National Emission Standards for Hazardous Air Pollutants for Source Categories: Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry and Other Processes Subject to the Negotiated Regulation for Equipment Leaks; Proposed Rule Clarifications

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[AD-FRL-5558-3]

RIN 2060-AC19

National Emission Standards for Hazardous Air Pollutants for

Source Categories: Organic Hazardous Air Pollutants From the Synthetic

Organic Chemical Manufacturing Industry and Other Processes Subject to

the Negotiated Regulation for Equipment Leaks; Proposed Rule

Clarifications

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule: Amendments.

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SUMMARY: On April 22, 1994 and June 6, 1994, the EPA issued the

National Emission Standards for Hazardous Air Pollutants for Source

Categories: Organic Hazardous Air Pollutants from the Synthetic Organic

Chemical Manufacturing Industry and Other Processes Subject to the

Negotiated Regulation for Equipment Leaks. This rule is commonly known

as the Hazardous Organic NESHAP or the HON. In June 1994, petitions for

review of the April 1994 rule were filed in the U.S. Court of Appeals

for the District of Columbia Circuit. The petitioners raised over 75

technical issues and concerns with drafting clarity of the rule.

Today's action proposes correcting amendments to the rule to address

the petitioners' issues.

Today's action proposes new definitions that apply to wastewater

and wastewater treatment and revised control and compliance provisions

for wastewater. A new compliance date of April 22, 1999, is being

proposed for process wastewater, heat exchange systems, in-process

equipment subject to the provisions of Sec. 63.149, and maintenance

wastewater. The proposed changes to these provisions are sufficiently

far reaching and complex to render those provisions effectively a new

rule. The EPA is also proposing a separate compliance date for

wastewater streams affected by the omission of nitrobenzene from the

list of compounds subject to the wastewater provisions. The proposed

revisions to the other provisions to the rule are corrections and

clarifications to ensure the rule is implemented as intended. Today's

amendments would also provide some additional compliance options that

would reduce the burden associated with the recordkeeping and reporting

requirements of the rule.

The proposed amendments to the rule will not change the basic

control requirements of the rule or the level of health protection it

provides. The rule requires new and existing major sources to control

emissions of hazardous air pollutants to the level reflecting

application of the maximum achievable control technology.

DATES: Comments. Comments must be received on or before September 25,

1996 unless a hearing is requested by September 5, 1996. If a hearing

is requested, written comments must be received by October 10, 1996.

Public Hearing. Anyone requesting a public hearing must contact the

EPA no later than September 5, 1996. If a hearing is held, it will take

place on September 10, 1996, beginning at 10:00 a.m.

ADDRESSES: Comments. Comments should be submitted (in duplicate, if

possible) to: Air and Radiation Docket and Information Center (6102),

Attention Docket Number A-90-19 (see docket section below), Room M-

1500, U.S. Environmental Protection Agency, 401 M Street, SW,

Washington, D.C. 20460. The EPA requests that a separate copy also be

sent to the contact person listed below.

Public Hearing. If a public hearing is held, it will be held at the

EPA's Office of Administration Auditorium, Research Triangle Park,

North Carolina. Persons interested in attending the hearing or wishing

to present oral testimony should notify Ms. JoLynn Collins, Waste and

Chemical Processes Group, U.S. Environmental Protection Agency,

Research Triangle Park, N.C. 27711, telephone (919) 541-5671.

Docket. Dockets No. A-90-19 through A-90-23, containing the

supporting information for the original NESHAP and this action, are

available for public inspection and copying between 8:00 a.m. and 5:30

p.m., Monday through Friday, at the EPA's Air and Radiation Docket and

Information Center, Waterside Mall, Room M-1500, first floor, 401 M

Street SW, Washington, DC 20460, or by calling (202) 260-7548 or 260-

7549. A reasonable fee may be charged for copying. Comments on the

proposed changes to the NESHAP may also be submitted electronically by

sending electronic mail (e-mail) to: [email protected].

FOR FURTHER INFORMATION CONTACT: For general questions, contact Dr.

Janet S. Meyer, Coatings and Consumer Products Group, at (919) 541-5254

or Mary Tom Kissell, Waste and Chemical Processes Group, at (919) 541-

4516. For technical questions on wastewater provisions, contact Elaine

Manning, Waste and Chemical Processes Group, telephone number (919)

541-5499. The mailing address for the contacts is Emission Standards

Division (MD-13), U.S. Environmental Protection Agency, Research

Triangle Park, North Carolina 27711.

SUPPLEMENTARY INFORMATION:

I. Regulated Entities and Background Information

A. Regulated Entities

The regulated category and entities affected by this action

include:

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Category Examples of regulated entities

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Industry.......................... Synthetic organic chemical

manufacturing industry (SOCMI)

units, e.g., producers of benzene,

toluene, or any other chemical

listed in Table 1 of 40 CFR part

63, subpart F.

Styrene-butadiene rubber producers.

Polybutadiene rubber producers.

Producers of Captafol;

Captan; Chlorothalonil;

Dacthal; and TordonTM acid.

Producers of Hypalon;

Oxybisphenoxarsine/1,3-diisocyanate

(OBPA); Polycarbonates;

Polysulfide rubber; Chlorinated

paraffins; and Symmetrical

tetrachloropyridine.

Pharmaceutical producers.

[[Page 43699]]

Producers of Methylmethacrylate-

butadiene-styrene resins (MBS);

Butadiene-furfural cotrimer;

Methylmethacrylate-acrylonitrile-

butadiene-styrene (MABS) resins;

and Ethylidene norbornene.

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This table is not intended to be exhaustive but, rather, provides a

guide for readers regarding entities likely to be interested in the

revisions to the regulation affected by this action. Entities

potentially regulated by the HON are those which produce as primary

intended products any of the chemicals listed in table 1 of 40 CFR part

63, subpart F and are located at facilities that are major sources as

defined in section 112 of the Clean Air Act (CA). Processes subject to

the negotiated regulation for equipment leaks (i.e., 40 CFR part 63,

subpart I) are also potentially affected by this action. Processes

subject to 40 CFR part 63, subpart I are producers of any of the

products listed in 40 CFR part 63, subpart I that are located at

facilities that are major sources as defined by section 112 of the CA.

To determine whether your facility is regulated by this action, you

should carefully examine all of the applicability criteria in 40 CFR

63.100 and 40 CFR 63.190. If you have questions regarding the

applicability of this action to a particular entity, consult the person

listed in the preceding FOR FURTHER INFORMATION CONTACT section.

B. Copies of Regulatory Text

The proposed regulatory text is not included in this Federal

Register action because of the length and complexity of the amendments

to the rule. The proposed changes to the rule are discussed fully in

this preamble. The proposed amendments to the rule are available in

Docket A-90-19 or by request from the Air and Radiation Docket and

Information Center (see ADDRESSES) or the EPA contact person listed in

the preceding FOR FURTHER INFORMATION CONTACT section. The proposed

rule amendments may also be obtained over the Internet at http://

ttnwww.rtpnc.epa.gov or from the EPA's Technology Transfer Network

(TTN). The TTN is a network of electronic bulletin boards developed and

operated by the Office of Air Quality Planning and Standards. The

service is free, except for the cost of a phone call. Dial (919) 541-

5742 for up to a 14,400 bits per second modem. Select TTN Bulletin

Board: Clean Air Act Amendments and select menu item Recently Signed

Rules. If more information on TTN is needed, contact the systems

operator at (919) 541-5384.

C. Electronic Submission of Comments

Comments on the proposed changes to the NESHAP may also be

submitted electronically by sending electronic mail (e-mail) to: a-and-

[email protected]. Electronic comments must be submitted as an

ASCII file avoiding the use of special characters and any form of

encryption. Comments will also be accepted on diskette in WordPerfect

5.1 or ASCII file format. All comments in electronic form must be

identified by the docket number A-90-19. No Confidential Business

Information (CBI) should be submitted through e-mail. Electronic

comments may be filed online at many Federal Depository Libraries.

D. Background on Rule

On April 22, 1994 (59 FR 19402), and June 6, 1994 (59 FR 29196),

the EPA published in the Federal Register the NESHAP for the SOCMI, and

for several other processes subject to the equipment leaks portion of

the rule. These regulations were promulgated as subparts F, G, H, and I

in 40 CFR part 63, and are commonly referred to as the hazardous

organic NESHAP, or the HON. Since the April 22, 1994 notice, there have

been several amendments to clarify various aspects of the rule. Readers

should see the following Federal Register notices for more information:

September 20, 1994 (59 FR 48175); October 24, 1994 (59 FR 53359);

October 28, 1994 (59 FR 54131); January 27, 1995 (60 FR 5321); April

10, 1995 (60 FR 18020); April 10, 1995 (60 FR 18026); December 12, 1995

(60 FR 63624); February 29, 1996 (61 FR 7716); and June 20, 1996 (61 FR

31435).

In June 1994, the Chemical Manufacturers Association and Dow

Chemical Company filed petitions for review of the promulgated rule in

the U.S. Court of Appeals for the District of Columbia Circuit,

Chemical Manufacturers Association v. EPA, 94-1463 and 94-1464 (D.C.

Cir.) and Dow Chemical Company v. EPA, 94-1465 (D.C. Cir). The

petitioners raised over 75 technical issues on the rule's structure and

applicability. Issues were raised regarding details of the technical

requirements, drafting clarity, and structural errors in the drafting

of certain sections of the rule. Today's proposed revisions address all

of the issues raised by CMA and Dow on the April 1994 rule.

With today's action, EPA is proposing clarifying and correcting

amendments to subparts F, G, H, and I of part 63. Following review and

consideration of comments received on today's proposed revisions in

accordance with a settlement agreement reached with CMA and Dow, EPA

will take final action on the proposed amendments by December 31, 1996.

As of the date of signature of this proposal, the section 113(g) notice

process was not yet complete, and, therefore, the settlement was not

final. However, EPA believes it is important to publish the proposed

rule in accordance with the schedule provided in the draft settlement

agreement because of the pendency of the compliance date. When a

settlement becomes final, it will govern the date of signature of the

final rule. As discussed in section III.B, sources subject to the rule

would be expected to be in compliance with the amended provisions for

heat exchange systems, maintenance wastewater, in-process equipment

subject to Sec. 63.149, and process wastewater by April 22, 1999.

Equipment subject to the other provisions of the rule would be expected

to be in compliance by April 22, 1997, unless a compliance extension is

granted. The EPA anticipates finalizing some portions of the proposed

rule earlier than December 31, 1996. For example, the proposal would

eliminate the need for filing some implementation plans that would

otherwise be due December 31, 1996, and would allow the filing of

requests for compliance extensions up to 4 months before the April 1997

compliance date. The EPA will attempt to take final action on these

provisions as soon as possible after the close of the comment period in

order to give sources as much lead time as possible.

II. Overview of Changes to Rule

With today's proposed action, EPA is proposing clarifying and

correcting amendments to subparts F, G, H, and I of 40 CFR part 63.

These proposed amendments include an extension of the compliance date

to April 22, 1999 for process wastewater, heat exchange systems,

maintenance wastewater, and in-process equipment subject to the

provisions of Sec. 63.149. These sections of the rule would be

extensively revised by

[[Page 43700]]

today's proposal. The proposed revisions are intended to remove any

ambiguity and clearly convey EPA's intent, to make the rule easier to

read and implement, and to increase flexibility for the source.

The proposed amendments would also set a separate compliance date

for wastewater streams affected by the omission of nitrobenzene from

table 9 of subpart G. A three year compliance date is being proposed

for process wastewater streams that are subject to control requirements

due to the presence of nitrobenzene due to an error in the April 22,

1994 rule. The compliance date for other emission points remains April

22, 1997.

The proposed revisions to the wastewater sections of the rule have

been redrafted to improve organizational structure and drafting

clarity. One significant clarification would be to the definition of

``wastewater'' which would be revised to incorporate the concept that

only when water is discarded from a process is it subject to the HON

wastewater provisions. Additional changes would be made to the

wastewater provisions to: (1) ensure that streams traveling from one

piece of process equipment to another would be handled appropriately to

avoid emissions to the environment, and (2) ensure that the changes in

the wastewater definitions would not permit sources to dilute their

waste streams prior to the point the streams are considered wastewater,

thus avoiding control requirements. If a HON source owner or operator

wished to ship waste off-site for treatment, the owner or operator may

only ship to a facility that has certified that it will treat the waste

to the standard required by the HON.

In contrast to the significant redrafting of the wastewater

provisions, minor edits are proposed for other sections of the rule. In

addition to removing ambiguity and increasing flexibility for the

source, some revisions would reduce the reporting and recordkeeping

burden for sources. The reporting and recordkeeping revisions would

include changes which: reduce the number of copies of reports that must

be submitted to EPA and the States; provide for alternative, less

frequent recordkeeping of monitoring data where sources show no

violations for prolonged stretches of time; and remove the requirement

for most sources to file an implementation plan.

III. Compliance Date Changes and Other General Changes

A. Applicability of Rule

1. Designation of the Source

In today's amendments, EPA is proposing revisions to Sec. 63.100,

paragraphs (e) and (f) to clarify which equipment is included within

the scope of the source regulated by this rule. These revisions are

being proposed because the drafting and structure of paragraphs (e) and

(f) in Sec. 63.100 have caused confusion and raised concerns as to

whether other equipment or activities not listed are included in the

source. The proposed revisions to these paragraphs are intended to

improve rule clarity.

The present wording of paragraph (e) of Sec. 63.100 incorporates,

inter alia ``wastewater and associated treatment residuals'' in the

source. This text does not state explicitly whether waste management

units, heat exchange systems, or maintenance wastewater are included in

the source. The present designation of the source also does not include

control devices or recovery devices used to comply with this rule. Some

industry representatives have expressed concern that these types of

equipment could be considered subject to section 112(g) of the Act

because the equipment is not part of a source subject to a section

112(d) standard. To address this concern, the EPA is proposing to

revise this paragraph by listing the specific categories of equipment

and types of wastewater included in the source and by adding control

and recovery devices to the items designated to be included in the

source. The EPA is also proposing to revise paragraph (f) of

Sec. 63.100 to reverse the drafting structure to state that the listed

items are included in the source, but are not subject to the control

requirements of the rule. Based on discussions with industry, EPA has

found that reversing the structure would make it more understandable to

the regulated community and would reduce the chance of incorrect

interpretation.

