Standards for the Management of Cement Kiln Dust

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 259, 261, 266, and 270

[FRL-6413-5 RIN 2050-AE34]

Standards for the Management of Cement Kiln Dust

AGENCY: Environmental Protection Agency.

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (``we'' or EPA) is today

proposing a creative, affordable, and common sense approach for the

management of cement kiln dust (CKD) waste under the Resource

Conservation and Recovery Act (RCRA). CKD would remain a non-hazardous

waste provided the following management standards are met. First, for

ground-water protection, the Agency is proposing management standards

which require a landfill to be designed to control releases of toxic

metals to ground water at the point of compliance. Second, to control

releases of fugitive dust, the proposed management standards would

require persons managing CKD waste to cover or otherwise manage the

landfill, CKD handling areas, and CKD storage areas to control wind

dispersal of fugitive CKD. Finally, this rule also proposes

concentration limitations on various pollutants in CKD used for

agricultural purposes. This rule also proposes RCRA Subtitle C

regulatory standards for CKD that is not managed according to the

management standards described above.

DATES: EPA will accept public comment on this proposed rule until

November 18, 1999.

ADDRESSES: Commenters must send an original and two copies of their

comments referencing docket number F-99-CKDP-FFFFF to: RCRA Docket

Information Center, Office of Solid Waste (5305G), U.S. Environmental

Protection Agency Headquarters (EPA, HQ), 401 M Street, SW.,

Washington, DC 20460. Hand deliveries of comments should be made to the

Arlington, VA, address below.

Comments may also be submitted electronically through the Internet

to: [email protected]. Comments in electronic format should also be

identified by the docket number F-99-CKDP-FFFFF. All electronic

comments must be submitted as an ASCII file avoiding the use of special

characters and any form of encryption.

Commenters should not submit electronically any confidential

business information (CBI). An original and two copies of CBI must be

submitted under separate cover to: RCRA CBI Document Control Officer,

Office of Solid Waste (5305W), U.S. EPA, 401 M Street, SW., Washington,

DC 20460.

Public comments and supporting materials are available for viewing

in the RCRA Docket Information Center (RIC), located at Crystal Gateway

I, First Floor, 1235 Jefferson Davis Highway, Arlington, VA. The RIC is

open from 9 a.m. to 4 p.m., Monday through Friday, excluding Federal

holidays. To review docket materials, it is recommended that the public

make an appointment by calling 703 603-9230. The public may copy a

maximum of 100 pages from any regulatory docket at no charge.

Additional copies cost $0.15/page. The index and some supporting

materials are available electronically. See the ``Supplementary

Information'' section for information on accessing them.

FOR FURTHER INFORMATION CONTACT: For general information, contact the

RCRA Hotline at 800 424-9346 or TDD 800 553-7672 (hearing impaired). In

the Washington, DC, metropolitan area, call 703 412-9810 or TDD 703

412-3323. For more detailed information on specific aspects of this

proposed rulemaking and regulatory decision, contact Bill Schoenborn,

U.S. EPA (5306W), 401 M Street, SW., Washington, DC 20460, (703) 308-

8483, or e-mail: [email protected].

SUPPLEMENTARY INFORMATION: The index and the following supporting

materials are available from the RCRA Information Center:

1. Report to Congress on Cement Kiln Dust (59 FR 709, January 6,

1994).

2. Regulatory Determination on Cement Kiln Dust (60 FR 7366,

February 7, 1995).

3. Notice of Data Availability: Additional Data Available on Wastes

Studied for the Report to Congress on Cement Kiln Dust; Request for

Comments. (59 FR 47133, September 14, 1994).

4. Correction to Notice of Data Availability (59 FR 51440, October

11, 1994).

The index and some of the supporting materials are available on the

Internet. Follow these instructions to access the information

electronically:

WWW: http://www.epa.gov/epaoswer/other/ckd/index.htm

FTP: ftp.epa.gov

Login: anonymous

Password: Your internet address

Files are located in /pub/epaoswer.

The official record for this action will be kept in paper form.

Accordingly, EPA will transfer all comments received electronically

into paper form and place them in the official record, which will also

include all comments submitted directly in writing. The official record

is the paper record maintained at the address in ADDRESSES at the

beginning of this document.

EPA responses to comments, whether the comments are written or

electronic, will be published in a notice in the Federal Register or in

a response to comments document placed in the official record for this

proposed rulemaking. EPA will not immediately reply to commenters

electronically other than to seek clarification of electronic comments

that may be garbled in transmission or during conversion to paper form,

as discussed above.

The contents of today's document are listed in the following

outline:

I. Statutory Authority

II. Background

A. Bevill Amendment

B. Report to Congress and Notice of Data Availability

C. Regulatory Determination and Subsequent Studies

1. Summary of Agency's Determination

2. Proposed Enforceable Agreement

3. The Need for CKD Management Standards

4. New Analyses

D. Beneficial Use of Cement Kiln Dust

III. Discussion of Options to Address Risks From Mismanaged CKD

A. State-Based Approach

B. Memorandum of Understanding

C. Two-Dust Approach

D. Develop Regulations Under Authority of Subtitle D

E. Subtitle C Enforcement Without Listing CKD

F. Tailored Standards Under Subtitle C

G. States Adopt Appropriate Programs

H. Today's Approach--Exclude Properly Managed CKD From Hazardous

Waste Listing

1. Develop Management Standards and Exempt Properly Managed CKD

From Classification as a Hazardous Waste (Management-based Listing)

2. Alternative Management-based Listing

3. Characteristic CKD

4. Apply Tailored RCRA Subtitle C Standards to Improperly

Managed CKD

IV. Proposed Management Standards

A. Protection of Ground-water Resources

1. The Need for Ground-water Protection Standards

2. Applicability

3. Location Standards

4. Performance-Based Standard for the Protection of Ground Water

5. Technology-Based Standards for the Protection of Ground Water

6. Requirements for Ground-water Monitoring

7. Corrective Action

B. Standards for Fugitive CKD Emissions

1. The Need to Limit Fugitive CKD Emissions

2. Applicability

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3. Performance Standard for the Protection of Air

4. Technology-Based Standards for Fugitive Dust Control

C. Closure

D. Post-Closure Care

E. Closure/Post-Closure Planning Requirements

F. Financial Assurance

G. Implementation

1. Notification, Recordkeeping, and Reporting

2. Permitting Requirements

H. Applicability of the Boilers and Industrial Furnaces Rule

I. Exemption from the Definition of Hazardous Waste

1. Waste-Derived Clinker

2. Light-Weight Aggregate Kiln Dust

3. Use of CKD in Removal and Remediation Actions

J. Final Rule Effective Date

V. Subtitle C Backup Standards

A. Subtitle C Requirements for Hazardous CKD Waste

1. 3004(x)--Special Characteristics

2. Facility-wide Corrective Action Requirement

3. Manifest, Recordkeeping, and Reporting Requirements

B. Implementation of Part 259 and RCRA Subtitle C Backup Standards

1. Enforcement

2. Removal of a Hazardous Waste Designation

3. Alternative Approach to Structuring the Performance Standards

VI. Standards for CKD Used as a Lime Substitute

A. Summary

B. CKD Agricultural Use Risk Assessment

1. Risk Assessment Methodology

2. Human Health Criteria and Effects

3. Agricultural Use Practice Assumptions

4. Fate and Transport of Chemical Constituents in the

Environment

5. Uptake of Contaminants in Plant and Animals

6. Receptor Scenarios and Exposure Pathways

7. Lead Risk Assessment

8. Ecological Risk and Phytotoxicity

9. Risk Assessment Results

C. Approach to Establishing Limiting Concentrations

1. Risk-based Approach--Proposed Limiting Concentrations for

Cadmium, Lead, and Thallium

2. Risk-Based Approach--Proposed Limiting Concentration for

Chlorinated Dioxins and Furans

3. Comparison to Agricultural Lime--Proposed Limiting

Concentration for Arsenic

4. Peer Review of the Risk Assessment

D. Implementation of Controls for the Agricultural Use of CKD

E. Alternative Standard to Limit Chlorinated Dioxins and Furans in

CKD

VII. Relationships Between this Action and Other Regulatory Programs

A. Stormwater Regulations

B. Clean Air Act

VIII. State Authority

A. Statutory Authority

B. Effect of Today's Proposed Rule

IX. Regulatory Requirements

A. Regulatory Impact Analysis Pursuant to Executive Order 12866

1. Scope and Approach for Estimating Economic Costs and Impacts

2. Summary of Cost and Impact Results

3. Benefits of the Rulemaking

B. Regulatory Flexibility Analysis

1. Identification of Small Cement Companies

2. Outreach

3. The Agency's RFA Screening Analysis

4. Agency Findings and Conclusions Regarding SBREFA Impacts

C. Environmental Justice--Applicability of Executive Order 12898

D. Protection of Children--Applicability of Executive Order 13045

E. National Technology Transfer and Advancement Act

F. Unfunded Mandates Reform Act

G. Paperwork Reduction Act

H. Executive Order 12875: Enhancing the Intergovernmental

Partnership

I. Executive Order 13084: Consultation and Coordination with Indian

Tribal Governments

Appendix I to the Preamble--Justification for CKD Listing

Appendix II to the Preamble--Reportable Quantities

I. Statutory Authority

Section 3001(b)(3)(C) of RCRA, as amended, required that, after

completing a Report to Congress (RTC) mandated by section 8002(o) of

RCRA, the EPA Administrator must determine whether Subtitle C

regulation of cement kiln dust (CKD) waste is warranted. The RTC

documenting EPA's study of CKD was signed by the Administrator on

December 30, 1993. EPA's regulatory determination was published in the

Federal Register on February 7, 1995 (60 FR 7366). To implement that

determination, EPA is today proposing rules using its authorities under

sections 2002(a), 3001(b)(3)(C) and 3004(x) of RCRA.

II. Background

On October 21, 1976, Congress enacted RCRA (Pub. L. 94-580).

Section 3001 of RCRA mandated that the EPA Administrator ``promulgate

regulations identifying characteristics of hazardous waste, and listing

particular hazardous wastes which shall be subject to the provisions of

this subtitle.'' Section 3004 required the Administrator to promulgate

standards applicable to owners and operators of hazardous waste

treatment, storage, and disposal facilities.

In response to these requirements, EPA proposed regulations for

managing hazardous wastes under Subtitle C of RCRA on December 18, 1978

(43 FR 58946). In this regulatory proposal, EPA proposed to defer most

of the RCRA Subtitle C requirements for six categories of wastes, which

it termed ``special wastes,'' until information could be gathered and

assessed and the most appropriate regulatory approach determined. The

special wastes were wastes typically generated in large volumes, and,

at the time were thought to possibly pose less risk to human health and

the environment than wastes being regulated as hazardous wastes. EPA

identified CKD waste as one of these ``special wastes.'' \1\

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\1\ The other five proposed ``special wastes'' specifically

identified in the 1978 proposed rule were mining waste; utility

waste; phosphate rock mining, benefication, and processing waste;

uranium waste; and oil and gas drilling muds and oil production

brines.

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A. Bevill Amendment

On October 12, 1980, Congress enacted the Solid Waste Disposal Act

Amendments of 1980 (Pub. L. 96-482), which added section

3001(b)(3)(A)(iii) (now frequently referred to as the Bevill Amendment)

to RCRA which, among other things, temporarily exempted ``cement kiln

dust waste'' (along with two other categories of waste) from Subtitle C

regulation, pending completion of certain studies. These amendments

also added section 8002(o), which required the Administrator to study

the adverse effects on human health and the environment, if any, from

the disposal of ``cement kiln dust waste,'' and submit a Report to

Congress on its findings. The 1980 amendments also added section

3001(b)(3)(C), which required the Administrator to make a regulatory

determination, within six months of the completion of the section

8002(o) study, whether or not to regulate CKD waste under Subtitle C of

RCRA.

In response to the 1980 RCRA amendments, on November 19, 1980, EPA

published an interim final amendment to its hazardous waste regulations

to reflect the provisions of the Bevill Amendment (45 FR 76618), which

is codified at 40 CFR 261.4(b)(8). Since that time, CKD has been exempt

from Subtitle C of RCRA--that is, this material has never been

regulated as a hazardous waste under Federal law.\2\

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\2\ It should be noted here that under the RCRA Subtitle C

Boilers and Industrial Furnaces (BIF) Rule, CKD generated by kilns

that burn hazardous waste as fuel may be ineligible for Bevill

Exclusion under certain conditions (see 40 CFR 266.112).

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B. Report to Congress and Notice of Data Availability

To comply with the Congressional mandate and to establish the

factual

[[Page 45634]]

basis for EPA decision making regarding the appropriate regulatory

status of CKD waste under RCRA, EPA published in December 1993 its

``Report to Congress on Cement Kiln Dust'' (RTC). In keeping with the

statutory requirements, the report addressed the following eight study

factors, as articulated at section 8002(o) of RCRA:

(1) The source and volumes of [CKD] generated per year;

(2) Present disposal practices;

(3) Potential danger, if any, to human health and the environment

from the disposal of (CKD);

(4) Documented cases in which danger to human health or the

environment has been proved;

(5) Alternatives to current disposal methods;

(6) The costs of such alternatives;

(7) The impact of those alternatives on the use of natural

resources; and

(8) The current and potential utilization of (CKD).

The RTC also included a review of applicable State and Federal

regulations, so regulatory decisions derived from the report would

avoid duplication of existing requirements.

In preparing the RTC, EPA developed industry-wide and, in some

cases, facility-specific data and analytical methods that reflect the

complexity of the issues addressed in the RTC. Facilities that generate

CKD waste vary considerably in size, location, operational aspects, and

waste management techniques. Moreover, to examine in detail the broad

array of study factors mandated by RCRA section 8002(o), EPA developed

approaches and methods that were sufficiently sophisticated to take

into account the special nature of CKD. The specific methods that EPA

used to address each of the study factors are described in detail in

Chapters 3 through 9 of the RTC. Additional information on the methods

used and supporting data are contained in the Background Documents to

the RTC available from the RIC as discussed above under the ADDRESSES

section.

In 1992 and 1993, the Agency visited 20 cement manufacturing

facilities in the U.S. and obtained samples of cement kiln dust

generated by each operation.\3\ The Agency conducted chemical analyses

on all of the samples for a number of constituents. The analytical

results were used in the development of the RTC, and they were included

in the Agency's RCRA docket that supports the report. Late in the

study, one final set of metals analyses were conducted on the cement

kiln dust samples as managed (e.g., stored, disposed) by six of the 20

facilities sampled. The Agency obtained the raw analytical data too

late for use in developing the RTC, but did include the data in the

RCRA docket for public inspection and comment.\4\

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\3\ The CKD sampling trip reports can be found in the RIC under

the following numbers: Phase I sampling trip reports (Nos. F-94-

RCKA-S0001 to S0066); Phase II CKD sampling trip reports (Nos. F-94-

RCKA-S0067 to S0073).

\4\ All of the analytical data on CKD can be found in the

Technical Background Document: Analysis of CKD Generation and

Characteristics Data, RIC docket Nos. F-94-RC2A-S0017 to S0017.G.

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After issuance of the RTC, the raw data were subjected to data

validation and the analytical results were finalized. Although not used

in the development of the RTC, the Agency did consider these data in

the process of formulating the CKD regulatory determination.

Accordingly, on September 30, 1994, EPA published a Notice of Data

Availability (NODA) (see 59 FR 47133) announcing the availability of

the additional analytical data. On October 11, 1994 (59 FR 51440), the

Agency published a Correction Notice which identified certain errors

and corrected certain portions of the new data pertinent to additional

assessments of potential risk from CKD waste.\5\

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\5\ Additional data on CKD waste studied in the Report to

Congress, including supplemental errata, is available in the RIC

docket under the general identification number F-94-RC2A-FFFFF.

