This guidance has been developed to assist Enforcement Agencies (EA) with daily and intermediate cover regulations for disposal sites.
These regulations are contained in Title 27, California Code of Regulations (27 CCR), Division 2, Subdivision 1, Chapter 3, Subchapter 4, Article 2. They were adopted primarily to satisfy Public Resources Code (PRC) Section 41781.3 which establishes that alternative daily cover (ADC) and other waste materials beneficially used at landfills constitutes diversion through recycling, and requires CalRecycle to adopt regulations governing ADC.
CIWMB Alternative Daily Cover (27 CCR 20690)
General standards for all ADC use are specified in subsection 20690(a). Use of specified ADC materials is further addressed by subsections 20690(b)(1-11). Site-specific demonstration projects have shown that the following ADC materials can be used as suitable daily cover if used in accordance with the standards established:
- Foam products
- Processed green material
- Sludge and sludge-derived materials
- Ash and cement kiln dust materials
- Treated auto shredder waste
- Contaminated sediment, dredge spoils, foundry sands, energy resource exploration, and production wastes
- Compost materials
- Processed construction and demolition wastes and materials
- Shredded tires
- Spray-applied cementitious products
If a landfill operator proposes to use an ADC material not within one of the listed categories, or an ADC material from one of the above categories, but used differently than specified in subsection 20690(b)(1-11), a site-specific demonstration project must be approved by the EA with concurrence by CalRecycle prior to implementation. The approval process for ADC demonstration projects is discussed later in this guidance.
An example of an ADC material not within one of the approved categories is material recovery residuals from transfer/processing operations and facilities (MRF fines).
Examples of potential ADC materials within an approved category, but used differently than specified, include sludge products not subject to the public contact prohibition and processed green material exposed as cover for longer than 21 days. The specific standards of subsection 20690(b) would not apply to these ADC uses if authorized from an approved demonstration project. For example, a permitted landfill might use water treatment sludge for ADC and alternative intermediate cover (AIC) in a unique way as described in its Joint Technical Document (JTD) and as successfully tested during a previous demonstration project. If this site-specific use of water treatment sludge was successfully tested without the public contact prohibition and material control conditions of 20690(b)(4), the site-specific conditions of the solid waste facility permit that govern this specific operation and 20690(b)(4) would not apply.
Subsection 20690(a)(6) refers to State Water Resources Control Board (SWRCB) requirements for waste classification, composition, and liquid percolation (moisture infiltration) aspects of ADC. These aspects of ADC and AIC are implemented by the Regional Water Quality Control Board (RWQCB) as specified in 27 CCR 20705.
Subsection 20690(a)(10) provides the EAs with flexibility in application of ADC standards to disposal facilities other than Municipal Solid Waste Landfills (MSWLF) and MSWLF facilities that qualify for cover material flexibility as specified in 27 CCR 20680(f). ADC standards would be applied to these facilities as necessary to control vectors, fires, odors, blowing litter, and scavenging without presenting a threat to human health and the environment.
CIWMB Cover Performance Standards (27 CCR 20695)
Section 20695 provides objective standards and monitoring frequencies to control vectors, fires, and litter, and to evaluate the suitability of alternative daily or intermediate cover. The section allows for the EA to approve, with concurrence by CalRecycle, alternative cover performance standards.
CIWMB Daily Cover (27 CCR 20680)
Subsection 20680(a) is the basic daily earthen cover standard for MSWLF units to control vectors, fires, odors, litter, and scavenging. Disposed solid waste shall be covered with a minimum of 6 inches of compacted earthen material at the end of each operating day or at a more frequent interval if necessary. For the purposes of the section, the operating day is defined as the hours of operation specified in the solid waste facility permit if operations (e.g., spreading, compaction, and cover) are continuous.
