Effluent Limitations Guidelines, Pretreatment Standards, and New Source Performance Standards for the Landfills Point Source Category

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 136 and 445

[FRL-6503-5]

RIN 2040-AC23

Effluent Limitations Guidelines, Pretreatment Standards, and New Source Performance Standards for the Landfills Point Source Category

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Final rule.

SUMMARY:

This final rule represents the culmination of the Agency's effort to develop Clean Water Act (CWA) national effluent limitations guidelines and pretreatment standards for wastewater discharges from certain landfills. The final regulation establishes technology-based effluent limitations for wastewater discharges associated with the operation and maintenance of new and existing hazardous and non-hazardous landfill facilities regulated, respectively, under Subtitle C and Subtitle D of the Resource Conservation and Recovery Act (RCRA). Sources of landfill wastewater include, but are not limited to, landfill leachate and gas collection condensate. Today's final rule does not establish pretreatment standards for the introduction of pollutants into Publicly Owned Treatment Works (POTW) from the operation of new and existing landfills regulated under Subtitle C or Subtitle D of RCRA.

The rule does not apply to wastewater discharges from “captive” landfills—those landfills associated with other industrial or commercial activities, in most circumstances. For example, it does not apply to captive landfills that only receive wastes generated by the industrial operation directly associated with the landfill. In addition, the rule does not apply to captive landfills that receive both wastes generated by the industrial operation directly associated with the landfill as well as other wastes, so long as the other wastes are similar in nature to the wastes generated by the industrial operation directly associated with the landfill. Further, the regulation does not apply to wastewater discharges associated with treatment of contaminated ground water from hazardous and non-hazardous landfills.

The final effluent limitations guidelines will benefit the environment by removing 900,000 pounds of pollutants per year at an estimated annualized cost of $7.6 million.

DATES:

This regulation shall become effective February 18, 2000.

ADDRESSES:

For additional technical information write to Mr. Michael C. Ebner, Engineering and Analysis Division (4303), U.S. EPA, 401 M Street S.W., Washington, D.C. 20460 or send E-mail to:

ebner.michael@epa.gov

or call at (202)260-5397. For additional economic information contact Mr. William Anderson at the address above or send E-mail to:

anderson.william@epa.gov

or call (202) 260-5131.

The complete record (excluding confidential business information) for this Clean Water Act rulemaking is available for review at EPA's Water Docket, Room EB57; 401 M Street, SW, Washington, DC 20460. For access to Docket materials, call (202) 260-3027 between 9 a.m. and 3:30 p.m. for an appointment. The record for this rulemaking has been established under docket number W-97-17, and includes supporting documentation, but does not include any information claimed as Confidential Business Information (CBI). The EPA public information regulation (40 CFR Part 2) provides that a reasonable fee may be charged for copying.

FOR FURTHER INFORMATION CONTACT:

For additional technical information call Mr. Michael Ebner at (202) 260-5397. For additional information on the economic impact analyses contact Mr. William Anderson at (202) 260-5131.

SUPPLEMENTARY INFORMATION:

Judicial Review

In accordance with 40 CFR 23.2, this rule will be considered promulgated for purposes of judicial review at 1:00 p.m. Eastern time on February 2, 2000. Under section 509(b)(1) of the Act, judicial review of this regulation can be obtained only by filing a petition for review in the United States Court of Appeals within 120 days after the regulation is considered final for purposes of judicial review. Under section 509(b)(2) of the Act, the requirements in this regulation may not be challenged later in civil or criminal proceedings brought by EPA to enforce these requirements.

Regulated Entities:

Entities potentially regulated by this action include:

Category

Examples of regulated entities

Industry

Landfills regulated under Subtitle C or Subtitle D of RCRA that collect and discharge landfill generated wastewater to surface waters of the U.S., unless the landfills are directly associated with other industrial or commercial facilities.

State, municipal or tribal Government

Landfills regulated under Subtitle C or Subtitle D of RCRA that collect and discharge landfill generated wastewater to surface waters of the U.S., unless the landfills are directly associated with other industrial or commercial facilities.

Federal Government

Landfills regulated under Subtitle C or Subtitle D of RCRA that collect and discharge landfill generated wastewater to surface waters of the U.S., unless the landfills are directly associated with other industrial or commercial facilities.

The preceding 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 facility is regulated by this action, you should carefully examine the applicability criteria in § 445.1 of the final rule. If you have questions regarding the applicability of this action to a particular entity, consult one of the persons listed in the preceding

FOR FURTHER INFORMATION CONTACT

section.

Compliance Dates

The compliance date for NSPS is the date the new source commences discharging. Compliance deadline for BPT, BCT, and BAT for a facility is immediately upon issuance or reissuance of the National Pollutant Discharge Elimination System (NPDES) permit.

Supporting Documentation

Several major documents further describe the technical and economic basis for the regulations promulgated today. These include:

1. “Development Document for Final Effluent Limitations Guidelines and Standards for the Landfills Point Source

Category” (EPA 821-R-99-019). Hereafter referred to as the Technical Development Document, it presents EPA's technical conclusions concerning the rule. EPA describes, among other things, the data collection activities in support of the rule, the wastewater treatment technology options, wastewater characterization, and the estimation of costs to the industry.

2. “Economic Analysis for Final Effluent Limitations Guidelines and Standards for the Landfills Point Source Category” (EPA 821-B-99-005).

3. “Statistical Support Document for Final Effluent Limitations Guidelines and Standards for the Landfills Point Source Category” (EPA 821-B-99-007).

4. “Environmental Assessment for Final Effluent Limitations Guidelines and Standards for the Landfills Point Source Category” (EPA 821-B-99-006).

EPA made drafts of these documents available for comment at proposal and revised the materials where warranted in response to the comments. EPA did not submit the documents for peer review because the Agency concluded that additional review was not required because the scientific and technical methodologies being used are not significantly different from those used in the development of past effluent guidelines.

How to Obtain Supporting Documents:

The Technical and Economic Development Documents can be obtained through EPA's website on the Internet, located at www.epa.gov/OST/guide/2lndfls. All of the supporting documents are also available from the Office of Water Resource Center, RC-4100, U.S. EPA, 401 M Street SW, Washington, D.C., 20460; telephone (202) 260-7786 for the voice mail publication request.

Table of Contents

I. Legal Authority

II. Background

A. Clean Water Act

B. Section 304(m) Requirements

C. Brief History of Landfill Industry and Proposed Guidelines

III. The Final Landfills Effluent Limitations Guidelines and Standards

A. Overview of Final Rule

B. Applicability and Scope of the Final Rule

C. Subcategorization

D. Profile of the Landfills Industry

E. Technology Basis for Final Rule

F. Development of Effluent Limitations

G. Treatment Systems Selected for Basis of Regulation

IV. Assessment of Costs and Impacts

A. Methodology for Estimating Costs and Pollutant Reductions Achieved by Treatment Technologies

B. Costs of Compliance

C. Pollutant Reductions

V. Economic Analysis

A. Introduction and Overview

B. Summary of Economic Impacts

VI. Water Quality Analysis and Environmental Benefits

A. Introduction

B. Methodology Used for Estimating Water Quality Impacts and Benefits

C. Estimated National Water Quality Impacts and Results

VII. Non-water Quality Environmental Impacts

A. Air Pollution

B. Solid Waste Generation

C. Energy Requirements

VIII. Regulatory Implementation

A. Implementation of Limitations and Standards

B. Upset and Bypass Provisions

C. Variances and Modifications

D. Relationship of Effluent Limitations to NPDES Permits and Monitoring Requirements

E. Implementation for Facilities With Landfills in Multiple Subcategories

F. Implementation for Contaminated Ground Water Flows and Wastewater from Recovering Pumping Wells

G. Implementation for Subtitle D Landfills Which Received Newly Listed Hazardous Wastes in the Past

H. Implementation for Superfund Response Actions at Landfills

I. Implementation for TSCA landfills

J. Implementation for Landfills Located at Centralized Waste Treatment Facilities

K. Determination of Similar Wastes for Captive Landfill Facilities

L. Analytical Methods

IX. Regulatory Requirements

A. Executive Order 12866

B. Regulatory Flexibility Act and the Small Business Regulatory Enforcement Fairness Act of 1996 (SBREFA)

C. Submission to Congress and the General Accounting Office

D. Paperwork Reduction Act

E. Unfunded Mandates Reform Act

F. Executive Order 13084: Consultation and Coordination with Indian Tribal Governments

G. Executive Order 13132 (Federalism)

H. National Technology Transfer and Advancement Act

I. Executive Order 13045 and Protecting Children's Health

X. Summary of Proposal Comments and Responses

Appendix A: Definitions, Acronyms, and Abbreviations

I. Legal Authority

The U.S. Environmental Protection Agency is promulgating these regulations under the authority of Sections 301, 304, 306, 307, 308, 402, and 501 of the Clean Water Act, 33 U.S.C.1311, 1314, 1316, 1317, 1318, 1342, and 1361.

II. Background

A. Clean Water Act

Congress adopted the Clean Water Act (CWA) to “restore and maintain the chemical, physical, and biological integrity of the Nation's waters” (Section 101(a), 33 U.S.C. 1251(a)). To achieve this goal, the CWA prohibits the discharge of pollutants into navigable waters except in compliance with the statute. The Clean Water Act confronts the problem of water pollution on a number of different fronts. Its primary reliance, however, is on establishing restrictions on the types and amounts of pollutants discharged from various industrial, commercial, and public sources of wastewater.

Congress recognized that regulating only those sources that discharge effluent directly into the nation's waters would not be sufficient to achieve the CWA's goals. Consequently, the CWA requires EPA to promulgate nationally applicable pretreatment standards which restrict pollutant discharges for those who discharge wastewater indirectly through sewers flowing to publicly-owned treatment works (POTWs) (Section 307(b) and (c), 33 U.S.C. 1317(b) and (c)). National pretreatment standards are established for those pollutants in wastewater from indirect dischargers which may pass through or interfere with POTW operations. Generally, pretreatment standards are designed to ensure that wastewater from direct and indirect industrial dischargers are subject to similar levels of treatment. In addition, POTWs are required to implement local pretreatment limits applicable to their industrial indirect dischargers to satisfy any local requirements (40 CFR 403.5).

Direct dischargers must comply with effluent limitations in National Pollutant Discharge Elimination System (“NPDES”) permits; indirect dischargers must comply with pretreatment standards. These limitations and standards are established by regulation for categories of industrial dischargers and are based on the degree of control that can be achieved using various levels of pollution control technology.

1. Best Practicable Control Technology Currently Available (BPT)—Sec. 304(b)(1) of the CWA

In the regulations for an industry category, EPA defines BPT effluent limits for conventional, priority,

1

and

nonconventional pollutants. In specifying BPT, EPA looks at a number of factors. EPA first considers the cost of achieving effluent reductions in relation to the effluent reduction benefits. The Agency also considers the age of the equipment and facilities, the processes employed and any required process changes, engineering aspects of the control technologies, non-water quality environmental impacts (including energy requirements), and such other factors as the Agency deems appropriate (CWA 304(b)(1)(B)). Traditionally, EPA establishes BPT effluent limitations based on the average of the best performances of facilities within the industry of various ages, sizes, processes or other common characteristic. Where existing performance is uniformly inadequate, EPA may require higher levels of control than currently in place in an industrial category if the Agency determines that the technology can be practically applied.

1

In the initial stages of EPA CWA regulation, EPA efforts emphasized the achievement of BPT limitations for control of the “classical” pollutants (

e.g.,

TSS, pH, BOD

5

). However, nothing on the face of the statute explicitly restricted BPT limitations to such pollutants. Following passage of the Clean Water Act of 1977 with its requirement for point sources to achieve best available technology limitations to control discharges of toxic pollutants, EPA shifted its focus to address the listed priority pollutants under the guidelines program. BPT

guidelines continue to include limitations to address all pollutants.

2. Best Conventional Pollutant Control Technology (BCT)—Sec. 304(b)(4) of the CWA

The 1977 amendments to the CWA required EPA to identify effluent reduction levels for conventional pollutants associated with BCT for discharges from existing industrial point sources. In addition to other factors specified in Section 304(b)(4)(B), the CWA requires that EPA establish BCT limitations after consideration of a two part “cost-reasonableness” test. EPA explained its methodology for the development of BCT limitations in July 1986 (51 FR 24974).

Section 304(a)(4) designates the following as conventional pollutants: biochemical oxygen demand (BOD

5

), total suspended solids (TSS), fecal coliform, pH, and any additional pollutants defined by the Administrator as conventional. The Administrator designated oil and grease as an additional conventional pollutant on July 30, 1979 (44 FR 44501).

3. Best Available Technology Economically Achievable (BAT)—Sec. 304(b)(2) of the CWA

In general, BAT effluent limitations guidelines represent the best economically achievable performance of plants in the industrial subcategory or category. The factors considered in assessing BAT include the cost of achieving BAT effluent reductions, the age of equipment and facilities involved, the process employed, potential process changes, and non-water quality environmental impacts, including energy requirements. The Agency retains considerable discretion in assigning the weight to be accorded these factors. BAT limitations may be based on effluent reductions attainable through changes in a facility's processes and operations. As with BPT, where existing performance is uniformly inadequate, BAT may require a higher level of performance than is currently being achieved based on technology transferred from a different subcategory or category. BAT may be based upon process changes or internal controls, even when these technologies are not common industry practice.

4. New Source Performance Standards (NSPS)—Sec. 306 of the CWA

NSPS reflect effluent reductions that are achievable based on the best available demonstrated control technology. New facilities have the opportunity to install the best and most efficient production processes and wastewater treatment technologies. As a result, NSPS should represent the most stringent controls attainable through the application of the best available control technology for all pollutants (

i.e.,

conventional, nonconventional, and priority pollutants). In establishing NSPS, EPA is directed to take into consideration the cost of achieving the effluent reduction and any non-water quality environmental impacts and energy requirements.

5. Pretreatment Standards for Existing Sources (PSES)—Sec. 307(b) of the CWA

PSES are designed to prevent the discharge of pollutants that pass through, interfere-with, or are otherwise incompatible with the operation of publicly-owned treatment works (POTW). The CWA authorizes EPA to establish pretreatment standards for pollutants that pass through POTWs or interfere with treatment processes or sludge disposal methods at POTWs. Pretreatment standards for existing sources are technology-based and analogous to BAT effluent limitations guidelines.

The General Pretreatment Regulations, which set forth the framework for the implementation of categorical pretreatment standards, are found at 40 CFR Part 403. Those regulations contain a definition of pass-through that addresses localized rather than national instances of pass-through and establish pretreatment standards that apply to all non-domestic discharges. See 52 FR 1586, January 14, 1987.

6. Pretreatment Standards for New Sources (PSNS)—Sec. 307(b) of the CWA

Like PSES, PSNS are designed to prevent the discharges of pollutants that pass through, interfere-with, or are otherwise incompatible with the operation of POTWs. PSNS are to be issued at the same time as NSPS. New indirect dischargers have the opportunity to incorporate into their plants the best available demonstrated technologies. The Agency considers the same factors in promulgating PSNS as it considers in promulgating NSPS.

B. Section 304(m) Requirements

Section 304(m) of the CWA, added by the Water Quality Act of 1987, requires EPA to establish schedules for (1) reviewing and revising existing effluent limitations guidelines and standards (“effluent guidelines”) and (2) promulgating new effluent guidelines. On January 2, 1990, EPA published an Effluent Guidelines Plan (55 FR 80) that established schedules for developing new and revised effluent guidelines for several industry categories. One of the industries for which the Agency established a schedule was the Hazardous Waste Treatment Industry.

