6 CCR 1007-3-8.18 - Basis and Purpose

These amendments to 6 CCR 1007-3, Parts 260, 264, and 100 are made pursuant to the authority granted to the Hazardous Waste Commission in section 25-15-302(2), C.R.S. These amendments revise and finalize technical and procedural standards related to permitting and operation of hazardous waste incinerators. The amendments strengthen the requirements for burning hazardous wastes in these devices, and are responsive to a number of issues identified by the Governor's Hazardous Waste Incineration Advisory Committee, the Governor's Committee on Hazardous Waste Regulation, the Colorado Department of Public Health and Environment, federal, state and local officials, and concerns expressed by the public regarding this activity over the past several years.

The Commission acknowledges that not all issues related to hazardous waste incineration identified by the interested parties were resolved through this rule-making. Legislative action may be the most appropriate mechanism to address issues that lie outside the authority currently provided under the Colorado Hazardous Waste Act (CHWA). The issues of concern to the Commission, some of which were also identified in the Advisory Committee Report (reference #2 below), include: promulgation of air toxics standards through the Air Quality Control Commission; an operator certification program for hazardous waste incinerator operators; provide clear authority to the Department to deny permit applications based on an applicant's compliance history; technical assistance grants to local communities for review of incineration projects; and mandatory reductions in waste generation by industry.

In order to address deficiencies which had been identified in the existing regulatory framework for hazardous waste incineration, the Commission requested that the Department's Hazardous Materials and Waste Management Division (the Division) prepare draft revisions to the existing State hazardous waste incineration regulations, Part 264-Subpart O, and applicable sections of Part 100. In general, these revisions include the expanded performance-related standards' specified in the federal Boiler and Industrial Furnace (BIF) rule, 40 CFR Part 266 -Subpart H. However, a great deal of implementation guidance, research, and policy documents have been developed by the U.S. Environmental Protection Agency (EPA) since the BIF Rule was promulgated. These sources of information were used in conjunction with the BIF Rule to prepare these amendments. The Commission has adopted appropriate sections of the BIF Rule, and incorporated current national guidance, policy and practice to develop hazardous waste incinerator rules with enforceable standards which ensure protection of public health and the environment. The CHWA provides authority for rules which are more protective than EPA's rules, and this document identifies the basis for any such changes to the existing regulations through this rulemaking. In addition to any existing rules, the authority for the Department to require more stringent permit conditions in order to protect human health and the environment exists in the "omnibus" provision of 6 CCR 1007-3, §100.43(a)(2). These amendments ensure that Colorado is at least as stringent as the U.S. Environmental Protection Agency regulations, and are more stringent in a number of areas.

The Department submitted a proposed rulemaking to the Hazardous Waste Commission as draft language for discussion, dated July 27, 1994, which were noticed in the Colorado Register in August 1994. The Commission conducted the rulemaking hearings as a formal rulemaking process. There were initially three parties to the rulemaking: the Division, the U.S. Environmental Protection Agency (Region VIII), and the Sierra Club, a national environmental organization. The first hearing was held in Avondale, Colorado on October 18, 1994. The EPA subsequently dropped its formal party status, and submitted written testimony to the Division in support of the proposed amendments.

These proposed regulations do not address permitting, operation, or combustion of hazardous waste in boilers and industrial furnaces. Operation of these devices is regulated in Colorado by the U.S. Environmental Protection Agency under 40 CFR Part 266 - Subpart H.

STATUS OF HAZARDOUS WASTE INCINERATION IN COLORADO and EFFECT OF AMENDMENTS

One existing facility (ECOVA Corp, formerly Waste-Tech Services, Inc.) is permitted in Colorado to operate a research scale fluidized bed incinerator. This facility operates infrequently, and is not used for commercial destruction of waste. The Department will review information such as emissions and operating conditions regarding this facility to determine if permit modifications are necessary to protect human health and the environment as a result of these amendments. One facility (the U.S. Army-Pueblo Depot Activity) is seeking a permit to construct a hazardous waste incineration facility for the destruction of obsolete chemical munitions stored at the Depot. The permit application was submitted in June 1992, and is under review by the Department. Construction of this facility cannot begin until the Army has received a final State RCRA permit issued by the Department and a Certificate of Designation (CD) from Pueblo county. The U.S. Congress must also continue its approval and funding of the project. These amendments will, to some degree, affect this facility's application requirements and subsequent operating requirements, if a permit is issued. Since these amended regulations are generally consistent with EPA's national policy, the Army is aware of many of these new requirements, and is addressing the same or similar issues at other Chemical Demilitarization program sites, such as Tooele, Utah and Anniston, Alabama.

The Army operates a submerged quench incinerator (SQI) at the Rocky Mountain Arsenal (RMA) for destruction of wastes from clean-up activities at Basin F, a former waste disposal site. The Army was not required to pursue a State RCRA permit as it was approved under a four party agreement as a CERCLA Interim Response Action (IRA), for which EPA was lead regulatory Agency. The State of Colorado reviewed the project for compliance with the technical requirements of RCRA, such as 40 CFR Part 264 , Subpart O, under a CERCLA "ARAR" process. The SQI was constructed by Army contractors, operated by Army contractors under applicable requirements, and regulatory oversight is provided by the Department and EPA. It is not expected that these amended regulations will significantly affect operation of this facility, since a thorough site specific risk assessment, very similar to that required by these amendments, was conducted and emissions from the SQI met acceptable target levels. In addition, the SQI will not operate for an extended period of time. Its mission, which began in mid-1993, is to treat a specific volume of on-site wastes and is nearly complete.