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C. Regulatory Determination and Subsequent Studies

1. Summary of Agency's Determination

On February 7, 1995, EPA issued the determination required by

section 3001(b)(3)(C) of RCRA, finding that additional control of CKD

was warranted (60 FR 7366). The Agency stated that its concerns about

the potential harm to human health and the environment posed by some

CKD suggest the need for some level of regulation under RCRA Subtitle C

authority. The Agency also recognized that certain of these areas of

concern (those related to releases to surface waters) are more

appropriately controlled under other EPA-administered statutes. In

order to avoid unnecessary duplication among regulatory programs, EPA

stated it would rather use the other existing regulatory programs to

control risks where appropriate, and develop a more creative,

affordable, and common sense approach that would control the adverse

effects of CKD.

The Agency decided to develop, promulgate, and implement

regulations for CKD as necessary to protect human health and the

environment by using a variety of statutes. For surface waters, the

Agency believes that existing regulations and the planned general

permit under the National Pollutant Discharge Elimination System

(NPDES) permitting program provide an adequate mechanism for

controlling point source discharges and for managing storm water that

contains CKD. With respect to ground water, the Agency decided to use

its authority under RCRA Subtitle C provided by sections 2002(a),

3001(b)(3)(C), and 3004(x) to develop a program tailored to local

cement plant conditions to control specific risks. In the regulatory

determination, EPA also stated that it would develop and implement

additional controls under the Clean Air Act (CAA), as necessary to

address concerns relating to air emissions of CKD. Subsequently,

however, EPA has concluded that RCRA authorities will better serve that

purpose. EPA's reasons for changing its approach are discussed in

detail in Section VII. B. (Clean Air Act) below.

For most off-site beneficial uses of CKD (e.g., in waste

stabilization or certain construction uses), EPA's current record

indicates there are no significant risks. However, the Agency also

decided to evaluate the need for additional controls for a limited

number of off-site uses of CKD (such as use as a substitute for lime

fertilizer on agricultural fields) in its regulatory proposal. The

Agency stated that its focus would be restricted to those off-site uses

for which there may be significant risks.

EPA also stated in the regulatory determination that specific RCRA

Subtitle C components deserve particular scrutiny in developing a

tailored approach, including the following: facility-wide corrective

action under section 3004(u); land disposal restrictions requirements

(LDRs) under sections 3004(c),(d),(e),(f) and (g); minimum technology

standards under section 3004(o); and permit requirements under section

3005. EPA stated that most of the concerns traditionally addressed by

the land disposal restrictions program, permit requirements, and the

minimum technology standards would be best addressed through management

standards developed specifically for CKD.

2. Proposed Enforceable Agreement

On March 22, 1995, the U.S. cement industry, through the American

Portland Cement Alliance (APCA), submitted to the Agency a voluntary

management program for CKD. This program was based on earlier work APCA

submitted to EPA in 1993. Under this voluntary program, cement

[[Page 45635]]

manufacturing facilities would manage their CKD according to industry-

developed management standards, and EPA would enforce those standards

through a contract rather than through regulation. The proposed

agreement included provisions for compliance standards, facility waste

management plans, a public participation process, enforcement, and

penalties. The industry indicated that its intent was to provide the

Agency with a constructive alternative to Subtitle C regulation that

would not stigmatize CKD as hazardous waste.

The proposed enforceable contract represented a new approach and

raised a number of legal and technical issues which EPA evaluated. The

Agency also contacted various State agencies, industry groups, and

public citizen groups to assess their positions on the proposal.

Although EPA in the past has entered into unenforceable ``voluntary''

agreements with other industries, the Agency has determined that it

does not have inherent contract authority to enter into enforceable

agreements, although it has authority to enter into enforceable consent

orders under the imminent hazard provisions of RCRA section 7003, or

section 106 of the Comprehensive Environmental Response, Compensation,

and Liability Act of 1980 (CERCLA). The cement industry chose not to

pursue enforceable agreements under these authorities because of

concern that it would be inappropriate to characterize CKD as posing an

imminent and substantial danger to human health and the environment.

3. The Need for CKD Management Standards

In the RTC, the Agency described the decision rationale used to

make its regulatory determination. The Agency applied a step-wise

approach that it considered to be consistent with Congressional intent

that EPA consider all of the study factors listed in RCRA section

8002(o). The methodology used by EPA examined the need for CKD

management standards and the economic consequences of imposing full

Subtitle C requirements on the industry. (See 60 FR 7366 for a

discussion of the steps EPA considered in determining the need for CKD

management standards.)

a. Documented Evidence of Damage

The Agency determined that the potential exists for hazardous

constituents, including metals, to migrate from CKD waste sites and

that CKD has caused documented impacts (and may continue to cause

impacts) at levels of concern. Information is available to indicate

that ground water has been affected by CKD management units. During the

development of the RTC, the Agency identified five cases of damage to

ground water, 10 cases of damage to surface water and 21 cases of

damage to air from CKD waste management units.\6\ Two additional cases

of ground water damage, two additional cases of surface water damage,

and 16 additional cases of air damage were subsequently identified in

the 1994 NODA and placed in the RCRA docket in a technical background

document entitled Additional Documented and Potential Damages From the

Management of Cement Kiln Dust (See 59 FR 47133, September 14,

1994).\7\ In its Regulatory Determination, EPA stated these cases

suggest that despite State regulations damages continued to occur with

current (i.e., as of 1994) CKD management practices.

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\6\ Based on subsequent review of the damage cases, except for

two reassessments (one air damage case and one surface water damage

case), the Agency believes the information received in comment does

not contradict the Agency's basic conclusions regarding any of the

damage cases identified in the RTC and subsequent NODA. A detailed

description of these damage cases is available in Chapter 5 of the

RTC.

\7\ RIC Docket Nos. F-94-RC2A-S0003 to S0015.

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Typically, ground-water damages were the result of metals

constituents leaching into ground water from unlined CKD landfills and

waste piles. Ground-water damages were of concern to the Agency because

relatively few (17% in 1991) of all CKD management units had ground-

water monitoring systems, while 25 of 91 cement manufacturing

facilities were reported in 1991 to be located within one mile of a

public drinking water well. Additionally, ground-water damage was a

major factor cited for including two CKD disposal units on the CERCLA

(Superfund) National Priorities List (NPL).

Damages to air were also identified due to particulate emissions of

CKD from quarries, haul roads, and CKD handling equipment. Most of

these cases involved visible emissions violations (opacity) related to

equipment malfunctions associated with CKD handling equipment (kilns,

baghouses, and screw conveyors). In the regulatory determination, EPA

characterized the air releases as persistent, with many facilities

having more than one violation. Also, significant releases of airborne

particulates were frequently observed first-hand by Agency staff during

the course of the RTC study.\8\

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\8\ A general description of these emissions can be found in the

EPA CKD sampling trip reports which are located in the support

section of the RIC docket on the Report to Congress.

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b. Potential Risks to Human Health and the Environment

The Agency conducted a series of risk screening and site-specific

risk modeling studies to evaluate potential risks from on-site

management and off-site uses of CKD. Methodologies and results of these

studies were documented in Chapter 6 of the RTC and its related

technical background documents and in two subsequent EPA technical

background documents entitled Human Health and Environmental Risk

Assessment in Support of the Regulatory Determination on Cement Kiln

Dust (August 31, 1994) and Supplemental Errata Document for the

Technical Background Document for the Notice of Data Availability on

Cement Kiln Dust (September 30, 1994).\9\

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\9\ These documents are available in the RIC docket (Nos. F-94-

RCKA-FFFFF, F-94-RC2A-S0019 and -S0019.A).

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EPA assessed the risks of potential releases of CKD contaminants to

the environment, both during the routine management of the dust at

cement plants and during beneficial use of the dust at other locations.

The risk assessment was intended to complement the damage case study,

which provided actual instances of environmental contamination,

sometimes attributable to management practices and facility settings

not considered in the risk assessment. The risk assessment was also

intended to cover the potential for certain more subtle or long-term

risks that might not be evidenced in the damage case files.

One of the primary objectives of the risk assessment was to

evaluate, as realistically as possible, the baseline risks of CKD

management practices at actual sites. This was accomplished by focusing

initially on a sample of case-study cement plants and off-site

beneficial use scenarios that appeared to provide a reasonable

representation of the universe of sites where CKD is disposed and used.

For each sample site, EPA evaluated the potential for CKD contaminants

to be released into the environment, migrate to possible human and

ecological receptors through a number of media and pathways (e.g.,

ground water contamination, surface water runoff to streams or lakes,

windblown dust) and result in exposures and adverse effects. This

evaluation included a combination of qualitative analyses designed to

document and describe major factors contributing to (or limiting)

risks, and quantitative modeling designed to

[[Page 45636]]

estimate the magnitude of risks. The analysis conducted for the RTC was

then expanded to incorporate significant new information collected

after the RTC was published. This expanded analysis, which is

documented in EPA's technical background document supporting the

Agency's 1995 Regulatory Determination enabled EPA to characterize risk

levels for each pathway at each plant for the facilities evaluated.

The Agency's analysis indicates that there are potential risks

warranting concern, from both current on-site waste management

practices and certain off-site beneficial uses. Based on these

analyses, EPA predicted only low or negligible risk potential from on-

site management of CKD via direct exposure pathways (e.g., ingestion of

drinking water) . The Agency did find potential risk to human health

via indirect (i.e., foodchain) exposure pathways, however. Potential

risks from exposure to particulate matter were also indicated.

The Agency modeled health risks via indirect food-chain pathways

(i.e., risks from ingestion of contaminated crops, livestock, or fish).

These contaminants reach food products via movement of stormwater run-

off and/or windblown dust from uncontrolled CKD storage or disposal

areas to nearby water bodies and farm fields. EPA's foodchain pathway

analysis estimated potential individual cancer risks from 1 x

10-5 (1 in 100,000) to 1 x 10-3 (1 in 1,000)

for highly exposed subsistence fishers and farmers. Cancer risks of

concern were due primarily to exposure to arsenic in CKD. Similar

cancer risk levels due to dioxins are also possible at some additional

sites. However, the Agency's data base on dioxin levels in CKD was not

extensive enough to conduct a large scale study. EPA's risk modeling

also estimated potential exceedances of non-cancer hazard thresholds

via indirect exposure to the toxic metals cadmium, chromium, thallium

and lead, which are present in CKD.

Finally, EPA's CKD analysis indicated potential human health risks

due to exposure to the fine particulate matter (PM) which characterizes

CKD. Based on the Agency's analysis, windblown dust (PM less than 10

microns in size) from uncontrolled CKD waste management units could

exceed EPA's health-based fine particulate National Ambient Air Quality

Standard (NAAQS) at plant boundaries and potentially at nearby

residences. Further analysis of potential exposure to airborne PM from

cement kiln dust waste management units was conducted as part of EPA's

population risk assessment. This analysis also indicates that persons

living around cement plants may be exposed to airborne PM

concentrations in excess of the NAAQS. An overview of the population

risk assessment is provided in Section II.C.4.a. of this preamble. A

detailed description of that analysis is provided in the technical

background document on population risk assessment.

As previously noted, the Agency predicted a negligible impact to

ground water and consequently low or negligible risk to human health

via ingestion of contaminated drinking water. However, a large

percentage of cement plants (and CKD management units at those cement

plants) are located in areas of karst terrain, 10 many of

which may be underlain by bedrock with hydrological characteristics

conducive to leachate transport to off-site locations with limited

filtration, adsorption, and dilution. For reasons discussed in the

regulatory determination, the Agency determined that its ground-water

model is not suitable for modeling in karst terrain. The Agency has

evidence of ground-water contamination at each facility where ground-

water data were available, and thus conducted additional analyses of

ground-water transport.

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\10\ Karst terrains are defined in this proposal at 40 CFR

259.16(b)(1) as areas where karst landscape, with its characteristic

hydrogeology and/or landforms are developed.

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The Agency conducted two additional ground-water analyses to

evaluate the potential for ground water transport at CKD management

facilities. In the first analysis, the Agency evaluated whether the

choice of ground water models significantly influenced the results. In

this analysis, the Agency used EPA's Composite Model for Leachate

Migration with Transformation Products (EPACMTP) with the same

parameters used in the modeling to support the Report to Congress. The

Agency concluded that the choice of models did not significantly

influence the conclusions on ground water transport. In the second

analysis, the Agency parameterized the thermodynamic isotherms to

reflect the major ions likely to be present in CKD and the typical pHs

found in CKD. Based on this analysis, the Agency concluded that the

composition of CKD leachate may make metals more mobile. These analyses

are discussed in Section II.C.4.b, Additional Ground Water Modeling.

The Agency's initial risk assessment for off-site beneficial uses

of CKD indicated that most off-site uses do not pose significant risks.

Direct cropland application, however, occurs at a number of locations

in the country. Screening level analyses of agricultural use described

in the RTC and NODA suggest that some CKD, at plausible application

rates, contains sufficiently high concentrations of metals and dioxins

to cause food chain risks. Based on these initial findings, EPA

conducted a more detailed analysis of potential risks from use of CKD

as an agricultural liming agent. A summary description of the

agricultural use analysis and results of that analysis are presented in

Section VI.--Standards for CKD Used as a Lime Substitute.

c. Waste Characteristics

While CKD itself does not exhibit the RCRA Subtitle C hazardous

waste characteristic of corrosivity (40 CFR 261.22), EPA's data show

that mixtures of CKD and water often exhibit the characteristic of

corrosivity. 11 In particular, EPA data show that the pH

level in run-off from precipitation that contacts CKD storage and waste

piles typically exceeds 12.5 standard units, the standard for the

corrosivity characteristic for hazardous wastes (40 CFR 261.22). In

addition, EPA's analyses of CKD show that CKD does contain certain

metals listed in Appendix VIII (``Hazardous Constituents'') Part 261 of

RCRA. For many of the toxic metals, the total concentrations in kiln

dust were not significantly different whether the dust was generated in

kilns that burn or do not burn hazardous waste. Likewise, in terms of

potential constituent solubility and release, leach test results show

that no significant distinction can be made between CKD generated from

kilns that burn hazardous waste and those that do not burn hazardous

waste.

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\11\ EPA hazardous waste identification rules do not include a

characteristic or definition for solid corrosives.

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With respect to organics, volatile and semi-volatile compounds were

generally not found in CKD. However, levels of 2,3,7,8-substituted

dioxin, and 2,3,7,8-substituted dibenzofuran were detected, although

the concentrations were generally low. The calculated 2,3,7,8-

tetrachlorinated dibenzo-p-dioxins toxicity equivalence (TEQ) values

for the facilities sampled by EPA ranged from non-detected to 9 ppt.

d. Adequacy of Existing Regulations

In making its regulatory determination, EPA evaluated State and

Federal regulations pertaining to CKD waste and concluded that more

stringent regulation of CKD is necessary based on current regulatory

schemes. 12

[[Page 45637]]

The Agency also determined that current practices are inadequate to

limit contaminant releases and associated risks. CKD is now managed

primarily on-site in non-engineered landfills, piles, and ponds. Many

piles and landfills lack liners, leachate controls, or run-on/run-off

collection systems. In addition, while dust suppression measures exist

at many facilities, it appears that they are generally ineffective at

controlling airborne releases of CKD. The Agency believes the following

factors warrant additional environmental controls for CKD: (1) the

general lack of current regulations applicable to contaminant

discharges to ground water for protection of human health and the

environment; (2) the general lack of ground-water monitoring systems at

CKD disposal units; and (3) the existence of damages to ground water

and air that are persistent and continuous, and for which no

requirements exist to address the risks posed via these pathways.

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\12\ Supporting documentation for this analysis can be found in

Chapter 7 of the RTC--Existing Regulatory Controls on CKD

Management.