The Natural Resources Defense Council (NRDC) and Public Citizen, Inc. filed suit against the Agency, alleging violation of Section 304(m) and other statutory authorities requiring promulgation of effluent guidelines (

NRDC et al.

v.

Reilly,

Civ. No. 89-2980 (D.D.C.)). Under the terms of the consent decree in that case, as amended, EPA agreed, among other things, to propose effluent guidelines for the “Landfills and Industrial Waste Combusters” category by November 1997 and final action by November 1999. Although the Consent Decree lists “Landfills and Industrial Waste Combusters” as a single entry, EPA is publishing separate regulations for Industrial Waste Combusters and for Landfills.

C. Brief History of Landfills Industry and Proposed Guidelines

The growth of the landfills industry is a direct result of the Resource Conservation and Recovery Act (RCRA) and subsequent EPA and State regulations that establish the conditions under which solid waste may be disposed. The implementation of the increased control measures required by RCRA has had a number of ancillary effects on the landfill industry. On the one hand, it has forced many landfills to close because they lacked adequate on-site controls to protect against migration of hazardous constituents

from the landfill, and it was not economical to upgrade the landfill facility. As a result, a large number of landfills, especially facilities serving small populations, have closed rather than incur the significant expense of upgrading.

Conversely, large landfill operations have taken advantage of economies of scale by serving wide geographic areas and accepting an increasing portion of the nation's solid waste. For example, responses to EPA's Waste Treatment Industry Survey indicated that 75 percent of the nation's municipal solid waste is deposited in large landfills representing only 25 percent of the landfill population.

EPA has identified several trends in the waste disposal industry that may increase the quantity of leachate produced by landfills. More stringent RCRA regulation and the restrictions on the management of wastes have increased the amount of waste disposed at landfills as well as the number of facilities choosing to send wastes off-site to commercial facilities in lieu of pursuing on-site management options. This will increase treated leachate discharges from the nation's landfills, thus potentially putting at risk the integrity of the nation's waters. Further, as a result of the increased number of leachate collection systems, the volume of leachate requiring treatment and disposal has greatly increased.

On February 6, 1998, EPA proposed Clean Water Act (CWA) national effluent limitations guidelines and pretreatment standards for wastewater discharges from landfill facilities regulated under Subtitle C or Subtitle D of the Resource Conservation and Recovery Act (RCRA). 63 FR 6425.

The proposed regulation divided the landfills industry into two subcategories: (1) RCRA Subtitle C Hazardous Waste Landfill Subcategory, and (2) RCRA Subtitle D Non-Hazardous Waste Landfill Subcategory. For the RCRA Subtitle C subcategory, EPA proposed BPT, BAT, BCT, and NSPS concentration-based limitations for 15 pollutants: BOD

5

, TSS, ammonia, arsenic (total), chromium (total), zinc (total), alpha-terpineol, aniline, benzene, benzoic acid, naphthalene, p-cresol, phenol, pyridine, and toluene; EPA also proposed limitations for pH. For PSES and PSNS for the hazardous waste landfill subcategory, EPA proposed pretreatment standards for six pollutants: ammonia, alpha-terpineol, aniline, benzoic acid, p-cresol, and toluene.

For the RCRA Subtitle D subcategory, EPA proposed BPT, BAT, BCT, and NSPS concentration-based limitations for nine parameters. These were BOD

5

, TSS, ammonia, zinc (total), alpha-terpineol, benzoic acid, p-cresol, phenol, toluene; EPA also proposed limitations for pH. EPA did not propose PSES or PSNS for the RCRA Subtitle D subcategory.

As proposed, the guidelines would not apply to wastewater discharges from captive landfills located at industrial facilities under certain conditions. The guidelines did not apply if the industrial facility commingled landfill process wastewater with non-landfill process wastewater for treatment, provided that the landfill received only waste generated on-site or waste generated from a similar activity at another facility under the same corporate structure. Further, the proposed regulation did not apply to wastewater discharges associated with treatment of contaminated ground water from hazardous and non-hazardous landfills.

EPA solicited public comment on the proposed rule; the comment period was open from February 6 to May 7, 1998. Section [X] describes the major comments on the proposed rule and EPA's responses. The public record includes a comment summary and response document for this rulemaking.

III. The Final Landfills Effluent Limitations Guidelines and Standards

This section discusses the applicability of the final rule, the landfill wastewater flows subject to the rule, regulatory options considered, and the rationale for the selected technology options.

A. Overview of Final Rule

Today EPA is promulgating technology-based effluent limitations for wastewater discharges to navigable waters associated with the operation of new and existing hazardous and non-hazardous landfill facilities regulated under Subtitle C or Subtitle D of the Resource Conservation and Recovery Act (RCRA). EPA decided to promulgate effluent limitation guidelines using the same subcategorization approach outlined in the proposal. For the RCRA Subtitle C subcategory, EPA is promulgating BPT, BAT, BCT, and NSPS (BPT/BCT/BAT/NSPS) limitations for fourteen parameters. These are BOD

5

, TSS, ammonia, arsenic (total), chromium (total), zinc (total), alpha-terpineol, aniline, benzoic acid, naphthalene, p-cresol, phenol, pyridine, and pH. For the RCRA Subtitle D subcategory, EPA is promulgating BPT/BCT/BAT/NSPS limitations for nine parameters. These are BOD

5

, TSS, ammonia, zinc (total), alpha-terpineol, benzoic acid, p-cresol, phenol, and pH. Chapter 7 of the Technical Development Document describes in detail EPA's selection of pollutants to regulate. The final rule does not establish PSES or PSNS for either subcategory.

B. Applicability and Scope of the Final Rule

Today's final effluent limitations guidelines and standards cover pollutants in wastewater discharges associated only with the operation and maintenance of those landfills regulated under Subtitles C and D of the Resource Conservation and Recovery Act (RCRA).

2

The rule applies to wastewater generated at active landfills subject to Subtitle C of RCRA and Subtitle C landfills that closed after November 19, 1980, the effective date of 40 CFR Part 265. The guidelines do not apply to discharges of landfill wastewater associated with hazardous landfills that went into a permanently inactive status (

i.e.,

they were not receiving any more waste) before the effective date of 40 CFR Part 265. Similarly, the rule applies to wastewater generated at active landfills subject to Subtitle D of RCRA and Subtitle D landfills that closed after October 15, 1979, the effective date of 40 CFR Part 257. The guidelines do not apply to discharges of landfill wastewater associated with non-hazardous landfills that went into a permanently inactive status (

i.e.,

they were not receiving any more waste) before the effective date of 40 CFR Part 257.

2

EPA's Subtitle C and Subtitle D regulations define “landfill”.

See

40 CFR 257.2, 258.2 (“municipal solid waste landfill”) and 260.10. Permitted Subtitle C landfills are authorized to accept hazardous wastes as defined in 40 CFR Part 261. Subtitle D landfills are authorized to receive municipal, commercial or industrial waste that is not hazardous (as well as hazardous waste excluded from regulation under Subtitle C).

Furthermore, this rule does not apply to wastewater discharges associated with the operation and maintenance of land application or treatment units, surface impoundments, underground injection wells, waste piles, salt dome or bed formations, underground mines, caves or corrective action units.

3

Additionally, this guideline does not apply to waste transfer stations, or any wastewater not directly attributed to the operation and maintenance of Subtitle C or Subtitle D landfill units. Consequently, wastewater such as that generated in off-site washing of vehicles used in landfill operations is not within the scope of this guideline.

3

These terms are defined at 40 CFR 257.2 and 260.10.

1. Captive Landfills

In developing the proposed guidelines, an important question EPA addressed was how to treat landfill leachate generated at a landfill that is associated with an industrial or commercial operation—so-called “captive” landfills. Currently, in the case of wastewater sources that are not subject to effluent limitations guidelines and standards, NPDES permit writers must impose limitations on discharges of these wastewater sources that are developed on a case-by-case, best professional judgment (BPJ) basis. Similarly, an indirect discharger may not introduce any pollutants to a POTW from these sources that will pass through or interfere with the POTW's operations. Generally, each POTW is required to develop a pretreatment program and enforce the prohibition on pass through and interference through specific local limits.

EPA initially considered development of effluent guidelines to address any landfill discharging directly to surface waters of the United States or introducing pollutants into a POTW. Consequently, EPA's technical evaluation for the proposal included an assessment of virtually all landfill facilities which collect wastewater as a result of landfilling operations. EPA proposed to exclude wastewater discharges from captive landfills located at industrial facilities in specific circumstances. In the proposal, a captive landfill would not have been subject to the guidelines (1) if it commingled landfill process wastewater with non-landfill process wastewater for treatment, and (2) the landfill received only waste generated on-site or waste generated from a similar activity at another facility under the same corporate structure.

EPA now determined that these requirements are too restrictive and therefore the Agency has decided not to include captive landfills within the scope of this guideline except in a limited number of circumstances. The Agency wants to stress, however, that the effect of today's decisions is not to allow these wastewater sources to escape treatment. Landfill wastewater at captive facilities is and will remain subject to treatment and controls on its discharge. The CWA requires wastewater discharges to meet technology-based effluent limitations on the discharge whether the mechanism for imposing these limitations is EPA-established national effluent limitations guidelines or a permit writer's imposition on a case-by-case basis of BPJ limitations. In like manner, in order to prevent pass through or interference, indirect dischargers must limit their introduction of pollutants to a POTW whether EPA has established national categorical pretreatment standards for the discharge or a POTW has established local limits.

The following describes the applicability of the final rule to captive landfills. The final rule does not apply to discharges of landfill wastewater from captive landfills so long as one or more of the following conditions are met:

—The captive landfill is operated in conjunction with other industrial or commercial operations, and it only receives wastes generated by the industrial or commercial operation directly associated with the landfill.

—The landfill is operated in conjunction with other industrial or commercial operations and it receives both wastes generated by the industrial or commercial operation directly associated with the landfill as well as other wastes and the other wastes received for landfill disposal are generated by a facility that is subject to the same provisions in 40 CFR Subchapter N as the receiving facility directly associated with the landfill.

—The landfill is operated in conjunction with other industrial or commercial operations and it receives wastes generated by the industrial or commercial operation directly associated with the landfill as well as other wastes and the other wastes are similar in nature to the wastes generated by the industrial or commercial operation directly associated with the landfill.

—The landfill is operated in conjunction with a Centralized Waste Treatment (CWT) facility subject to 40 CFR Part 437 so long as the CWT facility commingles the landfill wastewater with other non-landfill wastewater for treatment. If a CWT facility discharges landfill wastewater separately from other CWT wastewater or commingles the wastewater from its landfill only with wastewater from other landfills, then the landfill discharge is subject to this part.

—The landfill is operated in conjunction with other industrial or commercial operations, and it receives wastes from public service activities (as defined in Appendix A) and the landfill does not receive a fee or other remuneration for the disposal service.

For the final rule, EPA has modified the proposal to remove the requirement that a facility must commingle its wastewater from a captive landfill with the facility's non-landfill process wastewater for treatment in order not to be subject to the landfills effluent guideline, in most circumstances. For the reasons described in detail below, EPA did not remove the commingling requirement for CWTs. In addition, EPA also changed the conditions under which captive landfills may accept off-site wastes and not be subject to this guideline.

In the proposal, EPA stated that the commingling requirement ensures that wastewater from captive landfills will undergo adequate treatment (treatment that is comparable to the level of treatment that would be required by the landfills effluent guideline) prior to discharge. EPA determined that the commingling of landfill wastewater with industrial wastewater for treatment was an unnecessary requirement to impose in nationally applicable regulations for the reasons discussed below. Permit writers are establishing appropriate limits on these discharges by either applying the effluent limitations guidelines applicable to the associated industrial activity to the discharge or developing other BPJ limitations. EPA recommends that permit writers use this guideline when developing these BPJ limitations.

From the information developed by the Agency for this rulemaking and confirmed by comments on the proposal, EPA has concluded that landfill wastewater generated by captive landfills operated in conjunction with and receiving the bulk of their waste from an industrial or commercial operation will have a similar pollutant profile to the wastewater generated in the industrial or commercial operation. EPA has further concluded that the wastewater generated by landfill operations at most of the captive facilities are already subject to effluent guidelines. In the circumstances in which the wastewater is not expressly subject to effluent guidelines, EPA has determined that permit writers generally impose BPJ limitations on the discharge of landfill wastewater that are similar to the limitations applicable to the discharge of industrial process wastewater whether commingled or not. EPA has compared the wastewater treatment technologies employed at many of the industrial facilities operating landfills in conjunction with the industrial or commercial operations to the treatment technologies that EPA used as the basis for the BPT/BAT limits in this effluent guideline. The Agency's review of such situations shows that the landfill wastewater receives treatment that is comparable or better than the level of treatment that would be required by the landfills effluent guideline.

Consequently, EPA has decided to eliminate the requirement of commingling as a condition for a captive landfill not to be subject to landfill limitations and standards (except in the case of CWTs). EPA has concluded that landfill wastewater at captive landfills is now and will continue to receive adequate treatment because the landfill wastewater generally must meet the same effluent limitations that would have been required had the waste streams been commingled. In cases where the permit writer is establishing BPJ limitations for the discharge of captive landfill wastewater that is not commingled for treatment, the permit writer should look at the effluent guidelines applicable to the associated industrial operation and the effluent guidelines being promulgated today for potential guidance in setting those limitations.

Because of the nature of most CWTs, EPA determined that the reasons that generally supported exclusion of other captive landfills would not apply in the case of CWTs. As explained above, EPA concluded that a captive landfill which only received wastes generated in an industrial or commercial operation directly associated with the landfill or similar wastes would generate a leachate with a similar pollutant profile to the other wastewater streams produced at the industrial operation. In such circumstances, the data reviewed by EPA showed that the landfill wastewater and other industrial wastewater are generally commingled for treatment and subject to the same discharge limitations. In these circumstances, it was appropriate not to subject the landfill wastestream to this guideline.

Because a CWT, by its very nature, may generate a wide array of different solid wastes for landfill disposal, it may generate a leachate that varies significantly from other streams being treated at the CWT at the time the leachate is collected. Therefore, EPA concluded that the basis for the exclusion—the similarity in wastewater—would not necessarily apply in the case of CWTs. EPA decided that, in order to ensure that the CWT landfill wastewater is treated adequately, that the landfill wastewater from a CWT landfill should be commingled with other CWT wastewater for treatment.

Based on comments received, the Agency also determined that the requirement in the proposal that solid wastes deposited in the captive landfill must either be generated on-site or from an off-site facility under the same corporate structure was too restrictive and could often prohibit a company from safely and properly disposing of solid wastes accepted from tolling, remediation, product stewardship, and public service activities.

In the proposal, EPA narrowly limited the universe of captive landfills that fall outside the scope of this rule to captive landfills that only accepted wastes from on-site or from off-site facilities under the same corporate structure. The reason for this was essentially to ensure that the captive landfills were only accepting wastes that would be similar to those wastes generated on-site. This in turn would provide some degree of assurance that the leachate generated from these wastes would be compatible with the on-site industrial wastewater treatment. However, from the comments submitted on this issue, EPA determined this waste acceptance criterion for the captive exclusion was too restrictive. Those commenting on this issue identified several waste acceptance practices that are commonly used by captive landfills that would not meet the proposed exclusion criteria but are consistent with EPA's objective that landfill leachate receive treatment compatible with its expected constituents. Many of these current waste disposal practices are activities that EPA encourages, and therefore EPA has revised the exclusion criteria pertaining to waste acceptance for captive/intracompany landfills in order to accommodate these disposal practices.

