6 Colo. Code Regs. § 1007-2-9

Current through Register Vol. 47, No. 11, June 10, 2024

Section 6 CCR 1007-2-9 - WASTE IMPOUNDMENTS

9.1.GENERAL PROVISIONS

9.1.1.SCOPE AND APPLICABILITY:This Section 9 applies to all waste impoundments, as defined in Section 1.2 of these Solid Waste Regulations, where storage, treatment, utilization, processing, or deposit and final treatment of solid waste occurs, unless exempted in Section 9.1.2 below.

Sections 1 and 2 of these Solid Waste Regulations are applicable to all waste impoundments and ancillary equipment associated with a waste impoundment, unless specifically otherwise noted herein. Sections 1 and 2 of these Solid Waste Regulations do not apply to the impoundments exempted in Section 9.1.2(A)(1), (3), (4), (6), (7), (8), (10), (11), (13), (14), (15), (16) and (17). For ease of use, this Section 9 includes those Section 2 requirements that usually apply to the operation of waste impoundments; however, there may be unique features at a particular facility that trigger additional site-specific Section 2 requirements not referenced in this Section 9.

Facilities subject to this Section 9 must obtain a certificate of designation (CD) unless otherwise exempt per Section 30-20-102, C.R.S., or these Regulations. The CD will include, at a minimum, the engineering, design and operations plan (EDOP) for the facility required by this Section 9. Facilities that require a CD must follow the CD application process in Section 30-20-103, C.R.S., and these Regulations. See section 1.6 of these Solid Waste Regulations.

Facilities subject to this Section 9, but exempt from the requirement to obtain a CD, must provide an EDOP to the Department for review and approval prior to implementation. Nothing in this section shall preclude any review action that may be required by the local governing authority under appropriate local ordinance or rule. See sections 1.3.9 and 1.4.1 of these Solid Waste Regulations.

Section 30-20-100.5(1)(a), C.R.S. provides that proper disposal of solid wastes is a matter of mixed statewide and local concern. Because a facility may also need to comply with applicable local requirements in addition to this Section 9, facilities should check with the local governing authority for their submittal, notification, and approval requirements. The phrase "Department and local governing authority approval, as appropriate," as used in this Section 9 acknowledges that the Solid Waste Act and Regulations establish dual jurisdiction over solid waste. Facilities should review Title 30, Article 20, Part 1, C.R.S., and the Solid Waste Regulations to determine which authorities apply.

Compliance with this Section 9 shall not relieve the facility owner or operator from the obligation to comply with the facility's CD and any other applicable federal, state or local statute, regulation, requirement or ordinance.

9.1.2.EXEMPTIONS

(A) This Section 9 does not apply to the following:

(1) Impoundments whose design and primary function is retaining or detaining stormwater for water quality or flood control purposes as required by any state, district, or local requirement;

(2) Stormwater/leachate impoundments subject to the composting regulations under Section 14 of these Solid Waste Regulations;

(3) Raw water impoundments;

(4) Secondary containment;

(5) Tanks incorporating structural and water-retaining elements into their design and construction (exemption includes basins constructed of reinforced concrete and whose joints are sealed with water and joint sealant and whose sidewalls may be either sloped or vertical so long as reinforced);

(6) Impoundments that contain water in a treatment process and whose primary function is water treatment, not waste treatment or disposal (exemption includes drinking water treatment backwash ponds that recycle water for further treatment, even if those ponds are periodically taken out of service for solids handling and removal);

(7) Impoundments that do not contain solid waste, as defined in Colorado Revised Statutes (CRS) 30-20-101;

(8) Impoundments containing only substances exempted from the definition of Solid Waste by section 30-20-101(6)(b)(l) through (VIII), C.R.S.;

(9) Impoundments subject to a consent order, decree or agreement or a written cooperative agreement issued pursuant to the "Solid Waste Disposal Sites and Facilities Act", CRS, 30-20-101, et seq., as amended, to the extent that the treatment, storage or disposal of such wastes in a waste impoundment is approved by the Department pursuant to such consent order, decree, agreement, or written cooperative agreement;

(10) Impoundments subject to license issued pursuant to the "Radiation Control Act", CRS 1973, 25-11-101, etseq., as amended;

(11) Impoundments subject to an uncontested order, a consent order, decree or agreement; or a written cooperative agreement issued pursuant to the federal "Comprehensive Environmental Response Compensation and Liability Act of 1980", as amended, to which the Department is a signatory party, to the extent that the treatment, storage or disposal of such wastes in a waste impoundment is approved by the Department pursuant to such uncontested order, consent order, decree, agreement, or written cooperative agreement;

(12) Impoundments subject to the commercial exploration and production (EP) waste impoundment regulations under Section 17 of these Solid Waste Regulations;

(13) Impoundments subject to the requirements for oil and gas liquid waste impoundments regulated by the Oil and Gas Conservation Commission;

(14) Ponds and basins operating under the Water Quality Control Commission (WQCC) Regulation 64;

(15) Impoundments which are used for temporary or emergency (up to 30 days) storage of solid waste (this temporary storage time-frame must be documented to ensure the 30-day time frame is not exceeded);

(16) Impoundments operating under WQCC Regulation 84;

(17) Impoundments that are subject to a permit issued pursuant to the Colorado Mined Land Reclamation Act, section 34-32-101 and the Colorado Surface Coal Mining Reclamation Act, section 34-33-101, CRS, et seq.

(18) Other waste impoundments exempted, based on a case-by-case determination, by the Department.

(B)Reserved

9.1.3.PRECLASSIFICATION:

(A) The following types of impoundments are preclassified as Type A:

(1) Coagulant sludge impoundments at surface water treatment plants;

(2) Reserved.

The impoundment types that are preclassified as Type A are not subject to Sections 9.1.7, 9.1.8, 9.1.9, and 9.3. The impoundment types preclassified as Type A are subject to Section 9.2.

9.1.4EFFECTIVE DATE: This Section 9 was adopted by the Solid and Hazardous Waste Commission on February 21, 2012 and became effective on March 30, 2012.

9.1.5.DEFINITIONS: for a comprehensive list of definitions, refer to Section 1.2 of these Solid Waste Regulations. The following definitions commonly used relative to this Section 9 are provided for the convenience of the regulated community.