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4. New Analyses

a. Population Risk

Subsequent to the Regulatory Determination, the Agency calculated

population risks for individuals living in the vicinity of cement

manufacturing plants that manage CKD onsite. The assessment included

population risks from indirect, or foodchain, exposure pathways and

population effects from exposure to airborne particles, but not

potential population risks from beneficial use of CKD. This work builds

on earlier CKD analyses focusing on the health risks to maximally

exposed individuals, presented in the RTC on CKD and supporting

documentation, the 1994 NODA on CKD, and a background document

supporting the 1995 CKD Regulatory Determination. A detailed

description of the population risk assessment is provided in the

Technical Background Document: Population Risks from Indirect Exposure

Pathways, and Population Effects from Exposure to Airborne Particles

from Cement Kiln Dust Waste in the docket for this rule.

The assessment of population risks from indirect exposure estimates

the number of cancer cases and the number of people living near cement

plants that are potentially exposed above noncancer effect thresholds

through the ingestion of vegetables, beef and milk, and fish. For this

analysis, existing facility-specific individual risk estimates were

combined with facility-specific data on populations potentially exposed

via indirect pathways to derive facility-specific population risk

estimates. As a first step, information on individual risk generated

from a sample of 82 facilities was used to identify and eliminate from

concern those facilities that have negligible potential for significant

population risk. For remaining facilities, population risk for the

vegetable ingestion pathway was calculated by combining prior estimates

of individual risk with estimates of nearby farmers and backyard

gardeners based on census data. For the final step, results from the 82

facilities for which facility-specific information was available were

extrapolated to the total universe of 108 cement facilities. Population

risk for the fish ingestion pathway was estimated using existing

facility-specific individual risk estimates along with numbers of

recreational fishers that could be exposed, calculated based on fish

yield data from local streams. Facility-specific results were then

extrapolated to the full universe of cement plants to obtain total

population risk for this pathway.

The Agency estimates that exposures via indirect pathways occurring

in populations within five miles of all cement plants nationwide

potentially result in a total of 0.04 excess cancer cases over a 70-

year period. That is, exposures would potentially lead to about 0.009

excess cancer cases in the subsistence farmer population, and about

0.03 excess cancer cases in the ``homegrown'' population. Cancer cases

predicted for the recreational fisher population are negligible. The

total population within five miles of all cement facilities nationwide

is approximately 3.4 million.13 Thus, the overall population

cancer risk can be characterized as follows: a total of 0.0006 excess

cancer cases per year could potentially occur within this population of

3.4 million due to indirect exposures.

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\13\ This is an estimate based on site-specific data for 61

facilities and extrapolated data for the remaining 47 facilities.

---------------------------------------------------------------------------

For population noncancer effects, EPA predicts that, across all

populations within five miles of all cement facilities nationwide, a

total of about 1,040 people are potentially exposed via indirect

exposure pathways to contaminant levels above the hazard index. That

is, about 6 individuals from the population exposed to contamination

from homegrown vegetables are exposed to contamination exceeding

noncancer effects thresholds (i.e., hazard index greater than 1). About

37 individuals from the subsistence farmer population and about 1,000

individuals from the recreational fisher population are estimated to be

exposed to contamination exceeding noncancer effects thresholds. The

overall population noncancer effects can be characterized as follows: a

total of about 1,040 people, or less than one-tenth of one percent,

from among the population of 3.4 million within five miles of all

cement plants nationwide is likely to be exposed via indirect exposure

pathways to contamination exceeding noncancer effects thresholds.

The assessment of population effects from exposure to airborne

particles estimates the number of people potentially exposed to

fugitive CKD at levels above the National Ambient Air Quality Standards

(NAAQS) for particulate matter (PM). Both the existing NAAQS for coarse

particles and a new NAAQS proposed for fine particles were considered.

New modeling of CKD emissions and downwind dispersion was performed for

selected ``high risk'' cement plants, substantially improving on the

previous work by using advanced modeling techniques, estimating

emissions from all CKD handling stages rather than just final disposal

as modeled previously, and considering the effect of terrain, among

other refinements. The concentrations of airborne particles were then

overlaid on census block grids to estimate populations potentially

exposed above the PM10 NAAQS. The Agency estimates that

about 18 people may be exposed to airborne PM10

concentrations in excess of the NAAQS around the 82 facilities for

which facility-specific information is available.14 As with

the indirect exposures analysis, EPA derived a more complete picture of

potential population effects due to PM exposures by extrapolating from

results within the known universe to determine the potential population

effects for the full universe of cement facilities. In sum, EPA

estimated that, across all 108 facilities, a total of between 18 and

4,118 people living within 500 meters of the facility boundary may be

exposed to airborne PM concentrations in excess of the NAAQS. It is not

known what percentage of the population exposed above the NAAQS is

likely to develop any morbid effects because the dose-response

relationship for PM exposures is not well defined.

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\14\ The estimate of 393 people is based on an evaluation of 52

of the 82 cement facilities; based on analyses conducted previously

the remaining 30 facilities were determined to have zero or

negligible effects in terms of PM exposures because they do not

manage CKD on-site (see methodology and results presented in

Technical Background Document on Potential Risks of Cement Kiln Dust

in Support of the Cement Kiln Dust Regulatory Determination, January

31, 1995).

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[[Page 45638]]

b. Additional Ground-Water Modeling

Because the available damage cases indicate the potential for

impacts to ground water in areas of non-karst terrain (four of the 13

damage cases are located in areas of non-karst terrain), the Agency

conducted additional ground-water modeling to evaluate the potential

subsurface transport of metals in non-karst terrain. The additional

modeling occurred in two phases. In Phase I, the Agency tested the

sensitivity of the modeling by incorporating the same assumptions used

in the modeling to support the Report to Congress in EPACMTP, a ground-

water model used by EPA to conduct national assessments. The intent of

this exercise was to determine whether model selection significantly

influenced the conclusions regarding the subsurface transport of

constituents to receptor locations. In Phase II, the Agency evaluated

the sensitivity of EPACMTP to assumptions regarding the speciation and

adsorption of metals. In this analysis, the Agency revised the

isotherms generated by MINTEQA2, a geochemical speciation

model,15 to reflect higher pHs (as found in CKD leachate),

more appropriate ions in the leachate, and a lower dissolved organic

carbon concentration in the leachate.

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\15\ U.S. EPA, 1996a. Background Document for Metals. EPA

Composite Model for Leachate Migration with Transformation Products

(EPACMTP). Volume 1: Methodology. U.S. EPA, Office of Solid Waste,

Washington, DC 20460.

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In Phase I of the additional ground-water modeling, EPA evaluated

the sensitivity of its previous model selection by estimating

constituent concentrations at well locations with EPA's regional

ground-water model, EPACMTP. The results from this analysis were then

compared with the results generated by the previous modeling, which

used MMSOILS. EPACMTP combines a finite source methodology with a

metal-specific procedure (using MINTEQA2) for handling geochemical

interactions that affect the subsurface fate and transport of metals. A

complete description of this methodology is available in EPA Composite

Model for Leachate Migration with Transformation Products: Background

Document for Metals, which has been placed in the RCRA docket in

support of this proposed rule.16 The analysis incorporated

the same data and assumptions used to support the ground-water modeling

for the EPA's 1993 Report to Congress.

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\16\ U.S. EPA, 1996b. EPA Composit Model for Leachate Migration

with Transformation Products (EPACMTP) Background Document. U.S.

EPA, Office of Solid Waste, Washington, DC 20460.

---------------------------------------------------------------------------

In general, the revised modeling using EPACMTP predicted lower

concentrations of metals in ground water for antimony, arsenic,

chromium, cadmium, and thallium and higher concentrations for barium

and beryllium. At all facilities, the risk from contaminated ground

water predicted by EPACMTP was negligible. Leaching of lead was

negligible in both modeling exercises (the MMSOILS model predicted that

lead would reach the water table at only one modeled facility). From

this analysis, the Agency concluded that the selection of ground-water

models was not the most significant reason for the inability of the

modeling to predict elevated metal concentrations in ground water.

In Phase II of the additional ground-water modeling, EPA evaluated

the sensitivity of the ground-water modeling results to changes in

assumptions regarding the speciation and adsorption of metals in CKD

leachate. Specifically, EPA revised the assumptions about pH, presence

of leachate organic acids, and ions present in CKD leachate to generate

new partitioning coefficients (Kds) for five metals: barium,

beryllium, cadmium, chromium, and lead. The Agency then used the same

modeling protocol for EPACMTP described above to evaluate the effects

on ground-water fate and transport of these five metals. A more

detailed description of the revisions to the MINTEQA2 isotherms and the

caveats associated with these analyses are available in the technical

support document Examination of Metals Transport under Highly Alkaline

Conditions, which has been submitted to the docket in support of this

proposed rule.

This additional analysis indicates that migration of the metals may

be sensitive to the pH of the leachate and the buffering capacity of

the unsaturated and saturated zones. Under highly alkaline conditions

with little or no buffering, cadmium, chromium, lead, barium, and

beryllium are predicted to be more mobile. In general, these metals

displayed a greater tendency to move through the unsaturated zone and

reach the ground water. For example, the analysis indicated that at

four of the five modeled facilities, elevated levels of barium,

beryllium, cadmium, chromium, and lead were found in the ground water

within 10 meters of the disposal unit. At four of the modeled

facilities, concentrations of lead exceeded EPA's action level for lead

of 0.015 mg/L within 10 meters and at one facility, chromium exceeded

its maximum concentration limit (MCL) of 0.1 mg/L by less than a factor

of 10. In addition, modeling indicated that beryllium, cadmium, and

chromium would have concentrations within a factor of 10 of their

respective MCLs at four facilities, one facility, and two facilities,

respectively.

c. New CKD Waste Characteristics Data

In an effort to further understand the influence of hazardous waste

burning on CKD composition, EPA has undertaken analyses of two new

sources of data on toxic metals in CKD. In June 1996, as part of a RCRA

Sec. 3007 data request, EPA collected information on constituent

concentrations in CKD from seven cement plants within Region VII that

burn hazardous waste, to the extent available for each of the five

years 1991 through 1995. In October 1996, new CKD constituent data from

15 cement plants that do not burn hazardous waste, collected during

July and August 1996, were submitted to the Agency by the Non-Hazwaste

Burner CKD Coalition (NHBCC).

The EPA Region VII data set consists of analytical results from a

substantial number of CKD samples, varying by plant, by constituent,

and by year from a few dozen to a few hundred per year. All of these

data reflect CKD generated by the seven plants while burning hazardous

waste. The NHBCC data set consists of analytical results from six to 32

CKD samples from each non-burning plant. Although both data sets have

their individual nuances, the Agency believes these data sets together

accurately reflect constituent values in CKD for both types of kilns,

and tend to complement one another. Both data sets are available in the

RCRA docket for this rule.

The NHBCC, Environmental Technology Council (ETC), and local

citizen groups have asserted to EPA staff that these new data

demonstrate statistically significant differences in the concentrations

of total metals between CKD from kilns that burn conventional fossil

fuels (``non-hazardous waste burner CKD'') and CKD from kilns that burn

RCRA hazardous waste (``hazardous waste burner CKD''). The NHBCC argues

that these differences affect the potential risk associated with the

disposal of CKD and that non-hazardous waste burner CKD exhibits only

isolated elevated concentrations of toxic constituents, hence

relatively low risk compared to hazardous waste burner CKD. As

explained in Section III.C. below, the NHBCC believes these differences

justify EPA imposing a regulatory distinction between hazardous waste

burner CKD and non-

[[Page 45639]]

hazardous waste burner CKD, a so-called ``two-dust approach.''

EPA has considered the NHBCC's assertion of statistical differences

between hazardous waste burner and non-hazardous waste burner CKD, but

at this point based on available data does not accept their assertion

of lower risk for non-hazardous waste burner CKD relative to hazardous

waste burner CKD for the following reasons. First, when hazardous waste

burner and non-hazardous waste burner CKD data sets are compared, for

some toxic metals the statistical distribution of concentrations in

each group significantly overlap. For example, for the constituent

arsenic, CKD from ten out of 15 non-hazardous waste burner plants have

mean total concentrations in excess of the mean concentration of

arsenic in hazardous waste burner CKD averaged from the seven hazardous

waste burning plants in EPA Region VII (1995 data); and CKD from seven

out of 15 non-hazardous waste burner plants have mean arsenic

concentrations higher than the mean concentration reported for

hazardous waste burner plants in the EPA NODA. Similarly, for chromium,

CKD from four out of 15 non-hazardous waste burner plants have mean

total concentrations in excess of the mean concentration for chromium

in hazardous waste burner CKD averaged from the seven hazardous waste

burning plants in EPA Region VII (1995 data). Because of this overlap,

EPA does not believe that all non-hazardous waste burner CKD poses less

potential hazard than hazardous waste burner CKD. Furthermore, a

comparison of means suggests constituent concentrations for all toxic

metals are within the range of data reported in the EPA NODA. EPA

believes that the new information supports the Agency's previous

conclusion that metals levels in CKD are not substantially different,

whether generated by kilns that burn hazardous waste or kilns that do

not burn hazardous waste.

Second, concentrations of the toxic constituent thallium in non-

hazardous waste burner CKD are consistently higher than in hazardous

waste burner CKD. The mean concentration for thallium in non-hazardous

waste burner CKD from the 15 NHBCC plants (180.5 mg/kg) 17

is over three times higher than the mean concentration for 31 non-

burning plants reported in the EPA NODA (52.3 mg/kg), and 47 times

higher than the mean concentration in hazardous waste burner CKD from

the seven EPA Region VII plants (3.8 mg/kg). The NHBCC has argued that

relatively higher concentrations of thallium in non-hazardous waste

burner CKD are not caused by fuels but by CKD recirculation and,

therefore, non-hazardous waste burner CKD should not be regulated

because this material is never disposed. The Agency believes

recirculation of CKD back into the cement manufacturing process is

beneficial because recirculated CKD would never be disposed. Forty-

seven out of 88 non-hazardous waste burner plants, however, reported

wasting CKD in 1995, so the Agency remains concerned that disposal of

CKD with elevated levels of thallium could still pose a potential

hazard to human health and the environment.

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\17\ The highest thallium values in CKD reported from the 15

NHBCC plants are associated with cement kilns that recycle over 90%

of their CKD back into the manufacturing process.

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Third, the NHBCC data have not addressed the cases of environmental

damage or PM10 risks that form the basis of the EPA's

Regulatory Determination. The Agency finds no basis for changing the

Regulatory Determination to regulate only CKD from hazardous waste

burning kilns. The damage cases resulted from on-site management of CKD

in non-engineered landfills, piles and ponds, at plants that largely do

not or did not burn RCRA hazardous wastes. In addition, CKD, regardless

of fuels burned, contains particles 10 microns in size and smaller, and

could potentially pose risks to human health if released through

fugitive emissions.

EPA requests additional data on hazardous waste burner and non-

hazardous waste burner CKD. If new information warrants such action,

the Agency would re-evaluate its current position on the appropriate

levels of control for hazardous waste burner and non-hazardous waste

burner CKD.

D. Beneficial Use of Cement Kiln Dust

It is likely that even with advances in recycling technologies,

some CKD will need to be removed from kiln systems. Because resources

are lost when CKD is permanently disposed, and because disposal

practices can be burdensome, finding alternative uses for waste CKD can

help facilities avoid disposal costs and generate additional revenue,

while at the same time reduce the amount disposed of in landfills.

Currently, CKD is used beneficially for sludge-, waste-, and soil-

stabilization, land reclamation, waste remediation, acid

neutralization, agricultural applications, such as a fertilizer or lime

substitute, and construction applications. 18 According to

responses from the 1991 Portland Cement Association (PCA) Survey and

RCRA section 3007 requests, about 780,000 metric tons (860,000 tons) of

CKD were used beneficially in 1990, or 5.4 percent of the gross CKD

generated in 1990, and about 19 percent of the net CKD generated for

that year. This total represents 9.5 percent of the 8.2 million metric

tons of CKD recycled directly back into the kiln or raw feed system in

1990. Of the 780,000 metric tons, about 71 percent (670,000 metric

tons) was used for waste stabilization, 12 percent (111,000 metric

tons) for soil amendment, 5.6 percent (53,000 metric tons) as liming

agent, nearly three percent (25,000 metric tons) as materials

additives, about one percent (11,000 metric tons) as road base, and

eight percent (76,000 metric tons) for other uses.