Specifically, several commenters requested that EPA broaden the criteria for determining those captive landfills that fall outside the scope of this rule to include waste acceptance from tolling and contract manufacturers, product stewardship, company partnerships, and remediation activities. EPA concluded that waste disposal at captive landfills from these types of activities will, in most cases, result in leachate that will be adequately controlled through the implementation of categorical or BPJ limitations at the facility. However, EPA remains concerned that there are circumstances in which inter-company waste products deposited in the landfill may result in contaminants in the leachate that may not be compatible with the existing industrial wastewater treatment system or may not be covered adequately by the existing industrial effluent guideline. Therefore, one of the alternative conditions for the revised applicability provisions of the guideline described above for captive landfills provides that waste accepted at the captive landfill must be of a similar nature to the wastes generated at the operation with the associated landfill. Thus, the permitting authority must determine that wastes accepted for disposal at a captive landfill are of a similar nature to the waste generated at the facility directly associated with the captive landfill. Factors that the permit writer should consider in determining whether a waste is similar are described at Section [VIII].

In addition, commenters also requested that EPA include the acceptance of wastes for disposal as a public service as a category of landfill practices that qualify for the captive exclusion. EPA agrees and has included such a provision. EPA applauds the efforts of manufacturing facilities who provide members of their communities with a cost effective and environmentally safe means for disposing of their solid waste. Therefore, in the final rule, EPA determined that this rule shall not apply to those landfills operated in conjunction with other industrial or commercial operations which receive other wastes from public service activities so long as the company owning the landfill does not receive a fee or other remuneration for the disposal service. EPA's decision not to subject captive landfills that accept off-site wastes for disposal as a public service is not inconsistent with its decision generally to condition non-applicability on the similarity of wastes accepted for disposal. Based on its review of data collected for this guideline and comments received, EPA concluded that the quantity of wastes accepted for disposal as a public service would not in any measurable way affect the pollutant profile of the leachate generated by the landfill even if dissimilar. Of course, these wastewater flows still remain subject to treatment to achieve BPJ permit limits reflecting the landfill contribution to the facility discharge.

The Agency has determined that whether captive landfills accepting wastes from off-site or from a company not within the same corporate structure on a non-commercial basis should be subject to the landfills effluent guideline should hinge on the ability of the captive landfill to handle the waste in an appropriate manner. Therefore, the Agency concluded that waste acceptance criterion for determining those captive landfills that fall outside the scope of this rule should be based on the similarity of the waste accepted for disposal from another facility to the waste generated by the industrial or commercial operation directly associated with the landfill. In the case of captive landfills treating similar

wastes, the permit writer should base permit limits on limitations for the guideline to which the industrial or commercial operation is subject or establish BPJ limitations. Again, the permit writer, if developing BPJ limitations, should consider today's guidelines as guidance in this effort.

2. Landfill Wastewater—The wastewater covered by the rule includes leachate, gas collection condensate, drained free liquids, laboratory-derived wastewater, contaminated storm water and contact washwater from truck exteriors and surface areas which have come in direct contact with solid waste at the landfill facility. However, ground water and wastewater from recovery pumping well operations which have been contaminated by a landfill and are collected and discharged are excluded from this guideline and covered by BPJ limitations. This section later discusses the exclusion from the rule for contaminated ground water flows and Section [VIII] of today's final rule addresses implementation issues associated with contaminated ground water. The wastewater associated with the landfills industry is described below.

a. Leachate, as defined in 40 CFR 258.2, is liquid that has passed through or emerged from solid waste and contains soluble, suspended, or miscible materials removed from such waste. Over time the potential for certain pollutants to move into the wider environment increases. As water passes through the landfill, it may “leach” pollutants from the disposed waste moving them deeper into the soil. This presents a potential hazard to public health and the environment through ground water contamination and other means. One measure used to prevent the movement of toxic and hazardous waste constituents from a landfill is a landfill liner operated in conjunction with a leachate collection system. Leachate is typically collected from a liner system placed at the bottom of the landfill. Leachate also may be collected through the use of slurry walls, trenches or other containment systems. The leachate generated varies from site to site based on a number of factors including: the types of waste accepted; operating practices (including shedding, daily cover and capping); the depth of fill; compaction of wastes; annual precipitation; and landfill age. Landfill leachate accounts for over 95 percent of the wastewater covered by this rule.

b. Gas Collection Condensate is liquid which has condensed in a gas collection system during the extraction of gas from the landfill. Gases such as methane and carbon dioxide are generated due to microbial activity within the landfill and must be removed to avoid hazardous, explosive conditions. In gas collection systems, gases containing high concentrations of water vapor condense in traps staged throughout the gas collection network. The gas condensate may contain volatile, semi-volatile, and metal compounds and usually accounts for a relatively small percentage of flow from a landfill.

c. Drained Free Liquids are aqueous wastes drained from waste containers (e.g. drums, trucks) or wastewater resulting from waste stabilization prior to landfilling. Landfills which accept containerized waste may generate this type of wastewater. Wastewater generated from these waste processing activities is collected and usually combined with other landfill generated wastewater for treatment at the wastewater treatment plant.

d. Truck/Equipment Washwater is generated during either truck or equipment washes at landfills. During routine maintenance or repair operations, trucks and/or equipment used within the landfill (e.g., loaders, compactors, or dump trucks) are washed and the resultant wastewater is collected for treatment. In addition, it is common practice for many facilities to wash the wheels, body, and undercarriage of trucks used to deliver the waste to the open landfill face upon leaving the landfill. On-site wastewater treatment equipment and storage tanks are also periodically cleaned.

e. Laboratory-Derived Wastewater is generated from on-site laboratories which characterize incoming waste streams and monitor on-site treatment performance.

f. Contaminated storm water is storm water which comes in direct contact with landfill wastes, the waste handling and treatment areas, or wastewater that is subject to the limitations and standards. Some specific areas of a landfill that may produce contaminated storm water include (but are not limited to) the open face of an active landfill with exposed waste (no cover added), the areas around wastewater treatment operations, trucks, equipment or machinery that has been in direct contact with the waste, and waste dumping areas.

g. Non-contaminated storm water includes storm water which does not come in direct contact with landfill wastes, the waste handling and treatment areas, or wastewater that are subject to the limitations and standards. Non-contaminated storm water includes storm water which flows off the cap, cover, intermediate cover, daily cover, and/or final cover of the landfill.

EPA received extensive comments on its proposal to include contaminated storm water as a regulated waste stream under the landfills effluent guidelines. Several commenters stated that contaminated storm water (storm water that comes into contact with solid waste at the landfill site) should not be subject to the landfills effluent limitations guidelines because this is already covered by the Final National Pollutant Discharge Elimination System Storm Water Multi-sector General Permit (MSGP) for Industrial Activities (60 FR 50803).

The Storm Water Pollution Prevention Plan (SWPPP) required by the storm water MSGP or an authorized State's equivalent general permit requires landfill facilities to identify all of the sources of storm water contamination at the landfill and then implement measures and controls (such as good housekeeping for materials storage, sediment and erosion controls—particularly from intermediate and final covers) in an effort to prevent storm water contamination. EPA believes that the storm water MSGP (or an authorized State's equivalent general permit) adequately controls pollutants from storm water runoff from covered areas of the landfill.

Covered areas of the landfill include the following: capped, final cover, intermediate cover, and daily cover areas. The Agency believes that the SWPPP and the monitoring requirements in the storm water MSGP provide adequate controls for reducing the level of pollutants in storm water from these areas of landfills.

EPA recognizes that there may be some incidental contact with wastes when storm water flows over a daily or intermediate cover. However, EPA concluded that such contact will not lead to any meaningful “contamination” of the storm water so long as the landfill complies with the requirements of the storm water MSGP or an authorized State's equivalent general permit. For example, the Best Management Practices (BMPs) outlined in Table L-1 and L-2 of the storm water MSGP (60 FR 50940) and the monitoring requirements in Table L-5 and L-6 for TSS and total recoverable iron (60 FR 50943) provide adequate controls for the pollutants that would most likely be associated with runoff from covered areas of non-hazardous landfills.

Similarly, for hazardous landfills, BMPs and monitoring requirements outlined in Table K-2 (60 FR 50935) and Table K-3 (60 FR 50936), respectively, also require controls for pollutants associated with runoff from covered areas of a landfill. In EPA's

view, BMPs provide a fair degree of control of these pollutants and the monitoring requirements of the MSGP provide a tool for evaluating the effectiveness of the pollution prevention plan.

As part of the Agency's continuing effort to improve its environmental and pollution control programs, EPA has concluded that, although the MSGP provides some control for contaminated storm water runoff, the landfills effluent limitations guidelines provide a more comprehensive level of control for storm water runoff that has come in direct contact with solid waste, waste handling and treatment areas, or wastewater flows that are controlled under this rule. Although the storm water MSGP considered circumstances in which untreated leachate may be incidently commingled with storm water, the Agency explicitly acknowledged in the MSGP that insufficient data were available to establish numeric limits for storm water that might be contaminated based on best available technology for municipal solid waste landfills (MSWLFs) (60 FR 50942), non-hazardous industrial landfills (60 FR 50943), and hazardous landfills (60 FR 50935).

However, EPA has now concluded that the data collected in support of the landfills effluent limitations guidelines provide the basis for establishing appropriate numeric limitations for contaminated storm water. EPA specifically noted in the preamble for the storm water MSGP that it was developing these guidelines and that where the guidelines applied to discharges, facilities must comply with them. (60 FR 50942). In addition, EPA intends to propose a reissuance of the storm water MSGP which would include the promulgated landfills effluent limitations for contaminated storm water (as defined by these guidelines).

EPA fully explains its rationale for including contaminated storm water as a regulated wastewater for the landfills effluent guideline in the Comment Response document found in the Landfills Public Record.

h. Contaminated ground water is water below the land surface in the zone of saturation which has been contaminated by landfill leachate. For the final rule, EPA has not included within the scope of regulated flows ground water which has been contaminated by a landfill and is collected and discharged. The reasons for this decision are as follows.

During development of the rule, EPA considered whether it should also include contaminated ground water flows within the scope of this guideline. Historically, many landfill operations have caused the contamination of local ground water, mostly as a result of leakage from unlined landfill units in operation prior to the minimum technology standards for landfills established by RCRA Subtitle C and D regulations. Subsequently, State and Federal action under the Comprehensive Environmental Response Compensation and Liability Act (CERCLA) has required facilities to clean up contaminated ground water. In many cases this has resulted in the collection, treatment and discharge of treated ground water to surface waters. In addition, in the case of RCRA Subtitle C hazardous waste landfills and municipal solid waste landfills (MSWLFs), applicable regulatory standards require ground water monitoring and post-closure care and, in the event of ground water contamination, corrective action measures. These requirements may also result in treatment of contaminated ground water by such landfill facilities.

EPA evaluated flows, pollutant concentrations, treatment in place, and current treatment standards for discharges of contaminated ground water from landfills. From this evaluation, EPA concluded that pollutants in contaminated ground water flows are often very dilute or are treated to very low levels prior to discharge. EPA concluded that, whether as a result of corrective action measures taken pursuant to RCRA authority or State action to clean up contaminated landfill sites, landfill discharges of treated contaminated ground water are being adequately controlled. Consequently, further regulation under this rule would be redundant and unnecessary.

EPA is aware that there are landfill facilities that collect and treat both landfill leachate and contaminated ground water flows. In the case of such facilities, EPA has concluded that decisions regarding the appropriate discharge limits should be left to the judgment of the permit writer. As indicated above, contaminated ground water may be very dilute or may have characteristics similar in nature to leachate. In cases where the ground water is very dilute the Agency is concerned that contaminated ground water may be used as a dilution flow. In these cases, the permit writer should develop BPJ permit limits based on separate treatment and/or discharge of the ground water flows or develop BPT/BAT limits based on a flow-weighted building block approach in order to prevent dilution of the regulated leachate flows. However, in cases where the ground water may exhibit characteristics similar to leachate, commingled treatment is appropriate because it is more cost effective and environmentally beneficial than separate treatment. EPA recommends that the permit writer consider the characteristics of the contaminated ground water before making a determination if commingling ground water and leachate for treatment is appropriate. See Section [VIII].

i. Recovering Pumping Wells wastewater is generated as a result of the various ancillary operations associated with ground water pumping operations. These operations include construction and development, well maintenance, and well sampling (

i.e.,

purge water). The wastewater will have very similar characteristics to contaminated ground water. Therefore, for the same reasons that EPA did not include contaminated ground water as a regulated wastewater, these regulations do not apply to wastewater from recovering pumping well operations.

C. Subcategorization

EPA proposed to divide the landfills point source category into two subcategories and to develop different limitations and standards for RCRA Subtitle C landfills and RCRA Subtitle D landfills. After reviewing comments on the subcategorization approach, EPA decided to promulgate effluent limitations guidelines using the same subcategorization approach outlined in the proposed rule.

For today's final rule, EPA decided that a single set of effluent limitations were not appropriate for the landfills industry and thus EPA developed different limitations for subcategories within the industry. In reaching its decision that subcategorization is required, EPA considered various factors. In developing effluent limitation guidelines, the Clean Water Act (CWA) requires EPA to assess a number of factors, including manufacturing processes, products, the size and age of a site, water use, and wastewater characteristics. The landfills industry is not typical of many other industries regulated under the CWA. Therefore, EPA looked at additional factors specifically tailored to the characteristics of landfill operations in deciding what limitations were appropriate for landfills. The factors considered for subcategorization included RCRA classification, types of wastes received, wastewater characteristics, facility size, age, ownership status, location, economic impacts, treatment technology

employed, energy requirements, and non-water quality environmental impacts. Based on an evaluation of these factors, EPA determined that there was a notable distinction between wastewater associated with Subtitle C landfills and that from Subtitle D landfills. A wider range of toxic organic pollutants and higher concentration of metals were found at the Subtitle C landfills. Thus, the most significant differences observed in wastewater characteristics at landfills are directly related to the wastes received at the landfill, which, in turn, is most obviously linked to the landfill's RCRA status. Therefore, EPA concluded that the most appropriate basis for subcategorization is by landfill classification under RCRA.

Additionally, the Agency believes that this subcategorization approach has the virtue of being easiest to implement because it follows the same classification previously established under RCRA and currently in use (and widely understood) by permit writers and regulated entities. The Agency believes that any subcategorization at odds with existing RCRA classification approaches would potentially create unnecessary confusion to the regulated community.

Subpart A of 40 CFR Part 445, “RCRA Subtitle C Hazardous Waste Landfill Subcategory,” applies to wastewater discharges from a solid waste disposal facility subject to the criteria in 40 CFR Part 264 Subpart N—Standards for Owners and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities and 40 CFR Part 265 Subpart N—Interim Standards for Owners and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities. Hazardous waste landfills are subject to requirements outlined in 40 CFR Parts 264 and 265 that include the requirement to maintain a leachate collection and removal systems during the active life and post-closure period of the landfill. For a discussion of these criteria, see the preamble to the proposed landfill guideline at 63 FR 6426, 6430-31. (February 6, 1998).

Subpart B of 40 CFR Part 445, “RCRA Subtitle D Non-Hazardous Waste Landfill Subcategory,” applies to wastewater discharges from all landfills classified as RCRA Subtitle D non-hazardous landfills subject to either of the criteria established in 40 CFR Parts 257 (Criteria for Classification of Solid Waste Disposal Facilities and Practices) or 258 (Criteria for Municipal Solid Waste Landfills). For a discussion of these criteria, see the preamble to the proposed landfill guideline at 63 FR 6426, 6431-32. (February 6, 1998).

