A liner system is required by statute for all commercial solid waste disposal sites and facilities managing EP waste.
17.3.1
Design Requirements
17.3.1(A)
Liner System
17.3.1(A)(1)
Liner Requirements: The statutory performance requirement for EP waste disposal facilities is to prevent migration of EP waste to groundwater. Therefore, each waste impoundment covered by this section shall be lined with a composite liner as described in Section 17.3.1(A)(2) or a double liner system as described in Section 17.3.1(A) (3), and the facility design must include leak detection monitoring in accordance with Section 17.3.1(C) to prevent the migration of EP waste or EP waste constituents to groundwater. The owner or operator of the facility shall demonstrate, to the Department and the local governing authority, that the design developed for the facility will comply with this Section 17 and Sections 2.1.15 and 2.2 of these Solid Waste Regulations, and with Regulation 41 (5 CCR 1002-41). Such demonstration shall be subject to Department approval.
17.3.1(A)(2)
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). The upper component shall be installed in direct and uniform contact with the compacted soil component; and
(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.
17.3.1(A)(3)
Double liner system: A double liner consists of two liner systems separated by a drainage or leak detection layer. Each of the liner systems may be comprised of a single or composite liner configuration. At a minimum, a) one of the liner systems must incorporate a 60-mil HDPE or equivalent liner material as one of its liner components, and b) the other liner system must be equivalent to a two-foot layer of compacted soil with a hydraulic conductivity less than or equal to 1 x 107 cm/sec. The drainage layer between the liner systems 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 liner incorporates leak detection capability directly into the design, and may warrant the Department's consideration of a modified Appendix B groundwater monitoring program.
17.3.1(A)(4)
Separation from Groundwater: At a minimum, the facility shall ensure a separation of twenty (20) feet between the bottom of the liner system and the uppermost occurrence of groundwater.
17.3.1(A)(5)
Alternative liner designs: Alternative liner designs that perform in an equivalent manner to the Section 17.3.1 (A) (2) or (A)(3) liner systems may be approved by the Department and the local governing authority based on a demonstration of alternate liner design's equivalent performance, the waste type and site specific technical information. At a minimum, the upper liner component shall be a 60-mil HDPE or equivalent synthetic liner. Proposals for alternative designs shall also demonstrate that the facility can comply with Sections 2.1.15 and 2.2 of these Solid Waste Regulations, and with Regulation 41 (5 CCR 1002-41).
17.3.1(B)
Mandatory Set-Backs: for EP waste disposal facilities whose application for certificate of designation is submitted to the local governing authority after the effective date of this Section 17, the facility must have a mandatory set-back of one-half mile from all residences, educational facilities, day-care centers, hospitals, nursing homes, jails, hotels, motels, other occupied structures, or outside activity areas such as parks and playing fields.
17.3.1(C)
Leak Detection Monitoring System: All EP waste impoundments must include leak detection monitoring consistent with the liner design specific to that impoundment.
17.3.1(C)(1) Composite single liner systems must incorporate one of the following:
(i) Vadose Zone Monitoring (wet/dry wells);
(iii) Downgradient impoundment edge groundwater monitoring; or
(iv) Other equivalents protective system as approved by the Department.
17.3.1(C)(2)
Double liner system: The leak detection is incorporated into the interstitial drainage layer. Sampling of leak detection liquids must be performed immediately upon discovery. Downgradient point-of-compliance groundwater monitoring shall be conducted, as necessary, based upon history of impoundment liquids detected in the leak detection system.
17.3.1(D)
Continuous Freeboard Monitoring: All waste impoundment facilities or units shall be equipped with a means to, at all times, quickly and accurately determine the total volume of waste and amount of freeboard in each impoundment.
17.3.1(E)
Access Control: Each waste impoundment covered by this section shall be equipped with fencing and netting to prevent the public and wildlife from accessing the waste disposal facility. Facilities shall control public access, prevent unauthorized access and provide for site security both during and after business hours, and prevent illegal dumping of wastes. Effective artificial barriers or natural barriers as approved by the Department may be used in lieu of fencing.