REFERENCES

A number of sources were utilized in preparing these amendments to regulations for hazardous waste incineration. The following list contains the major sources of information on which the amendments are based, and these documents are available at the Division's records center for review upon request:

1. Boiler and Industrial Furnaces Rule- 40 CFR 266 -Subpart H (56 FR 7134, Feb. 21, 1991);
2. Recommendations of the Governor's Hazardous Waste Incineration Advisory Committee (11/91);
3. The Department's report to Governor Romer on hazardous waste incineration (11/5/91.);
4.
a) EPA's Draft Combustion Strategy (DCS) (May 1993);
b) EPA's Strategy for Hazardous Minimization and Combustion (November 1994);
5. Report of Committee on Hazardous Waste Regulation on the Boiler and Industrial Furnaces Rule-7/30/92;
6. Division memos to the Committee on Hazardous Waste Regulation dated April 20, 1992 and May 27, 1992;
7. Hearing and meeting record of the Committee on Hazardous Waste Regulation (February 1991 through July 1992);
8. New Source Performance Standards (NSPS) for Municipal Waste Combustors; Colorado Air Regulations No. 6.Part A, Subpart E(a) and Part B; 40 CFR 60 -Subpart E(a);
9. Materials provided as exhibits to the Division's preheating statement of September 8, 1994;
10. "Combustion Emissions Technical Resource Document" (CETRED), EPA530-R-94-014FINAL (May 1994);
11. "Municipal Waste Combustion Assessment: Technical Basis for Good Combustion Practice" ; EPA-600/ 8-89-063; (August 1989);
12. Proposed federal regulations for enhanced public participation at RCRA facilities. (June 2, 1994);
13. Proposed federal regulations for NSPS for municipal waste combustors (59 FR 48198, September 20, 1994).
14. The Commission's Rulemaking Hearing Record for rulemaking hearings of October 18, 1994, November 15, 1994, January 17, 1995, February 21, 1995, April 18, 1995, and May 16, 1995, including: Pre-hearing submittals and testimony of the parties to the hearings, and hearing minutes.
15. 40 CFR Part 761 -Polychlorinated Biphenyls (PCBs) Manufacturing, Processing, Distribution in Commerce, and use Prohibitions, Subpart D-Storage and Disposal (40 CFR 761.65(d)(3));.

AMENDMENTS

Each significant amendment to the existing regulations for hazardous waste incineration is listed in the following sections. A brief description of the revision, the basis for the revision, and a discussion of the background and purpose of the revision is provided.

THE FOLLOWING REVISIONS ARE INCORPORATED INTO 6 CCR 1007-3. PART 100

(1) REVISION: Addition of Pre- and Post- Trial Burn Risk Assessment requirements to application process (§ §100.22(c)(5) and (6)): These amendments require that facilities which submit an application to operate a hazardous waste incineration (HWL) facility provide a two phase assessment of risk for stack emissions from the facility.

BASIS: References # 4, 5, 6, 9.

DISCUSSION: The EPA has implemented the use of pre- and post-trial burn risk assessments at combustion facilities as national policy through its combustion strategy, and many state regulatory agencies are following this strategy. Under these amendments, a two phase process to implement such a strategy has been codified. Phase I is a pre-trial burn multi-pathway health risk assessment (MPHRA), conducted on the estimated emissions from the facility operation. Air dispersion modeling must be conducted by the applicant to estimate the ambient concentrations of hazardous constituents due to facility emissions. This phase projects whether emissions from the facility operation as proposed would exceed health risk based levels in the ambient environment, and identifies the location of highest estimated concentrations. Phase I serves as a screening tool to identify whether risk based performance standards of Part 264-Subpart O are met based on design estimates of emissions, using conservative screening protocols, and identifies where site specific air dispersion modeling and risk assessment procedures are needed. Alternatively, the facility could conduct a thorough site specific risk assessment in Phase I using the best emissions estimates available.

The second phase is a site specific post-trial burn MPHRA conducted on the measured emissions from the facility after permitting and construction, during interim operations. Phase II utilizes measured emissions from the facility operation obtained during the trial burn to assess whether health risk based performance standards will be exceeded in the ambient environment. Both Phase I and II require that the applicant utilize air dispersion models approved by the Department, and a risk assessment methodology subject to the Department's approval as part of the application. Both phases include an assessment of both direct inhalation and indirect health risk through deposition of constituents in the environment and uptake through media, such as surface water, and through ingestion of locally grown plant and animal matter. The exposure scenarios and toxicological data consider sensitive subpopulations such as children in the risk assessment process.

The risk assessment methodology in these amendments requires summation of carcinogenic risk across all major exposure pathways, for all identified compounds, resulting in a cumulative risk from operation of the hazardous waste incineration facility. (In contrast, the procedure in the BIF rule handled carcinogenic risk from metals and dioxins and furans separately.) In addition, a target risk level of one in a million (1 E-6) added lifetime cancer risk (ALCR), also referred to as "increased lifetime cancer risk", has been established for the hypothetical "most exposed individual" (MEI) due to facility emissions. In contrast, the federal BIF rule uses 1 in 100,000 (1 E-5), a target risk level which the Department does not currently accept as an initial target level for protection of human health as a policy matter in its Hazardous Waste Control Program. This revision is otherwise consistent with the combustion strategy, and reflects current practice of EPA and many states conducting risk assessments at hazardous waste combustion facilities.

