Streamlining the General Pretreatment Regulations for Existing and New Sources of Pollution

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 9, 122 and 403

[OW-2002-0007; FRL-7980-4]

RIN 2040-AC58

Streamlining the General Pretreatment Regulations for Existing and New Sources of Pollution

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Final rule.

SUMMARY:

Today's final rule revises several provisions of the General Pretreatment Regulations that address requirements for, and oversight of, Industrial Users who introduce pollutants into Publicly Owned Treatment Works (POTWs). This final rule includes changes to certain program requirements to be consistent with National Pollutant Discharge Elimination System (NPDES) requirements for direct dischargers to surface waters. Today's action will reduce the regulatory burden on both Industrial Users and State and POTW Control Authorities without adversely affecting environmental protection and will allow Control Authorities to better focus oversight resources on Industrial Users with the greatest potential for affecting POTW operations or the environment.

DATES:

This regulation is effective November 14, 2005. For judicial review purposes, this final rule is promulgated as of 1 p.m. (Eastern Time) on October 28, 2005, as provided at 40 CFR 23.2.

ADDRESSES:

EPA has established a docket for this action under Docket ID No. OW-2002-0007. All documents in the docket are listed in the EDOCKET index at

http://www.epa.gov/edocket

. Although listed in the index, some information is not publicly available,

i.e.

, CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy form. Publicly available docket materials are available either electronically in EDOCKET or in hard copy at the EPA Docket Center, EPA/DC, EPA West, Room B102, y1301 Constitution Ave., NW, Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is (202) 566-1744, and the telephone number for the Water Docket Office is (202) 566-2426).

FOR FURTHER INFORMATION CONTACT:

Jan Pickrel, Water Permits Division, Office of Wastewater Management, Office of Water, (4203), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460; telephone number: 202-564-7904, e-mail address:

pickrel.jan@epa.gov

. Greg Schaner, Water Permits Division, Office of Wastewater Management, Office of Water, (4203), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460; telephone number: 202-564-0721, e-mail address:

schaner.greg@epa.gov.

SUPPLEMENTARY INFORMATION:

Information in this preamble is organized as follows:

A. General Information

1. Does This Final Rule Apply to Me?

2. How Can I Get Copies of This Document and Other Related Information?

3. What Process Governs Judicial Review of This Rule?

B. Under What Legal Authority Is This Final Rule Issued?

C. How Is This Preamble Organized?

D. What Is The Comment Response Document?

E. What Other Information Is Available To Support This Final Rule?

I. Background Information

II. How Was This Final Rule Developed?

III. Description of Final Rule Actions

A. Sampling for Pollutants Not Present (40 CFR 403.8(f)(2)(v) and 403.12(e))

B. General Control Mechanisms (40 CFR 403.8(f)(1)(iii))

C. Best Management Practices (40 CFR 403.5, 403.8(f) and 403.12(b), (e), and (h))

D. Slug Control Plans (40 CFR 403.8(f)(1)(iii)(B)(

6

) and 403.8(f)(2)(vi))

E. Equivalent Concentration Limits for Flow-Based Standards (40 CFR 403.6(c)(6))

F. Use of Grab and Composite Samples (40 CFR 403.12(b), (d), (e), (g), and (h))

G. Significant Noncompliance Criteria (40 CFR 403.8(f)(2)(viii))

H. Removal Credits—Compensation for Overflows (40 CFR 403.7(h))

I. Miscellaneous Changes (40 CFR 403.12(g), (j), (l), and (m))

J. Equivalent Mass Limits for Concentration Limits (40 CFR 403.6(c)(5))

K. Oversight of Categorical Industrial Users (40 CFR 403.3(v), 403.8(f)(2)(v), and 403.12(e), (g), (i), (q))

IV. Description of Areas Where EPA Is Not Taking Action on the Proposed Rule

A. Specific Prohibition Regarding pH (40 CFR 403.5(b)(2))

V. Changes to part 122

VI. Considerations in Adopting Today's Rule Revisions

VII. Regulatory Requirements

A. Executive Order 12866: Regulatory Planning and Review

B. Paperwork Reduction Act

C. Regulatory Flexibility Act

D. Unfunded Mandates Reform Act

E. Executive Order 13132: Federalism

F. Executive Order 13175: Consultation and Coordination with Indian Tribal Governments

G. Executive Order 13045: Protection of Children from Environmental Health Risks and Safety Risks

H. Executive Order 13211: Actions That Significantly Affect Energy Supply, Distribution, or Use

I. National Technology Transfer and Advancement Act

J. Congressional Review Act

A. General Information

1. Does this final rule apply to me?

Entities potentially affected by this action are governmental entities responsible for implementation of the National Pretreatment Program and industrial facilities subject to Pretreatment Standards and Requirements. These entities include:

Category

Examples of regulated entities

Local government

Publicly Owned Treatment Works.

State government

States and Tribes acting as Pretreatment Program Control Authorities or as Approval Authorities.

Industry

Industrial Users of POTWs.

Federal Government

EPA Regional Offices acting as Pretreatment Program Control Authorities or as Approval Authorities.

This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be regulated by this action. This table lists the types of entities that EPA is now aware could potentially be regulated by this action. Other types of entities not listed in the table could also be regulated. To determine whether your organization or facility is regulated by this action, you should carefully examine the applicability criteria in 40 CFR 403.3, 403.5, 403.6, 403.7, 403.8, 403.12, and 403.15 of Part 403 of Title 40 of the Code of Federal Regulations.

If you have questions about the applicability of this action to a particular entity, consult the person listed in the preceding

FOR FURTHER INFORMATION CONTACT

section.

2. How can I get copies of this document and other related information?

a.

Docket.

EPA has established an official public docket for this action under Docket ID No. W-00-27. The official public docket consists of the documents specifically referenced in this action, any public comments received, and other information related to this action. Although a part of the official docket, the public docket does not include Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. The official public docket is the collection of materials that is available for public viewing at the Water Docket in the EPA Docket Center, (EPA/DC) EPA West, Room B102, 1301 Constitution Ave., NW., Washington, DC. The EPA Docket Center Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Reading Room is (202) 566-1744, and the telephone number for the Water Docket is (202) 566-2426.

b.

Electronic Access.

You may access this

Federal Register

document electronically through the EPA Internet under the “

Federal Register

” listings at

http://www.epa.gov/fedrgstr/

or at the “Pretreatment” page at

http://cfpub.epa.gov/npdes/home.cfm?program_id=3.

An electronic version of the public docket is available through EPA's electronic public docket and comment system, EPA Dockets. You may use EPA Dockets at

http://www.epa.gov/edocket/

to view public comments, access the index listing of the contents of the official public docket, and to access those documents in the public docket that are available electronically. Although not all docket materials may be available electronically, you may still access any of the publicly available docket materials through the docket facility identified in section A.2.a. Once in the system, select “search”, then key in the appropriate docket identification number (OW-2002-0007).

3. What process governs judicial review of this rule?

Under Section 509(b)(1) of the Clean Water Act (CWA), judicial review of today's rule may be obtained by filing a petition for review in the United States Circuit Court of Appeals within 120 days from the date of promulgation of this rule. For judicial review purposes, this final rule is promulgated as of 1 p.m. (Eastern time) on October 28, 2005 as provided at 40 CFR 23.2. Under section 509(b)(2) of the CWA, the requirements of this regulation may not be challenged later in civil or criminal proceedings brought by EPA to enforce these requirements.

B. Under What Legal Authority Is This Final Rule Issued?

Today's final rule is issued under the authority of Sections 101, 208(b)(2) (C)(iii), 301(b)(1)(A)(ii), 301(b)(2)(A)(ii), 301(h)(5) and 301(i)(2), 304(e) and (g), 307, 308, 309, 402(b), 405, and 501(a) of the Federal Water Pollution Control Act as amended.

C. How is This Preamble Organized?

There is an outline for the preamble to today's final rule in the opening of this

SUPPLEMENTARY INFORMATION

section. For each distinct issue of the final rule, the preamble is written in a question-and-answer format that is designed to help the reader understand the information in the rule. Under each issue, there are subsections that provide the context for the final rule, including a discussion of the rules in place prior to today's rulemaking, the changes that were proposed, the changes that are being finalized (including significant differences from the proposal), and a summary of major comments and EPA response.

List of Acronyms

BAT—best available technology economically achievable

BCT—best conventional pollutant control technology

BOD—biochemical oxygen demand

BPJ—best professional judgment

BMP—Best Management Practice

BPT—best practicable control technology currently available

CIU—Categorical Industrial User

CFR—Code of Federal Regulations

CWA—Clean Water Act

ELG—effluent limitations guideline

EMS—environmental management system

EPA—Environmental Protection Agency

EQIP—Environmental Quality Incentives Program

FR—

Federal Register

ICR—Information Collection Request

IU—Industrial User

NODA—Notice of Data Availability

NOI—notice of intent

NPDES—National Pollutant Discharge Elimination System

NSCIU—Non-Significant Categorical Industrial User

NTTAA—National Technology Transfer and Advancement Act

OMB—U.S. Office of Management and Budget

POTW—Publicly Owned Treatment Works

PSES—Pretreatment Standards for Existing Sources

RFA—Regulatory Flexibility Act

SBA—U.S. Small Business Administration

SBAR (panel)—Small Business Advocacy Review Panel

SBREFA—Small Business Regulatory Enforcement Fairness Act

SIU—Significant Industrial User

SNC—Significant Noncompliance

SRF—State Revolving Fund

UMRA—Unfunded Mandates Reform Act

WWTP—wastewater treatment plant

D. What Is the Comment Response Document?

EPA received more than 220 comments on the proposed rule. EPA evaluated all the significant comments submitted and prepared a Comment Response Document containing the Agency's responses to those comments. The Comment Response Document complements and supplements this preamble by providing more detailed explanations of EPA's final actions. The Comment Response Document is available at the Water Docket. See Section E below for additional information.

E. What Other Information Is Available To Support This Final Rule?

In addition to this preamble, today's final rule is supported by other information that is part of the administrative record, such as the Comment Response Document, and the key supporting documents listed below. These supporting documents and the administrative record are available at the Water Docket and via e-Docket:

• Information Collection Request

• Past EPA guidance manuals and policy documents

• Stakeholder communications

• EPA data collected in support of this rulemaking

I. Background Information

A. What Is the National Pretreatment Program?

The National Pretreatment Program is part of the Clean Water Act (CWA)'s water pollution control program. The program is a joint regulatory effort by local, state, and Federal authorities that require the control of industrial and commercial sources of pollutants discharged to municipal wastewater plants (called “Publicly Owned Treatment Works” or “POTWs”). Control of pollutants prior to discharge of wastewater to the sewer minimizes

the possibility of pollutants interfering with the operation of the POTW and reduces the levels of toxic pollutants in wastewater Discharges from the POTW and in the sludge resulting from municipal wastewater treatment.

The Pretreatment Program is a core part of the CWA's National Pollutant Discharge Elimination System (NPDES) program, and it has helped communities:

• Maintain and restore watershed quality;

• Encourage pollution prevention;

• Increase beneficial uses of sewage sludge;

• Prevent formation of poisonous gases in the sanitary sewer system;

• Meet wastewater Discharge standards; and

• Institute emergency-prevention measures.

B. What Regulation Is EPA Revising?

EPA is today streamlining and clarifying various provisions of the General Pretreatment Regulations for Existing and New Sources of Pollution codified at 40 CFR Part 403. The CWA directs EPA to develop regulations in order to control pollutants which may pass through or interfere with POTW treatment processes or contaminate sewage sludge. On June 26, 1978, EPA promulgated the General Pretreatment Regulations, which established standards and procedures for controlling the introduction of wastes into POTWs (43 FR 27736). There have been a number of revisions to the General Pretreatment Regulations. The last major revisions were to implement improvements arising from the Domestic Sewage Study (Report to Congress on the Discharge of Hazardous Wastes to Publicly Owned Treatment Works) (55 FR 30082, July 24, 1990).

The General Pretreatment Regulations require POTWs that meet certain criteria to develop Pretreatment programs to control industrial Discharges into their sewage collection systems. These programs must be approved by either EPA or states acting as the Pretreatment “Approval Authority.” More than 1,400 POTWs have developed Approved Pretreatment Programs pursuant to the regulations in 40 CFR 403.8. These POTWs act as the Pretreatment “Control Authority” with respect to the Industrial Users that discharge to their systems. In the absence of an approved POTW Pretreatment Program, the State or EPA Approval Authority serves as the Control Authority.

Industrial Users of POTWs must comply with Pretreatment Standards prior to introducing pollutants into a POTW. POTWs are required to impose “local limits” to prevent Pass Through and Interference from the pollutants discharged into their systems. The General Pretreatment Regulations also include general prohibitions that forbid Industrial Users from causing Pass Through and Interference, and specific prohibitions against the discharge of pollutants that cause problems at the POTW such as corrosion, fire or explosion, and danger to worker health and safety. EPA has also developed National categorical Pretreatment Standards that apply numeric pollutant limits to Industrial Users in specific industrial categories. The General Pretreatment Regulations include reporting and other requirements necessary to implement these categorical Standards (40 CFR 403.12 (b)).

Today's final rule modifies several provisions of the existing Pretreatment Regulations. The rule includes a variety of changes which will be described further in Section E.

C. Why Is EPA Revising the Existing General Pretreatment Regulations?

By finalizing today's rule, EPA is working to improve the National Pretreatment Program to protect public health and the environment, while maintaining or improving the program's effectiveness. Although adoption of the General Pretreatment Regulations has resulted in more consistent implementation of the Pretreatment program on a national basis, many individual POTWs and Industrial Users have experienced problems implementing various requirements.

EPA's objective in finalizing today's streamlining regulation is to achieve better environmental results at a lower cost by allowing Control Authorities to better focus oversight resources where they will do the most good. The revisions in today's final rule achieve this objective by reducing the burden of technical and administrative requirements that EPA has determined provide minimal environmental benefit but consume significant resources of Industrial Users, and POTW and state Control Authorities. In designing these revisions, EPA took care to ensure that the changes being finalized do not reduce the current environmental protections in place.

The importance of finalizing today's streamlining rule was highlighted in two recent reports. The Office of Management and Budget (OMB) included the issuance of the final rule among a list of steps the Federal government would take to reduce the cost burden on the manufacturing sector. See Regulatory Reform of the U.S. Manufacturing Sector (OMB, 2005), which is posted at

http://www.whitehouse.gov/omb/inforeg/reports/manufacturing_initiative.pdf

. EPA's Office of Inspector General (OIG) also recommended that the Office of Water set milestones for finalizing this streamlining rule as part of a broader effort to improve the effectiveness of the National Pretreatment Program. See Recommendation # 4.2 of EPA Needs to Reinforce Its National Pretreatment Program (OIG, Report 2004-P-00030, September 2004), posted at

http://www.epa.gov/oig/reports/2004/20040928-2004-P-00030.pdf.

D. What Are the Roles of Key Entities Involved in the Final Rule?

EPA recognizes the role of many interested parties in the development of, and, ultimately, the successful implementation of this final rule. To the greatest extent possible, EPA has attempted to strike a reasonable balance among the many interests. A short summary of their roles is provided below.

1.

