for 

excluding these emission points are 

provided below. 

The Agency's study of chromium 

emissions from chromium electroplating 

and anodizing tanks was begun prior to 

the 1990 amendments to the Act. The 

study focused on chromium compounds 

only; information on sources emitting 

HAP other than chromium compounds 

had not been obtained. Therefore, only 

those sources emitting chromium 

compounds (i.e., the chromium 

electroplating and anodizing tanks) are 

included in this proposed rulemaking. 

The additional time that would be 

required to develop the necessary 

background information to regulate the 

associated surface preparation steps 

could unnecessarily delay regulation of 

the electroplating and anodizing tanks. 

The EPA is in the process of developing 

NESHAP for emissions from degreasing 

tanks that would cover such operations 

located at faciUties performing > 

chromium electroplating and anodizing. 

Metal finishing processes that produce 

acid mists are found in a variety of 

source categories, and EPA wiU 

consider these sources in a forthcoming 

5-year area source study. 
P.18 

m I Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

C. Selection of Basis and Level of 

Proposed Standards for Existing and 

New Sources 

1. Selection of MACT/GACT Approach 

Section 112 ofthe amended Act 

directs the Administrator to promulgate 

standards that: 

require ths maximum degree of reduction in 

emissions of the hazardous air pollutants 

. . . that tha Administrator, taking into 

consideration the cost of achieving such 

emission reductions, and any nonair quality 

health and environmental impacts and 

energy requirements, determines is 

achievable0 ° ° 

This control level is referred to as 

MACT. Section 112(d)(3) ofthe 

amended Act specifies the requirements 

for detennining MACT for new and 

existing sources. The MACT level is 

required for all major sources. However, 

the Administrator may elect fo 

promulgate standards or requirements 

appUcable fo sources in categories or 

subcategories of area sources that 

provide for the use of generally 

available control technologies (GACT) 

or management practices by such 

sources to reduce emissions of HAP. 

The GACT approach can be less 

stringent than the MACT floor, and it 

considers the availability of the 

emission control systems, their costs 

and economic impacts, and the 

technical capabilities of owners/ 

operators fo operate and maintain 

emission control systems. Under the 

GACT approach, a "floor" evaluation is 

not conducted for each category or 

subcategory fo assess the minimum 

allowable control. Also, the 

Administrator is not required to conduct 

a residual risk analysis to determine if 

more stringent standards are necessary 

to protect pubUc health under section 

112(f), although the Administrator may 

conduct such a residual risk analysis as 

appropriate. Such an analysis is 

required for source categories for which 

MACT is required. 

The criteria for distinguishing major 

from area sources are included in the 

definitions of major and area sources in 

section 112(a). A major source is one 

that emits or has the potential to emit, 

considering control, 9.1 Mg/yr (10 tons/ 

yr) or mora of any HAP or 22.7 Mg/yr 

(25 tons/yr) or more of any combination 

of HAP. An area source is, by definition, 

any stationary source of HAP that is not 

a major source. If is expected that for 

each ofthe six source categories covered 

by this proposed rulemaking, the 

majority of sources in each category will 

be area sources. Chromium emissions 

from an electroplating or anodizing 

operation alone are unlikely fo exceed 

the major source cutoffs. However, if the 

chromium electroplating or anodizing 

operation is located af a facility that 

meets the criteria for a major source due 

to HAP emissions from other operations, 

then if would be considered a major 

source for purposes ofthe proposed 

rule. 

The Administrator is proposing to 

regulate area sources performing 

chromium electroplating and anodizing 

under section 112(c)(3), based on a 

finding that they present a threat of 

adverse effects to human health or the 

environment (see section VI. A.). This 

proposal is based on data that show that 

a significant amount of hexavalent 

chromium, a known human carcinogen, 

is emitted fo the atmosphere from the 

chromium electroplating and anodizing 

tanks af the levels of chromium 

emissions that present a threat of 

adverse effects fo human health. 

In determining whether fo regulate 

area sources by applying MACT or 

GACT, the Administrator, also 

considered the availability of control 

technologies and the cost of compUance 

for area sources. The control 

technologies on which this proposed 

rulemaking is based include packed-bed 

scrubbers and composite mesh-pad 

systems for hard chromium 

electroplating operations and fume 

suppressants for decorative chromium 

electroplating and anodizing operations. 

Packed-bed scrubbers ara currently used 

widely in the hard chromium 

electroplating industry; composite 

mesh-pad systems are also being 

installed af all sizes of faciUties 

although their use is not yet as 

widespread as packed-bed scrubbers. 

Fume suppressants are used widely for 

decorative chromium electroplating and 

anodizing operations. Because of the 

availabiUfy of these control 

technologies, they would be considered 

appropriate bases for GACT as well as 

MACT. Also, the cost of applying these 

control technologies has been found fo 

be reasonable for most sources in these 

source categories (see section VI.C.4). 

Because of the high toxicity of 

chromium compounds and the 

availability and reasonable cost of 

control technologies, the Administrator 

is proposing to apply MACT to both 

major and area sources of chromium 

electroplating and anodizing. The 

appUcation of MACT to both area and 

major sources ensures that a residual 

risk analysis of emissions associated 

with these sources will be conducted by 

the Agency, as required by section 

112(f) of the Act, to determine whether 

additional regulation is warranted in the 

future to protect pubUc health. The 

agency solicits comments on the 

proposal to establish MACT standards 

for area sources instead of adopting 

GACT standards. ' 

2. Selection of the MACT Floor 

As discussed in section U.C, 

Cat egorization/Subcategorization: 

Determining Maximum Achievable 

Control Technology "Floors," EPA 

develops and considers regulatory 

alternatives that are af least as stringent 

as the MACT floor as defined in the Act. 

The MACT floor is determined from 

information on various control levels 

within each ofthe categories and 

subcategories (baseline conditions). The 

baseline conditions that led fo the 

development of the MACT floors are 

discussed below. Additional 

information on baseline conditions is 

found in Chapter 5 of the BID. 

a. Hard Chromium Electroplating 

MACT Floor. Baseline conditions that 

were originally established for facilities 

operating hard chromium electroplating 

tanks were based on an industry survey 

of 44 hard chromium electroplating 

operations that was conducted in 1987. 

Based on this survey and industry 

census data, it was estimated that 

baseline conditions for facilities 

operating hard chromium electroplating 

tanks included a total population of 

1,540 facilities. Of these tanks, 30 

percent were uncontrolled, 30 percent 

were controlled by chevron-blade mist 

eliminators, and 40 percent were 

controlled by packed-bed scrubbers. 

Chevron-blade mist eliminators 

represent a control device efficiency of 

approximately 95 percent at 

representative inlet loadings for hard 

chromium electroplating tanks. The 

associated outlet concentration is 0.15 

mg/dscm (6.6x10-6 gr/dscf). 

Alternatively, well-maintained and 

-operated packed-bad scrubbers that 

incorporate periodic washdown of the 

packing can achieve an emission 

reduction of 99 percent, with an 

associated outlet concentration of 0.03 

mg/dscm (1.3x10-3 gr/dscf) considered 

feasible. Although EPA believes that an 

undetermined number of existing 

facilities are operating packed-bed 

scrubbers under less-than-ideal 

operating and maintenance conditions, 

if proper operation and maintenance 

procedures are implemented, existing 

units will readily achieve an emission 

limit of 0.03 mg/dscm (1.3x10-3 gr/ 

dscf). 

More recent information obtained 

from control device vendors confirms 

that composite mesh-pads are being 

used af approximately 5 percent of hard 

chromium electroplating faciUties and 

that the growth in use is expected to 

continue. The vendor survey also 

indicated that these control devices are 

_ri_i._.. ,___, __4, _Uh_l__ • _i_g_ i 
65784 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 /Proposed Rules 

P.19 

being installed at all sizes of faciUties. 

Based on emission test results from 

three faciUties, a composite mesh-pad 

system can achieve an average outlet 

concentration of 0.013 mg/dscm 

(5.7xl0-« gr/dscf). Based on a 

representative inlet loading, the percent 

reduction achieved by the composite 

mesh-pad system is greater than 99.8 

percent. The current use of this system 

in the industry as weU as the fact that 

it represents the "maximum degree of 

reduction in emissions" (section 

112(d)(3) ofthe Act) resulted in the 

selection of 0.013 mg/dscm (5.7x10-6 

gr/dscf) as the MACT floor for new 

sources. 

Some uncertainty surrounds the exact 

effect that the increasing use of 

composite mesh-pads has on the 

original existing source baseline. The 

EPA has no information on whether the 

composite mesh-pad systems were 

installed to replace or augment existing 

packed-bed scrubbers or if they were 

installed at faciUties that were either 

uncontrolled or were using chevronblade mist eliminators. This 

uncertainty, however, does not affect 

the existing source MACT floor; the 

same level of control would represent 

the MACT floor whether the original or 

modified baseline conditions are . 

assumed. A discussion of how die 

existing source MACT floor is 

calculated under either circumstance is 

provided below. 

In the first MACT floor analysis, it is 

assumed that composite mesh-pads are 

not included in the baseline conditions. 

The existing source MACT floor is 

determined by calculating the average 

emission Umitation achieved by die best 

performing 12 percent of sources. 

Because it is estimated that 40 percent 

of the industry is currently using 

packed-bed scrubbers, and that a wellmaintained and -operated packed-bed 

scrubber that incorporates periodic 

washdown of the packing can achieve 

outlet concentrations of 0.03 mg/dscm 

(1.3x10-5 gr/dscf), this emission Umit 

(0.03 mg/dscm [1.3x10-* gr/dscf) is the 

MACT floor for existing sources. 

In the second MACT floor analysis, 

the baseline conditions are adjusted to 

account for the 5 percent of facilities 

using composite mesh-pads. In this 

scenario, the average emission 

Umitation associated with 5 percent of 

faciUties performing at 0.013 mg/dscm 

(5.7x10-6 gr/dscf) and 7 percent 

performing at the next highest level of 

control (0.03 mg/dscm [1.3x10 -- gr/ 

dscf]) results in an emission Umitation 

(0.023 mg/dscm [1.0x10-3 gr/dscf]) that 

does not correspond to any specific 

control technique. 

As noted earlier (in section n.C), 

when the average emission Umitation 

does not correspond to an emission 

Umitation achievable with a specific 

type of control technique, EPA may use 

the emission limitation achieved by the 

faciUty at the 94th percentile (the 

median of the best performing 12 

percent), which is equivalent to 0.03 

mg/dscm (1.3xl0-5 gr/dscf) in this case. 

This approach would result in an 

emission Umitation of 0.03 mg/dscm 

(1.3xl0-s gr/dscf) as the MACT floor for 

existing hard chromium electroplating 

tanks. Either of the approaches to 

determining the MACT floor described 

above results in the same level of 

control. 

b. Decorative Chromium 

Electroplating—Chromic Acid Bath— 

MACT Floor. Baseline conditions that 

were originally estabUshed for faciUties 

with decorative chromium 

electroplating tanks were based on an 

industry survey of 63 decorative 

chromium electroplating operations that 

was conducted in 1987. Baseline 

conditions for decorative chromium 

electroplaters using chromic acid baths 

include a total faciUty population of 

2,800 faciUties of which 15 percent of 

faciUties aro uncontrolled, 40 percent 

use fume suppressants, 40 percent use 

fume suppressants in combination with 

packed-bed scrubbers, and 5 percent use 

packed-bed scrubbers. Because the inlet 

concentrations in decorative chromium 

electroplating are lower than those in 

hard chromium electroplating, the 

overall efficiency of packed-bed 

scrubbers is also lower (approximately 

97 percent compared to 99 percent for 

hard chromium electroplating tanks). 

Alternatively, test results show that the 

use of chemical fume suppressants 

inhibit greater than 99.5 percent ofthe 

chromium from being released from an 

electroplating bath and are capable of 

achieving an outlet concentration of 

0.003 mg/dscm (1.3x10-6 gr/dscf). 

Because more than 12 percent ofthe 

faciUties in this source category use 

fume suppressants and no more 

effective control technique is available, 

the MACT floor for both new and 

existing decorative chromium 

electroplating tanks using a chromic 

acid bath is an emission Umitation of 

0.003 mg/dscm (1.3x10-6 gr/dscf). 

c. Decorative Chromium 

Electroplating—Trivalent Chromium 

Bath—MACT Floor. Appro:ximately 10 

percent of decorative electroplaters use 

trivalent chromium baths. As discussed 

in section VI.A., EPA has determined 

that decorative chromium electroplating 

tanks using a trivalent chromium bath 

are a separate subcategory. Tests 

conducted on tanks using trivalent 

chromium electroplating baths indicate 

that the total chromium concentration 

in emissions from these baths is 0.048 

mg/dscm (2.1x10-3 gr/dscf). Hexavalent 

chromium concentrations from these 

baths have been measured as 0.004 mg/ 

dscm (1.7x10-6 gr/dscf). 

Most trivalent chromium 

electroplating baths do not have 

ventilation systems such that the 

chromium concentration in emissions 

from these baths could be measured. 

Therefore, another parameter, surface 

tension, was measured during the 

emission tests; the tests indicated that 

trivalent chromium baths that meet the 

above emission levels should have 

surface tensions no greater than 55 

dynes/cm (3.8x10-3 lbf/ft). Based on 

these test data, the MACT floor for new 

and existing trivalent chromium 

electroplating tanks is operation ofthe 

bath consistent with the above 

concentrations (0.048 mg/dscm 

(2.1x10-3 gr/dscf)), as demonstrated 

through surface tension measurement. 

d. Chromium Anodizing Tanks MACT 

Floor. Baseline conditions that were 

originally estabUshed for faciUties with 

chromium anodizing tanks were based 

on an industry survey of 25 chromium • 

anodizing operations that was 

conducted in 1987. Baseline conditions 

for chromium anodizing tanks include a 

total faciUty population of 680 faciUties, 

of which 40 percent are uncontrolled, 

10 percent use chevron-blade mist 

eUminators, 20 percent use packed-bed 

scrubbers, and 30 percent use fume 

suppressants. Once again, the average 

emission limits achieved by the bestperforming 12 percent of the faciUties in 

this category are associated with the use 

of fume suppressants. Also, a more 

efficient control technique is not 

available. Therefore, the MACT floor for 

both new and existing chromium 

anodizing sources is an emission limit 

of 0.003 mg/dscm (1.3x10-6 gr/dscf). 

3. Regulatory Alternatives Considered 

The existing source regulatory 

alternatives developed to select existing 

source MACT for each of the categories 

and subcategories are presented in Table 

2. A brief discussion ofthe alternatives 

is presented below. More stringent 

control techniques beyond what would 

be required by the new source MACT 

floor are not available; therefore, no 

additional regulatory alternatives 

beyond the MACT floor were 

considered for new sources. 
P.20 

Federal Register / Vol. 58. No. 240 / Thursday. December 16, 1993 / Proposed Rules 65785 

TABLE 2.—SUMMARY OF REGULATORY ALTERNATIVES FOR EXISTING SOURCES 

Type of operationtoguistory attsrnsflve (RA) 

Hard chromium plating 

RA 1 (MACT floor) 

RAN' 

RAV ' 

Size of operation* 

SmaU (<60 million AWyr) 

P8S<> _ 

PBS 

PBS 

CMP—existing PBS exempt ... 

Largs (_-80 mHlton Ah/yr) 

PBS. 

CMP c—Existing PBS exempt 

CMP. 

CMP. 

CMP. 

Decorative, chromium plating—chron-,*: acid bath 

RA I (MACT floor) .... FS<* 

Decorative chromium oiatlng—trivalent chromium bath 

RA I {MACT floor) TVC' (no action) 

Chromium anodizing 

RA I (MACT floor) FS 

• Based on the maximum cumulative potential rectifier capacity of tanks at a facWty. 

«• PBS-Packed Bed Scrubber. 

cCMP-Compoaite Mesh Pad. 

" FS«Cbemlcal Fume Suppressant 

- TVC«Trtvaient Chromium Plating Process. 

a. Hard Chromium Electroplating 

Regulatory Alternatives. Far hard 

chromium electroplating, the EPA 

evaluated five regulatory alternatives as 

shown in Table 2. The alternatives 

increase is control stringency from 

Regulatory Alternative (RA) I, the 

existing source MACT floor control 

level, to RA V. The alternatives are 

ctured to determine whether a size 

or class distinction is appropriate in 

selection of MACT. Such a distinction is 

authorized by section 112(d)(1), which 

provides that the MACT standard may 

distinguish among classes, types, and 

sizes of sources within a category or 

subcategory. 

Regulatory Alternative I would 

require the control level achieved by 

packed-bed scrubbers for both small and 

large hard chromium electroplaters. 

Regulatory Alternative II would increase 

the stringency for large hard chromiiim 

electroplaters by requiring the control 

level achievable by composite meshpads unless the source is already 

controlled with a packed-bed scrubber. 

Regulatory Alternative III would further 

increase the stringency for large hard 

chromium electroplaters by requiring 

the control level achievable by 

composite mesh-pads for all sources, 

even those already controlled with 

packed-bed scrubbers. Regulatory 

Alternative IV would increase the 

stringency for small hard chromium 

electroplaters by requiring the control 

level achievable by composite meshpads, except for those already controlled 

by packed-bed scrubbers. Regulatory 

Alternative V would require the control 

level achievable by composite m 

pads for all small and large hard 

chromium electroplaters, with no 

exception 

b. Decorative Chromium 

Electroplabng—Chraxnic Acid Bath— 

Regulatory Alternative. The control 

technology that represents the MACT 

floor, i.e., the use of fume suppressants, 

is the highest level of control achievable 

by the subcategory. Therefore, only one 

regulatory alternative is possible. 

c. Decorative Chromium 

Electroplating—Trivalent Chromium 

Bath—Regulatory Alternative. There are 

no regulatory alternatives other than the 

no-action alternative for trivalent 

chromium processes. Because ofthe 

presence of a wetting agent as an 

integral part of the bath chemistry, and 

the low emission potential, no controls 

are currently in use for this process. 

d. Chromium Anodizing Tanks 

Regulatory Alternative. The control 

technology that represents the MACT 

floor, i.e., the use of fume suppressants, 

is the highest level of control achievable 

by the category. Therefore, only one 

regulatory alternative is possible. 

4. Nationwide Impacts of the Regula 

Alternatives 

This section presents the nationwide 

environmentaL energy, cost, and 

economic impacts of the R. ted 

in Table 2. For purposes of asm-* 

impacts, each RA is com pan 

baseline or no-actio 

baseline levels of control were obtair 

from responses to an industry survey 

conducted by EPA in 1985. The 

ded information on control 

techniques at 44 hard chrom 

electroplating facilities. 63 d<-

chromium electroplating facilities, and 

25 ch 

more recent follow-up survey of vendors 

supplying composite mesh-pads was 

also conducted after the initial survt> 

assess any changes in the con 

used in the industry. This survey 

demonstrated that composite mesh-pads 

were being installed on new and 

existing hard chromium electroplating 

tanks, regardless of facility size. 

As explained in section VI 

baseline conditions for thi• ara 

constantly ch. 

replace old control eqi 

new, more efficient control 

as composite mesh-pads. Th< 

presented here, however, are bas('< 

baseline conditions as established 

through tha initial industry survey. This 

is because the follow-up vendci 

did not provide specific information o_i 

whether the composite mesh-pads ware 

replacing previously uncontrolled Uu 

or tanks that had been i I h 

a less efficient COT 

in section VT.C.2. results ofthe \ 
P.21 

65786 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

survey indicate that approximately 5 

percent ofthe facilities within die hard 

chromium electroplating source 

category are using composite meshpads. Assuming that each composite 

mesh-pad was installed at a different 

facility, the maximum number of 

facilities widi these devices would be 

approximately 80 out of an estimated 

1,540 facilities. Given the relatively 

small number of composite mesh-pads 

being used, the nationwide impacts that 

would result if these facilities were 

accounted for in the baseline conditions 

would not differ significantly from those 

presented here. 

a. Baseline Conditions. For the 

purposes of Uiis analysis, die baseline 

conditions presented in the following 

paragraphs were used. 

For hard chromium electroplating, it 

was estimated diat, at baseline, 30 

percent ofthe tanks are uncontrolled, 30 

percent are controlled by chevron-blade 

mist eliminators, and 40 percent are 

controlled by packed-bed scrubbers. 

For decorative chromium 

electroplating, it was estimated diat, at 

baseline, 15 percent are uncontrolled, 

40 percent are controlled by chemical 

fume suppressants, 40 percent are 

controlled by chemical fume 

suppressants in conjunction with 

packed-bed scrubbers, and 5 percent are 

controlled by packed-bed scrabbers. In 

calculating aggregate nationwide 

impacts for decorative chromium 

electroplating tanks, the following 

control scenario was assumed for RA I: 

58 percent of the existing tanks will 

operate with chemical fume 

suppressants alone, and 42 percent of 

the existing tanks will operate with 

chemical fume suppressants in 

conjunction with packed-bed scrubbers. 

The combined use of techniques is 

common because packed-bed scrubbers 

serve a dual purpose. In addition to 

controlling air pollution, the scrubbers 

serve as atmospheric evaporators that 

concentrate the process rinse waters 

requiring treatment. Therefore, it is 

assumed that ousting tanks currently 

using chemical fume suppressants in 

conjunction with packed-bed scrubbers 

will continue Uiis practice and that half 

of Uie tanks that currently use packedbed scrubbers alone will opt to operate 

the scrubber in conjunction with fume 

suppressants. 