(A)"Ancillary Equipment" as used in this Section 9 means any device, such as, but not limited to, piping, fittings, flanges, valves, or pumps, from the first such equipment upstream from a waste impoundment to the first such equipment downstream of the waste impoundment. All other equipment not included in this definition is not ancillary equipment for the purposes of this Section 9.

(B)"Demonstration Plan" as used in this Section 9 means an evaluation prepared by an existing waste impoundment facility pursuant to Section 9.1.8 of this Section 9 for purposes of classifying one or more waste impoundments at the facility as Type A or Type B.

(C)"Existing facility" as used in Section 9 refers to a facility with waste impoundments that have received solid waste prior to the effective date in Section 9.1.4.

(D)"Facility" as used in this Section 9 means a facility with one or more waste impoundments.

(E)"Site Setting" as used in this Section 9 means the hydrology, geology, hydrogeology, geography, ground water quality, and/or climate at a particular site or impoundment location.

(F)"BSGW/Appendix B" as used in this Section 9 means the ground water quality standards presented in WQCC Regulation 41 (Basic Standards for Ground Water or BSGW; 5 CCR 1002-41), augmented by Appendix B to the Solid Waste Regulations. Appendix B presents a methodology for determining alternate facility- or impoundment-specific enforceable limits for constituents not included in Regulation 41, a methodology for establishing background concentrations in ground water, and a statistical method for evaluating ground water data.

9.1.6CLASSES OF WASTE IMPOUNDMENTS

Classification of waste impoundments, as described below, is based upon the potential for environmental threat, as determined by evaluating the waste stream characteristics and the site setting of the facility. For purposes of this Section 9, waste impoundments are classified without regard to the engineering or operational controls that may already exist or be proposed at the facility. This Section 9 includes two classes of waste impoundments, defined according to potential impact to ground water.

(A)Type A Waste Impoundment

(1) A waste impoundment is considered Type A if it meets one of the following criteria:

(a) Liquid captured from the underdrain system of the waste impoundment has constituent concentrations less than the standards set forth in Regulation 41 (5 CCR 1002-41) Basic Standards for Ground Water (BSGWs) for all constituents relevant to the impoundment's waste stream(s) (if there are multiple waste impoundments at a facility handling the same waste stream and not all waste impoundments are equipped with an underdrain system, then underdrain samples from those impoundments having underdrains may be representative of leaching potential from those not having an underdrain system); or

(b) The constituent concentrations in the liquid fraction of the sludge managed in the waste impoundment is less than the standards set forth in the BSGWs for all constituents relevant to the impoundment's waste stream(s); or

(c) TCLP or SPLP data on the solid fraction of the sludge shows concentrations in the leachate extract to be below standards set forth is the BSGWs for all constituents relevant to the impoundment's waste stream(s).

(2) If insufficient information is available to satisfy the criteria in Section 9.1.6(A)(1), and the concentrations in the influent to the waste impoundment are less than the BSGWs for all constituents, as determined using a Department-approved sampling plan to make sure the sampling results are representative of impoundment conditions given the potential variability in the influent waste stream, the impoundment can still be classified as a Type A impoundment.

(3) Despite failing to meet one of the criteria in 9.1.6(A)(1)or (2), if the facility is able to demonstrate, based on evaluation of waste characteristics and site setting and not considering impoundment design or operations, that there is no reasonable potential to exceed BSGWs at the point of compliance as defined in Section 1.2 of the Solid Waste Regulations, the impoundment can still be classified as a Type A impoundment.

(4) A demonstration that an impoundment meets one or more of the criteria in this section and should be classified as a Type A impoundment is subject to Department approval per Section 9.1.8.

(B)Type B Waste Impoundment

Type B waste impoundments pose risk of adverse impact to ground water, based on the waste type, site setting. Any facility not satisfying the Type A criteria above or not otherwise exempt in Section 9.1.2 is a Type B waste impoundment.

(C) The impoundment classification may be subject to reclassification based on a significant change to the treatment process delivering waste to an impoundment that alters the potential of an impoundment at the facility to impact ground water or cause exposure to individuals in proximity to the impoundment.

9.1.7.COMPLIANCE SCHEDULE

The following compliance schedules apply to certain waste impoundments:

(A) Operators of waste impoundments receiving sludge from the following types of treatment must submit, within nine (9) months of the effective date of this Section 9, either an engineering design and operation plan for a Type B waste impoundment consistent with Section 9.3, or a Demonstration Plan consistent with Section 9.1.8(B) showing that the facility can qualify as Type A on the basis of favorable site hydrogeology:

(1) reverse osmosis,

(2) ion exchange, and

(3) iron filtration.

(B) With the exception of impoundments subject to Section 9.1.2(B), 9.1.7(A) and 9.1.7(C), all other waste impoundments that are not pre-classified must follow the process and schedules outlined in Section 9.1.8 and 9.1.9 below and the requirements of Section 9.2 and 9.3.

(C) Operators of waste impoundments that will be closed and taken out of service consistent with the timelines established in the Clean Air, Clean Jobs Act (HB10-1365) for closure or transition of an electric generating unit must submit, within 12 months of the effective date of this Section 9, a written notice to the Department containing the schedule for planned impoundment closure. These operators must submit, within 24 months of the effective date of this Section 9, a closure plan addressing the applicable provisions of Section 9.3.4(F) and 9.3.6.

(D) Alternative implementation schedules may be proposed to the Department and approved as part of a site-specific closure plan.

9.1.8INVENTORY AND CLASSIFICATION OF IMPOUNDMENTS AT EXISTING FACILITIES

This section applies to existing facilities, except those that are preclassified under Section 9.1.3 and those listed in Section 9.1.7(A).

Existing facilities are required to inventory the impoundments at their facility and propose a classification for each impoundment subject to Department approval. New facilities not receiving waste prior to the effective date of this Section 9 must propose waste impoundment classifications as part of their certificate of designation application, or as part of their engineering design and operation plan submittal, as appropriate.

(A)Inventory and Preliminary Classification Report: Existing facilities subject to this Section 9 must submit an Inventory and Preliminary Classification Report (IPCR) to the Department for review and approval. Existing facilities shall submit the IPCR to the Department within twelve (12) months of the effective date of this Section 9. Water treatment plants other than those listed in Section 9.17(A) serving fewer than 10,000 people may petition to take up to twenty-four (24) months to submit the IPCR.