The MEI is the hypothetical person at a site determined through air dispersion modelling as the location of highest average ground level ambient concentration of the constituents of concern, and therefore the location of high-end potential individual health risk, regardless of whether anyone lives or works at this location. The dispersion modelling identifies whether the MEI is located on-site or off-site, which in turn affects the exposure scenario(s) and risk management alternatives. This combination of estimated exposure levels and location may also be referred to as the location of "reasonable maximum exposure" (RME).

The Commission recognizes that risk assessment and management is an evolving science as well as a policy matter. These amendments require that facilities utilize risk assessment methodology and procedures approved by the Department. If advances in the science or site specific considerations dictate changes to the assessment procedures, these must be implemented and documented in the administrative record for a permit decision. For a given site, there may be a spectrum of ways to conduct a risk assessment for a situation as complicated as a HWI facility, some being more comprehensive than others. Available published guidance documents may be utilized as necessary to determine the most appropriate methodology and protocols for conducting risk assessments. For example, the documents "Revised Draft of Risk Assessment Implementation Guidance for Hazardous Waste Combustion Facilities" (EPA, OSW, April 22, 1994, and referred to as the Implementation Guidance), "Methodology for Assessing Health Risks Associated with Indirect Exposure to Combustor Emissions" (EPA/600/6-90/003; ORD 1990 and referred to as the Indirect Exposure Document), and the "Draft Addendum" (EPA 1993) to that document, provide valuable information in preparation of indirect risk assessments. It is recommended that the applicant work closely with the Department in designing the Phase I and II risk assessments.

There may be cases where ecological receptors are more sensitive than humans. If the information obtained during the Phase I and II MPHRAs indicates that an evaluation of risk to ecological receptors is needed, or would be beneficial in determining appropriate and environmentally protective permit conditions, the Director may require the applicant/permittee (as appropriate) to perform an ecological risk assessment. An ecological risk assessment, if required, will be conducted in accordance with procedures and methodologies approved by the Director to ensure protection of human health and the environment.

(2) REVISION: Comparison of measured rates of emissions of Appendix VIII compounds to performance standards (e.g., RACs and RSDs) in estimated emissions and trial burn results (§ 100.22(c)(7)). These amendments require that facilities which submit an application to operate a HWI facility perform a comparison of estimated (pre-trial burn) and measured (post-trial burn) emissions with the published Reference Air Concentration (RACs) and Risk Specific Dose (RSDs) for each compound.

BASIS: References # 1, 4, 6.

DISCUSSION: These amendments have been added for several technical reasons:

(a) to evaluate if health-risk based levels of Appendix VIII compounds are exceeded in the ambient air for a hypothetical high end exposure scenario (similar to worst case MEI);
(b) to determine if a facility may pursue interim operations during preparation and evaluation of a site specific risk assessment; and
(c) to serve as a check on the risk assessment results. Under the existing Subpart O regulations and the federal BIF rule, facilities are not specifically required to perform a comparison of ambient levels of organic compounds detected in the stack emissions during the trial burn with the RACs and RSDs of Appendix IV and V to determine if health based emissions levels have been exceeded for these compounds. Conformance with the destruction and remove efficiency (DRE) standard for POHCs is the only explicit standard for organic compounds. These amendments provide an additional level of specificity and protection not contained in existing Subpart O or the federal BIF rule, and provides a more enforceable method to evaluate compliance with performance standards. A more detailed discussion on specific performance standards is provided later in this document addressing amendments to Part 264-Subpart O.
(3) REVISION: Notification of intent to submit a Part B permit application (§ 100.41(b)(5)): These amendments add a requirement that the facility publish a notification in a major local newspaper which identifies that an application will be submitted for a HWI facility. Criteria for the notification is specified in the amendments.

BASIS: References # 4, 12

DISCUSSION: Based on testimony provided to the Commission, public participation and community involvement were identified as key elements in an effective approach to managing HWI and combustion projects. EPA policy clearly points to public participation as an important aspect of the combustion strategy. These amendments require that the applicant of a proposed HWI facility notify the community that a permit application will be submitted to the Department. In the past, the Department has issued a press release and handled inquiries regarding an application upon submittal. Requiring the facility to initiate the notification would ensure timely notification of the public, and would place more responsibility on the applicant for handling community involvement issues.

(4) REVISION: Notification of Receipt of a permit application and opening of public comment period on an application § 100.506): These amendments require that the Department publish a notification of submission of an application in a major local newspaper, and requires the Department to open a public comment period during the application stage, prior to the Department's final approval of the trial burn plan and prior to issuance of a notice of completeness or a draft permit. A requirement to establish an information repository has been added in order to ensure that all major documents relevant to the project are available for review near the local community.

BASIS: References # 4, 14.

DISCUSSION: Under the Colorado hazardous waste regulations and federal RCRA regulations, the only formal public comment period is held upon issuance of a draft permit decision by the Department. Although nothing prevents any member of the public from commenting on a pending application, the Department's experience is that it is rarely done. In fact, the Department appreciates any relevant information that can be provided prior to the preparation of a draft permit decision. These amendments explicitly require the Director to solicit comments on the application prior to the issuance of a notice of completeness on the application or the formal comment period on a draft permitting decision. In particular, the Department encourages comments on the trial burn plan and Phase I risk assessment prior to final approval, as these are key documents related to the operation of the proposed facility. These amendments also require that the Department publish a notice at the time that the trial burn plan has been approved and dates for conducting the trial burn. Additional public participation will be handled under a community involvement plan (see amendment # 5 of this section), and will include informational meetings focused on particular issues related to the application under review. Addition of the application phase comment period results in the following three distinct comment periods:

1. Application stage, including trial burn and Phase I risk assessment (New requirement.)
2. Draft permit issuance (or denial) stage. (Existing requirement.)
3. Final permit modification stage, to incorporate trial burn results and Phase II risk assessment information. (Revision to existing requirement; see also revision # 6.)