For chromium anodizing, it was 

estimated that, at baseline, 40 percent 

are uncontrolled, 10 percent are 

controlled by chevron-blade mist 

eliminators, 20 percent are controlled by 

packed-bed scrubbers, and 30 percent 

are controlled by chemical fume 

suppressants. 

No net growth is projected for Uie 

chromium electroplating and anodizing 

industry. Contacts with equipment 

suppliers indicate that Uie majority of 

new equipment installations occur at 

existing facilities as a result of 

replacement of obsolete capacity or 

expansion ofthe existing capacity. The 

equipment suppliers indicated that very 

few new facilities have been constructed 

in Uie last 5 years. Consequently, the 

nationwide impacts presented below are 

Uie impacts beyond baseline ofthe RA's 

on existing tanks only. Impacts on new 

facilities are presented at Uie end of Uiis 

section for typical, new model plant 

configurations only. 

b. Environmental Impacts. Estimates 

of nationwide emission reductions and 

energy and solid waste impacts 

associated with each regulatory 

alternative are presented in Table 3. The 

RA's correspond to those that were 

presented in Table 2. To determine 

impacts beyond baseline using the 

numbers on Table 3, subtract the 

baseline number from the total number 

for a given alternative. To determine 

incremental impacts between regulatory 

alternatives, subtract the value for the 

less stringent ofthe two alternatives 

from the value for the more stringent. 

TABLE 3.—ENVIRONMENTAL IMPACTS OF THE REGULATORY ALTERNATIVES 

Type of operation 

Decorative chromium plating—chromic acid plating process. 

Chromium anodizing 

RA 

Baseline ... 

RAI . . . 

RAII 

RAMI 

RAIV 

RAV 

Baseline ... 

RAI 

Baseline ... 

RA 1 

Nationwide emission estimate, Mg/yr 

(tons/yr)« 

Small (<60 million Atvyr) 

18.5 (20.3) 

0.54 (0.59) 

0.54 (0.59) 

0.54 (0.59) 

0.28 (0.3) 

0.11 (0.12) 

Large (260 million Ah/yr) 

126.6 (139.3) 

3.7 (4) 

1.93 (2.12) 

0.74 (0.81) 

0.74 (0.81) 

0.74 (0.81) 

10.5(11.5) 

0.3 (0.3) 

3.6 (3.9) 

0.04 (0.05) 

Nationwide energy Impacts, 

MWh/yr •> 

Small (<60 

million Ah/ 

yr) 

20,300 

26,600 

26,600 

26,600 

> 34,797 

40,284 

Large (_60 

million Ah/ 

112,300 

136,000 

183,370 

215,220 

215,220 

215,220 

106,000 

105,000 

48,000 

45,000 

Nationwide solid waste impacts, m3

/yr (fP/yr)« 

Small (<60 

million Ah/yr) 

18(640) 

44 (1,550) 

44(1,550) 

44(1,550) 

78 (2,750) 

103 (3,640) 

Large (_60 

million Ah/yr) 

26(820) 

64(2£60) 

118(4,170) 

156 (5,510) 

156(5,510) 

156 (5,510) 

67 (2,400) 

63 (2,200) 

8 (280) 

0(0) 

• For the nationwide emission estimate calculations, refer to Chapter 6, Section 6.2 of the BID for Proposed Standards. 

>>For the nationwide energy impact calculations, refer to Chapter 6, Section 6.3 of the BID for Proposed Standards. 

°For the nationwide solid waste impact calculations, refer to Chapter 6, Section 6.5 of the BID for Proposed Standards. 

Impacts on wastewater treatment or 

discharges were considered negligible 

because ofthe industry practice to 

recirculate control device effluent back 

to Uie electroplating tanks as makeup to 

compensate for evaporative losses. Solid 

waste is generated as a result of Uie need 

to periodically replace packing and 

mesh material used in the control 

systems. The nationwide solid waste 

impact is based on Uie frequency of 

replacement, Uie volume of material per 

control device, a compaction factor of 

50 percent prior to disposal, and Uie 

estimated number of tanks nationwide. 

i. Hard Chromium Electroplating 

Tanks—RA 1. For hard chromium 

electroplating tanks, RA I represents a 

97 percent reduction in Uie nationwide 

baseline emissions. The total 

nationwide emission reduction 

associated with Uiis alternative is 140 

Mg/yr (155 tons/yr). 

The total nationwide energy impact 

beyond baseline of RA I is 

approximately 30,000 MWh/yr. This 

increase and Uie incremental increases 

in energy impacts between RA's are due 

to increases in Uie pressure drop across 

control systems and their corresponding 
P.22 

Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rales 65787 

increase in the fan horsepower 

requirements. 

The total nationwide solid waste 

impact beyond baseline is 84 m-Vyr 

(2,260 fta/yr). The increase in solid 

waste over baseline is due to increases 

in die number of tanks using control 

systems that require periodic disposal of 

packing material. 

Reg-Uatory Alternative U. The total 

nationwide emission reduction 

associated with RA n is 143 Mg/yr (157 

tons/yr). The total nationwide energy 

impact beyond baseline of RA II is 

approximately 77,000 MWh/yr. The 

total nationwide solid waste impact 

beyond baseline is 118 ms/yr (4,170 I 

Regulatory Alternative BJ. The 

nationwide emission reduction beyond 

baseline associated with RA LD is 144 

Mg/yr (159 tons/yr). The total 

nationwide energy impact beyond 

baseline of RA DI is approximately 

109,200 MWh/yr. The total nationwide 

solid waste impact beyond baseline is 

156 mVyr (5,500 ftVyr). 

Regulatory Alternative IV. The 

nationwide emiasion reduction beyond 

baseline associated wilh RA IV is 144 

Mg/yr (159 tons/yr). Ths total 

nationwide energy impact beyond 

baseline of RA IV is approximately 

117,400 MWh/yr The total nationwide 

solid waste impact beyond baseline is 

190 mVyr (6.700 ftVyr). 

Regulatory Alternative V. The 

nationwide emission reduction beyond 

baseline associated with RA V is 144 

Mg/yr (159 tons/yr). The total 

nationwide energy impact beyond 

baseline of RA V is approximately 

122,900 MWh/yr. The total nationwide 

solid waste impact beyond baseline is 

215 mVyr (7,590 fWyr). 

•3 chromium 

electroplating tanks*-chromic acid 

bath. Regulatory Alternative I 

corresponds to a 97-percent reduction 

against nationwide baseline amission 

levels. The nationwide emission 

reduction associated with' 

alternative is 10 Mg/yr (11 tons/yr). 

Thera is no energy impact associated 

with RA L In fact, the nationwide 

energy requirement for RA I is projected 

to be lower than that at baseline because 

of the discontinuation of add-on control 

systems on some decorative chromium 

tanks. There is no increase in the 

amount of solid waste generated under 

RA I because there is ao solid waste 

associated with the use of chemical 

fume suppressants. The solid waste 

generated under this alternative is 

associated with those tanks that 

continue to operate packed-bed 

scrubbers in conjunction with fame 

suppressants. 

iii. Decorative chromium 

electroplating tanks—trivalent 

chromium bath. Regulatory Alternative 

I, which is a no-action alternate 

represents no additional emission 

reduction from baseline. There are a. 

no energy or solid waste imp 

iv. Chromium anodizing tanks. 

Regulatory Alternative I corresponds to 

an emissions reduction of 99 percent or 

3.5 Mg/yr (4 tons/yr). The energy 

impacts associated with RA I represent 

a decrease of 8 percent from baseline. 

This decrease is due to the 

discontinuation of packed-bed scrubbnrs 

and chevron-blade i nators et 

those tanks that currently use these 

control systems. Regulatory Alternative 

I would also reduce the amount of so 

waste generated by 100 percent. Si 

waste is generated at baseline 

conditions due to the use of packed-bed 

scrubbers. No solid waste is generated 

from the use of chemical fu 

suppressants. 

c. Cost Impacts. Aggrej 

capital and net annua!' 

each RA are presented in Tah 

TABLE 4.—COST IMPACTS OF THE REGULATORY ALTERNATIVES 

Type of operation 

Hard chromium 

piatrng. 

mium paring. 

Chromium anodizing. 

RA 

RAf 

RAH 

RAIIi 

RAIV 

RAV 

RAI 

RAI 

Nationwide capital coats, 

miWons • 

Small (-.60 

mWonAh/ 

yr* 

19.5 

19.5 

19.5 

12.6 

11.4 

Large (2_>0 

million Ah/ 

yr) 

22:3 

21.3 

25.1 

25.1 

25.1 

Nationwide annualized 

costs, millions1 

Small (<60 

nHtnMyr) 

5.2 

S.2 

5.2 

7.6 

9 8 

Lame (280 

mill& Ah/ 

yr) 

e.T 

12.2 

17.1 

17.1 

17 1 

Nationwide emission reduction Mg/ 

yr" (ton/yr) 

140.86(155) 

142.66(156.9) 

143.82 (158.2) 

144.08(158.5) 

144.25 (158.7) 

10.2(112) 

3.56 (3.9V 

Incremental cost-effectiveness, SrMg {$•'• 

80.000 (73.000) 

3.400.000 (3.100.000) 

4,200,000 (3,800.000) 

8,200,000 (8.400,000) 

12,900,000(11.700,000) 

0(0) 

0(0) 

• For furtrher description of the nationwide cost Impacts refer to Chapter 7, Section 7.8 of me BID for Proposed Standards. 

"Nationwide emission estimate* are provided in Table 3: Emission reduction* are calculated by subtracting the emiesione eeeocialed with e 

given alternative from the baseline emission estimate. 

«Incremental cost-effectiveness Is calculated by dividing the incremental cost of two alternatives by the Incremental emission reduction. In this 

Taste, the Incremental cost-effectiveness of an alternative is calculated by compering it to Ihe previous alternative. Estimates calculated trom the 

costs and emission reductions presented In this table may not match the actual estimates presented In this column due to rounding. 

i. Hard Chromium Electroplating 

Tanks—RA I Regulatory Alternative I 

would result in nationwide increases in 

capital and annualized costs beyond 

baseline of $42 million and $11 million 

per year, respectively. The incremental 

cost of RA I compared to baseline is 

approximately $80,000/Mg (573,000/ 

ton). 

flegumtory Alternative II With RA II. 

nationwide capital and annualized cost 

increases beyond baseline are $41 

million and $17 million per year, 

respectively. The capital costs for large 

facilities are actually lower than they 

were for RA I even though a more 

stringent control technology is required. 

This ia because composite mesh-pads 

have a lower capital cost, but higher 

annual cost, than packed-bed scrubbers. 

The incremental cost effectiveness of 

RA II compared to RA I 

approximately $3.4 rnilllon/Mg (33.1 

million/to 

Regulatory Alternative Rl. For RA Iff, 

the nationwide capital cost increase 

beyond baseline that would result from 

RA III is $45 million, and the 

annualized cost increase beyond1 

baseline is $22 million. The incremental 

cost effectiveness of RA HI compared to 

RA n is $4.2 million/Mg ($3.7 miHJon/ 

ton). 
P.23 

65788 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

Regulatory Alternative IV. Regulatory 

Alternative IV results in nationwide 

capital and annualized cost increases 

beyond baseline of $38 million and $25 

million per year, respectively. Once 

again, the requirements for composite 

mesh-pads, this time at small hard 

chromiiun electroplating facilities, 

result in decreases in capital costs and 

increases in annual operating costs. The 

incremental cost effectiveness of RA IV 

compared to RA in is approTximately 

$9.2 million/Mg ($8.4 million/ton). 

Regulatory Alternative V. Regulatory 

Alternative V results in nationwide 

capital and annualized cost increases 

beyond baseline of $37 million and $27 

million per year, respectively. The 

capital cost decrease (and annualized 

cost increase) compared to RA IV is due 

to the addition ofthe small hard 

chromium electroplating facilities that 

are required to replace existing packedbed scrubbers with composite meshpads. The incremental cost effectiveness 

of RA V compared to RA IV is 

approximately $12.9 million/Mg ($11.8 

million/ton). 

Tiie total annual reporting and 

recordkeeping costs would be 

approximately $8.6 milUon. These costs 

are the same tor all the regulatory 

alternatives. 

ii. Decorative chromium 

electroplating tanks—chromic acid 

electroplating solution. For decorative 

chromium tanks using a chromic acid 

electroplating process, there is no 

nationwide capital cost increase beyond 

baseline associated with RA I because 

there are no capital costs associated 

with the use of chemical fume 

suppressants. The capital and 

annualized costs projected under RA I 

are driven by the assumption that 42 

percent ofthe facilities will elect to use 

packed-bed scrubbers in conjunction 

with chemical fume suppressants. In 

fact, a slight decrease in nationwide 

baseline costs are eTxpected under RA I 

because ofthe discontinuation of some 

add-on pollution control equipment at 

some decorative chromium 

electroplating faciUties. However, the 

total annual reporting and 

recordkeeping costs would be 

approximately $14 milUon. 

iii. Decorative chromium 

electroplating tanks—trivalent 

chromium electroplating solution. As 

previously stated, RA I for those 

decorative chromium electroplating 

faciUties using a trivalent chromium 

bath is a no-action alternative. Thus, 

there are no control cost impacts. 

However, the total annual reporting and 

recordkeeping costs would be 

approximately $1.6 milUon. 

iv. Chromium anodizing tanks. 

Regulatory Alternative I for anodizing 

tanks has no capital costs because fume 

suppressants require no equipment 

purchases. There is no annualized 

control cost impact beyond baseline for 

RA I. In fact, nationwide annualized 

costs are expected to decrease under RA 

I due to the discontinuation of add-on 

poUution control systems that are less 

effective and are more costly than fume 

suppressants. However, the total annual 

reporting and recordkeeping costs 

would be approximately $3.8 million. 

d. Economic Impacts. The following 

section presents the economic impacts 

associated with each RA. Economic 

impacts were assessed by examining the 

effect ofthe RA's on the cost of 

electroplating and on the final endproduct prices. In addition, the effect of 

each RA on small businesses was 

estimated in a smaU businesses impact 

analysis. This analysis used EPA's 

Office of PoUcy, Planning, and 

Evaluation's 1982 Regulatory Flexibility 

Act guidelines to determine if there 

were significant impacts on a 

substantial number of small businesses. 

According to those guidelines, the 

following criteria constitute a significant 

adverse economic impact: (1) Annual 

compUance costs increase the total cost 

of production for smaU entities by more 

than 5 percent; (2) compUance costs as 

a percentage of sales for small entities 

are at least 10 percent higher than 

compUance costs as a percentage of 

sales for large entities; (3) capital costs 

of compUance represent a significant 

portion of capital available to small 

entities, considering internal cash flow 

S

>lus external financing capabiUties; and 

4) the requirements ofthe regulation 

are likely to result in closures of small 

entities. 

i. Hard chromium electroplating 

operations—Regulatory Alternative I. 

The economic impacts associated with 

RA I for hard chromium electroplating 

operations are not significant. End 

product price increases are well below 

1 percent. The estimated number of 

small business closures for RA I ranges 

from 14 to 20 of the 1,170 small hard 

plating operations. Based on an analysis 

ofthe common financial ratios used by 

banks to assess loan appUcations for 

typical small faciUties, there are no 

capital availabiUty problems under RA 

I. All operations should be able to 

acquire the capital necessary to install a 

packed-bed scrubber system if they do 

not already have one. 

Regulatory Alternative II. Regulatory 

Alternative II does not result in 

significant economic impacts. Once 

again the end product price increases 

are less than 1 percent. For RA II, the 

estimated number of closures ranges 

from 20 to 23. Capital availabiUty 

problems are also avoided under RA II 

for the following reasons. First, smaU 

operations are required to use packedbed scrubbers for which the capital 

costs should not be prohibitive. Second, 

large faciUties that currently use 

packed-bed scrubbers may continue to 

use these devices and thus will have 

little or no capital requirements to meet 

the regulation. Finally, because the 

capital cost of composite mesh-pad 

systems is actually lower than that of 

packed-bed scrubbers, large faciUties 

required to use composite mesh-pads 

will not have problems obtaining the 

necessary capital. 

Regulatory Alternative IU. The 

estimated number of closures under RA 

III ranges from 20 to 28. However, the 

end product price increases resulting 

from this alternative are still 

insignificant (below 1 percent). Also, 

because RA D3 requires a control level 

equivalent to that of composite meshpad systems for aU large faciUties, while 

the required control level for small 

faciUties continues to be equivalent to 

the use of packed-bed scrubbers, there 

are no capital availabiUty problems 

because larger faciUties should be able 

to obtain the necessary capital. 

Regulatory Alternative IV. The end 

product price increases remain below 1 

percent, and the estimated number of 

closures ranges from 33 to 39 under RA 

IV. In addition, capital availability 

problems are avoided because RA IV 

allows small faciUties that currently use 

packed-bed scrubbers to continue using 

those systems. Other small faciUties 

may have to purchase a composite 

mesh-pad system, but because the 

capital cost of this type of system is 

lower than that of a packed-bed 

scrubber, smaU faciUties should be able 

to obtain the required capital. 

Regulatory Alternative V. Under RA 

V, end product price increases are -

below l percent, and the number of 

- estimated closures ranges from 37 to 51. 

However, because RA V requires all 

hard chromium electroplating 

operations to use composite mesh-pads 

regardless of whether they currently 

operate a packed-bed scrubber, some 

small faciUties currently using packedbed scrubbers may have a difficult time 

acquiring the necessary capital to 

purchase a composite mesh-pad system. 

Financial institutions may not be 

willing to lend the necessary capital to 

retrofit or replace an existing packedbed scrubber to a small faciUty that is 

still paying for those existing systems. 

ii. Decorative chromium 

electroplating and chromium anodizing 

operations. The economic impacts 
P.24 

:s_ / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

associated with the regulatory 

alternatives for both decorative 

chromium electroplating and chromium 

anodizing operations are not significant. 

For decorative chromium operations 

using the chromic acid plating process 

and for chromium anodizing operations, 

this pssulte from'tha extremely low 

as___&l control cost. Small increases in 

both th® electroplating costs (less than 

5 parcsnt) and the anodizing costs (less 

than 7 percent) are estimated in the 

economic analysis. As a result, end 

product price increases are also very 

small (less than 1 percent). The RA for 

decorative chromium operations using 

the trivalent chromium plating process 

is no action; thus, there is no economic 

impact. No small business closures are 

expected for either decorative 

chromium electroplating or chromium 

anodizing operations due to the low cost 

of control. 

e. Environmental and Cost Impacts 

for New Tanks. This section presents 

environmental and cost impacts for new 

tanks. These impacts are provided on an 

individual model plant basis and are 

calculated against a baseline of no 

control. No aggregate nationwide 

impacts for new facilities are presented 

because there are no reliable estimates 

for totaUy "new" faciUties. 

Environmental and cost impacts for 

new hard and decorative chromium 

electroplating tanks are presented in 

Tables 5 and 6, respectively. For hard 

chromium electroplating tanks, the 

proposed standard requires the 

application of composite mesh-pad 

systems, which corresponds to a 99.8-

percent reduction in uncontrolled 

emissions. Energy impacts for 

composite mesh-pad systems vary from 

37,300 to 895,200 kwh/yr. The solid 

waste impact resulting from the 

application of composite mesh-pad 

systems is low, ranging from 0.19 to 1 

mVyr (7 to 35 ftVyr). The capital costs 

for composite mesh-pad systems range 

from $27,200 to $143,600; the annual 

operating costs range from $13,500 to 

$76,700. 

TABLE 5.—ENVIRONMENTAL AND COST IMPACTS OF CONTROL TECHNIQUES AT NEW HARD CHROMIUM PLATING 

OPERATIONS 

Control technique/model plant size 

Emission reduction, ha/Vr 

(lb/yr) 

Energy impact Solid waste 

Impact, rrP/yr 

(ftVyr) 

Capital costs, 

(dollars) 

Not annual 

cost, S/yr 

Composite mesh-pad systems: 

Small 

Medium 

50(110) 

420 (924) 

1,600(3,520) 

37,300 

261,000 

895,200 

0.19 (6.7) 

0.52 (18) 

1.0(35) 

27,200 

71,800 

143,600 

13,500 

32,800 

78,700 

TABLE 6.—ENVIRONMENTAL AND COST IMPACTS OF CONTROL TECHNIQUES AT NEW DECORATIVE CHROMIUM PLATING 

OPERATIONS 

Control technique/model plant size 

Chemical fume suppressants: 

Small 

Medium 

Large 

Emission reduction, ttg/yr 

(lb/yr) 

6.0 (13) 

23.9 (52.6) 

239 (526) 

Enargy impact, 

hwh/yr 

14,900 

59,700 

156,700 

Solid waste 

impact, rrta/yr 

(fP/yr) 

0(0) 

0(0) 

0(0) 

Capital costs, 

(dollars) 

ooo 

Net annual 

cost, S/yr 

1,000 

3,300 

17,200 

For decorative chromium tanks, using 

a chromic acid electroplating process, 

the use of chemical fume suppressants 

represents a 99.5-percent reduction in 

uncontrolled emission levels. No energy 

or soUd waste impacts are associated 

with chemical fume suppressants. Also, 

no capital investment is associated with 

chemical fume suppressants, and the 

annual control costs are low, varying 

from $l,000/yr for a small operation to 

$17,200/yr for a large operation. 