EPA received a number of comments requesting that EPA further subdivide Subtitle D landfill facilities according to the specific type of waste received. These commenters claimed that the differences in wastewater characteristics between municipal solid waste landfills and monofills warranted further subcategorization. In addition, a group representing utility ash monofills suggested EPA develop separate limitations for such landfills. The group asserted that the organic content in ash monofill wastewater was so low that it would not sustain biological treatment, which EPA used as the basis for BPT, BCT, BAT and NSPS limitations. EPA did consider subcategorizing the Non-Hazardous subcategory further but chose not to based on several factors explained in detail in Section [X]. EPA decided to include monofills in the Non-Hazardous subcategory and concluded that, based on the available raw wastewater data, such facilities can meet the BPT/BAT limitations using technologies that are available at costs no greater than those technologies EPA evaluated (and determined to be economically achievable) for the universe of Subtitle D facilities.

D. Profile of the Landfills Industry

At proposal, EPA stated that there were approximately 11,000 landfill facilities located throughout the country in 1992. EPA has determined that the vast majority of these facilities either closed prior to the enactment of Subtitle C or Subtitle D regulations or do not generate wastewater covered by this regulation. Based on survey responses, EPA believes that the final guidelines will affect 143 facilities.

In the case of landfills subject to regulation under Subtitle D, EPA projects that there are 143 stand-alone landfill facilities that discharge in-scope wastewater directly to receiving streams. EPA estimates that there are 756 stand-alone Subtitle D landfill facilities that collect in-scope wastewater but discharge indirectly to a POTW. These facilities will not be affected by this final rule because EPA is not establishing pretreatment standards for non-hazardous, Subtitle D landfills. EPA determined that these discharges did not generally pass through or interfere with POTW operations so as to require national pretreatment standards. There are an additional 338 Subtitle D facilities that collect in-scope wastewater but do not discharge to surface waters or to POTWs and are also not affected by today's rule. These facilities dispose of their wastewater by hauling off-site to a centralized waste treatment facility, evaporation, recirculation back to the landfill, or land application.

With respect to landfills subject to regulation under Subtitle C, EPA estimates that there are no hazardous stand-alone landfill facilities discharging directly to surface waters. It is possible, however, that EPA's data collection efforts did not identify an existing, stand-alone direct discharging hazardous landfill facility or that an indirect (or zero discharging), stand-alone hazardous landfill facility may become a direct discharger. Consequently, EPA is establishing effluent limitations for direct discharging hazardous landfills. EPA estimates that there are six stand-alone hazardous landfill facilities that discharge indirectly to POTWs. In response to comments on the proposal, EPA decided not to establish pretreatment standards for hazardous Subtitle C landfills again because it decided national standards were not required. EPA estimates that there are 139 hazardous landfills which collect in-scope wastewater but do not discharge wastewater to surface waters or to a POTW. Methods of wastewater disposal include hauling wastewater off-site to a centralized waste treatment facility, underground injection, and solidification. Additionally, EPA estimates that there are more than 150 industrial facilities which contain landfills but would be excluded from this regulation as a result of the factors discussed at Section [III.B].

E. Technology Basis for Final Rule

This section explains how EPA selected the technologies that form the basis for effluent limitations and standards being promulgated today for the Hazardous Landfill and Non-Hazardous Landfill subcategories. For both the proposed and final rule, EPA developed information to evaluate the performance of various systems for treating landfill wastewater. EPA's database consisted of daily effluent data collected from the Detailed Monitoring Questionnaire and EPA's Wastewater Sampling Program. (EPA's data gathering efforts are explained in detail in the preamble to the proposal at 63 FR 6433-35.)

EPA has revised the database since the proposal for a number of reasons. First, the regulatory status for some landfills in the database has changed. EPA excluded from the analysis landfills that were no longer considered in the scope of the rule (for example, some captive landfills). Second, some landfills in the database have changed discharge status. EPA had inadvertently included two landfill facilities as direct

dischargers in the analyses for the proposal when the facilities were actually indirect dischargers. Third, in the loadings reduction analysis for the proposed rule, EPA included removals of volatile organic compounds associated with biological treatment. However, for the final rule, EPA determined that removals of volatile organic compounds should not be included because the biological and chemical treatment options being considered did not provide treatment for the volatile compounds. Fourth, for the final rule, EPA also revised the long-term averages for several pollutants to reflect more accurately the pollutant removals achieved by the technology options. The Agency based these revisions on re-analysis of the dataset used for proposal.

The effluent limitations EPA is establishing today are based on well-designed, well-operated systems. EPA based the final limitations on treatment achieved by landfill facilities employing the selected technologies. A landfill operator may, however, use any wastewater treatment technology and/or waste management practices to meet the numerical wastewater discharge limitations.

1. Best Practicable Control Technology Currently Available (BPT)

In today's rulemaking, EPA is establishing BPT effluent limitations for the two discharge subcategories for the Landfills Point Source Category. The BPT effluent limitations promulgated today will control identified conventional, priority, and nonconventional pollutants when discharged from landfill facilities. For further discussion of the basis for the limitations, technologies selected, and the factors EPA considered in its decision, see the Technical Development Document and the preamble to the proposed rule at 63 FR 6441.

a. BPT Options Considered and Selected for the RCRA Subtitle D Landfills Subcategory.

The BPT options analyzed for today's final rule are identical to those evaluated for the proposal. In the Agency's engineering assessment, EPA first considered three technologies commonly in use by landfills and other industries as options for BPT. These technology options were chemical precipitation, biological treatment, and multimedia filtration.

For its evaluation of chemical precipitation, EPA collected raw wastewater and treated effluent data from several non-hazardous landfills employing this treatment. Based on this data, EPA removed chemical precipitation from further consideration as a BPT treatment option. While chemical precipitation is an effective treatment technology for the removal of metals, non-hazardous landfills typically have low concentrations of metals in treatment system influent wastewater. Observed metals concentrations were typically not found at levels that would inhibit biological treatment or that would be effectively removed by a chemical precipitation unit. Therefore, EPA considered only the following two options for BPT.

• Option I—Biological Treatment. EPA first assessed the pollutant removal performance of biological treatment. EPA selected this as Option I due to its effectiveness in removing the large organic loads commonly associated with leachate. BPT Option I consists of aerated equalization followed by biological treatment. EPA included various types of biological treatment such as activated sludge, aerated lagoons, and anaerobic and aerobic biological towers or fixed film reactors in calculating limits for this option. The Agency based the costs for Option I on the cost of aerated equalization followed by an extended aeration activated sludge system and clarification, including sludge dewatering. Approximately 30 percent of the direct discharging municipal solid waste landfills employed some form of biological treatment, and 13 percent had a combination of equalization and biological treatment.

• Option II—Biological Treatment and Multimedia Filtration. The second technology option considered for BPT treatment of non-hazardous landfill wastewater was aerated equalization and biological treatment as described in Option I, followed by multimedia filtration. Approximately 10 percent of the direct discharging municipal solid waste facilities used the technology described in Option II.

EPA is promulgating BPT effluent limitations for the Non-Hazardous Landfills subcategory based on Option II because of the demonstrated ability of biological treatment systems in controlling organic pollutants and the effectiveness of multimedia filtration in removing TSS. EPA is maintaining its decision at proposal to base BPT on Option II level of control. EPA's decision to base BPT limitations on Option II treatment reflects primarily two factors: (1) The degree of effluent reductions attainable and (2) the total cost of the treatment technologies in relation to the effluent reductions achieved.

No basis could be found for developing different BPT limitations based on age, size, process or other engineering factors. EPA responds to comments regarding the development of separate BPT limitations for monofills and BPT limitations based on the age of the landfill at Section [X].

EPA has selected Option II based on the comparison of the two options in terms of total costs of achieving the effluent reductions, pounds of pollutant removals, economic impacts, and general environmental effects of the reduced pollutant discharges. BPT Option II removed 142,000 more pounds of conventional pollutants than Option I. EPA estimated that Option I would have cost approximately $7.30 million per year (1998$, after-tax) while EPA estimated that Option II will cost only slightly more—$7.64 million per year (1998$, after-tax).

Finally, EPA also looked at the costs of all options to determine the economic impact that today's rule would have on the landfill industry. EPA's assessment showed that under either option there were significant economic impacts on only two facilities. Further discussion on the economic impact analysis can be found in Section [V] of today's notice.

EPA is today promulgating effluent limitations for the following pollutants under BPT for direct discharging non-hazardous landfills: BOD

5

, TSS, pH, ammonia, alpha terpineol, benzoic acid, p-cresol, phenol, and zinc (total).

b. BPT Technology Options Considered and Selected for the RCRA Subtitle C Landfill Subcategory.

EPA's survey of the hazardous landfills industry identified no in-scope landfill facilities that discharge directly to surface water. All of the hazardous landfills within the scope of today's rule are either indirect or zero/alternative dischargers. EPA consequently could not evaluate any treatment systems in place at direct discharging hazardous landfills for establishing BPT effluent limitations. Therefore, EPA relied on information and data from widely available treatment technologies in use at hazardous landfill facilities discharging indirectly and at non-hazardous landfills discharging directly—so-called “technology transfer.” EPA concluded that the technology in place at some indirect hazardous landfills is appropriate to use as the basis for regulation of direct dischargers because the pollutant profile of the leachate generated at hazardous waste landfills discharging directly would be similar in character to that from indirect discharge hazardous waste landfills.

For the final rule, EPA considered the following three potential technology options for establishing BPT effluent

limitations for the Hazardous Landfill subcategory:

• Option I—Aerated equalization followed by chemical precipitation with primary clarification and multimedia filtration.

• Option II—Aerated equalization followed by chemical precipitation with primary clarification, biological treatment with secondary clarification and multimedia filtration.

• Option III—Zero or alternative discharge.

EPA evaluated the same treatment options for establishing limitations that it had evaluated at proposal. As previously noted, in developing the proposed limitations, EPA relied, in part, on data from non-hazardous direct dischargers employing well-operated treatment systems. In the case of the proposed TSS limitations, EPA relied on data from two facilities that followed chemical precipitation and biological treatment with multimedia filtration. While the proposal did not specifically discuss filtration as a final treatment step, the Development Document for the proposal fully explained the treatment system, including multimedia filtration, in place at the two facilities used to develop the proposed TSS limitation.

EPA evaluated chemical precipitation as a treatment technology because of metals concentrations typically found in hazardous landfill leachate and the efficient metals removals achieved through chemical precipitation. EPA also evaluated biological treatment as an appropriate technology because of its ability to remove organic loads present in the leachate. The Agency also considered multimedia filtration to be an appropriate technology for consideration. In the first two options listed above, multimedia filters are effective in removing TSS that might remain after primary or secondary clarification. Finally, EPA considered a zero or alternative discharge option as a potential BPT requirement because a significant segment of the industry is currently not discharging wastewater to surface waters or to POTWs. The zero or alternative disposal option would require facilities to dispose of their wastewater in a manner that would not result in wastewater discharge to a surface water or a POTW.

EPA eliminated Option I from consideration because it did not control organic pollutants effectively. As was the case in the proposal, EPA also decided to eliminate Option III because, for the industry as a whole, zero or alternative discharge options are either not viable or the cost is wholly disproportionate to the pollutant reduction benefits and thus it is not “practicable.” Methods of achieving zero or alternative discharge currently in use by hazardous landfills are deep well injection, solidification, and contract hauling of wastewater to a Centralized Waste Treatment (CWT) facility or to a landfill wastewater treatment facility. Thirty seven facilities are estimated to inject landfill wastewater underground on-site; 103 facilities send their wastewater to a CWT or landfill treatment system; and one facility solidifies wastewater.

The commenters' submissions support EPA's decision to reject zero or alternative discharge as the technology basis for BPT (or BAT) limitations for hazardous landfills. While EPA supports the use of zero or alternative discharges particularly where it does not result in media transfer of pollutants, many of the available zero discharge options have identifiable shortcomings such as transfer of waste residuals to another media or the availability of an alternative disposal option only in certain geographic locations.

For example, one demonstrated alternative disposal option for large wastewater flows is underground injection. However, this is not considered a practically available option on a nationwide basis because it is not allowed in many geographic regions of the country where landfills may be located. These restrictions may preclude underground injection at a given landfill. In such circumstances, landfills would need to resort to contract hauling to a Centralized Waste Treatment (CWT) facility. Unless the CWT itself were a zero discharge facility, the ultimate result would be treatment and discharge to surface waters or a POTW following waste treatment that may be no more effective than that which could have been provided on-site. This might result in substantial transportation costs for the landfill and associated non-water quality, environmental impacts (e.g., truck emissions) resulting in no net reduction in the discharge of pollutants. EPA's survey demonstrated that only landfills with relatively low flows (under 500 gallons per day) currently contract haul their wastewater to a CWT. The costs of contract hauling are directly proportional to the volume of wastewater and distance over which it must be transported, generally making it excessively costly to send large wastewater flows to a CWT, particularly if it is not located nearby.

EPA evaluated the cost of requiring all hazardous landfills to achieve zero or alternative discharge status. For the purposes of costing, EPA assumed that a facility would have to contract haul wastewater off-site because it may be impossible to pursue other zero or alternative discharge options. EPA concluded that the cost of contract hauling off-site for high flow facilities was unreasonably high and disproportionate to the removals potentially achieved. In addition, EPA concluded that the wastewater shipped to a CWT will typically receive treatment equivalent to that promulgated today, and that zero/alternative discharge requirements would result in additional costs to discharge without greater removals for hazardous landfill wastewater.

Based on the characteristics of hazardous landfill leachate and on an evaluation of appropriate technology options, the Agency selected Option II (aerated equalization followed by chemical precipitation and biological treatment with secondary clarification followed by multimedia filtration) as BPT technology for the Hazardous subcategory. EPA's decision to base BPT limitations on Option II treatment reflects primarily two factors: (1) the degree of effluent reductions attainable and (2) the total cost of the treatment technologies in relation to the effluent reductions achieved.

Although EPA did not identify any existing hazardous landfill facilities that discharged directly to surface waters, EPA estimated the cost of treatment and pollutant removal for a medium-sized facility. EPA estimates that for a facility with a wastewater flow of 25,000 gallons per day, the selected technology option would result in the removal of over 200,000 pounds of pollutants at an annualized cost of $192,400. EPA has determined that the selected technology option costs are reasonable in light of the projected pollutant removals. Because EPA did not identify any existing hazardous landfill facilities that discharged directly to surface waters, EPA's compliance costs for BPT for this subcategory are zero.

As previously noted, EPA relied on data from both hazardous and non-hazardous facilities to develop the limitations for this subcategory. Because there are currently no hazardous landfills discharging directly, EPA used data from indirectly discharging facilities to develop the limitations.

EPA identified three Subtitle C landfills that discharge to POTWs. The wastewater flow from one of the three facilities was very small (less than 1,000 g.p.d.) and consisted of only gas collection condensate and required only minimal treatment (neutralization using ammonia) prior to discharge to the POTW. Consequently, EPA did not consider this facility as appropriate for

establishing BPT limitations. The two remaining facilities both had treatment systems in place that achieved very good pollutant reductions. The treatment at one facility consisted of equalization and chemical precipitation followed by activated sludge biological treatment with secondary clarification. The second facility utilized equalization followed by three “sequencing batch reactor” biological treatment units operated in parallel. The treatment systems in place at these indirect hazardous facilities achieved low effluent concentrations with average removals of 88 to 98 percent of organic toxic pollutants, and 55 to 80 percent of metal pollutants. Thus, EPA concluded that it should use both facilities in the development of the Hazardous subcategory BPT limitations for nonconventional and toxic pollutants.