2. Definition of Chemical Manufacturing Process Unit (cmpu)

The EPA is proposing amendments to clarify the definition of cmpu

and the definition of unit operation. The proposed revisions consist of

clarifying that a cmpu consists of two or more unit operations and

correcting the definition of unit operation to refer to the defined

term ``distillation units'' instead of distillation columns. These

proposed changes are expected to clarify the determination of

applicability for facilities with integrated operations.

3. Applicability of Rule to Storage Vessels Located in a Tank Farm or

Marine Terminal

The EPA is proposing amendments to clarify the applicability of the

rule to storage vessels located in tank farms and marine tank farms.

The proposed amendments being added as Sec. 63.100(g)(3) would

explicitly specify the procedures to be followed to assign the storage

vessels to a process and then to determine the applicability of the

rule. Due to an oversight, the provisions currently in Sec. 63.100(g)

of subpart F do not include instructions regarding allocation of tanks

in remote locations.

Following issuance of the 1994 rule, EPA received inquiries

regarding the applicability of the rule to storage vessels that are

physically remote from the cmpu, but are located at the major source

and connected to the cmpu by piping. Some of the inquiries raised

questions regarding the distinction between storage vessels used for

product storage and vessels used more for purposes of facilitating

product distribution. Other inquiries concerned applicability of the

rule where a dedicated product (or raw material) storage tank was

located in the tank farm. Following a review of the rule language and

the underlying analyses for the rule, EPA concluded that the record on

this point was ambiguous and that the rule should be amended to clarify

these issues. The proposed revisions to Sec. 63.100(g) are based on the

concepts presently used in the rule for assignment of equipment that is

shared among several cmpus and on a basic assumption used in developing

the rule that, which is typically a cmpu, includes raw material and

product storage vessels.

The proposed provisions assign a storage vessel to a cmpu based on

three decision rules. First, a storage vessel in a tank farm is

considered to be part of a cmpu only if the cmpu does not have another

intervening, storage vessel for product (or raw material). Where there

is an intervening storage vessel, the boundary of the cmpu would end at

that intervening storage vessel (and any associated transfer operations

and other equipment) and would exclude the tank farm storage vessel.

Second, if two or more cmpus (of those using the tank farm storage

vessel) lack a co-located storage vessel, then the storage vessel at

the tank farm would be assigned to a cmpu, according to the concepts of

predominant use specified in Sec. 63.100(g)(2). Third, if only one cmpu

(of those that use the remote storage

[[Page 43701]]

vessel) lacks a co-located product (or raw material) storage vessel,

then the remote storage vessel would be assigned to that cmpu.

The EPA expects that this assignment procedure will result in

assignment of storage vessels in a manner consistent with normal

management of facility operations. Specifically, it is expected that

storage vessels that are an integral part of operation of a cmpu

subject to the HON will be regulated under the HON and that storage

vessels that are used to facilitate product distribution will be

regulated as part of the organic liquids distribution source category

and not under the HON.

4. Determination of Applicability of the Rule to Equipment Shared Among

Integrated Operations

Today's proposed amendments include clarifying changes to the

equipment assignment procedures specified in Sec. 63.100 (g), (h), and

(i) for storage vessels, transfer racks, and distillation units. Since

the HON was issued in April 1994, EPA has received inquiries regarding

the correct interpretation of the text in these paragraphs. Based on

these inquiries and discussions with industry representatives, EPA has

concluded that the questions and concerns are due to minor wording

differences in paragraphs (g) and (h) and the absence of an explicit

statement that paragraph (i) specifies the assignment procedures for

shared distillation columns.

Today's proposed amendments would make the wording and structure of

these paragraphs parallel. Specifically, the proposed revisions would

make the wording of paragraphs (g)(1) and (h)(1) parallel to the

wording in paragraphs (g)(2) and (h)(2), respectively. The proposed new

paragraphs would add provisions to paragraph (i) that address the

assignment of dedicated distillation units and would clarify that the

assignment procedure is for distillation units shared among several

processes. The proposed revisions also clarify the wording of the

requirement to reassess the assignment of the equipment whenever there

is a change in the use of the equipment.

5. Revision to Table 2 of Subpart F List of Regulated Hazardous Organic

Air Pollutants (HAP's)

The EPA has received numerous requests for clarification of the

definition of ``Polycyclic organic matter'' (POM) in table 2 of subpart

F. The nature of these requests indicates that there is confusion

regarding the scope of the definition. To eliminate this confusion, EPA

is proposing to revise table 2 of subpart F to list the specific

compounds that are to be regulated as POM in the HON. The specific

compounds being listed are consistent with the historical working

definition of POM, which emphasizes emissions from incomplete

combustion and pyrolysis processes (49 FR 31680). This change is

expected to improve rule clarity.

B. Compliance Dates

1. Compliance Date Extension for Wastewater Provisions

With respect to compliance dates, the final rule promulgated on

April 22, 1994, provided that existing sources must be in compliance

with the requirements of subparts F and G no later than April 22, 1997,

unless an extension is granted in accordance with Sec. 63.151(a)(6) of

subpart G or Sec. 63.6(i) of subpart A.

Today's proposal would change the compliance date provisions

applicable to HON sources in two significant respects. These changes

are included in Sec. 63.100(k)(2) of today's proposed rule. First,

Sec. 63.100(k)(2)(ii) would set a new compliance date of April 22,

1999, for heat exchange systems, maintenance wastewater, in-process

equipment subject to Sec. 63.149, and process wastewater. Second,

Sec. 63.100(k)(2)(ii)(A) would set a new compliance date that is three

years from the date of final publication for process wastewater streams

and in-process equipment subject to Sec. 63.149 that are subject to

control requirements due to the contribution of nitrobenzene to the

annual average concentration of Table 9 compounds.

The new compliance date for heat exchange systems, maintenance

wastewater, in-process equipment subject to Sec. 63.149, and process

wastewater is being proposed because the changes to these provisions

applicable to HON sources are sufficiently far reaching and complex to

render those provisions effectively a new rule warranting a new

compliance date. In contrast, the changes to other portions of the

April 22, 1994, rule are less extensive, are more in the nature of

corrections and clarifications, and EPA does not believe they

jeopardize sources' ability to meet the April 1997 compliance date.

Section 112(i)(3) of the Act provides that existing sources are to

be in compliance with applicable emission standards ``as expeditiously

as practicable, but in no event later than 3 years after the effective

date of such standard.'' The April 22, 1994, final rule specified a

compliance date applicable to wastewater streams and heat exchange

systems that was three years from the issuance of that rule. Section

112(d)(6) provides authority for the Administrator to revise the

emission standards issued under section 112 ``no less often than every

8 years.'' EPA believes that the authority to revise the standards

inherently includes the authority to set new compliance dates for

revised rules. Any other approach would require existing sources to

come into compliance with potentially extensive revisions immediately,

just as if they were new sources. Obviously, Congress provided EPA

discretion to set a compliance date for existing sources of up to three

years in order to provide time for retrofitting of controls where

necessary. Thus, due to the extensive nature of the revisions to the

provisions applicable to heat exchange systems and wastewater streams,

the creation of requirements for in-process equipment subject to

Sec. 63.149, and the proximity to the April 1997 compliance date in the

original rule, EPA is setting a new compliance date for those

provisions.

EPA believes that two years from the otherwise applicable

compliance date will be sufficient for all sources to come into

compliance with the new wastewater and in-process equipment provisions.

However, should any source be unable to meet that compliance date

because of the need to install controls that cannot be installed by

that date, such source may request an extension of up to one year in

accordance with Sec. 63.151(a)(6).

The new three year compliance date in Sec. 63.100(k)(2)(ii)(A) for

process wastewater streams and in-process equipment subject to

Sec. 63.149 that are subject to control requirements due to the

presence of nitrobenzene, is being proposed because of an error in the

April 22, 1994, rule. Nitrobenzene is a HAP included on the section

112(b) list. However, due to an oversight, it was not included on table

9 (which lists HAPs subject to the wastewater provisions) in the April

22, 1994, rule. Thus, there was confusion as to whether or not the

presence of nitrobenzene in wastewater streams should be a factor in

determining whether such streams were Group 1 or Group 2. This error

was corrected in the December 12, 1995, correction notice (60 FR 63624

(December 12, 1995)). However, due to the extensive changes to the

wastewater provisions and the uncertainty caused by the initial

omission of nitrobenzene from table 9, EPA is proposing to set a new

compliance date for wastewater streams affected by the error.

EPA seeks comment on its proposal to set new compliance dates in

Sec. 63.100,

[[Page 43702]]

paragraphs (k)(2)(ii) and (k)(2)(ii)(A), and in particular seeks

comment on the appropriateness of the particular dates proposed.

2. Timing of Compliance Extension Requests

The April 22, 1994, rule requires that requests for compliance

extensions be submitted one year prior to the otherwise applicable

compliance date. The EPA is proposing to revise this requirement, which

is in Sec. 63.151(a)(6)(i), to allow submittal of requests up to 120

days prior to the compliance date. The EPA is also proposing to add a

new paragraph (iv) to Sec. 63.151(a)(6) that would allow requests

during the last 120 days before the compliance date if the need arose

during that 120 days and if the need was due to circumstances beyond

the reasonable control of the owner or operator. Submission of a

compliance extension request would not stay the applicability of the

rule to the applicant source during the pendency of the request.

The EPA is proposing these revisions in recognition that review of

most requests for compliance extensions can be completed within 4

months and it is unlikely that it would require 12 months to complete

review of the request. The EPA is also proposing to allow submittal of

extension requests up to the compliance date in recognition that

unforeseen difficulties, such as construction or operational

difficulties, can arise in the last moments of compliance planning. The

proposed provisions in Sec. 63.151(a)(6)(iv) are also considered

necessary in the case of this rule because it is unlikely that these

proposed revisions will be final more than 4 months prior to the April

22, 1997, compliance date for certain control requirements. Any changes

in the wording or requirements of the final rule could affect

compliance planning for a source. Therefore, EPA believes that it is

necessary to provide some opportunity for applications for compliance

extension requests after the date that is 4 months prior to the

compliance date.

3. Clarification of Compliance Periods

The proposed revisions to subpart F also would add a new paragraph

(k)(9) to Sec. 63.100, and a new paragraph (g) to Sec. 63.162 to

clarify that when the rule specifies a period of time for completion of

required tasks (e.g., weekly, monthly, quarterly, annual), this refers

to standard calendar periods unless it is specified otherwise in the

section or paragraph that imposes the requirement. The current rule

does not specify this, and this text is being added to the rule to

remove any potential for ambiguity. The new Sec. 63.100(k)(9) and

Sec. 63.162(g) also provide that time periods may be changed by mutual

agreement between the owner or operator and the Administrator, as

provided in subpart A of this part. Finally, this new set of provisions

also provides that if the rule requires completion of a task during

each of multiple successive periods, an owner or operator may perform

the required task at any time during the specified period, provided the

task is conducted at a reasonable interval after completion of the

previous task. When the rule was originally drafted it was assumed that

this could be done, but an oversight in drafting language specifying

this was omitted from the rule.

C. Heat Exchanger Provisions

In today's amendments, the EPA is proposing new requirements for

monitoring heat exchange systems for leaks of process fluids into

cooling water. The proposed Sec. 63.104 would replace the existing

provisions in Sec. 63.104 of subpart F. The proposed revisions are

being made to address issues with the existing provisions related to

the availability of monitoring methods with sufficient analytical

sensitivity, lack of flexibility in some of the requirements, and the

burden associated with the monitoring requirements. The major revisions

to this section of the rule and the reasons for the changes are

described below.

1. Conditions Exempted From Monitoring Requirements

The existing provisions of Sec. 63.104 exempt two categories of

heat exchange systems from the monitoring requirements. The first

exempt category is heat exchange systems operated with a greater

pressure on the cooling water side. These systems were exempted because

any leakage would be into the process fluid, not into the cooling

water, so it is not necessary to monitor the cooling water for the

presence of process fluids. The second exempted category is once-

through heat exchange systems operating with a National Pollutant

Discharge Elimination System (NPDES) permit allowable discharge limit

of less than 1 ppm. These two categories were exempted because the

provisions of Sec. 63.104 would impose a redundant requirement. The

proposed revisions to Sec. 63.104 would extend this exemption to three

additional cases. First, facilities with NPDES permits that require

monitoring of a parameter or condition that would detect a leak of

process fluids and requires the owner or operator to report and correct

leaks when the parameter or condition exceeds the normal range. For

facilities with such NPDES permit the requirements in Sec. 63.104 would

be redundant with the NPDES permit requirement. Second, systems where

there is an intervening cooling fluid (containing less than 5% by

weight of the applicable HAP's) between the process and the cooling

water would be exempted. In these systems, the monitoring requirements

of Sec. 63.104 are unnecessary because leaks of process fluids would be

detected in intervening process equipment before there could be a leak

into the cooling water. The third exempt category is systems used to

cool process fluids that contain less than 5% by weight HAP's. This

last category of heat exchange systems is being added because it is

consistent with the intent that provisions only require monitoring when

HAP's are present in concentrations greater than 5% by weight.

2. Hazardous Air Pollutants Subject to Monitoring Requirements

The April 22, 1994, rule requires owners or operators of

recirculating heat exchange systems to monitor for organic HAP's listed

in table 2 of subpart F, except for four water-reactive HAP's. Today's

proposed amendments would reduce the number of organic HAP's subject to

the monitoring requirement for these recirculating systems. The revised

list of organic HAP's subject this requirement is provided in proposed

table 4 of subpart F. There are no proposed changes to the organic

HAP's subject to the monitoring requirement (found in table 9 of

subpart G) for once-through cooling systems.

Since the April 22, 1994, rule was issued, EPA has received

inquiries regarding the basis for the requirement to monitor for table

2 compounds in cooling water of recirculating heat exchange systems.