New decorative chromium tanks that 

use a trivalent chromium process would 

have no cost or energy impacts because 

if is assumed they would comply with 

the standard simply by using tiie 

trivalent chromium bath. 

The only control technique examined 

for new chromium anodizing tanks was 

the use of chemical fume suppressants. 

The use of chemical fume suppressants 

represents a 99.5-percenf reduction in 

uncontrolled emission levels. The 

annual operating costs associated with 

fume suppressants range from $1,600 for 

small tanks fo $4,300 for large tanks. No 

energy or soUd waste impacts are 

associated with fume suppressant usage. 

Also, no capital investment is associated 

with fume suppressant usage. 

5. Selection of MACT 

a. New Source MACT. In aU cases, 

MACT for new sources is based on the 

MACT floor for new sources presented 

in section VI.C.2., Selection ofthe 

MACT floor, above. For hard chromium 

electroplating sources, new source 

MACT is a total chromium emission 

limit of 0.013 mg/dscm (5.7x10-6 gr/ 

dscf), which is based on the use of 

composite mesh pads. An emission 

limit of 0.003 mg/dscm (1.3xl0~«gr/ 

dscf), which is based on the use of fume 

suppressants, represents new source 

MACT for decorative chromium 

electroplaters using chromic acid baths 

and for chromium anodizing tanks. For 

those decorative chromium 

electroplating tanks that use a trivalent 

chromium electroplating process, new 

source MACT is the continued 

operation of the trivalent chromium 

electroplating process, with monitoring 

of the surface tension required. In each 

case, the new source MACT floor 

represents the "emission control that is 

achievedin practice by the best 

controlled similar source." The EPA 

considered whether there were any 

classes within the categories where the 

MACT floor did not represent the level 

associated with the "best controlled 

similar source" but did not find any 

such classes. 

b. Existing Hard Chromium 

Electroplating MACT. To determine 

MACT for hard chromium 

electroplating, EPA evaluated the 

emission reductions, costs, economic 

impacts, and other environmental and 

energy impacts of the MACT floor 

control level (achievable with packedbed scrubbers) and levels of control 

more stringent than the floor (achievable 

with composite mesh pad systems). 

These impacts were evaluated 
6-790 Federal Register / Vol. 58, No.. 240 / Thursdhy, December 16, 1993 / Pkaposed Rules 

separately for small and large-platers 

and for platers already welt-controlled 

(with packed bed scrubbers), These sizearid class distinctions were made fbir 

analytical purposes as authorized by 

section 112(d)(1) of the Act which 

provides that the Administrator may 

distinguish among,classes, types,.and 

sizes of sources within a. category or 

subcategoryih estabhshing standards. 

Section VT. €.3 of this preamble 

describes the regulatory alternatives 

(RA's). For small platers, RA's I, IT, and 

III would" all require the floor level of 

control. Regulatory Alternative IVis 

more stringent, arid RA V would require 

the moststtingent control.. For largeplaters, RA I would require the floor 

level of control, RA II is more stringent, 

and RA's HI, IV;.and V would aU.require 

the most stringent control. 

The following.discussion of the 

primary factors EPA considered in 

determining MACT provides separafe 

rationales for small and large platers. 

The primary factors that affected'the 

decision are the emission reductions: 

achievable, the Gost of control, and the 

economic impacts-. As-descrihed in 

section- VI.C.4 of this preamble, the 

other environmental (soUd wasta and 

water) and energy impacts of various 

alternatives would not be significant. 

Therefore, they were not primary factors 

in.the MACT decision and are not 

discussed in this section.. 

The.regulatory analysis.discussed 

below indicates what appear to be very 

high costs of control compared to the 

associated chromium emission 

reductions for all the regulatory 

alternatives. However, when the high 

toTxicity of chromium and the proximity 

of exposed'populations to electroplating 

facilities are considered, the: costs of 

control are found to be as reasonable as 

those for other pollutants in other 

source categories. One pound of 

chromium is roughly equivalent in 

cancer potency, fo 1500 pounds of 

benzene.. Specifically, the factor of 1,500 

results from a quantitative comparison 

ofthe unit risk estimates for. benzene 

and chromium. While quantitative 

comparison&of potencies of carcinogens; 

cany with.them considerableuncertainties, the highly toxic nature of 

chromium means that very small 

quantities of emissions can cause-air 

poUution with very, serious-adverse 

healthimpactsonthe surrounding 

population. For this reason, higher, costs 

of continuing a given quantity of these 

emissions would he more acceptable 

than for a Tesa toxic-pollutant. 

c. Small hard chromium 

electroplaters,. As shown.in Tables 3. and 

4, for small platers, a. significant 

emission reduction. (18-Mg/yx (19,7 

tons/yr)} beyond baseline would ba 

achieved byRA's;I„n, axtdini (packedr 

bed scrubbers), at an incremental, 

annualized cost af $5.2 million per year: 

This results in an incremental cost 

effectiveness of $290,000 per Mg 

($260,000 per ton). This is equivalent to 

$130/lh of chromium emission 

reduction, which is comparable to 

appi_orim_lely. $200/ton of benzene 

emission reduction ..if relative cancer 

potency, is;factored in. The economic 

impact.o£i_quii_ng:pa_ked-bed 

scrubbers am small platers would not be 

significant. The EPA's economic impact 

analysis found that most smaU platers 

could obtain funds to install and operate 

the scrubbers without serious adverse 

impacts. A typical small plater has sales 

revenue of $1 milUon, and for an 

uncontroUed faciHty the capital and 

annualized costs- df packed^bed scrubber 

control, would be:$36,700 and $9,800, 

respectively. However, the retrofit costs 

of installing packed-bed scrubbers for 

facilities with less efficient control 

systems would be higher: The 

nationwide incremental capital cost 

increase would be $20 million. 

Regulatory Alternative IV is more 

stringent thin RA HI for small'platers in 

that it would require the use of 

composite mesh-pads for all faciliiiesexceptthose, already controlled with 

packed-bed scrubbers. The nationwide 

incremental emission reduction of RA 

IV compared to RA in would be 0.26 

Mg/yr (Q.29 ton/yr) at an incremental 

annuahzed cost of $2.4 million per year.. 

Thisresults in an incremental cost 

effectiveness of$9.2 million/Mg ($8.4 

million/ton) of chromium emission 

reduction. This ia equivalent to. $4,1780/ 

lb of chromium-emission.reduction,, 

which, is comparable to. approximately 

$6,000/ton of benzene emission 

reduction, if relative cancer, potency is 

factored in. Thus, a smaU incremental 

emission reduction would- be achieved 

at a significant increase in anhuaUzed 

cost. The economic impact of RA IV 

would, not ba significant because' small, 

platers could abtainscapitalfbr 

composite' mesh pads as readily as they 

could for packed-bed scrubhers„and 

replacement of existing; packed-bed 

scrubbers- would notba required under 

this altemativa.. For a typical 

uncontrolled smaU plater, the capital 

cost for a» composite mesh-pad system 

would be $27,200-, which is lower than 

that for a packed-bed scrubber; however; 

the annualized cost would be $13,500 

which is higher than that for the 

packed-bed scrubber..Thenationwide 

capital costs for RA.IV compared to. RA 

III wouldba$7 million less than for RA 

III because-tha capital costs, for 

composite mesh-pad systemsarelower 

than for packed-bed scrubbers.. 

Regulatory Alternatives V iismjora 

stringent than- RA.IV far small platars.in 

that it would require: tha use of 

composite-mesh pads for all facilities. 

This means that those currently 

controlled with packed-bed scrubbers 

would be. required to replaca them, with 

composite mesh padsor retrofit them to 

achieve the mora stringent control level. 

The nationwide incremental emission 

reduction of 0.17 Mg/yr (0.19 tan/yr) 

would be achieved at an incremental 

annualized cost of $2:2 million per year.. 

This-is a-significant costincreasB 

compared to the assoaatedemission 

reduction. This results in an 

incremental cost effectiveness of $12.9 

milli'on/Mg ($11.7 milUon/tbn) of 

chromium emission reduction. This is 

equivalent to $5,900/lb of chromium 

emission reduction, which is 

comparable toappro3dmately$8,000/ton 

of benzene emission reduction,.if 

relative cancer potency is-factored ia> 

The incremental cost effectiveness of 

RA V compared to.RA.mi& $10.7 

milHon/Mg ($9.7 million/ton) of 

chromi'um emission reduction. This is 

equivalent to. $4i900/lb. of chromium 

emission reduction, which is 

comparable to approximately $7,000/ton 

of benzene emission reduction, if 

relative cancer potency is factored in. 

The incremental impacts of RA V 

compared to RA IV orRA UI are 

considerably higher than those of RA III 

compared to RA I orH. Small platers 

would find it'difficult or impossible to 

obtain thaneGessary capital to replace 

or retrofit existing packed-bed scrubbers 

with composite mesh-pad systems. 

The Administrator has selected RA HI, 

the MACT floor level of control, as tha 

basis forthe proposed MACT standard 

for small hard chromium electroplaters. 

This selection is based on- consideration 

of the significant emission reductions 

achievable at reasonable costs and1 other 

environmental, energy and economic 

impacts..The more stringent RA's-IVand 

V were, rejected because the incremental 

costs of control.and econorcucimpactswould be. unreasonable when compared 

to the: small'incremental emissionreduction that would be achieved. 

However, comments are specifically, 

requested on this decision and whether 

a different control level should be 

required in the final standard. 

Commenters on this issue should 

provide'supporting rationale for their 

positions. 

&. Large, hard chromium 

electroplaters.. As- shown in Tables. 3 and 

4, for large hard.platers„t__t-nationwide 

emission reduction that would, be; 

achievedbyrequiring packed^-bed 
P.26 

er / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules S5791 

scrubbers under RA I, the MACT floor 

level of control, would be about 123 Mg/ 

yr (136 tons/yr) at an annuaUzed cost of 

$6.1 milUon per year. This results in an 

incremental cost effectiveness of 

$49.600/Mg ($45,100/ton) of chromium 

emission reduction, equivalent to $22/lb 

of chromium emission reduction, which 

is comparable to approTximately $30/ton 

of benzene emission reduction if 

relative cancer potency is factored in. 

The nationwide capital costs would 

increase by $22 million. There would 

not be a significant adverse economic 

impact on large platers under this 

alternative and facilities could afford 

the installation and operation of packedbed scrubbers. 

Regulatory Alternative II is more 

stringent than RA I for hard platers in 

that it would require the use of 

composite mesh pads for all facilities 

except those already controlled with 

packed-bed scrubbers. The incremental 

emission reduction of RA II compared to 

RA I would be 1.8 Mg/yr (1.9 tons/yr) 

at an incremental annualized cost of 

$6.1 million per year. This results in an 

incremental cost effectiveness of $3.4 

million/Mg ($3.1 milUon/ton) of 

chromium emission reduction, 

equivalent to $l,600/lb of chromium 

emission reduction, which is 

comparable to approximately $2,000/ton' 

of benzene emission reduction if 

relative cancer potency is factored in. 

The nationwide incremental capital 

costs would decrease by $1 million 

rather than increase because the capital 

cost for a composite mesh-pad system is 

lower than for a packed-bed scrubber. 

The economic impact of RA II on large 

hard platers would not be significant; 

they could afford the cost of installation 

and operation of the required controls. 

Regulatory Alternative III is the most 

stringent alternative for large hard 

platers (RA's IV and V would require 

the same level of control) in that 

composite mesh-pads would be required 

for all facilities. The incremental 

emission reduction of RA III compared 

to RA II would be 1.2 Mg/yr (1.3 tons/ 

yr) at an incremental annualized cost of 

$4.9 million per year. This results in an 

incremental cost effectiveness of $4.2 

million/Mg ($3.8 million/ton) of 

chromium emission reduction, 

equivalent to $l,850/lb of chromium 

emission reduction, which is 

comparable to approximately $2,000/ton 

of benzene emission reduction if 

relative cancer potency is factored in. 

(The incremental cost effectiveness of 

RA III compared to RA I is $3.7 million/ 

Mg, $3.4 milUon/ton, $l,700/lb of 

chromium, or approximately $2,000/ton 

of benzene reduction.) The nationwide 

incremental capital costs would 

increase by $3 milUon. Unlike small 

hard platers, large facilities would not 

encounter significant difficulties in 

obtaining funds fo purchase and operate 

composite mesh-pad systems to replace 

existing packed-bed scrubbers. Thus, 

the cost of control for RA HI for large 

platers would be affordable and would 

not result in facility closures. 

Considering all these factors, the 

Administrator has selected RA III as die 

basis for the proposed MACT standard 

for large hard chromium electroplaters. 

This selection is based on consideration 

ofthe significant incremental reductions 

of chromium emissions that are 

achievable, the control costs, economic, 

and other environmental and energy 

impacts, all of which are reasonable. As 

discussed previously, the control cost is 

considered to be reasonable given the 

high toxicity of chromium emissions 

and the proximity of exposed 

populations to electroplating facilities. 

The cumulative impacts of RA IH on 

all hard chromium electroplaters 

provide further support for the 

decisions that were made separately for 

small and large platers. The economic 

impacts on small businesses are 

considered reasonable since the number 

of facilities that might close under RA 

IU is estimated to be less than 2 percent 

(20 to 28 out of 1,540 facilities). An 

estimated 99 percent emission reduction 

from all hard chromium electroplaters is 

estimated nationwide by requiring use 

of composite mesh-pad systems on all 

existing large hard chromium 

electroplaters and packed-bed scrubbers 

on small platers under RA III. If RA II 

were required, this number would be 

reduced to 98 percent reduction, and if 

RA I were required this estimate would 

be further reduced to 97 percent 

reduction. 

As discussed in section VI. A. of this 

preamble, the EPA developed 

nationwide emission and population 

exposure estimates associated with 

chromium electroplaters. EPA 

recognizes that there are a variety of 

factors that contribute to the 

uncertainties associated with the cancer 

risk assessments. However, despite 

these uncertainties, the estimates 

provide a frame of reference tiiat is 

useful for judging the risk reduction 

associated with the proposed standard. 

It is in this context that the following 

discussion is presented. 

Under baseline conditions (current 

control levels), hard chromium 

electroplaters could cause as many as 

100 increased cancer cases per year in 

the U.S. In addition, the EPA estimates 

that maximum, upper-bound individual 

risks could range from 4 chances in 

10,000 (4x10

 _4) for small platers to one 

chance in 100 (1x10-*) for large platers. 

The alternative selected for proposal, 

RA III, would reduce these estimates to 

1 cancer case per year and risks of 4 

chances in 1,000,000 (4xl0-«)for small 

platers and 3 chances in 100,000 

(3xl0-3)for large platers. These 

estimates are provided to give 

perspective to the potential impact of 

the proposed standards. For the 

complete picture of risk, one would also 

want to consider non-cancer risks, 

which are discussed in section VI. 6. 

e. Existing Decorative Chromium 

Electroplating—Chromic Acid Bath— 

MACT. The control technology that 

represents the MACT floor, i.e., the use 

of fume suppressants, is the highest 

level of control achievable by the 

subcategory and is the predominant 

form of control being used in the 

industry. Therefore, all existing 

decorative chromium electroplating 

sources using chromic acid baths would 

be required to meet an emission limit of 

0.003 mg/dscm (1.3x10-6 gr/dscf), 

which corresponds to the use of a fume 

suppressant, if an add-on air pollution 

device alone is used, or maintain a 

surface tension of no greater than 40 

dynes/cm (2.7x10-3 lbf/ft) (if wetting 

agents are used to control chromium 

emissions). 

f. Existing Decorative Chromium 

Electroplating—Trivalent Chromium 

Bath—MACT. There are no regulatory 

alternatives above the MACT floor. Due 

to the low emission potential and the 

absence of any existing control for these 

tanks, MACT for new and existing 

sources is the use of the trivalent 

chromium process, with monitoring of 

surface tension. All sources would be 

required to maintain a surface tension of 

no greater than 55 dynes/cm (3.8x10-3 

lbf/ft) or, if an air pollution control 

device alone is used, meet an emission 

limit of 0.048 mg/dscm (2.1x10-5 gr/ 

dscf). 

g. Existing Chromium Anodizing 

Tanks MACT. The control technology 

that represents the MACT floor, i.e., the 

use of fume suppressants, is the highest 

level of control achievable by the 

subcategory and is currently being used 

extensively at existing facilities to 

reduce chromium emissions. Therefore, 

all existing chromium anodizing tanks 

would be required to meet an emission 

limit of 0.003 mg/dscm (1.3x10-6 gr/ 

dscf) (if an add-on air pollution device 

alone is used) or maintain a surface 

tension of 40 dynes/cm (2.7x10-3 lbr/ft) 

(if wetting agents are used to control 

chromium emissions.) 
P.27 

65792 Federal Register / Vol'. 58} No; 240 / Thursday, DecembeE W, _993 / Proposed! Euies; 

Di Selection of the:Fbrmatof the'-

Proposed 'Standards. 

Concentration, in terms- of'mass of 

chromium- emitted per unit volume-of 

air, was determined to'Bathe-most 

appropriate-format? for the-stand'ards: Ih' 

selecting the format forthaproposed 

standards, the following factors were 

considered': (10'-The ability to ensure that 

the technology used'to-comply with-the 

standard is at least as effectivaasthe 

technology, upon which the standards: 

are based*, (2):_iB.abiHty to,ensure,tiiafc 

the technology selected-as the basis.of 

the standard can demonstrate 

compliance.in all-cases„i£uie.sy9tems 

are-operated' properly; and (3),the.cost, 

of determining.compliance.. 

Based on the. available emission test " 

data, it was determined that the inlet 

hexavarentchromium concentration 

levels increased as the current suppliadto the ebettoplatingbath increased, but 

the outlet concentrations1 (within a-given= 

control level) did; not vary significantly. 

Since tha outlet chromium 

concentration^ within' each classof 

control devices isrelatival^'constant, a 

determinatibnonthis basis regarding a 

control' system's performance can;be 

readily madei A-fbrmatbasedan. 

concentration would-also ensure that 

the technology, selectedias tha basis of 

the standards would be required-to meet 

the emissions.Umif.since.no data, 

overlaps, exist hetween__lasses of control 

devices. Ih.additihn, the outlet 

chromium concentration level is.easy to 

measure.and'the compUance test cost is. 

equal.to or less than-that of tha other 

formats considered. Therefore, aformat 

based on outlet concBntr_ti_rr was 

chosen to be the most appropriate 

format of the-standard. 

One concern1 with usihg-concentratibn 

as a format i's tiiat dilution of theexhaust gases-can be used to-circumvent 

the standards. Dilution ofthe gas streamr 

at the outlet ofthe-control-system is 

more of-a concern.thain any dilution; 

taking place at the inlet to the control 

systems since the control systems, 

operate,as constant outlet- devices.. 

However,, this concern,can be. addressed 

by a review of thatestdata and'.permit 

data from-agiven facility. The. air flow 

rata measured during testing should' 

approximate the design air flowrate for 

the control system-reported on the 

permit application. If the two values 

differ significantly, then an inspection 

of the controllsystem can be made to. 

determine if dilution airis being, 

introduced to the-system. 

Another concern-with-using; 

concentration as the format for the' 

standard was'that many decorativechromium and chromium anodizing 

tanks do: not hava ventilation systems: 

available..Th_s, it wouldbe. impossible.. 

to determine.the coneentration of the.-

emission.stieami.This; issue has bean. 

resolved!by aUowing;subfacilities to: 

demonstrate: comphance: by. measumiig: 

surface-tension!. ThaAgencybas) 

determined thata relationship) exists, 

between the.emission.concentraticn: that 

results from- applying' fuma suppressants 

and the surfaoa tension ofthe 

electroplating solution-. A chromic acid 

electroplating solution with: a surface 

tension less than orequal ta-40"dynes/ 

cmis-in compliance with-the emission 

limit. A trivalent chromium 

electropratihg-solUtioniwith a surface 

tension1 less than or-equal to'55 dynes// 

cm (SFiff^TO-—3". lbf/ft) isin compliancewith' tha emission- limit 

Other format options considered 

were: (l)':Thaperaentreduction;:(2)itlle 

process emission. rate(mass.of 

chromium emitted per unit of 

production (as-measured by the current 

input to the electroplatingtank)';-and (3) 

the mass emission rata (the mass of 

cBromium emitted: per unit of time). 

Percent reduction is determined from 

the inlet and'outlet:mass:emission. rates. 

As-stated: previously,, the; outlet' 

chromium: concentration is relatively 

constant for a given- class of control 

equipment. Therefore, percent reduction 

i's-not a good' indicator of performance 

because of its dependency on the;inlet 

loading to thecontrol devices Theiuse of 

percent reduction' as tha format ofthe. 

standards wouldnot ensurethe use:of 

tha technology selected' as; tha basis for 

the standards because of the data 

overlaps that exist between, elassesof 

control devices. Thesedato overlhps: 

exist because-of variations in tha inlet 

loadingsamong:facilities. In addition, 

inlet testing ofthe control device-is not 

always feasible; especially at existing 

facilities, and the-GompUance>cost is 

substantially-higher than that for the 

other formatsbecausetestihg'ofthe 

control device inlet and outlet is 

required. Therefore, the* dependency on 

inlet loadings; the higher comphance 

cost, and potential inlet testing 

problems'makapercent reduction 

unacceptable asthe format of'the^ 

standards. 