However, for the ammonia, BOD

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, and TSS limitations, EPA concluded that establishing BPT limits based solely on two indirect discharging treatment systems was not appropriate because indirect dischargers often do not operate their treatment systems to achieve optimal control of these pollutants. In the case of BOD

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and TSS, POTWs do not often establish local standards because the POTWs install treatment designed specifically to treat these pollutants. In the case of ammonia, some POTWs do not establish standards because they have installed advanced treatment for ammonia control. Other POTWs may establish ammonia standards based on local water quality concerns. EPA supplemented the Hazardous subcategory data for these three pollutants with data from non-hazardous landfill facilities. For BOD

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, EPA used data from both of the Hazardous subcategory BPT facilities and the Non-Hazardous subcategory BPT facilities to calculate the limitations. Because neither of the Hazardous subcategory BPT facilities used a multimedia filter (which is part of the selected BPT Option), EPA based the TSS limitation on the two Non-Hazardous subcategory BPT facilities that employed multimedia filtration.

In the case of ammonia, EPA concluded that it was not appropriate to establish limits using the performance of only indirect discharging facilities because only one of these facilities in the Hazardous subcategory demonstrated good ammonia control. Many POTWs with advanced or tertiary treatment units for nutrient control may not establish stringent local limits for ammonia. Therefore, basing ammonia limits only on indirect discharging landfills may not appropriately reflect the effluent discharge concentration of ammonia achieved by well-operated direct discharging landfills. Since EPA considered only one indirectly discharging hazardous facility to be a good performer for the treatment of ammonia, EPA chose to supplement the hazardous data for this facility with data from two non-hazardous BPT facilities, one of which was a direct discharger.

2. Best Conventional Pollutant Control Technology (BCT)

In today's rule, EPA is establishing BCT effluent limitations guidelines equivalent to the BPT guidelines for the conventional pollutants for both subcategories. (For an explanation of how EPA determines BCT, see the preamble to the proposed rule at 63 FR 6442.) In developing BCT limits, EPA considered whether there are technologies that achieve greater removals of conventional pollutants than selected for BPT, and whether those technologies are cost-reasonable according to EPA's test. In each subcategory, EPA identified no technologies that can achieve greater removals of conventional pollutants than selected for BPT that are also cost-reasonable, and accordingly EPA is promulgating BCT effluent limitations equal to the BPT effluent limitations guidelines.

3. Best Available Technology Economically Achievable (BAT)

EPA today is establishing BAT effluent limitations for both subcategories in the Landfills Category based on the same technologies selected for BPT. The BAT effluent limitations promulgated today would control identified priority and nonconventional pollutants discharged from facilities. EPA finds that the selected technology options are economically achievable. EPA has not identified any more stringent treatment technology option which it considered to represent BAT level of control applicable to facilities in this industry.

a. Rationale for Setting BAT Equivalent to BPT for the Non-Hazardous Landfill Subcategory.

EPA evaluated reverse osmosis technology as a potential option for establishing BAT effluent limits more stringent than BPT for the control of toxic pollutants. The Agency selected reverse osmosis for evaluation because of its effective control of a wide variety of toxic pollutants in addition to controlling conventional and nonconventional parameters.

EPA evaluated BAT treatment options as an increment to the baseline treatment technology used to develop BPT limits. Therefore, the BAT Option III consisted of BPT Option II (biological treatment followed by multimedia filtration) followed by a single stage reverse osmosis unit.

After an assessment of costs and pollutant reductions associated with reverse osmosis, EPA has concluded that it should not establish BAT limits based on more stringent treatment technology than the BPT technology. EPA concluded that a biological system followed by multimedia filtration would remove the majority of toxic pollutants, leaving the single-stage reverse osmosis to treat the very low levels of pollutants that remained. In the Agency's analysis, BPT removed 170,000 pounds of toxic pollutants per year whereas BAT Option III (BPT followed by single-stage reverse osmosis) removed 172,000 pounds of toxic pollutants per year. As stated in the proposal, EPA's economic assessment showed that BAT Option III had significantly higher annual compliance costs than the other options evaluated and resulted in six additional facilities experiencing moderate economic impacts. (63 FR 6451).

In addition, establishment of BAT Option III would not result in effluent limitations significantly more stringent than those established under BPT, which is currently achieving very low long-term average (LTA) effluent concentrations. Therefore, the Agency questioned whether the small additional removal of pounds of toxic pollutants achieved by BAT Option III justified the large incremental cost for the reverse osmosis treatment system. It should be noted that reverse osmosis was much more effective at removing the often high quantities of dissolved metals such as iron, manganese and aluminum. These pollutants, however, are added to the wastewater in treatment chemicals to promote more effective precipitation and are not regulated. For this reason, EPA does not include them in the calculation of pounds of toxic pollutants and does not take credit for their subsequent removal .

Several commenters on the proposal supported EPA's decision to reject reverse osmosis as the selected technology option. While EPA rejected reverse osmosis as the basis for BAT limitations because it was very expensive and achieved very little additional removal of pollutant, other technical factors also supported this decision. EPA agrees with the commenters that there may be additional site-specific costs associated with the operation of reverse osmosis systems at landfills that it could not directly factor into its cost analysis. EPA found that it was difficult to evaluate potential operating and concentrate

disposal problems and the associated potential increase in the cost of operating a reverse osmosis system at a landfill. The fact that reverse osmosis is a technology that concentrates rather than destroys pollutants is an important consideration. These concentrates still need to be treated and disposed, and, as noted by one commenter, some states may not allow them to be recycled back into the landfill. Further, recirculation may inhibit rather than stimulate anaerobic decomposition of the landfilled wastes. While the sludges generated by chemical precipitation and biological treatment require minimal treatment prior to disposal, reverse osmosis concentrates may require additional costly treatment steps prior to final disposal.

b. Rationale for Setting BAT Equivalent to BPT for the Hazardous Landfill Subcategory.

As stated in the BPT analysis, EPA's survey of the hazardous landfills industry identified no in-scope respondents which were classified as direct dischargers. All of the hazardous landfills in the EPA survey were indirect or zero or alternative dischargers. Therefore, the Agency based BPT limitations on technology transfer and treatment systems in place for indirect dischargers in the Hazardous subcategory and on treatment systems in place for BPT facilities in the Non-Hazardous subcategory. In EPA's engineering assessment of possible BAT technologies for direct discharging hazardous facilities, EPA evaluated the same three potential technology options it had evaluated when it was developing BPT limitations for the Hazardous Landfill subcategory. EPA determined that it should establish BAT limits based on the same technology evaluated for BPT limits. The Agency finds that the selected technology is economically achievable. EPA has identified no other technologies that would represent BAT level of control for this industry.

As explained in the BPT analysis, EPA eliminated Option I (equalization, chemical precipitation, and multimedia filtration) from consideration because it did not control organic pollutants effectively. In addition, EPA concluded that zero or alternative discharge is not an available alternative treatment technology for this industry. As explained above, zero or alternative discharge is not broadly applicable to landfills or may result in the transfer of waste residuals to other media.

4. New Source Performance Standards (NSPS)

a. Introduction.

As previously noted, under Section 306 of the Act, new industrial direct dischargers must comply with standards which reflect the greatest degree of effluent reduction achievable through application of the best available demonstrated control technologies. Congress envisioned that new treatment systems could meet tighter controls than existing sources because of the opportunity to incorporate the most efficient processes and treatment systems into plant design. Therefore, Congress directed EPA, in establishing NSPS, to consider the best demonstrated process changes, in-plant controls, operating methods, and end-of-pipe treatment technologies that reduce pollution to the maximum extent feasible.

b. Rationale for Setting NSPS Equivalent to BPT/BCT/BAT for Both Subcategories.

Today, EPA is establishing New Source Performance Standards (NSPS) that would control the same conventional, priority, and nonconventional pollutants regulated by the BPT/BCT/BAT effluent limitations guidelines. The conventional treatment technologies used to control pollutants at existing facilities are fully applicable to new facilities. Furthermore, EPA has not identified any other technologies or combinations of technologies that are demonstrated for new sources that are different from those used to establish BPT/BCT/BAT for existing sources. In the proposed rule, EPA solicited comments and data on other technologies that may be appropriate for the treatment of landfill leachate from new sources. One commenter urged EPA to consider reverse osmosis as an appropriate technology for the treatment of leachate. While EPA acknowledges that reverse osmosis can treat landfill leachate to levels equivalent to and even lower than the BAT limitations promulgated today, EPA concluded that the reverse osmosis treatment system and the BAT treatment system achieved essentially the same removals because reverse osmosis did not remove significantly more pounds of toxic pollutants than the treatment option selected as BAT. Moreover, as previously explained, there may be potential operating and disposal problems associated with a reverse osmosis system. Therefore, EPA concluded that it should adopt NSPS limitations that are identical to those in each subcategory for BPT/BCT/BAT.

5. Pretreatment Standards For Existing Sources (PSES)

Section 307(b) of the Act requires EPA to promulgate pretreatment standards for pollutants that are not susceptible to treatment by POTWs or which would interfere with the operation of POTWs. After a thorough analysis of indirect discharging landfills in the EPA database, EPA has decided not to establish PSES for either subcategory in the Landfills Point Source Category. For the proposal, EPA proposed

not

to establish pretreatment standards for indirectly discharging landfills in the Non-Hazardous subcategory. However, for the Hazardous subcategory, EPA proposed effluent limitations and pretreatment standards for six pollutants. In response to its proposal, EPA received a number of comments supporting the decision not to propose pretreatment standards for Subtitle D landfills. In addition, a number of commenters suggested that EPA should also reconsider whether Subtitle C landfills require national categorical pretreatment standards. As a result of these comments, EPA took a second look at its data and determined that pretreatment standards were not necessary for the Landfills Point Source Category.

For both subcategories, EPA looked at a number of factors in deciding whether a pollutant was not susceptible to treatment at a POTW or would interfere with POTW operations—the predicate to establishment of pretreatment standards. First, EPA assessed the pollutant removals achieved at POTWs relative to those achieved by landfills using BAT treatment systems. Second, EPA estimated the quantity of pollutants likely to be discharged to receiving waters after POTW removals. Third, EPA studied whether any of the pollutants introduced to POTWs by landfills interfered with or were otherwise incompatible with POTW operations. EPA, in some cases, also looked at the costs and other economic impacts of pretreatment standards and the effluent reduction benefits in light of treatment systems currently in-place at POTWs. The result of EPA's evaluation showed that POTWs could adequately treat discharges of landfill pollutants. Therefore, EPA is not establishing pretreatment standards for either subcategory in this point source category.

As noted above, among the factors EPA considers before establishing pretreatment standards is whether the pollutants discharged by an industry pass through a POTW or interfere with the POTW operation or sludge disposal practices. One of the tools traditionally used by EPA in evaluating whether pollutants pass through a POTW, is a comparison of the percentage of a pollutant removed by POTWs with the percentage of the pollutant removed by discharging facilities applying BAT. In most cases, EPA has concluded that a

pollutant passes through the POTW when the median percentage removed nationwide by representative POTWs (those meeting secondary treatment requirements) is less than the median percentage removed by facilities complying with BAT effluent limitations guidelines for that pollutant. For a full explanation of how EPA performs its removal analysis, see Chapter 7 of the Technical Development Document.

In developing the final guidelines, EPA has made a number of modifications to its calculations of pollutant removal used to compare POTW operations with BAT treatment. These changes are explained in greater detail in this preamble as well as the Technical Development Document and EPA responses to individual comments received on the proposal. For example, the primary source of POTW percent removal data used for removal comparisons is an EPA document, “Fate of Priority Pollutants in Publicly Owned Treatment Works” (EPA 440/1-82/303) commonly referred to as the “50-POTW Study”. The 50-POTW Study presents data on 50 well-operated POTWs with secondary treatment in removing toxic pollutants. For its removal comparison for this guideline, EPA eliminated influent values that were close to the detection limit, thereby minimizing the possibility that low POTW removals might simply reflect low influent concentrations instead of being a true measure of treatment effectiveness.

After revising the database, EPA calculated POTW-specific percent removals for each pollutant based on its average influent and average effluent values. The POTW percent removal used for each pollutant for the comparison is the median value of all the POTW-specific percent removals for that pollutant. EPA then compared the median POTW percent removal to the median percent removal for the BAT option treatment technology in order to determine pass through.

a. Rationale for Not Promulgating PSES for the Non-Hazardous Landfill Subcategory.

The Agency today is not establishing pretreatment standards for existing sources (PSES) for the Non-hazardous Landfill Subcategory. The Agency decided not to establish PSES for this subcategory after an assessment of the effect of landfill leachate on receiving POTWs and the cost of pretreatment standards.

EPA looked at three measures of effects on POTWs: biological inhibition levels, contamination of POTW biosolids and a comparison of BAT and POTW removals. For the proposed rule, following procedures outlined above, the removal comparison suggested that one pollutant, ammonia, would pass through in the Non-Hazardous subcategory. However, EPA concluded that ammonia was susceptible to treatment and did not interfere with POTW operations. Therefore, the Agency did not propose to establish national pretreatment standards for ammonia.

Following the proposal, EPA reviewed the data available in the proposed record for both the POTW percent removal calculations and the BAT percent removal calculations and made a number of adjustments. For the proposal, EPA calculated the BAT percent removals using data from well-operated biological treatment facilities in EPA's database. However, some of these facilities did not pass the editing criteria for selection as a BPT/BAT facility. For the revised removal comparison, EPA calculated percent removals using data from only those seven facilities that passed the BPT/BAT editing criteria. In addition, in the proposal, EPA inadvertently neglected to use selected BAT facilities in the calculation of percent removals for several pollutants even though the data for the facility passed the editing criteria.

The result of this revised comparison of removal for the Non-Hazardous subcategory suggested that BAT removal would be greater than POTW removal for four pollutants: ammonia, benzoic acid, p-cresol, and phenol. However, as explained below, EPA concluded that these pollutants do not pass through or interfere with POTW operations on a national basis and therefore has not established national categorical pretreatment regulations for these pollutants. Moreover, as discussed later in this section, EPA notes that adoption of PSES would result in the removal of only a small quantity of pollutants, approximately 14 toxic pound equivalents per facility per year. Such a reduction is low relative to that seen in other categorical pretreatment standards promulgated by EPA. (See 64 FR 45077).

(i.) Pretreatment Standards for Ammonia.

EPA has decided not to establish ammonia pretreatment standards for several reasons. First, while EPA's removal comparison suggests that ammonia in landfill leachate is not as amenable to POTW treatment as to pretreatment, in reality, EPA has concluded that ammonia is susceptible to POTW treatment on a national basis. Further, landfill discharges will not result in POTW upsets or interfere with POTW operations. The record indicates that POTWs are not currently experiencing any difficulty in adequately treating ammonia discharges from Subtitle D landfills. No POTWs commenting on the proposal cited any persistent POTW upsets associated with landfill leachate discharges. Finally, EPA has determined that pretreatment standards for ammonia for landfill indirect dischargers would be extremely costly. In these circumstances, EPA has concluded that ammonia is susceptible to treatment by POTWs and national pretreatment standards are not required.

Ammonia Removals.

In the case of ammonia, the median BAT percent removal for the landfills industry is 99 percent compared to the median POTW percent removal which is 39 percent.

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This comparison suggests that ammonia is not susceptible to treatment at a POTW and passes through. However, as discussed below, most subtitle D landfills discharging to POTWs are discharging small quantities of leachate with an ammonia concentration comparable to that observed in raw sewage.