POTWs

. Publicly Owned Treatment Works (POTWs) collect wastewater from homes, commercial buildings, and industrial facilities and transport it via a series of pipes, known as a collection system, to the treatment plant. Today, there are an estimated 14,800 POTWs. Most POTWs are not designed to treat the toxics in commercial and industrial wastes which can cause serious problems. The General Pretreatment Regulations require POTWs that meet certain criteria to develop Pretreatment programs to control industrial Discharges into their sewage collection systems. These POTWs act as the Pretreatment “Control Authority” with respect to the Industrial Users that discharge to their systems. POTWs play a key role in the enforcement of the Pretreatment program through the development and implementation of Enforcement Response Plans.

2.

States.

Thirty-four states are authorized to serve as Approval Authorities for implementation of the Pretreatment Program. In the absence of an Approved POTW Pretreatment Program, the state may serve as the Control Authority.

3.

EPA

. EPA's statutory responsibility is to establish national regulations such as those covering the Pretreatment Program, which protect and restore the chemical, physical, and biological integrity of the Nation's waters. EPA also develops policy and guidance and provides training and oversight for program implementation. EPA's regional offices also serve as the Approval Authority for state

Pretreatment programs, where the state is not authorized to run the program, and as the Control Authority for POTWs without an approved Pretreatment Program in these states.

4.

Industrial Dischargers

. Industrial Users of POTWs must comply with Pretreatment Standards prior to introducing pollutants into a POTW. The General Pretreatment Regulations include general prohibitions that forbid Industrial Users from causing Pass Through and Interference, and specific prohibitions against the discharge of pollutants that cause problems at the POTW such as corrosion, fire or explosion, and danger to worker health and safety.

EPA has also developed National categorical Pretreatment Standards that apply numeric and narrative pollutant limits to Industrial Users in specific industrial categories. The General Pretreatment Regulations include reporting and other requirements necessary to implement these categorical Standards (40 CFR 403.12(b)).

5.

Other stakeholders.

Trade associations, professional organizations, environmental interest groups, and the public have an interest in the Pretreatment of industrial and commercial waste and have been involved in this rulemaking through comments and participation in stakeholder meetings.

E. What Principles Guided EPA's Decisions in This Rule?

EPA has considered the implementation of the current General Pretreatment Regulations, changes in industry, the comments on the proposed rule, and relevant studies, data, and reports in developing this final rule. The Agency has tried to ensure this final rule is based on sound science, protects existing water quality gains, and is consistent with current Pretreatment guidance and policy documents. EPA made this final rule as simple and easy to understand as possible, and has attempted to provide a clear understanding of who is affected and what they are expected to do. The hallmark of this rule is that it reduces the burden of compliance with the General Pretreatment Regulations, while at the same time protecting the environment.

F. What Are the Major Elements of This Final Rule? Where Do I Find Specific Requirements?

This section provides a summary of the major elements of this final rule and a brief index on where each of the requirements is located in the final regulations. The rule makes the following changes:

• Provides POTWs with the authority to grant monitoring waivers to industrial facilities where they document that pollutants are not present at the facility or anywhere in the wastestream. EPA notes that this authority is already available in the National Pollutant Discharge Elimination System (NPDES) regulations for point sources discharging directly to surface waters.

• Authorizes POTWs to use general control mechanisms (e.g., permits) to regulate multiple industrial dischargers that share common characteristics.

• Clarifies that POTWs can use Best Management Practices (BMPs) as an alternative to numeric limits that are developed to protect the POTW, water quality, and sewage sludge.

• Clarifies certain requirements regarding the frequency of on-site industrial facility inspections to evaluate the adequacy of controls for “Slug Discharges”.

• Provides greater flexibility in the use of certain sampling techniques, and establishes greater consistency with the sampling protocols in other parts of EPA's regulations.

• Provides the Control Authority with the discretion to authorize the use of equivalent concentration limits in lieu of mass limits for certain industrial categories, and allows the conditional use of equivalent mass limits in lieu of concentration-based limits where appropriate to facilitate adoption of new, water-conserving technologies.

• Authorizes POTWs to establish alternative sampling, reporting, and inspection requirements for certain classes of categorical Industrial Users (CIUs).

• Clarifies the definition of significant noncompliance (SNC) as it applies to violations of instantaneous and narrative requirements, and late reports, and provides additional options for publishing lists of industrial facilities in SNC annually in the newspaper. The rule also retains existing rules and policies regarding the application of Technical Review Criteria (TRC) and the use of the “rolling quarter” approach in determining SNC status.

• Provides updated references relating to requirements that POTWs must meet to adjust removal credits for combined sewer overflows (CSOs).

• Makes other miscellaneous changes designed to maintain consistency with the NPDES regulations or to correct typographical errors.

The following table indicates where these changes can be found in the General Pretreatment Regulations at 40 CFR part 403.

Issue

Section of 40 CFR 403 rules

Sampling for pollutants not present

403.8(f)(2)(v), 403.12(e)

General control mechanisms

403.8(f)(1)(iii)

Best Management Practices

403.5, 403.8(f), 403.12(b), (e), (h)

Slug control plans

403.8(f)(1)(iii)(B)(6), 403.8(f)(2)(vi))

Equivalent concentration limits for flow-based Standards

403.6(c)(6)

Equivalent mass limits for concentration-based Standards

403.6(c)(5)

Use of grab and composite samples

403.12(b), (d), (e), (g), (h)

Significant noncompliance criteria

403.8(f)(2)(viii)

Removal credits

403.7(h)

Non-Significant CIU

403.3(v)(2), 403.8(f)(2)(v), (6), 403.12(e)(1), (g), (i), (q)

Middle Tier CIU

403.8(f)(2)(v)(C), 403.12(e)(3), (i)

Miscellaneous changes

403.12(g), (j), (l), (m)

II. How Was This Final Rule Developed?

EPA initiated this effort in response to a Presidential Report on “Reinventing Environmental Regulations” (March 1995). The Report pledged to provide “more common sense and fairness in our regulations” with an ultimate goal of providing greater flexibility, reducing burden, and achieving greater environmental results at less cost. In 1995, EPA's Office of Wastewater Management started an evaluation of all of the General Pretreatment Regulations in order to identify streamlining opportunities. Based on input from various stakeholders, EPA developed issue papers that summarized 11 areas

in which the Pretreatment Regulations might be streamlined.

In May 1996, the issue papers were distributed to stakeholders (States, cities, trade associations, professional organizations, and environmental interest groups) for comment. The Agency also considered recommendations developed through a joint Association of Metropolitan Sewerage Agency (“AMSA”, now the “National Association of Clean Water Agencies”) and Water Environment Federation workshop held in 1996, which included Pretreatment experts from many stakeholder perspectives. In response to comments received on the issue papers and the joint workshop's recommendations, EPA prepared a draft proposal and preamble and distributed it for comment in May 1997. The proposed rule was published in the

Federal Register

on July 22, 1999 (64 FR 39564).

EPA received 221 sets of comments on the proposed rule. Comments were received from individual POTWs and Industrial Users, trade groups representing those interests, states, and one environmental organization (the Natural Resources Defense Council). In finalizing this rule, EPA carefully reviewed the issues raised in the public comments. Due to the intervening time between the proposed and final rules, EPA also revisited the major assumptions underlying each rule change to verify that these assumptions were still valid. In a few areas, this process required research or additional data to support certain provisions, and discussions with stakeholders expressing continued interest in the rule regarding their comments on the proposed rule.

III. Description of Final Rule Actions

Today's final rule addresses 12 specific issues and a few miscellaneous changes pertaining to the General Pretreatment Regulations. This section describes the context of these changes, records how the proposal and final rule differ, and summarizes EPA's rationale for specific actions and how the Agency responded to significant comments.

EPA notes that capitalized terms in this and other sections (e.g., categorical Pretreatment Standards, Interference, Pass Through, etc.) should signal to the reader that these are terms defined in 40 CFR 403.3.

A. Sampling for Pollutants Not Present (40 CFR 403.8(f)(2)(v) and 403.12(e))

Today's rule allows the Control Authority to authorize an Industrial User subject to categorical Pretreatment Standards to forgo sampling of a pollutant if the Industrial User demonstrates through sampling and a technical evaluation of its facility operations, that a given pollutant is neither present nor expected to be present in the Discharge, or is only present at background levels from intake water without any increase in the pollutant due to the activities of the Industrial User. There is similar language in EPA's NPDES permitting regulations for direct dischargers. See 40 CFR 122.44(a)(2). The POTW Control Authority to which the Industrial User discharges may also reduce its monitoring for the pollutant to once during the term of the Categorical Industrial User's control mechanism. Note that in the discussion of this issue, when EPA uses the phrase “pollutants not present” it is using this phrase as short-hand for “pollutants neither present nor expected to be present above background levels”. In addition, because the requirements of 40 CFR 403.8(f)(2) apply to POTWs with approved Pretreatment programs rather than Control Authorities in general, the discussion here distinguishes between the authority granted to Control Authorities in 40 CFR 403.12(e) to waive monitoring for pollutants not present, and the reduction in monitoring requirements for POTWs for these pollutants in 40 CFR 403.8(f)(2)(v).

1. What Were the Rules in Place Prior to Today's Rulemaking?

Section 403.12(e)(1) required Industrial Users subject to categorical Pretreatment Standards to submit reports to the Control Authority at least twice each year indicating the nature and concentration of all pollutants in their effluent that are limited by an applicable Standard. Prior to today's rulemaking, the Control Authority was not authorized to reduce monitoring of pollutants regulated by the applicable categorical Pretreatment Standard to less than twice per year. 40 CFR 403.8(f)(2)(v) also required POTWs to sample these Industrial Users at least annually to independently verify compliance with the Standard. Semiannual sampling by the Industrial User and annual sampling by the POTW was required for all pollutants limited by the categorical Pretreatment Standard even if certain pollutants regulated by the Standard were not reasonably expected to be present.

2. What changes did EPA propose?

The proposal would amend the current regulation to authorize the Control Authority to waive the sampling requirements for an Industrial User subject to a categorical Pretreatment Standard for a pollutant if the pollutant was not expected to be present in the wastestream in a quantity greater than the background level present in its water supply, with no increase in the pollutant in the wastewater attributable to the industrial process. In lieu of monitoring for the pollutants determined not present, the Industrial User would submit a certification as part of its semiannual monitoring reports that there had been no increase in the pollutant in its wastewater due to its activities. This change would also reduce a POTW's sampling requirement once it had determined that a pollutant was not expected to be present. However, as proposed, the reduced sampling would not have been available to facilities subject to the Organic Chemicals, Plastics, and Synthetic Fibers (OCPSF) guidelines, 40 CFR part 414.

3. What changes is EPA finalizing in today's rule?

Today, EPA is adopting the proposed changes which authorize a Control Authority to waive the monitoring requirements in semiannual reports required under 40 CFR 403.12(e) for individual pollutants, including indicator or surrogate pollutants, for an Industrial User subject to a categorical Pretreatment Standard. A Control Authority may waive this requirement if it determines that the pollutant is neither present nor expected to be present, at levels greater than that of the intake water, without any increase in the pollutant due to the activities of the Industrial User. The waiver will not be available for monitoring required for the baseline monitoring report required under 40 CFR 403.12(b) or the 90-day compliance report required under 40 CFR 403.12(d). The Industrial User must continue to conduct at least twice-per-year monitoring until the waiver is both granted by the Control Authority and incorporated into the Industrial User's control mechanism. The POTW's annual monitoring requirements for the pollutant for which a monitoring waiver is granted may be reduced to a minimum of once during the effective period of the Industrial User's control mechanism.

In finalizing the rule, EPA is making the following changes to the proposed rule:

Coverage for OCPSF Facilities:

EPA has determined that it is appropriate for the monitoring waiver to be available to Industrial Users subject to the OCPSF guidelines and is not limiting the availability in any way different from other Categorical Industrial Users.

Industrial User Sampling Data:

The final rule requires that to demonstrate that the pollutant is not present, the Industrial User must provide the results of one or more samples prior to treatment which are representative of all process wastewater.

Notice to Control Authority if Pollutant Found to be Present:

The final rule includes a provision which requires that in the event that a pollutant is subsequently found to be present or is expected to be present, the Industrial User must immediately resume monitoring and notify the Control Authority.

Control Mechanism Issues:

EPA clarifies that the Control Authority must include any waiver granted to an Industrial User in the User's control mechanism. The Control Authority must also document the reasons for authorizing the waiver and maintain any information submitted by the User in support of the waiver for at least three years after expiration of the waiver. The waiver is valid only for the duration of the control mechanism. In order to continue the waiver for the period of the next control mechanism, the Industrial User will need to reapply for the waiver, including the submission of appropriate monitoring data. The control mechanism must include the requirement for the Industrial User to immediately notify the Control Authority in the event that the pollutant is found or suspected to be present, and to resume monitoring at least semiannually. The control mechanism still must include all applicable categorical Standards, even those Standards for which monitoring has been waived.

Waiver Does Not Supercede Other Certifications:

EPA has included a provision which states that the waiver of monitoring requirements cannot replace any certification requirements that have been established in specific categorical Pretreatment Standards.

4. Summary of Major Comments and EPA Response

How does EPA define “not present?”

In the preamble to the proposed amendments, EPA specifically requested comment on how to define what is meant by “not present.” Several commenters suggested that a precise definition was not necessary based on the regulatory context. Other commenters suggested that it be defined in terms of a percentage of the applicable limit, while others suggested that the term be defined as at or below the levels found in the water supply. The final regulatory language clearly indicates that monitoring for a pollutant can be waived as long as the levels in the untreated wastewater do not exceed the levels in the intake water based on “sampling and other technical factors.” EPA did not promulgate a definition of not present when the similar NPDES revision was finalized, and EPA continues to view the final regulatory language as sufficiently clear to avoid confusion.

In response to commenters that suggested that “not present” be defined as a percentage of the applicable categorical Standard, EPA notes that today's waiver is not for pollutants that are not reasonably expected to violate the Standard, but rather for pollutants that are neither present nor expected to be present in the Discharge above background levels. Therefore, the level of pollutant in the Discharge in relation to the Standard is not the relevant benchmark for the Control Authority's determination whether the waiver request should be granted. Instead, what matters in the determination is whether the Industrial User's practices or industrial processes add the pollutant. The Control Authority already has the ability to reduce monitoring to as infrequently as twice per year for any pollutants that are in the Discharge but are not reasonably expected to violate the Standard. However, if the background level from the Industrial User's intake water already exceeds the applicable categorical Standard, a waiver of the monitoring requirements would not be available unless the Control Authority has adjusted the categorical Standard using the net/gross provision of 40 CFR 403.15, and the pollutant is not added to the wastewater by the discharger's practices or processes.