The process emission-rata is based! on. 

the outlet massennssion rate'and tha 

current suppUed to the electroplating' 

tank. As noted above, the outletmass 

emission rate varies depending' on tha 

chromium concentration and the 

exhaust gas flow rata. Since the outlet 

concentration levels dOmot vary with, 

tha current lbadmg to; the electroplating 

tank, fetihties>t_.at operateiat high 

current loadings would'have a much 

lbwarprocess emission ratathan: 

facilities, thataparate a_lowc_r____ 

lbadings. evan'tkoughbolhi facilities 

hase;_ppi__Bdt__o____8ti3fc5___logy and! 

may be (^ntrolifid'.twthesBmaermssions: 

level. Conversely; facilities that have'alowprocessemissionrate could'.have 

hig_OTemi3m'_nsthan.intandedbythestandardabecausa of a high inlet; 

loading: (high c_rrentloading)jto;_iecontrol device: Even though-tits-cost of 

compUanca is:equal to airless thani that 

for other format options;, tha processemission rata was: not selected, as. the: 

formafeof tha standards:. 

The mass-emission rate varies; 

depending, upon tha chromium-, 

concentration; and the'exhaust gas; flow, 

rate. The mass emission rataiseasy tomeasure,, and tha compUance- costs: are; 

equal to. or less __u_that.f6r the other 

format options. However; since: the 

outlBt.chromium: concentration is? fairlyindependent of thaproduction rate 

(inlet cnirenClaadiiig) of tha facility,, themass emission rate variessaccordingto; 

the exhaust gas.flow rate which is a 

function, of the size ofthe facility-

(numherof electroplating-tanks). This 

dependan_yrasultsin.data:overlaps, 

between thaclasses of control devices. 

To eUminatB;t_BSB;overlaps;. multiple. 

emi_simrliimte;wcndd.b»req_ired to. 

accommodate tha size-variation among 

the facilities..Therefore,.amass-emission: 

rate limitation wasno7tselected.as:theformat, of the standardi. 

E. Selection offthe Emission IJmits 

This, section presents, tha emissions 

data-used to-determine. tha emission 

limits for the-technologies selected as. 

the basis of the-standard's. For hard 

chromium tanks, packedrbedscrubbers 

and composite mesh-pad systems.were 

selected, as the basis ofthe standards.. 

Far-decorative chromium tanks-,, 

chemiGalfume suppressants or tha 

trivalent chromium process formstha 

basis of the standards. ChemieaL fumesuppressants also form tha basis for the 

standard: fbranodizina tanks. 

All of tha emission Umita presented 

below.-are in terms of mg;of total 

chromium per dscm: of exhaust air. 

Dufi_ig;the:ea_ly part of the- emission! 

test.program,bot_i,hexavalent and- total 

chromium were-measured:at each-site. 

The resultsof these tests:todicate that, 

considering, the precision of tha 

sampling and analyticalmethDdsused, 

the hexavalent and tDtal chromium, 

levels were essentialiy tiie. same (for all 

tanks;usmg7achrQTnic.acid. 

electooplating bath, solution). There fare, 

itcan> be: presumed that aliofthe 

chromiumi was in. the: hexavalent form;, 

which would be: expected; given the: fact 

that chromic acid is a-hexavalent 

compound of chromium. For these. 
P.28 

Fe«_B-__ magnate. / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules (35793 

reasons, total chromium analyses were 

discontinued for tha remainder of the 

tests. The hexavalent chromium 

concentrations* however, were assumed 

to equal the total chromium 

concentrations, and all of the emission 

Hmits are expressed in terms of total 

chromium. In addition to the reasons 

cited above, the analytical method for 

total chromium is less expansive than 

that for hexavalent chromium, and most 

laboratories can perform total chromium 

analyses, but fewer laboratories perform 

hexavalent chromium analyses. 

The numerical emission limit 

associated with packed-bed scrubbers is 

0.03 miUigram of total chromium per 

dry standard cubic meter (1.3x10-3 gr/ 

dscf) of exhaust air. The numerical 

emission limit associated with 

composite mesh pad systems, is 0.013 

mg/dscm (5.7x10-6 gr/dscf) of exhaust 

air. A numerical Umit of 0.003 mg/dscm 

(1.3x10-6 gr/dscf) of exhaust air was 

selected for chemical fume suppressants 

usage. A total chromium emission Umit 

of 0.048 mg/dscm (2.1x10-3 gr/dscf) of 

exhaust air was estabUshed for the 

trivalent chromium process. 

Based on available emissions test data 

and considering factors relevant to the 

level of controlled emissions, the 

Administrator has determined that the 

proposed emission limits are achievable 

in aU circumstances that can be 

reasonably foreseen. A summary of the 

factors considered in the selection of the 

emission limits is presented in the 

discussion of emission test data below. 

Complete discussions are presented in 

chapter •. ofthe BID and in the New 

Technology Report (see A0_J3_SS_§). 

. Emission tests were conducted af 13 

hard chromium electroplating faciUties 

and 3 decorative chromium 

electroplating facilities. Ofthe 13 hard 

chromium electroplating faciUties 

where tests were conducted, 3 used 

chevron-blade eUminators, 3 used meshpad mist eUminators, three used 

packed-bed scrubbers, 3 used composite 

mesh-pads in series, and 1 used a 

packed-bed scrubber in conjunction 

with a composite mesh-pad At two of 

the decorative chromium faciUties 

tested, uncontrolled emission levels 

were quantified, and the performance of 

chemical fume suppressants was 

evaluated. At the third decorative 

chromium faciUty, the chromium 

emissions from a trivalent chromium 

electroplating process were evaluated. 

Additionaldata were collected from 

hard and decorative chromium 

electroplating faciUties but were 

excluded from the data base because of 

process upset conditions, control 

equipment malfunctions, or procedural 

discrepancies with EPA test methods 

The rationale for excluding tiiese data is 

presented in Appendix D ofthe BED. 

No chromium anodizing faciUties 

were tested. However, a mass balance 

was performed to quantify uncontrolled 

emission levels from a scrubber used to 

control chromium emissions from a 

chromic acid anodizing tank. (For 

further information on this estimating 

procedure and the calculations 

involved, refer to Chapter 3 and 

Appendix C ofthe BID.) 

The emissions data obtained on 

packed-bed scrubbars operating with 

periodic or continuous washdown and 

typical chromic acid concentrations in 

the scrubber water (0 to 29.9 g/L [0 to 

4 oz/gal]) indicated chromium 

emissions ranging from 0.020 to 0.028 

mg/dscm (8.7x10-6 to 1.2x10-s gr/dscf) 

with an average concentration of 0.024 

mg/dscm (l.lxlO-s gr/dscf). Using the 

methodology presented in ssction IK of 

this preamble, packed-bed scrubbers 

were determined to be the MACT floor 

for hard chromium electroplating tanks. 

For packed-bed scrubbars, a total 

chromium emission Umit of 0.03 mg/ 

dscm (1.3x10-3 gr/dscf) was selected 

because this was the highest value 

obtained during any of the test runs 

(0.028 mg/dscm rounded to 0.03 mg/ 

dscm). Based on tests the Agency has 

conducted on mesh-pad mist 

eliminators used af some hard 

chromium electroplating tanks, this 

emission Umit could probably also be 

achieved by those devices. 

The emissions data obtained on 

composite mesh-pads, either used in 

series or in conjunction with a packedbed scrubber, indicated total chromium 

emissions ranging from 0.004 to 0.013 

mg/dscm (1.7x10-6 to 5.7x10-«gr/ 

dscf), with an average concentration of 

0.009 mg/dscm (3.9x10-6 gr/dscf). A 

total chromium emission limit of 0.013 

mg/dscm (5.7x10-6 gr/dscf) was 

selected for composite mesh-pads 

because this value was the highest 

obtained during any of the test runs. 

Two types of chemical fume 

suppressants ware tested at decorative 

chromium electroplating facilities using 

a chromic acid bath—a foam blanket 

and a combination foam blanket and 

wetting agent. The only data considered 

in estabhshing the emission Umit were 

those for the combination foam blanket 

and wetting agent. The emissions data 

based on the use of a foam blanket alone 

were excluded because this control 

technique was considered to ba less 

effective than ths combination foam 

blanket and wetting agent, as stated in 

section VLB.5. The test data for 

chemical fume suppressants indicated 

chromium emissions ranging from 0.001 

to 0.003 mg/dscm (-8.4x10-? to 1.3x10-6 

gr/dscf), with an average concentration 

of 0.002 mg/dscm (8.7x10-7 gr/dscf). 

The total chromium amission Umit 

selected for chemical fume suppressants 

is 0.003 mg/dscm (1.3x10-6 gr/dscf), 

which was the highest value obtained 

during the test runs. 

Source testing of a decorative 

chromium electroplating operation that 

uses a trivalent chromium electroplating 

process was also conducted by EPA. 

Total chromium emissions from this 

operation ranged from 0.013 to 0.048 

mg/dscm (5.7x10-6 to 2.lxl0-sgr/ 

dscf), with an average total chromium 

concentration of 0.027 mg/dscm 

(1.2x10-3 gr/dscf). The emission limit 

that was selected for these tanks is 0.048 

mg/dscm (2.1xl0-s gr/dscf). which was 

the highest value obtained during any of 

the test runs. 

Some facilities that use chemical 

fume suppressants in their 

electroplating or anodizing baths do not 

have ventilation systems; thus, omission 

testing of these systems is not possible. 

The Agency has determined that 

another parameter, surface tension, can 

be measured to determine compUance 

with the emission limits. This alternate 

parameter can be used when wettingagent-type fume suppressants or 

combination foam-blanket/wettingagent-type fume suppressants are used 

and a ventilation system is not present. 

If a wetting agent or a combination foam 

blanket/wetting agent is used to control 

emissions, then the surface tension of 

the electroplating or anodizing bath 

must be monitored by using a 

stalagmometer to ensure that the surface 

tension is at or below 40 dynes/cm 

(2.7x10-3 lbf/ft). 

If a trivalent chromium electroplating 

process is used to control emissions, 

then the surface tension of the 

electroplating bath must be monitored 

by using a stalagmometer or tensiometer 

to ensure that the surface tension is at 

or below 55 dynes/cm (3.8x10-3 lbf/ft). 

In both cases, the surface tension should 

be measured at least once every 4 hours. 

F. Selection of Definition of Source 

The choice of an affected source 

influences possible reconstruction and 

modification impacts of the standards. It 

also determines ths point af which the 

addition or replacement of individual 

emission sources (i.e., electroplating or 

anodizing tanks) results in a "new" 

source. Section 112(a)(3) ofthe Act 

defines "stationary source" as having 

the same meaning as that given in 

section 111(a) of the Act, where 

"stationary source" is defined as "any 

building, structure, facility, or 

installation which emits or may emit 

any air pollutant." Most industrial 
65794 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

plants consist of numerous pieces or 

groups of equipment that emit HAP and 

that may be viewed as "sources." The 

EPA, therefore, uses the term "affected 

source" to designate the equipment 

within a particular kind of plant that is 

chosen as the "source" covered by a 

given standard. 

1. Reconstruction Considerations 

In designating the affected source, 

EPA determines which piece or group of 

equipment is the appropriate unit (the 

affected source) for emission standards 

in the particular conte5rt involved. The 

determination is made in light of the 

terms and purpose of section 112. One 

major consideration is that a narrow 

designation of source usually brings 

replacement equipment under new 

source MACT sooner. 

If, for example, an entire plant is 

designated as the affected source, the 

new source MACT would cover no part 

of the plant unless the replacement 

causes the entire plant to be 

"reconstructed." Reconstruction, as 

defined in the proposed § 63.5, means 

the replacement of the components of 

an affected source to such an extent 

that: (1) The fixed capital cost of the 

new components exceeds 50 percent of 

the fixed capital cost that would be 

required to construct a comparable new 

source, and (2) it is technologically and 

economically feasible for the 

reconstructed source to meet the 

promulgated emission standards 

established by the Administrator 

pursuant to section 112 ofthe Acts 

Upon reconstruction, an affected major 

source is subject to relevant standards 

for new sources, including compliance 

dates, irrespective of any change in 

emissions of HAP from that source. 

Major sources are also subject to the 

preconstruction and review 

requirements provided in § 63.5, 

provided the source commenced 

reconstruction after proposal but does 

not start operation before promulgation 

of the final standards. 

On the other hand, if each piece of 

equipment (i.e., each electroplating or 

anodizing tank) is designated as an 

affected source, then any single tank can 

be subject to the reconstruction 

provision (if the tank is located at a 

major source). A narrow designation of 

the affected source would ensure that 

the standards would cover 

reconstructed emissions sources (i.e., 

individual tanks) with new source 

MACT with each replacement or 

reconstruction of a tank. A broader 

designation of the affected source may 

be appropriate if it would: (1) Result in 

"Ibid. 

equal or greater emission reduction than 

would a narrow designation or (2) avoid 

inordinate costs or other adverse 

impacts. 

2. Modification Considerations 

According to section 112(a)(5), 

"modification" means any pnysical 

change in, or change in the method of 

operation of, a major source which 

increases the actual emissions of any 

hazardous air pollutant emitted by such 

source by more than a de minimis 

amount or which results in the emission 

of any hazardous air pollutant not 

previously emitted by more than a de 

minimis amount. Modified sources are 

subject to section 112(g) provisions, 

which prevent any person from 

modifying a major source of HAP unless 

the MACT emission limitation for 

e:xisting sources will be met. If 

modifications of major sources occur 

prior to the establishment of final rules 

under section 112(d), the States are 

required to estabUsh MACT for the 

modified sources on a case-by-case 

basis. Therefore, until promulgation, the 

source designation will be determined 

on a case-by-case basis by the permitting 

authority. 

The EPA has reserved space within 

the proposed General Provisions for 

provisions related to section 112(g) that 

will be added in a separate rulemaking. 

Until EPA guidance on this issue is 

available, it is difficult to project the 

potential impact an affected source 

designation could have on the industry 

that is the subject of today's rulemaking. 

However, since only major sources are 

affected under section 112(g), the 

impact is probably limited because the 

majority of electroplating facilities will 

be considered area sources. 

3. Affected Source Definitions 

There are three alternative 

designations that could be applied to 

the source category. The narrowest 

designation would be each individual 

electroplating or anodizing tank. The 

broadest designation would be the 

group of electroplating or anodizing 

tanks at each facility that are covered by 

the standards. A third possibility is the 

designation of groups of electroplating 

tanks by category or subcategory; in 

other words, affected sources would be: 

(1) All hard chromium electroplating 

tanks, (2) all decorative chromium 

electroplating tanks using chromic acid 

baths, (3) all decorative chromium 

electroplating tanks using trivalent 

chromium baths, and (4) all chromic 

acid anodizing tanks. 

With the exception of hard chromium 

electroplating tanks, the new and 

existing source MACT is the same for 

the remaining sources. In addition, the 

preconstruction review requirements for 

decorative platers and anodizers should 

be relatively easy to meet because of the 

relative simplicity and availability of 

the means of control, i.e., the use of 

fume suppressants or, as applicable, the 

use of a trivalent chromium 

electroplating bath. However, because 

new source MACT is more stringent 

than existing source MACT for small 

hard chromium electroplaters and 

because the emission limits assume the 

use of add-on control devices, the 

impact of an affected source designation 

is more significant to hard chromium 

electroplaters. Therefore, EPA based the 

designation decision on the potential 

impacts to this source category. 

The EPA is proposing to define the 

affected source in terms of individual 

tanks. The narrow designation 

maximizes the potential emission 

reduction from the source categories. 

Defining the affected source as an 

individual taijk ensures that new source 

MACT is applied to new hard 

chromium electroplating tanks. 

However, if a new tank is added at an 

existing source, emissions from the new 

tank could be ducted to an existing 

control device on site as long as the 

emissions from the new tank do not 

exceed the required emission levels. If 

the tank is added at a major source, the 

preconstruction review provisions 

would be triggered. The preconstruction 

review requirements are extensive in 

that the source would be required to 

perform an emission test to establish the 

emission rate eTxpected. However, 

because these provisions only apply to 

major sources and this industry is 

comprised largely of area sources, the 

potential impact of this scenario is 

small. 

As indicated by the discussion above, 

EPA believes that a narrow definition of 

source based on individual tanks 

represents the most reasonable approach 

given typical plant design and that the 

additional costs of this approach are 

generally minimal. EPA requests 

comments on the effect of adopting a 

narrow definition of source and on its 

proposal to define the affected source as 

each individual tank. 

G. Selection of Monitoring Requirements 

The amended Act added paragraph (3) 

to section 114(c). This paragraph 

requires enhanced monitoring of 

stationary sources (or possibly other 

sources) to indicate the compliance 

status of the source, and whether 

compliance is continuous or 

intermittent. Today's rulemaking also 

identifies monitoring parameters that 

indicate proper operation and 
P.30 

m I Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules (5572)5 

maintenance (O&M) of the control 

device. The following paragraphs 

describe the enhanced compliance 

monitoring and the O&M monitoring, 

and the bases for their selection. 

1. Enhanced CompUance Monitoring 

In accordance with § 63.7 of the 

General Provisions for this part, each 

source subject to these standards would 

be required to conduct an initial 

performance test7 The Act requires that 

after the initial performance test, the 

compliance status ofthe source must be 

demonstrated. For this source category, 

EPA has decided that certain operating 

parameters should be monitored to 

indicate ongoing compUance with the 

emission Umit. 

For packed-bed scrubbers and 

composite mesh-pads used in 

conjunction with packed-bed scrubbers, 

the gas velocity at the inlet of the device 

and the chromium concentration of the 

scrubber water have been selected as 

those operating parameters that are most 

indicative of control device 

performance. (The importance of these 

parameters was discussed in section 

V.B.) Therefore, during the initial 

performance test, the owner or operator 

would be required to set the range of 

values for gas velocity at tha inlet to the 

control device that corresponds to 

compUance with the emission Umit set 

by the proposed standards. These 

standards would require daily 

measurement of gas velocity to ensure 

compliance with the emission Umit. 

Operation of the control device outside 

of the gas velocity range estabUshed 

during the performance test would 

constitute noncompUance with the 

emission Umit. Additionally, faciUties 

using packed-bed scrubbers would be 

required to measure the scrubber water 

concentration once daily. If the scrubber 

water concentration exceeds 45 g/L (6 

oz/gal), the owner or operator would not 

be in compUance with the emission 

Umit. As an alternative to compUance 

with this scrubber water concentration, 

the owner or operator may estabUsh a 

maximum scrubber water concentration 

jthat corresponds to compUance with the 

emission Umit during the initial 

performance test. Because gas velocity 

and scrubber water concentration are 

not highly variable when the add-on 

control device is properly operated and 

maintained, the EPA beheves that a 

daily measurement of gas velocity and 

scrubber water concentration is 

sufficient to indicate continued 

compUance with the emission Umit. 

Violation of either of these operating 

'Ibid. 

parameters would constitute 

noncompUance with tha emission limit. 

For mesh-pad mist eliminators (that 

meet the total chromium emission Umit 

of 0.03 mg/dscm (1.3x10-5 gr/dscf)), 

and for composite mesh-pads, ths daily 

measurement of gas velocity alone 

would indicate compliance or 

noncompUance with tha emission limit. 

The operating parameter value for gas 

velocity that corresponds to compUance 

with the emission limit would bs 

established during the initial 

performance test. 

2. Alternate CompUance Monitoring for 

Sources Using Fume Suppressants 

For tanks that comply with the 

standards through the use of chemical 

fume suppressants, ths measurement of 

surface tension every 4 hours would 

indicate comphance or noncompUance 

with the standards. Decorative 

chromium tanks using a chromic acid 

electroplating process would be 

required to maintain a surface tension 

no greater than 40 dynes/cm (2.7x10-3 

lbf/ft); those using a trivalent chromium 

electroplating process would be 

required to maintain a surface tension 

no greater than 55 dynas/cm (3.8x10-3 

lbf/ft). Operation ofthe electroplating 

baths at surface tensions greater than the 

values identified in these standards 

would indicate noncompliance with the 

emission Umit. Owners or operators 

who choose to comply with these 

surface tension hmits would not be 

required to conduct an initial 

performance test. Those decorative 

chromium tanks that use a chemical 

fume suppressant in conjunction with a 

control device may conduct an initial 

performance test to establish an 

alternative surface tension valua that 

corresponds to compliance with ths 

emission limit. 

The Agency has determined that 

measurement of the surface tension of 

the bath (using a stalagmometer or 

tensiometer) at least once every 4 hours 

during operation of ths tank would be 

sufficient to ensure continuous 

compliance with the emission limit. The 

time interval specified for measuring the 

surface tension is based on the time 

interval at which additions of wetting 

agent were required during the emission 

test program conducted to develop these 

standards. The time intervals for 

addition requirements would vary with 

each operation (e.g., size of tank, current 

density, configuration of parts, etc.). 

The owner or operator of a tank that 

uses a foam blanket alone fo comply 

with the standards would ba required to 

conduct an initial performance test to 

confirm that the emission Umit of 0.003 

mg/dscm (1.3x10-a gr/dscf) is being 

met. For ongoing compliance, ths owner 

or operator would be required to 

measure and record the foam blanket 

thickness at least once every hour 

during operation of the tank. Qparatior. 

ofthe electroplating tank at a foam 

blanket thickness less than the level 

established during the performance test 

or 2.54 cm (1 in.) (whichever is greater), 

would constitute noncompliance with 

the standards. 