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For the proposed rule, EPA calculated the POTW percent removal for ammonia to be 60 percent. However, upon applying the revised data editing procedures to the 50-POTW Study, EPA has now determined that ammonia POTW percent removal is 39 percent.

EPA's data show that over 75 percent of indirectly discharging landfills discharge fewer than 10 pounds of ammonia per day at a concentration similar to that observed in raw sewage. Because many POTWs are designed and operated to treat ammonia (and other pollutants) in raw sewage, a POTW will adequately control landfill discharges of ammonia so long as the ammonia loadings to a POTW did not significantly differ from that typically observed. In those circumstances, ammonia will not pass through such POTWs.

Moreover, some POTWs have installed additional treatment to control ammonia. The data on POTW removal used for EPA's comparison does not reflect this fact. POTWs that have installed additional ammonia treatment (or modified existing treatment) typically achieve removals in excess of 95 percent—much higher than the 39 percent removal observed for the POTWs in the comparison analysis. Thus, ammonia does not pass through POTWs with nitrification even in cases where significant loadings of ammonia are discharged to a POTW.

In these circumstances, EPA has concluded ammonia at levels discharged by Subtitle D landfills is generally susceptible to POTW treatment. Therefore, EPA concluded that ammonia limits are best established

by local POTWs based on site specific conditions in accordance with the POTW's design treatment capacity and existing mass loadings.

Upset and Interference.

EPA also assessed the ammonia concentrations and loads received by POTWs from Subtitle D leachate discharges to evaluate potential upsets or interference with POTW treatment systems. EPA concluded that national pretreatment standards were not required to prevent interference with POTW operations.

In terms of landfill leachate ammonia concentrations discharged to POTWs, only one of the Subtitle D landfill facilities in EPA's database is currently discharging (

i.e.

after treatment, if treatment is in place) wastewater to a POTW which contains more than 105 mg/L of ammonia. The remainder of the indirect discharging Subtitle D landfills discharged an average concentration of 37 mg/L of ammonia to POTWs, with one-half of the facilities discharging less than 32 mg/L. Typical ammonia concentrations in raw domestic sewage range from 12 to 50 mg/L (“Operation of Municipal Wastewater Treatment Plants: Manual of Practice, Volume II,” Water Pollution Control Federation).

The one facility in EPA's database that was discharging more than 105 mg/L of ammonia to a POTW was discharging 1,018 mg/L of ammonia to a 114 MGD POTW which currently has ammonia control (nitrification) in place. EPA also received influent ammonia data from several POTWs that commented on the proposed rule. The average ammonia influent concentration to POTWs ranged from 14 mg/L to 35 mg/L with an average concentration of 17 mg/L. Therefore, with the exception of the one outlier, the average concentration of ammonia in leachate discharged to POTWs (37 mg/L) noted in EPA's data closely parallels POTW experience (35 mg/L). However, it should be noted that the upper ranges of leachate concentrations were higher than the upper ranges observed in domestic sewage. Nevertheless, in most instances, observed ammonia discharge levels to POTWs fall within a POTW's treatment capabilities. Thus, EPA determined that the vast majority of Subtitle D landfills are discharging ammonia to POTWs at levels comparable to that which POTWs in the ordinary course of operations receive and treat in raw domestic sewage.

No POTWs commenting on the proposal cited any specific incidents where POTW acceptance of landfill leachate containing high levels of ammonia caused persistent upsets at the POTW. The data are consistent with that supplied by commenters and further supported EPA's understanding prior to the proposal of no documented persistent problems at POTWs due to ammonia concentrations in landfill leachate.

EPA also analyzed the effects that ammonia concentrations found in landfill leachate can have on the biological treatment systems at POTWs. In this analysis, EPA compared the concentrations of ammonia found in leachate with the activated sludge biological minimum threshold toxicity value (or inhibition value). With respect to ammonia, the inhibition value for activated sludge systems is 480 mg/L (Guidance Manual on the Development and Implementation of Local Discharge Limitations Under the Pretreatment Program, Volume 1. EPA, November 1987). The average raw wastewater concentration of ammonia found in Subtitle D landfills in EPA's database was 199 mg/L for direct, indirect and zero dischargers. In addition, all of the average and median ammonia concentration values observed in the data submitted to EPA in comments were below the activated sludge inhibition value. EPA has consequently determined that ammonia does not represent a threat to biological treatment systems that would require establishment of pretreatment standards.

Effect on Receiving Streams.

Subsequent to the proposal, EPA evaluated total wastewater flows and loads of ammonia to receiving streams associated with non-hazardous landfill indirect dischargers (an estimated 756 facilities). EPA estimated that the non-hazardous landfill industry discharges 2.7 million pounds per year of ammonia to POTWs, which results in 1.6 million pounds per year being discharged to receiving streams, assuming that the POTWs have secondary treatment achieving 39 percent removal but do not have additional treatment for ammonia control. However, as mentioned above, EPA is aware that many POTWs have installed additional treatment specifically for the control of ammonia and typically achieve removals in excess of 95 percent. A review of EPA's 1996 Clean Water Needs Survey and its Permit Compliance System database indicates that approximately 20 percent of the POTWs in the U.S. employ some sort of ammonia control. Over 75 percent of the Subtitle D landfills in EPA's database discharge less than 10 pounds per day to the POTW (3,500 pounds/year), which results in discharging less than six pounds per day (2,100 pounds/year) to receiving streams, again assuming secondary treatment only and no additional POTW ammonia controls. In light of existing ammonia control in place at POTWs, actual discharges to receiving streams are likely to be even smaller.

Cost of Pretreatment Standards.

EPA has evaluated the economic costs of ammonia pretreatment standards. EPA's economic assessment of these options demonstrated very high removal costs with low associated pollutant removals. Given the high cost, EPA concluded that it is not appropriate to establish national pretreatment standards to address the limited circumstances in which POTW removal might not match BAT removal performance.

EPA evaluated the costs of pretreatment standards in terms of the toxic pound equivalents. Pounds-equivalent is a term used to describe a pound of pollutant weighted by its toxicity relative to copper. These weights are known as toxic weighting factors. The Agency calculates pounds-equivalents by multiplying the pounds of a pollutant discharged from a landfill by the toxic weighting factor for that pollutant. The use of pounds-equivalent reflects the fact that some pollutants are more toxic than others.

The first treatment option that EPA evaluated for pretreatment of ammonia from non-hazardous landfills is biological treatment. EPA evaluated PSES Option I equivalent to BPT/BAT Option I, which was equalization plus biological treatment. (EPA did not evaluate a multimedia filter for PSES because the levels of TSS in landfill leachate will be adequately controlled by a POTW.) This option had a total annualized cost of $34.6 million (1998 dollars). Biological treatment removed 10,650 pound-equivalents annually, or an average of 14 pound equivalents per facility per year. This represents a cost of removal of $1,900/lb-equivalents (1981 dollars) and represents the cost of removing all of the pound-equivalents removed, not just ammonia. If EPA took credit only for the pound-equivalents of ammonia removed, the annual removal cost for this option is $7,100/lb-equivalents (1981 dollars). Moreover, these calculations are based on the assumption that POTWs will only remove 39 percent of the ammonia discharged to it. If POTWs remove more ammonia than that assumed, then the cost of each pound of pollutant removed by the industrial user raises. Given the installation of additional ammonia controls at many POTWs, actual ammonia removal by POTWs will be greater than assumed.

The second technology option EPA evaluated for the control of ammonia is ammonia stripping with appropriate air pollution controls. However, according

to EPA's survey of the landfills industry, only two percent of survey respondents use this technology for the treatment of landfill leachate. In addition, air or steam stripping is more commonly used for treatment of wastewater containing concentrations of ammonia that are several orders of magnitude greater than those typically found in landfill wastewater. Therefore, EPA concluded that biological treatment systems are more appropriate for the treatment of the ammonia concentrations found in landfill leachate. In addition, air stripping for ammonia removal generally requires warm climates, and therefore this may not be a viable treatment option for all landfills located in the United States. In these circumstances, effluent levels associated with air stripping may not be attainable in all cases and thus not broadly available in the landfill industry. In addition, the air stripping option for the treatment of ammonia has an estimated annualized cost of $15.1 million (1998 dollars, pre-tax costs). The cost-effectiveness for this option is also high, $4,400/lb-equivalents (1981 dollars).

As explained above, EPA concluded that the vast majority of POTWs experience no difficulty in treating the ammonia loads received from landfill indirect dischargers and that as a result there is generally no pass through of ammonia from landfill leachate on a national basis. Moreover, the cost of pretreatment is not warranted by the limited circumstances where pretreatment

would

result in reduced ammonia to surface water. But there are POTWs without additional controls for ammonia that may not be equipped to handle landfill leachate ammonia discharges. Consequently, in the proposal, EPA requested comments on requiring ammonia pretreatment standards for those landfills discharging to POTWs that do not have ammonia controls in place. Several commenters supported no pretreatment standard because of their conclusion that ammonia loads from landfills made up an insignificant amount of the total ammonia loads discharged to POTWs. Others favored pretreatment standards because of smaller POTWs that do not employ nutrient removal systems. EPA, however, is not convinced that national ammonia pretreatment standards are warranted even where landfills are discharging to POTWs without ammonia controls given the high cost of pretreatment and current ammonia concentrations in landfill leachate discharged to POTWs that are generally consistent with values observed in raw sewage. Special ammonia situations are best addressed by the local POTW based on site specific conditions in accordance with the POTW's design treatment capacity and existing mass loadings.

All of these factors discussed above confirm EPA's decision not to establish national ammonia pretreatment standards. EPA has concluded that landfills typically discharge wastewater to POTWs containing ammonia concentrations that can be adequately treated by POTWs. Further, in cases where ammonia loading rates are at levels which may be of concern or where ammonia discharges are a water quality concern, POTWs retain the ability to establish local limits on ammonia.

(ii.) Pretreatment Standards for Benzoic Acid— Benzoic Acid Pass-through Analysis.

As stated above, for the proposal, benzoic acid was not one of the pollutants EPA determined would pass through. However, after the proposal, EPA reviewed the BAT facilities and the representative POTW facilities used for the removal comparison and determined that it had not used the appropriate editing rules. As a result of these revisions, the comparison showed that the median percent removal for benzoic acid at the landfills BAT facilities was 99 percent compared to the median POTW percent removal which was determined to be 81 percent. Because the 50-POTW database does not contain information on the percent removal of benzoic acid, EPA used the National Risk Management Research Laboratory database (formerly known as the Risk Reduction Engineering Laboratory (RREL) database) to estimate the percent removal. (For more information on EPA's use of the RREL database, see Chapter 7 of the Technical Development Document.)

Despite the difference in the BAT and POTW percent removals, further analysis of the data showed that both systems were achieving the same level of treatment of benzoic acid. That is, both the RREL database facilities representing POTWs and the landfills BAT facilities were treating benzoic acid down to non-detect levels (50 μg/L). Therefore, the smaller percent removal achieved by facilities in the RREL database (used to represent the POTW percent removal) is a function of lower influent concentrations at those facilities and is not necessarily indicative of inferior treatment at POTWs. EPA concluded that benzoic acid in these circumstances is susceptible to treatment at the POTW and does not pass through.

Benzoic acid loads discharged to POTWs.

In addition, EPA also evaluated the total flows and loads of benzoic acid discharged from non-hazardous landfills to POTWs. EPA compared the current discharge loads to the loads that would be anticipated after the implementation of pretreatment standards. As was explained above, EPA evaluated Option I (biological treatment) as the appropriate treatment technology and has analyzed the costs and benefits of pretreatment standards for the Non-Hazardous subcategory for this option. According to EPA's estimates, non-hazardous landfills currently discharge approximately 4,700 pounds of benzoic acid to POTWs per year resulting in an annual discharge of 900 pounds to receiving streams. PSES Option I (biological treatment) would reduce this annual discharge to receiving streams to 400 pounds per year. The average non-hazardous facility discharges only 6.4 pounds of benzoic acid annually (less than 0.02 pounds per day), and the median discharge is only 1.9 pounds per year. Furthermore, benzoic acid has a toxic weighting factor of only 0.0003. Therefore, for the entire indirect discharging non-hazardous landfills population (approximately 756 facilities), Option I would only remove an additional 0.16 pound-equivalents per year.

As a result of the above analysis, EPA determined that national pretreatment standards for benzoic acid are not necessary because benzoic acid is susceptible to treatment by POTWs. POTWs and landfill BAT facilities both treat benzoic acid down to non-detect levels. In addition, EPA determined that the pounds of benzoic acid currently being discharged by landfills are compatible with POTW treatment and that pretreatment standards would result in little further reduction of benzoic acid.

(iii.) Pretreatment Standards for p-cresol—p-Cresol Pass-through Analysis.

Like benzoic acid, p-cresol also did not pass-through POTWs according to EPA's pass-through analysis at proposal. However, the result of its revised removal comparison showed some difference in removal. The landfills median BAT percent removal for p-cresol is 99 percent, while the estimated median POTW percent removal is 68 percent. (Again, because the 50-POTW database does not contain percent removal data for p-cresol, EPA used the RREL database to determine POTW removal.)

p-Cresol concentrations and loads discharged to POTWs.

EPA also analyzed the flows and loads of p-cresol being discharged from non-hazardous

landfills to POTWs. According to EPA's estimates, non-hazardous landfills currently discharge approximately 2,730 pounds of p-cresol to POTWs per year resulting in an annual discharge of 870 pounds to receiving streams. PSES Option I (biological treatment) would reduce this discharge to receiving streams to 130 pounds/year. Furthermore, p-cresol has a toxic weighting factor of only 0.0024. Therefore, the implementation of Option I results in an additional reduction of only 3.0 pound-equivalents per year across the entire Subtitle D indirect discharge population. On average, non-hazardous landfill facilities discharge only 3.4 pounds of p-cresol annually (or 0.01 pounds per day), and the median discharge load is only 0.7 pounds per year.

Based on the data shown above, EPA concluded that the implementation of pretreatment standards for p-cresol would result in only minimal reductions in the pounds of p-cresol discharged to surface waters. In addition, p-cresol is found in non-hazardous landfill leachate at concentrations which will not cause upsets at POTWs nor should POTWs have difficulty effectively treating such concentrations. The median raw wastewater concentration for p-cresol at municipal landfills is 75 μg/L. This concentration is well below the Universal Treatment Standard (UTS) of 770 μg/L established for F039 wastes (multi-source leachate) in 40 CFR 268.48.

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EPA bases UTS on the Best Demonstrated Available Treatment Technology (BDAT) for each listed hazardous waste. BDAT represents the treatment technology that EPA concludes is the most effective for treating a particular waste that is also readily available to generators and treaters.

(iv.) Pretreatment Standards for Phenol.

(iv.) Pretreatment Standards for Phenol.

Although phenol appeared to pass through, EPA decided not to establish pretreatment standards for phenol based on the fact that phenol is highly biodegradable and is treated by POTWs to the same degree as the landfill direct dischargers. Furthermore, the Agency concluded that the differences in influent concentrations caused the apparent difference in removal performance between landfill direct dischargers and POTWs. As a result, the performance across the landfills direct dischargers showed higher removals than the performance at the POTWs.