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\18\ Bhatty, J.I., 1995, Alternative uses of Cement Kiln Dust.

Portland Cement Association Publication RP327, 18p.

---------------------------------------------------------------------------

The American Society for Testing and Materials (ASTM) standards

advise that use of CKD should be undertaken only after the material's

characteristics have been properly evaluated with respect to the

intended application. ASTM also recommends frequent performance testing

until the degree of variability has been established. 19 The

manner and extent of CKD adaptation for beneficial applications is in

constant flux as research and development of CKD use continue to grow.

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\19\ ASTM, 1991. Standard Guide for Commercial Use of Lime Kiln

Dusts and Portland CKDs. 1990 Annual Book of American Society for

Testing and Materials Standards. Volume 11.04. Method Number D5050-

90. pp. 172-174.

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Most current off-site uses, such as for waste stabilization or land

application as fill material, are either currently regulated (under

RCRA for hazardous waste stabilization, or under the Clean Water Act in

the case of municipal sewage sludge) or appear to present low risk due

to low exposure potential. As explained in the Regulatory

Determination, in light of the low exposure potential, EPA believes

that these uses constitute environmentally sound recycling and

beneficial use. Therefore, the Agency is not proposing management

standards for these beneficial uses of CKD or to list as a hazardous

waste CKD used for such practices. We are proposing that beneficially

used CKD is non-hazardous waste. Thus, with the exception of CKD used

for agricultural purposes, EPA solicits comments on these and other

potential uses that might constitute environmentally sound recycling or

beneficial use.

As explained previously, the Agency's risk assessment data on the

use of CKD as a lime substitute on agricultural fields indicates that

some small percentage of CKD (roughly 5%) may

[[Page 45640]]

present risk to human health and the environment and, therefore, the

agricultural use of CKD warrants controls. Accordingly, in today's

rule, EPA proposes to limit concentrations for arsenic, cadmium, lead,

thallium and chlorinated dibenzodioxins and dibenzofurans in CKD used

for agricultural purposes. If used for agricultural purposes, CKD with

concentrations of these substances in excess of today's proposed

limiting concentrations would be considered a listed hazardous waste.

III. Discussion of Options To Address Risks From Mismanaged CKD

Today's proposal presents several possible approaches, including

the Agency's preferred approach for addressing the hazards presented by

CKD. EPA invites commenters to address these approaches, so that EPA

can evaluate the Agency's preferred approach not only on its own merits

but also in comparison to these alternatives. If, when issuing the

final regulation for CKD, EPA were to rely on a Memorandum of

Understanding, regulation exclusively under Subtitle D of RCRA, the

State-based approach, and the Two-Dust approach presented below, the

Agency would have to revisit the Regulatory Determination.

The Agency would more favorably consider the State-based regulatory

approach or MOU if: (1) there were more evidence that cement

manufacturing facilities have made improvements to their CKD management

practices; (2) there was greater agreement among all stakeholders

regarding appropriate CKD management standards; (3) there was a strong

level of support from industry, States, and other stakeholders for

movement toward an MOU or State-based approach; and (4) the alternative

adequately considered the interests of other parties with a stake in

the Agency's CKD rulemaking. In making a final rule determination, EPA

may consider some combination of the alternative approaches discussed.

A. State-Based Approach

The American Portland Cement Alliance (APCA) has submitted a

proposal to EPA for a State-based approach to cement kiln dust (CKD)

management. The main components of APCA's proposed approach are listed

below, in chronological order:

(a) EPA Would Complete Work on CKD Management Standards. EPA would

complete internal work, already begun during discussions regarding

APCA's proposed enforceable agreement, which is discussed above in

Section III.A.--State-Based Approach, to refine the CKD management

standards for issuance as guidance as provided below.

(b) EPA Would Publish Proposed Guidance and ``Backstop'' Regulatory

Regime For Public Comment. APCA proposes that EPA would publish a

Notice of Data Availability in the Federal Register which would have

two separate components. The first component would describe and

summarize the key components of the CKD management standards, and

announce the public availability of a complete copy of the CKD

management standards. APCA proposes that in the Notice, the Agency

would announce its willingness to withdraw its earlier Regulatory

Determination if all of the States in which CKD is land disposed

developed an adequate CKD management program within two years. The

second component would be a ``backstop'' proposed rule based on a

``conditional exclusion'' or ``contingent management'' approach in

which RCRA Subtitle C authority would not be triggered unless the

conditions of the exclusion were violated. APCA proposes that EPA would

finalize the proposal only if one or more States in which CKD is land

disposed do not have an adequate CKD management program within two

years. EPA would solicit public comment on all aspects of the Notice.

(c) EPA Would Publish Final Guidance In Response To Public Comment.

APCA proposes that one year after publishing the initial guidance and

backstop proposal, EPA would publish its ``final'' guidance in a

subsequent Federal Register notice in response to public comments. In

this notice, EPA would also include an explicit time line for the

remaining steps in the State-based approach.

(d) EPA Would Take Final Action Regarding Inadequate State

Programs. Two years after publishing the initial proposed guidance and

backstop proposal, APCA proposes that EPA would publish another Federal

Register notice announcing its assessment of the adequacy of State CKD

management programs. APCA proposes that if EPA finds that such State

programs are adequate, the Agency would announce withdrawal of its 1995

Regulatory Determination. Conversely, if the Agency finds one or more

States with inadequate CKD programs, APCA proposes that EPA issue a

final rule that will be effective in those States. These regulations

would be based on a conditional exemption approach in which RCRA

Subtitle C authorities would not be invoked unless terms of the

exemption were violated. For those States with adequate programs, EPA

would withdraw its 1995 Regulatory Determination.

The technical standards in today's proposed rule reflect completed

internal work on appropriate CKD management standards and could serve

as the Notice that APCA suggests in (b) above. In our view, the Part

259 standards represent proposed final management standards for CKD

management, and the standards proposed today under Part 261 could form

a ``backstop rule.'' The Agency solicits comments on APCA's proposed

State-based regulatory approach for CKD management and on the details

of State programs affecting the management and beneficial use of CKD.

Both APCA's proposed CKD management standards that were submitted to

the Agency as part of the proposed enforceable agreement, and a full

description of APCA's State-based approach are available in the RIC in

support of this rule.20

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\20\ The cement industry's proposed management practices

(version 6/1/5), see RIC docket No. F-99-CKDP-S0031.

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B. Memorandum of Understanding

Another option considered by the Agency, in lieu of a detailed

regulatory scheme, would be to enter into a memorandum of understanding

(MOU) with the cement industry. As with enforceable agreements, a MOU

would include specific standards for the management of CKD. This

approach is not unprecedented.

In January 1994, EPA and the American Forest and Paper Association

(AF&PA) negotiated a MOU regarding the implementation of land

application agreements among AF&PA member pulp and paper mills and the

EPA.21 The purpose of the MOU was to develop a stewardship

program for the practice of land application of pulp and paper mill

sludges. Each paper mill participating in the program signed a ``Land

Application Agreement'' which established standards and land management

practices for the mill's land application of sludge. The MOU also

provided for annual materials monitoring reports to be submitted to

EPA, AF&PA member outreach programs, and annual AF&PA member surveys.

The individual ``Land Application Agreements'' specify, among other

things, dioxin/furan concentration limits for land applied sludge and

receiving soils, application rates, waste testing requirements, and

recordkeeping and reporting requirements. MOU and ``Land Application

Agreements'' do not

[[Page 45641]]

provide for enforcement, including citizen suits. Moreover, EPA, to

date, has not formally assessed the success of the Agreements.

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\21\ For a copy of the MOU, see RIC docket No. F-99-CKDP-S0107.

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The Agency could consider a similar approach to tailored management

standards and for monitoring the management of CKD. The Agency solicits

comments on the advantages and disadvantages of a program utilizing

either an enforceable agreement, which is discussed above in Section

III.A.--State-Based Approach, or memorandum of understanding to

encourage environmentally-sound CKD management practices.

C. Two-Dust Approach

In meetings with EPA staff, the Non-Hazwaste Burner CKD Coalition

(NHBCC) has argued that any proposed regulatory mechanism for CKD,

should distinguish between CKD from kilns that burn conventional fossil

fuels (non-hazardous waste burner CKD) and CKD from kilns that burn

RCRA hazardous waste, both in oversight mechanisms and in the contents

of any minimum management practices. The NHBCC has argued that EPA

should reimpose the Bevill exclusion for non-hazardous waste burner

CKD, supplemented where necessary and justified by an appropriate

voluntary program or discretionary steps by the States. According to

the NHBCC, EPA should regulate hazardous waste burner CKD in the least

burdensome manner consistent with any relevant risks that the dust may

present.

The NHBCC has cited several points in support of a two-dust

approach. First, the NHBCC has argued that less stringent treatment for

non-hazardous waste burner CKD is justified on the basis of new CKD

waste characteristics data which shows low risk (see Section

II.C.4.c.--New Waste Characteristics Data, above). Second, the NHBCC

states that unit costs of managing stockpiled CKD would increase to

prohibitive levels for some member companies which are small businesses

as defined by the Small Business Administration. According to the

NHBCC, these small businesses do not have any additional revenue

streams, unlike cement facilities that burn RCRA hazardous wastes, to

offset the additional costs of CKD management. Third, the NHBCC has

expressed concern that Federal regulation of CKD under RCRA Subtitle C

will discourage beneficial re-use by stigmatizing CKD as a hazardous

waste. The NHBCC claims that such regulation would undermine public

confidence in CKD as a material suitable for reuse, discourage the

development of new markets for CKD waste, and force up compliance costs

by compelling facilities which currently sell CKD to stockpile it

instead. EPA solicits comment on the NHBCC's proposed two-dust approach

and requests additional data on hazardous waste burner and non-

hazardous waste burner CKD. If new information warrants such action,

the Agency would re-evaluate its current position on the appropriate

levels of control for hazardous waste burner and non-hazardous waste

burner CKD.

D. Develop Regulations Under Authority of Subtitle D

Another option would be to issue standards such as those described

in today's Notice solely as RCRA Subtitle D requirements, relying on

authority in RCRA section 4004(a). Under this approach the standards

would be enforceable by the public through citizen suits. EPA would

additionally encourage States to adopt standards developed under

Subtitle D as enforceable standards under State law, but the Agency

could not compel them to do so. Such standards would not be directly

enforceable by EPA under the enforcement authorities of sections 3007

and 3008. EPA could take enforcement action under section 7003, if

there is a finding of substantial endangerment. In contrast, the Agency

is today proposing a regulatory structure that would provide the

opportunity for Federal enforcement against major violations of the

proposed standards, where warranted (see Sec. 261.4(b)(8)(ii)(A)). The

Agency solicits comment on issuing today's proposed standards solely as

RCRA Subtitle D requirements and views on the need for Federal

enforcement of major violations of the proposed standards.

E. Subtitle C Enforcement Without Listing CKD

APCA has suggested that EPA could adequately regulate CKD not

managed in accordance with today's proposed Part 259 standards using

RCRA enforcement authorities without having to identify the mismanaged

CKD as a RCRA hazardous waste. APCA asserts that as long as EPA

specified that a violation of the Subtitle C backup standards in Part

266 constitutes a ``violation of the requirements of RCRA Subtitle C,''

then EPA and citizens could enforce against those violations under RCRA

sections 3008(a) and 7002(a) respectively. Similarly, APCA asserts that

EPA could enforce against violations under RCRA section 3008(d)(3)

criminal enforcement authority. APCA's approach is more specifically

set forth in a letter to EPA dated August 24, 1998, and is available in

the RIC docket for this rule. EPA invites comment on APCA's approach.

F. Tailored Standards Under Subtitle C

Another option available to the Agency is to regulate all CKD under

authority of Subtitle C, using the tailored standards proposed today

(i.e., the standards that would apply to CKD which, under today's

proposal, would become hazardous waste because it is being improperly

managed). Under this approach, all CKD would be listed hazardous waste

and would be regulated under the tailored standards proposed today in

Part 266 which incorporates the standards proposed today in Part 259.

The Agency solicits comment on the option of regulating all CKD

under authority of RCRA Subtitle C and whether certain provisions could

be eliminated or whether additional provisions are needed.

G. States Adopt Appropriate Programs

Alternatively, States may come forth with appropriate programs for

managing CKD. Such programs would have requirements similar to those

listed in Sections IV., V., and VI. of today's proposal, and include

standards for addressing risks posed by fugitive CKD, standards for

addressing risks to ground water, standards for agricultural use of

CKD, and requirements for monitoring, reporting, and corrective action.

The Agency believes there may be no need to finalize a Federal program

if States with cement facilities that dispose CKD adopt appropriate

programs and standards for managing CKD. The Agency solicits comment on

the option presented in this paragraph of States adopting appropriate

programs.

H. Today's Approach--Exclude Properly Managed CKD From Hazardous Waste

Listing

1. Develop Management Standards and Exempt Properly Managed CKD From

Classification as a Hazardous Waste (Management-based Listing)

Today's proposed rule would regulate CKD under RCRA to address the

concerns identified in the RTC while avoiding unnecessary requirements.

The approach taken is to establish management standards for CKD and

make it clear that all CKD managed in accordance with those standards

is not classified as a hazardous waste. CKD not managed in accordance

with the standards, on the other hand, is proposed to be listed as a

hazardous waste under 40 CFR 261.11.

The concept of regulating a waste if it fails to meet certain

standards forms the

[[Page 45642]]

basis of many RCRA regulations. To provide added flexibility for

implementation, EPA has previously proposed options for conditional

exemptions from Subtitle C regulation for certain refining

wastes,22 and promulgated conditional exemptions for non-

chemical military munitions.23 Today's proposed rule would

limit regulation of CKD under Subtitle C to that CKD which is

mismanaged.

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\22\ See 60 FR 57747, November 20, 1995, Hazardous Waste

Management System; Identification and Listing of Hazardous Waste;

Petroleum Refining process Wastes; Land Disposal Restrictions for

Newly Identified Wastes; and CERCLA Hazardous Substance Desigination

and Reportable Quantities.

\23\ See 62 FR 6621, February 12, 1997, Military Munitions Rule;

Hazardous Waste Identification and Management; Explosives

Emergencies; Manifest Exemption for Transport of Hazardous Waste on

Right-of-Ways and Contiguous Properties; Final Rule.

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The DC Circuit Court of Appeals has expressly upheld EPA's

authority under RCRA to establish a conditional exemption from Subtitle

C regulation for wastes that, absent the exemption, would be hazardous

(see Military Toxics Project v. EPA, 146 F. 3rd. 948, D.C. Cir. 1998).

For a more detailed discussion of EPA's authority to establish a

conditional exemption from Subtitle C regulation, see the discussion at

62 FR 6636-6637 of the Military Munitions Rule preamble.

Accordingly, EPA is today proposing to: (1) establish standards

that define proper management of CKD waste; (2) exempt from

classification as hazardous waste all CKD managed in accordance with

specific standards proposed today; (3) list mismanaged CKD as a

hazardous waste based on the criteria defined at 40 CFR 261.11(a)(3)(i-

xi); and (4) provide tailored standards under Subtitle C for the proper

management of CKD that has been mismanaged. The Agency's evaluation of

mismanaged CKD against the listing criteria in Sec. 261.11(a)(3) can be

found in Appendix I of this preamble, while the associated evaluation

of reportable quantities for releases of CKD can be found in Appendix

II of this preamble. Under the proposed approach, CKD would only become

hazardous waste subject to RCRA Subtitle C regulation when persons

managing the waste commit egregious or repeated violations, such as

failing to install controls designed to meet the performance standards,

or failing to manage CKD in units that conform to specific default

technology-based standards. CKD managed in accordance with today's

proposed standards would be outside the scope of Subtitle C, and would

not be considered hazardous waste. The Agency believes the CKD

management standards proposed today will protect the public from human

health risks and prevent environmental damage resulting from current

CKD disposal practices. The standards are designed to prevent

contamination of ground water and potable water supplies, and prevent

human health risks from inhalation of airborne CKD and ingestion via

food chain pathways.