The IPCR shall include a brief description of all waste impoundments identified at the facility. In addition, for each waste impoundment having sufficient information readily available in order to classify the impoundment, the IPCR should propose a preliminary classification according to the Type A or Type B categories described above. For waste impoundments not having sufficient information on which to propose a preliminary classification, the IPCR will state that fact. In cases of insufficient information, the facility must submit a Demonstration Plan pursuant to Section 9.1.8(B) below after receiving a written determination on the IPCR from the Department.

For each waste impoundment that the facility has attempted to classify, the Department will determine whether the information provided in support of the proposed classification is adequate. This written determination will constitute a final agency action subject to appeal. Facilities obtaining an approved IPCR that was successful in classifying all waste impoundments at the facility may skip 9.1.8(B) below and proceed to development of an engineering design and operation report, if necessary.

(B)Demonstration Plan: Existing facilities without sufficient readily available information with which to classify their waste impoundments in the IPCR must develop a Demonstration Plan. The purpose of the Demonstration Plan is to obtain further information in order to classify one or more waste impoundments at a facility. The facility may request a meeting with the Department prior to submission of the Demonstration Plan. Within twelve (12) months of the date of the Department's written determination on the IPCR, facilities shall submit the Demonstration Plan for Department review and approval. Water treatment plants other than those listed in Section 9.17(A) serving fewer than 10,000 people may petition the Department for an additional twelve (12) months to complete the Demonstration Plan.

(1) The demonstration plan shall include a scope of work and schedule for implementation, and may include any of the following as necessary to complete classification of each impoundment:

(a) Operational history of the waste impoundment;

(b) Chemical characteristics of the waste stream(s) disposed, managed, stored, treated, or processed in the waste impoundment;

(c) Evaluation of the site setting and, through modeling or other appropriate means approved by the Department, evaluate the constituent concentrations relevant to the waste streams received in the impoundment that may occur at the point(s) of compliance without considering existing engineering or operational controls;

(d) Maps and plans, drawn to a commonly recognized engineering scale, that show the following:

i. The location and depth of cut or fill for liners;

ii. The location, dimensions and grades of all surface water control structures, and/or ground water containment structures, if applicable;

iii. The location and dimensions of all surface water containment structures, including those designed to impound contaminated runoff, sludge, or liquids for treatment;

iv. The spatial distribution of engineering, geologic and hydrologic data, and relationship to the proposed facility and each individual impoundment unit;

v. The location of all proposed monitoring points for surface water and ground water quality;

(e) The design details of the impoundment including size and total volume at capacity;

(f) Sampling of the uppermost aquifer at the point of compliance, as defined in Section 1.2 of these Solid Waste Regulations, for those constituents reasonably expected based on current and historical operations and activities at the facility and for which there is a BSGW. Appendix B of these Solid Waste Regulations may be used to establish background levels for constituents.

(g) The owner or operator of the facility must implement the demonstration plan according to the approved schedule.

(C) The facility shall provide a Demonstration Report summarizing the findings of the Demonstration Plan to the Department for review and approval within three (3) months of completing implementation of the Demonstration Plan.

9.1.9TIMING OF SUBMITTAL OF AN ENGINEERING DESIGN AND OPERATION PLAN

(A) Wthin twelve (12) months of the Division's formal determination approving the proposed IPCR, or within twelve (12) months of the Division's formal determination approving the Demonstration Report in the case of those impoundments for which a Demonstration Report is required, facilities having Type B waste impoundments shall submit a CD application including an EDOP, or for CD-exempt facilities, an EDOP that satisfies the requirements of Section 9.3. The CD application will be reviewed by the Department and approved by the local governing authority. CD-exempt facilities shall submit the EDOP to the Department for approval. The EDOP shall include schedules for implementing and performing the identified activities. For an owner or operator with multiple impoundments, the schedule for implementation may include a prioritization of the impoundments based upon risk, operational constraints and logistical considerations prevailing at the facility. The facility must ensure that all Type B waste impoundments are included in the EDOP. For facilities with both Type A and Type B impoundments, requirements for Type A waste impoundments may be integrated into the EDOP. The facility shall implement the approved EDOP in accordance with the approved schedules.

(B) New waste impoundments constructed after the effective date of this Section 9 must include the waste impoundment evaluation and demonstration required by Section 9.1.8(B) as part of their CD application, or as part of their EDOP submittal if the facility is managing its own waste in its own impoundments.

(C) Alternative implementation schedules may be proposed to the Department and approved on a site-specific basis.

9.2REQUIREMENTS FOR TYPE A WASTE IMPOUNDMENTS

9.2.1DESIGN, CONSTRUCTION AND OPERATIONS

The following design criteria apply to a Type A waste impoundment.

(A)Access control: The owner or operator shall control public access, prevent unauthorized access, provide for site security both during and after business hours, and prevent illegal dumping of wastes. Effective artificial or natural barriers may be used in lieu of fencing.

(B)Stormwater control: Each waste impoundment shall be designed, constructed and maintained to provide:

(1) run-on control and diversion structures to prevent flow into the unit from a 25-year, 24-hour storm, and

(2) a run-off control system to collect runoff from a 25-year, 24-hour storm and control run-off from a 100-year, 24-hour storm. Precipitation that cannot be diverted from the impoundment, and therefore comes in contact with impounded waste, shall be managed as solid waste. Each impoundment shall be designed, constructed and maintained to prevent damage to the containment structure from erosion.

(C)Characterization: The owner or operator of a solid waste facility managing potential TENORM waste in a Type A waste impoundment shall ensure that such wastes are representatively characterized according to their TENORM characteristics. Any wastes characterized as non-exempt TENORM wastes must be disposed of at a facility approved to accept such wastes.

9.2.2FINANCIAL ASSURANCE:

The owner or operator of a Type A waste impoundment shall establish and maintain financial assurance in accordance with Section 4 of these Solid Waste Regulations.

9.2.3SELF-CERTIFICATION

The Department, as deemed necessary, may utilize self-certification checklists in conjunction with their inspections. Any facility that receives a self-certification checklist from the Department must complete the checklist and return it to the Department. Submission of a completed self-certification checklist will substitute for submission of an Annual Report, as required in Section 9.2.4 below.