Several commenters also suggested that if a pollutant is added in “negligible” amounts or in amounts equal to “typical” domestic levels, the Control Authority should still be authorized to grant the monitoring waiver. EPA addressed this issue in the preamble to the final NPDES regulation dealing with a waiver of monitoring requirements for direct dischargers. There, EPA stated:

“EPA declines to allow monitoring waivers for pollutants that are added by dischargers in minute amounts (e.g., use of common cleaners or from research operations) because human activity might lead to substantial increases in those pollutant Discharges which may threaten the aquatic environment. Consequently, there is a continuing need to monitor those pollutants. EPA also notes that at least one national effluent guideline addresses the introduction of incidental amounts of pollutants from cleaning, maintenance, or research operations and EPA does not believe it is appropriate to apply the waiver to a pollutant that is added to the wastestream and subject to an effluent guideline. See 40 CFR 414.11(b) (applying the Organic Chemicals, Plastics, and Synthetic Fibers Effluent Guidelines to wastewater Discharges from research and development operations). Metals or other pollutants that can leach from pipes may also pose a threat to the environment and EPA believes monitoring should be retained for such Discharges. With respect to pollutants which occur in amounts below “levels of concern”, the discharge of such pollutants can also increase from human activity and EPA believes that monitoring is necessary to ensure that an appropriate level of treatment continues to be provided.” (65 FR 30892, May 15, 2000).

Nothing submitted by commenters has changed the Agency's mind in the case of indirect dischargers with respect to its earlier conclusion.

Some commenters also suggested that EPA clarify that the term “quantities” as used in the proposal may mean mass loading in addition to concentration. EPA agrees that there may be instances where the use of mass may be more appropriate than concentration, and therefore will allow Control Authorities to use pollutant mass to compare the levels of pollutants in the wastewater to the levels of pollutants in the intake water. If the Industrial User can demonstrate through its technical evaluation that a specific pollutant is not added, and can demonstrate through a mass balance that any increases in the wastestream concentration are due only to evaporative losses or other similar reductions in the volume of wastewater discharged, then a monitoring waiver may be approved by the Control Authority. Note that accurate flow measurements will be necessary to perform the appropriate mass-balance calculations and demonstrate that small amounts of the pollutant are not added in the course of the facility activity. One example submitted by a commenter notes that cooling tower maintenance chemicals may add the pollutant of concern to the wastestream. If the pollutant of concern is added by the User in any way to the wastestream, then the Industrial User would not be eligible for the waiver. To the extent that the concentration is increased significantly such that it may impact the POTW, EPA would expect that a monitoring waiver would not be granted. In response to this comment, EPA is revising the language in the final regulation to refer to the “levels” of pollutants in the intake water rather than the “concentration” of pollutants in the intake water. This wording change is consistent with the similar NPDES permitting requirement for

direct dischargers (see 40 CFR 122.44(a)(2)(i)).

One commenter noted that EPA's use of the phrase “with no increase in the pollutant due to the regulated process” could create confusion in how to handle pollutants that are added in other facility wastestreams that are not regulated by the applicable categorical Pretreatment Standard. EPA agrees that the phrase “with no increase in the pollutant due to the regulated process” is not appropriate. Although the phrase was used in the preamble to the proposal and not the proposed regulation, EPA is revising the final regulatory language to include the phrase “without any increase in the pollutant due to the activities of the Industrial User”. This phrase better reflects EPA's intent that the waiver would not be available for a pollutant where the Industrial User may add the pollutant through means other than the regulated industrial process (except for sanitary wastewater—see below).

Should Industrial Users have the authority to waive sampling requirements rather than the Control Authority?

Several commenters suggested that it would be appropriate for the Industrial User to have the authority to make the determination on whether a pollutant is present and monitoring requirements should be waived rather than the Control Authority. EPA disagrees that Industrial Users rather than the Control Authority should have the authority to waive monitoring for pollutants not present. The Control Authority is the regulatory agency responsible for ensuring compliance with applicable Standards, and is therefore the most appropriate agency for determining the monitoring requirements necessary for it to fulfill that responsibility. In addition, placing the authority with the Industrial User eliminates oversight that, in EPA's view, is necessary to ensure that this provision is implemented correctly.

What information is necessary to determine if a pollutant is not present at a facility?

EPA received many comments suggesting what type of data is needed in order to make an informed decision on whether a pollutant is neither present nor expected to be present. Commenters noted that information contained in control mechanism applications and baseline monitoring reports, as well as data obtained through a thorough facility inspection could all be used to support a determination that a pollutant is not present. The commenters noted that these are all mechanisms for obtaining data on the raw materials, products, and by-products used and generated at an Industrial User. EPA agrees that these are valid sources of information that can contribute to an Industrial User's demonstration that a pollutant is neither present nor expected to be present. EPA notes that the Industrial User monitoring waiver in today's rule applies to the semiannual monitoring required under 40 CFR 403.12(e), and does not apply to monitoring required for the baseline monitoring report or the 90-day compliance report. EPA has also concluded that if the Control Authority uses a control mechanism application form, such a form is an appropriate place for the Industrial User to request the monitoring waiver, although the mechanism for how the request is made is largely up to the discretion of the Control Authority.

Commenters also suggested that material safety data sheets would be a valuable tool in determining whether specific pollutants are present in the raw materials or other chemicals used at the facility. EPA notes that material safety data sheets do not identify all of the pollutants present in a given material, and therefore cannot be relied upon to determine whether a pollutant is present in the raw materials or other chemicals at the Industrial User's facility. In order for the Control Authority to accurately determine the presence of a pollutant in a given raw material or other chemical, the Industrial User will need to analyze the material in question, or obtain a certificate of analysis from the manufacturer of the material demonstrating the absence of the pollutant. In addition, the evaluation needs to include materials not necessarily used for the product, such as chemicals used in equipment cleaning and wastewater treatment. Although wastewater treatment chemicals are used to reduce the levels of pollutants in the Discharge, analysis of the chemicals can show significant levels of contaminants that can be added to the wastewater stream. Additional information, such as intermediate products, final products, and byproducts generated in the process will need to be considered as well, and therefore a detailed knowledge and evaluation of the process chemistry involved in the manufacturing operations will be necessary.

Some commenters suggested that the determination of whether a pollutant is present should be based exclusively on a review of available information. While available information should certainly be used in the determination, and EPA would expect that most Industrial Users requesting the waiver would have a fairly extensive knowledge of the pollutants present in their wastewater, because the pollutants are either directly added or generated as byproducts, an Industrial User cannot assume that a pollutant is not present in its Discharge simply because it has not generated any information to suggest otherwise. EPA notes that the Industrial User has the burden to demonstrate that the pollutant is not present, and if this demonstration cannot be made to the satisfaction of the Control Authority, the waiver may not be granted.

EPA does agree that the determination of whether a pollutant is present should be based on whether or not that pollutant would have the potential to enter the wastestream to the POTW. Such an evaluation must include the potential for the pollutants to enter the wastestream through spills and other potentially infrequent events, in addition to whether the pollutant would be routinely expected to enter the wastestream. Therefore, in order for monitoring for the pollutant to be waived, there must be a high degree of certainty that the pollutant will not show up in the Discharge to the POTW.

EPA also notes that for facilities that use the combined wastestream formula, “unregulated” wastestreams may be covered by the categorical Standard through the adjusted Standard. Therefore, EPA has concluded that it is not appropriate to allow a monitoring waiver where wastestreams other than those regulated by the categorical Standard contribute the pollutant of concern. However, since pollutants, especially metals, may be present in sanitary wastestreams at higher than background concentrations, and because sanitary wastestreams are not typically regulated through categorical Standards specifically or the Pretreatment program in general, the revised regulation provides that waivers may be granted where the only source of the increase in the pollutant from human activity is sanitary wastewater, provided that the sanitary wastewater is not regulated by an applicable categorical Standard and does not include the pollutant at levels that are significantly higher than typical domestic levels for the POTW's service area. See 40 CFR 403.12 (e)(2)(i).

One commenter noted several industries that claimed that a pollutant was not present in their Discharge, only to have it show up in monitoring results. EPA is aware of similar instances and knows of circumstances where the pollutants are later detected in the sampling data at fairly high levels. This is one of the reasons why EPA is requiring that the technical evaluation of the facility to determine the presence of the pollutant be

supported by sampling data, including data prior to treatment. Even though EPA is generally not requiring a minimum amount of data (with the exception of the one sample required prior to treatment), Control Authorities are expected to have sufficient sampling data to support the technical evaluation. Where monitoring data shows that the pollutant is present at levels above the background intake water level, the Control Authority must deny the request for the monitoring waiver.

How much sampling data is necessary to make a determination that a pollutant is not present?

Comments on this issue varied from suggesting that no sampling is necessary to providing suggestions on specific sampling frequencies for the intake water as well as the effluent Discharge. One commenter suggested that no influent monitoring data was necessary if the effluent data shows no detectable levels of the pollutant. Although EPA has concluded that some sampling data is necessary to document the absence of a pollutant in the Discharge, the amount of sampling necessary for the determination is most appropriately determined on a site-specific basis, and will depend, in part, on how convincing are the arguments regarding the “other technical factors”. Therefore, EPA is not establishing a minimum monitoring frequency. This is also consistent with the NPDES regulations, which do not establish a minimum sampling frequency. EPA is, however, establishing a minimum requirement that one sample be collected prior to treatment. Data prior to treatment is necessary to demonstrate that the measured levels reflect any pollutants that are added to the wastewater rather than the levels after they have been reduced by treatment, since effective treatment could become less effective over time. Other data that may be used in the evaluation include final effluent data and in many cases the facility intake water.

It is important to note that the pollutant monitoring waiver is based on a facility-wide evaluation and, therefore, sampling data must be representative of all wastestreams, as well as any seasonal or other variability in the Discharge. In addition, note that the monitoring waiver is for pollutants that are neither present nor expected to be present, and not for pollutants which are added but for which no violation of the applicable Standard is expected. In some cases, the existing monitoring data will be sufficient to evaluate the presence of the pollutant in the Discharge. The data prior to treatment is less likely to have been collected in the past, although historic data, if still representative, can be used.

EPA has concluded that a sequential approach to sampling is the most appropriate way to evaluate the request for a monitoring waiver based on sampling data. If monitoring of the Industrial User's wastewater prior to treatment (and after treatment where appropriate) shows no detectable levels of the pollutant based on the most sensitive EPA approved method, then no sampling of the intake water is necessary because the levels of the pollutant in the Discharge will already have been shown to be at or below the levels in the intake water. However, if a pollutant is present in the Industrial User's wastewater, data on the levels in the influent water are necessary to determine whether the presence of the pollutant is solely the result of levels in the influent water, or the result of the Industrial User adding the pollutant to some extent. Background levels of pollutants in an Industrial User's influent water will vary from POTW to POTW, and possibly from Industrial User to Industrial User based on many factors. If historical data is available, based on prior sampling by either the Industrial User or the POTW, or based on drinking water system data that is representative of the Industrial User's intake water, additional sampling may not be necessary.

EPA notes that data for intake water must be representative of the water typically used at the facility, but prior to any water treatment or conditioning provided by the Industrial User. This generally means that the data, especially for lead and copper, should reflect pollutant levels of intake water that have been running continuously for at least several minutes, rather than pollutant levels of intake water that have been sitting in the pipes for several hours. Water system data for lead and copper will typically reflect the levels of pollutants in the water after it has been sitting in the pipes for at least six hours. Because this data is not generally representative of the levels of lead and copper in the typical facility intake water, drinking water data for lead and copper may not be representative of the Industrial User's actual intake water and should not be used unless the Industrial User can demonstrate to the satisfaction of the Control Authority that the lead and copper levels are actually representative.

How should Control Authorities and Industrial Users address analytical variability when determining if a pollutant is present above background levels?

One commenter requested clarification on how to handle a situation where the Industrial User and the Control Authority had determined that a pollutant was not present, but subsequently found slightly higher levels based on monitoring data. EPA acknowledges that there is some variability in sample results. Therefore, it is possible that slightly higher levels of pollutants may be measured in the Industrial User's wastewater than in the intake water. If the higher levels are within the method variability and the technical evaluation shows that the pollutant is neither present nor expected to be present, then the results should be considered equal. If the higher levels are above the method variability, then the pollutant should be considered to be present unless the Industrial User can demonstrate that the sample result was in error, or that the intake levels of the pollutant have risen to the same extent. EPA notes that the burden is on the Industrial User to demonstrate that an analytical error has occurred through re-analysis of the sample or other similar means. An unexpected result is not sufficient justification to consider a sample result to be in error since, as noted above, sampling data at times finds pollutants which were not expected to be present. Likewise, the Industrial User would need to provide sampling data demonstrating that the levels of the pollutant in question have risen in the intake water if it believes that this is the reason for the higher levels of the pollutant in its wastewater.

Should any ongoing POTW monitoring be required to demonstrate that the waived pollutant continues to be absent from the Discharge?

Not all commenters agreed with the EPA proposal requiring POTW's to monitor for any waived pollutants at least once during the effective period of the Industrial User's control mechanism. These commenters believed that the combination of the certification and the requirement to report changes in the Discharge were sufficient to ensure that the Control Authority would become aware of changes that would require a resumption of monitoring. Other commenters believed that the once per control mechanism term was appropriate and would not burden POTWs, while other commenters believed that monitoring once per year for the waived pollutants was appropriate. EPA disagrees that annual monitoring will be necessary to determine whether or not the pollutant is present. As stated in the preamble of the proposal, EPA asserts that if the Control Authority has determined, based on both sampling data and a

technical evaluation, that a pollutant is not present at levels above background, and if the Industrial User continues to certify that there is no increase in the pollutant in its wastewater due to the activities of the Industrial User, then it is appropriate to allow the Control Authority to determine whether to sample the facility more frequently than once during the term of the control mechanism. EPA received no data to suggest that more frequent monitoring is necessary. EPA notes that the Control Authority has the discretion to determine that the Industrial User must monitor for a pollutant despite the User having demonstrated that it is not present. Where the Control Authority elects to require monitoring in such circumstances, it may determine the appropriate frequency of monitoring, including frequencies that are less than twice per year. In addition, the Industrial User may also monitor on its own, even though the requirement to do so has been waived, but in this case the Industrial User must report the results of that monitoring to the Control Authority in accordance with 40 CFR 403.12(g)(6).

Although EPA is not requiring annual monitoring by the POTW, EPA has concluded that at least one effluent sample during the term of the Industrial User's control mechanism is necessary to confirm that no changes have occurred, and that the monitoring waiver is still appropriate. EPA is requiring that this monitoring be done by the POTW to ensure an independent assessment of the Industrial User. EPA has concluded that the most appropriate time for the monitoring to occur is during the renewal of the control mechanism. However, EPA also asserts that the timing is best left to the discretion of the POTW and, therefore, is not requiring that the monitoring occur at any specific time during the duration of the control mechanism.

Should the waiver be available for pollutants that in the past have caused Pass Through or Interference, or otherwise caused problems at the POTW?

One commenter suggested that the monitoring waiver for pollutants not present should not be available for pollutants which have been problematic for the POTW in the past. EPA agrees that POTWs must be more careful when waiving the monitoring requirements for pollutants for which the POTW has previously experienced problems. In these instances, more monitoring data and a more careful review of the technical evaluation is warranted. However, if the pollutant is truly not present at the facility or in the Discharge and there is no potential for spills or slug loads of the pollutant, EPA does not view it as necessary to require monitoring at that Industrial User's facility merely because the pollutant was associated with past POTW problems and, therefore, will not prohibit granting a waiver in these circumstances. Granting the waiver is at the discretion of the Control Authority, and where there has been a history of problems with a pollutant at the POTW, the Control Authority may deny a waiver, if it deems this necessary to prevent future problems.

Is the waiver available for facilities subject to the Organic Chemicals, Plastics, and Synthetic Fibers category?