The owner or operator of a tank that 

uses a trivalent chromium electroplating 

bath would be required by the standard 

to monitor the surface tension using a 

stalagmometer every 4 hours. Operation 

of the electroplating tank at surface 

tensions above 55 dynes/cm (3.8x10-3 

lbf/ft) would constitute noncompliance 

with the standards. 

3. Operation and Maintenance 

Monitoring 

Section 63.6(e) of the proposed 

General Provisions identifios operation 

and maintenance requirements, which 

include the preparation of a startup, 

shutdown, and malfunction plan.a In 

addition, specific operation and 

maintenance monitoring would be 

required by the proposed standards. 

An owner or operator who operates a 

control device to ensure compliance 

with the standards would bs required to 

prepare an operation and maintenance 

plan that must include, at a minimum, 

a standardized checklist to document 

the operation and maintenance of the 

equipment, a systematic procedure for 

identifying and reporting malfunctions, 

and procedures to ensure that 

equipment or process malfunctions due 

to poor maintenance or other 

preventable conditions do not occur. 

Owners or operators of decorative 

chromium electroplating tanks who 

choose to demonstrate compliance by 

adhering to the surface tension hmits 

required by these standards (not those 

established during an initial 

performance test) would not be subject 

to the operation and maintenance 

monitoring requirements. Specific 

requirements for the operation and 

maintenance plan are in §63.115 ofthe 

proposed standards. 

H. Selection of Test Methods 

Test Methods 308 and 306A, 

"Determination of Chromium Emissions 

from Decorative and Hard Chromium 

Electroplating and Anodizing 

Operations," are the proposed methods 

for determining compliance with the 

emission standards. Test Method 306B, 

"Surface Tension Measurement and 

Recordkeeping for Tanks used at 

•Ibid. 
P.31 

65796 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

Chromium Electroplating and 

Anodizing FaciUties," is the proposed 

method for monitoring surface tension 

at decorative chromium electroplating 

and chromic acid anodizing facilities. 

All three methods are proposed for 

addition to Appendix A of 40 CFR part 

63. 

Methods 306 and 306A were 

developed for measurement of 

chromium emissions from chromium 

electroplating faciUties. Method 306 is 

based on Method 5 (40 CFR part 60. 

Appendix A) and utilizes isokinetic 

sampUng. The major modifications to 

Method 5 to yield Method 306 include 

elimination of the filter, use of an 

alkaline impinger reagent for sample 

collection, and sample analysis by the 

tester's choice of graphite furnace 

atomic absorption spectrometry or 

inductively-coupled argon plasma 

emission spectrometry. Both analytical 

techniques produce results for the total 

chromium concentration of the emission 

sample. 

Method 306A is a simplified, constant 

sampUng rate method for measurement 

of chromium emission from 

electroplating faciUties, which offers 

owners and operators a less eTxpensive 

means to demonstrate compliance than 

Method 306. Collection of a 

representative sample without 

isokinetic sampling is achieved by 

varying the sampUng time at each 

traverse point and limiting the particle 

size ofthe sampled emissions to 10 

micrometers. Sample analysis for 

Method 306A is identical to that for 

Method 306. When correctly appUed, 

the precision and bias of Method 306A 

have been demonstrated to be 

comparable to those of Method 306. 

Method 306B provides procedures for 

measuring the surface tension of plating 

or anodizing tank baths when a wetting 

agent is used for emission control. The 

method offers the option for use of two 

generally accepted surface tension 

measurement devices, a stalagmometer 

or a tensiometer. 

J. Selection of Reporting and 

Recordkeeping Requirements 

The owner or operator of any source 

subject to these standards would be 

required to fulfill all reporting 

requirements outlined in 40 CFR 63.10.9 

An owner or operator of a source who 

uses an add-on air pollution control 

device to meet these standards would 

also be required to maintain records of 

daily and monthly inspections, daily gas 

velocity readings, daily scrubber water 

concentrations, daily washdowns, daily 

pressure drop readings, and any 

"Ibid. 

emission tests at the facility. These 

records should be maintained for a 

minimum of 5 years. Each inspection 

record would identify the device 

inspected and include the following: the 

date and approximate time of 

inspection, a brief description of the 

working condition of the device during 

the inspection, the gas velocity, the 

scrubber water concentration, the 

pressure drop, and any actions taken to 

correct deficiencies found during the 

inspection. Each record of washdown 

would identify the device and include 

the date, approximate time, and 

duration ofthe washdown. 

An owner or operator of a source who 

uses a fume suppressant to comply with 

these standards would be required to 

maintain the following records at the 

faciUty for at least 5 years: (1) The 

amounts of fume suppressants 

purchased (invoices); (2) the frequency 

of maintenance additions; (3) the 

amount of material added during each 

maintenance addition; (4) the surface 

tension of the bath or the foam blanket 

thickness; and (5) any emission tests to 

assure compUance with the standard. 

Each record of a surface tension 

measurement would identify the tank 

and include the date, approximate time, 

measured surface tension, and whether 

any additions were made to the bath. 

Each record of a foam blanket thickness 

measurement would be required to 

identify the tank and include the date, 

approximate time, measured thickness, 

and whether any additions were made 

to the bath. If an addition was made, the 

amount of material added would also be 

recorded. 

An owner or operator of a source who 

uses a trivalent chromium electroplating 

process would be required to maintain 

the following records at the faciUty for 

at least 5 years: (1) The amount of bath 

additive containing wetting agent 

purchased (invoices); (2) the surface 

tension ofthe bath; and (3) any emission 

tests to assure compUance with the 

standard. Each record of a surface 

tension measurement would identify the 

tank and include the date, approximate 

time, measured surface tension, and 

whether any additions were made to the 

bath. 

All records of inspections, 

washdowns, pressure drop readings, 

emission tests, foam blanket and surface 

tension measurements, frequency of 

fume suppressant maintenance 

additions, the amount of fume 

suppressant added during each 

maintenance addition, and purchases of 

fume suppressants would be maintained 

at the faciUty for a minimum of 5 years. 

The operation and maintenance plan 

(associated with add-on pollution 

control devices) would be maintained at 

the faciUty for the life ofthe device. The 

Administrator beheves that the above 

reporting and recordkeeping 

requirements are adequate to ensure that 

owners or operators are complying with 

the provisions of the proposed 

standards. 

/. Operating Permit Program 

Under the operating permit 

regulations codified at 40 CFR part 70, 

any source that is a major source under 

the Act or any nonmajor source subject 

to a standard under sections 111 or 112 

ofthe Act must obtain an operating 

permit. (See § 70.3(a)(1).) The part 70 

regulations also provide that a State 

may, at its discretion, defer all nonmajor 

sources from the obligation to obtain a 

part 70 permit until such time as the 

EPA finishes a rulemaking regarding the 

applicability of the part 70 program to 

nonmajor sources. Part 70 further 

provides that, for nonmajor sources 

subject to a future standard promulgated 

under section 111 or 112, "*• * * the 

Administrator will determine whether 

to exempt any or all such apphcable 

sources from the requirements to obtain 

a part 70 permit at the time that the new 

standard is promulgated." (See § 70.3(b) 

(l)and{2).) 

The proposed rule for chromium 

electroplating and anodizing tanks 

would not exempt area sources from 

E

ermitting requirements. The EPA 

eUeves that permitting these nonmajor 

sources will enhance the 

implementation and enforcement of the 

rule by clarifying how the rule applies 

to a particular source, and how relevant 

parts ofthe to be promulgated general 

provisions apply to chromium 

electroplating and anodizing tanks. The 

proposed general provisions are generic 

requirements that sources subject to 

section 112 standards must meet.10 

However, under the existing 

provisions of part 70, States may choose 

to defer the obligation of all nonmajor 

sources to obtain a permit until the EPA 

"completes a rulemaking to determine 

how the program should be structured 

for nonmajor sources and the 

appropriateness of any permanent 

exemptions* * *." In promulgating the 

permits rule, the EPA committed to 

complete that rulemaking within 5 years 

after the approval ofthe first State part 

70 program that defers permitting of 

nonmajor sources. 

The EPA believes, for the same 

reasons stated in the preamble to the 

operating permits rule, that the benefits 

to be gained from the permitting of 

nonmajor sources subject to this 

io Ibid. 
P.32 

BgisteF / Vol..58, No. 240 / Thursday, December 16, 1993 / Proposed Rules ©57-7 

proposed rule are not Ukely to accrue 

during the early, stages of the permit 

program when permitting authorities 

will be occupied with the task of issuing 

permits to major sources. Once this task 

is complete, however, permitting 

authorities should be able fo process 

permits for nonmajor sources subject to 

this rule on a relatively expedited basis. 

This expedited review should be the 

case, in part, because of the presumptive 

suitability of these sources for general 

permits. 

K. Solicitation of Comments 

The Administrator specifically 

requests comments on the topics 

discussed in this section. Commenters 

should provide available data and 

rationale to support their comments on 

each topic. 

1. Surface Tension Limit for Decorative 

Chromium Electroplating Tanks Using a 

Trivalent Chromium Electroplating 

Process 

The EPA specifically requests 

comments on the proposed surface 

tension limit of 55 dynes/cm (3.8x10-* 

lbf/ft) for those decorative chromium 

electroplating tanks using a trivalent 

chromium electroplating process. This 

limit was selected by EPA based on the 

test data available (see section IV.C.2.c), 

which indicate that the value of surface 

tension achievable in a trivalent 

chromium electroplating bath is a 

majdmum of 55 dynes/cm (3.8x10-3 lbf/ 

ft). The surface tension achievable in a 

given trivalent chromium bath will be 

dependent on the specific chemistry of 

that bath. Therefore, a lower surface 

tension may be achievable. 

Alternatively, a source may have 

difficulty lowering the surface tension 

of its trivalent chromium electroplating 

bath to 55 dynes/cm (3.8x10-3 lbf/ft). 

Although the available data indicate 

that a value of 55 dynes/cm (3.8x10-3 

lbf/ft) is the most reasonable fo select as. 

the maximum surface tension of a 

trivalent chromium electroplating bath, 

the Administrator welcomes data that 

indicate that an alternate surface tension 

Umit is more appropriate. 

2. Use of Trivalent Chromium 

Electroplating Process 

As discussed in sections V.A.2 and 

V.B.5, the trivalent chromium 

electroplating process is considered an 

effective pollution prevention 

technique. The use of a trivalent 

chromium electroplating process results 

in less total chromium in process 

wastewaters and less sludge generation 

than would result from a chromic acid 

electroplating process. Also, hexavalent 

chromium emissions are reduced by 

greater than 99 percent when the 

trivalent chromium electroplating 

process is used instead of an 

uncontrolled chromic acid bath. 

During development of the proposed 

standards, EPA considered requiring the 

trivalent chromium electroplating 

process as a control technique for new 

decorative chromium electroplating 

tanks because of its pollution 

prevention aspects and its low 

hexavalent chromium emissions. 

However, results of a source test 

indicated that total chromium emissions 

were greater than those from a wellcontrolled chromic acid bath even 

though hexavalent chromium emissions 

were much lower. These Umited source 

test data do not support requiring the 

trivalent chromium electroplating 

process for all new decorative 

chromium electroplating tanks. 

Therefore, new decorative chromium 

electroplating sources would be allowed 

by the proposed rule to use either the 

chromic acid process with fume 

suppressants and bath surface tension 

monitoring or the trivalent process with 

bath surface tension measuring. 

However, the EPA encourages new 

decorative chromium electroplating 

sources to use the trivalent process 

because of its overall multi-media 

benefits. The Administrator requests 

comments on whether the trivalent 

process should be required for new 

sources in the final rule and welcomes 

any data related fo emissions of total 

and hexavalent chromium from the use 

of a trivalent chromium electroplating 

process. 

3. Proposed Standards for Small Hard 

Chromium Electroplaters 

Comments are specifically requested 

on the level of the proposed standards 

for small hard chromium electroplaters 

[0.03 mg/dscm (1.3x10-3 gr/dscf)]. 

Comments should indicate whether the 

proposed level is appropriate given tho 

consideration of factors discussed in 

section VI.C.5 of this preamble and why. 

4. Requirements for Recirculating 

Scrubber Water 

In considering the cross-media 

impacts ofthe proposed standards, EPA 

identified a potential need for further 

regulation: the wastewater from packedbed scrubbers and composite mesh pads 

used fo comply with the emission 

limits. To minimize the water pollution 

impact from these control devices, if 

may be appropriate to require that the 

wastewater be routed back fo the 

chromium bath in one of two ways 

before its eventual discharge: (1) The 

rule could require that packed-bed 

scrubber wafer be recirculated within 

the control device until the chromium 

concentration reaches a certain level 

(pursuant to the concentration limits in 

the proposed rule) and then the water 

could be reused in the bath or 

discharged; or (2) the rule could require 

that scrubber water be recirculated and 

routed back to the bath as makeup water 

(in the case of composite mesh pads, 

there is only washdown water; this 

would have to be sent back to the bath). 

Under the latter option, discharge of the 

wastewater would not be allowed. 

The Agency has identified several 

issues associated with these 

requirements. First, there is some 

uncertainty as to whether EPA has 

authority under section 112(d) of the 

Act to set a zero discharge requirement 

for wastewater from control devices. 

This uncertainty exists because a zero 

wastewater discharge requirement 

would not result in an air emission 

reduction (chromium in wastewater will 

not become airborne) even though it 

will ensure minimal water pollution 

impacts. Second, some sources have 

indicated that they cannot route 

scrubber or washdown water back to the 

plating tanks because there is too much 

metal contamination. This is especially 

the case with older control devices; the 

materials of construction could lead to 

increased concentrations of iron and 

lead in the water. Third, sources will 

already have an incentive to recycle and 

reuse wastewater as much as possible to 

avoid costly treatment of wastewater 

prior to discharge. 

Due fo these issues, the proposed rule 

does not address wastewater discharges. 

However, EPA specifically requests 

comments on limiting or prohibiting 

wastewater discharges in the standard 

and any data on why this is or is not 

reasonable. 

VD. Administrative Requirements 

A. Public Hearing 

A public hearing will be held, if 

requested, fo discuss the proposed 

standards in accordance with section 

307(d)(5) ofthe Act. Persons wishing to 

make oral presentation on the proposed 

standards for chromium emissions from 

hard and decorative chromium 

electroplating and chromium anodizing 

tanks should contact EPA at the address 

given in the ADDRESSES section of this 

f

ireamble. Oral presentations will be 

imited to 15 minutes each. Any 

member of the public may file a written 

statement before, during, or within 30 

days after the hearing. Written 

statements should be addressed to the 

Air Docket Section address given in the 

ADDRESSES section of this preamble, and 

should refer to Docket No. A-88-02. 
65798 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

A verbatim transcript of the hearing 

and written statements will be available 

for public inspection and copying 

during normal working hours at EPA's 

Air Docket Section in Washington, DC 

(see ADDRESSES section of this 

preamble). 

B. Docket 

The docket is an organized and 

complete file of all the information 

submitted to or otherwise considered by 

EPA in the development of this 

proposed rulemaking. The principal 

purposes of the docket are: (1) To allow 

interested parties to readily identify and 

locate documents so that they can 

intelligently and effectively participate 

in the rulemaking process, and (2) to 

serve as the record in case of judicial 

review [except for interagency review 

materials (section 307(d)(7)(A))]. 

C Executive Order 12866 

Under Executive Order 12866 (58 FR 

51736 (Oc+ober 4,1993)), the Agency 

must deteimine whether the regulatory 

action is "significant" and therefore 

subject to Office of Management and 

Budget (OMB) review and the 

requirements of the Executive Order. 

The Order defines "significant 

regulatory action" as one that is likely 

to result in a rule that may: 

(1) Have an annual effect on the 

economy of $100 milUon or more or 

adversely affect in a material way the 

economy, a sector ofthe economy, 

productivity, competition, jobs, the 

environment, pubUc health or safety, or 

State, local, or tribal governments or 

communities, 

(2) Create a serious inconsistency or 

otherwise interfere with an action taken 

or planned by another agency, 

(3) Materially alter the budgetary 

impact of entitlements, grants, user fees, 

or loan programs or the rights and 

obligations of recipients thereof; or 

(4) Raise novel legal or policy issues 

arising out of legal mandates, the 

President's priorities, or the principles 

set forth in the Executive Order. 

Pursuant to the terms of Executive 

Order 12866, OMB has notified EPA 

that this action is a "significant 

regulatory: action" within the meaning 

ofthe Executive Order. For this reason, 

this action was submitted to OMB for 

review. Changes made in response to 

OMB suggestions or recommendations 

will be documented in the public 

record. 

D. Paperwork Reduction Act 

' The information collection 

requirements in this proposed rule have 

been submitted for approval to OMB 

under the Paperwork Reduction Act, 44 

U.S.C. 3501 et seq, An Information 

Collection Request document has been 

prepared by EPA (ICR No. 1611) and a 

copy may be obtained from Sandy 

Fanner, Information Policy Branch, U. 

S. Environmental Protection Agency, 

401 M Street SW., (2136), Washington, 

DC 20460 or by calling (202) 260-2740. 

The pubUc repo:rting burden for this 

collection of information is estimated to 

average 103 hours per source for 

reporting annually over the first 3 years 

and 253 hours per source for 

recordkeeping annually. This includes 

time for reviewing instructions, 

searching existing data sources, 

gathering and maintaining the data 

needed, and completing and reviewing 

the collection of information. 

Send comments regarding the burden 

estimate or any other aspect of this 

collection of information, including 

suggestions for reducing this burden, to 

Chief, Information PoUcy Branch, 2136, 

U. S. Environmental Protection Agency, 

401M Street SW., Washington, DC 

20460; and to the Office of Information 

and Regulatory Affairs, Office of 

Management and Budget, Washington, 

DC 20503, marked "Attention: Desk 

Officer for EPA." The final rule will 

respond to any OMB or pubUc 

comments on the information collection 

requirements contained in this proposal. 

E. Regulatory Flexibility Act 

The Regulatory FlexibiUty Act (5 

U.S.C. 601 et seq.) requires EPA to 

consider potential impacts of proposed 

regulations on small business "entities." 

If a preliminary analysis indicates that 

a proposed regulation would have a 

significant economic impact on 20 

percent or more of small entities, then 

a regulatory flexibility analysis must be 

prepared. 

The EPA's 1982 Regulatory Flexibility 

Act guidelines indicate that an 

economic impact should be considered 

significant if it meets one ofthe 

following criteria: 

(1) Annual compUance costs increase 

the total cost of production for small 

entities by more than 5 percent; 

(2) CompUance costs as a percentage 

of sales for small entities are at least 10 

percent more than compUance costs as 

a percentage of sales for large entities; 

(3) Capital costs of compUance 

represent a significant portion of capital 

available to small entities, considering 

internal cash flow plus external 

financial capabilities; and 

(4) The requirements of the regulation 

are hkely to result in closures of small 

entities. 

Using the SmaU Business 

Administration's definition of a small 

business for SIC Code 3471 of less than 

500 employees, it has been determined 

that none of the above criteriaare 

triggered. In the hard electroplating 

source category the number of small 

businesses is estimated to be 1,170. 

None ofthe regulatory alternatives 

considered will significantly impact 20 

percent of this population. For eTxampIe, 

the estimated number of small entity 

closures ranges from less than 2 percent 

for RA I to less than 5 percent for RA 

IV. As for decorative electroplating and 

anodizing tanks, the low annualized 

compliance costs associated with the 

RA's would not cause any of the criteria 

for a significant impact to be triggered. 

Pursuant to the provisions of 5 U.S.C. 

605(b), I hereby certify that this 

proposed rule, if promulgated, will not 

have a significant economic impact on 

a substantial number of small business 

entities. 

F. Miscellaneous 

In accordance with section 117 ofthe 

Act, publication of this proposal was 

preceded by consultation with 

appropriate advisory committees, 

independent experts, and Federal 

departments and agencies. The 

Administrator wiU welcome comments 

on all aspects of the proposed 

regulation, including economic and 

technological issues, and on the 

proposed test methods. 

This regulation wiU be reviewed 8 

years from the date of promulgation. 

This review wiU include an assessment 

of such factors as evaluation ofthe 

residual health risks, any overlap with 

other programs, the existence of 

alternative methods, enforceabihty, 

improvements in emission control 

technology and health data, and 

reporting and recordkeeping 

requirements. 

List of Subjects in 40 CFR Part 63 

Environmental protection, Air 

pollution control, Hazardous 

substances, Reporting and 

recordkeeping requirements, 

Dated: November 30,1993 

Carol M. Browner, 

Administrator. 

It is proposed that part 63, chapter I, 

title 40 of the Code of Federal 

Regulations be amended as follows: 

PART 63—[AMENDED] 

1. The authority citation for part 63 

continues to read as follows: 

Authority: 42 U.S.C- 7401 et seq. 

2. By adding a new subpart N, 

consisting of §§63.340-63.347, fo read 

as follows: 
P.34 

Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 65799 

Subpart N—National Emission Standards 

for Chromium Emissions From Hard and 

Decorative Chromium Electroplating and 

Chromium Anodizing Tanks 

Sec. -. 

63.340 Applicability and designation of . 

sources. 

63.341 Definitions. 

63.342 Standards. 

63.343 Compliance and performance 

testing. 