9.2.4ANNUAL REPORT: By March 1 of each year, the owner or operator of a Type A waste impoundment shall submit an annual report documenting:

(A) the annual volume of waste removed from the impoundment in the previous calendar year;

(B) the disposition of waste removed;

(C) a description of any unauthorized release that occurred;

(D) a description of corrective actions taken to address any such unauthorized release; and

(E) an attestation from the facility that the process generating the waste has not significantly changed and continues to support the original classification.

Submittal of a self-certification checklist for a particular year will substitute for that year's annual report.

9.2.5CLOSURE: The owner or operator of each Type A waste impoundment shall develop a closure plan and submit it for Department approval. The closure plan must present sufficient detail to support the closure cost estimates required in Sections 4 and 9.2.2 above and to enable the Department to evaluate the adequacy of financial assurance. For some Type A impoundments, the scope of the closure plan will be limited to sludge and impacted soil removal, disposal and verification sampling to ensure residual contamination is below acceptable levels in soil and ground water. Type A waste impoundments in which potential TENORM wastes have been managed must address industry-specific TENORM radionuclides in the closure plan. This requirement may be satisfied through process knowledge and waste characterization data representative of waste disposed over the life of the impoundment. If the Department deems process knowledge and waste characterization data to be insufficient, it may require additional sampling for relevant TENORM radionuclides at closure.

(A)Closure Certification: A closure certification report is required to be submitted within sixty (60) calendar days of completion of closure activities which documents all the requirements and conditions of the closure plan have been achieved. The Report must be signed and sealed by a Colorado registered professional engineer and is subject to review and approval by the Department.

9.2.6POST-CLOSURE CARE: The owner or operator of each Type A waste impoundment whose closure activities result in waste disposed in place as a landfill or with levels of residual contamination that exceed unrestricted use must implement a post-closure care plan in accordance with the criteria identified Section 9.3.6.

9.3REQUIREMENTS FOR TYPE B WASTE IMPOUNDMENTS

The design and operation of Type B waste impoundments must not cause exceedances of BSGWs/App. B at the point(s) of compliance. The extent of engineering and operational controls necessary to satisfy this requirement will vary considerably from facility to facility depending on the potential for groundwater impact. Engineering Design and Operation Plans (EDOP; see Section 9.3.4) have the flexibility to include only the requirements applicable to the unique combination of site setting and waste characteristics at an impoundment. Type B waste impoundment facilities may request alternative, equally protective measures.

Attaining the BSGW/App. B at the point of compliance may be achieved through a prescriptive liner or performance-based alternative design. Performance-based design allows existing facilities to use existing liner systems if those systems can be successfully demonstrated to reasonably ensure groundwater protection, given the unique interplay of waste characteristics, site construction and site setting. New facilities may employ performance-based design to show that a liner system other than a prescriptive liner will be sufficient to meet the design objective of attaining BSGWs/App. B at the point(s) of compliance.

9.3.1FACILITY DESIGN REQUIREMENTS

Type B Waste Impoundments shall comply with the following.

(A)Review by Professional Engineer: All engineered features of the facility design shall be reviewed and sealed by a Colorado registered professional engineer.

(B)Liner Design Requirements

Waste impoundment design and operation can utilize either prescriptive or performance-based alternative liner designs that, in conjunction with waste characteristics and site setting, ensures attaining BSGWs/App. B at the point(s) of compliance, taking into consideration background concentrations. It is recommended that the liner design also consider the constructability, operation and maintenance of the waste impoundment. This will facilitate selecting the design approach and optimizing the design specific elements and features.

Each waste impoundment shall be lined with a composite liner, a double liner system, or an alternate liner system of performance based alternative design. In addition, the facility design must include leak detection monitoring. The owner or operator of the facility shall demonstrate to the Department that the design developed for the facility will comply with this Section 9 and Sections 1 and 2 of these Solid Waste Regulations, and with BSGW/App. B.

(1)Composite Liner System: A composite liner shall consist of an upper and lower component.

(a) The upper component shall consist of a minimum 60-mil high-density polyethylene (HDPE) liner and shall be installed in direct and uniform contact with the lower component.

(b) The lower component shall consist of at least a two-foot layer of compacted soil with a hydraulic conductivity less than or equal to 1 X 10^-7 cm/sec.

(2)Double liner system: A double liner system shall consist of an upper liner and a lower liner separated by a drainage layer.

(a) The upper liner shall consist of a minimum 60-mil HDPE liner and shall be installed in direct contact with the underlying underdrain material.

(b) The drainage layer contains transmissive material such as sand, gravel or a synthetic drainage blanket, and conveys liquid to a sump from which it can be extracted. This type of layer incorporates leak detection capability directly into the design, and may warrant a smaller scale groundwater monitoring program, subject to Department approval.

(c) The lower liner shall consist of a minimum 60-mil HDPE liner and shall be installed in direct contact with the underlying prepared soil.

(3)Performance-Based Alternative liner designs: Alternative liner designs, including single liner systems, entailing liner designs that, in conjunction with waste characteristics and site setting, ensure that BSGWs/App. B can be met at points of compliance, may be approved by the Department based on a demonstration of the alternate liner design's performance, the waste type and site specific technical information.

(C)Leak Detection Monitoring: Owners/Operators must include leak detection monitoring consistent with the liner design specific to that impoundment.

(1) Single liner and composite liner systems must incorporate one or more of the following based on the evaluation above:

(a) Vadose Zone Monitoring (wet/dry wells);

(b) Resistivity net monitoring;

(c) Downgradient impoundment edge ground water monitoring; or

(d) Another equivalents protective monitoring system as approved by the Department.

(2) In a double liner system, the leak detection system may be incorporated into the interstitial drainage layer. If this is done, sampling of leak detection liquids must be performed immediately upon discovery. If the leak detection system is not incorporated into the interstitial drainage layer, the requirements of Section 9.3.1(C)(1) must be met.

(D)Fluid Level Measurement: Maximum liquid level in the waste impoundments shall be capable of being measured at any time or continuously so that each impoundment has a minimum of two (2) feet of freeboard (or an alternate amount of freeboard as approved by the Department), measured from the lowest elevation berm of a specific impoundment to the upper surface of the impounded waste. Fluid level measurement points for each impoundment shall be established, and continuously maintained.