A temporary waiver of the requirement to cover solid waste with a minimum of 6 inches of compacted earthen material can be approved by the EA with concurrence by CalRecycle under subsection 20680(b). A temporary waiver may be issued if a landfill owner or operator demonstrates that there are extreme seasonal climatic conditions that make meeting the daily cover requirements impractical. For instance, extreme seasonal climatic conditions may make the transportation of earthen material impractical (e.g., flooded or impassable access roads) or may make daily cover material unavailable. This temporary waiver should not be encouraged, nor should it be granted for rain conditions, even above-average rain conditions, as the landfill owner or operator in compliance with Sections 20660 and 20670 would have planned and prepared for rainy seasons.
There is no specific minimum or maximum timeline specified in regulations. However, the waiver should be granted for only the shortest period of time necessary. The operator should take all appropriate actions to alleviate the need to continue to require the temporary waiver.
The landfill owner or operator should provide a request for a temporary waiver to the EA and CalRecycle along with (1) the reason(s) why the daily cover requirements are impractical due to the extreme seasonal climatic conditions, and (2) the shortest time period necessary for the landfill owner or operator to alleviate conditions to allow for the use of daily cover. The EA should make an initial assessment of the request, which should include a site visit to verify the conditions. If a site visit is impractical, the EA should verify the information provided by the operator by other available means, including phone calls and information gathering from other agencies. If the EA accepts the request for a temporary waiver, a brief letter from the EA with a description of the problem should be submitted to CalRecycle for concurrence. If CalRecycle concurs, the EA may grant the temporary waiver. If CalRecycle does not concur, then the waiver cannot be granted.
The landfill owner or operator should maintain a record of the day(s) daily cover was not applied and the efforts taken to alleviate the need to continue under the temporary waiver.
Subsection 20680(c) provides EAs with flexibility in application of earthen daily cover requirements to disposal facilities other than MSWLFs (e.g. inert construction and demolition debris landfills pursuant to 14 CCR, Division 7, Chapter 3, Article 5.95, and waste tire monofills pursuant to 14 CCR, Division 7, Chapter 3, Article 5.4). EAs have the authority to apply frequencies and thicknesses of earthen daily cover to these types of facilities as necessary to control vectors, fires, odors, blowing litter, and scavenging without presenting a threat to human health and the environment.
Subsection 20680(d) establishes that contaminated soils defined in 14 CCR 17361(b) and soils with contaminants other than petroleum hydrocarbons are considered earthen material for the purposes of daily cover, and not ADC, if approved for use by the RWQCB and other agencies from which approval is required, which may include the air pollution control district or air quality management district (local air districts) and Department of Toxic Substances Control.
Subsection 20680(e) refers to SWRCB requirements for waste classification, composition, and liquid percolation (moisture infiltration) aspects of daily cover implemented by the RWQCB as specified in 27 CCR 20705.
Subsection 20680(f) allows EAs to approve, with concurrence by CalRecycle, alternative frequencies for daily cover for MSWLFs that accept 20 tons or less of solid waste per day, based on an annual average, upon consideration of the characteristics of local communities (e.g., small population with a low tax base, few practical alternatives, or small amount of waste generated), climatic and hydrogeological conditions (e.g., the distance from groundwater or surface water, gas or leachate generation, and rainfall and wind conditions), and protection of human health and the environment (e.g., vectors, fire, odors, blowing litter, and scavenging is controlled, and the landfill is an adequate distance from residences, agricultural lands, and other receptors). The landfill owner or operator shall provide the EA with the request for alternative frequency along with (1) the justification(s) for implementing an alternative frequency and (2) a record of the most recent year’s annual average tonnage. Any proposal to allow an alternative frequency shall be made available for public review for a minimum of 30 days to allow for public comment. The EA shall send a recommendation to CalRecycle for review and concurrence. If CalRecycle concurs on the alternative frequency, the EA shall grant approval. CalRecycle or the EA may condition, limit, suspend, or terminate an operator’s use of an alternative frequency if it is determined that the alternative frequency would cause harm to public health and safety and/or the environment.