Nothing prevents the Department from extending a comment period or holding additional comment periods during the permitting process for a treatment, storage, or disposal facility. These amendments do not affect existing procedures for appeal of the Department's final permit decisions under § 100.514.

(5) REVISION: Development of a Community Involvement Plan (§ 100.41(b)(5)): These amendments require that facilities which have submitted an application for a HWI permit develop a Community Involvement Plan (CIP) and include it with the application for the Department's review and approval.

BASIS: References # 4, 12, 14.

DISCUSSION: The purposes of the CIP are:

(a) to ensure that the local community is informed regarding technical and regulatory matters related to the proposed HWI facility,
(b) ensure that a mechanism is in place for the community to obtain information related to the proposed facility, and
(c) provide a forum for the community to voice their comments and concerns to the facility and regulatory agencies as these concerns arise. This approach places more responsibility on the owner/operator of the proposed facility to handle public participation, but also is intended to increase access to the Department and local governmental authorities. Guidance for development of a CIP is available, including the "RCRA Public Involvement Manual' (EPA/530-R-93-006).
(6) REVISION: Final permit modification stage to incorporate trial burn results and Phase II risk assessment information (§ 100.63-Appendix I): These amendments revise the classification of final permit modifications to incorporate trial burn results and establish final operating conditions.

BASIS: References # 4, 12, 14.

DISCUSSION: These amendments revise the classification of final permit modifications to incorporate trial burn results and establish final operating conditions so that all modifications are either Class 2 or Class 3, rather than retain a category for Class 1 modifications with prior approval. The purpose of this amendment is to ensure that there is a public comment period for all modifications of hazardous waste incinerator permits at the time the permit is finalized to incorporate trial burn and Phase II risk assessment results, and a Class 1 with prior approval does not require a comment period. Reorganization of this section has been done to be consistent with EPA's June 2, 1994 proposed regulations for enhanced public participation, but no other substantive changes were made.

(7) REVISION: Addition of disclosure requirements for a permit to operate a hazardous waste incineration facility (§ 100.40(b)): These amendments provide explicit requirements for disclosure of past compliance history by an applicant(s) for a permit to operate a hazardous waste incineration facility.

BASIS: References # 2, 5, 14, 15.

DISCUSSION: Under existing regulations, applicants for a hazardous waste treatment storage or disposal facility permit are not required to provide a disclosure to the Department regarding their past environmental compliance history. These amendments provide explicit requirements for disclosure of past compliance history by an applicant(s) for a permit to operate a hazardous waste incineration faculty. The compliance history is important information for both the Department and the public in evaluating an applicant's commitment and ability to manage an incineration facility safely and in accordance with all applicable environmental regulations to ensure protection of human health and the environment. The Commission also identified a need for legislative action to clarify the Department's authority to consider an applicant's compliance history in a permit decision.

(8) REVISION: Minor amendments to ensure that § § 100.22 and 100.41 are consistent with the revisions to Part 264, such as revised citations, formatting, and overall organization of these sections.

BASIS: These amendments ensure consistency between amendments to Part 100 and Part 264.

THE FOLLOWING REVISIONS ARE INCORPORATED INTO 6 CCR 1007-3. PART 264- SUBPART O:

(9) REVISION: Part 264-Subpart O Performance Standards (§ 264.342): These amendments contain a two level approach to establishing Part 264-Subpart O performance standards for emissions from an incinerator burning hazardous waste:

LEVEL I. A human health, risk based, target level that cannot be exceeded based on a full Multi-Pathway Health Risk Assessment (MPHRA) which considers both direct and indirect exposure pathways for the full suite of compounds examined during the approved trial burn. The MPHRA is subject to review and approval by the Department. The acceptable performance standard for the MPHRA is an ALCR target level of 1 E-6 (1 x 10-6), and a hazard index (or quotient, as appropriate) of < 0.25 for noncarcinogens. (See also the discussion of the Phase II risk assessment requirements under revision #1 to Part 100.)

LEVEL II: A human health, risk based performance standard that cannot be exceeded at anytime as a result of the emissions from the permitted hazardous waste incinerator. Level II performance standards are used during the operational period as a tool to assess whether levels of stack emissions of specified metals and organic compounds exceed the health based standards of Tables IV and V of this Subpart. Periodic compliance stack testing, including those tests required under amended § 264.347(e), is utilized to make this assessment.

BASIS: References # 1, 4, 9, 14.

DISCUSSION: These amendments establish performance standards and a two level approach to evaluating compliance with the performance standards of Subpart O. During the facility's permit application process, and prior to a final decision on permit issuance, the facility will be required to perform two MPHRAs under these amendments. The first (Phase I pre-trial bun) MPHRA is performed on the design (estimated) emissions from the facility to determine if a unacceptable human health risk exists, and establish whether or not to proceed with a permit. If a draft permit is prepared, the information is utilized by the Department to determine applicable permit conditions for the facility. The second (Phase II) MPHRA is performed using the actual measured (trial burn) emissions data from the facility to determine whether the calculated health risk from the facility meets the performance standards established in Level I. If those performance standards are met, this information will be used to establish final permit conditions for the facility.