(E)Access Control: Owners and Operators shall control public access and prevent unauthorized access, provide for site security both during and after business hours, and prevent illegal dumping of wastes. Effective artificial or natural barriers may be used in lieu of fencing.

(F)Stormwater Control: Each waste impoundment shall be designed, constructed and maintained to provide:

(1) run-on control and diversion structures to prevent flow into the unit from a 25-year, 24-hour storm, and

(2) a run-off control system to collect runoff from a 25-year, 24-hour storm and control run-off from a 100-year, 24-hour storm. Precipitation that cannot be diverted from the impoundment, and therefore comes in contact with impounded waste, shall be managed as solid waste. Each impoundment shall be designed, constructed and maintained to prevent damage to the containment structure from erosion.

(G)Embankment Durability: Embankments shall be designed and maintained to minimize erosion and to withstand deterioration caused by the impounded waste such that the integrity of the impoundment is maintained.

(H)Ground Water Monitoring System: The ground water monitoring system must comply with each requirement in Appendix B. Except as otherwise noted in this Section 9, monitoring parameters must be established based on the hydrogeologic data related to the site, background concentrations in ground water, the type of waste stream(s) accepted at the facility and waste characterization analyses performed on incoming wastes. Waste impoundments equipped with leak detection capability may have conditional groundwater monitoring requirements that are only triggered if and when a leak is detected.

9.3.2FACILITY CONSTRUCTION REQUIREMENTS

(A)Construction: Facilities with Type B impoundments must implement their approved quality assurance and quality control plan (QA/QC) during construction of all engineered structures and appurtenances. The QA/QC Plan must be reviewed and approved by the Department prior to commencing construction of any waste management features at the facility.

Note: The Department has guidance on construction quality assurance and as-built documentation on the Department's website, http://www.cdphe.state.co.us/hm/sw/swpubs.htm.

(B)Construction Certification Report: The owner or operator of a new Type B waste impoundment shall submit a construction certification report to the Department for approval at least ninety (90) calendar days prior to the commencement of waste acceptance into the impoundment. For existing facilities, the facility may submit the report and resume waste disposal operations.

However, if a problem comes to light during Department review and prior to approval of the construction certification report, a compliance schedule will have to be developed for implementation of any corrective actions needed.

The construction certification report shall certify that the construction has been completed in accordance with the facility's approved EDOP and approved QA/QC Plan. The construction certification report shall be signed and sealed by a Colorado registered professional engineer approved by the Department prior to the acceptance of waste. Construction certification reports shall be developed, approved and implemented for all engineered structures and ancillary equipment used to manage solid waste at the facility.

(C)Synthetic Liners:Synthetic liners shall be installed according to the manufacturer's instructions, which shall be submitted as part of the facility's EDOP.

(D)Testing: The construction will be tested and evaluated using quality control and quality assurance measures and methods specified in the facility's approved QA/QC Plan as part of the facility's EDOP.

(E)Liner Protection: During construction and prior to the addition of liquid wastes, liner systems shall be protected from erosion, desiccation, drying, degradation from ultraviolet radiation or other damage.

9.3.3FACILITY OPERATION REQUIREMENTS

The owners or operator shall operate a Type B Waste Impoundment in accordance with the approved EDOP.

(A)Ground water Monitoring: The owner or operator shall conduct groundwater monitoring in accordance with the approved ground water monitoring plan which is part of the facility's EDOP.

(B)Surface Water Monitoring: The owner or operator shall conduct surface water monitoring, including monitoring of seeps, where seepage has been detected or other releases have been identified.

(C)Fluid Level Measurement: The owner or operator shall conduct fluid level and freeboard level measurement for each impoundment in accordance with the approved EDOP.

(D)Contingencies: The owner or operator shall implement and maintain the approved contingency plan which is part of the facility's EDOP. It will be implemented in the following situations:

1) an unplanned release from a waste impoundment,

2) leachate observed in the leak detection system for any waste impoundment outside of the normal or design range, and/or

3) any condition of noncompliance necessitating corrective action at any waste impoundment.

(1) The owner or operator shall notify the Department within twenty-four (24) hours of any identified release from a waste impoundment or ancillary equipment or any incident requiring implementation of the Contingency Plan. Within seven (7) calendar days of the incident, the owner or operator shall provide written notification outlining immediate actions taken.

(2) A detailed written assessment of the impact of leakage, repair completion and verification, and the need for additional monitoring and proposed corrective action shall be submitted by the owner/operator within forty five (45) calendar days to the Department. Repairs affecting an engineered feature at the facility must be certified by a Colorado registered professional engineer in accordance with these Regulations.

(E)Waste Impoundment Inspections: The owner or operator of the facility shall implement a periodic impoundment inspection program which will be described in the facility's EDOP. The inspection provisions shall cover all waste treatment, disposal, containment and storage features at each waste impoundment. At a minimum, these inspections shall examine ground movement, cracks, erosion, leaks, equipment connections, influent and effluent locations, rodent burrows, vegetation growing on a liner system, damage to ancillary equipment, spills, detection of liquids in sumps, fires or explosions, or other events or problems which could affect the operation of the facility or jeopardize the integrity of an impoundment. Leak detection and collection systems shall also be inspected weekly, or at the frequency established in the approved EDOP, for the presence of any liquids. If liquids are detected in quantities exceeding the design leakage rate, samples shall be taken and analyzed immediately, and a determination made as to the source of the liquid in the leak collection system. Other aspects of the waste containment system, including ancillary equipment, shall be inspected on a periodic basis as well.

(F)Waste Characterization For Impoundments Accepting Only Wastes Generated On-site:

Waste impoundments accepting only wastes generated on-site shall initially profile each waste stream entering the impoundments and then update the profile as necessary to account for significant changes to the waste generation process. For those Type B waste impoundments accepting potential TENORM waste, the waste profile must include characterization for TENORM radionuclides. Existing facilities may use the Demonstration Report to establish the initial waste profile.

(G)Waste Characterization For Impoundments Accepting Wastes From Third Parties: If a facility receives wastes generated by third parties, the owner or operator of the facility shall implement its approved waste characterization plan which is part of the facility's EDOP to ensure that only approved waste is disposed of at the facility and to ensure that no hazardous waste is received at the facility. For any facility, the disposal of waste streams different from those originally approved shall constitute a significant change in operation and require an approval by the Department prior to acceptance at the facility. An amendment to the facility's EDOP or certificate of designation may be required.