Some industry representatives have questioned the inclusion of

compounds that are not on table 9 of subpart G and have argued that

cooling towers are ineffective at air stripping relatively nonvolatile

compounds (i.e., compounds not in table 9) listed in table 2 of subpart

F. In response to these questions, EPA modeled the potential air

emissions of each table 2 compound from a process cooling tower. This

analysis indicated that there are about 23 compounds listed in table 2

of subpart F that have no, or very insignificant, potential for

emissions. Examples of organic HAP compounds that were found to have

little potential for volatilization in a cooling tower are ethylene

glycol and acrylamide. Based on this modeling

[[Page 43703]]

analysis, EPA concluded that it would be appropriate to apply

monitoring requirements to some compounds on table 2 of subpart F as

well as to compounds listed on table 9 of subpart G. This conclusion is

based on finding that there are a number of compounds which have an

insignificant potential for emission from typical wastewater collection

and conveyance systems but which can have fairly substantial losses

when sent through a process cooling tower. Proposed table 4 lists the

compounds modelled to have significant emission potential when sent

through a process cooling tower. Also, in order to limit monitoring to

only those compounds calculated to have significant emission potential

and to eliminate unnecessary burden, proposed table 4 lists specific

glycol ethers instead of the family of compounds. This was done because

different glycol ethers have significantly different physical

properties.

3. Added Flexibility to Monitoring Requirements

The rule currently requires monitoring of cooling water using any

EPA approved method in 40 CFR part 136 as long as the method can

measure concentrations of the compound as low as 1 ppm. Since issuance

of the rule in April 1994, EPA has received information that the

methods in 40 CFR part 136 are not available for some HAP's and that

the additional requirement for measurement sensitivity further reduces

the number of available methods. To correct these implementation

problems, EPA is proposing the following revisions to Sec. 63.104.

The proposed Sec. 63.104 includes provisions that would allow

monitoring of a surrogate indicator of a heat exchanger leak in lieu of

monitoring for specific organic HAP's in the cooling water. This new

option is being proposed because of analytical limitations and costs of

measuring some of the organic HAP's regulated by this provision and

because, in some cases, the intent of this section can be met by using

a surrogate indicator. Proposed Sec. 63.104 also includes provisions

that would allow monitoring of a surrogate indicator such as ion

specific electrode monitoring, pH, or other physical properties of the

cooling water or process operations. The EPA expects that this option

would be useful in cases where there are no EPA approved methods for

any compounds in the process or where there are easily measured process

parameters that provide a reliable indication of heat exchanger leaks.

Under this new alternative, an owner or operator would prepare and

implement a monitoring plan that would specify the parameters that

would be monitored and the criteria which, if exceeded, would

constitute a leak. The owner or operator would have to update the

monitoring plan anytime a substantial leak is detected by methods other

than those described in the plan and identify the methods in the plan

that did not detect the leak. These provisions were developed based on

consideration of existing programs and work practices at some SOCMI

facilities for detecting leaks of process fluids into cooling water. It

is expected that this alternative will be less burdensome than the

existing requirements and may allow use of existing procedures to meet

this requirement.

The EPA is also proposing to revise the minimum sensitivity

requirement for analytical methods from 1 ppm to 10 ppm. This change is

being proposed to increase the number of methods available for use in

the organic HAP monitoring alternative and to reduce the cost of this

monitoring. The EPA selected 10 ppm as the minimum sensitivity for the

method based on consideration of the detection limits for the EPA 600

series methods.

The EPA also realizes that even with this increase in the minimum

sensitivity to 10 ppm, there will be a few compounds for which there is

no approved quantitative analysis method. Because of this problem, the

existing provisions of Sec. 63.104(b) were revised to specify that the

monitoring of organic HAP's may be to monitor a subset (one or more) of

the organic HAP's in the cooling water. The EPA expects that this

change in the wording of the organic HAP monitoring alternative will

allow monitoring of the compound (or compounds) that can be measured

and will remove the appearance that the monitoring has to be capable of

detecting every HAP at the minimum sensitivity.

4. Miscellaneous Clarifications to Sec. 63.104

Today's proposed Sec. 63.104 would allow sampling across the

cooling tower, at the entrance and exit of each heat exchange system,

or any combination of heat exchangers (e.g., across a cmpu or at a

plant site). The April 1994 rule specified that the sampling was to be

across the cooling tower. The EPA is proposing to revise this

requirement because of concerns that have been expressed that the

present rule is inflexible and requires monitoring at a location that

is less cost effective. The April 1994 rule specified monitoring across

the cooling tower because of public comments received on the proposed

rule. Today's proposed revisions differ from the original proposed

language in that there is more flexibility in the selection of sampling

locations and the terminology has been clarified in that the rule now

specifically defines the convention for entrance and exit of systems.

Today's proposed revisions to Sec. 63.104 include clarification and

correction of the existing language that defines a leak. The wording of

the existing provision in Sec. 63.104(b)(1)(v) has resulted in

inquiries regarding the proper interpretation. Proposed

Sec. 63.104(b)(6) specifies the type of statistical test as well as the

significance level in defining a leak. The EPA requests comment on

whether the revised language will appropriately identify and minimize

the number of false positive indications of a leak.

The proposed Sec. 63.104 would also revise the delay of repair

provisions to allow delay until the next shutdown if a shutdown is

planned within 2 months of determination that delay of repair is

necessary. The proposed revisions to Sec. 63.104 would also allow delay

of repair up to a maximum of 120 days if the necessary parts or

personnel are not available. The April 1994 rule only allows delay of

repair when it can be demonstrated that immediate shutdown for repair

would create more emissions than the emissions that would result from

delaying repair of the leaking heat exchanger until the next shutdown.

The proposed revisions to the delay of repair provisions of the rule

are being made to make these provisions workable and to minimize debate

over modeling of emissions from heat exchanger systems.

D. Control Alternatives

1. Routing Emissions to a Process

The EPA proposes to add provisions to the rule to allow routing of

emissions to a process or fuel gas system as a means of compliance

where appropriate. Currently, subparts G and H are not amenable to use

of recycling to a process or fuel gas system as a means of compliance

with the control requirements. These revisions would allow use of this

compliance approach without defining the process or fuel gas system as

a control device and imposing, in turn, control device monitoring and

recordkeeping requirements. This change is being made to encourage use

of pollution prevention control approaches and to reduce the monitoring

and recordkeeping burden of the rule.

The proposed amendments consist of: (1) revisions to the

definitions for

[[Page 43704]]

process vent and vapor balancing system and addition of definitions for

fuel gas and fuel gas system in subpart F; (2) amendments to the

storage vessels and transfer operations provisions in subpart G; and

(3) addition of a definition of ``route to a process'' and inclusion of

this option in the list of control requirements in subpart H. The

definitions for fuel gas and fuel gas system are based on the

definitions recently promulgated in subpart VV, part 60 and in subpart

CC, part 63 (Refinery NESHAP). The proposed definitions have been

reworded slightly to remove the refinery-specific references and to

refer to combustion devices more generally instead of listing specific

types of combustors.

The proposed amendments to subpart G to allow recycling to a

process for storage vessels and transfer operations require that the

recycled material be used or consumed in the same manner as a material

that fulfills the same function in the process, be transformed into a

material that is not an organic hazardous air pollutant, or be

recovered or incorporated into a product. These restrictions are placed

on this option to avoid the potential for sham claims of recycling. The

proposed provisions for storage vessels also include provisions to

allow limited by-pass of the process or fuel gas system during periods

of maintenance or repair of the process or fuel gas system. These

provisions are necessary because these storage vessels would not

necessarily be emptied during these maintenance periods and emissions

would continue from the vessel. Since more emissions would result if

the rule were to require emptying and degassing of storage vessels

during these periods than if the vessels were allowed to vent to the

atmosphere, provisions are being added to Sec. 63.119 to allow by-pass

of the fuel gas system or process during these periods. These

provisions specify the conditions that must be met during these by-pass

periods to minimize emissions. Similar provisions are not being

proposed for transfer operations because it is not believed to be

necessary. Loading operations can normally be postponed until the

process or fuel gas system is operational again.

The proposed amendments to subpart H consist of addition of a

definition of ``route to a process'' and changes to the control options

for pumps, compressors, etc. The definition of ``route to a process''

incorporates the key concepts used in subpart G provisions for storage

vessels and transfer operations. No provisions have been included in

the proposed amendments to subpart H to allow by-pass during periods of

maintenance or repair of the process or fuel gas system. The EPA does

not believe that parallel provisions are needed for equipment leaks.

2. Lower Bound Concentration Performance Standard

The EPA is proposing to add an alternative performance standard

limit of 20 parts per million by volume concentration limit for

noncombustion control devices used to comply with the process vent,

storage vessel, and wastewater provisions in subpart G and the

equipment leak provisions of subpart H. This option would be in

addition to the present performance standard of 98 or 95 percent

removal of total VOC or HAP, respectively, in these sections of the

rule. This lower bound concentration standard is being added to those

sections of the rule where EPA believes there would not normally be

significant amounts of dilution air and any attempts to circumvent

could be detected. The EPA is proposing this change to the rule to

provide a lower bound concentration level for use in cost effective

design of control devices and recovery devices such as carbon adsorbers

and condensers.

This lower bound concentration performance standard is proposed to

be added to the rule to reflect actual performance of these control

devices and to make the rule's requirements consistent with the

underlying cost and emission analyses for this rule. Most recovery

devices (e.g., condensers, adsorbers, etc.) are designed to achieve a

specific outlet concentration for a maximum loading scenario for a

stream with specific characteristics. The specific outlet concentration

of a given system is a function of the equilibrium and kinetic limits

for the technology and the characteristics of the gas stream and the

cost of the system. For any given design, these devices will typically

reduce emissions to the same concentration level over a relatively wide

range of inlet concentrations. Thus, when the inlet concentration is

substantially below the design maximum loading conditions (and begins

to approach the residual level in the outlet stream) the recovery

device efficiency will decrease. When this occurs the outlet

concentration is the same or lower than the outlet concentration during

maximum loading conditions. The cost and emission control estimates

used in development of this rule were based on maximum design loading

conditions and did not reflect operations over the full range of

potential operating conditions for the SOCMI industry. Therefore, it is

necessary to specify a lower bound concentration performance level in

addition to the removal efficiency in the rule to ensure that this rule

is implemented as intended. Where EPA considered the use of this

alternative to be appropriate, the proposed amendments would add

provisions to specific sections to allow use of the 20 ppm standard.

This addition of a lower bound concentration limit to the

performance standard will also encourage use of devices that recover

and allow for reuse of materials and will remove an inequity between

requirements for different types of control equipment. With this

additional control alternative, the requirements for process vents,

storage vessels, vapor control devices applied to certain waste

management units, and equipment leaks will be consistent with the

requirements for transfer racks.

This lower bound concentration standard is not being allowed as an

option for compliance with the enclosed process unit alternative in

Sec. 63.172 of subpart H or with the control requirements for surface

impoundments subject to Sec. 63.134 of subpart G. The use of this lower

bound concentration limit is considered inappropriate in those

situations because of the large volumes of dilution air involved.

3. Recapture Devices

The EPA is proposing to revise the rule to clarify the requirements

for equipment such as adsorbers, condensers, and scrubbers that are

used to recover materials (but not primarily for use, reuse, or sale),

and are used to meet the control requirements. The proposed amendments

introduce a new term, ``recapture device'', to identify these devices,

which capture emissions and then send the material for ultimate

disposal, revise the definition of control device to include this

concept, and revise various sections of the rule to refer to recapture

devices. Currently, the rule allows the use of control devices and

recovery devices and specifies the applicable monitoring and

recordkeeping requirements by type of equipment (e.g., adsorbers,

etc.). However, the rule does not indicate how to treat a non-

combustion device that is not used as a recovery device (as defined in

the rule).

The EPA is proposing to revise the rule in this manner in order to

address the regulatory void for non-combustion/non-recovery devices

while preserving the approach used in this rule (and earlier rules) to

differentiate between process and control in this industry. The

existing definitions in the rule for recovery device and control device

reflect the regulatory approach used in

[[Page 43705]]

the NSPS standards for process vents associated with distillation

operations, air oxidation reactors, and other reactors. Under this

approach, equipment is considered to be part of the process if the

recovered materials are used, reused, or sold. The NSPS standards for

process vents and the HON process vent provisions treated all

condensers, adsorbers, scrubbers as ``recovery devices'' and never

considered situations where this equipment could be used to capture the

emissions and then send the material for ultimate disposal. Since these

uses of these types of equipment do occur and the approach used to

distinguish between process and control was an integral part of the

data analysis used to support this rule, the EPA concluded that the

best approach would be to define a new term to identify this additional

category of equipment and to explicitly identify this equipment and the

monitoring requirements in the rule.

4. Industrial Furnaces

In today's amendments, the EPA is proposing to include RCRA-

regulated industrial furnaces under the HON's provisions for boilers.

This change is being proposed because industrial furnaces, like other

RCRA-regulated combustion devices, are subject to RCRA requirements

which accomplish the same purpose as some HON provisions. For example,

owners and operators are already required to demonstrate that

industrial furnaces are capable of achieving the RCRA-required

destruction and removal efficiency. A second performance test under the

HON is not considered necessary. By amending the definition of

``boiler'' to include industrial furnaces, the rule would treat

industrial furnaces similarly to other RCRA-regulated combustion

devices.

The EPA has chosen to include industrial furnaces within an

existing HON definition, the definition of ``boiler'', rather than

creating separate regulatory provisions for industrial furnaces

throughout subparts F, G and H. This decision is based on a desire to

avoid making the HON longer and more complex. The EPA recognizes that

some confusion may result from calling these devices ``boilers'' in the

HON, when they are known as ``industrial furnaces'' under RCRA.

However, this potential is small, and can be managed through

appropriate definitions.

The EPA considered several alternatives to using the definition of

``boilers'' to address industrial furnaces. All these alternatives

presented more serious difficulties than using the term ``boilers.''

For example, except for one instance in the wastewater provisions of

subpart G (an error which is being corrected by these amendments), the

HON does not use the term ``industrial furnace.'' In order to use that

term consistently, it would have to be added to multiple locations

throughout three subparts, and a new definition would probably be

needed. In contrast, the provisions for ``boilers'' are already

appropriate for industrial furnaces. Thus, the desired result can be

accomplished with less revision of the regulatory text.

The EPA also considered the option of calling these devices

``incinerators'', because many industrial furnaces more closely

resemble incinerators than boilers, i.e., they combust organic HAP

without producing steam. However, in this case there would still be

confusion because RCRA regulations differentiate between incinerators

and industrial furnaces. Additionally, incinerators and industrial

furnaces are regulated under different subparts of the RCRA

regulations. This would make the HON's cross-references to RCRA

regulations extremely complex, if the EPA attempted to address

industrial furnaces in the existing HON provisions for incinerators. In

contrast, boilers and industrial furnaces are regulated in the same

subpart of the RCRA regulations (40 CFR part 266, subpart H), so that

the existing cross-references may be used without revision. After

balancing all these factors, the EPA concluded the best approach would

be to include industrial furnaces within the HON definition of

``boiler.''