Most comments supported allowing waiver of the monitoring requirements for pollutants not present for facilities subject to the OCPSF Standards. EPA agrees that Control Authorities should be able to grant the monitoring waiver to OCPSF dischargers if appropriate. Several commenters indicated that they know of OCPSF facilities that manufacture a limited number of products and have fairly consistent Discharges. A monitoring waiver for some regulated pollutants may be appropriate for such facilities and, therefore, a blanket exclusion for all OCPSF facilities from the waiver would not be appropriate. However, EPA notes that production and Discharges from OCPSF facilities can be highly variable. Control Authorities must ensure that sufficient information, including sampling data, is available to assess whether a particular pollutant is present at any time, taking into consideration all of the variability in production. When a particular pollutant may be present at some time based on the products that are manufactured at the facility, even if the pollutant is not currently present, a monitoring waiver for that pollutant would not be appropriate. If any facility's operations, regardless of whether they are subject to OCPSF Standards or not, are sufficiently variable that a reasonable determination cannot be made as to whether a pollutant will consistently be absent from the Discharge, the Control Authority may not grant a waiver.

How does the waiver for pollutants neither present nor expected to be present affect other waivers specifically included in a categorical Pretreatment Standard, such as the option under the metal finishing Standards allowing for implementation of a toxic organics management plan in lieu of monitoring for total toxic organics?

Several commenters compared the waiver of monitoring for pollutants not present being promulgated today to other monitoring waivers such as the management plan and certification option under the metal finishing Standards in lieu of total toxic organics monitoring. In order to avoid any potential confusion, EPA is adding specific language to today's regulations which states that the monitoring waiver and certification for a pollutant that is not present cannot be used in place of any certification process established in categorical Pretreatment Standards. Therefore, today's monitoring waiver would not be available, for example, for total toxic organics under the metal finishing regulations. Rather, in order to reduce its monitoring for total toxic organics, a metal finisher would need to use the management plan and certification process contained in 40 CFR 433.12. Since the metal finishing and other category-specific certifications were established for an identified set of facilities based on an evaluation of those facilities, while today's monitoring waiver is being established generally without a reevaluation of each categorical Pretreatment Standard, EPA has concluded that it is not appropriate for today's waiver to supercede these more specific certifications. EPA notes that the equivalent NPDES Permit requirement includes this same provision. See 40 CFR 122.44(a)(2)(v). However, while the general waiver for pollutants neither present nor expected to be present cannot substitute for a category-specific certification requirement, the data and analyses that would otherwise be used to support such a waiver may be relevant to, and if so form part of the basis for, the category-specific certification.

While today's rule provides that the monitoring waiver and certification for a pollutant that is not present cannot be used in place of any certification process already established in existing categorical Pretreatment Standards, the monitoring waiver is available for pollutants that are analyzed as surrogates for other pollutants.

What happens if a facility's operations change so that a pollutant for which a monitoring waiver has been granted is now present at the facility?

Several commenters correctly noted that 40 CFR 403.12(j) requires that Industrial Users provide notification of any substantial changes in the volume or character of pollutants in the Discharge. This notification requirement would apply in the event that a pollutant for which monitoring was waived became present at the Industrial User for any reason. However, the language in 40 CFR 403.12(j) refers to pollutants in the Industrial User's Discharge rather than any pollutant at the facility which is or may be added to the wastestream.

Therefore, in order to clarify the requirement for waived pollutants, EPA has added language to the final regulation that states that notification is necessary, and that the Industrial User must immediately resume monitoring, if the pollutant is found or suspected to be present. The requirement to resume monitoring would apply even before the Industrial User's control mechanism is revised to reflect the resumed monitoring. Control mechanisms that include the monitoring waiver must also include language requiring notification and the resumption of monitoring in the event that a pollutant is subsequently determined to be present at the facility. Failure to provide the required notification or to resume monitoring is a violation of the Industrial User's control mechanism and the General Pretreatment Regulations. EPA also recommends that any control mechanism issued incorporating a monitoring waiver includes a reopener clause which allows the Control Authority to revise or revoke the waiver if appropriate.

Where a facility has been granted a waiver of monitoring for a pollutant that has been determined not to be present and it installs or constructs new production lines or processes, the Industrial User must evaluate the new production lines or processes and determine whether they may cause the pollutant to be present, in which case the facility must resume monitoring.

How often will certification that the pollutant is not present in the Discharge be required?

EPA proposed that certification that a pollutant is not present at the facility be submitted twice-per-year with the semiannual reports otherwise required under 40 CFR 403.12(e). Several commenters supported this approach, while others believed that a once-per-year certification would be sufficient, or that no certification should be required, especially since the Industrial User is required to report changes at the facility to the POTW. EPA has concluded that twice-per-year certification will not impose a significantly greater burden on Industrial Users than once-per-year certification since in most cases the reports would still be submitted at least twice-per-year even if monitoring for some pollutants is waived. In addition, it often may be easier for the Industrial User to include the certification with every report rather than determining which reports need the certification and which do not. Although required to report changes in the facility, an Industrial User's willingness to certify that the pollutant is not present in the Discharge provides an additional assurance that the pollutant is not present above background levels. Accordingly, EPA has decided to maintain the twice-per-year certification requirement.

In addition, EPA has clarified the language of the certification requirement to state that once an Industrial User has received a monitoring waiver, the certification is required and is not optional. If the Industrial User is no longer certain that the pollutant is not present, it must notify the Control Authority and immediately begin monitoring. EPA intends that the monitoring waiver be used in instances where a pollutant is consistently not present at a facility, and is not to be used for short periods of time when the pollutant is not present.

It should be noted that the certification provided in the 40 CFR 403.12(e)(2)(v) includes two blank spaces which are to be filled in by the Industrial User. In the first blank space, the Industrial User is to specify the applicable Pretreatment Standard(s) that apply to the facility (e.g., 40 CFR 433.15). In the second blank space, the Industrial User is to list the pollutants for which the monitoring waiver has been granted. As noted above, the certification must include all of the pollutants for which a monitoring waiver has been granted. The Control Authority may also fill in the blank spaces before incorporating the certification language into the Industrial User's control mechanism for use by the Industrial User with the semiannual or more frequent reports.

Should the waiver be available for new Industrial Users, or during an Industrial User's first control mechanism?

EPA noted in the preamble to the proposed rule that the equivalent NPDES provision did not allow the monitoring waiver to be granted to New Sources/New Dischargers for the term of their first NPDES Permit. Comments on this issue were divided, with some commenters noting that the term of the first control mechanism is a good time to collect data on the presence of the pollutant at the facility, while other commenters believed that the Control Authority would generally be able to determine the presence of the pollutant, even for the first control mechanism. It is EPA's view that the Control Authority may need time to collect enough data to appropriately assess whether pollutants at a new Industrial User are consistently not present and, therefore, should be cautious in approving a waiver for new Industrial Users. Time may be necessary to determine whether there are seasonal or other variations in the operations that would result in the pollutants being present periodically. However, the length of time needed to collect the data and make the assessment will vary depending on site-specific factors. Therefore, EPA has not included language in the regulation restricting the eligibility of a new Industrial User for a monitoring waiver for pollutants that are not present.

What documentation of the waiver is required?

Several commenters noted the need to document the waiver when it is approved by the Control Authority. EPA agrees that this documentation is important for the Approval Authority and the general public to ensure that waivers are properly granted. Pursuant to 40 CFR 403.14, this information must be made publicly available. It has always been EPA's intent that any monitoring waivers would be documented in the Industrial User's control mechanism. Today's regulation also specifically requires that the Control Authority's rationale for granting the waiver and any information submitted by the Industrial User in its request for a monitoring waiver be maintained by the Control Authority for at least three years after the expiration of the waiver.

B. General Control Mechanisms (40 CFR 403.8(f)(1)(iii))

Today's final rule clarifies that POTWs may use general control mechanisms, such as general permits, to regulate the activities of groups of Significant Industrial Users (SIUs). Provided that the necessary legal authority exists, the POTW may use a general control mechanism for any facilities that meet certain minimum criteria for being considered substantially similar.

In the NPDES permitting context, the use of general permits (see 40 CFR 122.28) allows the permitting authority to allocate resources in a more efficient manner and to provide timelier permit coverage. For example, direct dischargers with common characteristics may be covered under a general permit without the permitting authority expending time and money to issue individual permits to each of these facilities. The use of a general permit also ensures consistency of permit conditions for similar facilities. In the Pretreatment context, POTWs might benefit from the use of control mechanisms for Discharges from SIUs to POTWs which are similar to the general permits used in the NPDES program.

This modification should help POTWs by providing a cost-effective method to cover large numbers of similar facilities under a single mechanism. This is expected to reduce

the administrative burden of issuing separate mechanisms to similar facilities.

1. What were the rules in place prior to today's rulemaking?

Prior to today's rulemaking, the Pretreatment Regulations allowed POTWs to use general control mechanisms to control non-Significant Industrial Users, but required individual control mechanisms for SIUs. Section 403.8(f)(1)(iii) required POTWs to “Control through, order, or similar means, the contribution to the POTW by each Industrial User to ensure compliance. * * * In the case of Industrial Users identified as significant * * *, this control shall be achieved through s or equivalent individual control mechanisms issued to each such User.” The preamble to the regulation which originally required control mechanisms for SIUs emphasized the importance of POTWs evaluating SIUs on an individual basis to determine the need for individual requirements as necessary. See 55 FR 30082 (July 24, 1990).

2. What changes did EPA propose?

EPA proposed to revise the regulation by authorizing POTWs to use “general permits” to regulate SIUs in certain circumstances. Under the proposal, all of the facilities to be covered by a general permit must employ the same or substantially similar types of industrial processes; discharge the same types of wastes; require the same effluent limitations; and require the same or similar monitoring. These requirements reflect the existing criteria for using general permits for direct dischargers at 40 CFR 122.28(a)(2)(i). EPA also indicated that the use of a general permit does not relieve the SIU from any reporting or compliance obligations under Part 403.

3. What changes is EPA finalizing in today's rule?

In today's rule, EPA is finalizing the proposed rule's change to allow the use of general control mechanisms for SIUs. Section 403.8(f)(1)(iii) contains the revisions which authorize general control mechanisms.

EPA notes that today's rule replaces the term “general permit” with “general control mechanism”. This terminology is more consistent with the existing Pretreatment Regulations which require that SIUs be controlled through “permits or equivalent individual control mechanisms.” Just as EPA has not precluded the use of an “order or similar means” to regulate individual SIUs, it also is not ruling out the use of other mechanisms besides permits to address groupings of SIUs. This decision is based on the rationale EPA provided when the Agency first promulgated the requirement that POTWs regulate SIUs through individual control mechanisms to SIUs. See 55 FR 30107, July 24, 1990. EPA is including the relevant passage from this final rule for reference:

“* * * the Agency will require issuance of “individual Discharge permits or equivalent control mechanisms.” An adequate equivalent control mechanism is one which ensures the same degree of specificity and control as a permit. To clarify that the conditions of the individual control mechanism must be enforceable against the Significant Industrial User through the usual remedies for noncompliance (set forth in 40 CFR 403.8(f)(1)(vi)(A), EPA has amended the language of 40 CFR 403.8(f)(1)(vi)(B) to provide that Pretreatment requirements enforced through the remedies of 40 CFR 403.8(f)(1)(vi)(A) shall include the requirements set forth in individual control mechanisms. In addition, the Agency has added to proposed 40 CFR 403.8(f)(1)(iii) a statement that individual control mechanisms must be enforceable.

What types of facilities may be subject to a general control mechanism?

SIUs that are covered by concentration-based Standards and Best Management Practices may be subject to general control mechanisms. However, due to the requirement that all facilities covered under the same mechanism “require the same effluent limitations”, facilities regulated by categorical Standards expressed as mass limits, which are inherently unique to each individual User, can not receive coverage under a general control mechanism. The one exception to this exclusion would be situations where the POTW has imposed the same mass-based local limit on a number of facilities, and any categorical Standards are expressed as concentration limits or BMPs. In addition, general control mechanisms are not available for Industrial Users whose limits are based on the Combined Wastestream Formula or Net/Gross calculations, or other calculated categorical Pretreatment Standard equivalents (40 CFR 403.6(e) and 40 CFR 403.15).

How does an SIU apply for coverage under a general control mechanism?

For an individual SIU to be covered by a general control mechanism, it must file a “written request for coverage” with the POTW. Through the request for coverage, the Industrial User should identify its production processes, the types of waste generated, and the monitoring location or locations at which all regulated wastewaters will be monitored. The request for coverage should also include a finding that the SIU properly falls within the category of facilities covered by the general control mechanism. In addition, the SIU's request for coverage should include an indication of whether the User is requesting a monitoring waiver for pollutants not present.

The POTW does not necessarily need to establish an entirely new application process for SIUs seeking coverage under a general control mechanism. Existing procedures or forms may be used to provide coverage. The POTW may find that it is necessary to supplement existing procedures or forms to add the information EPA recommends for inclusion in the requests for coverage, as discussed in the preceding paragraph.

How does the POTW adopt general control mechanisms?

A POTW must have the necessary legal authority if it wants to issue general control mechanisms. Legal authority changes would include the adoption of ordinance language consistent with today's changes to 40 CFR 403.8(f)(1)(iii) and the development of any policies or procedures that would support the issuance and implementation of general control mechanisms. Refer to Section VI for a more detailed discussion of Program modifications.

In addition, general control mechanisms have to be enforceable to the same extent as an individual control mechanism. The POTW should also have enforcement authority to take action against Industrial Users that fail to file the required request for a general control mechanism, i.e., an IU that fails to file is subject to enforcement for discharging without authorization.

The POTW should develop the general control mechanism and provide notice that it is available. The general control mechanism should, of course, specify exactly what characteristics or conditions make an Industrial User eligible for coverage. The general control mechanism must also impose all of the conditions of individual control mechanisms listed in 40 CFR 403.8(f)(1)(iii)(B)(

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6

).

A POTW may make coverage by the general control mechanism mandatory or optional. In either case, if an Industrial User is to be covered by the general control mechanism, it must file the written request for coverage to be covered by the general control mechanism. The POTW should consider how it will notify SIUs, subsequent to their filing a written request for coverage, that they are authorized to discharge under the general control mechanism, including how it will memorialize certain facility-specific factors such as sampling location. EPA

notes that the POTW's annual report should indicate which SIUs are covered by each general permit.

Today's final rule does not preclude POTWs from requiring individual control mechanisms for specific Industrial Users, even if they might otherwise satisfy the conditions for a general control mechanism, where necessary or otherwise determined to be appropriate by the POTW. Today's final rule also does not restrict POTWs' existing authority to use general control mechanisms to regulate facilities that are not considered Significant Industrial Users.

What significant changes were made to the proposed rule?

Today's rule makes the following changes to the proposed rule:

Criteria for Coverage:

In proposing the criteria for coverage under a general control mechanism, EPA omitted one of the criterion used in the NPDES general permit requirements. In today's final rule, EPA is adding this criterion, which is similar to 40 CFR 122.28(a)(2)(i)(E), to the list of criteria for coverage. The following language is included in 40 CFR 403.8(f)(1)(A)(5): “in the opinion of the POTW, [the SIUs] are more appropriately controlled under a general control mechanism than under individual control mechanisms.”