CIWMB Intermediate Cover (27 CCR 20700)
Intermediate cover is compacted earthen material of at least 12 inches placed on the surface of a fill where no additional solid waste will be deposited within 180 days. Subsection 20700(b) allows for the EA to approve, with concurrence by CalRecycle, alternative materials of alternative thickness for intermediate cover. Approved alternative materials can be used as AIC if it has been demonstrated that they control vectors, odors, blowing litter, and scavenging without presenting a threat to human health and the environment. As specified in subsection 20700(d), site-specific demonstration projects are required for use of AIC in order to establish suitability as intermediate cover. The suggested guidelines for AIC site-specific demonstration projects are discussed below.
Subsection 20700(c) refers to SWRCB requirements for waste classification, composition, and liquid percolation (moisture infiltration) aspects of intermediate cover and AIC. These aspects of intermediate cover and AIC are implemented by the RWQCB as specified in 27 CCR 20705.
Demonstration Projects for New Alternative Covers
If site-specific demonstration projects are required for ADC or AIC pursuant to 20690(b) or 20700(d), approval by the EA is required with concurrence by CalRecycle. Concurrence of ADC or AIC demonstration projects by CalRecycle is delegated to the chief of the permitting and assistance branch. Therefore, upon approval by EAs, proposed demonstration projects should be forwarded to the branch chief for a letter of concurrence. EAs are encouraged to contact CalRecycle permitting Point of Contact staff for consultation during the development of demonstration project proposals. The following are suggested guidelines for ADC and AIC site-specific demonstration projects. The demonstration project cannot commence prior to CalRecycle concurrence.
- A site-specific written proposal from the operator/owner should be submitted describing, at a minimum:
- Responsible parties for the project and chain of command
- Time frame of project, which should include the demonstration phase, report phase, and permit application process phase
- Material specifications, stockpiling, processing, placement procedures, and source of materials;
- Maximum time period of exposure as ADC or AIC
- Maximum and minimum compacted thickness for material and the projected quantity of materials to be tested
- Expected ability of the material in meeting the performance requirements of 27 CCR 20690(a) (ADC and AIC) and 20700(b) (AIC)
- Specific environmental monitoring and control measures for the project (e.g. vector monitoring, material testing and quality control, and material quantities)
- ADC or AIC material references should be included, if available (i.e., operator and regulator contacts from other facilities within California and/or other states where the materials have been/are used).
- EAs should determine if the cover performance standards of 27 CCR 20695 are to be applied. If they are applied, the entities performing the monitoring should be noted (e.g., EA or contractor). The EA should apply these standards if there are specific concerns about the materials being tested and additional oversight is deemed necessary to control potential performance problems.
- Compliance with the California Environmental Quality Act (CEQA) shall be established prior to commencement of the demonstration. Under the CEQA guidelines in 14 CCR 15306, demonstration projects may be categorically exempt. In those cases, a copy of the Notice of Exemption, if filed, should be submitted. If the project is not exempt, the environmental document should be submitted along with a Notice of Determination, if filed.
- The operator should notify the RWQCB, local air districts, and other agencies with approval authority of the proposed demonstration project.
- If the application of ADC or AIC materials during the demonstration project is impracticable or does not control vectors, fires, odors, and blowing litter without presenting a threat to human health and the environment, the operator shall revert to the use of compacted earthen material, approved ADC, or approved AIC within a time frame required by the EA.
Prior to proposing a full-scale demonstration project for new ADC materials compatible with the normal waste stream, it is recommended that preliminary pilot projects be conducted to give the operator and product supplier an opportunity to evaluate a new ADC material without being subject to a formal regulatory approval process. An area of the working face would be covered with the new ADC material during the operating day. Approved cover would be used to cover the entire working face and new ADC material at the end of the operating day. Placement on areas of earthen daily or intermediate cover, or where no solid waste is disposed, would not require additional cover and could be observed over multiple days.