(1) The owner or operator of each waste impoundment facility shall initially profile and then conduct annual testing on each waste stream entering the impoundments to demonstrate conformance with the original analyses. Each facility must also ensure that solid waste generators using the facility notify the facility when there has been a change in their processes or waste composition.

(2) The owner or operator of each waste impoundment facility shall analyze at least one sample of the contents of each impoundment annually for the suite of reasonably expected constituents included in Appendix II of the Solid Waste Regulations. Such analysis shall be performed using appropriate methods to provide an accurate representation of constituents and concentration levels found in the waste. If the impounded wastes are subject to stratification, a separate sample shall be taken from each representative level, including settled sludge and oil or other surface accumulation. Analysis of such sampling results will be submitted to the Department within 30 days of when they become available to the facility, along with a proposal of the suite of analytes to be analyzed on an annual basis. The facility will annually submit results of sampling for the suite of approved analytes.

(3) Annual testing of unannounced grab samples shall be taken from random vehicles entering the facility and analyses conducted for the original or approved amended list of parameters. If any waste is found to differ from the original analysis, the Department shall be notified in writing within seven (7) calendar days, and a request to modify the design and operation plan submitted to the Department for review and approval prior to continuing acceptance of the identified waste stream.

(4) Solid waste disposal facilities shall not receive hazardous waste and will conduct waste profiling in accordance their approved waste characterization plan.

(5) A facility may propose alternative waste characterization methods to those presented in Sections 9.3.3(G)(1) through (G)(4).

(6) Type B waste impoundment facilities accepting waste from third parties must also comply with Section 2.1.2 (C)(5) provisions related to TENORM waste.

(H)Personnel Training Plan: The facility shall implement the approved personnel training plan.

(I)Commingling of Waste: Incompatible wastes shall not be commingled. The disposal of waste streams different from those originally approved shall constitute a significant change in operation and require an approval by the Department prior to acceptance at the facility. An amendment to the facility's EDOP or CD may be required.

(J)Financial Assurance: The owner or operator shall maintain financial assurance of an adequate amount to cover closure and post-closure care costs in accordance with Section 4 of these Solid Waste Regulations.

9.3.4ENGINEERING DESIGN AND OPERATIONS PLAN

The owner or operator of each Type B waste impoundment shall submit an engineering design and operation plan (EDOP) to the Department for review and approval, per the schedule in Section 9.1.9 for existing waste impoundments, and prior to commencing impoundment construction, storage, treatment or disposal operations for new impoundments. The EDOP shall describe how the facility will comply with all applicable requirements in these Solid Waste Regulations. Facilities may use existing general, design, construction and operating documentation to satisfy these requirements.

The EDOP shall include the following subject areas, as appropriate. Given the diverse nature of waste impoundment facilities, not all of the following information will pertain to every facility.

(A)General Information:

(1) Owner and Operator mailing address, county and legal description of the facility with waste impoundments;

(2) Map of facility property;

(3) Type of treatment, disposal, storage and containment features, monitoring and operational practices to be used at the facility;

(4) Discussion of facility's service area, including transportation corridors and surrounding access;

(5) The names, qualifications and addresses of the persons operating the facility and having the authority to take corrective action in the event of noncompliance;

(6) The hours and days of operation;

(7) A listing of the waste stream types to be approved for routine receipt and anticipated volumes in barrels or gallons/per day of wastes to be received;

(8) The expected life of the site;

(9) The number and job descriptions of personnel projected to be employed in waste impoundment operations at the facility when operating;

(10) Type of equipment projected to be used in waste impoundment operations at the facility;

(11) The size (surface area and volume) and types of impoundments or processing areas to be constructed;

(12) Provisions to minimize nuisance conditions on-site and prevent nuisance conditions from occurring off-site;

(13) Provisions for fire protection, including the amounts and sources of on-site water available to be used for fire suppression; and

(14) Facility inspections, including the frequency of inspections by the operator and associated written documentation of impoundment and ancillary equipment conditions.

(B)Site Investigation

(1)Geologic Data: The EDOP shall include, as applicable, the following geologic data:

(a) Types and regional thickness of unconsolidated soils and materials;

(b) Types and regional thickness of consolidated bedrock materials; and

(c) Regional and local geologic information, including but not limited to bedrock strike and dip, fracture patterns, slope stability, faulting, folding, rockfall, landslides, and subsidence or erosion potential that may affect the design and operation of the facility for solid wastes disposal.

(2)Hydrologic data. The EDOP shall include, as applicable, the following hydrological data:

(a) Lakes, rivers, streams, springs, or bogs, on-site and within two (2) miles of the site boundary;

(b) Depth to and thickness of perched ground water zones and uppermost aquifers;

(c) Ground water wells within one (1) mile of the point of compliance, including well depth, depth to water, screened intervals, yields and the aquifers tapped, if such information is available in the public records of the Division of Water Resources in the Department of Natural Resources;

(d) Hydrologic properties of the perched zones and uppermost aquifer, including flow directions, flow rates, porosity, coefficient of storage, permeability, and potentiometric surface;

(e) Site location in relation to the base floodplain of nearby drainages;

(f) The separation between the wastes to be impounded and the uppermost waterbearing zone, perched or otherwise;

(g) An evaluation of the potential for impacts to existing surface water and ground water quality from each of the proposed impoundment units, if more than one, or the facility if only one unit exists;

(h) The existing quality of ground water beneath the proposed facility;

(i) Any other associated information related to the time of travel from the midpoint of each cell to the point of compliance;

(j) Climatic information;

(k) The estimated volume, physical and chemical characteristics of the waste;

(I) The distance ground water beneath the site would flow during the facility's operating life and post-closure care period; and

(m) The distance to existing domestic wells or springs.

(C)Facility Design: The EDOP shall include specific design details for each waste impoundment and all associated structures and ancillary equipment used to store, treat or dispose of solid waste.