In EPA's landfills database, raw wastewater concentrations of phenol at the BAT facilities in the Non-Hazardous subcategory were much higher than the influent concentrations at the POTWs used in the determination of the POTW percent removal. The average influent concentrations for phenol for the three non-hazardous BAT facilities used in the pass-through analysis ranged from 350 μg/L to 5,120 μg/L. All three of the facilities treated phenol down to the analytical minimum level (10 μg/L), corresponding to a median percent removal of 97.5 percent. For POTW performance, EPA used a total of eight POTWs in the analysis for POTW percent removal of phenol. The average influent concentration for phenol at these eight POTWs was 387 μg/L, and six of the eight effluent values were below the analytical minimum level and therefore assigned values of 10 μg/L. Thus, the average percent removal for the POTWs was 95.3 percent. In this case, EPA concluded that the differences in removals for POTWs (95.3 percent) and BAT facilities (97.5 percent) is an artifact of the differing influent concentrations and does not necessarily reflect a real difference in treatment performance. Therefore, EPA concluded that phenol is treated to essentially the same level by direct dischargers and POTWs and, therefore, does not pass through.

c. Technology Options Considered for PSES for Hazardous Landfill Subcategory.

In the proposed rule, EPA proposed pretreatment standards for six pollutants that EPA determined to pass through in the Hazardous subcategory. However, after reviewing the comments received and re-evaluating the pollutant loads in the Hazardous subcategory, EPA has decided not to establish national pretreatment standards for Subtitle C landfills.

As previously explained, EPA establishes pretreatment standards for pollutants that are not susceptible to treatment at a POTW or for pollutants that may interfere with POTW operations. As explained at Part 1.b. of this section, for the Hazardous subcategory, EPA identified only three Subtitle C landfills, all of them indirect dischargers. EPA used data from two of these hazardous landfills to develop the BPT/BAT limitations for toxic pollutants because these landfills were using the treatment systems for their leachate that EPA determined was the BPT/BAT treatment technology.

EPA also performed an analysis for this subcategory in order to compare POTW removals with BAT treatment systems. As was the case for the Non-Hazardous subcategory, EPA revised the pass-through analysis data editing procedures after the proposal and as a result EPA's removal results have changed. The result of the revised comparison show BAT removals greater than POTW removals for the following eight pollutants: ammonia, alpha-terpineol, aniline, benzoic acid, naphthalene, p-cresol, phenol, and pyridine. For its removal comparison for ammonia, EPA compared the nation-wide median percentage of ammonia removed by well-operated POTWs to the percentage of ammonia removed by BAT treatment systems from both the Hazardous and Non-Hazardous subcategories. (For the reasons explained at Part 1.b of this section, in the case of ammonia, EPA supplemented the Hazardous subcategory data with data from non-hazardous landfill facilities.) For all other toxic pollutants, in determining whether a pollutant would pass through a POTW, the Agency compared the nation-wide median percentage of a pollutant removed by well-operated POTWs with secondary treatment to the percentage of a pollutant removed by BAT treatment systems from only the Hazardous subcategory. For the proposal, EPA proposed pretreatment standards that were equivalent to the BPT/BAT limitations for the pollutants that passed through. EPA has reconsidered its decision that it should promulgate national pretreatment standards for hazardous landfills. The reasons for this decision are explained in more detail below.

Two of the indirect discharging landfills have treatment technology in place that EPA considers to be BAT, and currently discharge very low concentrations of pollutants to their local POTWs. The third and only other indirectly discharging Subtitle C landfill for which EPA has data discharged less than 1,000 gal/day of landfill gas collection condensate to a POTW. In addition to the low wastewater flow at this landfill, the facility has relatively low raw wastewater pollutant concentrations and employs neutralization with ammonia followed by settling prior to discharge to the POTW.

Several commenters on the proposal questioned EPA's rationale for developing ammonia pretreatment standards for the Hazardous subcategory while not establishing ammonia pretreatment standards for the Non-Hazardous subcategory. EPA's database indicate that the median raw wastewater ammonia concentration for hazardous landfills is 268 mg/L as compared to the raw wastewater ammonia concentration for Subtitle D landfills which is 199 mg/L.

6

EPA has current information on

ammonia concentration in wastewater discharges for two of the three Subtitle C landfills in EPA's database. One of the landfills employs biological treatment and discharges an average of 4.9 mg/L of ammonia to the POTW. The other landfill employs chemical precipitation prior to biological treatment and discharges ammonia at an average concentration of 156 mg/L. This discharge level presents no apparent problem to the receiving POTW. According to discussions with this facility and the POTW, the POTW has not set local pretreatment standards for ammonia for this landfill, and the POTW does not perform nitrification nor is there an ammonia limit in the POTW's NPDES permit. Since 1995, the POTW has seen the ammonia concentration at its headworks increase from 13 mg/L to 20 mg/L and has experienced some upsets at the POTW. However, the POTW explained that it was unsure whether the upsets are a result of the increased ammonia concentrations or due to some other constituent in the wastewater. In addition, the POTW is not sure if the landfill leachate discharge is contributing at all to the upsets. As was the case in the Non-hazardous subcategory, EPA concluded that national pretreatment standards for ammonia are not warranted by the small quantity of ammonia being discharged to POTWs from landfills in this subcategory and due to the site specific water quality and POTW nitrification issues associated with ammonia.

6

In the comments received on the proposal, some commenters referred to the Hazardous subcategory median ammonia raw wastewater concentration

referred to in Table 6-8 on page 6-44 of the Proposed Landfills Development Document (EPA-821-R-97-022). This table lists the median ammonia raw wastewater concentration of 8.6 mg/L. However, this median concentration included numerous CERCLA facilities with discharges that consisted primarily of ground water. After proposal, EPA recalculated the median ammonia raw wastewater concentration for the Hazardous subcategory using only data from Subtitle C landfills in EPA's database. This results in a median raw wastewater ammonia concentration of 268 mg/L.

Although the removal comparison suggests that phenol may pass through, EPA decided not to establish pretreatment standards for it because it is highly biodegradable and is, in fact, treated by POTWs to the same degree as the landfill direct dischargers. The Agency concluded that any apparent difference in removals in the removal comparison is an artifact of differing influent concentrations rather than any difference in performance between landfill direct dischargers and POTWs.

In EPA's landfills database, raw wastewater concentrations of phenol at the two BAT facilities in the Hazardous subcategory were much higher than the influent concentrations at the POTWs used in the determination of the POTW percent removal. The average influent concentrations for phenol for the two hazardous BAT facilities used in the pass-through analysis ranged from 5,120 μg/L to 98,500 μg/L, and the average effluent concentrations ranged from 10 μg/L to 814 μg/L corresponding to an average percent removal of 99.8 percent. For POTW performance, EPA used a total of eight POTWs in the analysis for POTW percent removal of phenol. The average influent concentration for phenol at these eight POTWs was 387 μg/L, and six of the eight effluent values were below the analytical minimum level and therefore assigned values of 10 μg/L. Thus, the average percent removal for the POTWs was 95.3 percent, and therefore EPA determined that the pollutant passed through. In this case, EPA concluded that the pass-through determination is an artifact of the differing influent concentrations and does not necessarily reflect a real difference in removals. Therefore, EPA concluded that phenol is treated to essentially the same level by direct dischargers and POTWs and, therefore, does not pass through.

Further review of the comparison for alpha-terpineol, aniline, benzoic acid, naphthalene, and pyridine under the revised analysis showed that all of these pollutants were treated down to non-detect levels in both the landfill's BAT treatment option and in the RREL facilities representing POTWs. That is, both BAT facilities and POTWs achieve the same level of treatment for these pollutants, and the differences in removal once again were simply a function of smaller influent concentrations at facilities representing POTWs. (Alpha-terpineol and benzoic acid are compounds for which a high removal efficiency would be expected at a POTW due to their relatively high biodegradability.) Therefore, the Agency determined that, not only are the current pollutant loads not a problem for POTWs, but also all of these pollutants are present in concentrations that are treated down to non-detect levels in a well-operated POTW. Thus, given the small loadings and low concentrations of these pollutants, EPA concluded that these five pollutants are susceptible to treatment at the POTW and do not pass through.

Furthermore, EPA has concluded that while the removal comparison suggests that two pollutants, naphthalene and aniline, may not be susceptible to POTW treatment, in fact, they will receive equivalent treatment. First, the median untreated wastewater concentration observed in EPA's data collection effort for these pollutants is less than the Universal Treatment Standards (UTS) EPA has developed for these pollutants in F039 wastes (multi-source leachate) in 40 CFR 268.48. The UTS for naphthalene is 0.059 mg/L which is slightly greater than the median concentration found in hazardous landfills (0.049 mg/L). The UTS standard for aniline is 0.81 mg/L while the median concentration in hazardous landfills is 0.237 mg/L. Second, aniline and naphthalene (as well as p-cresol and pyridine) will be removed from wastewater through attachment to the biosolids in the POTW's biological treatment system and then undergo subsequent biodegradation while entrained in the biosolids.

In addition, as noted above, the revised comparison shows a lower POTW removal for p-cresol than that achieved by BAT treatment. However, as was the case in the Non-Hazardous subcategory, EPA has concluded that the concentrations of p-cresol and the associated loadings discharged to POTWs from landfills in the Hazardous subcategory would be insignificant compared to the total loads received at the POTW. The median Subtitle C raw wastewater concentration for p-cresol is 144 μg/L (this includes only Subtitle C landfills and not the CERCLA data included in the median on page 6-44 of the Proposed Landfills Development Document) which is less than the UTS developed for p-cresol in F039 wastes which is 770 μg/L (40 CFR 268.48).

Therefore, based on the small quantity of pollutants involved and low pollutant concentrations discharged from landfills in the Hazardous subcategory, EPA concluded that national pretreatment standards for landfills in the Hazardous subcategory are unnecessary. In addition, EPA concluded that local limits are adequately controlling wastewater discharges from Subtitle C landfills.

6. Pretreatment Standards for New Sources (PSNS)

a. Introduction.

Section 307 of the Act requires EPA to promulgate both pretreatment standards for new sources (PSNS) and new source performance standards (NSPS). New indirect discharging facilities, like new direct discharging facilities, have the opportunity to incorporate the best available demonstrated technologies including: process changes, in-facility controls, and end-of-pipe treatment technologies.

b. Rationale for Setting PSNS Equivalent to PSES for Both Subcategories.

In today's rule, EPA has

decided not to establish pretreatment standards for new sources for both subcategories for many of the same reasons that EPA did not establish PSES limits. As stated in the PSES discussions above, EPA concluded that the typical concentrations of pollutants in landfill leachate are not at levels that will cause problems for POTWs. In addition, EPA determined that the relatively small wastewater flows from landfills coupled with the concentrations of pollutants typically found results in a small pollutant loading rate discharged to POTWs from landfills. Finally, in site-specific cases where a particular pollutant may be found at concentrations that are of concern to the POTW, EPA concluded that local pretreatment standards are the most appropriate means for controlling such discharges.

F. Development of Effluent Limitations

EPA based the final effluent limitations in today's notice on widely-recognized statistical procedures for calculating long-term averages and variability factors. The following presents a summary of the statistical methodology used in the calculation of effluent limitations.

EPA bases effluent limitations for each subcategory on a combination of long-term average effluent values and variability factors that account for variation in day-to-day treatment performance within a treatment plant. The long-term averages are average effluent concentrations that have been achieved by well-operated treatment systems using the processes described in the following section (Treatment Systems Selected for Basis of Regulation). The variability factors are the results of a calculation of the ratio of a high effluent value that would be expected to occur only rarely relative to long-term average effluent values. The purpose of the variability factor is to allow for normal variation in effluent concentrations. A facility that designs and operates its treatment system to achieve a long-term average on a consistent basis should be able to comply with the daily and monthly limitations in the course of normal operations.

EPA developed the variability factors and long-term averages from a data base composed of individual measurements on treated effluent. The Agency uses a combination of EPA sampling data and industry supplied data. While EPA sampling data reflect the performance of a system over a five day period, industry supplied data (collected through the Detailed Monitoring Questionnaire) reflect up to three years worth of monitoring data. EPA used a combination of EPA and industry supplied data whenever possible in order to better account for the variability of leachate over time. For further information on the calculation of effluent limitations, see Chapter 11 of the Technical Development Document.

G. Treatment Systems Selected for Basis of Regulation

1. Non-Hazardous Subcategory BPT Facility Selection

There were 46 in-scope landfill facilities in the EPA database that employed various forms of biological treatment considered for BPT/BAT for the Non-Hazardous subcategory. EPA evaluated these facilities selected as potential BPT/BAT candidates to determine the performance across the various types of biological treatment systems. In order to determine the best performers for biological treatment EPA established a number of criteria. The first criterion used in the selection of the best facilities was effective treatment of BOD

5

. Under this criterion, there were several reasons why a facility might be eliminated from the selection of BPT/BAT facilities. First, EPA required that both influent and effluent BOD

5

data be available so that the Agency could evaluate the effectiveness of the biological treatment system at the facility. In addition, EPA eliminated those facilities whose BOD

5

influent data were less than 100 mg/L because EPA did not consider the wastewater at these facilities to be representative of the landfills population as a whole. Because EPA based BPT/BAT limitations on the effectiveness of biological treatment, the Agency eliminated facilities that used additional forms of treatment (other than biological treatment) for BOD

5

removal. The final requirement for BPT/BAT selection in the Non-Hazardous landfill subcategory was that the biological treatment system at the facility had to achieve a BOD

5

effluent concentration less than 50 mg/L. EPA determined that facilities not able to maintain an effluent concentration below 50 mg/L were not operating their biological systems effectively.

After applying the criteria above, EPA identified seven facilities that met all of the BPT/BAT criteria. These seven facilities employed various types of biological treatment systems including activated sludge, a sequencing batch reactor, aerobic and anaerobic biological towers or fixed film, and aerated ponds or lagoons. Most of the facilities employed equalization tanks in addition to the biological treatment while several facilities also employed chemical precipitation and neutralization in their treatment systems. Clarification or sedimentation stages followed the biological treatment systems. EPA used data from all seven facilities employing well-operated biological treatment systems to calculate the effluent limitations for BOD

5

. (For those BPT facilities that employed both chemical precipitation as well as biological treatment, EPA determined that the biological treatment systems, and not the chemical precipitation systems, were removing the BOD

5

from the landfill wastewater. Therefore, EPA used these facilities for the calculation of BOD

5

limitations.) The average influent BOD

5

concentrations to these seven treatment systems ranged from 150 mg/L to 7,600 mg/L, and as mentioned above, all of the average effluent concentrations for these seven facilities were below 50 mg/L.

EPA used the data from the seven facilities identified as having good biological treatment systems to calculate the limits for additional pollutant parameters, including alpha terpineol, ammonia, benzoic acid, p-cresol, phenol, and zinc. Because one facility employed air stripping, EPA did not use its data for determining the limit for ammonia. In addition, EPA did not use facilities that operated chemical precipitation systems in addition to biological treatment for the calculation of the zinc limitation. Many of the facilities selected as BPT/BAT did not provide data for all the pollutants identified for regulation by EPA. In these cases, EPA based the effluent limitations on the BPT/BAT facilities for which data were available.

While the BOD

5

edits discussed above ensure good biological treatment and a basic level of TSS removal, treatment facilities meeting this level may not necessarily be operated for optimal control of TSS. To ensure that the effluent limitation developed for TSS reflects proper control, EPA established additional editing criteria for TSS. The primary factor in addition to achieving the BOD

5

criteria cited above was that the facility had to employ technology sufficient to ensure adequate control of TSS, that is, a sand or multimedia filtration system. The Agency eliminated facilities that used additional forms of treatment (other than a sand or multimedia filter) for TSS removal. The second factor EPA considered was whether the treatment system achieved an effluent TSS concentration less than or equal to 100 mg/L. EPA selected treatment facilities meeting these criteria as the average best existing performers for TSS. Two of the seven

BPT/BAT facilities employed a sand or multimedia filtration system and achieved an effluent TSS concentration far less than 100 mg/L. EPA used the TSS effluent data from these two facilities to calculate the TSS limitation for the Non-Hazardous subcategory.