17.3.1(F)
Stormwater Control: Each waste impoundment shall be designed, constructed and maintained to provide:
(1) a run-on control and diversion structures to prevent flow into the unit from a 25-year, 24-hour storm,
(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.
17.3.1(G)
Embankment Durability: Embankments shall be designed to eliminate erosion and to withstand deterioration caused by the impounded waste.
17.3.2
Construction Requirements17.3.2(A) Waste impoundments shall be constructed according to Department-approved detailed design plans, specifications and criteria. The owner or operator of each facility shall develop and implement a Quality Assurance/Quality Control (QA/QC) program to demonstrate that each engineered containment structure at the facility has been constructed in accordance with the facility's approved Engineering Design and Operation Plan and the facility's approved QA/QC Plan.
17.3.2(B) Synthetic liners shall be installed according to the manufacturer's instructions, which shall be submitted as part of the facility's engineering design and operations plan.
17.3.2(C) The construction will be tested and evaluated using quality control and quality assurance measures and methods specified in the facility's approved Engineering Design and Operation Plan and QA/QC Plan. The resulting QA/QC information, including daily visual observations, moisture, density and hydraulic permeability test results, shall be submitted as part of a construction certification report to the Department and local governing authority for review and approval.
17.3.2(D) During construction and prior to the addition of liquid wastes, liner systems shall be protected from erosion, desiccation, drying, UV degradation or other damage.
17.3.2(E) At least ninety (90) calendar days prior to the commencement of waste acceptance into the impoundment facility, the owner or operator of the facility shall submit the construction certification report to the Department and the local governing authority. This report shall certify that the construction has been completed in accordance with the facility's approved engineering design and operation plan and approved QA/QC Plan. The construction certification report shall be signed and sealed by a Colorado registered professional engineer and shall be subject to Department approval prior to the acceptance of waste. Nothing in these Solid Waste Regulations precludes separate review and approval by the local governing authority as well. Construction certification reports shall be developed, approved and implemented for all engineered structures and ancillary equipment used to manage solid waste at the facility.
17.3.3
Operating Requirements
17.3.3(A)
Compliance with Approved Plans: Operation of waste impoundments shall be in accordance with all approved plans, and with the minimum standards found in Sections 1, 2 and 17 of these Solid Waste Regulations.
17.3.3(B)
Commingling of Wastes: Incompatible wastes shall not be commingled.
17.3.3(C)
Waste Characterization:17.3.3(C)(1) The owner or operator of commercial EP waste disposal facilities shall develop and implement waste analysis procedures to ensure that only EP waste is disposed of at the 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 and the local governing authority prior to acceptance at the facility. An amendment to the facility's certificate of designation may be required.
17.3.3(C)(2) The owner or operator of each commercial EP waste impoundment facility shall initially profile and then conduct annual testing on each waste stream entering the facility, including, at a minimum, waste from each well and/or each tank battery and each drilling location, to demonstrate conformance with the original analyses. Each facility must also ensure that EP waste generators using the facility notify the facility when there has been a change in their processes or waste composition.
17.3.3(C)(3) The owner or operator of each EP waste disposal facility shall analyze at least one sample of the contents of each impoundment annually for the suite of analytes included in Appendix II of the Solid Waste Regulations. Such analysis shall be performed using appropriate methods as specified in the site-wide monitoring plan 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.
17.3.3(C)(4) 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 and local governing body having jurisdiction shall be notified in writing within seven (7) calendar days, and a request to modify the design and operation plan submitted to the Department and local governing authority for review and approval prior to continuing acceptance the identified waste stream.
17.3.3(C)(5) EP waste disposal facilities shall not receive hazardous waste and will conduct waste profiling in accordance with Section 2 and their approved waste characterization plan (as amended to conform to this Section 17).
17.3.3(C)(6) EP waste disposal facilities must also comply with Section 2.1.2 (C)(5) provisions related to TENORM waste.