The Phase II (post-trial burn) MPHRA establishes a conservative, estimated, overall high end individual risk from exposure to emissions from the incineration device, and is best performed in conjunction with a trial burn. It does not provide a straightforward quantitative measure of compliance during the operational period. Performing a MPHRA is both complicated and potentially costly, and it is likely to be a cumbersome procedure for conducting periodic compliance tests when applied to normal operating conditions. Using the MPHRA as a compliance test would best be done concurrently with a repeated trial burn. For Level I, the established target risk level is a 1 E-6 upper-end ALCR, and a hazard index (or quotient, as appropriate) of < 0.25 for noncarcinogens. This ALCR target level is currently used by the Department for its CHWA regulatory programs in assessing high-end human health estimates of risk from environmental exposures. Use of a hazard index of 0.25 is designed to account for background exposure to the same or other compounds with the same health effects from other sources.

These amendments establish compound specific numerical performance standards (Level II) for the compounds listed in Appendices IV and V of the BIF Rule against which to compare the emissions from the HWI facility. These are quantitative ambient air standards which must be met by the stack emissions under approved operating conditions. The Level II standards are linked to health based inhalation standards promulgated by EPA in the BIF Rule, published in Appendices IV and V of the BIF Rule as the Reference Air Concentration (RAC) and the Risk Specific Dose (RSD), respectively, and are at least as protective. For carcinogenic compounds, these amendments establish a more conservative target level for the ALCR of 1 E-6 (as opposed to 1 E-5), implemented by dividing each RSD in the BIF rule by 10. Level II assesses only direct inhalation risk, but requires a consideration of the relative contribution of each exposure pathway to the risk which was calculated under Phase II. Lowering the target risk level, and taking into consideration the relative percentage contribution of each major exposure pathway, compensates for the indirect portion of the potential risk not taken into account using only a direct inhalation pathway, and is consistent with target risk levels utilized in the Department's hazardous waste control program for protection of human health and the environment.

These amendments set an acceptable target level of 1 E-6 for each carcinogen, which is ten times more conservative than the RSD values in the BIF rule (i.e., RSD/10). The RACs have not been revised, as they are conservatively based on 25% of the Reference Dose (RfD) (see BIF rule preamble discussion, Feb. 21, 1991). A more detailed discussion of specific standards for each category of compounds (i.e., metals, particulate matter, hydrogen chloride gas and chlorine, and organic compounds) is provided elsewhere in this Statement of Basis.

The Commission concluded that trial burn data is designed to represent extremes of normal operating conditions, and does not reflect operation at upset conditions. Using a conservative ALCR target for the Level II standards is considered a valid approach to estimate the high end direct inhalation risk without performing a MPHRA for routine compliance activities.

Compliance with the numerical standards established in the BIF rule was determined by the Commission to provide sufficiently conservative and protective standards, and is a more useful and enforceable method for assessing routine compliance than reliance upon a MPHRA. As health based standards are revised, or additional standards developed, the Commission will promulgate appropriate revisions to these regulations. These amendments establish that non-compliance with Level II performance standards would be a violation of the facility's permit, and would be information which would be assessed by the Department in determining whether a Level I MPHRA would be required during the operational period.

Under the BIF rule, the allowable ALCR for metals is 1 E-5, and organic products of incomplete combustion (PICs) are not factored into the risk equation if DRE is met, except that risk from polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) is calculated for facilities utilizing certain air pollution control devices. PCDD/F risk is then added at a 1 E-5 ALCR level, resulting in total allowable risk under the BIF rule of 2 E-5. The published RSDs (and RACs) for other compounds are applied only to the low risk waste exemption under 40 CFR 266.109, and are therefore not required to be examined for all cases. Therefore, these amendments result in a more stringent regulation for incineration facilities than the BIF Rule or existing Subpart O regulations.

For Level II, these amendments require a summation of ALCR from metals, PCDD and organic PICs, (i.e., ALCRtotal = ALCRmetals + ALCRpcdd/f + ALCRpic) based on a comparison of emissions (estimated and actual) with the RSD (see Equations in § 264.342). The performance standard for this comparison is ALCR [LESS THAN EQUAL TO] 1 E-6. This standard is more conservative than that under the BIF rule (i.e., 1 E-5).

(10) REVISION: Particulate matter standard (§ 264.343). These amendments revise the particulate matter (PM) standard from 0.08 to 0.010 grains per dry standard cubic foot (gr/dscf) in the stack emissions from a HWI facility.

BASIS: References # 4, 5, 6, 10, 13, 14.

DISCUSSION: These amendments establish a PM standard of 0.010 grains per dry standard cubic foot (gr/dscf) (23 mg/dscm) in the emissions from all units subject to these revised Subpart O standards. This limit replaces the standard of 0.08 gr/dscf found in both Part 264- Subpart O, and in the federal BIF rule. Information presented to the Commission by the Department, the Sierra Club, and that located in EPA documents, indicates that the existing 0.08 standard is not representative of best operating practice (BOP) or maximum achievable control technology (MACT) for hazardous waste incinerators. Based on EPA documents, the 0.010 standard represents good combustion practice, is consistent with the CETRED BOP values and the proposed federal new source performance standard (NSPS) for municipal waste combustors.