63.344 Test methods and procedures. 

63.345 Monitoring requirements. 

63.346 Recordkeeping requirements. 

63.347 Reporting requirements. 

Subpart N—National Emission 

Standards for Chromium Emissions 

From Hard and Decorative Chromium 

Electroplating and Chromium 

Anodizing Tanks 

§ 63.340 Applicability and designation of 

sources. 

The affected source to which the 

provisions of this subpart apply is each 

electroplating or anodizing tank at 

faciUties performing hard chromium 

electroplating, decorative chromium 

electroplating, or chromium anodizing. 

§63.341 Definitions. 

Terms used in this subpart are 

defined in the Clean Air Act, in subpart 

A of part 63, or in this section as 

follows:i 

Affected source means the chromium 

electroplating or anodizing tank. 

Air pollution control device means 

equipment used to collect and contain 

chromium emissions from chromium 

electroplating and anodizing tanks. 

Anodizing means the surface 

treatment of metals, particularly 

aluminum, where the part to be 

anodized serves as the anode and an 

oxide film is produced on the surface of 

the base metal. 

Base metal means the metal or metal 

alloy the workpiece is composed of. 

Chemical fume suppressant means 

any chemical agent that reduces or 

suppresses fumes at the surface of an 

electroplating or anodizing bath. 

Chromic acid means the common 

name for chromium anhydride (CrOs). 

Chromium anodizing means the 

process by which an oxide layer is 

produced on the surface of a base metal 

using a chromic acid solution. 

Chromium electroplating means the 

process by which a layer of chromium 

metal is electrodeposited on a base 

metal or plastic. 

Composite mesh-pad system means 

an air pollution control device typically 

consisting of several stages. The purpose 

i The EPA proposed regulations for subpart A of 

40 CFR part 63 published in the Federal Register 

on August 11,1993 at 58 FR 42760. 

of the first stage is to remove large 

particles. Smaller particles are removed 

in the second stage, which consists of 

the composite mesh-pad. A final stage 

may remove any reentrained particles 

not collected by the composite meshpad. 

Decorative chromium electroplating 

means the process by which a thin layer 

of chromium is electrodeposited on a 

base metal or plastic to provide a bright 

surface with wear and tarnish 

resistance. 

Electroplating means the 

electrodeposition of an adherent 

metalUc coating upon an electrode 

(workpiece) to secure a surface with 

properties different from those of the 

base metal. 

Electroplating or anodizing bath 

means the electrolytic solution used as 

the conducting medium in which the 

flow of current is accompanied by 

movement of metal ions for the 

purposes of electroplating metal out of 

the solution onto a base metal or plastic 

or for oxidizing the base metal. 

Electroplating or anodizing tank 

means the receptacle or container in 

which electroplating or anodizing 

occurs. 

Facility means all contiguous or 

adjoining property that is under 

common ownership or control, 

including properties that are separated 

only by a road or other pubUc right-ofway, in which hard chromium 

electroplating or chromium anodizing is 

performed. 

Foam blanket means the type of 

chemical fume suppressant that 

generates a layer of foam across the 

surface of a solution when current is 

applied to that solution. 

Gas velocity means the velocity of the 

inlet gas stream to the air pollution 

control device. 

Hard chromium electroplating means 

a process by which a thick layer of 

chromium is electrodeposited on a base 

metal to provide a surface with wear 

resistance, a low coefficient of friction, 

hardness, and corrosion resistance. 

Hexavalent chromium means the form 

of chromium in a valence state of -1-6. 

Large hard chromium electroplating 

facility means a facility that performs 

hard chromium electroplating and has a 

maximum cumulative potential rectifier 

capacity greater than or equal to 60 

milUon ampere-hours per year (Ah/yr). 

Maximum cumulative potential 

rectifier capacity means the summation 

of the total installed rectifier capacity at 

a facility, expressed in amperes, 

multipUed by an operating schedule of 

8,400 hours per year and 0.7, which 

assumes that electrodes are energized 70 

percent ofthe total operating time. 

Operating parameter value means a 

minimum or maximum value 

established for a control device or 

process parameter which, if achieved by 

itself or in combination with one or 

more other operating parameter values, 

determines that an owner or operator 

has complied with an applicable 

emission limitation or standard. 

Packed-bed scrubber means an air 

poUution control device consisting of a 

single or double packed-bed that 

contains packing media on which the 

chromic acid droplets impinge. The 

packed-bed section of the scrubber is 

followed by a mist eliminator to remove 

any water entrained from the packedbed section. 

Small hard chromium electroplating 

facility means a facility that performs 

hard chromium electroplating and has a 

maximum cumulative potential rectifier 

capacity less than 60 million Ah/yr. 

Stalagmometer means the device used 

to measure the surface tension of a 

solution. A tensiometer may also be 

used. 

Surface active agent means any 

soluble or colloidal substance that, even 

when present in very low 

concentrations, affects markedly the 

surface tension of solutions. 

Surface tension means the property, 

due to molecular forces, that exists in 

the surface film of all liquids and tends 

to prevent liquid from spreading. 

Trivalent chromium means the form 

of chromium in a valence state of+3. 

Trivalent chromium process means 

the process used for electrodeposition of 

a thin layer of chromium onto a base 

metal using a trivalent chromium 

solution instead of a chromic acid 

solution. 

Wetting agent means any substance 

that reduces the surface tension of a 

liquid. 

Workload means the amount of 

material or parts processed in the 

electroplating or anodizing tank at a 

given time. 

Workpiece means the material being 

plated, anodized, or otherwise finished. 

§63.342 Standards. 

(a) Standards for hard chromium 

electroplating tanks. On and after the 

date on which the initial performance 

test is completed or is required to be 

completed under § 63.7, whichever date 

is earlier, no owner or operator of an 

existing or new affected source shall 

cause to be discharged into the 

atmosphere from that affected source 

any gases that contain chromium 

emissions in excess of: 

(1) 0.013 milligrams of total 

chromium per dry standard cubic meter 

(mg/dscm) of ventilation air (5.7xl0_« 
65800 Federal Register / VoL 58, No. 240 / Thursday, December 16, 1993 / Proposed Rulegrains per dry standard cubic foot [gr/ 

dscf]); or 

(2) 0.03 mg/dscm (1,3x10-* gr/dsefl if 

the electroplating tank is an existing 

source and is located at a small hard 

chromium electroplating faciUty. 

(b) Standards for decorative 

chromium electroplating tanks using a 

chromic acid bath. On and after the 

compUance date identified in § 63.343, 

no owner or operator of an existing or 

new affected source shall aUow: 

(1) The concentration of chromium in 

the exhaust gas stream discharged to the 

atmosphere to exceed 0.003 mg/dscm 

(1.3x10-6 gr/dscf) if an air poUution 

control device is the sole means of 

reducing emissions; or 

(2) Tha surface tension of the 

electroplating bath to exceed 40 dynes 

per centimeter (dynes/cm) (2.7x10-' 

] ound-force per foot (lbf/ft)) at any time 

curing operation of the tank if fume 

suppressants are used in the plating 

bath. 

(c) Standard for decorative chromium 

electroplating tanks using a trivalent 

chromium bath. On and after the 

compUance date identified in § 63.343, 

no owner or operator of an existing or 

new affected source shall allow: 

(1) The concentration of chromium in 

the exhaust gas stream discharged to the 

atmosphere to exceed 0.048 mg/dscm 

(2.71x10 -- gr/dscf) if an air poUution 

control device is the sole means of 

reducing emissions; or 

(2) The surface tension of the 

electroplating bath to exceed 55 dynes/ 

cm (3.8x10-3 lbf/ft) at any time during 

operation of the tank if fume 

Suppressants are used in the plating 

bath. 

(d) Standards for chromium 

anodizing tanks. On and after the 

compUance date identified in §63.343, 

no owner or operator of an existing or 

new affected source shall aUow: 

(1) The concentration of chromium in 

the exhaust gas stream-discharged to the 

atmosphere to exceed 0.003 mg/dscm 

(1.3xl0-6 gr/dscf) if an air pollution 

control device is the sole means of 

reducing emissions; or 

(2) The surface tension ofthe 

chromium anodizing bath to exceed 40 

dynes/cm (2.7x10-* lbf/ft) at any time 

during operation of the tank if fume 

suppressants are used in the plating 

bath. 

(e) Operation and maintenance plan. 

The owner or operator of an affected 

source that uses an air poUution control 

device to control emissions of 

chromium trom the electroplating or 

anodizing tank shall prepare a startup, 

shutdown, malfunction plan in 

accordance with § 63.6 of subpart A. 

The plan shall be implemented within 

90 days after the effective date of this 

subpart and shall also include the 

following provisions: 

• (1) The plan shall specify the 

operation and maintenance criteria for 

the air pollution control device and 

shall include a standardized checklist to 

document the operation and 

maintenance of tha equipment; 

(2) The plan shall include a 

systematic procedure for identifying 

malfunctions and for reporting them 

immediately to supervisory personnel; 

and 

(3) The plan shall specify procedures 

to be followed to ensure that equipment 

or process malfunctions due to poor 

maintenance or other preventable 

conditions do not occur. 

(f) The provisions of paragraph (e) of 

this section do not apply to an owner or 

operator who complies with these 

standards by meeting the surface 

tension limits in paragraphs'(b)(2), 

(c}(2), and (d)(2) of this section. 

§ 63.343 Compliance and performance 

testing. 

(a) Compliance dates. (1) Hard 

chromium electroplating tanks. An 

owner or operator of an existing source 

shall comply with the standard- within 

1 year after the effective date of the 

standards. An owner or operator of a 

new source shall comply with the 

standards immediately upon startup. 

(2) Decorative chromium 

electroplating tanks. An owner or 

operator of an existing source shall 

comply with the standards within 3 

months after the effective date ofthe 

standards. An owner or operator of a 

new source shall comply with the 

standards immediately upon startup. 

(3) Chromium anodizing tanks. An 

owner or operator of an existing source 

shall comply with the standards within 

3 months after the effective date of the 

standards. An owner or operator of a 

new source shall comply with the 

standards immediately upon startup. 

(b) The following procedures shall be 

used to determine compUance with the 

emission limits under § 63.342 (a), 

(b)(1). (c)(1). and (d)(1): 

(1) The owner or operator shall 

conduct an initial performance test as 

required under § 63.7 using the 

procedures and test methods Usted in 

§§ 63.7 and 63.344. During tins 

performance test, the owner or operator 

shall determine tha outlet chromium 

concentration as well as the following: 

(i) For sources complying with 

§ 63.342(a) through the use of a 

composite mesh-pad system or a 

packed-bed scrubber system, the owner 

or operator shall establish as a sitespecific operating parameter the 

acceptable gas velocity value or range of 

gas velocity values using the procedures 

in §63.344. 

(ii) For sources complying with 

§ 63.342(a) through the use of a packedbed scrubber system* tha owner or 

operator shall estabUsh as a site-specific 

operating parameter the concentration 

of chromium in the scrubber water 

using a hydrometer and following 

manufacturer's instructions. 

(iii) As an alternative to the 

requirement in paragraph (b)(1)(h) of 

this section, the owner or operator may 

accept 45 grams per liter (g/L) (6 ounces 

per gallon (oz/gal)) as the value of the. 

site-specific operating parameter for the 

concentration of chromium in the 

scrubber water. 

(2) On and after the date on which the 

initial performance test is completed or 

is required to be completed under 

§63.7, the owner or operator of an 

affected source shall: 

(i) For sources complying with 

§63.342 (a), (b)(1). (cKD. or (d)(1) 

through the use of a composite meshpad or packed-bed scrubber system, 

monitor the gas velocity in accordance 

with the requirements in §63.345. 

Operation ofthe affected source at a gas 

velocity outside of the range of gas 

velocity estabUshed during the initial 

performance test shall constitute 

noncompUance with the standards. 

(ii) For sources complying with 

§ 63.342 (a), (b)(1), (c)(1). or (d)(1) 

through the use of a packed-bed 

scrubber system, monitor the chromium 

concentration in the scrubber water in 

accordance with the requirements in 

§ 63.345. Operation ofthe affected 

source at a scrubber water chromium 

concentration in excess of either 45 g/ 

L (6 oz./gal) or the value estabUshed 

during the initial performance test shaU 

constitute noncompUance with the 

standards. 

(c) The following procedures shall be 

used to determine compUance with the 

surface tension limits under § 63.342 

(b)(2). (c)(2). and (d)(2); 

(1) The owner or operator shall 

measure the surface tension of the 

electroplating or anodizing bath using 

the test methods identified in § 63.344. 

(2) On and after the compUance date 

identified in § 63.343(a), the owner or 

operator of an affected source shall 

monitor the surface tension in 

* accordance with the requirements in 

Method 306B in appendix A to this part. 

Operation of the affected source at a 

surface tension in excess of those 

required by § 63.342 (b)(2), (c)(2), and 

(d)(2) shall constitute noncompUance 

with the standards. 

(3) As an alternative to meeting the 

surface tension limits identified in 
P.36 

Federa l Register / Vol. 58. No. 240 / Thursday, December 16, 1993 / Proposed Rules 6580 1 

§ 63.342 (b)(2). (c)(2). and (d)(2). the 

owner or operator of an affected source 

may: 

(l) Conduct a performance test using 

the procedures and test methods listed 

in § 63.7 and §63.344. During this 

performance test, the owner or operator 

shall determine the outlet chromium 

concentration and shall estabhsh as a 

site-specific operating parameter the 

surface tension of the electroplating or 

anodizing bath that corresponds to 

compliance with the emission limits 

under § 63.342 (b)(1). (c)(1). or (d)(1); 

and 

(ii) On and after the date on which the 

initial performance test is completed or 

is required to be completed under 

§ 63.7, the owner or operator of an 

affected source shall monitor the surface 

tension in accordance with the 

requirements in Method 306B in 

appendix A of this part. Operation of 

the affected source at a surface tension 

in excess ofthe value established during 

the initial performance test shall 

constitute noncompliance with the 

standards. 

(d) An owner or operator who uses an 

air pollution control device not listed in 

§ 63.343 shall submit a description of 

the device, test data verifying the 

performance of the device for reducing 

chromium emissions to the atmosphere, 

a copy ofthe operation and 

maintenance plan referenced in 

§ 63.342(e), and appropriate operating 

parameters that will be monitored to 

establish compliance with tha 

standards, subject to the Administrator's 

approval. 

§ 63.344 Teat mathods and procedural 

(a) Each owner or operator subject to 

the provisions of this subpart 

concerning the use of air pollution 

control devices to control chromium 

emissions shall use the test methods 

identified in this section to demonstrate 

compliance with the standards in 

§63.342. 

(b) Method 306 or Method 306A. 

"Determination of Chromium Emissions 

from Decorative and Hard Chromium 

Electroplating and Anodiring 

Operations" shall be used to determine 

the concentration of total chromium in 

emissions from hard or decorative 

chromium electroplating tanks or 

chromium anodizing tanks. The 

sampling time and sample volume for 

each run of Method 306 shall be at least 

60 minutes and 0.85 dscm (30 dscf). 

respectively. The sampling time and 

sample volume for each run of Method 

306A shall be 120 minutes and 1.70 

dscm (60 dscf). respectively. 

(c) Method 306B. '•Surface Tension 

Measurement and Recordkeeping for 

Tanks used at Decorative Chromium 

Electroplating and Anodizing 

Facilities," shall be used to measure the 

surface tension of electroplating and 

anodizing baths. 

§63.345 Monitoring requirement*. 

(a) During the initial performance test 

required by § 63.7 and § 63.343. the 

owner or operator of a tank that uses an 

air pollution control device shall 

establish the range of the pressure drop 

across the air pollution control device as 

a site-specific operating parameter 

according to the procedures in 

paragraphs (a)(1) through (a)(3) of this 

section. 

(1) Locate a velocity traverse port in 

a section of straight duct that connects 

the hooding on the plating tank with the 

control device. The port shall be located 

as close to the plating tank as possible, 

and shall be placed a minimum of 2 

duct diameters downstream and 0.5 

diameter upstream of any flow 

disturbance such as a bend, expansion, 

or contraction (see Method 1. 40 CFR 

part 60, appendix A). If 2.5 diameters of 

straight duct work does not exist, locate 

the port 0.8 of the duct diameter 

downstream and 0.2 ofthe duct 

diameter upstream from any flow 

disturbance. If the control device serves 

multiple tanks, locate a port on the 

straight duct work ofeach tank. 

(2) A 12-point velocity traverse of the 

duct leading from each tank shall be 

conducted along a single axis according 

to Method 2 (40 CFR part 60. appendix 

A) using an S-type pitot tube; 

measurement of the barometric pressure 

and duct temperature at each traverse 

point is not required, but is suggested. 

Mark the S-type pitot tube as specified 

in Method 1(40 CFR part 60. appendix 

A) with 12 points. Measure the Ap 

values for the velocity points and 

record. Stack temperature should be 70° 

F plus or minus 5° F at the time that the 

measurements are made. Determine the 

square root values ofthe individual 

velocity points and average. The poi 

with the square root value that comes 

closest to the average square root value 

is the point of average velocity. The 

range of Ap values measured for this 

point during the performance test will 

be used as the reference for future 

monitoring. 

(3) If one control device serves several 

plating tanks, a reference range for the 

Ap must be established during the 

performance test for the duct work from 

each tank. If flow through the ducts of 

one or more tanks is shut off during 

certain process operations, a separate 

reference range for the Ap must be 

estabUshed for those ducts that are left 

operating. Reference Ap values must be 

established during die performance test 

for all combinations of tank operation 

and duct flows that can occur. 

(b) The owner or operator of a tank 

with a conventional packed-bed 

scrubber shall adhere to, at a minimum, 

the following maintenance practices in 

accordance with the operation and 

maintenance plan required by 

§ 63.342(e): 

(1) At least once each mos illy 

inspect the device to ensure there is 

proper drainage, no chromic: 

buildup on the packed bed. anti 

evidence of chemical attack on the 

structural integrity ofthe device; 

(2) At least once each day. I 

inspect the back portion of the chavn 

blade mist eliminator t • t is dry 

and there is no breakthrough of < 

acid mist; 

(3) When makeup additions occur, 

ensure that all mak< 

and supplied to the unit at the top oi 

packed bed; 

(4) At least once each di 

the gas velocity prior to the I 

device. The gas velocity shall be 

determined at the point of average 

velocity identified during 11 

performance test in accordance with 

paragraph (a) of this section. 

Periodically determine that 1 

openings of the pitot tube are clear; 

clean chromic acid from the 

pitot, when necessary. 

(5) At least once each day. di 

the concentration of ci 

scrubber water by using a hy<: 

and 

(6) At least once each day, deter; 

the pressure drop across the packed 

bed(s). If the pressure drop exceeds I 

value established in accordance r 

paragraph (a) of this sec 

be documented and operation B 

maintenance procedures are to be 

reviewed. Any corrective action tha' 

taken must also be documented 

(c) The owner or operator of a tank 

with a composite mesh-pad system shall 

adhere to, at a minimum, the following 

maintenance p rail ices in accord 

with the operation and tnai 

plan required by § 63.342(d): 

(1) At least once each month, visually 

inspect the device to ensure there is 

proper drainage, no chromic 

buildup on the packed bed. and no 

evidence of chemical attack on \ 

structural integrity ofthe dt> 

(2) At least once each day, visually 

inspect the back portion ofthe mesh 

pad closest to the fan to ensure there is 

no breakthrough of chromic acid mist; 

(3) When makeup additions on 

ensure that all makeup water is fresh 

and supplied to the unit at the top of the 

packed bed; 
65802 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

(4) At least once each day, shut the 

fan and the plating tank off and wash 

down the composite mesh pads for at 

least 10 minutes; 

(5) At least once each day, determine 

the gas velocity prior to the control 

devices in accordance with the 

requirements of paragraph (b)(4) of this 

section. 

(6) If a packed-bed scrubber is used in 

conjunction with the composite meshpad system, at least once each day, 

determine the concentration of chromic 

acid in the scrubber water by using a 

hydrometer; and 

(7) At least once each day, determine 

the pressure drop across the device. If 

the pressure drop exceeds the value 

established in accordance with 

paragraph (a) of this section, the 

exceedance shall be documented and ' 

the operation and maintenance 

procedures shall be reviewed. Any 

corrective action that is taken must also 

be documented. 

(d) Each owner or operator of a tank 

that uses a wetting agent or a 

combination wetting agent and foam 

blanket shall monitor the bath to 

maintain the surface tension values 

established in § 63.342(b)(2), (c), and 

(d)(2). The surface tension shall be 

measured every 4 hours during 

operation of the tank with a 

stalagmometer or a tensiometer as 

specified in Method 306B, appendix A 

of this part. 

(e) Each owner or operator of a tank 

that uses a foam blanket to comply with 

the requirements of § 63.342(a), (b)(1), or 

(d)(1) shall maintain a foam thickness 

greater than or equal to the level 

established during the performance test 

or 2.54 cm (1 inch) (whichever is 

greater) at all times. The foam thickness 

shall be measured once each hour. 

§63.346 Recordkeeping requirements. 

(a) The owner or operator of each 

electroplating tank that uses an add-on 

air pollution control device to meet the 

emission limit shall maintain records of 

daily and monthly inspections, daily gas 

velocity readings, daily scrubber water 

chromium concentrations (if 

applicable), daily washdowns, daily 

pressure drop readings, and any 

emission tests at the facility for a 

minimum of 5 years. 