In developing the proposed management standards for cement kiln

dust, EPA considered several factors. First, and primarily, the Agency

believes that subjecting waste CKD to the full RCRA Subtitle C program,

while protective, would be prohibitively burdensome on the cement

industry, and is not a feasible regulatory option under the factors

cited in RCRA section 8002(o). The full Subtitle C regulatory program

would be highly prescriptive and provides little tailoring for site

specific conditions. Second, the CKD management standards proposed

today are based on EPA's current knowledge of the cement industry and

the human health and environmental risks posed by CKD. The Agency

considers these technical standards to be sufficient to control the

specific risks identified while eliminating unnecessary compliance

costs. EPA believes that for CKD, imposing the additional requirements

of full Subtitle C would add significantly to compliance costs without

a reduction in risks (see the Regulatory Determination for CKD:

Potential Costs and Impacts of Subtitle C Regulation, 60 FR 7371,

February 7, 1995).24 Third, the Agency desires to encourage

the common industry practice of recycling of CKD waste back into the

industrial process, and promote environmentally sound off-site

beneficial use of this material. Most current off-site uses, such as

for waste stabilization or general construction, are either currently

regulated (under RCRA for hazardous waste stabilization, or under the

Clean Water Act in the case of municipal sewage sludge) or appear to

present low risk due to low exposure potential. Classifying all CKD as

hazardous could prevent such uses because of the expense resulting from

hazardous waste management requirements.

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\24\ Supporting documentation for these cost analyses can be

found in the Technical Background Document: Data and Analyses

Addressing the Costs of CKD Management Alternatives, RIC Docket Nos.

F-94-RC2A-S0018 and S0018.A),

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EPA emphasizes, however, that if persons mismanage CKD waste,

depending on the nature in which it is mismanaged, the non-compliant

waste may become subject to Subtitle C requirements which would include

enforcement action for violations of the proposed management standards

(see Section V. B.--Implementation of Part 259 and RCRA Subtitle C

Backup Standards). The Subtitle C requirements applicable to such CKD

would to some extent be tailored as appropriate to ensure proper

management of CKD. For example, the proposed Subtitle C design

requirements for CKD landfills are different from those under the

generally-applicable Subtitle C regulations. However, other generally-

applicable RCRA requirements would apply to persons managing listed CKD

as hazardous waste. In particular, persons managing listed CKD would be

required to obtain permits if they treat, store or dispose of hazardous

CKD, and to manifest shipments of hazardous CKD. Certain generally

applicable RCRA requirements would not be applied to hazardous CKD,

under the authority of section 3004(x) of RCRA. These include land

disposal restrictions, minimum technology requirements, and facility-

wide corrective action requirements.

2. Alternative Management-Based Listing

Another approach EPA considered would be to list as a hazardous

waste only CKD that is managed according to specific practices that are

known to pose significant risks to human health and the environment.

For example, the management of CKD in unlined landfills, under water or

in direct contact with the ground-water table, without fugitive dust

controls, or when used for agricultural purposes without proper

controls, is likely to pose significant risks to human health and the

environment. Under this approach, CKD mismanaged in these specified

ways would be listed as hazardous waste. One disadvantage to this

approach is that while it may prevent those poor management practices

identified by the Agency at this time, such a listing would require the

Agency to anticipate and identify all possible ways that CKD could be

mismanaged. The Agency requests comments on the advantages or

disadvantages of this approach over the approach proposed today,

including comment on additional mismanagement practices that should be

identified and considered if such an approach were adopted.

3. Characteristic CKD

CKD rarely exhibits a hazardous characteristic. Under the rule

proposed today, characteristic CKD would, in most cases, be regulated

in the same manner as other CKD. That is, it would be exempt from the

definition of

[[Page 45643]]

``hazardous waste'' so long as it is managed in accordance with the

specified standards; if not so managed, as described above, it would be

subject to tailored Subtitle C requirements. The sole exception to this

approach would be for CKD from kilns that burn hazardous waste as fuel,

which would be subject to full (not tailored) Subtitle C requirements

if it fails the two-part test in the Boiler and Industrial Furnace Rule

(a prime component being a comparison to hazardous characteristic

criteria for metals). This approach maintains in place the rules for

CKD from hazardous waste burners that exist currently under 40 CFR

266.112.

4. Apply Tailored RCRA Subtitle C Standards to Improperly Managed CKD

As described previously, CKD that has been determined to be

improperly managed and no longer a non-hazardous waste would be subject

to Subtitle C standards that are tailored to address the risks

presented by CKD. The management standards applicable to such CKD would

be promulgated under EPA's general authority for setting management

requirements for hazardous waste under sections 2002(a)(1), 3002, 3003,

and 3004 of RCRA.

Subtitle C requirements that apply to hazardous waste generally,

and are not expressly modified in these tailored standards, would apply

to CKD or facilities managing CKD. For example, if a person managing

CKD waste disposes of non-exempt CKD onsite, she or he would be

required to obtain a RCRA permit. However, EPA has authority under

section 3004(x) of RCRA to alter certain statutory requirements that

would otherwise apply to all hazardous waste facilities, for wastes

previously subject to the Bevill exclusion and newly being brought

under Subtitle C regulation. In particular, EPA has authority to modify

requirements relating to land disposal restrictions, minimum technology

for landfill design, and facility-wide corrective action. EPA would

rely on this authority to exempt CKD from land disposal restrictions,

minimum technology requirements, and facility-wide corrective action

requirements as we are proposing today. A more detailed discussion of

the reasons for this approach under section section 3004(x) can be

found in Section V.A.1.-3004(x)--Special Characteristics.

IV. Proposed Management Standards

A key element of the regulatory system for CKD described above is

the standards to be established for CKD management. As discussed above,

as long as CKD is managed according to these standards, it would remain

a non-hazardous waste. Furthermore, compliance with these standards

would be required under the tailored RCRA Subtitle C requirements

applicable to any CKD that is mismanaged.

Because these standards are a condition for maintaining non-

hazardous status, EPA proposes to promulgate them at 40 CFR Part 259,

separate from the regulations governing hazardous waste. The tailored

RCRA Subtitle C regulations for hazardous CKD waste are proposed to be

promulgated in 40 CFR Part 266; those regulations will incorporate the

Part 259 proposed standards by reference, in addition to identifying

the other Subtitle C requirements applicable to hazardous CKD.

A. Protection of Ground-Water Resources

1. The Need for Ground-Water Protection Standards

As tabulated in the background document for today's proposed rule

titled Technical Background Document on Ground Water Controls at CKD

Landfills, EPA has identified 13 cases of ground water damage resulting

from the migration of potentially hazardous constituents, including

metals, from waste CKD.25 These damages reflect CKD

management practices from 1980 to 1995 at cement facilities across the

United States. While the Agency acknowledges that CKD management

practices may have changed at individual cement manufacturing sites,

EPA believes certain practices which have led to damages to ground and

surface waters have not stopped and occur today at other cement

manufacturing facilities nation-wide.

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\25\ Detailed writeups for each of the 13 ground-water damage

cases can be found in Chapter 5 of the RTC, the Technical Background

Document:Additional Documented and Potential Damages from the

Management of Cement Kiln Dust (F-94-RC1A-S0003 to S0015); and the

Technical Background Document. Additional Documented Damages to

Ground Water From the Management of cement Kiln Dust, which has been

placed in the RIC docket in support of this proposed rule.

---------------------------------------------------------------------------

The Agency considers damage to mean that metal constituents have

contaminated ground water and/or surface water above a Federal or State

standard (e.g., a maximum concentration limit). Constituents of concern

from CKD that have been released to ground and surface waters include

arsenic, chromium, and lead, among others. When ground-water

exceedances do occur, the magnitude of the exceedance is usually within

two orders of magnitude of the standard. Environmental damage generally

affects the area in the immediate vicinity of the waste disposal site.

Environmental damage has been identified both at facilities that burn

and those that do not burn RCRA hazardous wastes.

As documented in Table 2-1 of the technical background document on

ground water controls, the Agency finds that many factors have

contributed to causing the release of CKD constituents to ground water

or the subsurface environment at these damage case sites. Factors which

are noted to have contributed to the release of CKD constituents into

the sub-surface environment include: (1) CKD disposal below the natural

water table or ground-water infiltration into the waste unit; (2) the

lack of a bottom liner or leachate collection system, or both, to

control leakage from the waste unit; (3) surface run-off or erosion

transporting CKD constituents to surface water bodies and/or wetlands

which can serve as a source of ground-water recharge; (4) the lack of

an impermeable cover to control percolation of rain water and/or

surface water run-off into the waste unit; and (5) the presence of a

shallow ground-water flow system with conduit flow characteristics

(e.g., karst aquifer or fractured bedrock aquifer). Notably, all of the

damage cases are associated with CKD waste disposal units which did not

have bottom liners, leachate collection systems, or impermeable covers

in place during the active disposal period.

The cement industry, because it uses limestone, has a relatively

high percentage of CKD disposal sites located in potential karst areas

that is unique compared to other industries the EPA regulates. The

Agency estimates that 78 out of 110 plants are underlain by limestone

formations in areas of potential karst terrain. Based on additional

analysis performed in support of today's proposed rule which is

documented in the technical background document on ground water

controls, the Agency has increased the estimate of the percentage of

cement plant sites located in potential karst areas from about half to

71%.

The Agency believes these limestone formations may have conduits

with hydraulic characteristics that potentially allow leachate to

rapidly enter ground-water aquifers directly without substantial

dilution or attenuation. As documented in the technical report

supporting this rule titled Cement Kiln Dust Migration Pathway,

modeling results for one CKD disposal site (Facility A) did not predict

breakthrough of contaminants into the ground-water table within 130

years, even under highly alkaline conditions. Ground-water and surface

water

[[Page 45644]]

releases, however, which are described in the technical background

document for this proposed rule titled Additional Documented Damages to

Ground Water From the Management of Cement Kiln Dust, occurred at the

same site in 1995, within 30 years of first receipt of waste. The

faster ground-water migration time can be attributed to fractures in

the limestone and an upper perched water table. These factors were not

accounted for in the Agency's model, which assumed laminar ground-water

flow in a homogenous granular bedrock. Nor did the Agency's model

account for placement of CKD in direct contact with ground water.

Nine of the 13 cases of groundwater damage identified occurred at

facilities located in karst terrain. The Agency believes the

identification of additional documented damage cases further supports

the qualification, noted in the 1995 Regulatory Determination, that

available ground-water pathway modeling techniques are not applicable

in areas of karst terrain. For example, in two documented damage cases,

excessive discharges of CKD-contaminated waters can be attributed to

ground-water flow through fractured bedrock. In another case, CKD

disposal in caverns has resulted in the discharge of contaminated

ground water into a nearby surface stream. This does not necessarily

mean that ground-water contamination will occur at all such cement

plants; however, it should be regarded as a significant qualification

to the general findings in the RTC of low or negligible risk from the

ground-water pathway risk modeling results. Also, as noted in Section

II.C.4.b--Additional Ground-water Modeling, the conclusions on ground

water modeling should be qualified by the additional analysis conducted

by the Agency. In this analysis, the Agency concluded that the typical

ions in CKD and the highly alkaline nature of the leachate are likely

to mobilize metals, including lead, chromium, and beryllium, at levels

greater than previously predicted. In addition to ground-water

contamination, contamination of surface water and/or wetlands was also

identified as being a concern at twelve of these damage case sites.

At many of these sites, environmental damages are persistent and

continuing. The identification by the Agency of six additional cases of

damage since the 1995 Regulatory Determination indicates that damage to

ground-water resources near CKD disposal sites may be more common than

originally thought in 1995. EPA's latest information indicates that

remedial measures have been initiated at only seven of the ground-water

damage case sites, such as removal of contaminated materials,

installation of an impermeable cap, and/or construction of a seep/

ground-water extraction and treatment system. In two cases, ground-

water contamination has been found that corroborates the surface water

damage cases which were reported in the 1993 RTC and associated NODA.

This suggests that, at these CKD disposal sites, releases of

contaminated water are pervasive. Many of these sites have been slow to

implement remedial measures to control off-site migration of

contaminants.

The Agency further believes ground-water controls are warranted

because of the matrix in which constituents of concern are bound. As

mentioned in Section II.C.4.b. (Additional Ground-water Modeling) of

this proposal, more recent modeling of the highly alkaline conditions

shows that, in general, these conditions increase the likelihood that

some constituents of concern, including lead, chromium, and cadmium,

may be more mobile than previously demonstrated. Specifically, the

Agency has noticed enhanced transport and breakthrough to the water

table for these metals. These new ground-water modeling results support

the findings of increased leachability of toxic metals, as observed in

the damage cases. As reported in the RTC, the highly alkaline nature of

CKD-water mixtures is evident in TCLP results, which commonly show a

resultant pH greater than 10 standard units, even after adding acid.

Current waste management practices appear to be inadequate to limit

releases of at least some metal contaminants. According to a survey by

APCA of 1995 CKD waste management practices, 65% of all respondents

indicated that their landfills had liners, but only one respondent

(1.5%) used a synthetic liner. Over 60% of respondents considered

bedrock or native clay or shale materials to be liners. In 1990, only

17% of all CKD management units nation-wide had ground-water monitoring

systems. The American Portland Cement Alliance reports that in 1995, 33

out of 94 cement manufacturing facilities had ``ground-water monitoring

systems.'' EPA, however, could not verify whether the monitoring

systems were capable of characterizing ground water beneath the active

CKD management unit(s). EPA believes that a substantial portion of the

cement industry relies on inadequate measures to control the release of

contaminants to ground water, and that these practices have not changed

substantially or have only marginally improved over the past several

years.

Finally, as stated in the 1995 Regulatory Determination, the Agency

believes there are no current Federal ground-water protection standards

that are adequate to address the risks posed by CKD via the ground-

water pathway. The Safe Drinking Water Act (42 U.S.C. 300 f-j) protects

drinking water by setting maximum concentration limits (MCLs) for toxic

contaminants, including metals. However, drinking water standards are

only protective at the point of consumption. Public water supply wells,

however, are protected through the wellhead protection program under

the SDWA (41 U.S.C. 300h-7(e)).

2. Applicability

EPA is concerned that today's proposal might create an incentive

for persons managing CKD waste to create unneeded ``units'' or

unnecessarily large units prior to the effective date of the final rule

so that such units would be deemed ``existing units'' and not be

subject to certain requirements of today's proposed rule. To address

this concern, today's proposed definition of ``existing unit''

specifies that expansions would have to be consistent with past

operating practices, or operating practices modified to ensure good

management. The Agency believes this added provision ensures that

persons managing CKD waste will not create new units or unnecessarily

enlarge their existing units to avoid compliance with portions of

today's proposed rule, but at the same time, accounts for legitimate

landfill enlargements or changes in facility operations resulting from

additional waste volumes. EPA solicits comment on whether today's

proposed regulatory distinction between lateral and vertical expansions

would encourage owners and operators to expand existing landfills

laterally prior to the effective date of the final rule to avoid

meeting the requirements applicable to new units. EPA is proposing

ground-water protection standards for all new and existing CKD waste

landfill units, except units closed prior to the effective date of the

rule. Today's proposed performance and technology-based standards would

apply to new units, and any expansion of an existing CKD landfill unit,

defined as any lateral expansion of the waste boundary of an existing

landfill unit. Any lateral expansion would be considered a new unit and

must meet the requirements applicable to new units. In contrast, any

vertical expansion of an existing unit would be considered part of the

existing unit and subject only to those requirements applicable to

existing units. Under this

[[Page 45645]]

proposed definition, any new area of any existing unit that receives

waste after the effective date of this rule is an expansion. All new

and existing CKD landfill units (i.e., the existing landfill plus any

expansion) must comply with ground-water monitoring and corrective

action requirements proposed in today's rule.