E. Monitoring/Recordkeeping/Reporting Provisions

1. Correction to Monitoring Requirements for Acid Gas Scrubbers

The EPA is also proposing corrections to the requirements for

continuous monitoring of gas flow entering an acid gas scrubber. In

cases where a scrubber is used after a combustion device for

halogenated streams, subpart G currently requires that a flow meter

with a continuous recorder be installed at the scrubber inlet to

measure gas flow. The EPA has received new information that

demonstrates that continuous monitoring of this acid gas stream is

impractical due to the harsh conditions at the scrubber inlet. A

continuous monitoring device would be expected to have a very short

service life due to the combination of high temperature and

corrosivity/low pH. Thus, it would be extremely costly to comply with

the current requirement for continuous monitoring of gas stream flow.

Therefore, the EPA is proposing to revise Sec. 63.114(a)(4)(ii) and

Sec. 63.127(a)(4)(ii) to allow three different options for determining

gas flow. Each of these options would provide sufficient data to

determine a liquid/gas (L/G) ratio for use in monitoring operation of

the acid gas scrubber.

The first option being proposed would allow owners or operators to

determine gas flow to the scrubber by using the design blower capacity,

with appropriate adjustments for pressure drop. This would provide a

``worst case'' gas flow. If the required compliance demonstration

showed that a scrubber could meet the emission reduction requirements

of subpart G for hydrogen halides and halogens during these worst-case

flow conditions, the EPA anticipates that compliance would also be

achieved during conditions of lower gas flow.

In the second proposed option, the EPA recognizes that some post-

combustion scrubbers, regulated under RCRA, are already required to

determine a L/G ratio to demonstrate compliance with emission reduction

requirements. The EPA is proposing that methods of determining gas flow

which have been utilized to comply with pre-existing RCRA regulations

should also be acceptable for purposes of subpart G. This proposed

option also provides that a determination made before the compliance

date for this rule may be used in the compliance demonstration if it is

still representative.

Finally, the EPA is proposing that owners or operators may develop

a gas flow determination plan. The plan would specify a reliable method

for determining gas stream flow, to provide a representative or at

least a worst-case flow rate during representative operating

conditions. Recordkeeping requirements would apply. The EPA believes

that this performance-oriented option is necessary due to the wide

variety of technologies and process configurations in existence. For

example, many SOCMI combustion units utilize multiple scrubbers in

series. This may require a different approach to determining gas flow,

than when a single scrubber is used.

2. Implementation Plans

With today's proposed amendments, EPA is proposing to remove the

requirement for submittal of implementation plans for existing sources'

emission points that are not included in an emissions average. Under

the April 22, 1994, rule, owners or operators, who have not yet

submitted an operating permit application with the information

specified in Sec. 63.152(e), were required

[[Page 43706]]

to submit by April 22, 1996, an implementation plan for points not

included in an emissions average. On February 29, 1996 (61 FR 7716),

this date was revised to December 31, 1996, to allow time for owners or

operators of sources to consider recent changes to the rule and to

allow for expected further revisions to the rule.

This change is being proposed because it no longer appears that

this report would serve a useful function, and the implementation plan

for points not included in an emission average represents a duplicative

and unnecessary burden with the Notification of Compliance Status. By

December 31, 1996, many, if not most, sources will have already

submitted the information covered by the implementation plan in permit

applications. Any remaining sources will be covered by subsequent

permit applications. Thus, the implementation plan requirement is

redundant and, therefore, unnecessary. Furthermore, the implementation

plan for points not included in an emission average would not have been

subject to EPA approval. Finally, eliminating the implementation plan

requirement would make the HON consistent with later MACT standards for

the same types of emission points which have not required this report.

It should not be inferred from this proposal to eliminate

implementation plans for points not included in an emissions average

that the requirement for an implementation plan for points included in

an emission average will be eliminated. This report is needed to ensure

that a proposed average will meet all the criteria in the rule and that

it will result in credits exceeding the debits. Because of the

complexities and site-specific nature of emissions averaging, this

report will remain subject to EPA approval.

3. Startup/Shutdown/Malfunction Plans

The EPA is proposing to revise several sections in the rule to

clarify the requirements for start-up/shutdown/malfunction periods.

These clarifications include revisions to the definitions of ``start-

up'' and ``shutdown'' and revisions to the monitoring and recordkeeping

requirements in Sec. 63.152 of subpart G. These changes are being

proposed to address several oversights in the original drafting and to

make the requirements for start-ups/shutdowns/malfunctions more

explicit to avoid potential misunderstanding of the requirements.

Revisions are being proposed to the definitions for the terms

``start-up'' and ``shutdown'' to make these terms more consistent and

to extend these terms to include part of a cmpu (such as a wastewater

tank) as well as the entire unit. The present definitions also do not

apply to control equipment used to comply with the rule or to waste

management units. Thus, if there were a start-up/shutdown/malfunction

of an individual item of equipment or an item of equipment not

presently included in the definition, it would not be permissible for

the owner or operator to follow the start-up/shutdown/malfunction plan

because it would not apply. Since it was intended that the start-up/

shutdown/malfunction plan would be followed in such situations, the

definitions are being revised to reflect this intent. The definition of

``start-up'' is also being revised to include activities associated

with initial start-up, testing of equipment, and transitional

conditions due to changes in product for flexible operation units. The

current definition for ``start-up'' erroneously excludes these

activities which should be addressed under the start-up/shutdown/

malfunction plan. The proposed revisions correct these drafting errors.

As part of the correction to the definitions for ``start-up'' and

``shutdown,'' EPA is also proposing to add two paragraphs to

Sec. 63.102(a) to clarify operational requirements during periods of

start-up/shutdown/malfunction. These provisions are necessary to avoid

misuse of the revised definition of the term ``shutdown.''

Revisions are being proposed for several paragraphs in Sec. 63.152

to clarify that monitoring is not required during periods when the

source is not operating and that the start-up/shutdown/malfunction plan

details the monitoring requirements during periods when the plan is

applicable. Currently, the rule does not explicitly address monitoring

requirements during periods when the source is not operating. Because

of concerns that this absence of direction could be interpreted as

requiring monitoring after shutdown of a source, clarifying language is

being proposed to remove any potential for misinterpretation. Minor

revisions are proposed to Sec. 63.152, paragraphs (c) and (f) to

clarify that data recorded during periods of start-up/shutdown/

malfunction are not excursions and are not to be included in averages

of monitoring data. These changes are being made to ensure that it is

clear that during periods of start-up/shutdown/malfunction the source

is required to follow the procedures in the start-up/shutdown/

malfunction plan in lieu of requirements that would otherwise apply to

the affected emission points under subpart G.

4. Alternative recordkeeping provisions

Today's proposed changes to the rule include addition of new

provisions to allow use of an alternative recordkeeping system that

records fewer data points during periods of routine compliance provided

the system meets specified criteria and the system is verified annually

to meet the requirements. The proposed provisions would provide an

alternative to the existing provisions in Sec. 63.152(f) for data

compression systems. These new provisions are expected to reduce

recordkeeping burden for some facilities.

The proposed alternative recordkeeping provisions allow an owner or

operator to use an exception-only recording system provided the system

meets specified criteria and the system is demonstrated to operate

properly initially, annually, and on demand. The new provisions require

that the monitoring system be able to: (1) Detect abnormal or

``impossible'' data (e.g., temperature reading of -200 deg.C on a

boiler), (2) detect inappropriate ``flat-line'' data, (3) alarm at a

set-point that is related to a limit on a parameter range, (4) generate

a running daily average that could be used by plant personnel or to

satisfy an inspector that the system is operating and the parameter is

within established limits, and (5) allow a system check on demand

during normal operations to verify that the system is recording data

properly. A description of the monitoring system, and the most recent

superseded description, must be retained. The current description would

be retained at least 5 years and longer, if it has not been superseded.

It must be retained either on-site or by a method that allows access

within two hours after a request. The most recent superseded

description would be retained for at least 5 years from its creation

but could be stored off-site if it is more than six months old. If the

superseded version is already more than 5 years old (at the time it

becomes superseded) it may be discarded immediately. The facility would

select the specific levels for the alarm set points considering the

variability of the process operations and the control device stability

under different operating conditions. It is expected that these alarm

set points would be established at a level such that corrective action

could be taken to prevent occurrence of a parameter excursion. The

alternative provisions allow the owner or operator to retain

[[Page 43707]]

only the daily average value under most circumstances. If no excursions

occur in a period of 6 consecutive months, the owner or operator is not

required to record the daily average, but must record and retain weekly

at least one parameter value during a period of operation other than a

start-up, shutdown, or malfunction. If a non-excused excursion occurs,

the owner or operator must immediately resume retaining the daily

average value for each day. An owner or operator electing to use this

alternative is required to notify EPA in the Notification of Compliance

Status or periodic report with updates whenever there is a change in

the frequency of data retention.

The proposed alternative system in Sec. 63.152(g) differs from the

alternative system for data compression systems provided in

Sec. 63.152(f) and the existing continuous monitoring requirements in

that the Sec. 63.152(g) alternative bases compliance on demonstration

of a system and records for periods of abnormal operation. The EPA

believes that this alternative provides an opportunity to use current

technology to reduce the cost of monitoring and compliance

demonstration. It is also anticipated that facilities electing to use

these provisions will have better emission control than facilities not

using an early warning type system. Because the system has to pass an

initial, annual, and on demand performance demonstration, EPA believes

that there are sufficient safeguards to ensure the system is operated

properly.

5. Miscellaneous Clarifying Edits to Recordkeeping Requirements

The proposed amendments to the rule include several other revisions

to reduce the recordkeeping burden of the rule in addition to those

described above. First, the proposed amendments include an additional

alternative for cmpus that do not use as a reactant, or make as a

product, any of the organic HAP's listed in table 2 of subpart F.

Parallel changes are also being proposed for similar documentation

requirements in subpart I. The new provisions, which would be added to

Sec. 63.103(e) and Sec. 63.192(k), would allow an owner or operator to

document the inapplicability of the rule on the request of an

inspector. This alternative is being provided because it was never

EPA's intent to impose an ongoing recordkeeping requirement on sources

not subject to the rule and because the current provisions can be

interpreted to impose such a requirement.

EPA proposes to revise Sec. 63.103(c) to remove the requirement for

an owner or operator to maintain copies of reports if the report has

been sent to the EPA Regional Office and the State agency. If the EPA

Regional Office has waived the requirement for submittal of reports to

the Region, the owner or operator is not required to maintain copies of

the reports. This revision is being made due to concern that misplacing

a copy of a report would be a violation, even though the report had

been properly submitted. This was not EPA's intent.

It is also proposed to revise Sec. 63.103(c) to reduce the volume

of records that must be stored on-site. Concern has been expressed that

on-site storage is often limited and more costly than off-site storage.

Subpart F currently requires the most recent 2 years' records to be

stored on-site. The proposed revision would specify that at least 6

months' records either be stored on-site or be available within 2 hours

by any means. The remaining 4 and one-half years worth of records may

be retained off-site. A definition of ``on-site'' would be added to

clarify that the records may be kept anywhere at the source, such as a

central filing area. These changes are being made to clarify what the

necessary records are and to specify the performance objective, and not

the method, that must be used to comply with the requirement.

The proposed amendments to subpart F include revisions to

Sec. 63.103(c)(2) documentation requirements for periods of start-up/

shutdown/malfunction. The proposed changes would make these provisions

consistent with the requirements in subpart A (General Provisions) to

document and report periods in which excess emissions occur. Another

proposed change to reduce burden and simplify the reporting

requirements is the elimination of the difference in submittal dates

for reports sent by U.S. Mail and by other delivery services. This

proposed revision to Sec. 63.103(d)(1) specifies that reports shall be

submitted on or before the relevant dates and the provisions in

Sec. 63.103(d)(1)(i) and (ii) would be removed from the rule. This

change is being made to eliminate an unnecessary restriction.

The proposed amendments include revisions to table 3 of subpart F

to clarify the applicability of specific sections in subpart A to

subpart H. Table 3 to subpart F currently does not explicitly detail

the applicability of the requirements to subpart H, and there are some

incorrect references to subpart A. The proposed revisions to the table

correct these errors.

6. Miscellaneous Changes to Monitoring Requirements

The EPA is proposing to clarify the instrument installation,

calibration, operational, and maintenance requirements that occur

throughout subpart G for instrumental monitoring of control devices.

The current rule requires the owner or operator to follow the

instrument manufacturer's recommendations for installation,

calibration, and maintenance. The proposed revision would allow the

owner or operator to develop a written procedure that provides adequate

assurance that the equipment would reasonably be expected to monitor

accurately. This revision is being proposed because many facilities in

the SOCMI industry do not purchase off-the-shelf monitoring systems.

Instead, it is common in this industry to develop monitoring systems

from equipment purchased from several suppliers. Thus, it is likely

that there are no manufacturer's instructions for the particular system

installed. Even in cases where a monitoring system is purchased and

used without substantial modification, the environment in which the

instrument is operating may differ from the manufacturer's expected

conditions sufficiently to make the manufacturer's recommendations

meaningless or inappropriate. The proposed amendment would provide the

necessary flexibility while preserving the intent to ensure accurate

data.

Today's proposed amendments also clarify that the requirement to

monitor regeneration stream ``mass flow'' in carbon adsorbers means

volumetric flow of the regeneration stream. This requirement occurs in

several places in the rule (e.g., 40 CFR Sec. 63.114(b)(3)). The

language in these sections is being revised because there is concern

that the word ``mass'' might be misinterpreted as prohibiting existing

types of monitoring that meet the intent of the requirement. The

purpose of the requirement is simply to monitor to show that the carbon

beds are being regenerated and maintained properly. While there are

systems that provide a measure of the mass by monitoring several

parameters and converting the results to mass, these systems as well as

volumetric flow metering systems all start with measurements of volume.

The proposed amendments replace all existing references to ``mass

flow'' with ``mass or volumetric flow.''