(1) Each inspection record shall 

identify the device inspected and 

include the following: The date and 

approximate time of inspection, a brief 

description ofthe working condition of 

the device during the inspection, the gas 

velocity, the scrubber water chromium 

concentration (if applicable), the 

pressure drop, and any actions taken to 

correct deficiencies found during the 

inspection. 

(2) Each record of washdown shall 

identify the device and include the date, 

approximate time, and duration ofthe 

washdown. 

(b) The owner or operator of each 

electroplating tank that uses a chromic 

acid solution and that uses a fume 

suppressant to comply with the 

standard shall maintain the following 

records at the faciUty for at least 5 years: 

(1) The amount of fume suppressants 

purchased (invoices). 

(2) Measurements of the surface ' 

tension ofthe bath. 

(3) The frequency of maintenance 

additions. 

(4) The amount of material added 

during each maintenance addition. 

(5) If foam blankets are used, 

measurements of foam blanket 

thickness. 

(6) Any emission tests to assure 

compliance with the standard. 

(c) Each record of a foam blanket 

thickness measurement shall identify 

the electroplating tank and include the 

date, approximate time, measured 

thickness, and whether any additions 

were made to the bath. If an addition 

was made, the amount of material added 

would also be recorded. 

(d) Each record of a surface tension 

measurement shall identify the 

electroplating tank and include the date, 

approximate time, measured surface 

tension, and whether any additions 

were made to the bath. 

(e) The owner or operator of each 

electroplating tank that uses a trivalent 

chromium solution shall maintain the 

following records at the facility for at 

least 5 years: 

(1) Measurements ofthe surface 

tension ofthe bath; 

(2) The amount of bath additive 

containing wetting agents purchased 

(invoices); and 

(3) Any emission tests to assure 

compliance with the standard. 

(f) The owner or operator of each 

electroplating tank that uses a chromic 

acid solution and that operates an air 

pollution control device is not required 

to maintain the records required by 

paragraph (a) of this section if the owner 

or operator is complying with 

§ 63.342(b)(2), (c)(2), or (d)(2). If the 

owner or operator is complying with 

§ 63.342(b)(2), (c)(2), or (d)(2). the 

recordkeeping requirements of 

paragraphs (b), (c), and (d) of this 

section apply. 

§63.347 Reporting requirements. 

(a) The owner or operator of each 

affected source subject to these 

standards shall fulfill all reporting 

requirements outlined in the General 

Provisions to 40 CFR part 63, subpart A, 

§§ 63.7 through 63.10. These reports 

shall be made to the Administrator or 

delegated State authority. 

(b) The owner or operator ofeach 

existing hard chromium electroplating 

tank shall include the maximum 

cumulative potential rectifier capacity 

of the faciUty in which the tank is 

located in the initial notification report 

required by § 63.9(h). 

(c) The owner or operator of each 

affected source subject to these 

standards shall include the monitored 

operating parameter value reading 

required by § 63.343 in the quarterly 

excess emissions and continuous 

monitoring system performance report 

and summary report required by 

§ 63.10(e). In the case of exceedances, 

the report must also contain a 

description and timing of the steps 

taken to address the cause ofthe 

exceedance. 

3. By adding methods 306, 306A, and 

306B in numerical order to read as 

follows. 

Appendix A to Part 63—Test Methods 

Method 306—Determination of Chromium 

Emissions From Decorative and Hard 

Chromium Electroplating and Anodizing 

Operations 

1. Applicability and Principle 

1.1 Applicability. This method applies to 

the determination of chromium (Cr) in 

emissions from decorative and hard chrome 

electroplating facilities and anodizing 

operations. 

1.2 Principle. Emissions are collected 

from the source by using a Method 5 

sampling train (40 CFR part 60, Appendix A), 

with the filter omitted and a glass nozzle and 

probe liner. The chromium emissions are 

collected in an alkaline solution: 0.1 N 

sodium hydroxide (NaOH) or 0.1 N sodium 

bicarbonate (NaHCOa). The collected samples 

remain in the alkaline solution until analysis. 

The chromium sample is analyzed using 

inductively coupled plasma emission 

spectrometry (ICP) at 267.72 nm. 

Alternatively, if improved detection limits 

are required, a portion of the alkaline 

impinger solution is digested with nitric acid 

and analyzed by graphite furnace atomic 

absorption spectroscopy (GFAAS) at 357.9 

nm. 

2. Range, Sensitivity, Precision, and 

Interferences 

2.1 Range. A linear response curve for 

ICP can be obtained in the range 10 ng Cr/ 

liter to at least 500 |_g Cr/liter. A linear 

response curve for GFAAS can be obtained 

in the range 5 ng Cr/liter to 150 ng Cr/liter. 

The upper limit of both techniques can be 

extended by appropriate dilution. 

2.2 Sensitivity. Minimum detection limits 

of 7 ng Cr/liter for ICP and 1 ng Cr/liter for 

GFAAS have been observed. 
P.38 

Ksgister / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

2.3 Precision. To be determined. 

2.4 GFAAS Inter&renoBS. Low 

concentrations of calcium and/or phosphate 

may cause interferences; at concentrations 

above 200 ng/L, calcium'o effect is constant 

and eliminates the effect of phosphate. 

Calcium nitrate io therefore added to ensure 

a known conatant effect Other matrix 

modifiers recommended by __> instrument 

manufacturer may also be suitable. Nitrogen 

should not bs used as ths purge gas due to 

cyanide band interference. Background 

correction may be required because of 

possible significant levels of nonspecific 

absorption and scattering at fhe 357.9 nm 

analytical wavelength. Zeeman or SmitiiHieftj- background correction is 

recommended to correct for interferences due 

to high levels of dissolved solids in the 

alkaline impinger solutions. 

2.5 Ity Interferences. 

2.5.1 Spectral Interferences. Spectral 

interferences are caused by: (1) Overlap of a 

spectral line from another element; (2j 

unresolved overlap of molecular band 

spectra; (3) background contribution from 

continuous cr recombination phenomena; 

and (4) stray light from the line emission of 

high-concentration elements. Spectral 

overlap may be compensated for by computer 

correcting lie raw data after monitoring and 

measuring the interfering element. At-the 

267.72 nm Cr analytical wavelength, iron, 

manganese and uranium are potential 

interfering elements. Background and stray 

light interferences can usually be 

compensated for by a background correction 

adjacent to the analytical line. Unresolved 

overlap requires the selection of an 

alternative chromium wavelength. Consult 

the instrument manufacturer's operation 

manual for interference correction 

procedures. 

2.5.2 Physical Interferences. High levels 

of dissolved solids in the samples may cause 

significant inaccuracies due to salt buildup at 

the nebulizer and torch tips. This problem 

can be controlled by diluting the sample or 

providing for extended rinse times between 

sample analyses. Standards are prepared in 

the same matrix as the samples (i.e., 0.1 N 

NaOH). 

2.5.3 Chemical Interferences. These 

include molecular compound formation, 

ionization effects and solute vaporization 

effects, and are usually not significant in ICP, 

especially if the standards and samples are 

matrix matched. 

3. Apparatus 

3.1 Sampling Train. Same as Method 5, 

Section 2.1, but omit filter, and use quartz or 

glass for probe and liner in place of stainless 

steel. Use 0.1 N NaOH or 0.1 N NaHC03 in 

the impingers in place of water. 

3.2 Sample Recovery. Same as Method 5, 

Section 2.2, but use 0.1 NNaOH or 0.1 N 

NaHCOj in place of acetone. Rinse probe 

nozzle, probe liner, impingers and 

connecting glassware into a single sample 

container. 

3.3 Analysis. For analysis, the following 

equipment is needed. 

3.3.1 General 

3.3.1.1 Phillips Beakers. 

3.3.1.2 HotPlate. 

3.3.1.3 Volumetric Flasks. Class A100 ml 

and other appropriate volumes. 

3.3.1A Assorted Pipettes. 

3.3.2 Analysis by GFAAS. 

3.3.2.1 Chromium Hollow Cathode Lamp 

or Electrodeless Discharge Lamp. 

3.3.2.2 Graphite Furncce Atomic 

Absorption Spectrophotometer. 

3.3.3 Analysis by ICP. > 

3.3.3.1 ICP Spectrometer. Computercontrolled emission spectrometer with 

background correction and radio frequency 

generator. 

3.3.3.2 Argon Gas Supply. Welding grade 

or better. 

4. Reagents 

Unless otherwise indicated, all reagents 

shall conform to the specifications 

established by the Ccmmittee on Analytical 

Reagents ofthe American Chemical Society 

(ACS reagent grade). Where such 

specifications are not available, use the best 

available grade. 

4.1 Sampling. 

4.1.1 Water. Deionized, distilled, that 

conforms to ASTM Type D water for analysis. 

4.1.2 Sodium Hydroxide (NaOH) 

Absorbing Reagent, 0.1 N or Sodium 

Bicarbonate (NaHCOs) Absorbing Reagent, 

0.1 N. Dissolve 4.0 gm of sodium hydroxide 

in 1 L of water, or dissolve 8.5 gm of sodium 

bicarbonate in 1L of water. 

4.2 Sample Recovery. 

4.2.1 0.1 N NaOH or 0.1 N NaHCOj. See 

Section 4.1.2. Use the same reagent for 

recovery that was used in die impingers. 

4.3 Sample Preparation and Analysis. 

4.3.1 Concentrated Nitric Acid (HNOj). 

Trace metals or better grade HNO3 must be 

used for reagent preparation; ACS reagent 

grade HNO3 is acceptable for cleaning 

glassware. 

4.3.2 Matrix Modifier. See instrument 

manufacturer's manual for suggested matrix 

modifier. 

4.3.3 Total Chromium Standard Stock 

Solution (1OC0 mg/L). Procure a certified 

aqueous standard or dissolve 2.829 g of 

potassium dichromate (KjCrjO?) in water and 

dilute to 1 L. 

4.3.4 Total Chromium Standards for 

GFAAS. Chromium solutions for GFAAS 

calibration shall be prepared to contain 1.0% 

(v/v) HNO3. The aero standard shall be 1.0% 

(v/v) HNO3. 

4.3.5 Calibration Standards. Prepare by 

diluting the chromium stock solution (6.2.5) 

in 0.1 N NaOH at the following suggested 

levels: 2 ml of the stock solution in 1000 ml, 

250 ml, and 50 ml to provide 2, 8 and 40 ng 

Cr*B/ml, respectively. 

4.3.6 Calcium Nitrate CafNOjh Solution 

(10 ng Ca/ml). Prepare the solution by 

weighing 36 mg of CatNOah into 0 1-liter 

volumetric flask. Dilute widi water to 1 liter. 

5. Procedure 

5.1 Sampling. Same as Method 5, Section 

4.1, except omit the filter and filter holder 

from die sampling train. Use glass nozzle and 

probe liner. Clean all glassware in hot soapy 

water designed for laboratory cleaning of 

glassware. Follow the cleaning with a 

deionized water rinse. Place 100 ml of 0.1 N 

NaOH or 0.1 NaHCOj in each of the first two 

impingers. 

5.2 Sample Recovery. Follow tho basic 

procedures of Method 5, Ssction 4.2. with the 

exceptions noted below; a filter is not 

recovered from this train. 

5.2.1 Container Na 1. Measure the 

volume of tha liquid in __> first, second, and 

third impingers and quantitatively transfer 

into a labelled sample container. Use 200 ml 

of 0.1 N NaOH ox 0.1 N NaHCOj to rinse tho 

nozzle, proba liner, threa impiagara, and 

connecting glassware; add this wash to die 

same container. 

5.2.2 Container No. 2 (Reagent Blank). 

Place 400 ml of 0.1 N NaOH or 0.1 N NaHCOj 

in a labeled sample container. 

5.2.3 Sample Preservation. Refrigerate 

samples upon receipt (Containers Nos. 1 and 

2). 

5.3 Sample Preparation and Analysis. For 

GFAAS measurement, an acid digastion of 

the alkaline impinger solution is required. 

Two types of blanks are required for tho 

analysis. The calibration blank is used in 

establishing the analytical curve, and the 

reagent blank is used to correct for possible 

contamination resulting from tha sample 

processing. The 0.1 N NaOH solution or tho 

O.S N NaKCQ3 from 4.1.2 is used as tho 

calibration blank The reag3nt blank must 

contain all the reagents and be in tho sama 

volume as used in the processing of tho 

samples. The reagent blank must ba carried 

through the complete procedure ond contain 

the same acid concentration in the final 

solution as the sampla solutions analyzed. 

5.3.1 Acid Digastion for GFAAS. In a 

beaker, add 10 ml of concentrated nitric add 

to the sample aliquot of 300 ml taken for 

analysis. Cover the beaker with 0 watch glass. 

Place the beaker'on a hot plate and reflux the 

sample down to near dryness. Add another 

5 ml of concentrated HNOj to complete the 

digestion. Carefully reflux the sample volume 

down to near dryness. Wash down tha beaker 

walls and watch glass with distilled water. 

Adjust the final volume to 50 ml or a 

predetermined volume based on the expected 

Cr concentration. The final concentration of 

HNOj in the solution should be 1% (v/v). 

Transfer the digested sample to a 50 ml 

volumetric flask. Add 0.5 ml of concentrated 

HNOj, 1 ml ofthe 10 ng/ml of Ca(N03hDilute to 50 ml with water. 

5.3.2 Sample.Analysis by GFAAS. The 

357.9-nm wavelength line shall be used. 

Follow the manufacturer's operating 

instructions for all other spectrophotometer 

parameters. 

5.3.2.1 Furnace parameters suggested by 

the manufacturer should be employed as 

guidelines. Since temperature-sensing 

mechanisms and temperature controllers can 

vary between instruments and/or with time, 

the validity of the furnace parameters must 

be periodically confirmed by systematically 

altering the furnace parameters while 

analyzing a standard. In this manner, losses 

of analyte due to higher-than-necessary 

temperature settings or losses in sensitivity 

due to less than optimum settings can be 

minimized. Similar verification of furnace 

parameters may ba required for complex 

sample matrices. 

5.3.2.2 Inject a measured aliquot of 

digested sample into the furnace ond 

atomize. If the concentration found exceeds 
65804 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

the calibration range, die sample should be 

diluted with the same acid matrix and 

reanalyzed. Consult fhe operator's manual for 

-suggested injection volumes. The use of 

multiple injections can improve accuracy 

and help detect furnace pipetting errors. 

5.3.2.3 Subtract a sample blank reading 

from a sample reading to obtain a net 

reading. (Note that the sample blank is the 

"reagent blank.") Employ a minimum of one 

matrix-matched sample blank per sample 

batch to determine if contamination or any 

memory effects are occurring. 

5.3.2.4 Calculate the chromium 

concentrations (1) by the method of standard 

additions (see operator's manual) or (2) from 

die calibration curve, or (3) directly from the 

instrument's concentration readout. All 

dilution or concentration factors must be 

taken into account. 

5.3.2.5 Dilute samples with reagent blank 

solution if they are more concentrated than 

die highest standard. Note that the equation 

in section 8.1 contains a dilution factor to 

account for any dilution. 

5.3.3 Sample Analysis by ICP. The ICP 

measurement is performed directiy on the 

alkaline impinger reagent; acid digestion is 

not necessary provided the samples and 

standards are matrix matched. However, ICP 

may only be used when the solution 

analyzed has a Cr concentration greater than 

50 ng/1 (0.05 ng/ml). 

5.3.3.1 Set up the instrument with proper 

operating parameters including wavelength, 

background correction settings (if necessary), 

interfering element correction settings (if 

necessary). The instrument must be allowed 

to become thermally stable before beginning 

performance of measurements (usually 

requiring at least 30 min of operation prior 

to calibration). During this wannup period, 

the optical calibration and torch position 

optimization may be performed (consult the 

operator's manual). 

5.3.3.2, Before beginning the sample run, 

analyze the highest calibration standard as if 

it were a sample. Concentration values 

obtained should not deviate from the actual 

values by more than 5% (or the established 

control limits, whichever is lower). If they 

do, follow the recommendations ofthe 

instrument manufacturer to correct for this 

condition. 

5.3.3.3 Flush the system with the 

calibration blank solution for at least 1 min 

before the analysis of each sample. Analyze 

the calibration standard blank after each 10 

samples. Use the average intensity of 

multiple exposures for both standardization 

and sample analysis tp reduce random error. 

5.3.3.4 Dilute and reanalyze samples that 

are more concentrated than tiie linear 

calibration limit or use an alternate, less 

sensitive Cr wavelength for which quality 

control data are already established. 

5.3.3.5 If dilutions were performed, the 

appropriate factors must be applied to 

sample values. All results should be reported 

in ng/ml with up to three significant figures. 

6. Calibration 

6.1 Sampling Train Calibration. Perioral 

all of the calibrations described in Method 5, 

Section 5. 

6.2 GFAAS Calibration. Either: (1) Run a 

series of chromium standards and a 

calibration blank and construct a calibration 

curve by plotting the concentrations of tiie 

standards against the absorbencies; or (2) 

using the method of standard additions, plot 

added concentration versus absorbance. For 

instruments that read directiy in 

concentration, set the curve corrector to read 

out the proper concentration, if applicable. 

This is customarily performed automatically 

with most instrument computer based data 

systems. Calibration standards for total 

chromium should start with 1% v/v HNOj 

with no chromium for the zero standard and 

appropriate increases in total chromium 

concentration in other calibration standards. 

Prepare at least three (3) standards (not 

including the zero). The standards should be 

diluted with 0.1 N NaOH and carried through 

the sample preparation procedure to ensure 

that matrix matching is accomplished and to 

avoid the need for the method of standard 

additions. Calibration standards should be 

prepared fresh daily. 

6.3 ICP Calibration. Calibrate the 

instrument according to the instrument 

manufacturer's recommended procedures, 

using a calibration blank and three (3) 

standards for the initial calibration. Be sure 

that samples and standard calibration 

matrices are matrix matched. Flush the 

system with the calibration blank between 

each standard. (Use the average intensity of 

multiple exposures for both standardization 

and sample analysis to reduce random error.) 

7. Quality Control 

7.1.1 GFAAS Quality Control. Run a 

check standard after approximately every 10 

sample injections. These standards are run, 

in part, to monitor the life and performance 

ofthe graphite tube. Lack of reproducibility 

or a significant change in the signal for the 

check standard indicates that the graphite 

tube should be replaced. 

7.1.2 Duplicate Samples. Run one 

duplicate sample for every 20 samples, (or 

one per source test, whichever is more 

frequent) providing there is enough sample 

for duplicate analysis. Duplicate samples are 

brought through the whole sample 

preparation separately. 

7.1.3 Matrix Spiking. Spiked samples 

shall be prepared and analyzed daily to 

ensure that correct procedures are being 

followed and that all equipment is operating 

properly. Spiked sample recovery analyses 

should indicate a recovery for the Cr spike 

of between 75 and 125%. Spikes are added 

prior to any sample preparation. Cr levels in 

the spiked sample should provide final 

solution concentrations that fall within the 

linear portion of the calibration curve. 

7.1.4 Method of Standard Additions. 

Whenever sample matrix problems are 

suspected and standard/sample matrix 

matching is not possible or whenever a new 

sample matrix is being analyzed, the method 

of standard additions shall be used for the 

analysis of all extracts. Method 12 specifies 

a performance test to determine if the method 

of standard additions is necessary. 

7.1.5 Quality Control Check Sample. The 

concentration of all calibration standards 

should be verified against a quality control 

check sample obtained from an outside 

source. This is done by analyzing the check 

sample immediately following calibration. 

The result should be within 10% of the 

expected value before sample analysis 

begins. 

7.2 ICP Quality Control. 

7.2.1 Interference Check. Prepare an 

interference check solution to contain known 

concentrations of interfering elements that 

will provide an adequate test of the 

correction factors in the event of potential 

spectral interferences. Two potential 

interferences, iron and manganese, may be 

prepared as 1000 ng/ml and 200 ng/ml 

solutions, respectively. The solutions should 

be prepared in dilute HNOj (1-5%). 

Particular care must be taken to ensure that 

the solutions and/or salts used to prepare the 

solutions are of ICP grade purity (i.e., that no 

measurable Cr contamination exists in the 

salts/solutions). Commercially prepared 

interfering element check standards are 

available. Verify the interelement correction 

factors every 3 months by analyzing the 

interference check solution. The correction 

factors are calculated according to the 

instrument manufacturer's directions. If 

interelement correction factors are used 

properly, no false Cr should be detected. 

7.2.2 Quality Control Check Sample. 

Prepare in the same alkaline matrix as the 

calibration standards; it should be at least 

100 times the instrumental detection limit. 

This sample should be prepared from a 

different source/supplier (than the 

calibration standards) and is used to verify 

the accuracy of the calibration curve. Prior to 

sample analysis, analyze one check standard 

prepared from a Cr stock solution source 

other than that used for preparation of the 

calibration curve standards (see 7.2.10). The 

check standard concentration should be at 

least 100 times the minimum detection limit. 

7.2.3 Laboratory Blank. Analyze a 

minimum of one laboratory blank per sample 

batch to determine if contamination or any 

memory effects are occurring. 

7.2.4 Duplicates. Analyze one duplicate 

sample for every 20 samples. A duplicate 

sample is a sample brought through the 

whole sample preparation and analytical 

process. 