17.3.3(D)
Liner Protection: The owner or operator of EP waste disposal facilities shall maintain the integrity of liners by prevention of damage through uncontrolled or improper discharge of wastes into the impoundment, vehicle traffic, dredging of settled sludge, skimming and maintenance of spray systems erosion, desiccation, drying, UV degradation or other damage or other actions.
17.3.3(E)
Removal of Surface Accumulation: All evaporative impoundments shall be safeguarded and maintained free of oil or other surface accumulations. Any accumulation of oil or surface accumulations shall be removed within twenty-four (24) hours of discovery. Discovery and removal dates and times shall be documented.
17.3.3(F)
Leak Detection Monitoring: Per statutory requirement, EP waste disposal facilities shall conduct monitoring not only to detect, but also to prevent, releases that impact groundwater. If the liner design incorporates a double liner system, this can be readily accomplished through monitoring of the drainage layer. However, if the liner design consists of a single composite liner, monitoring to provide leak detection capability must be implemented in accordance with Section 17.3.1(C) beneath or adjacent to the impoundment.
17.3.3(G)
Groundwater Monitoring: The owner or operator of a commercial EP waste impoundment facility shall conduct groundwater monitoring in accordance with a Department-approved groundwater monitoring plan. Monitoring parameters shall be established based on the hydrogeologic data related to the site, the type of waste stream(s) accepted at the facility and waste characterization results.
17.3.3(H)
Surface Water Monitoring: Surface water monitoring, including monitoring of seeps, is required where seepage has been detected or other releases have been identified.
17.3.3(I)
Continuous Fluid Level Monitoring: Continuous fluid level and freeboard level monitoring is required for each impoundment. Maximum liquid level shall be measured continuously so that each impoundment has a minimum of two (2) feet of freeboard, 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.
17.3.3(J)
Mass Balance: To ensure the accuracy of the method used for monitoring fluid level and to check for potential liner leaks, monthly monitoring of total volume for each impoundment shall occur.
17.3.3(K)
Attendant: Commercial EP waste impoundment facilities shall maintain at least one trained attendant on site during scheduled business hours and when accepting waste.
17.3.3(L)
Contingencies:
The owner or operator shall develop, implement and maintain an approved contingency plan (See Section 17.2.2(F), engineering design and operation plan) to be implemented in the following situations:
1) an unplanned release from the containment system,
2) leachate observed in the leak detection system and
3) conditions of noncompliance with approved plans or certificate of designation or the Solid Waste Regulations necessitating corrective action. The contingency plan must contain provisions for assessing the full nature and extent of release to delineate the impact to soil, groundwater or surface water, for remedying such impact, and for returning the facility to compliance. If a facility has an approved Spill Prevention Control and Countermeasures (SPCC) Plan, then the Department will accept a modified approved SPCC Plan that also incorporates the additional requirements as specified in these Solid Waste Regulations. If the facility does not have an approved SPCC Plan, then the Contingency Plan must include all of the provisions identified in this Section 17 of the Solid Waste Regulations.
17.3.3(L)(1) As part of the facility's implementation of the contingency plan, the owner or operator shall take the following actions, at a minimum:
(a) Cease adding waste into the impoundment;
(b) Close and empty the impoundment to repair leaks; and/or
(c) Remove any liquid from the leak detection system on a daily basis, or more frequently as necessary; and
(d) Measure and record the volume of waste removed.
17.3.3(L)(2) The owner or operator shall notify the Department and the local governing authority 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.
17.3.3(L)(3) 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 and local governing authority. Repairs affecting an engineered feature at the facility must be certified by a Colorado registered P.E, in accordance with 17.3.2(E)
17.3.3(M)
Facility Inspections: The owner or operator of the facility shall implement a weekly facility inspection program. The inspection provisions shall cover all waste treatment, disposal, containment and storage features at the facility, including tanks and ancillary equipment. 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 for the presence of any liquids. If liquids are detected, 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 tanks and ancillary equipment, shall be inspected on a weekly basis as well.
17.3.3(N)
Financial Assurance: Financial assurance of an adequate amount to cover closure and post-closure care costs shall be established in accordance with Section 4 of these Solid Waste Regulations.