(1)Engineering Data. The EDOP shall contain, as applicable, the following engineering data:

(a) The types and quantity of material(s) that will be used in the different components of the liner system;

(b) Liner design, liner materials and specifications, liner installation requirements and procedures, and liner QA/QC procedures after installation;

(c) Maps and plans, drawn to a common recognized engineering scale, that show the following;

(1) The location and depth of cut or fill for liners;

(2) The location, dimensions and grades of all surface water control structures;

(3) The location and dimensions of all surface water and groundwater containment structures, including those designed to impound contaminated runoff, sludge, or liquids for treatment;

(4) The spatial distribution of engineering, geologic and hydrologic data, and relationship to the proposed facility and each individual impoundment unit;

(5) The location of all proposed facility structures and access roads;

(6) The location of all proposed monitoring points for surface water and ground water quality;

(7) The final contours and grades of the reclaimed site after closure;

(8) The location of fencing or other access control features to be placed on-site;

(9) The location of each proposed phase of development; and

(10) The design details of the impoundment including size and total volume at capacity.

(d) All designated ancillary equipment associated with each impoundment.

(2)Demonstration of Performance: The EDOP shall reasonably demonstrate that the liner system, in combination with waste characteristics and site setting, will result in constituent concentrations at the point of compliance that are below BSGWs/App. B.

(3)Leak Detection Monitoring: If applicable, the EDOP for Type B impoundments shall describe the leak detection monitoring system installed at each impoundment.

(4)Monitoring and Measurement Systems: The EDOP shall include design specifications for all proposed monitoring points for surface water and groundwater quality and the monitoring system used to make volume and freeboard determinations. For waste impoundment facilities or units equipped with freeboard monitoring, the design details shall be provided in the Report.

(5)Access Control: The EDOP shall describe the access controls at the facility.

(6)Stormwater Control: The EDOP shall provide design details for the stormwater control features.

(7)Embankment Durability: The EDOP shall describe how each Type B waste impoundment shall be maintained.

(8)Ground water Monitoring System: The EDOP shall include design details for the ground water monitoring system and include a plan describing how the facility will comply with each requirement in Appendix B of these Solid Waste Regulations.

(D)Construction: The EDOP for any new waste impoundments, or existing waste impoundments requiring upgrade of engineered features in order to comply with this Section 9, must include a quality assurance and quality control plan (QA/QC) for all engineered structures and appurtenances.

(E)Operations:

(1) The EDOP shall include specific operational details for each waste impoundment and all associated structures or ancillary equipment used to store, treat or dispose of solid waste. The EDOP shall demonstrate how the facility will comply with all regulatory requirements.

(2)Sitewide Monitoring Plan: The EDOP shall include a sitewide monitoring plan, inclusive of ground water monitoring, surface water monitoring, leak detection monitoring, fluid-level monitoring, and inspections.

(3)Contingency Plan: The EDOP shall include a contingency plan for the facility.

(4)Waste Characterization Plan: Each facility receiving waste from off-site shall have as part of its EDOP a Waste Characterization Plan (WCP). The WCP shall describe how procedures employed at the facility to demonstrate compliance with Section 2.1.2 of these Solid Waste Regulations and to ensure that only approved wastes are disposed of at the facility.

(5)Personnel Training Plan: The EDOP shall include a personnel training plan that includes the following provisions:

(a) Annual training on the facility's EDOP , all attachments to the plan and all documents referenced in the plan that are relevant to operational compliance, and

(b) Annual training in the recognition and exclusion of hazardous and prohibited wastes.

(F)Closure Plan: The EDOP shall include a closure plan that describes the steps necessary to close each impoundment at any point during its active life and at the end of the facility's active life. The facility may either:

1) close the waste in place as a solid waste landfill in accordance with these Solid Waste Regulations, or

2) remove all solid waste and residual contamination to meet unrestricted use concentrations. Option 2, also known as "clean closure," eliminates the need for post-closure care. Both Option 1 and Option 2 require the owner or operator of a waste impoundment to develop a closure plan.

(1) The closure plan shall include the following information consistent with Section 9.3.6:

(a) Provisions for removal of all solid waste at the site and decontamination of all ancillary equipment at the site, or closure of the waste impoundment with waste in place as a landfill;

(b) Provisions for removing all liquid wastes from the impoundments;

(c) Proposed plans and procedures for sampling and testing soil and ground water at the site, to include industry-specific TENORM radionuclides if the site accepted TENORM waste or potential TENORM waste during site operations;

(d) Provisions for sampling and testing of residual materials, such as sludge and soil, and provisions for final disposal, to include industry-specific TENORM radionuclides if the site accepted TENORM waste or potential TENORM waste during site operations. For purposes of satisfying this provision and (F)(1)(c), process knowledge and waste characterization data representative of wastes disposed over the life of the impoundment may be used to justify that further characterization for TENORM radionuclides at closure is not necessary. If the Department deems process knowledge and waste characterization data to be insufficient, it may require additional sampling for relevant TENORM radionuclides at closure.

(e) Provisions for a Background Study which must include, at a minimum, the following:

(i) Sampling Plan;

(ii) Analysis Plan;

(iii) Data Evaluation Plan;

(iv) Determination of relevant background concentrations;

(f) General description of the site post-closure, including:

(i) the final property contours, material and procedures to be used to fill the impoundments;

(ii) A description of final soil placement and establishment of plant life;

(iii) A description of anticipated land use; and

(iv) A schedule for completing all activities necessary to satisfy the closure criteria of this section.

(g) An analysis of whether an environmental covenant will be necessary following closure.

(h) An analysis of whether post-closure care will be necessary and, if so, a post-closure plan consistent with the requirements of Section 9.3.7.

(i) Cost estimates for closure and post-closure and proof of financial assurance equal to or greater than those cost estimates consistent with Section 4 of the solid Waste Regulations.

9.3.5RECORDKEEPING AND REPORTING REQUIREMENTS

Not all of the requirements below will apply to facilities disposing of or managing their own waste on their own property. Such facilities may note in their EDOP any of the requirements below that are not applicable.

(A)Record Availability: for facilities with waste impoundments, all records required by Section 9.3.5, shall be maintained on-site for a minimum of three (3) years unless otherwise approved by the Department and shall be available for inspection by representatives of the Department during regular business hours.

(B)Incoming Shipments: for facilities receiving third party wastes, each shipment of solid waste being disposed of in a waste impoundment shall be registered, with the following information entered on a single receipt or manifest:

(1) Date and time;

(2) Receiving impoundment identification;

(3) Quantity;

(4) Type of waste;

(5) Location produced;

(6) Waste generator;

(7) Hauler and truck number; and

(8) Driver's name and signature.