8. Emission Calculations 

Carry out the calculations, retaining 

one extra decimal figure beyond that of 

the acquired data. Round off figures 

after final calculations. 

8.1 Total Cr in Sample. Calculate M, the 

total ng Cr in each sample, as follows: 

M = V_,<>C4>F«D Eq. 306-1 

where: 

Vmi = Volume of impinger reagent plus 

rinses, ml. 

C = Concentration of Cr in sample, ng Cr/ml 

(direct instrument readout). 

F - Dilution factor. 

- Volume of aliquot after dilution (ml) 

Volume of aliquot before dilution (ml) 

D = Digestion factor. 

= Volume of sample aliquot after digestion 

(ml) 

Volume of sample aliquot submitted to 

digestion (ml) 

8.2 Average Dry Gas Meter Temperature 

and Average Orifice Pressure Drop. Same as 

Method 5, Section 6.2. 
P.40 

Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 65805 

8.3 Dry Gas Volume, Volume of Water 

Vapor, Moisture Content. Same as Method 5, 

Sections 6.3, 6.4, and 6.5, respectively. 

8.4 Cr Emission Concentration. Calculate 

C, (mg/dscm), the Cr concentration in the 

stack gas, dry basis, corrected to standard 

conditions, as follows: 

C = (10-3mg/ng)[M/Vm,Jld)] Eq. 306-2 . 

8.5 Isokinetic Variation, Acceptable 

Results, Same as Method 5, Sections 6.11 and 

6.12, respectively. 

9. Bibliography 

9.1 Test Methods for Evaluating Solid 

Waste. U.S. Environmental Protection 

Agency. SW-846, 2nd Edition. July 1982. 

9.2 Cox, X.B., R.W. Linton, and F.E. 

Butler. Determination of Chromium 

Speciation in Environmental Particles—A 

Multitechnique Study of Ferrochrome 

Smelter Dust. Accepted for publication in 

Environmental Science and Technology. 

9.3 Same as Bibliography of Method 5, 

Citations 2 to 5 and 7. 

9.4 California Air Resources Board, 

"Determination of Total Chromium and 

Hexavalent Chromium Emissions from 

Stationary Sources." Method 425, September 

12,1990. 

9.5 Test Methods for Evaluating Solid 

Waste. U. S. Environmental Protection 

Agency. SW-846, 3rd Edition. November 

1986. 

Method 306 A—Determination of Chromium 

Emissions From Decorative and Hard 

Chromium Electroplating and Anodizing 

Operations 

1. Applicability and Principle 

1.1 Applicability. This method is used to 

determine the concentration of chromium 

emissions from chromium electroplating and 

anodizing operations that use a chromic acid 

bath. The method is less expensive and less 

complex to conduct than Method 306. 

Correctiy applied, the precision and bias of 

the sample results will be comparable to 

those obtained with the isokinetic Method 

306. This method is applicable under 

ambient moisture, air, and temperature 

conditions. 

1.2 Principle. The chromium emissions 

are removed from the duct at a constant 

sampling rate determined by a critical orifice 

and collected in a probe and impingers. The 

sampling time at the sampling traverse points 

is varied according to the stack gas velocity 

to obtain a proportional sample. The 

concentration is determined by the same 

analytical procedures used in Method 306: 

inductively-coupled plasma emission 

spectrometry (ICP) or graphite furnace atomic 

absorption spectrometry (GFAAS). 

2. Range, Sensitivity, Precision, and 

Interferences 

Same as Method 306, Section 2. 

3. Apparatus 

Note: Mention of trade names or specific 

products does not constitute endorsement by 

the Environmental Protection Agency. 

3.1 Sampling Train. A schematic of the 

sampling train is shown in Figure 306A-1. 

The components of the train are available 

commercially, but some fabrication and 

assembly are required. If Method 306 

equipment is available, the sampling train 

may be assembled as specified in Method 306 

and the sampling rate of the meter box set at 

the delta H@ specified for the calibrated 

orifice; this train is then operated as specified 

in this method. 

3.1.1 Probe Nozzle/Tubing and Sheath. 

Use approximately 'A in. inner diameter (ID) 

glass or rigid plastic tubing about 8 inches 

long with a short 90 degree bend at one end 

to form the nozzle. Grind a slight taper on the 

nozzle end before making the bend. Attach 

the nozzle to flexible tubing of sufficient 

length to collect a sample from the stack. Use 

a straight piece of larger diameter rigid tubing 

(such as metal conduit or plastic water pipe) 

to form a sheath that begins about 1 in. from 

the 90° bend on the nozzle and encases the 

flexible tubing. 

3.1.2 S-Type Pitot. Same as Method 2, 

Section 3. 

3.1.3 Sample Line. Use thick wall flexible 

plastic tubing (polyethylene, polypropylene, 

polyvinylchloride) about Vo in. to VB in. ID 

to connect the train components. A 

combination of rigid plastic tubing and thin 

wall flexible tubing may be used as long as 

neither tubing collapses when leak-checking 

the train. Metal tubing cannot be used. 

BIUJNQ CODE 6560-50-P 
s 

a 

Probe/Nozzle Sheath Assembly 

(1/4" I.D. Tubing) 

250 ml of 

Gas Flow O.IN NaOH 

or 

O.IN NaHCO 

& 

eo 

o 

09 

5? 

! 

2. 

< 

? 

to 

Cb 

a 

CD 

CD 

>-l 

l-» 

05 

ID 

(ai 

yf 

•§ o 

co 

CD 

a. I 

CO 

cn 

Figure 30&-A1 sampling train schematic 

XI 

Tp-
P.42 

Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 65807 

3.1.4 Impingers. One quart capacity 

"Mason" glass canning jars with vacuum seal 

lids are used. Three impingers are required: 

the first is for collecting reagent, the second 

is empty and used to collect any reagent 

carried over from the first impinger, and the 

third contains the drying agent. Install leaktight inlet and outlet tubes for assembly with 

train. The tubes may be made of 

approximately Va in. ID glass or rigid plastic 

tubing. For the inlet tube of the first 

impinger, heat the glass or plastic tubing and 

draw until the tubing separates. Cut the tip 

off until the tip orifice is Viz in. in diameter. 

When fabricating the first impinger, place the 

tip orifice

 3/IB in. above the bottom of the jar 

when assembled. For the second impinger, 

the inlet tube need not be drawn and sized, 

but the tip should be approximately 2 in. 

above the bottom of the jar. The inlet tube of 

the third impinger should extend to about Vi 

in. above the bottom ofthe jar. Locate the 

outlet tube end of all impingers about Vi inch 

beneath the bottom of the lid. 

3.1.5 Manometer. It is inclined, to read 

water column to Vioo in. for the first inch and 

Vio inch thereafter. Range 0-6 in. 

3.1.6 Critical Orifice. The critical orifice 

is a small restriction in the sample line that 

is located upstream of the vacuum pump and 

sets the sample rate at about 0.75 cubic foot 

per minute. An orifice meter can be made of 

Vs in. brass tubing approximately 1 in. long 

sealed inside larger diameter, approximately 

Ve in., brass tubing to serve as a critical 

orifice giving a constant sample flow. 

Materials other than brass can be used to 

construct the critical orifice as long as the 

flow through the sampling train is 

approximately 0.75 cubic foot per minute. 

3.1.7 Connecting Hardware. Standard 

pipe and fittings, V* in. or VB in., are used 

to install vacuum pump and dry gas meter in 

train. 

3.1.8 Pump Oiler. A glass oil reservoir 

with a wick mounted at pump inlet 

lubricates pump vanes. 

3.1.9 Vacuum Pump. "Gast" sliding vane 

mechanical pump with fiber vanes suitable to 

deliver a minimum of 26 in. Hg vacuum and 

2.0 cfm are used. 

3.1.10 Oil Trap. Empty glass oil reservoir 

without wick is mounted at pump outlet to 

prevent oil from reaching the dry gas meter. 

3.1.11 Dry Gas Meter. Residential 175 

cubic feet per hour (CFH) capacity dry gas 

meter with thermometer installed monitors 

meter temperature. 

3.2 Sample Recovery. 

3.2.1 Wash Bottles. These are glass or 

inert plastic, 500 or 1000 ml, with spray tube. 

3.2.3 Sample Containers. The first mason 

jar impinger of the sampling train serves as 

the sample container. A new lid and plastic 

wrap are substituted for the impinger inlet/ 

outlet assembly. 

3.3 Analysis. Same as Method 306, 

Section 3.3. 

4. Reagents 

4.1 Sampling. Same as Section 4.1, 

Method 306. 

4.2 Sample Recovery. Same as Section 

4.2, Method 306. 

5. Procedure 

5.1 Sampling. 

5.1.1. Pretest Preparation. 

5.1.1.1 Port Location. Locate ports as 

specified in Section 2 of Method 1. Use a 

total of 24 sampling points for round ducts 

and 24 or 25 points for rectangular ducts. 

Mark the pitot and sampling probe with thin 

strips of tape to permit velocity and sample 

traversing. For ducts less than 12 inches in 

diameter, use a total of 16 points. 

5.1.1.2 Velocity Traverse. Perform a 

velocity traverse before obtaining samples. 

Figure 306A-2 may be used to record 

velocity traverse data. If testing occurs over 

several days, perform the traverse at the 

beginning of each day. At the end of the test 

effort each day, perform a final traverse. 

Perform traverses as specified in Section 3 of 

Method 2, but record the Ap (velocity head) 

values only. Check the stack temperature 

before and after recording the Ap values and 

use the average of the two temperatures for 

the stack temperature. Enter the Ap values for 

each point. Check for cyclonic flow during 

the first traverse to verify that it does not 

exist; if cyclonic flow does exist, make sure 

that the absolute average angle of 

misalignment does not exceed 20 degrees. If 

the average angle of misalignment exceeds 20 

degrees at an outlet location, install 

straightening vanes to eliminate the cyclonic 

flow. If it is necessary to test an inlet location 

where cyclonic flow exists, it may not be 

possible to install straightening vanes. In this 

case, a variation of the alignment method 

must be used. This must be approved by the 

Administrator. 

BILLING CODE 6560-SO-P 
P.43 

65808 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

PLANT 

DATE ~ TIME 

LOCATION 

OPERATOR(S) 

CIRCLE ONE* 

BEFORE RUN 1 BEFORE RON 2 BEFORE RON 3 

SCHEMATIC 0? PQINTg 

AFTER RON 3 

Traverse 

Point 

Number 

i 

Cyclonic 

Flow 

Angle 

{Degrees) 

, 

A P ••Ap 

, 

v4p x-5 irdn 

AVE 

AVE Numerical 

Minutes 

DecTimal 

Part of 

Minute 

x 60 -

Seconds 

• 

Whole 

Minutes 

+ Seconds -

Sample Time 

AVERAGE AVE 

-

Figure 306A-2. Velocity Traverse and Point Sample Time 

Calculation Sheet 

BILLING CODE 65<?-60-C 
P.44 

Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 65809 

5.1.1.3 Point Sampling Times. Since the 

sampling rate of the train is held constant by 

the critical orifice, it is necessary to calculate 

specific sampling times for each point in 

order to obtain a proportional sample. If all 

sampling can be completed in a single day, 

it is necessary to calculate the point sampling 

times only once. If sampling occurs over 

several days, calculate the point sample 

times for each day using velocity traverse 

data obtained earlier in the day. Determine 

the average ofthe Ap values obtained during 

the velocity traverse (Figure 306A-2). 

Calculate the sampling times for each point 

using Equation 306A-1. Convert ths decimal 

parts of minutes to seconds. If the stack 

diameter is less than 12 inches, use 7.5 

minutes in place of 5 minutes in the equation 

and 16 sampling points. 

Minutes at point = 

Point Ap 

"y Average Ap 

x 5 minutes Eq.306A-l 

Where: 

n=Total sampling points. 

5.1.1.4 Preparation of Sampling Train. 

Assemble the sampling'train as shown in 

Figure 306A-1. Secure the nozzle-liner 

assembly to the sheath to prevent slipping 

when sampling. Before charging, rinse the 

first mason jar impinger with either O.IN 

sodium hydroxide or O.lNi sodium 

bicarbonate; discard the solution. Put 250 ml 

of 0.1 N sodium hydroxide or 0.1N sodium 

bicarbonate sampling solution into the first 

mason jar. Similarly, rinse the second mason 

jar impinger and leave empty. Put silica gel 

into the third mason jar impinger until the 

impinger is half full. Place the impingers into 

an ice bath and check to ensure that the lids 

are tight. 

5.1.1.5 Train Leak Check Procedure. Wait 

until the ice has cooled the impingers before 

sampling. Next, seal the nozzle with a finger 

covered by a piece of clear plastic wrap and 

turn on the pump. Observe any leak rate on 

the dry gas meter. The leak rate should not 

exceed 0.02 cfm. 

5.1.2 Sampling Train Operation. 

5.1.2.1 Record all pertinent process and 

sampling data on the data sheet (see Figure 

306A-3). Ensure that the process operation is 

suitable for sample collection. 

5.1.2.2 Place the probe/nozzle into the 

duct at the first sampling point and turn on 

the pump. A minimum vacuum of 15 in. Hg 

or 0.47 atmosphere between the critical 

orifice and pump is required to maintain 

critical flow. Sample for the time interval 

previously determined for that point. Move 

to the second point and sample for fhe time 

interval determined for that point; sample all 

points on the traverse in this manner. Keep 

ice around the impingers during the run. 

Complete the traverse and turn off the pump. 

Move to the next sampling port and repeat. 

Record the final dry gas meter reading. 

BILLING CODE J560-60-P 
65810 Federal Register / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

P.45 

Plant 

Sampling Site 

Total Micrograms catch(mCr) 

Avg dry gas meter temp FClta) 

Meter correction factor(Ym) 

Meter volume - actual cu ft(Vm)_ 

Barometric pressure in. Hg(Pbar) 

Start clock time 

Stop clock time_ 

Date_ 

Operator_ 

Run Number 

Stack radius(r) 

Avg delta p(p avg) 

Stack temp F(Ts) 

Leak rate before run_ 

Leak rate after run__ 

Stop meter volume 

Start meter volume 

REMARKS: 

POINT 

NO. 

SAMPLE 

(MIN/SEC) 

GAS METER 

TEMP (F) 

' 

POINT 

NO. 

SAMPLE 

(MIN/SEC) 

• 

GAS METER 

TEMP(F) 

Carn Cr (Tm+460) 

499.8(Ym)(Vm)(Pbar) 

Kg/Hr- (Cs)0.0001597r 1 p avg (Ts+460) 

Pbar(2873) 

Mg/Cubic Meter(Cs) (Optional)Kg/Hr 

Figure 306A-3. Chromium Constant Sampling Rate Field Data 

BILLING CODE 656O-60-C 
P.46 

TSIT / Vol. 58, No. 240 / Thursday, December 16, 1993 / Proposed Rules 

5.1.2.3 Post Test Leak Check. Remove the 

probe assembly and flexible tubing from the 

first impinger. Do not cover the nozzle. Seal 

the inlet tubs of the first impinger with a 

finger covered by clear plastic wrap and turn 

on the pump. Observe any leak rate on the 

dry gas meter. If the leak rate exceeds 0.02 

cfm, reject the run. If the leak rate is 

acceptable, take the probe assembly and 

impinger assembly to the sample recovery 

area. 

5.2 Sample Recovery. 

5.2.1 After the train has been moved to 

the sample recovery area, disconnect the 

tubing that joins the first impinger with the 

second. 

5.2.2 The first impinger jar is also used as 

the sample container jar. Unscrew the lid 

from the first impinger jar. Lift the inlet/ 

outlet tuba assembly almost out of the jar, 

and using the wash bottle, rinse the outside 

of fhe impinger tip that was immersed in the 

impinger jar with extra sampling reagent; 

rinse the inside of the tip as well. 

5.2.3 Recover the second impinger by 

removing the lid and pouring any contents 

from-the second impinger into the first 

impinger. Rinse the second impinger 

including the inside and outside of the 

impinger stem as well as any connecting 

plastic tubing with extra sampling reagent 

and place the rinse into the first impinger. 

5.2.4 Hold the nozzle and connecting 

plastic tubing in a vertical position so that 

the tubing forms a "U". Using the wash 

bottle, partially fill the. tubing with sampling 

reagent. (Keep a minimum of 100 ml of the 

sampling reagent for a blank analysis). Raise 

and lower the end of the plastic tubing 

several times to cause the reagent to contact 

the major portion of the internal parts of the 

assembly thoroughly. Do not raise the 

solution level too high or part of the sample 

will be lost. Place the nozzle end ofthe 

assembly over the mouth of the first impinger 

jar (sample container) and elevate the plastic 

tubing so that-the solution flows rapidly out 

of the nozzle. Perform this procedure three 

times. Next, repeat ths recovery procedure 

but allow the solution to flow rapidly out the 

open end of the plastic tubing into the first 

impinger jar. 

5.2.5 Place a piece of clear plastic wrap 

over the mouth of the first impinger jar. Use 

a standard lid and band assembly to seal the 

jar. Label the jar with the sample number and 

mark the liquid level to gauge any losses 

during handling.. 

5.3 Analysis. Sample preparation and 

analysis procedures are identical to Method 

306, Section 5.3. 

6. Calibration 

6.1 Dry Gas Meter. Calibrated by 

manufacturer or as specified in Method 5. 

6.2 GFAA Spectrometer. Same as Method 

306, Section 6.2. 

6.3 ICP Spectrometer. Same as Method 

306, Section 6.3. 

7. Quality Control 

Same as Method 306, Section 7. 

8. Calculations 

8.1 Pollutant Concentration. Calculate the 

concentration (CJ of chromium in milligrams 

per dry standard cubic meter (mg/dscm) as 

follows: 

Mc-xCT.,+460) ^ 

499.8 (Y.XV.XP^) 

where: 

Mcr=Micrograms of Cr in sample from 

Method 306, Eq. 308-1; 

Tm=Dry gas meter temperature in °F. 

Ym=Dry gas meter correction foctor. 

Vm=Dry gas meter volume in ft'. 

Pb_=Barometric pressure in inches Hg. 

8.2 Approximate Mass Emission Rate 

(Optional). Calculate an approximate mass 

emission rate for chromium in kilograms per 

hour using the following equation: 

Kg/hr = 0.0001597 r 

Apave(Ts-!-460) 

— •

 X S 

^ Pb-(28.73) 

Eq. 306A-3 

Where: 

r-Radius of stack in inches. 

Apave- Average of Ap values. 

T,=Stack temperature in "F. 

Pb_=Barometric pressure in inches Hg. 

(^Concentration of hexavalent chromium in 

mg/dscm. • 

Note: The emission rate is based on an 

average moisture content of 2 percent 

9. Bibliography 

1. F.R. Clay, Memo, Impinger Collection 

Efficiency—Mason Jars vs. Greenburg-Smith 

Impingers, Dec. 1989. 

2. Robin Segall, Draft Screening Method for 

Emissions from Chromium Plating 

Operations, Entropy Environmentalists, Jan. 

1988. 

3. F.R. Clay, Paper, A Simplified Method 

for Sampling for Hexavalent Chromium, May 

1990. 

4. F.R. Clay, Paper, Proposed Sampling 

Method 308A for the Determination of 

Hexavalent Chromium Emissions from 

Electroplating and Anodizing Facilities, May 

1992. 

Method 30813—Surfacs Tension 

Measurement for Tanks Uss_ eft HTtecorativo 

Chromium ElecSroplating and Anodizing 

Facilities 

1. Applicability and Principle 

1.1 Applicability. This method is 

applicable to all decorative chromium plating 

and anodizing operations where a wetting 

agent is used in the tank fo reduce emissions 

from the surface of the plating solution. 

1.2 Principle. During an electroplating or 

anodizing operation, gas bubbles generated 

during the process rise to the surface of tha 

liquid and burst. Upon bursting, tiny droplets 

of chromic acid become entrained in ambient 

air. The addition of a wetting agent to the 

tank bath reduces the surface tension of the 

liquid and diminishes the formation of these 

droplets. This method determines the surface 

tension of the bath using a stalagmometer or 

a tensiometer to confirm that there is 

sufficient wetting agent present. 

2. Apparatus 

2.1 Stalagmometer or Tensiometer. A 

commercially available stalagmometer, 

platinum ring detachment tensiometer or 

equivalent surface tension measuring device 

is required. 

3. Procedure 

3.1 The surface tension of ths tank bath 

may be measured by using a tensiometer or 

a stalagmometer. If a tensiometer is used, ths 

procedures specified in ASTM Method D 

1331-89, Standard Test Methods for Surface 

and Interfacial Tension of Solution of Surface 

Active Agents, shall be followed. If a 

stalagmometer is used, the instructions 

provided.with the measuring device must bs 

followed. 

3.2 Measurements of the bath surface 

tension must be made every 4 hours of tank 

operation. If the surface tension of the bath 

exceeds 40 dynes per centimeter for three 

consecutive four-hour periods, the interval 

between measurements must be reduced in 

one-hour increments until two consecutive 

measurements indicate the surface tension to 

be at or below 40 dynes per centimeter. If the 

activity level in the plating or anodizing tank 

is reduced, the time interval between 

measurements can be increased to a 

maximum of four hours as long as two 

consecutive measurements indicate tho 

surface tension is being maintained at or 

below 40 dynes per centimeter. 

IFR Doc. 93-30115 Filed 12-15-93; 8:45 am] 

BSLUNffl CODE S530-6O-P