The EPA is also proposing to amend subpart G by revising the

definition of ``flow indicator'' and by revising the regulatory

language specifying the

[[Page 43708]]

requirement for monitoring by-pass lines (e.g. Sec. 63.114(d)(1)) to be

consistent with the provisions and definitions in subpart H. The

proposed definition includes reference to devices that detect the

potential for diversion of a stream by methods other than ``flow''

monitoring and the by-pass monitoring requirements no longer refer

exclusively to the presence of flow or imply that flow has to be

measured. The revised definitions and rule provisions allow use of any

means that will provide an indication of diversion of the stream from

the control device.

7. Manual Recordkeeping Provisions

The EPA is requesting comment on whether the provisions in

Sec. 63.151(g)(3) for manual recordkeeping systems should be revised to

allow requests for approval of monitoring on a less frequent basis than

once every 15 minutes. The EPA has received requests that this

provision allow monitoring once per 8-hour shift (or less frequently)

if the owner or operator can demonstrate that operating parameters for

the control device do not vary significantly over time. Examples of

systems that the requestor believed should require only limited

monitoring include condensers and acid gas scrubbers that vary slowly

over time. The requestor believed that the present rule requirements

impose a significant burden on facilities without automated recording

systems since plant personnel would have to expend considerable time

recording data.

In previous decisions on requests for alternative monitoring

systems for standards established under 40 CFR parts 60 and 61, EPA has

sometimes allowed less frequent monitoring based on consideration of

the level of the actual emissions in relation to the standard and the

control technology stability. These reviews have considered the process

operating characteristics and the nature of the types of control

problems that could occur. In situations where it is extremely unlikely

that a significant emission event could go undetected, less frequent

monitoring has been allowed. If EPA were to revise subpart G to allow

less frequent monitoring for facilities with manual recordkeeping

systems, it is likely that the provisions would require that the

emission point be operated at a level substantially below the level of

the standard (e.g., a TRE greater than 4, a 99 percent reduction when

the rule requires a 95 percent reduction, or a substantially lower

emission rate than allowed), and its availability would be limited to

certain control technologies. Monitoring less frequently than once per

hour might be appropriate for carbon adsorbers and some absorbers but

less frequent monitoring would not be appropriate for equipment such as

condensers. Adsorbers tend to exhibit failure over a relatively long

period of time while condensers can fail quickly if a compressor fails

or if flow rates through the condenser are increased significantly.

Monitoring a condenser once a day could permit a significant undetected

emissions episode. The EPA is not currently proposing a reduced

frequency of monitoring. However, the EPA requests comment on the need

for a reduced frequency as well as the appropriate criteria for

allowing the use of less frequent monitoring (such as once per shift)

and the basis for the recommended criteria.

F. Overlap with Other Regulations

1. Benzene Waste NESHAP

The April 22, 1994 rule requires that sources with wastewater

streams subject to control requirements in the HON and Benzene Waste

NESHAP (40 CFR part 61, subpart FF) comply with both rules. Since April

1994, members of the regulated community have objected that this

requirement unnecessarily increases the cost of demonstrating

compliance and complicates management of environmental programs at a

facility without providing a corresponding environmental benefit. To

address these concerns, EPA is proposing to add a compliance option to

Sec. 63.110(e)(1) that would allow some consolidation of the

inspection, monitoring, recordkeeping, and reporting requirements of

these two NESHAP.

The proposed amendments would allow an owner or operator to use the

wastewater provisions of this rule as compliance with the provisions of

the Benzene Waste NESHAP provided two conditions are met. First, the

owner or operator must comply with the wastewater provisions of subpart

G. Second, for any Group 2 wastewater or organic stream whose benzene

emissions are subject to control under the provisions of the Benzene

Waste NESHAP, the owner or operator will comply with the requirements

for Group 1 wastewater streams in subpart G for that stream. This

proposed additional compliance option is designed to maintain the

applicability and stringency of existing control requirements for the

Benzene Waste NESHAP while providing an opportunity to reduce the

complexity of the compliance demonstration by reducing the number of

separate rules that apply to the equipment. The number of streams that

are subject to control under the Benzene Waste NESHAP would not be

changed by electing to use this option. The EPA wishes to emphasize

that this additional compliance option would not supersede any

existing, still-effective agreements to take mitigating actions that

were granted in exchange for additional compliance time with the

Benzene Waste NESHAP. These agreements would not be altered by this

proposed amendment to this rule.

2. Resource Conservation and Recovery Act (RCRA)

In developing the April 1994 rule, EPA attempted to address the

problem of overlapping requirements by specifying which provisions

apply for each of the known cases of overlapping rules. These

instructions on overlapping requirements were provided in Sec. 63.110

of subpart G and in Sec. 63.160 of subpart H. Since issuance of the

rule, EPA has learned that there is another broad category of

overlapping RCRA requirements that was not addressed in the April 1994

rule. In today's amendments, EPA is proposing provisions to allow use

of certain RCRA-required monitoring to satisfy corresponding

requirements in subpart G and H. These proposed provisions would be

added to these subparts as Sec. 63.110(h) and Sec. 63.172(n).

The April 1994 rule addressed the known overlaps of control

requirements between the RCRA rules in 40 CFR parts 260 through 272 and

the wastewater control requirements of this rule. Due to an oversight,

the April 1994 rule did not specify the applicable requirements in

cases where the same control device (e.g., incinerator or adsorber) is

subject to a RCRA rule and would be used to comply with requirements

for non-wastewater provisions of this rule. Presently, the April 1994

rule would require the owner or operator to comply with the applicable

monitoring, recordkeeping, and reporting provisions of each rule.

Compliance with both rules' monitoring, recordkeeping, and reporting

requirements would significantly increase the cost of compliance

demonstrations without providing a corresponding environmental benefit.

To reduce this unnecessary burden, the EPA is proposing to allow an

owner or operator to elect to use the monitoring, recordkeeping, and

reporting requirements in 40 CFR parts 260 through 272 for this rule.

The EPA considers this proposed consolidation of overlapping

monitoring, recordkeeping, and reporting requirements to be appropriate

[[Page 43709]]

because the RCRA air rules and the HON have the same objective and

monitor similar operational characteristics of control devices. In

general, the RCRA requirements tend to require more frequent monitoring

and retention of more detailed information. Therefore, it is possible

to use the RCRA data and reports to demonstrate compliance with the

provisions of this rule.

Today's amendments also propose to accept demonstrations of

compliance with RCRA requirements as demonstration of compliance with

the process vent, transfer operations, storage vessels, and equipment

leak provisions of the HON. The wastewater provisions in subpart G

presently exempt hazardous waste incinerators permitted under 40 CFR

part 270 and boilers and industrial furnaces permitted under 40 CFR

part 266 from performance test requirements of Sec. 63.139. These RCRA

air rules were judged to be at least as stringent in controlling air

emissions as this rule so that a second compliance demonstration was

not necessary. This judgment is applicable to the control requirements

for the non-wastewater provisions of this rule. Therefore, it is

proposed to add these rules to the list of controls exempted from

performance tests or other compliance demonstration requirements in

Sec. 63.116(b), Sec. 63.128(c), and Sec. 63.139(d)(4) and to add

provisions to Sec. 63.120(d) to list controls exempt from compliance

demonstration requirements.

G. Proposed Changes to Subparts H and I

In addition to the applicable changes discussed in earlier sections

of this preamble, the proposed changes to subpart H consist of: (1)

clarification of the terms ``repaired'' and ``first attempt at repair''

and clarification of the followup monitoring requirements for

connectors and valves; (2) correction of Sec. 63.180(b)(4) to allow use

of calibration gases other than methane; and (3) miscellaneous

corrections and clarifications to the wording of a few paragraphs.

1. Clarification of Definitions

The EPA is proposing to revise the definitions of the terms

``repaired'' and ``first attempt at repair.'' These proposed changes

are intended to eliminate the confusion that presently exists regarding

what monitoring is required after leaks are repaired. The definition of

``repaired'' presently states that the equipment is adjusted or

otherwise altered to eliminate a leak. The EPA has received inquiries

whether this definition implies that there must be proof by monitoring

data that the leak was repaired. These questions have been raised

because other sections of subpart H impose such a requirement. Because

of inquiries such as these, EPA reviewed subpart H and determined that

the confusion regarding the requirement was due in part to the lack of

specificity in the definition of the terms ``repaired'' and ``first

attempt at repair.'' The proposed amendments to subpart H would revise

these definitions to explicitly include reference to verification

monitoring according to the procedures in Sec. 63.180(b) and (c), as

appropriate. From this review, it was also determined that some of the

confusion was arising from lack of specific statement in applicable

sections of the rule that verification monitoring was required. The

proposed changes to subpart H would correct this problem.

2. Followup Monitoring

The EPA has received inquiries regarding the requirements for

monitoring within 3 months after repair of a leaking valve and the

relationship between this monitoring and the periodic monitoring

required by the standard. The proposed amendments would add provisions

to Sec. 63.168(f)(3) to clarify that (1) monitoring is conducted

according to the procedures specified in Sec. 63.180 (b) and (c) and

(2) the periodic monitoring may be used to satisfy this requirement if

the timing of this monitoring coincides with the timing specified for

the followup monitoring. The new provisions that would be added to

Sec. 63.168(f)(3) would also specify how to consider the results of

this monitoring in the calculation of percent leaking valves should a

leak be detected. These proposed changes would revise the rule to

correct oversights in the original drafting and to ensure that the rule

reflects EPA's intent.

The EPA has also received inquiries regarding whether subpart H

requires followup monitoring of connectors found to be leaking. These

questions have arisen due to a lack of clarity in Sec. 63.174 (c)(1)(i)

and (c)(1)(ii) that these provisions apply to connectors that have been

opened. The proposed change to the rule would clarify this point.

3. Calibration Gases Other Than Methane

The EPA is proposing to revise Sec. 63.180(b)(4) to allow use of

calibration gases other than methane. Since April 1994, some industry

representatives and equipment vendors have expressed concern to EPA

that present restriction to use methane as the calibration gas

precludes use of the procedures in Method 21 which permit calibration

with another reference compound. As discussed in the April 22, 1994

Federal Register, EPA intended to allow the use of reference compounds

other than methane in the calibration gases. However, due to a drafting

error Sec. 63.180(b)(4)(ii) was not modified to allow this flexibility.

The proposed amendments to this section of the rule would revise this

paragraph to allow the use of other compounds when the instrument does

not respond to methane or does not meet the performance specifications

of Sec. 63.180(b)(2)(i). The EPA considered whether this revision

should include a requirement to adjust the instrument readings to a

methane base in order to have the readings on the same basis as

instruments calibrated using methane. The proposed provisions do not

require such an adjustment for the same reasons given in the April 22,

1994 notice for removal of the 1992 proposed rule's requirement of

adjustment for response factors (59 FR 19447-19448).

Changes to Subpart I

The proposed changes to subpart I consist of corrections of several

cross-referencing errors and revisions to the general recordkeeping and

reporting requirements in Sec. 63.190(f). The proposed amendments to

Sec. 63.190(f) are the same as the revisions to Sec. 63.103(c)

discussed in section III. E. 5 of this preamble.

IV. Basis for Proposed Changes to Wastewater Provisions

A. General Comments on Changes to Wastewater Provisions

Today the Agency is proposing amendments to the wastewater

provisions in subpart G that are designed to clarify provisions of the

rule that have been misunderstood by some in the SOCMI industry. If

promulgated, the proposed clarifying amendments would not change the

basic control requirements, predicted emission reductions, or cost of

the rule. A summary of the amendments is provided in the following

paragraphs.

Four sections have been rewritten entirely in today's amendments to

improve clarity and to incorporate the new ``point of determination''

concept discussed in section IV.D of this preamble. The four sections

address: criteria for determining the Group 1 and Group 2 wastewater

streams (Sec. 63.132); performance standards for process wastewater

(Sec. 63.138); procedures for determining Group 1 and Group 2

wastewater streams (Sec. 63.144); and procedures for demonstrating

[[Page 43710]]

compliance (Sec. 63.145). Also, requirements allowing the use of

floating flexible membrane covers on surface impoundments have been

added to Sec. 63.134, and a section addressing in-process equipment

(Sec. 63.149) has been added.

Minor changes are proposed to the sections governing waste

management units, control devices, delay of repair of waste management

units, inspections and monitoring, recordkeeping, and reporting.

As a result, today's wastewater provisions are being proposed in

Secs. 63.132 through 63.147, in Sec. 63.149, in tables 8 through 20, in

tables 34 through 37, and in figure 1 of appendix A to subpart G.

Deletions include Sec. 63.131 (reserved since information became

unnecessary with amendments) and the figures and tables 14a, 14b, and

16 to subpart G. The proposed amendments would add a new table 15,

which replaces tables 15a and 15b of the April 1994 rule, and tables 35

through 37 and figure 1, which provides a key to the terms in the

wastewater equations. Fraction measured values (Fm) in Table 34 were

corrected for four compounds: trichlorophenol, Fm=0.11; chlorobenzene,

Fm=1.00; isophorone, Fm=0.51; and 1,1,2-trichloroethane, Fm=1.00. In

addition, tables 11, 12, 17, and 18 were revised.

B. Wastewater Definitions

1. Summary of Significant Changes

Significant changes proposed are: revisions to the ``wastewater''

definition; replacement of the ``point of generation'' (POG) definition

with ``point of determination'' (POD) definition; addition of

``closed'' and ``open biological treatment process'' definitions;

addition of the ``enhanced biological treatment system'' definition;

revisions to the ``individual drain system'' definition; and deletion

of definitions for ``total volatile organic hazardous air pollutant

(VOHAP)'', ``volatile organic concentration'', and ``VOHAP

concentration.''

Changes to some of the definitions, especially ``wastewater'',

``recovery device'', and ``point of generation'', were necessary due to

circularity and a lack of specificity in the definitions. The

definitions were revised to clarify EPA's intent concerning which

organic HAP-containing waters are in-process fluids regulated by the

provisions in Sec. 63.149 and which are wastewater and regulated by the

provisions in Sec. 63.132 through Sec. 63.147.

2. Revised Wastewater Definition

The most significant change proposed today to the ``wastewater''

definition is the addition of the concept of ``discard.'' The discard

concept is fundamental in distinguishing which fluids exiting the cmpu

are subject to the HON wastewater provisions in Secs. 63.132 through

63.147. Together with the point of determination and in-process

equipment concepts, the revised definition of wastewater makes

decision-making for facilities and regulatory authorities more

straightforward, and the rule more easily implemented. Since fluids in

the in-process equipment are also controlled by the HON, emission

reductions will not be affected by this proposed change.