2. Hazardous Subcategory BPT/BAT Facility Selection

As previously noted, EPA's statistical analysis of the facility identification and survey data suggests that there are no Subtitle C landfill facilities that discharge directly to navigable water and six that discharge to POTWs. However, EPA has specifically identified only three Subtitle C landfills that discharge to POTWs. EPA is transferring data from these facilities to establish BPT/BAT limitations. The wastewater flow from one of the three facilities was very small (less than 1,000 gallons per day) and consisted of only gas collection condensate and required only minimal treatment (neutralization using ammonia) prior to discharge to the POTW. Consequently, EPA did not consider this facility as appropriate for establishing BPT/BAT limitations. The two remaining facilities both had treatment systems in place that achieved very good pollutant reductions. The treatment at one facility consisted of equalization and chemical precipitation followed by activated sludge biological treatment. The second facility utilized equalization followed by three sequencing batch reactor biological treatment units operated in parallel. The treatment systems in place at these indirect hazardous facilities achieved low effluent concentrations with average removals of 88 to 98 percent of organic toxic pollutants, and 55 to 80 percent of metal pollutants. Thus, EPA concluded that it should use both facilities in the development of the Hazardous subcategory BPT/BAT limitations for nonconventional and toxic pollutants.

However, for the ammonia, BOD

5

, and TSS limitations, EPA concluded that establishing BPT/BAT limits based solely on two indirect discharging treatment systems was not appropriate because indirect dischargers often do not operate their treatment systems to achieve optimal control of these pollutants. In the case of BOD

5

and TSS, POTWs do not establish local standards because the POTWs install treatment designed specifically to treat these pollutants. In the case of ammonia, some POTWs do not establish standards because they have installed advanced treatment for ammonia control. Other POTWs may establish ammonia standards based on local water quality concerns. EPA supplemented the Hazardous subcategory data for these three pollutants with data from non-hazardous landfill facilities. For BOD

5

, EPA used data from both of the Hazardous subcategory BPT/BAT facilities and the Non-Hazardous subcategory BPT/BAT facilities to calculate the limitations. Because neither of the Hazardous subcategory BPT/BAT facilities used a multimedia filter, EPA based the TSS limitation on the two Non-Hazardous subcategory BPT/BAT facilities that employed multimedia filtration.

In the case of ammonia, EPA concluded that it was not appropriate to establish limits using the performance of only indirect discharging facilities because only one of these facilities in the Hazardous subcategory demonstrated good ammonia control. Many POTWs with advanced or tertiary treatment units for nutrient control may not establish stringent local limits for ammonia. Therefore, basing ammonia limits only on indirect discharging landfills may not appropriately reflect the effluent discharge concentration of ammonia achieved by well-operated direct discharging landfills. Since only one indirect discharging hazardous BPT/BAT facility achieved BPT/BAT ammonia removals, EPA chose to supplement the hazardous data with data from two non-hazardous BPT/BAT facilities, one of which was a direct discharger.

IV. Assessment of Costs and Impacts

A. Methodology for Estimating Costs and Pollutant Reductions Achieved by Treatment Technologies

The methodology EPA used for the final rule for estimating costs and pollutant reductions achieved by the various treatment technologies is the same as the methodology used by EPA for the proposal. However, there are differences in the estimated costs and pollutant reductions from the proposed rule. These differences are a result of several revisions EPA made when reviewing the costs and loads reductions after proposal. These changes are explained in detail in the Technical Development Document at Chapter 9.

The Agency calculated pollutant reductions for each of the questionnaire recipients that would potentially be subject to this rule and then modeled the national population by using statistically calculated survey weights. EPA estimated pollutant reductions by taking the difference in the current performance of the landfill industry and the expected performance after installation of the treatment technology. The Agency estimated pollutant reductions for each pollutant of interest at each questionnaire facility. EPA determined the current performance discharge concentrations from data supplied by the facility, or in cases where the facility did not supply current wastewater discharge data for a particular pollutant, the Agency based the current discharge concentration on data supplied from similar treatment systems at similar landfills. EPA determined the discharge concentrations expected to be achieved for a particular technology option from EPA sampling data or from industry supplied data at facilities selected as the best performers.

B. Costs of Compliance

The Agency has estimated the cost for landfill facilities to achieve the effluent limitations promulgated today. Table IV.B-1 summarizes the estimated costs and the Technical Development Document discusses them in more detail. All of the cost estimates in this section are expressed in terms of 1998 dollars.

The only costs associated with this final rule are for direct discharging landfills in the Non-Hazardous subcategory. EPA did not identify any commercial hazardous landfills in the United States that discharged directly to surface waters, and thus, the Agency did not estimate any costs of compliance for direct dischargers from hazardous landfills. In addition, there are no costs associated with PSES for either subcategory because the Agency is not establishing PSES for the Landfills Point Source Category.

Table IV. B-1.—Capital and Annual Costs of BPT

[In millions of 1998 dollars]

Subcategory

Number of facilities

Capital costs

Annual O&M costs

Non-Hazardous Direct Dischargers (BPT)

143

18.87

6.50

Hazardous Direct Dischargers (BPT)

0

0

0

C. Pollutant Reductions

The Agency estimated pollutant reductions for landfill facilities achieving each of the effluent limitations promulgated today. Table IV.C-1 summarizes the estimated reductions and the document “Environmental Assessment of Final Effluent Limitations and Standards for the Landfills Category” discusses them in more detail.

All of the pollutant reductions realized by this regulation are a result of the effluent limitations promulgated for direct dischargers in the Non-Hazardous subcategory. EPA did not identify any commercial hazardous landfills in the United States that discharged directly to surface waters, and thus, the Agency did not evaluate pollutant reductions for direct dischargers from hazardous landfills.

Furthermore, there are no pollutant reductions associated with PSES for either subcategory because the Agency is not establishing PSES limitations for the Landfills Point Source Category.

Table IV.C-1.—Pollutant Reductions Achieved by Implementing BPT

Subbcategory

Number of

facilities

Conventional pollutant

removals (pounds)

Toxic pollutant removals

(pounds)

Non-Hazardous Direct Dischargers (BPT)

143

600,000

323,150

Hazardous Direct Dischargers (BPT)

0

0

0

V. Economic Analysis

A. Introduction and Overview

This section summarizes EPA's analysis of the economic impacts of the final regulation. EPA describes the economic impact assessment in detail in the “Economic Analysis for the Final Effluent Limitations Guidelines and Standards for the Landfills Category” (hereafter “EA”). The EA estimates the economic effect on the industry of compliance with the regulation in terms of facility closures (severe impacts) and financial impacts short of closure (moderate impacts) for privately-owned landfill facilities. For publicly-owned landfill facilities, the report estimates financial impacts short of closure. The report also includes an analysis of the effects of the regulation on new landfill facilities and an assessment of the impacts on small businesses and other small entities.

EPA estimated the economic impacts of final regulatory options in each subcategory for BPT and NSPS. The technical evaluation and description of each option and the rationale for selecting the final option is discussed in Section [III] of today's notice. EPA has based its BPT/BCT/BAT limitations for the Non-Hazardous subcategory on technology Option II, which EPA estimates will have a total annualized cost of $ 7.64 million (1998$). (For privately-owned facilities, EPA evaluated costs in terms of after-tax costs.) Table V. A-1 summarizes the costs associated with the Option II.

Table V. A-1.—Total Costs of Selected Regulatory Option

[In millions of 1998 dollars]

Selected option for the non-hazardous landfill subcategory

Total

capital costs

Total

O & M costs

Post-tax total annualized costs

Option II

18.87

6.50

7.64

B. Summary of Economic Impacts

1. Cost Reasonableness and Economic Impacts of BPT

As discussed above in Section [II.A], in establishing BPT limitations, EPA considers the cost of the limitations in relation to the effluent reduction benefits achieved. EPA compares these costs and benefits by first calculating pre-tax total annualized costs and total removals of TSS and BOD

5

in pounds. EPA then compares the ratio of the costs to the removals for an option to the range of ratios in previous regulations to gauge the option's relative cost. Table V.B-1 presents the results of the cost and removal comparison. In the Non-Hazardous subcategory, Option II has a ratio of $ 14 per pound. Option II is within the historical bounds of BPT cost comparisons.

Table V. B-1.—BPT Cost Reasonableness Analysis

Selected option for the non-hazardous landfill subcategory

Pre-tax total annualized costs

(million 1998$)

Removals

(lbs)

Average cost reasonableness

(1998 $/lb)

II

8.57

598,579

14

EPA is promulgating BPT limitations based on Option II for both privately-and publicly-owned facilities. The impact analysis for Option II projects two facility closures as a result of compliance. The EA projects no additional economic impacts beyond these two severe impacts. The direct job losses associated with the projected closures are 20 Full Time Equivalent (FTE) positions. Table V.B-2 summarizes the economic impacts for BPT.

Table V. B-2.—Economic Impacts of BPT

Selected option for the non-hazardous landfill subcategory

Post-tax total annualized costs

(mil 1998$)

Severe

impacts

Moderate

impacts

Direct employment losses

(FTEs)

Option II

7.64

2

0

20

2. Economic Analysis of Final NSPS limitations

EPA is establishing NSPS limitations equivalent to the limitations that are established for BPT/BCT/BAT for the Non-Hazardous and Hazardous subcategories. In general, EPA believes that new sources will be able to comply at costs that are similar to or less than the costs for existing sources, because new sources can apply control technologies more efficiently than sources that need to retrofit for those technologies. EPA has determined that BPT/BCT/BAT limitations are economically achievable and, therefore, NSPS limitations will not present a barrier to entry for new facilities.

3. Firm Level Impacts

Firms differ from facilities in that firms are business entities or companies, which may operate at several physical locations. Facilities are individual establishments defined by their physical location, whether or not they constitute an independent business entity on their own. Some of the surveyed facilities are single-facility firms. In these cases, the firm-level impact depends only on the facility-level impact. In other cases, though, facilities are owned by multi-facility firms, so that the impact on the parent firm depends not only on that facility, but also on the impacts on and characteristics of other facilities owned by the same firm.

In this analysis, the test for significant adverse impacts on firms is whether firm-level compliance costs exceed five percent of firm revenues. Using this criterion, EPA finds no significant adverse impacts on affected firms and therefore determines that the effluent guideline will not impose unreasonable economic burdens on firms that own in-scope landfills.

4. Community Impacts

EPA assesses community impacts by estimating the expected change in employment in communities with landfills that are affected by the final regulation. Possible community employment effects include the employment losses in the facilities that are expected to close because of the regulation and the related employment losses in other businesses in the affected community. In addition to these estimated employment losses, employment may increase as a result of facilities' operation of treatment systems for regulatory compliance. It should be noted that job gains will mitigate community employment losses only if they occur in the same communities in which facility closures occur.

EPA projects that the final regulation will result in two post-compliance closures, with the direct loss of 20 Full-Time Equivalent (FTE) positions. EPA estimates secondary employment impacts based on multipliers that relate the change in employment in a directly affected industry to aggregate employment effects in linked industries and consumer businesses whose employment is affected by changes in the earnings and expenditures of the employees in the directly and indirectly affected industries.

The EA projects an estimated community impact of between 49 and 89 FTE losses as the result of the final rule. The direct and secondary job losses are not expected to be significant in terms of employment impacts to affected counties. EPA estimates that the regulation will result in employment gains of an additional 79 FTEs as a result of the operation of control equipment associated with treatment systems at landfill facilities.

5. Foreign Trade Impacts

EPA does not project any foreign trade impacts as a result of the effluent limitations guidelines. International trade in landfill services for the disposal of hazardous and nonhazardous wastes is virtually nonexistent.

VI. Water Quality Analysis and Environmental Benefits

A. Introduction

EPA evaluated the environmental benefits of controlling priority and nonconventional pollutant discharges to surface waters and publicly-owned treatment works (POTWs). Pollutant discharges into freshwater and estuarine ecosystems may alter aquatic habitats, adversely affect aquatic biota, and may adversely impact human health through the consumption of contaminated fish and water. Furthermore, pollutant discharges to a POTW may interfere with POTW operations by inhibiting biological treatment or by contaminating POTW biosolids.

Many pollutants commonly found in landfill wastewater have one or more toxic effects (

e.g.,

the pollutant may be a human health carcinogen or toxic to either some human system or to aquatic life). In addition, several of these pollutants bioaccumulate in aquatic organisms and persist in the environment.

The Agency's analysis focused on the effects of toxic pollutants but did not evaluate the effects of two conventional

pollutants and five nonconventional pollutants. The pollutants not assessed included total suspended solids (TSS), five-day biochemical oxygen demand (BOD

5

), chemical oxygen demand (COD), total dissolved solids (TDS), total organic carbon (TOC), hexane extractable material, and total phenolic compounds. Although the Agency is not able to monetize the benefits associated with reductions of non-toxic parameters, discharges of these parameters may have adverse effects on human health and the environment. For example, suspended particulate matter may degrade habitat by reducing light penetration and thus primary productivity and can alter benthic spawning grounds and feeding habitats by accumulation in streambeds. High COD and BOD

5

discharges may deplete oxygen levels, which can result in mortality or other adverse effects on fish.

B. Methodology Used for Estimating Water Quality Impacts and Benefits

A report prepared for this rule, “Environmental Assessment of the Final Effluent Guidelines for the Landfill Category,” presents the Agency's analyses of these environmental and human health risk concerns and of the water quality-related benefits resulting from the final effluent guidelines. This assessment both qualitatively and quantitatively evaluates the potential: (1) Ecological benefits; (2) human health benefits; and (3) economic productivity benefits of controlling discharges from direct discharging non-hazardous landfills based on site-specific analyses of current conditions and the conditions that would be achieved by compliance with the limitations being established today. EPA estimates in-stream pollutant concentrations from direct discharges using stream dilution modeling, and from these models, EPA estimates the potential impacts and benefits of the final rule.

EPA projects ecological benefits by comparing the steady-state in-stream pollutant concentrations, predicted after complete immediate mixing with no loss from the system, to EPA published water quality criteria guidance. Or, for those chemicals for which EPA has not published water quality criteria, EPA compares the steady-state in-stream pollutant concentrations to documented toxic effect levels (

i.e.,

lowest reported or estimated toxic concentration). In performing these analyses, EPA used guidance documents published by EPA that recommend numeric human health and aquatic life water quality criteria for numerous pollutants. States often consult these guidance documents when adopting water quality criteria as part of their water quality standards. However, because those State-adopted criteria may vary, EPA used the nationwide criteria guidance as the most representative value. EPA used the findings from the analysis of reduced occurrence of pollutant concentrations in excess of both aquatic life and human health criteria or toxic effect levels to assess improvements in recreational fishing habitats and, in turn, to estimate, if applicable, a monetary value for enhanced recreational fishing opportunities. EPA expects such benefits to manifest as increases in the value of the fishing experience per day fished or the number of days anglers subsequently choose to fish the cleaner waterways. These benefits, however, do not include all of the benefits that are associated with improvements in aquatic life, such as increased assimilation capacity of the receiving stream, improvements in taste and odor, or improvements to other recreational activities such as swimming and wildlife observation.

EPA projects human health benefits by: (1) comparing estimated in-stream concentrations to health-based water quality toxic effect levels or EPA published water quality criteria; and (2) estimating the potential reduction of carcinogenic risk and non-carcinogenic hazard from consuming contaminated fish or drinking water. EPA estimates upper-bound individual cancer risks, popula

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