Control of PM in emissions from combustion devices is considered an essential aspect in control of certain metals, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and other semi-volatile organic compounds. This amended PM standard will require owners and operators of Subpart O units to use the emissions control technology necessary to effectively limit participate emissions and the inorganic and organic compounds associated with these emissions.

(11) REVISION: Total Hydrocarbon standard (§ 264.342(d)): These amendments establish a total unburned hydrocarbon (HC) standard of 20 parts per million volume (ppmv) basis. Continuous monitoring of HC in stack emissions is required.

BASIS: References # 1, 4, 5, 6.

DISCUSSION: These amendments establish a total hydrocarbon (HC) standard to ensure that all Subpart O units operate under conditions indicative of efficient combustion. An HC standard and continuous emissions monitoring is to be used in addition to the carbon monoxide standard of 100 ppm, to provide a second indicator of combustion efficiency. In the BIF rule, HC monitoring is implemented with an alternative CO standard in the BIF Rule, and would be set in the final permit based on the results of the trial burn. No alternate HC standard is proposed based on characteristics of the feed to the unit, as in the BIF rule.

The Commission has determined that a 100 ppm CO standard in combination with a HC standard and monitoring represents more effective control of organic emissions which might otherwise pass undetected into the atmosphere. The utility of HC limits is discussed in the preamble to the BIF rule (Feb. 21, 1991), and a 20 ppm limit is considered representative of good combustion conditions. Good combustion conditions are also correlated with low emissions of PICs.

The HC monitoring proposed is not compound specific, rather the requirement is added to monitor and control those parameters which will be used to achieve the performance standard for POHCs and other organic compounds, and minimize formation of PICs.

(12) REVISION: Carbon Monoxide (CO) standard (§ 264.342(c)): These amendments establish a CO standard of 100 ppmv, applicable to the emissions from all Subpart O units.

BASIS: References# 1, 4.

DISCUSSION: Under existing Subpart O regulations, the CO limit was established during the trial burn. These amendments establish a CO standard of 100 ppmv, applicable to the emissions from all Subpart O units. Although the Commission agreed that CO is not conclusively correlated to DRE, CO is indicative of efficient combustion conditions and CO is a PIC. Since results of trial burns show that the DRE is routinely met when CO is below 100 ppm, this standard has been implemented in a number of incinerator permits nationwide by state agencies and EPA. No alternative (higher) CO limit is allowed under these amendments as it is in the BIF rule.

(13) REVISION: Metals emissions standards (§ 264.344): These amendments establish metals feed rate and emissions standards for hazardous waste incineration facilities.

BASIS: References # 1, 4, 5, 6.

DISCUSSION: These amendments incorporate metals emissions standards (and feed rate limitations) developed under the federal BIF rule. Values for acceptable ambient levels of carcinogenic compounds, (i.e., the risk specific dose (RSD) in Appendix V of the BIF rule) have been lowered by a factor of ten to provide a more conservative limit corresponding to a added lifetime cancer risk to the MEI of one in a million (1E -6). The values for acceptable ambient levels of non-carcinogenic compounds (i.e. reference air concentrations (RACs)) were not modified as they are based on 25% of the reference dose (RfD), which considers threshold health effects. These limits are health based standards and therefore provide an additional level of protection over the existing Subpart O regulations.

(14) REVISION: Hydrochloric acid/chlorine gas standard (§ 264.345): These amendments incorporate the emissions standards for hydrochloric acid gas and chlorine developed under the federal BIF rule into these revised Subpart O regulations.

BASIS: References # 1, 4, 5.

DISCUSSION: These amendments incorporate the emissions standards for hydrochloric acid gas and chlorine developed under the federal BIF rule into these revised Subpart O regulations, a change which is consistent with EPA's national policy.

(15) REVISION: Controls for dioxins and furans (§ 264.342(e)): These amendments establish an emissions standard of 13 nanograms per dry standard cubic meter of gas (ng/dscm) total congeners, and 0.17 ng/dscm toxicity equivalency (TEQ) for dioxins and furans. These amendments specify that the Director may set a lower standard in a permit if these values are not protective based on the Phase I or Phase II MPHRA.

BASIS: References # 4, 10, 13.

DISCUSSION: These amendments establish an emissions limit of 13 ng/dscm (based on the sum of all tetra through octa dioxin and furan congeners) for the TCDD (tetra-CDD) equivalents, and a 0.17 ng/dscm TEQ of 2, 3, 7, 8-tetrachlorinated dibenzo-p-dioxin (NATO 1989 international criteria). A requirement is included that PCDDs/Fs be sampled and analyzed for in any trial burns for Subpart O units. The BIF rule addresses only those combustion devices using certain types of air pollution control devices. A similar requirement is being implemented under the combustion strategy. A great deal of controversy and uncertainty surrounds PCDDs/Fs as products of incomplete combustion or their reformation in exhaust gas from HWI facilities and other combustion devices. An initial PCDD/Fs stack test during the trial burn provides a baseline demonstration of the emissions rate of these compounds, and allows a determination whether target health risk levels (i.e., Level I or Level II performance standards) are exceeded by the emissions levels.