(C)Monthly Summaries: All facilities shall maintain monthly summaries, including the total volume of each waste stream managed or disposed in each waste impoundment.

(D)Annual Report: All facilities shall submit an annual report by March 1st of each year to the Department. The annual report shall include:

(1) the total volume received of each waste type during the previous calendar year;

(2) the waste removed from each impoundment during the previous calendar year, not including interbasin transfers, with location details provided for final disposition of the waste;

(3) any unplanned releases from an impoundment unit at the facility during the previous calendar year; and

(4) for waste impoundments receiving third party wastes, documentation proving that no hazardous waste has been received (per Section 2.1.2) and random load screening results.

(5) an annual ground water monitoring report, where one is required in the EDOP.

(E)Routine Monitoring: All facilities with Type B waste impoundments shall maintain records of monitoring data including ground water monitoring data, fluid level monitoring data, equipment and impoundment inspection logsheets, and precipitation data.

(F)Inspections: Records shall be maintained by all facilities with Type B waste impoundments that fully document all inspections, fluid level measurements, damage, repairs and repair verifications to impoundments, the liner systems or ancillary equipment.

(G)Reporting Requirements:

For facilities receiving third party wastes, waste characterization results indicating excursions from the facility's approved plans, such as inadvertent receipt of unapproved wastes, shall trigger notification in writing to the Department within seven (7) calendar days after receipt of such results by the owner or operator.

The owner or operator of the facility shall notify the Department within 24 hours of conditions not in substantive compliance with the approved design and operations plan and/or any situation that could cause a violation of the approved operations plan (e.g. major precipitation events, fire, other examples of force majeure). The facility shall remedy the situation as soon as possible, implement contingency plans as appropriate, and notify the Department again following any corrective actions.

9.3.6CLOSURE REQUIREMENTS

(A) Owners and Operators of Type B impoundments shall close the impoundments only in accordance with the approved Closure Plan in the facility's EDOP.

(B) Individual impoundments at a facility may be closed independently of closure of the entire facility.

(C) At least sixty (60) days in advance of the proposed closure date, the owner or operator of a facility receiving third party wastes open to the public must notify the Department and place signs of suitable size at the entrance to the site and facility.

(D) The owner or operator of the facility must complete closure activities of the facility in accordance with the closure plan and within one hundred eighty (180) calendar days following the final receipt of waste, or according to the implementation schedule in the approved closure plan.

(E) Following closure of an impoundment facility, the owner or operator shall work with the Department to place an Environmental Covenant on the former impoundment area in compliance with C.R.S. § 25-15-320 if waste is left in place as part of the closure or the site is not suitable for unrestricted use. If waste is left in place and/or the site is not suitable for unrestricted use, the owner or operator must comply with Section 9.3.7.

(F)Closure Certification: A closure certification report is required to be submitted within sixty (60) calendar days of completion of closure activities which documents all the requirements and conditions of the closure plan have been achieved. The Report must be signed and sealed by a Colorado registered professional engineer and is subject to review and approval by the Department.

9.3.7POST-CLOSURE CARE AND MAINTENANCE REQUIREMENTS

(A)Post-Closure Care Plan: Within sixty (60) days of receiving an approved closure certification report for an impoundment with waste left in-place or with residual contamination such that the site is not suitable for unrestricted use, the owner or operator shall submit a Post-Closure Care Plan for Department review and approval that will include at least the following.

(1) Provisions to prevent nuisance conditions;

(2) Provisions to maintain the integrity and effectiveness of the final cover, should waste be closed in place, including making repairs to the cover and replanting vegetation as necessary;

(3) Provisions to monitor ground water and maintain the ground water monitoring system, if applicable;

(4) The name, address, and telephone number of the person or office to contact about the facility during the post-closure period;

(5) A description of the planned uses of the property during the post-closure period. Post-closure use of the property shall not disturb the function of the cap and monitoring systems unless reviewed and approved by the Department; and

(6) Provisions to comply with the Environmental Covenant or Notice of Environmental Use Restriction.

(B) The owner or operator must implement the approved post-closure care plan in accordance with the approved schedule. This includes placing an Environmental Covenant or Notice of Environmental Use Restriction on the waste impoundment areas and any others areas with remaining contamination per Section 9.3.6(F).

(C)Post-Closure Certification: Following completion of the post-closure care period the owner or operator must submit a post-closure certification signed by an independent Colorado registered professional engineer for approval, verifying that post-closure care has been completed in accordance with the post-closure plan.

(D)Post-Closure Duration: Post-closure care must be conducted for a minimum of thirty (30) years. The length of the post-closure care period may be:

(1) Decreased by the Department if the owner or operator demonstrates that the reduced period is sufficient to protect human health and the environment; or

(2) Increased by the Department if it is determined that the lengthened period is necessary to protect human health and the environment.

6 CCR 1007-2-9

37 CR 17, September 10, 2014, effective 9/30/2014

37 CR 24, December 25, 2014, effective 1/14/2015

38 CR 11, June 10, 2015, effective 6/30/2015

38 CR 23, December 10, 2015, effective 12/30/2015

39 CR 23, December 10, 2016, effective 12/30/2016

39 CR 23, December 25, 2016, effective 12/30/2016

40 CR 05, March 10, 2017, effective 4/14/2017

40 CR 21, November 10, 2017, effective 1/1/2018

40 CR 21, November 10, 2017, effective 3/1/2018

41 CR 06, March 25, 2018, effective 4/14/2018

41 CR 11, June 10, 2018, effective 6/30/2018

41 CR 11, June 10, 2018, effective 7/15/2018

41 CR 24, December 25, 2018, effective 1/14/2019

42 CR 06, March 25, 2019, effective 4/14/2019

42 CR 11, June 10, 2019, effective 6/30/2019

42 CR 21, November 10, 2019, effective 11/30/2019

43 CR 06, March 25, 2020, effective 4/14/2020

43 CR 12, June 25, 2020, effective 7/15/2020

43 CR 18, September 25, 2020, effective 10/15/2020

43 CR 24, December 25, 2020, effective 1/14/2021

44 CR 24, December 25, 2021, effective 1/14/2022

45 CR 17, September 10, 2022, effective 9/30/2022

45 CR 23, December 10, 2022, effective 12/30/2022