Request for Coverage:

EPA has deleted all references to the requirement to submit a “Notice of Intent” (NOI) to be covered under a general control mechanism. The NOI is an instrument that is applicable to the NPDES general permit program. Although the proposal indicated that an alternative instrument could be used by the POTW, EPA has concluded that the “written request for coverage” better reflects the Agency's intention not to restrict the POTW's decision about the type of application it chooses to use in covering SIUs with a general control mechanism.

Coverage for SIUs with Monitoring Waivers for Pollutants Not Present:

EPA makes coverage under a general control mechanism available for SIUs which are requesting monitoring waivers for pollutants neither present nor expected to be present. The proposal did not state whether such facilities could still meet the required criteria for being considered substantially similar. EPA also specifies that the monitoring waiver is effective in the general control mechanism only after the SIU obtains written approval from the POTW that the monitoring waiver request has been approved.

Coverage for SIUs with Mass Limits:

The proposed rule excluded all facilities subject to mass limits from coverage under a general control mechanism. Today's final rule provides one exception to that exclusion. EPA clarifies in 40 CFR 403.8(f)(1)(iii)(A) that general control mechanisms are unavailable for facilities subject to categorical Standards expressed as mass of pollutant discharged. This language does not prevent a POTW from using a general control mechanism for a group of SIUs that all have the same mass-based local limits (as distinguished from mass-based categorical Standards), as long as the SIUs are not subject to categorical Standards that are mass-based. In addition, the final rule also clarifies that the mass-based categorical Standards excluded from coverage under a general control mechanism includes those limits that are expressed as mass of pollutant discharged per day or that are production-based.

Recordkeeping Requirements:

EPA is adding a requirement for the POTW to maintain for three years after the expiration of the general control mechanism, a copy of the general control mechanism itself, documentation to support the POTW's determination that the group of SIUs to be covered meets the required criteria, and copies of all related requests for coverage. This documentation will serve as a record for the POTW to support its actions in establishing the facility category and for authorizing coverage under the general control mechanism for individual facilities.

4. Summary of Major Comments and EPA Response

Is use of a general control mechanism in conflict with EPA's original intent in requiring individualized control mechanisms for SIUs?

One commenter expressed concern that using general control mechanisms would not provide the specificity of control over SIUs that the Domestic Sewage Exclusion (DSE) study (Report to Congress on the Discharge of Hazardous Wastes to Publicly Owned Treatment Works—EPA 530-SW-86-004) indicated was necessary. Today's rule provides an exception to the requirement that the POTW issue SIUs “permits or equivalent individual control mechanisms”. The commenter is correct in observing that the adoption of the requirement to issue control mechanisms to SIUs after EPA's issuance of the DSE study in 1986, was intended to provide a mechanism for the POTW to impose individualized Pretreatment requirements on SIUs. See 55 FR 30105-30110 (July 24, 1990). However, EPA has now concluded that general control mechanisms can provide an equivalent level of control for facilities that meet all of the requirements in 40 CFR 403.8(f)(1)(iii)(1-6), and will not lessen the POTW's enforcement capabilities.

Use of a general control mechanism does not relieve the POTW of any of its oversight or implementation requirements under its Pretreatment program. The purpose of the general control mechanism is to streamline the administrative requirements associated with issuing control mechanisms to multiple Industrial Users that are substantially similar. The level of control over an SIU with a general control mechanism should not be any different than if that User were covered by an individual control mechanism. Both individual and general control mechanisms must be enforceable and must contain the minimum conditions provided in 40 CFR 403.8(f)(1)(iii)(B)(1-6). In addition, EPA notes that it is within the POTW's discretion to exclude particular Industrial Users from general control mechanisms in order to treat those dischargers with more individually tailored requirements. EPA's intent is to leave these case-by-case determinations to the POTW, which should be in the best position to determine whether it is appropriate to use a general control mechanism for a particular User.

Is a Notice of Intent (NOI) required for an SIU requesting coverage under a general control mechanism?

Several commenters found EPA's use of the term “Notice of Intent” (NOI) problematic because it suggested that POTWs would be required to use such an instrument. These commenters requested that EPA delete the reference to NOI or make it clear that the POTW can choose the appropriate mechanism for SIUs to use in seeking coverage under a general control mechanism. EPA acknowledges these concerns, and has removed the reference to “notice of intent” in today's final rule. The revised rule instead refers only to a “written request for coverage.” The decision regarding the type of application to use for general control mechanisms is entirely the POTW's. EPA emphasizes, however, that regardless of the type of instrument chosen, the request for coverage must identify, at a minimum, the information required under new 40 CFR 403.8(f)(1)(iii)(A). POTWs must also request basic contact information (e.g., contact name, address, phone number, etc.) and specification of the general control mechanism category for which the SIU is seeking coverage. See 40 CFR 403.8(f)(1)(iii)(A). The POTW will need to obtain sufficient information to verify that the User is appropriately classified under the general control mechanism, such as

information to determine the applicability of categorical Standards.

Should there be additional criteria for a User to be eligible for coverage under a general control mechanism?

One commenter requested that EPA include additional criteria for determining whether a group of Users are substantially similar enough to merit use of a general control mechanism. The criteria included in the proposal (e.g., that facilities to be covered involve the same or substantially similar types of operations, discharge the same types of wastes, require the same effluent limitations, and require the same or similar monitoring) are taken from the criteria used for general permits for direct dischargers in 40 CFR 122.28(a)(2)(i). The direct Discharge criteria contain one additional limitation, not included in the proposal, requiring the NPDES permitting authority to document that, in his or her opinion, the dischargers “are more appropriately controlled under a general permit than under individual permits.” See 40 CFR 122.28(a)(2)(i)(E). In consideration of the commenter's request, and to be consistent with the criteria used for grouping direct dischargers within general permits, EPA has modified the proposed list of criteria to include a similar requirement that the POTW document why it believes that its SIUs are more appropriately regulated by a general control mechanism. EPA does not expect that this added criterion will impose additional burden on the POTW. This criterion merely requires that the POTW provide some written record of why it believes a particular grouping of SIUs is substantially similar, using the criteria in 40 CFR 403.8(f)(1)(iii)(A)(1-5).

Another commenter suggested that an SIU's compliance record should be used as an additional criterion for determining whether to allow general control mechanism coverage for a facility. EPA agrees that there will be factors, outside of the criteria in 40 CFR 403.8(f)(1)(iii)(A), which may support a POTW's decision to exclude a particular Industrial User from general control mechanism coverage. EPA also agrees that the need to impose a compliance schedule or enforcement order on a particular Industrial User is a good example of an additional criterion that the POTW may use to exclude an SIU from general control mechanism coverage. EPA notes that the criteria listed in 40 CFR 403.8(f)(1)(iii)(A) are minimum requirements. The POTW may include additional criteria if it chooses. However, EPA is reluctant to add additional criteria at this time, as the Agency has concluded that many of these factors will be site-specific and are best left to the POTW to judge whether they are appropriate for use in their program.

One commenter suggested that general control mechanisms not be available for SIUs that have multiple sampling locations, are subject to more than one categorical Standard, or have both federal categorical and non-categorical wastestreams. EPA agrees that situations such as this make it difficult to use a general control mechanism in some cases. However, EPA declines to adopt the additional criteria suggested by the commenter. The minimum required criteria in 40 CFR 403.8(f)(1)(iii)(A) provide some flexibility regarding the availability of coverage for any particular User. EPA prefers to leave to the POTW the site-specific judgments as to whether a class of dischargers meets the substantially similar criteria. The POTW may determine that a User which has multiple sampling points or which is subject to both categorical Standards and non-categorical requirements is sufficiently dissimilar from other Users to justify precluding that discharger from general control mechanism coverage. There may be some instances where these differences may still be accommodated under a general control mechanism, and therefore EPA has concluded that eliminating this flexibility is inappropriate.

Additionally, a general control mechanism may still be used to cover a class of Users subject to more than one categorical Standard as long as they are covered by the same Standards, in addition to meeting all other criteria for coverage. This is consistent with the requirement that all Users share the same effluent limits. See 40 CFR 403.8(f)(1)(iii)(A)(

3

). However, EPA expects that where there is one User in the class which is subject to at least one different categorical Standard than the others, even if it has one or more categorical Standards in common with the other Users, such a User would be unable to obtain coverage under a general control mechanism covering the other Users due to the differences in effluent limits.

Must the SIUs be exactly the same to be covered under a general control mechanism?

Several commenters questioned EPA's intentions behind requiring that facilities meet the “substantially similar” criteria in order to qualify for use of a general control mechanism. Some of these commenters were concerned that the criteria would be interpreted too restrictively, and that industries would essentially have to be identical to be included in a general control mechanism group. One commenter believed that industries which are similar in many respects, but which are different in terms of operations and wastewater Discharges, should not be excluded from coverage.

EPA's view is that the criteria for inclusion in a general control mechanism category are appropriate as stated. The opportunity to develop and issue the same control mechanism for multiple SIUs comes with the tradeoff that these industries share certain minimum characteristics. In response to the commenter's observation that general control mechanisms should be available for industries which are similar in many respects, but different in terms of operations and wastes discharged, EPA agrees and notes that the criteria require that the operations be “the same or substantially similar” and the Discharge be of “the same types of wastes.” EPA does not intend for these criteria to be interpreted as requiring the operations and wastes discharged to be exactly the same; rather, the intent is that industries covered under the same control mechanism be substantially similar.

EPA acknowledges that industries are rarely the same in every respect. In order for an SIU to be included in a general control mechanism category, it must meet the criteria in 40 CFR 403.8(f)(1)(iii)(A). With the exception of the SIU's effluent limits, which must be the same as other SIUs in the general control mechanism category, EPA does not expect each SIU in a general control mechanism category to be identical.

Can a general control mechanism be used for facilities which obtain a monitoring waiver for pollutants neither present nor expected to be present?

One commenter recommended that general control mechanisms not be made available for SIUs which receive a monitoring waiver for pollutants neither present nor expected to be present at the facility. The commenter reasoned that such facilities require individual control mechanisms due to the variation in sampling requirements from other facilities. EPA disagrees with the commenter. Categorical Industrial Users (CIUs) that qualify for a sampling waiver for pollutants neither present nor expected to be present can still be accommodated under a general control mechanism even if other Users in the same general control mechanism category are still required to sample for all pollutants. There is flexibility inherent in the criterion requiring all industries covered by a general control mechanism to be subject to the “same or similar monitoring”. If a particular CIU

is similar in every other respect to other CIUs, except for a sampling waiver for pollutants neither present nor expected to be present, it is EPA's view that a general control mechanism may still be used to cover this discharger. However, a POTW could choose as a matter of its own discretion to exclude CIUs with sampling waivers from coverage under the general control mechanism.

To assist the POTW in coordinating the implementation of general control mechanisms and processing requests for monitoring waivers, EPA is requiring Users to include in their requests for general control mechanism coverage any sampling waiver requests. Such a requirement will ensure that the POTW is able to process both the sampling waiver request and the general control mechanism application simultaneously, and provide the POTW with sufficient opportunity to determine what type of control mechanism is most appropriate. Where the POTW chooses to still cover those CIUs which receive monitoring waivers under a general control mechanism, 40 CFR 403.8(f)(1)(iii)(A) specifies that the monitoring waiver is effective only after the POTW has specifically notified the affected CIUs. Also, because all control mechanisms must include SIU self-monitoring requirements, unless all of the monitoring requirements and waivers for all pollutants are the same, the POTW will need to establish a common set of monitoring requirements in a general control mechanism and determine what mechanism it will use to incorporate site-specific monitoring waivers into a general control mechanism. Some possible mechanisms for addressing facility-specific monitoring waivers include issuing a separate monitoring supplement to the general control mechanism for individual CIUs, using the waiver approval notice as a site-specific modification to the general control mechanism, or appending the general control mechanism with specific monitoring waivers. See Section III.A. for discussion of requirements associated with monitoring waivers.

Can an SIU opt out of an existing general control mechanism?

Several commenters expressed opinions on one side or the other in terms of whether general control mechanisms can be made mandatory or optional by the POTW. Industrial facilities generally commented that EPA should prevent POTWs from making general control mechanisms mandatory, while POTW commenters supported keeping this decision a matter of the local program's discretion. EPA is sensitive to the concerns regarding the need for flexibility on the type of control mechanism used for individual SIUs. The industry commenters argue that the SIU should be able to choose whether it wants to be covered by an individual or general control mechanism. EPA does not specify in today's rule whether the use of general control mechanisms should be optional or mandatory. However, provided that the SIUs in a category meet the required criteria, the POTW has the discretion to determine whether coverage under the general control mechanism is required or whether the Industrial User will have the option of being covered under an individual control mechanism. EPA emphasizes that there should be minimal if any difference between an individual and general control mechanism since the POTW is required to include in a general control mechanism all of the conditions of individual control mechanism listed in 40 CFR 403.8(f)(1)(iii)(B)(

1

)-(

6

). Even if the POTW chooses to make general control mechanism coverage mandatory, the SIU may be able to demonstrate to the POTW that it does not meet one of the criteria and therefore should be issued an individual control mechanism.

C. Best Management Practices (40 CFR 403.5, 403.8(f) and 403.12(b), (e), and (h))

Today's final rule clarifies that Best Management Practices (BMPs) may be used in lieu of numeric local limits. EPA also clarifies the reporting requirements that apply when BMPs are used as Pretreatment Standards.

1. What are the existing rules?

What are Best Management Practices?

Best Management Practices (BMPs) are management and operational procedures that are intended to prevent pollutants from entering a facility's wastestream or from reaching a Discharge point. BMPs are distinguished from numeric effluent limits that regulate the pollutants once they enter a wastestream. Although the General Pretreatment Regulations have not previously defined BMPs, the NPDES regulations at 40 CFR 122.2 define BMPs as schedules of activities, prohibitions of practices, maintenance procedures, and other management practices to prevent or reduce pollution. BMPs also include treatment requirements, operating procedures, and practices to control plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw material storage.

There are two different circumstances in which BMPs may be Pretreatment Standards. The first is when a POTW establishes BMPs as local limits to implement the general and specific prohibitions. The second is when the BMPs are categorical Pretreatment Standards established by EPA.

What regulations address the use of BMPs as local limits?

Prior to today's rule, the Pretreatment Regulations did not specifically address the use of BMPs as local limits. Thus, 40 CFR 403.5(c) required POTWs to develop “specific limits” and “specific effluent limits”, without defining the term “limits.” (emphasis added)

The Local Limits Development Guidance (EPA 833-R-04-002A, July 2004) includes a discussion in support of BMPs as local limits, and provides references and case studies to illustrate situations where BMPs have been utilized. EPA indicates also that the development and implementation of numeric local limits is not always the only appropriate or practical method for preventing pollutant Pass Through and Interference, or for protecting POTW worker health and safety. For instance, control of chemical spills and Slug Discharges to the POTW through formal chemical or waste management plans can go a long way toward preventing problems. A local requirement for an Industrial User to develop and submit such a plan can be considered as a type of narrative local limit and can be a useful supplement to numeric limits.

What regulations address the use of BMPs as categorical Standards?