Alternative stack gas emissions limits (i.e., if 13 ng/dscm and 0.17 ng/dscm TEQ is not protective based on the risk assessment), and ongoing requirements for emissions monitoring will be based on the levels demonstrated during the trial burn. Without these data, no basis will exist for determining if PCDD/Fs emissions are present at levels which pose a health risk. Further, no state air emission limit currently exists for these compounds from hazardous waste incineration or combustion devices, so stack testing for PCDD/Fs is not likely to be required under an air emissions permit at this time. A document entitled "Combustion Emissions Technical Resource Document", EPA530-R-94-014, June 1994, performed calculations to generate BOP levels, using a MACT-type analysis, and this information supports use of a specific emissions standard very close to the one adopted in these amendments. EPA has published proposed revisions to the NSPS for municipal waste combustors which supports a total dioxin standard of 13 ng/dscm.

(16) REVISION: For all Appendix VIII organic compounds: These amendments incorporate language into § § 264.342 and 100.22(c) to explicitly require:
(a) facilities report results of all compounds sampled and analyzed during the trial burn, not just POHCs, including PICs identified in the analysis of stack gas;
(b) facilities calculate maximum ambient air concentrations with an approved dispersion model using measured values from the trial burn stack test; and
(c) facilities perform a comparison of calculated values from item (b) with health based values of RACs and RSDs from 40 CFR Part 266 appendices IV and V.

BASIS: References # 1, 4, 9, 14.

DISCUSSION: Under existing Subpart O and the federal BIF rule, facilities are not required to perform a comparison of levels of organic compounds detected in the stack emissions during the trial burn with the RACs and RSDs of Appendix IV and V to determine if health based emissions levels have been exceeded for these compounds. Conformance with the DRE standard for POHCs is the only standard for organic compounds. These amendments provide an additional level of specificity and protection not contained in the federal BIF rule. The procedure could also be used to back-calculate compound specific emissions limits. This requirement will not place any significant financial burden on the facility performing the stack test, as the emissions sampling and analyses will have already been performed under the analytical methods required for DRE determination for the POHCs. The facility must then use the measured levels of organic compounds in a conservative or site specific emissions dispersion model to determine maximum ambient air concentration levels. This effort will quantify those PICs which are identified by the specific analytical method used, such as volatile organic compounds using method 8240 (or equivalent).

(17) REVISION: Periodic sampling and analyses of environmental media (air, soil, surface water) in proximity to the incineration facility (§ 264.347(d)): These amendments provide the explicit authority to the Department to require ambient monitoring of environmental media in a facility's permit, or prior to receiving a final operating permit, under certain circumstances.

BASIS: References # 2, 5, 6, 14.

DISCUSSION: Under these amendments, if the results of the air dispersion modeling and risk assessments conducted under revised § 100.22(c), or other information obtained by the Director, indicate that ambient levels of Appendix VIII constituents may pose a risk to human health or the environment (by exceeding performance standards), the Director will require the Permittee to sample environmental media and analyze it for the constituents of concern. An example would be emissions of metals which could accumulate in soils at some distance from the facility's stack if these were identified at significant levels in the stack emissions.

This requirement could include initial sampling conducted prior to operation of a hazardous waste incinerator, which would be used to establish baseline levels of the constituents of concern at selected locations. This background information is necessary in order to make comparisons before and after the facility goes into operation. Locations of sampling would be based upon the air dispersion modeling results, and an assessment of the surrounding area, including land use patterns. Periodic monitoring of the media of concern for these compounds would be required in the facility's operating permit to provide for comparison with the baseline levels of the constituents of concern. This determination would be based on information available to indicate whether a potential for significant deposition and accumulation exists for the compounds of concern.

If sampling of environmental media is required, these amendments require a Permittee to develop a sampling and analysis plan for the Director's review and approval. Following the Director's approval of the sampling and analysis plan and its subsequent implementation, the Permittee would prepare a report containing the results of such sampling and analyses to the Director. The Director would review the results and provide comments to the Permittee. Based on these results, the Director may require the Permittee to perform revised and/or additional site specific risk assessments. If the results of sampling of any environmental media indicate that levels of any Appendix VIII constituents released as a result of hazardous waste incineration activities may pose a risk to human health or the environment, these amendments specify that the Director would modify, revoke and reissue, or terminate the State RCRA permit for the incineration facility.

The Commission recognizes that a number of uncertainties exist in designing and performing ambient monitoring of air, soil, water or vegetation, as well as interpreting the results obtained. In addition, is likely to be an economically significant effort. The benefits, costs, and uncertainties would need to be examined in making site specific decisions regarding such a requirement. The Commission determined that implementation of such a requirement will aid in addressing both technical issues and certain citizen concerns, such as contamination of food crops and local ambient air quality issues as a result of the incineration activity. It would also provide data with which to evaluate and compare risk assessment estimates.

(18) REVISION: Periodic stack emissions test (§ 264347(e)): These amendments clarify the Department's authority to incorporate a periodic stack emissions sampling and analysis frequency in an incineration facility's operating permit.

BASIS: References # 5, 6, 14.

DISCUSSION: Under the current Subpart O regulations (§ 264.347(a)(3)), the Department had the authority to require the Permittee to conduct sampling and analysis, and report the results. However, the Commission considered the requirement too vague as a basis for establishing permit conditions. These amendments clarify the authority to explicitly require periodic testing in accordance with procedures specified in the facility's permit to demonstrate compliance with applicable performance standards. This testing may be similar to a repeat of the trial burn, or may examine only certain compounds of concern. It is not intended that the Department would require DRE to be calculated at each sampling event. However, the facility may be required to reaffirm compliance with the DRE standard during the operational life of the permit, particularly if information indicates that this performance standard is not being met These amendments also require that a report containing the results of the periodic stack test would be prepared in accordance with the permit, generally within 90 days of completion of the testing.