3. Replaced Point of Generation With Point of Determination

Today's proposal would change the definition for ``point of

generation'' in two ways--one way a conceptual change and the other a

change in terminology. ``Point of generation'' was changed to ``point

of determination'' to distinguish it from the term, ``point of

generation'' as used in the Benzene Waste NESHAP. ``Point of

generation'' was defined in the April 1994 rule as ``the location where

process wastewater exits the process unit equipment,'' (i.e. exits the

last recovery device). In today's proposal, it has been replaced by

``point of determination'', which is defined as ``each point where the

process wastewater exits the chemical manufacturing process unit.'' The

need for and significance of this change is discussed in more detail in

section IV.D. of this preamble.

4. Recovery Device

The proposed amendments include a revised definition of ``recovery

device.'' The proposed definition of ``recovery device'' differs from

the existing definition in order to reflect the revised approach to the

definition of ``wastewater'' and to reflect the fact that deviations

from normal operations do occur.

Under the revised approach for defining wastewater, a stream does

not become wastewater until it exits the last recovery device. As a

recovery device had been defined as an item of equipment used to

recover chemicals for fuel value, use, reuse, or ``sale'', it would

seem impossible--by definition--to sell a wastewater stream or residual

extracted from a wastewater stream. In developing the revised approach

for wastewater, it became apparent that using the term ``sale'' without

any qualification in the definition of ``recovery device'' left a

potential loophole. A bad actor could ``sell'' a Group 1 stream to an

affiliate for a negligible amount, claim that it was a sale so that the

stream had not yet exited the last recovery device (so it was not

wastewater), and the affiliate could simply dispose of the stream or

residual without treating it in accordance with the HON provisions (and

incurring the costs of such treatment). The additional language is

intended to remove the possibility of such sham transactions by

limiting the concept of sales to sales for the same general purposes

for which chemicals may be recovered and utilized within the HON

facility (i.e.,use, reuse, or burning as fuel). The EPA believes that

such language is broad enough to encompass any sale that is not a sham

since ``use'' and ``reuse'' are very general concepts. The definition

also differs from the existing definition in that the word ``normally''

now modifies the phrase ``used for the purpose of recovering ....''

This change was made to recognize that occasional exceptions to normal

usage can and will arise.

5. Added Definitions for Closed Biological Treatment Process, Open

Biological Treatment Process, and Enhanced Biological Unit

Definitions for closed biological treatment process, open

biological treatment process, and enhanced biological treatment system

would be added to the definitions in subpart G. The new definitions are

necessary to make distinctions among biological treatment processes

which allow the incorporation of more flexible and less burdensome

compliance demonstrations for some facilities. This is discussed in

more detail in the discussion of changes to Sec. 63.145 in section

IV.F. of this preamble.

6. Modified Individual Drain System Definition

The definition for individual drain system would be modified to

clarify three key concepts and incorporate minor wording changes. The

definition in today's proposal would clarify that only stationary

systems are included in the definition; that individual drain systems

are used to convey residuals as well as wastewater streams; and that

the individual drain system does not include in-process equipment as

described in Sec. 63.149.

[[Page 43711]]

7. Deletion of Total VOHAP, VO Concentration, and VOHAP Concentration

Definitions

The EPA proposes to delete the definitions for ``total VOHAP'',

``VO concentration'', and ``VOHAP concentration.'' As discussed in

section IV.F. of this preamble, these terms would no longer be used in

the rule; therefore, the definitions would not be needed.

C. Changes to Sec. 63.132

In the April 1994 rule and in today's proposed changes to the rule,

Sec. 63.132 provides the instructions on how to determine if a process

wastewater stream requires control and the general outline of

requirements for process wastewater streams. The general approach for

determining which wastewater streams are Group 1 or Group 2 would not

change. Determination of whether a wastewater stream is Group 1 or

Group 2 would still be based on the same concentration and flow rate

criteria as the current rule. Control requirements for Group 1

wastewater streams still require that HAP emissions be controlled until

the HAPs are either removed from the wastewater or destroyed. Today's

proposal reorganizes Sec. 63.132 to eliminate redundant sections,

clarify requirements, and change the order of the provisions into a

more reader friendly format. Other proposed changes include use of the

point of determination concept instead of the point of generation

concept (discussed in IV.D. of this preamble) and the addition of

language prohibiting the discard of certain organic material into water

or wastewater.

Language prohibiting the discard of certain organic material into

water or wastewater would be added as Sec. 63.132(f). Specifically,

liquid or solid organic materials containing greater than 10,000 parts

per million of Table 9 compounds may not be discarded into water or

wastewater unless the receiving stream is managed and treated as a

Group 1 wastewater stream. The prohibition would exclude equipment

leaks; activities included in the start-up/shutdown/malfunction plan,

including maintenance wastewater; spills; and samples. This paragraph

would be added to eliminate the potential for dumping of high

concentration organic streams, such as off-specification product, into

the sewer. The EPA seeks comment on the appropriate size of a sample.

D. Basis of Determining Group Status of a Wastewater Stream: Change

From Point of Generation to Point of Determination

The EPA is proposing to revise the rule to base the determination

of applicability of control requirements to a wastewater stream on its

characteristics at the point where the wastewater stream exits the last

recovery device instead of at the point of generation (POG). The new

location for determining the characteristics of a wastewater stream is

being called the point of determination (POD) to distinguish it from

the POG concept used in other air rules for waste and wastewater such

as the Benzene Waste NESHAP. As discussed earlier in the OVERVIEW OF

CHANGES TO THE RULE, this proposed revision is one of several changes

being made to address problems with drafting clarity and structure of

the wastewater provisions. The proposed concept of POD along with the

revised definitions for key wastewater terms and the provisions for in-

process equipment subject to the provisions of Sec. 63.149 is

consistent with the emission and cost estimates used to support the

April 1994 rule.

1. Point of Generation Concept in April 1994 Rule

In the April 1994 rule, the term POG is defined as the point where

the process wastewater exits the process unit equipment. The EPA's

intent with the POG approach was to identify wastewater streams for

control prior to opportunities for losses due to emissions to the

atmosphere, prior to dilution with other wastewater streams, and prior

to partial treatment of the wastewater stream. If dilution or partial

treatment prior to a control determination were allowed, some

wastewater streams that would have required control based on the

concentration criteria would not meet the requirement of the rule for

control and would therefore not be treated.

A fundamental premise of the POG concept is that a clear

distinction can be made between process equipment and waste management

units. In development of the April 1994 rule, EPA emphasized that the

distinction was based on whether the material and the unit in which it

is managed is an integral part of the production process. The EPA has

learned since 1994 that industry has numerous interpretations of the

concept of ``integral to the process'' and hence the POG concept.

Interpretations vary because evaluation of what is integral to the

process takes into consideration economic and process design factors as

well as knowledge of the process and the industry. Because processes

and configurations of equipment in facilities subject to this rule vary

widely, it is difficult to develop a set of criteria that can be used

to make clear distinctions between process and waste management

equipment. The combination of this problem with the ambiguities and the

lack of specificity in the other key wastewater definitions (e.g.,

wastewater) has resulted in a rule that may be misinterpreted. It is

important that the rule be clear and unambiguous so that all parties

interpret its requirements consistently.

Because of issues raised since promulgation of the April 1994 rule

concerning EPA's intent and the difficulty of making the POG

determination, the EPA has reevaluated the POG concept. As part of this

reevaluation, EPA reviewed the data that were used to develop the

emission and cost estimates for the April 1994 rule. It was determined

from this review that the industry responses in 1990 to the section 114

wastewater questionnaires did not reflect a consistent understanding of

what EPA considered to be wastewater and what EPA meant by the concept

of POG. In many cases, the respondents provided information for a

location that was after the point that EPA considered to be the POG. In

a few cases, it was not possible to determine from the process

description and the description of wastewater streams whether the

information was or was not after the POG. Thus, because of the lack of

consistency in the responses, it is not possible to be certain that the

emission and cost analyses used in development of the April 1994 rule

reflected the POG concept in the rule language. Moreover, it is now

apparent that the POG approach is inherently foreign to the way

facility operators view their processes and it is unlikely that this

concept would be generally accepted and understood by the regulated

community. Because of these practical problems, the EPA concluded that

it was appropriate to develop a new approach for the initial point of

evaluation of a wastewater stream. The new approach that would replace

the POG is called the point of determination (POD).

2. Point of Determination Concept in Today's Proposal

The EPA's intent in developing the POD approach is to have a

decision criterion that is replicable and unequivocally specifies the

location for evaluation of a wastewater stream for

[[Page 43712]]

the purposes of control. The POD therefore encompasses each point where

process wastewater exits the last recovery device. This proposed

definition of POD would allow a facility to recover chemicals for fuel

value, use, reuse or for sale for fuel value, use, or reuse. As with

the POG, under the POD approach owners/operators would not be allowed

to mix streams together for the purpose of escaping compliance by the

diluting of wastewater streams to a level below the 1000 ppmw at 10 L/

min or greater flowrate or the 10,000 ppmw at any flowrate level. Under

the POD approach, process units conveying process fluids in the

chemical manufacturing process unit are subject to the requirements

established in Table 35. Table 35 is consistent with the suppression

requirement for a wastewater stream requiring control. Again, the EPA's

intent is to allow process fluids that have recovery potential to be

sent to recovery devices; however, these fluids are required to be

managed so as to minimize the potential for losses due to emissions to

the atmosphere. In addition, making the POD the location after the last

recovery unit would eliminate the need for the recycle option allowed

under the current wastewater provisions.

The EPA believes the POD approach would allow more flexibility than

currently provided in the rule with regard to materials recovery while

eliminating confusion over the initial point of evaluation for a

wastewater stream for the purposes of control and, at the same time,

maintain the suppression requirements for more concentrated streams.

The POD approach would also make the wastewater provisions consistent

with the data collected for development of the rule and with the other

provisions in the rule concerning definition of process. There are no

expected changes in emission reductions or costs associated with this

revision to the rule.

The EPA considers the proposed POD approach to provide a workable

alternative to the POG approach because the HON addresses the other

emission points in the cmpu. The EPA does not believe that the POD

approach would be appropriate for other rules that are not as

comprehensive in the coverage of emission points. The POD concept would

not be appropriate in cases where it is known that the other emission

points would not be subject to any control requirements.

E. Changes to Waste Management Unit Provisions

1. Clarifications to Process Wastewater Provisions

The proposed clarifications to the text concern the mixing of

wastewater in tanks, methods to insure a water seal is maintained, use

of a flexible shield restricting wind motion across the space between

the discharging pipe and the receiving drain, and venting from junction

boxes. Text was added to explain that alternative methods (other than

the example given in the rule) could be used to demonstrate that water

seals are maintained properly. Clarification was added to the

requirements concerning the flexible shield to describe more fully

where the shield should be located. The proposed clarification for the

venting of junction boxes was written to explain the difference between

venting to the atmosphere of junction boxes with gravity wastewater

flow and venting to the atmosphere of junction boxes with wastewater

pumps. Under today's proposed clarification to the provisions, water

sealed junction boxes with gravity flow or systems that operate with

only slight fluctuations in the liquid level are allowed to vent to the

atmosphere through a specified size of vent pipe. Junction boxes with

pumps that turn on and off, allowing the junction box to alternately

empty and fill, are not allowed to vent to the atmosphere due to the

vapor headspace turnover that occurs. Clarifications were made to the

process wastewater provisions for wastewater tanks to express more

fully the EPA's intent to suppress emissions from these systems.

2. Floating Membrane Covers

Since April 1994 the EPA has received inquires as to the reason

floating membrane covers were not allowed under the wastewater

provisions of the HON. The EPA has allowed the use of floating membrane

covers in other rules. The EPA considered this inquiry and decided that

floating membrane covers would be acceptable for suppressing emissions

from surface impoundments. Provisions would be added to the surface

impoundment requirements derived from the standards in Subpart QQ of 40

CFR part 63 for floating membrane covers. The provisions provide the

requirements for the material used for construction of the floating

membrane cover and for the installation of the cover.

3. Individual Drain System Suppression Requirements

Since promulgation of the April 1994 rule, industry has raised

concerns that the individual drain system suppression requirements

would lead to vapor lock in wastewater collection systems. A vapor lock

occurs in a wastewater system when the wastewater attempts to flow into

or out of an area that is sealed and the pressure in the system cannot

equalize, thereby restricting the flow of the wastewater. The EPA's

intent is to suppress emissions from the collection system and not to

seal the system such that gravity flow systems will be inoperative. The

concern over potential for vapor lock to occur in the individual drain

system would be addressed by removing the requirement to gasket and

latch covers or openings.

In today's proposed amendments, the requirement to seal, gasket, or

latch covers or openings in the individual drain system has been

deleted. The proposed amended text would now read that openings shall

be equipped with a tight fitting solid cover (i.e., no visible gaps,

cracks, or holes). The EPA believes that this requirement would

minimize emissions from openings in wastewater treatment systems and

can be met without creating a vapor lock. The EPA recognizes that

normally there will be a ``visible'' point of juncture between the

cover and the opening, such as where a manhole cover contacts the

manhole frame. The point of juncture generally is a thin, visible line

or crack running around the circumference of the cover. These points of

juncture are not prohibited. The intent is to prohibit gaps or openings

that allow air flow into or out of the collection system. A tightly

fitting solid cover will contact the manhole frame in such a way that

there is a surface (cover) to surface (frame) contact. Certain minor

surface irregularities, such as those associated with a manhole cover

manufactured by casting, are acceptable. A gap between surfaces that

are not intended for sealing is acceptable. For example, a gap between

the outer rim of a manhole cover and the inner rim of the manhole is

acceptable, if the actual sealing surface is between the bottom of the

cover and the top of the manhole. Plugged or capped holes (such as

plugged or capped holes to insert a tool for removal of a cover) are

acceptable. Removal of the plugs or caps is unacceptable, except for

the purpose of conducting those activities for which the rule allows

the cover to be opened and provided the plug or cap is replaced upon

completion of the activity. Warped covers that create a gap for air

passage

[[Page 43713]]

are unacceptable. The EPA believes that relaxing the requirements for

tightly fitting solid covers for individual drain systems will suppress

emissions effectively while also allowing small changes in pressure to

occur in the system and, thereby, eliminating the problem from vapor

lock.