Certain categorical Pretreatment Standards allow the use of BMPs as an alternative means of complying with, or in place of the established numeric effluent limit. For example, facilities may develop toxic organic management plans in lieu of sampling to demonstrate compliance with the total toxic organic limit in 40 CFR Part 433 (Metal Finishing category). The Pesticides Formulating, Packaging, and Repackaging (PFPR) regulation provides a pollution prevention alternative as an option that may be chosen rather than complying with the “zero discharge” limitations. See 40 CFR Part 455 (61 FR 57518, November 6, 1996).

Although the PFPR and some other categorical Standard regulations have provided for reporting compliance data related to BMPs, the Part 403 Pretreatment Regulations did not. See 40 CFR 403.12(b), (d), and (e). Those requirements focused on sampling data to demonstrate compliance with numeric limits rather than

documentation to determine compliance with a BMP.

2. What changes did EPA propose?

EPA proposed to clarify the regulations to provide specifically that BMPs developed by POTWs may serve as local limits required by 40 CFR 403.5(c)(3). The BMPs would be enforceable under 40 CFR 403.5(d). They would be included as local control mechanism requirements under 40 CFR 403.8(f)(1)(iii)(C).

EPA also proposed to modify 40 CFR 403.12(b), (e), and (h) to clarify the reporting requirements that apply when BMPs are used as Pretreatment Standards. This would include any documentation required by the Control Authority or the Standards themselves to demonstrate compliance with BMPs that are included in categorical Standards, as well as any documentation required by the Control Authority to demonstrate compliance with BMPs that serve as local limits. EPA also proposed a change to the definition of significant noncompliance (SNC) to facilitate POTW oversight of these practices. The proposal would broaden the SNC definition at 40 CFR 403.8(f)(2)(vii)(C) to include non-numeric violations such as BMPs. In addition, EPA proposed to revise the reference to “pretreatment effluent limit”, and replace it with the more inclusive reference to “Pretreatment Standard or Requirement”.

3. What changes is EPA adopting today?

Today's rule adopts the proposed rule changes to the Pretreatment Regulations relating to the use of BMPs as local limits, and the reporting requirements when BMPs are used as national categorical Standards.

What significant changes were made to the proposed rule?

The only significant change made to the proposed rule was the inclusion in 40 CFR 403.3(e) of a definition of BMPs consistent with the NPDES definition.

4. Summary of Major Comments and EPA Response

Does the CWA authorize POTWs to require implementation of BMPs as local limits?

A few commenters questioned the authority under the CWA for POTWs unilaterally to require Industrial Users to implement BMPs instead of or in addition to numeric local limits. POTW authority to establish limits and other controls on Discharge derives from state law, not the CWA. The Act, together with the Pretreatment Regulations, specifies authorities that POTWs must have, and establishes the conditions under which local requirements become federally enforceable. There is nothing under the Act that would preclude POTWs from setting BMP-based limits, or EPA from making such limits established by a POTW federally enforceable.

How are BMPs defined?

Several commenters felt that the use of the NPDES definition of BMPs would be appropriate in the Pretreatment context. EPA agrees that such a definition would be useful, and is adopting the NPDES definition, modified slightly to reference relevant Pretreatment Standards.

Is a regulatory change needed for BMPs developed by POTWs to be considered enforceable local limits?

Some commenters expressed the view that BMPs could already serve as enforceable local limits, and that a regulatory change was unnecessary. As discussed in the preamble to the proposal, the existing regulations do not specifically address this issue, although EPA has supported their use in its local limits guidance. EPA has concluded that revision of the regulations is necessary to clear up any questions on this issue. As will be discussed below, by providing this clarification EPA is ensuring that POTWs have additional means at their disposal as they seek to control pollutants and sources not amenable to more traditional numeric limits.

Will POTWs be limited in their ability to develop BMPs as local limits?

Some commenters recommended that the POTW's ability to use BMPs as local limits be limited to certain situations, such as where it is impracticable to obtain representative sampling data from a type of discharger, the Discharge flow is minimal or variable, or where operations or processes of a type of discharger are similar enough that effective BMPs can be established. In general, EPA anticipates that POTWs will choose to use BMPs instead of numeric local limits where determination of compliance with numeric limits is infeasible, or as a supplement to numeric limits as appropriate to meet the requirements of the CWA. As the commenters pointed out, BMPs may be appropriate for regulating releases when the types of pollutants vary greatly over time, when chemical analyses are impracticable, and when other Discharge control options are inappropriate. It may also be appropriate for IUs to be required to comply with both BMPs and numeric limits. While use of BMPs is not appropriate in all situations, their use, either in conjunction with or instead of numeric limits, will be at the discretion of the POTW, with oversight by EPA and the state Approval Authority.

What are some specific situations where BMPs would be appropriate?

Numerous commenters representing POTWs, Industrial Users and trade associations provided specific examples where BMPs would be well-suited to address certain types of industrial or commercial Discharges, either in lieu of or in addition to numeric local limits. Examples involving requirements for photoprocessors to use silver recovery systems and/or management practices were frequently cited to address silver Discharges from large numbers of commercial facilities. Also cited were requirements for dental facilities to follow BMPs to control mercury Discharges from dental amalgam where individual monitoring on a large scale is impractical and where Discharges are episodic in nature. Similarly, other commenters referred to use of shop towel management and other BMPs to address Discharges from printing facilities, or setting requirements for “no Discharge” of tetrachloroethene from dry cleaning facilities as an alternative to complying with a numeric limit. The Agency agrees that these are good examples of situations where BMPs may be appropriate.

BMPs may also be used to supplement categorical Standards or numeric local limits at larger facilities. One commenter described the use of chemical management plans to address specific pollutants in individual IU Permits. These plans, which were required by the POTW, require IUs to identify within 60 days of Permit issuance all sources of a given pollutant within the plant site; specify actions to be taken to control these identified sources; provide a schedule for implementing the plan; and identify individuals responsible for implementation of the plan. Upon approval by the POTW, the chemical management plan is incorporated into the IU's Permit as an enforceable requirement.

Who decides whether a POTW will require an IU to comply with a BMP or numeric limit?

Some industries and trade associations asked EPA to ensure that IUs have the option of whether to meet BMPs or numeric limits. While POTWs are encouraged to work with affected Users in developing local limits, and must comply with applicable public participation requirements, the POTW is responsible for developing, implementing and enforcing local limits as it deems appropriate to meet its program requirements. As discussed above, whether BMPs are used in conjunction with or instead of numeric

limits will be at the discretion of the POTW, upon approval by the Approval Authority.

How are BMPs factored into the technical evaluation of local limits?

The preamble to the proposed rule stated that for BMPs to be considered local limits under 40 CFR 403.5(c), the practices must protect against Pass Through and/or Interference. This will require the POTW to evaluate the BMPs during the technical evaluation of its local limits. Some commenters raised questions regarding whether a POTW would need to quantify the effects of a BMP in its calculation of its maximum allowable industrial loading (MAIL), and if so, how that should be done.

As discussed in the preamble to the proposal, BMPs are expected to be used where calculation of numeric effluent limitations is not feasible, such as when the types of pollutants vary over time or when chemical analyses are inappropriate. Nevertheless, a POTW needs to assign an allocation of pollutants to Users covered by the BMP either in its calculation of Maximum Allowable Industrial Loadings (MAIL), or in calculation of separate allowable loadings for commercial facilities. For instance, a POTW could estimate the loading of a pollutant from a given sector prior to imposition of BMPs by multiplying the average loading per User by the number of facilities. Expected loading reductions from required BMPs could then be estimated and incorporated into the MAIL. Thus, the POTW should be able to provide an evaluation that implementation of the numeric limit plus implementation of BMPs for specific sectors will result in the calculated Maximum Allowable Headworks Loading (MAHL) being met. Where it is expected to take a significant amount of time for BMP-based reductions to be realized, the Apre-BMP” loading from the sector should be used in the MAIL calculations. Initial estimates of loading reductions could then be verified through sampling of selected Users that have implemented the BMPs or evaluating influent loadings for pollutants being addressed by BMPs to see if adjustments are needed for the allowable headworks loadings, the numeric limits or BMPs for any affected sectors.

May States and EPA Regions establish BMPs as local limits?

One commenter observed that the language in 40 CFR 403.5(c)(4), allowing POTWs to develop BMPs as local limits, would not pertain to states that administer authorized Pretreatment programs. The commenter supported broadening this language to allow authorized states and Regions, acting in their capacity as Control Authorities, to develop and enforce BMPs. Section 40 CFR 403.5(d), states that “where specific prohibitions or limits on pollutants (i.e., local limits) are developed by a POTW in accordance with (40 CFR 403.5(c)), such limits shall be deemed Pretreatment Standards for the purposes of section 307(d) of the Act.”

An authorized state which does not approve POTW programs but assumes local responsibility by acting as the Control Authority under 40 CFR 403.10(e) is required to implement all elements of the Pretreatment program established for POTWs in 40 CFR 403.8(f), including the establishment of local limits (40 CFR 403.8(f)(4)). Local numeric limits or BMPs established in this situation would be federally enforceable Pretreatment Standards under 40 CFR 403.5(d) provided such limits are authorized by state law.

An authorized state acting as the Approval Authority, and as Control Authority for Industrial Users which discharge to a POTW without an approved program, may develop and implement BMPs or other local limits applicable to those Industrial Users provided such limits are authorized by state law. In the case where EPA acts as the Approval Authority and Control Authority, for a local limit to be federally enforceable under 40 CFR 403.5(d), the limit would need to be incorporated into the local POTW's sewer use ordinance or other legal authority.

What are some of the common elements of an enforceable BMP?

Many commenters expressed the view that without additional guidance on the structure of BMPs, their use could be subjective and difficult to evaluate or enforce. Others felt that because of their subjective and potentially arbitrary nature, BMPs should not be allowed to serve as local limits. BMPs developed by a POTW to protect against Pass Through and Interference can be structured in such a manner that compliance with their terms can be verified by a POTW, and can provide a useful alternative to numeric limits in situations where such limits are infeasible or impractical. In addition, BMPs established by POTWs as local limits will be subject to oversight from the POTW's state and EPA Region. These BMPs will be evaluated by states and EPA based on factors such as legal authority, effectiveness, and enforceability.

Based on EPA's experience and observations of situations where BMPs have been effective, enforceable BMPs should generally include the following elements. Depending on the sector being controlled, however, certain elements such as installation of treatment or prohibitions on practices may not be applicable.

•

Specific notice to IUs of requirements and enforceability.

This notice, provided through POTW sewer use ordinances or individual or general control mechanisms, should make clear which Users are subject to the BMPs, and what affected Users must do to comply with their requirements.

•

Installation of treatment.

POTWs should provide criteria or specifications that the equipment must satisfy. For example, a requirement for use of oil/water separators at auto repair facilities could include sizing or design criteria. EPA cautions POTWs to avoid endorsing the use of specific brands or vendors.

•

Requirements for or prohibitions on certain practices, activities or Discharges.

POTWs should include specific requirements or prohibitions where necessary to ensure that the use of such BMPs is protective. An example would be a prohibition on Discharges of tetrachloroethene from dry cleaning facilities.

•

Requirements for operation and maintenance (O&M) of treatment units.

POTWs should spell out their O&M expectations to ensure that treatment systems continue to perform as designed and installed. For example, restaurants could be required to have grease interceptors cleaned out at a specified frequency.

•

Timeframes associated with key activities.

POTWs should provide timeframes for when management practices must be implemented, or when required treatment must be installed and fully operational. Other milestones should be added to the schedule where necessary to facilitate the oversight of BMP implementation.

•

Compliance certification, reporting and records retention.

Establishing specific procedures for such requirements will enable POTWs to verify whether required equipment has been installed, or whether required maintenance has been performed at the specified frequency.

•

Provision for re-opening or revoking the BMP conditions.

As with numeric limits, POTWs should include language in the sewer use ordinance and/or facility control mechanisms that enables them to revoke the control mechanism at any time to include modified numeric limits or BMPs. For example, the POTW may find it necessary to revoke an Industrial User's control mechanism where the POTW determines that the User has not complied with applicable BMPs, or where the POTW determines

that it is easier to determine compliance with a numeric limit.

•

Other requirements as determined by the POTW.

What local legal authority changes will be necessary?

POTWs wishing to establish BMPs instead of or in addition to numeric local limits will need to evaluate their sewer use ordinances to ensure they provide adequate authority to require compliance with BMPs by affected Users. Further, BMP requirements such as those discussed above, and which IUs they cover, should be specified in POTW sewer use ordinances and/or Industrial User control mechanisms.

How will compliance and significant noncompliance be determined?

Concerns were expressed regarding the ability of Control and Approval Authorities to determine whether a User is in compliance with BMPs. In EPA's view, BMPs that set specific requirements, incorporating as appropriate the common elements presented above, (i.e., requirements or prohibitions on practices, activities or Discharges; requirements for installation, operation and maintenance of treatment units; timeframes for key activities; reporting and records retention; certification and reporting of compliance, etc.) will aid POTWs and Approval Authorities in their compliance determinations. Once these requirements are established for one or more facilities in a sector, an IU's compliance status should be able to be verified through a combination of self-reporting and verification inspections. Where a facility subject to BMPs has not satisfied the requirements in the sewer use ordinance or control mechanism, the POTW would need to use its enforcement response plan (ERP) to determine the appropriate response, and relevant significant noncompliance criteria to assess whether the facility is in significant noncompliance. For example, a facility that fails to install required treatment equipment within a specified timeframe would generally be viewed as being in significant noncompliance 90 days after the schedule date. See 40 CFR 403.8(f)(2)(vii)(E). Likewise, a facility would be in significant noncompliance if it failed to submit a compliance certification within 45 days from the due date. See 40 CFR 403.8(f)(2)(vii)(F). POTWs adopting BMPs as local limits, or that have Categorical Industrial Users whose categorical Standards include BMPs, should evaluate their ERPs to ensure that they reflect the need to enforce non-numeric requirements.

D. Slug Control Plans (40 CFR 403.8(f)(1)(iii)(B)(6) and 403.8(f)(2)(vi))

Today's final rule addresses the requirement that POTWs evaluate the need for a slug control plan for SIUs every two years. The rule will provide POTWs with the flexibility to determine how frequently to evaluate the need for such plans, based on local conditions. At the same time, the new rule specifies that an evaluation must be undertaken for each SIU once within a specified timeframe. Today's rule also clarifies that an actual slug control plan (e.g., the physical document itself) is not the POTW's only option for controlling facilities with a higher potential for Slug Discharges. The regulation states that the POTW may choose to require that the SIU take specific, preventative actions instead of requiring the development of a slug control plan. Regardless of the requirements imposed by the POTW, today's rule will require that where actions to control Slug Discharges are determined to be necessary, the SIU's control mechanism must include provisions addressing those requirements.

These revisions do not alter current requirements regarding annual monitoring and inspections of SIUs. POTWs are still required to conduct their annual facility inspections and effluent monitoring for each of their SIUs. The revisions also do not change the POTW's requirement to prevent disruptions caused by Slug Discharges. EPA expects that, as an integral part of its ongoing oversight of all SIU facilities, the POTW will consider whether adequate measures are in place to avoid Slug Discharges. The POTW is authorized to use its own discretion in determining the timing, level of detail, and commitment of resources necessary to ensure the facility has adequate measures in place to protect against Slug Discharges. POTWs may still require the SIU to develop a slug control plan or take specified preventative measures to prevent Slug Discharges whenever the facility's slug control measures are judged to be inadequate.