(19) REVISION: Compound specific emissions monitoring (§ 264.347(f)): These amendments explicitly provide the authority to the Department to incorporate compound specific emissions monitoring requirements into the facility's operating permit.

BASIS: Clarification of existing regulations, References # 6, 14.

DISCUSSION: These amendments clarify the Department's authority to address compound specific emissions monitoring in the facility's operating permit for those compounds that are of major concern, and the technology exists to monitor these compounds. These amendments require the Permittee to assess the available technology for monitoring the required emissions. If the Permittee cannot locate commercially available technology that meets the requirements for monitoring required by the Director, the Permittee would be required to submit a certified statement to the Director explaining the facility's efforts to meet the requirement. Currently, continuous emissions monitors (CEMs) are available for O2, CO, HC, CO2, HCl, SOx, NOx, opacity, certain chemical warfare agents (e.g., mustard), but not for a wide variety of organic compounds (i.e., PICs) which may be present at low levels in the stack emissions. However, industry and academic organizations are working on development of commercially available monitoring devices for organic and metallic compounds. The appropriate devices would be specified in an operating permit, once commercially available.

(20) REVISION: Remote data acquisition for continuously monitored operating conditions and emissions (§264.347(g)): These amendments require the Permittee to provide a system to the Department for remote data acquisition of periodically or continuously monitored operating conditions and emissions.

BASIS: References # 5, 6, 14.

DISCUSSION: Remote monitoring generally consists of real-time electronic data transfer from an operating facility to the regulatory agency(s). These amendments require that the general performance characteristics of a remote monitoring system would be proposed in the facility's permit application, or specified by the Director in an operating permit, to improve real time monitoring of facility emissions and assess compliance with permit standards. The system would be used by the Director to monitor the operating conditions and the periodically and continuously monitored emissions of the incineration facility. For example, such a system is in use for the RMA-SQ1. The system would typically be located at the Department's office, but the technology exists to place a monitor at other locations, such as a local health department

(21) REVISION: Additional personnel training requirements (§ 264.347(h)): These amendments add personnel training requirements specific to operators of hazardous waste incineration faculties and provide a more explicit set of requirements for incineration facilities than contained in § 264.16.

BASIS: References # 13, 14.

DISCUSSION: Under existing regulations, owners and operators of all hazardous waste treatment storage or disposal faculties are required to develop a personnel training plan as part of the facility's permit application. These amendments expand on the existing requirements by adding language specific to training for operators and maintenance personnel at incineration facilities. In particular, operators will be required to complete a training program to ensure that they are qualified to operate an incineration facility or certain aspects of one for which the operator is responsible. Maintenance personnel must be trained in their area of responsibility, and all personnel must receive training in contingency plan and emergency response procedures. The Commission also identified a need for legislative action to clarify the Department's authority to require operators of hazardous waste incineration facilities to complete a certification program to demonstrate their qualifications, similar to that required by EPA for operators of municipal waste combustors or publicly owned treatment works.

(22) REVISION: Additional requirements for contingency plans at hazardous waste incineration facilities § 264.347(i)): These amendments provide a more explicit set of contingency plan and emergency response requirements for incineration facilities than contained in Part 264-Subparts C and D.

BASIS: Reference # 14.

DISCUSSION: Under existing regulations, owners and operators of all hazardous waste treatment storage or disposal facilities are required to develop plans and procedures to prepare for, prevent, and respond to emergencies involving waste management operations as part of the facility's permit application. These amendments expand on the existing requirements by adding language specific to owners and operators of incineration facilities. In particular, these amendments require development of more sophisticated evaluation procedures for emergencies and accident involving hazardous waste, and place more responsibility on the owner or operator to coordinate off-site emergency response efforts with the local emergency response authorities.

Final Note: An applicant should be aware that the owner or operator of a proposed hazardous waste incineration facility is required to obtain a certificate of designation under 25-15-Part 5 C.R.S., for a facility applying for a permit to burn hazardous waste under the requirements of 6 CCR 1007-3, Part 264-Subpart O.

Statement of Basis and Purpose - Rule-making Hearing of August 22, 1995

Notes

6 CCR 1007-3-8.18
37 CR 24, December 25, 2014, effective 3/2/2015 38 CR 11, June 10, 2015, effective 6/30/2015 39 CR 05, March 10, 2016, effective 3/30/2016 39 CR 11, June 10, 2016, effective 6/30/2016 40 CR 06, March 25, 2017, effective 4/14/2017 40 CR 11, June 10, 2017, effective 6/30/2017 40 CR 21, November 10, 2017, effective 11/30/2017 41 CR 06, March 25, 2018, effective 4/14/2018 41 CR 11, June 10, 2018, effective 6/30/2018 41 CR 24, December 25, 2018, effective 1/14/2019 42 CR 06, March 25, 2019, effective 4/14/2019 42 CR 06, March 25, 2019, effective 5/30/2019 42 CR 11, June 10, 2019, effective 6/30/2019 43 CR 12, June 25, 2020, effective 7/15/2020 44 CR 06, March 25, 2021, effective 4/14/2021 44 CR 11, June 10, 2021, effective 6/30/2021 44 CR 24, December 25, 2021, effective 1/14/2022 45 CR 11, June 10, 2022, effective 6/30/2022 45 CR 17, September 10, 2022, effective 9/10/2022 45 CR 17, September 10, 2022, effective 9/30/2022 45 CR 23, December 10, 2022, effective 1/30/2023

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