With regard to surface impoundments, the Agency has found few

facilities that engage in this CKD management practice. EPA solicits

comment on whether wet handling of CKD in surface impoundments can be

conducted in a manner that meets the performance standards contained in

today's proposed rule. EPA continues to take the position that

placement of CKD in a surface impoundment that is in direct contact

with the ground-water table would not be protective of human health and

the environment.

3. Location Standards

One set of standards for ground-water protection relates to

facility location. EPA has identified locations that require special

restrictions and may influence the location of landfills: sites below

the natural water table, floodplains, wetlands, fault areas, seismic

impact zones and unstable areas, particularly unstable areas in karst

terrain. For other wastes, such as municipal solid wastes, the Agency

has viewed these locations as needing special protection (see 53 FR

33314, August 30, 1988). Accordingly, EPA is proposing to impose

location standards for CKD disposal sites to ensure protectiveness in

the areas described above. With one exception which prohibits CKD

disposal below the natural water table, the Agency is not proposing an

absolute prohibition against siting CKD landfills at these locations;

however, persons managing CKD waste would have to make a showing to the

EPA Regional Administrator (or the State, in authorized States), on a

case-by-case basis that their design is protective in these

environments.

a. Disposal Below the Natural Water Table

Today's proposed rule includes a ban on management of CKD in new

units located below the natural water table. The natural water table is

defined as the natural level at which water stands in a shallow ground-

water well open along its length and penetrating the surficial deposits

just deeply enough to encounter standing water at the bottom. This

level is uninfluenced by ground-water pumping or other engineered

activities.

EPA believes that this stringent restriction is necessary to

protect human health and the environment because of the potential

damage caused by management of CKD at sites located below the natural

water table. The Report to Congress, subsequent Regulatory

Determination, and background documents to this proposed rule all

describe damages to ground water and surface water resulting from

management of CKD at sites (e.g., quarries) that subsequently filled

with water after abandonment. As mentioned above, two of these sites

were once listed on the NPL. In the Regulatory Determination, the

Agency also identified surface water damages resulting from problems

with run-on and run-off, but deferred to its authorities under the

Clean Water Act to control surface water problems.

b. Floodplains

EPA is proposing that new and existing CKD landfill units may not

be located in a 100-year floodplain unless a demonstration is made to

the EPA Regional Administrator (or the State, in authorized States),

that the landfill has been designed so that it does not restrict flow

of the 100-year flood, reduce the temporary water storage capacity of

the floodplain, or result in the washout of solid waste so as to pose a

hazard to human health and the environment. The Agency's rationale

today is consistent with the similar rule regarding municipal solid

waste landfill units (MSWLFs) (see 53 FR 33314, August 30, 1988).

Specifically, floodplains may be adversely impacted by the disposal of

solid waste through potential flooding damages including: (1) Rapid

transport of hazardous constituents by flood water resulting in

degradation of water quality downstream; (2) restriction of flood water

flow, causing greater flooding upstream; and (3) reduction of the

storage capacity of the floodplain, which may cause more rapid movement

of flood water downstream, resulting in higher flood levels and greater

flood damages downstream.

Today's proposal would require that new and existing CKD landfill

units located in a 100-year floodplain be designed and operated to

prevent the adverse effects described above. The intent of today's

proposed rule is to require that CKD landfill units not cause

significant impacts on the flow and water storage capacity of a

floodplain experiencing a 100-year flood. Site-specific information

should be used to evaluate whether a facility has met this standard.

Today's proposal defines the floodplain using the 100-year flood

level.26 This criterion would limit the chance for site

inundation and resulting damages. The intent of this criterion is: (1)

To require an assessment of any new or existing CKD disposal site or

expansion of any existing site in a floodplain to determine the

potential impact of the disposal site on downstream and upstream waters

and land; (2) to prohibit such disposal activities if the site, as

designed, may cause increased flooding during the 100-year flood; and

(3) to require, if the disposal site is located in a floodplain, the

use of available technologies and methods to protect against inundation

by the base flood, and minimize the potential for adverse effects on

water quality and on the flood-flow capacity of the floodplain.

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\26\ To determine whether a CKD landfill unit is in the 100-year

floodplain persons managing CKD waste should use flood insurance

rate maps (FIRMS) developed by the Federal Emergency Management

Agency.

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c. Wetlands

Today's proposal provides that no new CKD landfill unit may be

placed in wetlands,27 unless the person managing CKD waste

makes a specific demonstration to the EPA Regional Administrator (or

the State, in authorized States), that the new unit: (1) will not

result in ``significant degradation'' of the wetland as defined in the

Clean Water Act section 404(b)(1) guidelines, published at 40 CFR Part

230; and (2) will meet other requirements derived from the section

404(b)(1) guidelines. Existing disposal units, including vertical

expansions that are located in wetlands would continue to operate.

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\27\ For purposes of this section, wetlands means those areas

defined by 40 CFR 232.2(r): ``* * * areas that are inundated or

saturated by surface or ground water at a frequency and duration

sufficient to support, and that under normal circumstances do

support, a prevalence of vegetation typically adapted for life in

saturated soil conditions. Wetlands generally include swamps,

marshes, bogs, and similar areas.''

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EPA believes that these restrictions are necessary to protect human

health and the environment because of the special environmental

significance of wetlands and the potential damage caused from siting

CKD landfill units in wetlands. The 1993 Report to Congress and

associated background documents describe the environmental damage that

results by siting CKD landfill units adjacent to wetlands. One case

study describes releases of toxic metals in excess of State standards

for warmwater wildlife habitats, which potentially could damage the

ecological integrity of wetlands adjacent to the CKD disposal site.

Another case study describes

[[Page 45646]]

environmental releases of toxic metals into the nearshore waters of

Lake Huron, which have filled in emergent wetlands and damaged

sensitive aquatic habitats. Today's proposed rule would minimize

wetland degradation by new CKD landfill units and expansions by

allowing siting in wetlands only in cases where protective unit design

has been demonstrated.

Today's proposed rule adopts four major requirements: (1) A

practical alternatives test (Sec. 230.10(a)); (2) the assessment of

compliance with other applicable laws (Sec. 230.10(b)); (3) the

assessment of aquatic degradation (Sec. 230.10(c)); and (4) the

assessment of steps taken to minimize the adverse effects of discharge

(Sec. 230.10(d)). These requirements parallel those in the guidelines

for wetlands protection under section 404(b)(1) of the Clean Water Act.

The guiding principle is that discharges should not be allowed unless

the persons managing CKD waste can demonstrate that such discharges are

unavoidable and will not cause or contribute to significant degradation

of wetlands.

Accordingly, to satisfy the four requirements mentioned above,

before a CKD landfill unit may be sited in a wetland the persons

managing CKD waste must make the following five demonstrations to the

Regional Administrator (or the State in authorized States). First,

alternative sites for the proposed landfill which are located outside

of wetlands must be considered. An alternative site is defined as one

which does not involve wetlands. For a person managing CKD waste to

site a CKD landfill in a wetland, he must clearly rebut the presumption

that a practical alternative is available. Second, a demonstration must

be made that siting in a wetland does not violate any of the provisions

of the following applicable laws: (1) Any applicable State water

quality standard; (2) any applicable toxic effluent standard under

section 307 of the Clean Water Act; (3) the Endangered Species Act of

1973; and (4) the Marine Protection, Research, and Sanctuaries Act of

1972. Third, a demonstration must be made that siting the landfill in a

wetland will not cause or contribute to significant degradation of

wetlands. Fourth, if siting in a wetland is still considered after the

first three demonstrations discussed above, then an additional

demonstration must be made that appropriate and practical steps have

been taken to minimize the potential for adverse effects of the

landfill on wetlands. Finally, it must be shown that sufficient

information is available for making reasonable determinations with

respect to these demonstrations; otherwise, the person managing CKD

waste cannot make the demonstrations necessary to qualify for the

waiver to the ban. In today's proposed rule, EPA has not set a

structure or time frame for approval by the EPA Regional Administrator

(or the State in authorized States), in order to give the regulatory

authority maximum flexibility in setting schedules.

Today's proposed rule addresses only RCRA requirements. Nothing in

today's proposed rule affects any requirements that facilities may have

to comply with under other programs, such as section 404 of the Clean

Water Act which affects disposal in wetlands.

d. Fault Areas

EPA proposes today that no new CKD landfill units may be sited

within 60 meters (200 feet) of a fault that has had displacement in

Holocene time, unless a demonstration is made to the EPA Regional

Administrator (or the State, in authorized States), that an alternative

setback distance of less than 60 meters will prevent damage to the

structural integrity of the CKD landfill unit, and will be protective

of human health and the environment. The Holocene is the most recent

epoch of the Quaternary Period, a period of geologic time that extends

from the end of the Pleistocene Epoch to the present and includes

approximately the last 10,000 years. Regional geologic maps of Holocene

age faults are published by the U.S. Geological Survey. EPA believes

that motion along faults may adversely affect the structural integrity

of CKD landfill units, and that a 60-meter buffer zone is necessary to

protect engineered structures from seismic damages.28

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\28\ A fault is defined as a fracture or a zone of fractures in

any material along which strata on one side has been displeased

relative to strata on the other side. See United States Geological

Survey, 1978, Preliminary Young Fault Maps, Miscellaneous Field

Investigation (MF) 916.

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Earthquakes present a threat to public safety and welfare in a

significant portion of the United States. Damage and loss of life in

earthquakes occur as a result of surface displacement along faults and

ground motion, as well as secondary effects of the shaking such as

ground or soil failure. Faults also present concerns relating to

failure of containment structures for CKD landfills. Today's proposed

standard is designed to protect CKD landfill units from deformation

(i.e., bending and warping of the earth's surface) and displacement

(i.e., the relative movement of any two sides of a fault measured in

any direction) of the earth's surface that occur when a fault moves.

Available information collected in support of the MSWLF rule

suggests that structural damage resulting from earthquakes is most

severe for structures located within 60 meters of the fault trace, and

decreases with increasing distance away from the fault. However, EPA

believes that for some geologic formations the 60 meter setback

distance may be overprotective. Therefore, the Agency has allowed in

today's proposed rule the opportunity for demonstrations to be made to

the EPA Regional Administrator (or the State, in authorized States),

that an alternative setback distance of less than 60 meters will

prevent damage to the structural integrity of the CKD landfill unit.

The Agency requests comment on both the general concept of a location

restriction based on fault areas and the specific 60-meter setback

requirement.

e. Seismic Impact Zones

Today's proposal would require that any new CKD landfill unit

located in a seismic impact zone be designed to resist the maximum

horizontal acceleration in lithified material for the site. The design

features affected include all containment structures (i.e., liners,

leachate collection systems, and surface water control systems).

Seismic impact zones are defined as areas having a ten percent or

greater probability that the maximum expected horizontal acceleration

in lithified material for the site, expressed as a percentage of the

Earth's gravitational pull (g), will exceed 0.10g (i.e., 98.0

centimeters per second per second) in 250 years. The term ``lithified

material'' refers to any consolidated or coherent, relatively hard,

naturally occurring aggregate composed of one or more minerals (e.g.,

granite, shale, marble, sandstone, limestone, etc.). This definition

explicitly excludes loose, incoherent masses such as soils or regolith,

and man-made materials such as fill, concrete or asphalt. EPA's

rationale today is consistent with the similar rule regulating MSWLFs,

and the Agency solicits comment regarding whether it is appropriate to

use the same approach for CKDLFs.

EPA believes that the adverse impact of siting CKD landfill units

in seismic areas justifies the need for a comprehensive standard to

prevent releases from these facilities. Types of failure that may

result from ground motion are: (1) Failure of structures from ground

shaking; (2) failure of containment structures due to soil

liquefaction, liquefaction-induced settlement and landsliding, and soil

slope failure in foundations and embankments; and (3) landsliding and

[[Page 45647]]

collapse of surrounding structures.29 The background

document supporting this section of the rule provides examples of the

potential adverse effects on CKD landfill units that may occur in

seismic impact zones. The Agency believes that these failures may

result in contamination of air, ground water, surface water and soil.

Therefore, in order to protect human health and the environment, all

containment structures must be designed to withstand the stresses

created by peak ground acceleration at the site from the maximum

earthquake based on regional studies and site-specific

analyses.30

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\29\ See Livermore Associated Research Group, Inc. 1982. Seismic

Location Standards. Prepared for U.S. Environmental Protection

Agency, Office of Solid Waste, Washington, D.C.

\30\ To determine whether a CKD landfill unit is in a seismic

zone, persons managing CKD waste should look at maps depiciting the

potential seismic activity across the United States that have been

prepared by the United States Geological Survey (Open File Report

82-1033).

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The process designing earthquake-resistant components may be

divided into three steps: (1) Determining expected peak ground

acceleration at the site due to a maximum quake, based on regional

studies and site-specific seismic risk analysis; (2) determining site-

specific seismic hazards (e.g., soil liquefaction); and (3) designing

the facility to withstand peak ground accelerations. Various methods

for accomplishing the above tasks appropriate to individual CKD

landfill units should be selected by the person managing CKD waste,

subject to regulatory agency approval.

f. Unstable Areas

EPA is also proposing that persons managing CKD waste in new and

existing CKD landfill units located in unstable areas must demonstrate

the structural integrity of the unit to the EPA Regional Administrator

(or the State, in authorized States). This demonstration must show that

engineering measures have been incorporated into the unit's design to

mitigate the potential adverse structural impacts on the structural

components of the unit that may result from subsidence, slope failure,

or other mass movements in unstable areas. For purposes of this

section, structural components include liners, leachate collection

systems, and final covers.

EPA is particularly concerned with CKD landfill units located in

areas of karst terrain. For purposes of this section, karst terrain

means an area where karst landscape, with its characteristic

hydrogeology and/or landforms is developed. In karst terrain, ground-

water flow generally occurs through an open system with both diffuse

and conduit flow end member components, and typically has rapid ground-

water flow velocities which exceed Darcian flow

velocities.31 Composed of limestone, dolomite, gypsum and

other soluble rock, karst terrain typically has well developed

secondary porosity enhanced by dissolution. Landforms found in karst

terrain include, but are not limited to, sinkholes, sinking streams,

caves, springs and blind valleys. Karst terrains always include one or

more springs for each ground-water basin, and underground streams

except where ground-water flow is diffuse or the host rock has

megaporosity.

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\31\ Darcian flow means ground-water flow which follows Darcy's

law, where the specific discharge is proportional to the hydraulic

gradient. Darcian ground-water flow is typically linear and laminar,

travels from 1 x 10-11 to 1 x 102

centimeters per second, and is characteristic of ground-water flow

through granular porous media.

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The regulatory definition of karst terrain in today's proposal

expands beyond the obvious landform features typically associated with

mature karst topography (e.g., sinkholes and caves). Not all waste

disposal sites overlying carbonate aquifers exhibit mature features of

well-developed karst, but, nevertheless, may overlie karst aquifers

with well developed conduit systems in which turbulent flow regimes

dominate. Karst systems are commonly mantled by thick regolith, or

partially covered by caprock which may exhibit a topography that is not

characteristic of a traditional karst setting. If the regulatory

definition of karst relies solely on apparent karst landform features,

persons managing CKD waste at facilities situated in karst settings

with no apparent on-site karst features could claim that their

facilities are not in karst terrain and, therefore, do not overlie a

karst aquifer. EPA solicits comment on today's proposed definition of

karst terrain and the proposed approach for identifying karst hydrology

within and around facility property.