Today's rule does not impose any new requirements on Industrial Users. SIUs remain subject to current requirements to eliminate or mitigate the effects of a Slug Discharge. These actions may include constructing physical containment facilities as well as implementing sound management practices to prevent Slug Discharges.

1. What were the rules in place prior to today's rulemaking?

A Slug Discharge is defined as “* * * any Discharge of a non-routine, episodic nature, including but not limited to an accidental spill or non-customary batch Discharge” (40 CFR 403.8(f)(2)(v)). EPA notes that the subparagraph numbers have changed slightly in the final rule due to other, unrelated modifications. The appropriate rule reference is now 40 CFR 403.8(f)(2)(vi). The regulations require POTWs to ensure that Industrial Users have policies and procedures in place to prevent or mitigate the effects of Slug Discharges. Section 40 CFR 403.8(f)(2)(v), prior to today's rulemaking, required POTWs to “* * * evaluate, at least once every two years, whether each such Significant Industrial User needs a plan to control Slug Discharges.” The function of such a plan is to ensure that an SIU has a planning and implementation tool to prevent Interference at a POTW treatment facility by a non-routine or accidental Discharge. The minimum elements required in a slug control plan are (1) a description of Discharge practices, (2) a description of all stored chemicals at the facility, (3) procedures for immediately notifying the POTW of the Slug Discharge and providing written follow-up notification, and (4) a variety of procedures (e.g., inspection and maintenance of chemical storage areas) for preventing adverse impacts from any accidental spills (40 CFR 403.8(f)(2)(v)(A) to (D)).

The requirement for a once every two years review of the need for a slug control plan was part of the Domestic Sewage Study rulemaking (55 FR 30082, July 24, 1990). In the preamble discussion to that rulemaking, EPA explained the need for POTWs to implement slug control programs. As part of the discussion, EPA referenced the guidance manual,

Control of Slug Loadings to POTWs

(EPA 21W-4001, February 1991, see

http://www.epa.gov/npdes/pubs/owm021.pdf

), which was then under preparation. This manual provides detailed guidance for POTWs to evaluate whether SIUs need to develop slug control plans. It also provides guidance for SIUs in developing those slug control plans. In addition, the manual recognizes that POTWs need to determine whether existing on-site conditions may impact their treatment works, while industries are in the best position to solve problems relative to their physical plants or production processes. Part 403 requires that, where found to be necessary, a POTW must require an SIU to develop a plan or impose some specified control actions to prevent Slug Discharges.

2. What changes did EPA propose?

The proposed rule suggested eliminating the requirement that POTWs evaluate the need for a slug control plan for each SIU every two years. Instead, EPA proposed giving POTWs the flexibility to review the need for slug control plans or other actions as part of their ongoing oversight of Industrial Users. The proposal would have added language to clarify that requiring an actual slug control plan is one of several options the POTW has at its disposal for controlling facilities with a higher potential for Slug Discharges. The proposed rule would have clarified that a POTW could choose to require that the SIU take certain specified preventative actions to control the Slug Discharge potential, instead of developing a slug control plan. In addition, to ensure that slug controls are enforceable to the same extent as other Standards and requirements, the proposal would have added language to require that, where a slug control plan or other action is found to be necessary, appropriate requirements would be placed in the Industrial User's control mechanism.

3. What changes is EPA finalizing in today's rule?

In today's final rule, consistent with the proposal, EPA removes the required minimum frequency for conducting POTW evaluations for the need for slug control plans or other control actions. The final rule also formalizes the requirement for SIUs to address Slug Discharges by requiring that the POTW include language in the User's control mechanism to control Slug Discharges, if it determines that a slug control plan or other action is necessary. These rule revisions appear in 40 CFR 403.8(f)(1)(iii)(F) and 403.8(f)(2)(vi).

What significant changes were made to the proposed rule?

Today's rule makes the following changes to the proposed rule:

Minimum evaluation frequency:

Today's rule specifies that POTWs must evaluate at least once the SIU's need for a slug control plan or other action to control Slug Discharges. See 40 CFR 403.8(f)(2)(vi). While the POTW may choose how frequently to assess slug-related concerns, it is EPA's view that it is important to impose a minimum frequency of one time per SIU to ensure that each SIU receives at least one thorough evaluation. The provision specifies that this evaluation must have occurred within one year of the effective date of today's rule for SIUs identified as significant (yet never evaluated for the need for a slug control plan) prior to the rule's effective date. Also, SIUs identified as significant after the effective date of the rule must be evaluated for the need for a slug control plan within one year of being identified as significant.

Notification of significant facility change:

EPA also adds a requirement that SIUs must notify the POTW immediately of any changes at their facilities, not already addressed in their slug control plan or other slug control requirements, which may affect the potential for a Slug Discharge. This requirement is especially relevant in the case of those Users for which the POTW has determined, from some prior assessment, that a slug control plan or other action is unnecessary. However, EPA emphasizes that this requirement affects all SIUs, even those that already have slug control plans or other measures in place. See 40 CFR 403.8(f)(2)(vi). This provision places an affirmative duty on such Users to provide the POTW with updated information on the potential slug risks that are posed by industrial process changes. This provision is consistent with, but differs from the existing notification of changed Discharge in 40 CFR 403.12(j), which focuses on advance notice of change in the volume or character of pollutants in the Discharge itself.

4. Summary of Major Comments and EPA Response

The following summarizes the major comments received and EPA's response.

Should POTWs be required to conduct annual inspections of SIUs to determine the adequacy of slug control plans?

One commenter supported the proposed rule change, but recommended adding language to require the POTW to verify during an inspection that a slug control plan, if required, is adequate. EPA agrees with the commenter that the POTW should be assessing the adequacy of existing slug control plans during its annual inspection of SIUs. However, EPA has not included a specific requirement in the regulation to this effect since existing inspection and sampling guidance already recommend that POTWs assess the adequacy of slug control plans during the POTW's annual inspection.

EPA emphasizes that this provision does not affect the POTW's requirements to conduct inspections of its SIUs, nor has EPA changed its recommendations about how to assess slug-related issues at each facility. According to EPA's

Industrial User Inspection & Sampling Manual for POTWs

(1994) (

http://www.epa.gov/npdes/pubs/owm0025.pdf

), POTW inspectors should ask SIU staff if they are familiar with slug control procedures, and request that a copy of the slug control plan be provided for an assessment of its adequacy. EPA's guidance document

Control of Slug Loadings to POTWs

(1991) (

http://www.epa.gov/npdes/pubs/owm021.pdf

) recommends that inspectors verify compliance with slug control requirements and plans (see p. 2-44). In addition, EPA's slug loading guidance indicates that “the inspector should ascertain the Industrial User's status with regard to compliance with the Plan, report any deficiencies observed in the Industrial User's current Plan, and suggest alternatives or modifications” (see p. 2-44).

Can existing control measures or planning documents substitute for slug control plan requirements at SIU facilities?

Several commenters, while supporting the proposal, requested that EPA clarify that existing spill containment procedures or plans may adequately fulfill the Pretreatment requirements concerning slug control plans. EPA agrees with the commenter that there will be situations where existing containment and spill planning documents at an Industrial User facility describe adequate means for protection against Slug Discharges. EPA recognizes that a number of existing requirements under other statutes and regulations could serve as components of slug control plans. For example, Spill Prevention, Control, and Countermeasures (SPCC) plans may address some components of a slug control plan. A POTW could also consult existing Emergency and Hazardous Chemical Inventory reports (EPCRA Section 312, 40 CFR 370) typically submitted to local fire marshals or other Local Emergency Planning Committee offices for the facility. If an SIU is covered by any of these pre-existing plans, the POTW may accept such plans in partial or complete fulfillment of the slug control requirements, as long as each element set forth in 40 CFR 403.8(f)(2)(vi)(A)-(D) is addressed in an acceptable manner in some document or collection of documents, and a reference to the need to comply with these procedures is included in the User's control mechanism pursuant to 40 CFR 403.8(f)(1)(iii)(F). However, EPA notes that many of these pre-existing plans have been developed for purposes other than control of Slug Discharges to POTWs, and the POTW must carefully review the plans to ensure that they

meet the requirements of a slug control plan and the needs of the POTW.

In summary, under today's rule, a POTW has the discretion to determine, based on an initial inspection or previous evaluations, that existing procedures and control measures at the facility make the development of a slug control plan unnecessary. The POTW should document this finding as part of its records, and, consistent with existing EPA guidance, should annually assess the adequacy of these existing procedures and control measures as part of its annual inspections. Also, implementation of these procedures or control measures should be included as requirements in the facility's control mechanism.

How should the POTW determine how often to conduct evaluations at individual facilities concerning whether a slug control plan is needed?

One commenter pointed out that how frequently a POTW should evaluate the need for a slug control plan may vary for different facilities. The commenter emphasized that at some facilities, conducting such an evaluation once every two years may not be sufficient. Regarding the commenter's concerns about the frequency of Slug Discharge evaluations, under today's rule, each POTW will need to determine what evaluation frequency is appropriate for its program and/or for individual facilities. EPA also recommends that POTWs consult with the Agency's guidance document,

Control of Slug Loadings to POTWs

(1991) (

http://www.epa.gov/npdes/pubs/owm021.pdf

), which suggests different ways to prioritize industrial facilities according to Slug Discharge potential and strategies for assessing the adequacy of existing plans and programs. To ensure that POTWs are provided with sufficient notice of a change in Slug Discharge potential, EPA has added an additional requirement for SIUs which are not required to develop a slug control plan to notify the POTW immediately of any changes at their facilities affecting the need for plans or other actions to address Slug Discharges. It is EPA's position that placing the affirmative duty on the SIUs to notify the POTW of such changes further reduces the potential for Slug Discharge in the time between on-site inspections.

Although supporting the proposal, several commenters suggested that EPA adopt further criteria for determining when a slug control plan is necessary at an individual facility. Among the suggested criteria were the following: (1) Slugs from an industrial facility violated the Pretreatment requirements or otherwise harmed the POTW; or (2) the amount of stored materials, the absence of sufficient secondary containment, and the proximity of drains to the sewer create a significant risk of a harmful slug. EPA agrees with the commenter in general that criteria suggesting when a slug control plan should be developed would assist POTWs in making this decision. On the other hand, EPA decided that it should not develop rigid criteria in its regulation establishing when slug control plans should be required.

EPA emphasizes that a POTW is in the best position to make such determinations and, since such requirements will help ensure continued compliance with its NPDES Permit, it is in the interest of the POTW to do so. However, in lieu of providing a list of strict criteria, EPA suggests that POTWs and SIUs consult the Agency's guidance document, Control of Slug Loadings to POTWs (1991) (

http://www.epa.gov/npdes/pubs/owm021.pdf

), for recommendations on significant factors and types of industries to consider in determining which facilities pose a greater risk of Slug Discharge, and, therefore, should be required to develop a slug control plan. For instance, the guidance document highlights the following as the most significant factors to consider: Quantity and types of materials used or stored at an IU and their potential for causing violation of local limits or the general or specific prohibitions; potential for such materials to enter the sewer system and cause damage (i.e., whether control measures are in place); and adequacy of existing controls to prevent any potential slug loading (see p. 2-19). EPA points out, though, that the guidance also clarifies that these evaluations should be conducted on a plant-by-plant basis and that the list of factors and target industries provides generalizations from which to start. (see p. 2-7).

In response to the commenter's recommended criteria, EPA agrees that facilities which have had Slug Discharges, thus violating the Pretreatment Requirements or otherwise harming the POTW, will need a slug control plan. The slug control plan requirements were adopted to provide POTWs with a mechanism to prevent slug-related impacts. EPA is concerned that this criterion may suggest to POTWs that it is sufficient to wait for circumstances to arise (e.g., an instance of Interference at the treatment plant) before addressing the need for a slug control plan at a potentially higher risk facility. EPA does not agree that the only situations where an SIU should be required to develop a slug control plan are those where a violation of the POTW's Pretreatment program requirements has occurred. Part of what the POTW must evaluate at each SIU is whether there is the “reasonable potential” for Interference or Pass Through from a Slug Discharge, thereby necessitating a slug control plan or other preventative action. EPA suggests that waiting for a violation to occur before requiring a slug control plan conflicts with the proactive intent behind 40 CFR 403.8(f)(2)(vi) and may result in unnecessary Interference or Pass Through occurrences.

EPA does agree that the commenter's second suggested criterion, that the amount of stored materials, the absence of sufficient secondary containment, and the proximity of drains to the sewer create a significant risk of a harmful slug, would be appropriate POTW considerations for requiring the development of a slug control plan. These considerations are contemplated in the above referenced guidance.

How does the rule affect the current practice of evaluating SIUs annually for the adequacy of slug controls?

A few commenters were opposed to the proposal because they considered it to be unnecessary. These commenters emphasized the limited burden imposed by the current biannual review requirement and the current practice of conducting annual SIU inspections which focus on, among other things, the adequacy of controls or existing plans for addressing the potential for Slug Discharges. Another commenter objected to the proposal because of concern that POTWs would no longer dedicate the necessary attention to evaluating SIU facilities for the potential for Slug Discharges.

The evaluation of slug control procedures and measures is already occurring at POTWs on an annual basis, typically during the inspection of the SIU. This practice is consistent with EPA's guidance document, Industrial User Inspection and Sampling Manual for POTWs (1994) (

http://www.epa.gov/npdes/pubs/owm0025.pdf

). EPA's modification of the frequency of the POTW's evaluation of the necessity of slug control plans should not affect the POTW's practice of conducting annual inspections of relevant slug control procedures and measures. The final rule changes do not absolve POTWs from the requirement to prevent disruptions caused by Slug Discharges. In many instances, operating conditions at an SIU will not have changed significantly since the issuance of its individual control mechanism and the facility will be in compliance with all of its Permit conditions. Under these circumstances,

the requirement to review and evaluate the need for a slug control plan or other preventative actions could be an unproductive use of resources by the POTW. In addition, today's revision to 40 CFR 403.8(f)(2)(vi) requires that each POTW evaluate the need for a slug control plan or other action at least one time at every SIU. Following this evaluation, the POTW may determine its own schedule for conducting further evaluations for the need for a plan.

In practical terms, EPA expects POTWs to take the following actions with regard to Slug Discharges: Evaluate all of their SIUs at least once for the need for a slug control plan, conduct follow-up evaluations for facilities not required to develop a slug control plans or take other actions as necessary, and inspect each SIU annually to determine the adequacy of and compliance with existing procedures and control measures. While today's revision may reduce the administrative resources currently devoted to biannual reviews for the need for a slug control plan, the POTW's overall level of oversight over Slug Discharges will not be reduced.