4. Repair Time Allowed for Waste Management Units

The April 1994 rule provides that repair can be delayed for up to

15 or 45 days depending on the type of waste management unit. The EPA

has received requests that 45 days be allowed for repair of all types

of waste management units. This change was requested in order to

simplify implementation of the rule. The EPA evaluated the need for

additional time for repairs for some types of units and determined that

the April 1994 rule provisions did not address situations where parts

could not be obtained in the specified time period. In addition, due to

an oversight, Sec. 63.140 did not allow delay of repair when the waste

management unit was taken out of service. As a result, EPA is proposing

revisions to Sec. 63.140 to allow delay of repair when waste management

units are taken out of service and when additional time is necessary to

obtain spare parts. The proposed revisions do not revise the time

provided for repair of some waste management units from 15 days to 45

days.

F. Changes to Secs. 63.138, 63.144, and 63.145

1. General

Three sections of today's proposed rule, Secs. 63.138, 63.144, and

63.145, were rewritten to improve clarity, to incorporate the point of

determination concept, and to add flexibility in the compliance

demonstration for facilities using biological treatment processes to

achieve the control requirements. Revisions to Sec. 63.144 in the April

1994 rule contained in today's proposal are reorganization for clarity;

addition of methods and an alternative validation procedure; deletion

of the term VOHAP from text; and deletion of simple equations that are

unnecessary. These three sections are discussed together because the

changes made to one of them most likely appears in all three of the

sections. A specific change will be discussed where it first appears or

has the most impact.

2. Changes to Sec. 63.138, Process Wastewater Provisions--Performance

Standards for Treatment Processes Managing Group 1 Wastewater Streams

and/or Residuals Removed From Group 1 Wastewater Streams

Section 63.138 contains provisions for control of Group 1

wastewater streams and residuals from Group 1 wastewater streams. The

most significant changes proposed to Sec. 63.138 are: reorganization

for clarity; deletion of recycling and process unit alternative as

control options; technical corrections to the design steam stripper

specifications and removal of unnecessary specification of steam

quality; clarification of compliance demonstration procedures that may

be used for biological treatment processes; clarification that

treatment in series is allowed; consolidation of provisions for the 1

megagram source-wide exemption into Sec. 63.138; and clarification of

when design evaluations may be used to demonstrate compliance instead

of performance tests.

3. Deletion of Recycling and Process Unit Alternative Options From

Sec. 63.138

The recycling and process unit alternative options (April 1994 rule

paragraphs (b)(1)(i), (c)(1)(i), (d)(2)(ii), and (h)(1), and paragraph

(d), respectively) would be deleted from today's proposed rule. Both

options would become unnecessary under the POD concept proposed to

replace the POG concept. The recycling option allowed an owner or

operator to achieve compliance by recycling a process stream to a

process unit. The recycling provisions in paragraph (f) of the April

1994 rule require that the wastewater or residual not be exposed to the

atmosphere and that waste management units in contact with the

wastewater streams or residual comply with control and inspection and

monitoring requirements. With the proposed point of determination

concept, the recycling option would become redundant because as long as

a fluid stays in the process, it would not be a wastewater subject to

the provisions of Sec. 63.138; instead, it would be subject to the

other provisions of the rule such as storage vessels or Sec. 63.149.

4. Clarification That Treatment in Series Is Allowed

Although it is not stated clearly, the April 1994 rule intended

that more than one treatment process could be used to comply with the

rule. Today's proposed amendments would provide provisions for

treatment in series in Secs. 63.138 and 63.145 and would clarify EPA's

intent. Treatment in series may be used whether or not treatment

processes are connected by hard piping. However, inlet and outlet mass

flow rate determination for compliance demonstration differ, depending

on whether hard piping is used to connect treatment processes and

whether a biological treatment process is part of the series.

5. Consolidation of Provisions for the One Megagram Source-Wide

Exemption Into Sec. 63.138

The provisions for the 1 megagram source-wide option would be

clarified and would be consolidated from Secs. 63.138 and 63.144 in the

April 1994 rule into Sec. 63.138 in today's proposed amendments. This

would make the provisions easier to find and understand for the reader.

6. Alternative Methods to Method 305 used in Sec. 63.144

The EPA is proposing to revise the rule to allow use of alternative

methods for Group 1 or Group 2 determinations for process wastewater

streams in lieu of Method 305. The EPA specifically reviewed Methods

624, 625, 1624, and 1625 and has determined that these methods may be

used with certain additional requirements. These requirements are

specified in Sec. 63.144 (b) of the proposed amendments. Other methods

may be used if they are validated by the Method 301 validation

procedure as discussed below. Because the alternative methods determine

actual concentrations of the organic compounds, the fraction measured

(Fm) values listed in table 34 can be used to adjust the alternative

method measurements to a value representative of what Method 305 would

provide.

Method 305 was developed by EPA to identify streams requiring

control for air emissions; therefore, the method was developed

specifically to retain and measure organic compounds of concern from an

air emission perspective. The Office of Water methods (Methods 624,

625, 1624, and 1625) were developed for different purposes and would

not necessarily address air concerns as does Method 305. The EPA used

four criteria of concern from the air perspective to evaluate the

methods. These four criteria were used to ensure that the alternative

method retained and quantified the organic compounds of concern,

generally referred to as target compounds. The first criterion is that

the method provide a sampling approach that would minimize the loss of

volatiles from the sample while maintaining sample integrity. The

second criterion is that the method

[[Page 43714]]

detect the organic compounds of concern. Third, the method must have

adequate up-front quality assurance and quality control to ensure valid

data. Finally, the alternative method must correct for analyte

preparation and analysis bias. That is, the method adjusts to the

actual concentration of the compound in the sample.

The EPA has compared Methods 624, 625, 1624, and 1625 against the

four criteria listed above and proposes to allow these methods to be

used as alternative methods to Method 305 with some additional

requirements as specified in the proposed revised rule. The EPA is

proposing to allow the use of alternative methods based on the belief

that those parties using this alternative approach are following the

procedures specified in the alternative method and are not using some

modified version of the method. One of the additional requirements

proposed consists of employing a sampling and collection procedure that

minimizes the volatilization of organics. For Method 625, EPA proposes

to require corrections to the compounds for which the analysis is being

conducted. For example, Method 624 requires initial calibration of the

analytical system with the target compounds. The four methods also

specify the list of analytes for which the method can be used.

Additional compounds may be added to the four reviewed methods' analyte

lists by using the Office of Water's Alternative Test Procedure (40 CFR

136.4 and 136.5).

Additional methods other than those previously mentioned also may

be used in lieu of Method 305 if a procedure that minimizes loss of

volatile organic compounds during sampling and collection is employed

and if the method is validated in accordance with sections 5.1 or 5.3,

and the corresponding calculations in sections 6.1 or 6.3, of Method

301. Other EPA methods may be validated using Appendix D of part 63,

``Alternative Validation Procedure for EPA Waste Methods'', provided

that a procedure that minimizes loss of volatile organic compounds

during sampling and collection is also be employed.

7. Deletion of Term ``Volatile Organic Hazardous Air Pollutant''

The EPA found that many in the regulated community found the

terminology ``volatile organic hazardous air pollutant'' (VOHAP)

confusing. The term VOHAP concentration is used in the April 1994 rule

to mean the weight concentration of Table 9 HAP's as determined by

Method 305. This meant when a VOHAP concentration was required, the

results from methods other than Method 305 had to be adjusted by the

compound-specific fraction measured factor (Fm) listed in table 34 of

subpart G to convert actual concentration to Method 305 concentration.

When the April 1994 rule specified a HAP concentration, results from

Method 305 were required to be adjusted by the Fm factors to correct to

the actual concentration while results from other methods would be used

as measured (without Fm adjustment).

With today's proposed amendments, Secs. 63.144 and 63.145 of the

rule would explicitly state when Fm adjustments are appropriate rather

than relying on using the term VOHAP to convey EPA's intent. The

proposed amendments would also remove the term VOHAP. Also under the

proposed amendments, it would be clarified in Sec. 63.144 that annual

average concentration may be expressed either as adjusted by the Fm

factors or with no adjustment.

8. Changes to Sec. 63.145, Process Wastewater--Test Methods and

Procedures to Determine Compliance

Section 63.145 contains the provisions that explain how to

demonstrate compliance with the performance standards in Sec. 63.138.

Several significant changes are proposed to this section. It was

rewritten to improve drafting quality, provide clear statements of

EPA's intent, and correct errors.

9. Reorganization of Sec. 63.145

In today's proposal, Sec. 63.145 is reorganized to clarify

requirements and provide the reader with an understanding of which

paragraphs to use for demonstrating compliance with the compliance

options in Sec. 63.138. Three clarifications are of particular note:

(1) ``Representative operating conditions'' for treatment processes and

control devices are specified in paragraphs (a)(3) and (a)(4) of

Sec. 63.145; (2) conditions under which a performance test or design

evaluation is allowed or under which neither is required are specified

in paragraphs (a)(1) and (a)(2); and, (3) clarification of when Fm

adjustments are allowed are included throughout the section. These

proposed clarifications were in the April 1994 rule but may have been

unclear or placed in other sections, causing readers difficulty in

determining how the sections fit together. The reorganized section

would also make provisions for measuring concentration and flow rate

consistent among paragraphs. EPA believes these changes in rule

language will improve clarity and will improve reader comprehension.

10. Demonstrating Compliance for Biological Treatment Processes

Concerns have been raised that the requirements concerning

demonstrating compliance for biological treatment processes are

confusing and the requirement for site-specific fraction biodegraded

(Fbio) determinations is unnecessarily burdensome. To respond to these

concerns, the EPA reevaluated the performance determination

requirements for biological treatment processes and found that

adjustments could be made to the requirements consistent with the

intent of the rule. The EPA's intent was to allow the use of biological

treatment units that achieved the required mass removal of table 9

compounds through biodegradation and not through emissions to the

atmosphere. Today's proposed amendments would add paragraph (h) which

describes how to determine the site-specific fraction of Table 8 and/or

Table 9 compounds biodegradated (Fbio); clarify that biological

treatment processes must use one of the required mass removal options

to comply with the rule; add flexibility in demonstrating compliance

for biological treatment processes; and add provisions that allow a

subset of the Table 8 or Table 9 compounds to be used to demonstrate

compliance.

Paragraph (h)--how to determine Fbio--is added to make the

provisions easier to find than in the April 1994 rule. In addition,

Sec. 63.145(h), together with appendix C to part 63, provide more

flexibility to the owner or operator to demonstrate compliance for

biological treatment processes. The April 1994 rule required owners and

operators using biological treatment processes to demonstrate

compliance using appendix C to part 63 to determine Fbio. Today's

proposal recognizes that for some biological treatment processes, a

less rigorous determination of Fbio is sufficient to demonstrate

compliance.

When a biological treatment process is used, one of the required

mass removal options, Sec. 63.138(f) or (g), must be chosen as the

compliance option. This was EPA's intent in the April 1994 rule but it

was not stated clearly. The provisions that may be used to demonstrate

compliance depend on whether the biological treatment process is open

or closed. In each case, the proposed rule specifies which compliance

demonstration provisions may be used.

For open biological treatment processes, volatilization is an

important

[[Page 43715]]

concern. Therefore, to demonstrate compliance, the owner or operator

must determine the mass of the Table 8 or Table 9 compounds that is

removed due to biodegradation rather than volatilization. If the open

biological treatment process is an enhanced biological treatment

process, the source would have more flexibility in demonstrating

compliance. To incorporate this flexibility, EPA looked at the Table 9

compounds and determined which are more readily biodegraded and which

are more likely to volatilize before biodegradation can occur in an

enhanced biological treatment process.

11. Performance Requirements for Open Biological Treatment Processes

Because of the reevaluation of the Table 9 compounds, the EPA was

able to separate the compounds on Table 9 into three lists which appear

in table 36. These lists would be used together with other provisions

to specify how the source may demonstrate compliance. Table 36 may only

be used for wastewater streams treated in an enhanced biological

treatment system as defined by the proposed revisions to the rule.

The development of the three lists in table 36 was based on the

individual compound's fraction emitted (Fe), fraction removed in a

steam stripper (Fr), and fraction biodegraded in a biological treatment

unit (Fbio). The values for Fe and Fr that were evaluated were based on

analysis performed for the April 1994 rule. Documentation of this

analysis is available in the docket A-90-23. The Fbio values used to

compile the three lists in table 36 were based on default values for an

enhanced biological treatment unit from the EPA Water8 model. List 1

consists of Table 9 compounds that have Fr values approximately equal

to or less than their Fbio values, and Fe values that are in the middle

to lower volatility range. List 3 consists of Table 9 compounds that

have Fr values of 0.99, Fbio values that are considerably lower than

0.99, and Fe values in the higher volatility range. The Table 9

compounds that were left after this evaluation became List 2.

A performance demonstration would not be required for enhanced

biological treatment systems that receive wastewater streams that

require control and that contain only List 1 compounds on table 36. An

example would be an activated sludge unit that meets the proposed

enhanced biological treatment system definition and treats Group 1

wastewater streams that contain only methanol and nitrobenzene (List 1

compounds). A compliance demonstration would not be required because

the only Table 9 compounds requiring control appear on List 1. For

enhanced biological treatment systems treating wastewater containing

compounds on Lists 1, 2, and/or 3, a performance demonstration is

required.

Today's proposal offers several techniques for demonstrating

compliance for an open biological treatment unit meeting the proposed

definition of an enhanced biological treatment system. The

demonstration is performed by estimating the Fbio for the system using

the first order biodegradation constant (K1) and the forms in appendix

C to part 63. The owner/operator may use any of the procedures

specified in 40 CFR part 63, appendix C to calculate the site-specific

K1s for compounds on Lists 1 and/or 2. The owner/operator may elect not

to calculate site-specific biodegradation rate constants but instead to

calculate Fbio for the List 1 compounds using the defaults for K1s in

table 37 and to follow the procedure explained in Form IIA of appendix

C. For compounds on List 3, the owner/operator is allowed to use any of

the procedures specified in 40 CFR part 63, appendix C, except the

batch tests procedure, to calculate the site-specific K1. Biological

treatment units not meeting the definition of an enhanced biological

treatment system are allowed to determine the Fbio using the site-

specific K1 values determined by any of the procedures in appendix C to

part 63 except the proposed batch tests procedure.