The fundamental hydrologic difference between karst and non-karst

terrain is ground-water flow velocity in excess of velocities that are

typical of porous media (i.e., Darcian flow velocities). A well

developed karst aquifer usually has a ground-water flow velocity orders

of magnitude greater than a porous media aquifer. The most important

aspect of open karst systems is that the dominant basin-wide component

is rapid turbulent ground-water movement, that is non-Darcian flow,

through conduits to one or more springs that can vary in magnitude

based on the size of the basin and seasonable ground-water conditions.

The magnitude of the springs are largely a function of the size of the

ground-water basin and aquifer recharge.

Accordingly, before a CKD landfill unit can be sited in a potential

karst terrain, a person managing CKD waste must first verify and

certify that the facility is situated in a karst terrain based on the

revised definition of karst terrain pursuant to Sec. 259.16(b)(1).

Today's rule proposes that prior to construction of a CKD landfill in

carbonate terrain, a karst ground-water investigation must be conducted

to define the direction of ground-water flow, and points of discharge

for the karst ground-water basin(s) the facility may affect. The karst

ground-water investigation shall include a dye tracer study to identify

springs which are hydrologically related to the karst ground-water

basin potentially affected by the unit. The verification of a karst

terrain may include, but not necessarily be limited to, a review of the

available literature. If the literature fails to provide conclusive

evidence that the facility does not overlie a karst terrain, a basin-

wide field study should be implemented, even if the discharge points of

the basin exist beyond the facility boundary, to identify all potential

springs from which ground water passing beneath the CKD landfill unit

may discharge. Certification may be obtained from an independent

professional ground-water scientist, from the EPA Regional

Administrator, or from the State, in authorized States.

After verification, the person managing CKD waste must locate

background and intermediate sampling locations, and downgradient

springs or ground-water monitoring wells for detection monitoring

pursuant to Sec. 259.44(a) and Sec. 259.45(b) for assessment

monitoring. The person managing CKD waste must establish a ground-water

monitoring system pursuant to Sec. 259.41(a) that incorporates spring

monitoring. The Agency believes that this will generally necessitate:

(1) a field study to conduct an inventory of karst features and locate

springs; (2) quantitative tracer studies to verify flow path, time-of-

travel, and duration of the dye plume; (3) the regular monitoring of

chemographs and hydrographs of springs and monitoring wells; and (4)

the development of a sampling strategy based on the unique fate and

transport characteristics of the toxic constituents in CKD and

hydrology of the karst aquifer, that is capable of detecting releases

from the CKD landfill unit.

EPA believes it is important to include quantitative dye tracer

studies in any analysis of karst in order to

[[Page 45648]]

determine the time of travel and duration of the dye plume. Such data

are essential inputs to construction of a model of contaminant

migration through the aquifer. The contaminant model is predicated on

the dye behaving similarly to a contaminant in its dissolved phase or

in suspension adsorbed to colloids. Information on the time of travel

and duration of the dye plume would be compared to data from the storm

hydrograph and chemograph to identify optimum sampling intervals. The

Agency solicits comments on practical difficulties with dye studies and

characterizing karst terrain, and whether there are other alternative

approaches to ensure protection of human health and the environment.

Some areas of karst terrain may be prone to subsidence because of

natural subsurface conditions. Limestone and dolomite are slightly

soluble in water, and the solution process can enlarge existing

fractures, joints and other voids creating sinkholes and caves.

Potential caverns and karst pinnacles in the soil and bedrock may

eventually lead to collapse or puncture of the landfill liner due to

excessive overburden or settling. Accordingly, today's rule proposes

that the ground-water investigation shall also include an inventory of

karst features within and around facility property to identify areas

prone to surface subsidence or mass movement.

4. Performance-Based Standard for the Protection of Ground Water

a. Overview

To provide maximum flexibility while ensuring protectiveness, EPA

is proposing two types of standards relating to groundwater protection:

a traditional technology standard, specifying landfill design and other

technical requirements, and a more flexible performance-based standard

for facilities that wish to utilize a design or technology that they

believe will meet the performance standard. To ensure that it is

complying with the standards, a person managing CKD waste may choose

either to propose an alternative approach to the EPA Regional

Administrator (or the State, in authorized States), or may implement

the technology standards. EPA may approve the alternative if the Agency

concludes the alternative will meet a more general performance standard

described below.

With respect to ground water protection, EPA is proposing that the

unit design must ensure that exceedances of a ground-water protection

standard not occur at the relevant point of compliance. This standard

would apply to the metal constituents listed in Appendix VIII of Part

261 (antimony, arsenic, barium, beryllium, cadmium, chromium (total),

lead, mercury, selenium, silver, and thallium). For each constituent,

the standard would be as follows: (1) if available, the maximum

contaminant level (MCL) established under section 1412 of the Safe

Drinking Water Act (see 40 CFR Part 141); (2) for constituents with

concentration levels lower than background, the background level; and

(3) for constituents with no MCLs, an alternative risk-based number or,

(in an unauthorized State) other appropriate level established by the

EPA Regional Administrator. The Agency solicits comment on the adequacy

of using MCLs to define limits for metals in ground water at the point

of compliance, and whether or not health-based numbers (HBNs) rather

than MCLs should be used as a primary groundwater protection standard.

While, EPA's Subtitle D groundwater protection standards are based on

MCLs, the Agency's hazardous waste listing determinations are

traditionally based on HBNs. The primary difference between MCLs and

HBNs is that HBNs are derived based solely on health effects whereas

several factors in addition to health effects are considered in the

development of MCLs. Development of MCLs requires an evaluation of: (1)

The availability and cost of analytical methods; (2) the availability

and performance of technologies and other factors relative to

feasibility and identifying those that are ``best'; and, (3) an

assessment of the costs of the application of technologies to achieve

various concentrations. Therefore, MCLs may be more or less

conservative than HBNs corresponding to the Agency's hazardous waste

listing risk range of 10E-4 to 10E-6 for carcinogens and an HQ of 1 for

non-carcinogens.

EPA is proposing today that facilities that wish to propose a

design to comply with the performance standard must submit a proposed

plan to implement the performance standard for approval by a regulatory

agency. EPA will provide such oversight in unauthorized States.

Authorized States, on the other hand, may be more stringent and are not

required to adopt today's proposed performance standard approach. If a

State chooses not to provide such review, compliance with the

technology standards would be required (since there is no mechanism for

approving an alternative approach). EPA strongly urges States to

provide the option of a performance standard. Such a standard would

protect human health and the environment and minimize the cost of

compliance by allowing facilities to tailor ground-water controls to

site-specific conditions.

b. Performance Standard and the Point of Compliance

The MCL is the maximum permissible level of a contaminant in water

which is delivered to any user of a public water system, and is a

standard for evaluating the potability of water. It is the traditional

measure used by the Agency to protect the nation's public drinking

water supplies (see 40 CFR Parts 141-143 National Drinking Water

Regulations). MCLs would be measured at the point of compliance (POC),

defined as the closest practical distance from the unit boundary, or at

an alternative point chosen by the EPA Regional Administrator (or the

State, in authorized States). The alternative POC must be on facility

property and be no more than 150 meters from the unit boundary. In

allowing for an alternative POC, the Agency's rationale is to allow

greater flexibility for a State to set design requirements based on the

site-specific factors (for example, see Sec. 257.3-4(b)(1)(i) through

(vii)).

5. Technology-Based Standards for the Protection of Ground Water

EPA is proposing that design criteria similar to those for MSWLFs

under the Subtitle D program (Solid Waste Disposal Facility Criteria,

56 FR 50978, October 9, 1991) be adopted with certain modifications for

ground-water monitoring (see Sec. 259.40) and remediation. For

facilities complying with the technology-based standards for the

protection of ground water, any new CKD waste management unit or

lateral expansion of an existing unit must be constructed with a

composite liner and a leachate collection and removal system (LCS) that

is designed and constructed to maintain less than a 30 cm depth of

leachate over the liner. The composite liner must consist of two

components: an upper flexible membrane liner (FML) with a minimum

thickness of 30-mil, and a lower component consisting of at least two

feet of compacted clay with a hydraulic conductivity of no more than 1

x 10-7 cm/sec. In selecting this uniform design, EPA's goal

was to identify one that would provide adequate protection in all

locations.

The Agency believes the technology-based standards proposed in

today's rule will be protective of ground-water resources. Liners will

prevent leachate from seeping from the landfill and entering the

aquifer. The FML must

[[Page 45649]]

have a minimum thickness of 30-mils and be installed in direct and

uniform contact with the lower clay component to ensure adequate liner

performance, including being able to withstand the stress of

construction (see U.S. EPA RREL, Lining of Waste Containment and Other

Impoundment Facilities EPA/600/2-88/052. September 1988). Compacted

clay liners must be at least two feet thick to ensure a high

probability of having a hydraulic conductivity of 1 x 10-7

cm/sec. Functionally, both the FML and lower clay component are

necessary to retard the migration of contaminants into the subsoil. The

FML component would provide a highly impermeable layer to maximize

leachate collection and removal. The compacted clay liner would adsorb

and attenuate pollutants in the event of FML liner failure.

A LCS is necessary to relieve the hydraulic pressure within the

landfill which could drive leachate migration through the base of the

landfill. LCS design normally consists of a permeable material placed

on a sloping surface so as to allow leachate to be removed and

collected. Large units may also have a pipe drainage system. Sloping

the LCS towards a sump minimizes any downward flow, and reduces the

amount of leachate leaving the LCS.

The Agency seeks comments on the effectiveness of various liner

thicknesses and materials in preventing the migration of the hazardous

constituents of CKD to groundwater. Of particular interest to the

Agency is the effectiveness of use of CKD as a liner or cap material.

CKD may be a suitable material for use as a liner or cap material

because of its cementitious properties. Studies on CKD obtained by the

Agency suggests that very low hydraulic conductivities (less than 1 x

10-7 cm/sec) are readily achievable in the laboratory, and

in field trials using heavy equipment to compress CKD to high

densities.\32\ However, the Agency also has contravening information

from one site visit and two case studies where CKD has been used as a

cap material \33\ which suggests that compaction control is difficult

to maintain over an area that is acres in size. Nevertheless, EPA is

not proposing today that CKD be banned from use as a liner or cap

material. Rather, it can be used as part of a unit design if the person

managing CKD waste can demonstrate that the design meets the

performance standard for ground water, including establishing that the

material will maintain integrity over long periods of time and,

therefore, has a low potential for release of contaminants.

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\32\ See Todres, H.A., 1992. Cement Kiln Dust: Field Compaction

and Resulting Permeability. Research and Development Bulletin

RD106T, Portland Cement Association, Skokie, Illinois. 47p; and,

Todres, H.A., Mishulovich, A., and Ahmed, J. 1992. Cement Kiln Dust

Management: Permeability. Research and Development Bulletin RD103T,

Portland Cement Association, Skokie, Illinois. 9p.

\33\ See Spectra Engineering, P.C., 1995. Lehigh Portland Cement

Company, Alsen Dust Disposal Facility, Closure Certification Report.

Prepared for Lehigh Portland Cement Company, Cementon Plant,

Cementon, New York. See also letter from Thomas M. Polasek, P.E.,

Michigan Department of Environmental Quality, to Frank Davis,

Lafarge Corporation, re: Consent Judgment Compliance, October 10,

1996.

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6. Requirements for Ground-water Monitoring

EPA is proposing that ground-water monitoring be required for all

new and existing CKD management units, to detect the presence of

regulated constituents in the ground water. The ground-water monitoring

and corrective action requirements proposed today are based on

requirements promulgated under Part 258 for MSWLFs and hazardous waste

regulations under Part 264--Subpart F for Solid Waste Management Units.

The ground-water monitoring system must include at a minimum one up

gradient and three down gradient wells. The down gradient wells must be

located not farther than 150 meters from the unit boundary at the

relevant POC specified by the EPA Regional Administrator (or the State,

in authorized States). The ground-water monitoring system must be

capable of ascertaining the quality of background ground water that has

not been affected by releases from the unit, and assessing the quality

of ground water passing the relevant POC, as certified by a qualified

ground-water scientist. The ground-water monitoring program must

include consistent sampling and analysis procedures that are designed

to ensure monitoring results that provide an accurate representation of

ground-water quality at the background and down gradient wells.

For facilities located in karst terrain, EPA is also proposing that

the ground-water monitoring strategy include, where necessary, springs

which are the ultimate discharge points of the karst ground-water basin

in which the facility is situated. In karst terrain, point-of-

compliance ground-water monitoring wells may not detect a point source

release from a CKD management unit based on failure of the monitoring

wells to intersect the conduit through which the contaminant plume

passes. While monitoring wells are appropriate, they are not fail-safe.

Consequently, discharge points of the karst ground-water basin should

be incorporated into the overall monitoring strategy to detect a

release. In today's rule, EPA is proposing that the EPA Regional

Administrator (or the State, in authorized States), in addition to

specifying the relevant POC, may also specify ground-water monitoring

at discharge points of the karst ground-water basin potentially

affected by releases from the CKD waste management unit.

EPA is proposing two types of monitoring: detection monitoring and

assessment monitoring. Under proposed Sec. 259.44, persons managing CKD

waste in a CKD waste management unit will be required to undertake a

ground-water detection monitoring program, similar to that described

under Sec. 258.54 of the MSWLF rule. In a departure from the MSWLF

rule, EPA is proposing to require detection monitoring only for the

following parameters: pH, conductivity, total dissolved solids,

potassium, chloride, sodium, and sulfate. These detection parameters

are easily measured and should provide a reliable indication of

inorganic releases from the CKD waste management unit to ground water.

The Agency solicits comment on the adequacy of these detection

parameters for monitoring releases and whether metal constituents are

necessary.

If detection monitoring indicates a statistically significant

increase over background for one or more of the detection parameters

listed above, under proposed Sec. 259.45, a person managing CKD waste

is required to implement an assessment monitoring program, similar to

that described in Sec. 258.55 of the MSWLF rule. In another proposed

departure from the MSWLF rule, today's proposed rule does not require a

scan for the hazardous constituents listed under part 258, Appendix II.

Instead persons managing CKD under today's proposed rule would be

required to sample and analyze the ground water for only the inorganic

constituents listed in Appendix VIII of Part 261 (antimony, arsenic,

barium, beryllium, cadmium, chromium (total), lead, mercury, nickel,

selenium, silver, and thallium).

Because this proposal requires ground-water monitoring at new and

existing CKD landfill units, today's action effectively prohibits the

location of such units in areas where subsurface conditions prevent

monitoring of subsurface contaminant migration from the landfill unit.

EPA anticipates that the Regional Administrators (or authorized States)

will not issue an operating permit for CKD landfill units located in

areas where subsurface monitoring is impossible. Geologic

[[Page 45650]]

settings that could preclude effective ground-water monitoring include

areas of limestone bedrock in mature karst settings, with complex

networks of conduits, fractures, and joints which impede accurate

prediction of ground-water flow. The Agency considers it the

responsibility of the persons managing CKD waste to prove that a

landfill can be effectively monitored.

7. Corrective Action

Today's proposal establishes corrective action steps similar to

Sec. 258.56 of the MSWLF rule. Within 90 days of finding that any of

the part 261 inorganic constituents (see previous section) have been

detected at a statistically significant level exceeding the ground-

water protection standards as defined under Sec. 259.45(h), the persons

managing CKD waste must initiate an assessment of corrective measures.

Such an assessment must be completed within 90 days, or within an

alternative period of time decided by the EPA Regional Administrator,

in accordance with Sec. 259.46. Today's proposal allows for swift

remediation of a ground-water problem, yet provides flexibility for

selecting and implementing the corrective remedy.

Under proposed Sec. 259.47 and Sec. 259.48, the selection of a

remedy and implementation of the corrective action program must be

completed in accordance with those procedures which are similar to

those enumerated in 40 CFR 258.57 and 258.58 for MSWLFs. These

requirements only apply to those hazardous constituents that are likely

to be present in CKD as previously described. An exceedance of today's

proposed ground-water protection standards would not immediately result

in classification of such CKD as mismanaged. If a person managing CKD

waste, however, failed to take the necessary corrective action after

detecting an exceedance, CKD would be considered mismanaged and,

therefore, hazardous waste. The Agency solicits comment regarding the

time periods in which remedial activities must be initiated, and

whether or not today's proposed minimum time periods are appropriate

given the widely varying circumstances likely to be encountered at

facilities requiring corrective action.