EPA also points out that Approval Authority audits and Pretreatment Compliance Inspections (PCIs) of POTW Pretreatment Programs will offer a valuable opportunity to evaluate how today's revisions are being implemented. During these audits or PCIs, the POTW will need to demonstrate that each SIU has been evaluated at least once (or that there is a plan to conduct such an evaluation within the coming year). EPA suggests that where a slug control plan or other action was not deemed necessary, a plan to re-evaluate the SIU for the need for a plan or other action as necessary exists. The POTW may choose a specified frequency level to re-evaluate the SIU, or it may choose to re-evaluate the facility following a notification of changed Discharge pursuant to 40 CFR 403.12(j) or 40 CFR 403.8(f)(2)(vi). EPA notes that SIUs will now be required to notify the POTW of any changes at their facility that affect the need for a slug control plan or other actions to address Slug Discharges, although POTWs still have the responsibility during the facility inspections to ensure that these notifications have been made. In addition, during the audit or PCI, the Approval Authority should determine whether the POTW is conducting an assessment of the SIU's on-site procedures and measures to control for potential slug-related Discharges.

Does the slug control plan, if required, need to be included in the SIU's control mechanism?

One commenter was opposed to what it interpreted as EPA's requirement in 40 CFR 403.8(f)(1)(iii)(B)(

6

) to include the entire slug control plan document in the SIU's control mechanism. The commenter further emphasized that the slug control plan should be retained as a separate document, and suggested that the plan be incorporated by reference into the control mechanism requiring compliance with the approved plan.

EPA disagrees with the commenter as far as reading 40 CFR 403.8(f)(1)(iii)(B)(

6

) to require the inclusion of the entire slug control plan in the SIU's control mechanism. Section 403.8(f)(1)(iii)(B)(

6

) provides that the control mechanism must include “requirements to control Slug Discharges.” EPA expects that POTWs will include language in the control mechanism that requires control of Slug Discharges, rather than the terms of a particular SIU's plan. Including the entire slug control plan may prove to be administratively burdensome since changes made to the plan during the term of the control mechanism would potentially require that the control mechanism be modified, or be reopened and reissued.

E. Equivalent Concentration Limits for Flow-Based Standards (40 CFR 403.6(c)(6))

Today's amendment to the Pretreatment Regulations authorizes the use of concentration-based limits in lieu of flow-based mass limits for the facilities in the Organic Chemicals, Plastics, and Synthetic Fibers (OCPSF) (40 CFR part 414), Petroleum Refining (40 CFR part 419), and Pesticide Chemicals (40 CFR part 455) categories. The Control Authority may use the concentration limits listed in the categorical Pretreatment Standards for these three categories as an alternative to the current requirement to convert those concentration limits to flow-based mass limits. Control Authorities establishing concentration-based Pretreatment Standards instead of mass-based limits must document that dilution is not being used as a substitute for treatment (

see

§§ 403.6(d), 414.111(a), 419, and 455). Additionally, the Control Authority is required to adjust Permit limits using the combined wastestream formula in § 403.6(e) when the wastestream used for demonstrating compliance with the Permit limits is mixed with non-process wastewater or wastewater from other processes.

1. What are the current rules?

What is a flow-based mass limit?

National categorical Pretreatment Standards establish limits on pollutants discharged to POTWs by specific industrial sectors. The Standards establish limitations on the amount of pollutants to be discharged by individual dischargers in different ways for different categories. The regulations establishing Pretreatment Standards for new and existing indirect dischargers in the Organic Chemicals, Plastics, and Synthetic Fibers Category (OCPSF), for new indirect dischargers in the Petroleum Refining category, and for new and existing indirect dischargers in the Pesticide Chemicals category currently require limits of certain pollutants to be expressed in terms of mass, based on the promulgated concentrated-based Standards and the average daily flow rate of the Industrial User's regulated process wastewater (

see

§§ 414.111(a), 419.17(b), 419.27(b), 419.37(b), 419.47(b), and 419.57(b), 455.26, 455.27). For an OCPSF indirect discharger, a pesticide chemicals indirect discharger, or a new petroleum refining indirect discharger, the Control Authority develops a mass limit by multiplying the applicable pollutant concentration that EPA promulgated in the effluent guidelines (expressed in terms of mass of pollutant per volume of Discharge) by the average daily flow rate of the Industrial User's regulated process wastewater (expressed in terms of volume per day). The result is a Permit limit on the mass of pollutants per day (

see

58 FR 36890, July 9, 1993).

The average daily flow rate should be based upon a reasonable measure of the Industrial User's average daily flow for at least a 30-day period (

see

40 CFR 403.6(e)(1)). Additionally, EPA “strongly urges the Control Authority to develop an appropriate process wastewater flow for use in computing the mass effluent or internal plant limitations based on water conservation practices,” (

see

58 FR 36890, July 9, 1993). Finally, a Permit may be modified during its term, either at the request of the permittee (or another interested party) or on the Control Authority's initiative, to increase or decrease the flow basis in response to a significant change in production (40 CFR 124.5, 122.62). A change in production could be an “alteration” of the permitted activity or “new information” that would provide the basis for a Permit modification (40 CFR 122.62(a)(1),(2)) (

see

58 FR 36891, July 9, 1993).

Why was the mass limit approach developed?

Effluent guidelines may be specified in a number of ways including production normalized (mass-pollutant/production unit) and concentration-

based limitations (mass-pollutant/volume of wastewater). These two types of effluent guidelines limits can be converted to a mass-based Standard by using a reasonable measure of the Industrial User's actual long-term daily production (for production normalized limitations) or the Industrial User's actual long-term average daily flow rate (for concentration-based limitations). EPA prefers setting production normalized limitations, where feasible, since production normalized limitations can require flow reduction and reduces any potential for the substitution of dilution for treatment. Specifically, production normalized limitations are calculated from production normalized flows (volume of wastewater/ production unit) and incorporate wastewater flow reductions representing Best Available Technology Economically Achievable (BAT) (technology basis for Pretreatment Standards for Existing Sources, or PSES) or New Source Performance Standards (technology basis for Pretreatment Standards for New Sources, or PSNS).

EPA has established concentration-based Standards when production and achievable wastewater flow cannot be correlated nationally. EPA has explained how to calculate a mass limit in the Organic Chemicals, Plastics, and Synthetic Fibers (OCPSF) regulation. A mass limit is developed from the concentration-based Standard by multiplying the promulgated Pretreatment Standard (expressed as a concentration) by the Industrial User's actual long-term average daily flow rate. This approach re-enforces the requirements of the combined wastestream formula (

see

40 CFR 403.6(e)) to minimize the potential for dilution of process wastewaters by non-process wastewater. The combined wastestream formula of Section 403.6(e) applies to indirect dischargers where process wastewater is mixed prior to treatment with wastewater other than that generated by the regulated process.

What are the problems with mass limits based on flow?

Flow-based mass limits can, however, be difficult for the Control Authority to implement. To develop a flow-based mass limit, the Control Authority must determine the average daily flow rate of the Industrial User's regulated process wastewater and then multiply that value by the appropriate promulgated concentration Standard. This may be difficult in situations where the facility has highly variable production that leads to flows that often vary week-to-week or day-to-day. This is especially true for smaller facilities where: (1) The average daily flow rate of the Industrial User's regulated process wastewater may be infrequent or low and difficult to monitor; and (2) production tends to be more variable as the installation of equipment to provide flow equalization may not be practical.

In addition, testing for compliance with the flow-based mass limit requires having accurate information on the flow from all regulated processes at the time the sample is taken. Testing for compliance with a concentration limit only requires taking the wastewater sample and comparing the sampled concentration to the limit. In particular, since promulgation of the OCPSF Pretreatment Standards, there have been difficulties in getting Control Authorities and OCPSF facilities to correctly calculate flow-based mass limits, and to provide necessary data to determine compliance with the Standards. Deficiencies in Permits and control mechanisms have in the past hindered enforcement actions against these facilities. Enforcing mass-based Standards also becomes more complicated because there is an additional factor in the formula to calculate mass-based limits. In order to measure compliance, both flow and concentration of the pollutant need to be accurate and verified in order to produce legally enforceable mass-based results.

May alternative limits be developed for flow-based categorical Standards?

Currently, 40 CFR 403.6(c) allows Control Authorities to apply an equivalent concentration limit in addition to a current mass limit to implement a Pretreatment Standard. However, the regulations do not allow equivalent concentration limits in lieu of mass limits when the Pretreatment Standard requires a mass limit to be calculated from the promulgated concentration-based Standards and the average daily flow rate of the Industrial User's regulated process wastewater.

2. What changes did EPA propose?

EPA proposed to allow Control Authorities to use promulgated concentration-based limits instead of flow-based mass limits in establishing limits for Industrial Users in the OCPSF, Petroleum Refining, and Pesticide Chemicals categories. EPA proposed that the Control Authority would be allowed to apply such equivalent concentration limits only if the flow from the facility is so variable that the development of mass limits is impractical. EPA stipulated that 40 CFR 403.6(d) would continue to prohibit facilities from increasing flow in order to meet their concentration limits through dilution.

3. What changes is EPA finalizing in today's final rule?

The final rule allows Control Authorities to use concentration-based limits instead of flow-based mass limits for new and existing indirect dischargers in the OCPSF category, new indirect dischargers in the Petroleum Refining category, and new and existing indirect dischargers in the Pesticide Chemicals category. EPA is not limiting the Control Authority's authority to develop concentration limits to circumstances in which the Control Authority determines that the facility's flow is “so variable as to make mass limits impracticable.” EPA notes that Section 40 CFR 403.6(d) will continue to prohibit facilities from increasing flow in order to meet their concentration limits through dilution. As with other concentration limits, the Control Authority should be certain that dilution is not occurring and that the Discharge represents regulated process wastewater flows. The concentration may need to be adjusted using the combined wastestream formula in 40 CFR 403.6(e) if the wastestream is mixed with non-process wastewater or wastewater from other processes.

New 40 CFR 403.6(c)(6), applicable only to facilities in the OCPSF, Petroleum Refining, and Pesticide Chemicals categories, requires Control Authorities to document that dilution is not being substituted for treatment. To verify that equivalent concentration limits are not subsequently being met through use of dilution flows, Control Authorities should note that 40 CFR 403.12(e)(1) requires Categorical Industrial Users to provide information regarding maximum and average daily flows in their periodic reports, and enables them to require more detailed flow data as necessary. Using this authority, EPA recommends that Control Authorities consider specifying appropriate flow monitoring requirements and including evaluation of flow data in the review of periodic reports for Industrial Users subject to equivalent concentration Standards. This will enable Control Authorities to determine if there have been changes in flows that may indicate dilution, such as increases in process, non-process or overall flows, especially those not accompanied by production increases.

When are the equivalent concentration limits effective?

EPA notes that flow-based mass Standards, like all National categorical Pretreatment Standards, are self-

implementing for new and existing indirect dischargers in the OCPSF category and for new indirect dischargers in the Petroleum Refining category. Facilities to which these Standards are applicable must comply with the flow-based mass Standards unless a Permit or other control mechanism is issued by the Control Authority which establishes equivalent concentration limits under 40 CFR 403.6(c)(6). Where the Control Authority has not issued a control mechanism that establishes categorical concentration-based limits, the Industrial User must comply with the default flow-based mass limits as established in the applicable categorical Pretreatment Standard.

EPA notes that, for the Pesticides Chemicals category, in certain circumstances, an Industrial User may already be subject to concentration based limits rather than the otherwise required mass limits. Where the Control Authority has not established flow-based mass limits as required, Sections 40 CFR 455.26 and 455.27 provide that Industrial User must comply with the default concentration-based limits as established in the categorical Pretreatment Standard.

EPA emphasizes that for facilities in the OCPSF, Petroleum Refining, and Pesticide Chemicals categories, where the Control Authority has properly authorized the use of an equivalent concentration limit and has incorporated that limit into the Industrial User's control mechanism, the concentration limit replaces the mass limit. The final rule requires that an Industrial User must comply with the equivalent limit in lieu of the promulgated categorical Pretreatment Standard once the limit is incorporated into its control mechanism. The Control Authority may also determine that an Industrial User should be subject to both the flow-based mass limit as well as the concentration-based limit. When incorporated into the issued control mechanism, the Industrial User would have to comply with both limits. As with other equivalent concentration limits, as currently provided in 40 CFR 403.6(c), the equivalent limits being authorized under today's final rule are Pretreatment Standards for the purposes of Sec. 307(d) of the Clean Water Act and are federally enforceable.

4. Summary of Major Comments and EPA Response

A majority of the commenters supported the proposed rule as written, and most of the remaining commenters stated qualified support. Only one commenter opposed the proposal. The following section summarizes the most significant comments received and EPA's response.

Is Approval Authority review required of an Industrial User's proposed concentration limit prior to Control Authority approval?

A total of 22 commenters disagreed that it would be appropriate to require Approval Authority review of an Industrial User's proposed concentration limit prior to Control Authority approval. The primary reasoning stated was that such a requirement is not necessary and would create additional burden.

EPA notes that this provision is intended to allow the permit limit to be expressed in alternate units. It is not anticipated that this revision will change the Control Authority's enabling legislation to issue and enforce a control mechanism. As such, EPA does not consider this provision to be a modification of a POTW Pretreatment Program under 40 CFR 403.18, and, therefore, finds that a POTW's use of this provision is not subject to the specified approval procedures in this section. The new equivalent limit is subject to review as part of routine Approval Authority oversight activities, such as a Pretreatment Compliance Inspection or a Control Authority audit. In accordance with current regulations, Industrial User control mechanisms and information necessary for determining permit limitations and compliance must be publicly available.

Is this provision limited to highly variable flows?

Numerous commenters addressed the question of whether this provision should only be applied to highly variable flows as well as how to define the term “highly variable flow.” A total of 12 commenters stated that the rule should not be limited to only highly variable flows. Many mentioned the existence of factors in addition to highly variable flows that make implementation of flow-based mass limits impractical, such as the cost of obtaining accurate samples or the difficulty of sampling at facilities with very low flows. Ten commenters suggested that the Control Authority have the ability to define “highly variable flows” on a case-by-case basis since the basis for such a determination is highly site-specific and can vary from seasonal variations in flow to hourly variations in flow. Ten commenters thought that a 20 percent deviation from average flow is an adequate measure for “highly variable flow,” while five commenters requested that EPA not specify a definition for “highly variable flow” in the regulations.

EPA acknowledges that the there are numerous factors, many of which are site-specific, involved in determining that a facility has “highly variable flow(s)”, and agrees that it would be difficult to establish a clear-cut definition of “highly variable flow” that would apply to all facilities. To be consistent with the goals of providing flexibility in this rule, and to support the Control Authority's discretion on this site specific issue, EPA has decided to allow Control Authorities to determine when the acceptable circumstances exist to allow the use of concentration limits.

Is this provision consistent with the Clean Water Act?

The commenter that opposed this provision stated that EPA lacks the authority to create a variance or an alternative implementation mechanism and therefore will violate sections 307 and 402 of the Clean Water Act. The commenter also questioned the need for this proposed change, suggested that it will interfere with ongoing enforcement of the categorical Standards and the statutory deadlines for achieving them, and suggested that the record does not demonstrate that this proposed change will protect POTWs and the environment.

EPA is promulgating the changes to its Pretreatment Regulations in part under section 307(b) of the Clean Water Act. Section 307(b) clearly authorizes EPA from time to time to revise Pretreatment Standards as “control technology, processes, operating methods or other alternatives change.” Therefore, today's action is not in violation of section 307(b) to the extent this provision amends the Pretreatment Standards for the OCPSF, the Petroleum Refining, and the Pesticide Chemicals Categories. As EPA has explained, the amendments to the regulations will facilitate both User's compliance and POTW oversight. EPA notes that complia

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