# Standards for the Management of Cement Kiln Dust > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A99-20546 ## Record - **Collection:** Federal Register - **Document type:** Proposed Rule - **Published:** August 20, 1999 - **Citation:** 64 FR 45632 ## Text 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. ----------------------------------------------------------------------- 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 [[Page 45633]] 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\ --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- 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\ --------------------------------------------------------------------------- \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). --------------------------------------------------------------------------- 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\ --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- 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\ --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- 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. --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- 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\ --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- 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\ --------------------------------------------------------------------------- \9\ These documents are available in the RIC docket (Nos. F-94- RCKA-FFFFF, F-94-RC2A-S0019 and -S0019.A). --------------------------------------------------------------------------- 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. --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- 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. --------------------------------------------------------------------------- \11\ EPA hazardous waste identification rules do not include a characteristic or definition for solid corrosives. --------------------------------------------------------------------------- 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. --------------------------------------------------------------------------- \12\ Supporting documentation for this analysis can be found in Chapter 7 of the RTC--Existing Regulatory Controls on CKD Management. --------------------------------------------------------------------------- 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. --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- \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). --------------------------------------------------------------------------- [[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. --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- 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. --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- 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. --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- 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 --------------------------------------------------------------------------- \20\ The cement industry's proposed management practices (version 6/1/5), see RIC docket No. F-99-CKDP-S0031. --------------------------------------------------------------------------- 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. --------------------------------------------------------------------------- \21\ For a copy of the MOU, see RIC docket No. F-99-CKDP-S0107. --------------------------------------------------------------------------- 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. --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- 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. --------------------------------------------------------------------------- \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), --------------------------------------------------------------------------- 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. --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- 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. --------------------------------------------------------------------------- \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.'' --------------------------------------------------------------------------- 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 --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- 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 --------------------------------------------------------------------------- \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). --------------------------------------------------------------------------- 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. --------------------------------------------------------------------------- \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. --------------------------------------------------------------------------- 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 re [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A99-20546. Public record. Not legal advice.