In today's rule the Agency is not proposing facility-wide

corrective action standards for the management of CKD. Instead, EPA

proposes to require corrective action at units which are actively

managing CKD. EPA believes that the costs associated with requiring

corrective action at all solid waste management units that may happen

to be located at a CKD facility make it inappropriate to impose such a

requirement. Where releases from such units have occurred, other state

law authorities and the Federal imminent hazard authorities under

section 7003 of RCRA or section 106 of CERCLA, will be adequate to

address any threats to human health and the environment. (The handling

of corrective action at facilities that become subject to today's

proposed Subtitle C standards is discussed in Section V.B.--

Implementation of part 259 and RCRA Subtitle C Backup Standards.)

B. Standards for Fugitive CKD Emissions

1. The Need to Limit Fugitive CKD Emissions

In the Agency's follow-up work leading to the September 1994 NODA

(see 59 FR 47133, September 14, 1994), EPA found evidence of possible

risk to human health due to the fine particulate nature of inhaled

dust. Particulate matter is of health concern because fine particles

such as CKD can penetrate into the sensitive regions of the respiratory

tract and cause respiratory illness. Negative effects associated with

exposure to particulate matter include premature death, hospital

admissions from respiratory ailments, and increased respiratory

symptoms such as persistent coughs, phlegm, wheezing, and physical

discomfort. Long-term exposure to particulate matter may increase the

rate of respiratory and cardiovascular illness and reduce life span.

Although the Agency's direct inhalation exposure modeling studies

described in the RTC did not indicate significant risk from inhaled

chemical constituents in CKD, subsequent screening-level modeling on

five case study plants indicated that windblown dust from uncontrolled

CKD waste management units (uncovered and dry CKD piles) could exceed

EPA's health-based PM10 fine particulate (10 microns or

less) National Ambient Air Quality Standard(NAAQS) 34 at

plant boundaries, and potentially at nearby residences.

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\34\ The level of the national primary and secondary 24-hour

ambient air quality standards for PM10 is 150 micrograms

per cubic meter g/m\3\), and 65 g/m\3\ for

PM25, 24-hour average concentration. The standards are

attained when the expected number of days per calendar year with a

24-hour average concentration above 150 g/m\3\ for

PM10, and above 65 g/m\3\ for PM25,

as determined in accordance with Appendix K to 40 CFR part 50, is

equal to or less than one. The level of the national primary and

secondary annual standards for PM10 is 50 micrograms per

cubic meter (g/m\3\), and 15 g/m\3\ for

PM25, annual arithmetic mean. The standards are attained

when the expected annual arithmetic mean concentration, as

determined in accordance with Appendix K to part 50, is less than or

equal to 50 g/m\3\ for PM10 and 15 g/

m\3\ for PM25.

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Results from a subsequent extension of this work to a larger sample

of 52 cement plants suggest that 28 of the plants could exceed NAAQS

PM10 standards at plant boundaries, if the plants do not

have effective dust control mechanisms in place. The Agency recognizes

that dust from mining and quarry operations could contribute to the

particulate emissions from a cement plant; however, other evidence

(i.e., damage cases) indicates that fugitive CKD emissions are a

substantial contributor to environmental damages in the form of air

quality degradation.

Additionally, particulate emissions of fugitive dust are the major

contributor of CKD to EPA's indirect foodchain pathway model. The

Agency's quantitative modeling of ``indirect'' food chain pathways,

both aquatic and agricultural, indicates potential human health

effects, both cancer and non-cancer. A wide range of chemical

constituents, including arsenic, cadmium, chromium, barium, thallium,

lead, and dioxins, were indicated as constituents of concern at various

plants. Because some CKD disposal units are located near, and in some

instances immediately adjacent to, farm fields, rural residences with

gardens, or surface waters containing fish, there is potential for

indirect risk from the consumption of CKD-contaminated beef, vegetables

and fish, as well as ingestion of CKD-contaminated water during

recreational swimming.

Although quantitative risks presently can not be estimated, these

initial modeling results relating to fine particulates suggest cause

for concern and argue for further attention to this source of fugitive

dust. Consequently, the Agency believes it is necessary to impose

additional controls on fugitive emissions under authority provided by

RCRA section 3004(n).

2. Applicability

EPA is proposing air protection standards to limit fugitive CKD

emissions for all new and existing CKD waste landfill units, except

units closed prior to the effective date of the final rule. Any

expansion of an existing CKD landfill unit, defined as any lateral or

vertical expansion of the waste boundary of an existing landfill unit,

must meet today's proposed requirements. Under this proposed

definition, any area of any existing unit that receives waste after the

effective date of this rule is an expansion. EPA is also proposing that

interim storage units, such as containers or buildings which contain

CKD destined for recycling or sale, must comply with the air

performance standards.

[[Page 45651]]

Consistent with controls proposed today for ground water, the

Agency is not proposing to require fugitive dust controls for the old,

inactive portions of existing CKD landfills. However, EPA solicits

comment on applying air controls to the entire active unit, including

any inactive area of a CKD landfill with an expansion.

These proposed standards could be met in one of two ways. First, a

person managing CKD waste could obtain a determination from the EPA

Regional Administrator (or from the State, in authorized States), that

a management practice or design meets the performance standard,

providing adequate assurance that the unit is managed to control wind

dispersal of particulate matter. Second, the person managing CKD waste

could design units according to technology-based standards outlined

below, so as to obviate the need for such a demonstration.

3. Performance Standard for the Protection of Air

Under today's proposal, unit design must ensure that wind dispersal

of particulate material (PM) is controlled. The specific performance

standard for air is that the persons managing CKD must cover or

otherwise manage the unit to control wind dispersal of CKD waste. This

standard would apply to solid PM that becomes airborne directly or

indirectly as a result of CKD handling procedures. The most common

sources of PM at cement manufacturing facilities to which this standard

applies includes vehicular traffic on unpaved roads or on CKD waste

management units, and wind erosion from waste management units. This

standard would not apply to CKD emitted from an exhaust stack.

The Agency understands that methods for controlling fugitive dust

will vary depending on factors such as geographic location, climate,

facility design, and CKD management method. While the technology-based

standards of conditioning CKD, using covers, watering, and use of

tanks, containers, or buildings for temporary storage, meets the

performance standard, other techniques and technologies may be as or

more effective. Therefore, today's proposal provides persons managing

CKD waste, working with regulatory agencies, with substantial

flexibility to determine the appropriate method to control fugitive

emissions based on facility-specific conditions.

To demonstrate compliance with the performance standard for the

protection of air, EPA is proposing that persons managing CKD waste in

new and existing CKD landfills, temporary storage areas, and trucks

provide cover or otherwise manage the CKD such that equivalent control

exists to that provided by daily cover of the landfill unit.

Additionally, if landfill units, roads, temporary storage areas, and

trucks are managed with no visible fugitive emissions of CKD, the

Agency would view that the performance standard is met. The Agency

solicits comment regarding the effectiveness of various fugitive dust

control methods in demonstrating compliance with the performance

standard for air so that EPA can provide comprehensive guidance to

persons managing CKD and to staff at regulatory agencies who would

implement today's proposed rule.

4. Technology-Based Standards for Fugitive Dust Control

a. Conditioning

For facilities complying with the technology-based standards, EPA

is proposing that CKD managed in landfills must be emplaced as

conditioned CKD. For purposes of this section, conditioned CKD means

cement kiln dust that has been compacted in the field at appropriate

moisture content using moderate to heavy equipment to attain 95% of the

standard Proctor maximum dry density value according to ASTM D 698 or D

1557 test methods. Such conditioning can be achieved by mixing the CKD

with water on a continuous or batch basis, such as pug-milling,

followed by compaction. The material should be spread in lifts of

uniform thickness and compacted to the required density with

appropriate equipment (e.g., a heavy sheep-foot roller). The compaction

of moist CKD, coupled with the waste's natural cementitious properties,

enables individual waste particles to bond together, thus greatly

reducing the availability of particulate material for air dispersal,

and, therefore, this standard is protective for fugitive dust from

landfills. In addition, the bonding can serve to decrease the leaching

of contaminants from CKD.

b. Covers

The Agency is also proposing that disposed CKD be covered with

material at the end of each operating day sufficient to prevent blowing

dust. EPA believes that cover material applied at the end of each

operating day over the active face of the CKD landfill will prevent the

entrainment of fugitive dust, and is a more effective practice for dust

suppression than frequent wetting and watering.35 The cover

must be constructed of materials that have appropriate physical and

chemical properties, and sufficient strength and thickness to prevent

failure due to physical contact with CKD, climatic conditions, the

stress of installation, and the stress of daily operation. Similarly,

EPA is proposing that CKD transported in trucks on or off the facility

be covered to minimize fugitive emissions of CKD. Alternative materials

or actions may be approved by the EPA Regional Administrator (or the

State, in authorized States), as long as the person managing CKD waste

makes a demonstration that the alternative meets the performance

standard.

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\35\ Although wetting and watering is a common fugitive dust

suppression practice at CKD landfills, the persistent releases of

fugitive CKD reported in the RTC suggest that frequent wetting alone

is not sufficient to prevent blowing dust.

---------------------------------------------------------------------------

c. Wetting

Wetting of CKD on roads is not required in today's proposed

performance-based standards. EPA believes, however, that consistent

wetting and watering of unpaved roads, when used in conjunction with

other air control technologies, can reduce releases of fugitive

emissions from facilities that manage CKD. Data from an EPA study of

fugitive dust emissions from cement plants and potential control

measures indicates that fugitive dust emissions from unpaved roads can

be significantly reduced by increasing the moisture content of the

dust. However, the wetting of roads by itself will not meet today's

proposed performance standard for air.

The Agency solicits comments on the effectiveness of these and

other methods for controlling fugitive emissions of CKD.

d. Temporary Storage

The Agency today is proposing that CKD destined for temporary

storage prior to recycling, sale, or disposal not be placed in land-

based units, but in tanks, containers, or buildings. CKD would not be

considered a hazardous waste provided the storage that precedes sale or

recycling provides adequate control of fugitive dust. An acceptable

containment unit must be a man-made structure with a foundation

constructed of non-earthen materials, have walls (which may be

removable), and have a roof suitable for diverting rainwater away from

the foundation. In considering these criteria for containers and

buildings, EPA is placing special emphasis upon practical

considerations, such as the need to transport materials in and out of

the unit in a reasonable fashion. The Agency would not require that

these units meet full Subtitle C

[[Page 45652]]

requirements for storage of hazardous wastes as outlined in parts 264

and 265 subparts I and J.

C. Closure

In today's proposed rule, EPA is requiring that new and existing

CKD landfill units, including expansions be closed in accordance with

specified standards, and that units be monitored and maintained after

closure. Closure and post-closure plans describing these activities are

to be prepared to comply with a minimum set of procedural requirements.

As described in the damage cases supporting this rule, improperly

closed CKD landfills have the potential for contaminating the

environment due to inadequate controls to contain the waste. For

example, in one damage case, CKD wastes remained exposed due, in part,

to failure to install a proper cap or insulate the waste from the

erosive wave action of Lake Huron.

EPA proposes that all persons managing CKD waste in CKD landfill

units must install a final cover designed to minimize infiltration and

promote drainage from its surface while minimizing erosion. It must

also be designed so that settling and subsidence are accommodated to

minimize the potential for disruption of continuity and function of the

final cover. The Agency believes that placement of a final cover over

closed portions of a CKD landfill is necessary to minimize the

infiltration of rainwater, minimize the dispersal of CKD waste through

physical interaction, and minimize the need for further maintenance at

the facility through the post-closure period and beyond. The

infiltration layer must be a minimum of 18 inches of earthen material

that has a hydraulic conductivity of less than or equal to the bottom

liner system, or no greater than 1 x 10-5 cm/sec,

whichever is less. The erosion layer must have a sufficient thickness

to sustain native plant growth. Alternative final cover designs may be

approved by the EPA Regional Administrator (or the State, in authorized

States), if the cover layers achieve the same objectives as the

specified design in this proposed rule.

D. Post-Closure Care

Today's proposed rule also requires that post-closure care be

conducted for a period of 30 years after the closure of each CKD

landfill unit. Post-closure care consists of maintaining the

effectiveness of the final cover and continuing ground-water monitoring

and leachate management to control the formation and release of

leachate into the environment. Routine maintenance of the integrity and

effectiveness of the final cover is necessary to prevent liquids from

penetrating into the closed landfill and creating the potential for

leachate migration.

EPA is proposing in today's rule to give the EPA Regional

Administrator (or the State, in authorized States), discretion to

reduce or extend the length of the post-closure period based on site-

specific demonstrations. The Agency is concerned that 30 years may be

excessive or insufficient to detect releases at some landfills.

Therefore, the Agency wants to ensure that any potential release will

be detected regardless of when it occurs.

Required activities in today's proposed rule include repairs to the

final cover to correct the effects of settling, subsidence, and

erosion, and preventing run-on and run-off from damaging the cover.

Cover maintenance also includes periodic cap replacement, which is

necessary to remediate the effects of routine deterioration. The Agency

believes that these activities will minimize liquids in CKD landfills

and are the minimum steps necessary to protect human health and the

environment in the long term.

Today's proposal under Sec. 259.50 also requires ground-water

monitoring and maintenance of the ground-water monitoring system during

the post-closure care period. The fundamental purpose of monitoring

during the post-closure care period is to detect ground-water

contamination in a timely fashion should the CKD waste containment

structure fail, and to trigger corrective action activities as soon as

contamination occurs. Long-term monitoring is essential to detect

releases due to catastrophic failure or design and installation errors

(e.g., tearing of liners due to ground movement).

E. Closure/Post--Closure Planning Requirements

Today's proposed rule also requires preparation of closure and

post-closure plans describing activities that will be undertaken to

close each CKD landfill unit properly and maintain them after closure.

These plans must be prepared and placed in the facility operating

record no later than the effective date of this rule, or the date of

initial receipt of the waste, whichever is later.

The closure and post-closure care standards also include certain

procedural requirements. First, prior to closing of each landfill unit,

the EPA Regional Administrator (or the State, in authorized States)

must be notified and the notification must be placed in the facility

operating record. Second, closure of the landfill unit must begin

within 30 days after the date of final receipt of CKD waste and closure

complete within 180 days of receipt of the last shipment of waste.

Extensions to these deadlines may be approved for good cause by the EPA

Regional Administrator (or the State, in authorized States). Third,

following closure of the facility, a notation in the deed to the

property must be recorded that indicates the property has been used for

CKD disposal. Finally, the EPA Regional Administrator (or the State, in

authorized States) must be notified and a certification must be placed

in the facility operating record that verifies that closure and post-

closure activities have been conducted in accordance with closure and

post-closure plans. The certification must be signed by an independent

registered professional engineer, or approved by the EPA Regional

Administrator (or the State, in authorized States).

F. Financial Assurance

In today's proposed rule, a demonstration of financial assurance is

required for the costs of conducting closure, post-closure care, and,

if applicable, corrective action for known releases. The proposed

financial assurance requirements are patterned after the financial

assurance provisions for municipal solid waste landfill facilities

(MSWLFs) under Subtitle D. (see Secs. 258.71 to 258.75).

The purposes of financial assurance are to ensure that the owner or

operator of a CKD landfill unit adequately plans for the future costs

of closure, post-closure care, and corrective action for known

releases, and to ensure that adequate funds will be available when

needed to cover the costs if the owner or operator is unwilling or

unable to do so. To demonstrate to the EPA Regional Administrator (or

the State, in authorized States) that it has planned for future costs,

written cost estimates must be prepared. These cost estimates would

serve as the basis for determining the amount of financial assura

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