The EPA believes that today's proposed revisions to the biological

treatment option adds additional flexibility without sacrificing

reduction of emissions. By separating the Table 9 compounds into 3

lists and allowing different performance requirements depending on the

properties of the compounds on the lists, additional options have been

made available to the owner/operator. The EPA maintained the original

intent of the rule by limiting the additional options to biological

units meeting the definition for enhanced biological treatment systems.

The flexibility allowed by not requiring that the site-specific

fraction biodegraded be determined for all Table 8 or Table 9 compounds

in the wastewater stream is predicated on the underlying assumption

that the wastewater is treated in an enhanced biological treatment

system. The definition for enhanced biological treatment system is

proposed in today's notice. The definition is based on extensive

discussions with individuals knowledgeable in the area of biological

treatment. Well-designed, operated, and maintained activated sludge

systems meet the definition of enhanced biological treatment systems.

12. Equations in Sec. 63.145

Many of the equations in Sec. 63.145 would be revised to make

mathematical corrections or to make the equations consistent with the

rest of the rule. The equations for control devices performance tests--

paragraph (i) in today's proposal--are proposed to be based on the

equation in the process vents section of the rule rather than the

equations in the April 1994 rule. The terms in the equations were

changed to make them consistent. Figure 1 in appendix A to subpart G

lists the new terms.

13. Compounds Not Required To Be Considered in Performance Tests

Today's proposal would add Sec. 63.145(a)(6) which specifies when

compounds are not required to be included in a performance test. These

provisions were added because EPA recognizes that not all Table 8 or

Table 9 compounds are present in a wastewater stream; and not all

compounds need to be measured to demonstrate compliance, i.e.,

measuring a predominant compound may be enough to show the mass removal

necessary to achieve compliance. These provisions would also provide

that compounds present at concentrations less than 1 ppmw at the POD or

compounds present at the POD at concentrations less than the lower

detection limit where the lower detection limit is greater than 1 ppmw

may be excluded from the performance test. This provision was added to

avoid imposing an unnecessary analytical burden.

G. Off-Site Treatment

Today's proposed amendments include provisions to allow owners and

operators of HON sources to transfer Group 1 wastewater streams or

residuals off-site for treatment provided the owner/operator obtains

from the transferee a copy of a written statement submitted by the

transferee to EPA certifying that the transferee will manage and treat

the wastewater streams or residuals in accordance with the HON's

provisions. These new provisions replace the existing provisions in

Sec. 63.132(j) that required that the owner/operator ensure that the

transferee complies with the suppression and treatment requirements of

the rule. The existing provisions in Sec. 63.132(j) are revised to

provide a means to allow transfers of treatment responsibility without

imposing liability

[[Page 43716]]

for actions of another party on the owner/operator of the HON source.

The new provisions allowing for off-site or on-site third party

treatment require the owner/operator transferring the wastewater stream

or residual to comply with the suppression requirements specified in

Secs. 63.133 through 63.137 of this subpart for each waste management

unit that receives or manages a Group 1 wastewater stream or residual

removed from a Group 1 wastewater stream prior to shipment or

transport. The owner or operator may not transfer the wastewater stream

or residual unless the transferee has submitted to EPA a written

certification that the transferee will manage and treat, in accordance

with subpart G, any Group 1 wastewater stream or residual removed from

a Group 1 wastewater stream that was received from a source subject to

the requirements of this subpart. The owner or operator has to notify

the third party treater that the wastewater stream or residual has to

be handled and treated in accordance with the requirements of the rule.

The statements of compliance with the rule by third party treaters

need only be submitted to EPA; the provisions do not contain or

envision any requirements that EPA approve the written statements

before shipments of wastewater streams or residuals to off-site

treaters are permitted. The proposed provisions provide, however, that

EPA may revoke or suspend a certification statement in the event the

off-site treater violates the pertinent HON wastewater provisions. The

proposed provisions also require that the written statement from the

off-site treater contain a statement that EPA has not revoked or

suspended a certification statement within the previous three years.

The intent of this is to provide an adequate incentive for compliance

on the part of the off-site treaters.

The proposed provisions also differ from the existing requirements

in Sec. 63.132(j) for notice from the owner/operator of the HON source

in that the requirement that notice be provided at least once a year in

the case of continuous shipments is replaced by a requirement only for

notice at the outset of such shipments and when there is a change in

the required treatment. In drafting the revised language, the general

statements of the obligation on off-site treaters in the old

Sec. 63.132(j)(3) have been replaced with explicit cross references to

the applicable requirements. This change is proposed to provide a

clearer statement of the applicable requirements and to minimize

potential for misunderstandings. This change is not considered to be a

substantive change in the requirements for off-site treaters. Another

change of significance in the provisions for third party treaters

concerns the concept of sale. The phrase in the opening paragraph of

Sec. 63.132(j), permitting the sale of Group 1 wastewater streams or

residuals ``for any other purpose'' has been eliminated in the proposed

replacement provisions. This change is necessary in light of the

revised approach to defining wastewater. Inherent in the new approach

is the concept that a stream is not wastewater unless it is being

discarded. Thus, the concept of selling wastewater is inherently

inconsistent.

H. Addition of Sec. 63.149 and Table 35

The proposed amendments to add a new Sec. 63.149 and table 35 to

subpart G are an outgrowth of the change from the POG concept of the

April 1994 rule to the POD concept in these proposed amendments. The

purpose of this new section is to ensure that the organic HAP

containing fluids are properly managed in closed systems. Table 35

lists the applicable requirements for drain or drain hub, manhole, lift

station, trench, oil/water separator, and tank.

I. Proposed Changes to Appendix C of Part 63

The EPA is proposing to revise appendix C to part 63 to clarify the

language and to add an additional procedure for determining the

fraction biodegraded in a biological treatment unit. The new procedure

added to appendix C is called the Batch test procedure.

Appendix C contains instruction on how to determine the fraction

biodegraded in a biological treatment unit. Today's proposal addresses

several issues concerning Appendix C. The first issue concerns problems

with concentrations below the detection limit for the effluent stream

from the Method 304 benchscale reactor. Another issue involving the

Method 304 reactor is the time and expense required to operate the

benchscale reactor. Both of these issues would be addressed by the

addition of the Batch tests procedure to appendix C. The proposed rule

amendments would allow owners and operators to use the batch tests to

determine first order biodegradation constants for compounds on Lists 1

and/or 2 of table 34 treated in a unit meeting the definition of an

enhanced biological treatment process. (See the discussion of

performance requirements for open biological treatment processes for

further information.)

The Batch tests procedure consists of the aerated reactor test and

the sealed reactor test. These two tests are less time intensive, and

thereby less expensive, than the Method 304 procedure. These two tests

are used widely in industry to design biological treatment units. Basic

instructions for the two tests are being added to appendix C; however,

these tests should be conducted only by persons familiar with

procedures for determining biodegradation kinetics. References were

supplied in appendix C for further information.

The appendix C requirements would be clarified by explaining that

every compound present in the wastewater would not be required to have

a site-specific, first order biodegradation constant determined. The

owner or operator can assume the first order biodegradation constant is

zero for any compound as long as the required mass removal can be

demonstrated.

J. Proposed Changes to Methods 304A and 304B

The EPA is proposing to make minor revisions to Methods 304A and

304B that would clarify several points and eliminate prescriptive

details while maintaining the quality of the data. Methods 304A and

304B are procedures that may be used to determine the biodegradation

rates of organic compounds in biological treatment processes. The

proposed revisions consist of making the terminology consistent and

allowing more flexibility in the setup and operation of the methods.

The section discussing the oxygen control system would be clarified.

References to reactor or bioreactor would be changed to benchtop

bioreactor for consistency. Additional flexibility would be added

throughout the method in numerous ways such as eliminating the

requirement for a specific size reactor or a specific blower, not

requiring a specific hydraulic residence time, allowing alteration of

the operation of the Method 304 unit to increase the effluent

concentration above the limit of quantitation, and other ways. The EPA

believes these changes will allow owners and operators more flexibility

while maintaining the original intent of the method.

K. Alternative Control Techniques (ACT) for Industrial Wastewater

The EPA believes that today's proposal makes the Industrial

Wastewater ACT internally inconsistent and is recommending that States

consider the revisions to the HON wastewater provisions definitions and

control approaches as discussed below when regulating sources covered

by the ACT. When issued in April 1994, the

[[Page 43717]]

ACT consisted of three documents: a September, 1992 draft Industrial

Wastewater Control Techniques Guideline (CTG); Revisions to Impacts of

the Draft Industrial Wastewater CTG; and the HON wastewater provisions

(as promulgated in 1994) as the model rule. The ACT was issued to

assist States in selecting Reasonably Available Control Technology

(RACT) for control of volatile organic compounds (VOC) from wastewater

at Organic Chemicals, Plastics, and Synthetic Fibers (OCPSF)

Facilities, Pharmaceutical Plants, Pesticide Sources, and Hazardous

Waste Treatment Storage and Disposal Facilities in ozone nonattainment

areas. In today's action, the EPA is proposing fundamental changes to

the wastewater provisions of the HON. The EPA believes that these

proposed amendments will result in a more effective and better-

understood regulation. Thus, some aspects of the ACT are inconsistent

with the revised wastewater provisions in the HON, and should not be

used without considering the intent of the control requirements and

these proposed revisions.

The Agency's intent has been and continues to be that the

wastewater collection and treatment control philosophy will be

consistent between the Industrial Wastewater ACT and the HON. Although

the ACT and the HON address somewhat different pollutants (not all

VOC's are HAP's, and vice-versa), the technologies and control

requirements were deliberately made consistent. Specifically, the

wastewater collection and treatment control philosophy is a basic

approach designed to minimize emissions from designated wastewater

streams meeting a certain concentration and flow rate. The approach

requires control of the transfer of the designated streams to a

treatment unit, treating the wastewater to a specified level, and

controlling emissions from the treatment unit. Although the basic

wastewater control philosophy will be the same between the HON and the

ACT, there will be major differences. The Industrial Wastewater ACT and

the HON will continue to differ in the compounds that are the basis for

control; the ACT addresses VOC emissions and the HON is concerned with

HAP emissions. The HON is a national standard for portions of the

chemical industry while the Industrial Wastewater ACT addresses

facilities in ozone non-attainment areas in four separate industry

groups, including a broader definition of the chemical industry. The

EPA still believes the RACT recommendation presented in the Draft

Industrial Wastewater CTG is reasonable; however the State agency

should consider all information presented in the Industrial Wastewater

ACT and the HON along with additional information about specific

sources to which the regulation applies.

To cite a few examples of changes to the HON that should be

considered by those referencing the Industrial Wastewater ACT: the

principle of a ``point of generation'' is being revised substantially

and renamed ``point of determination''; the definition of

``wastewater'' is being revised; and requirements are being added for

control of emissions from certain in-process streams. If the ``point of

determination'' approach is adopted, the State agency should ensure

that provisions similar to those in proposed section 63.149 are also

adopted.

V. Administrative Requirements

A. Paperwork Reduction Act

The information collection requirements of the previously

promulgated NESHAP were submitted to and approved by the Office of

Management and Budget (OMB). A copy of this Information Collection

Request (ICR) document (OMB control number 1414.02) may be obtained

from Sandy Farmer, Information Policy Branch (2136); U.S. Environmental

Protection Agency; 401 M Street, SW; Washington, DC 20460 or by calling

(202) 260-2740.

Today's changes to the NESHAP should have no impact on the

information collection burden estimates made previously. The changes

consist of new definitions, alternative test procedures, and

clarifications of requirements. The changes are not additional

requirements. Consequently, the ICR has not been revised.

B. Executive Order 12866 Review

Under Executive Order 12866, the EPA must determine whether the

proposed regulatory action is ``significant'' and, therefore, subject

to the OMB review and the requirements of the Executive Order. The

Order defines ``significant'' regulatory action as one that is likely

to lead to a rule that may:

(1) Have an annual effect on the economy of $100 million or more or

adversely affect in a material way the economy, a sector of the

economy, productivity, competition, jobs, the environment, public

health or safety in 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.

The HON rule promulgated on April 22, 1994, was considered

``significant'' under Executive Order 12866, and a regulatory impact

analysis (RIA) was prepared. The amendments proposed today would

clarify the rule and correct structural problems with the drafting of

some sections. The proposed amendments do not add any new control

requirements. Therefore, this regulatory action is considered not

significant.

C. Regulatory Flexibility Act

Pursuant to section 605(b) of the Regulatory Flexibility Act, 5

U.S.C. 605(b), as amended, Pub. L. 104-121, 110 Stat. 847, EPA

certifies that this rule will not have a significant economic impact on

a substantial number of small entities and therefore no initial

regulatory flexibility analysis under section 604(a) of the Act is

required. For the reasons discussed in the April 22, 1994 Federal

Register (59 FR 19449), this rule does not have a significant impact on

a substantial number of small entities. The proposed changes to the

rule are merely corrections and revisions that do not add new control

requirements to the April 1994 rule. Therefore, the proposed changes

are also not considered significant.

D. Unfunded Mandates

Under section 202 of the Unfunded Mandates Reform Act of 1995

(``Unfunded Mandates Act''), the EPA must prepare a budgetary impact

statement to accompany any proposed or final rule that includes a

Federal mandate that may result in estimated costs to State, local, or

tribal governments in the aggregate, or to the private sector, of $100

million or more. Under section 205, the EPA must select the most cost-

effective and least burdensome alternative that achieves the objectives

of the rule and is consistent with statutory requirements. Section 203

requires the EPA to establish a plan for informing and advising any

small governments that may be significantly or uniquely impacted by the

rule.

The EPA has determined that the action promulgated today does not

include a Federal mandate that may result in estimated costs of $100

million or more to either State, local, or tribal governments in the

aggregate or to the

[[Page 43718]]

private sector. Therefore, the requirements of the Unfunded Mandates

Act do not apply to this action.

List of Subjects in 40 CFR Part 63

Environmental protection, Air pollution control, Hazardous

substances, Reporting and recordkeeping requirements.

Dated: August 15, 1996.

Carol M. Browner,

Administrator.

[FR Doc. 96-21280 Filed 8-23-96; 8:45 am]

BILLING CODE 6560-50-P