EAs should also note activities that may involve daily and intermediate cover, but are not considered alternative covers subject to site-specific demonstration projects. Examples include the beneficial addition of waste materials such as sewage sludge, compost, and mulch for erosion control to enhance the performance of earthen daily or intermediate cover placed at the standard 6-inch or 1-foot minimum compacted thickness. In addition, temporary plastic sheeting may be used over standard earthen cover to enhance leachate control. This type of use is not considered alternative daily or intermediate cover.
Demonstration Project Time Frame for Alternative Daily or Intermediate Cover
A demonstration project should be planned to account for time to complete a data collection phase and a report phase. If the operator believes that the demonstration will be successful and anticipates wanting to make a request for the continued use of the materials after the conclusion of the project, the demonstration project should include the estimated time required to submit and fully process a request for continued use to ensure a smooth transition between a demonstration and the ongoing use of the material under the appropriate authorization. The EA and the operator should agree on the most appropriate time frame necessary to complete a successful demonstration project.
The purpose of the demonstration project is to monitor and record data relative to the performance standards of the proposed ADC or AIC. When enough data has been collected as outlined in the proposed demonstration project, the operator should prepare a final report providing the data, results, and findings from the project. The report should be submitted to the EA for approval and by the EA to CalRecycle for concurrence on the EA’s approval. At that point, the operator can provide a request in the form of an application submittal to the EA for approval to use the material on an ongoing basis. If the demonstration project proposal submitted and approved by the EA with concurrence from CalRecycle included the time required to submit an application and for EA approval, the demonstration can continue. If the demonstration proposal did not include time to gain approval for ongoing use, the use of the material must cease. If the demonstration report is not approved and concurred upon, the continued use of the material must cease. If the operator does not wish to pursue a request for ongoing use of the material, the use of the material must cease.
All operational procedures, performance requirements, environmental monitoring, and control measures outlined in the demonstration proposal shall remain in effect while the EA processes an application for continued use of the material. Consistent with the implementation of a demonstration project or the use of any alternative cover, if at any time the EA determines that the use of the ADC or AIC materials has become impracticable or does not control vectors, fires, odors, and blowing litter without presenting a threat to human health and the environment, the operator shall revert to the use of compacted earthen material, an approved ADC, or an approved AIC within a time frame required by the EA.
To request ongoing use of an approved ADC or AIC in the solid waste facility permit, the operator should begin by submitting an application to amend the Report of Facility Information (RFI) to the EA pursuant to 27 CCR 21665 following the completion of the demonstration phase and reporting phase. For ADC or AIC, this would normally include a revised description of cover operations in the Report of Disposal Site Information (RDSI) or Joint Technical Document (JTD) per 27 CCR 21600(b)(6).
An RFI amendment could be approved and filed to reflect the use of the ADC or AIC if the EA finds it meets the following requirements of 27 CCR 21665(c):
- The use of ADC or AIC is consistent with all applicable certified and/or adopted CEQA documents for the facility in that no subsequent CEQA document is warranted, or if the EA finds that the proposed change is exempt from the requirements of CEQA.
- The use of ADC of AIC is acceptable and consistent with applicable state minimum standards pursuant to 14 CCR and 27 CCR.
- The use of ADC or AIC does not conflict with the terms and conditions of the current solid waste facility permit.
If the EA finds that the use of proposed ADC or AIC does not meet the requirements for a RFI amendment, then the EA will deny the amendment request and should direct the operator to submit an application package for revision of the solid waste facility permit.
More detailed guidance and resources with regard to the RFI amendment and permit processes can be found at CalRecycle’s Permit Toolbox webpage.
Disposal reporting requirements for ADC and AIC are described in 14 CCR, Division 7, Chapter 9, Article 9.2. The disposal reporting is submitted to CalRecycle to determine compliance with the waste diversion mandates of AB 939. ADC and AIC do not include the use of clean or contaminated soil segregated prior to receipt by a landfill; however, loads of materials used for alternative daily cover may include small amounts of soil. More detailed guidance and resources with regard to disposal reporting can be found at the Disposal Reporting System webpage.