Grappling with the Biogas Regulatory Reform Rule -- How RNG Projects are Responding to the Recent Shake Up from the EPA

In June 2023 the EPA passed the Biogas Regulatory Reform Rule, also referred to as BRRR throughout the biogas industry. The BRRR constitutes new set of requirements for registering biogas to Renewable Natural Gas (RNG) projects seeking to obtain RINs through the federal Renewable Fuel Standard Program. In practical terms the BRRR will bring about significant changes for planned, in-construction, and operational RNG assets. One of the major issues cited amongst RNG practitioners is the lack of clarity in the rules around the technical aspects of the regulation. This paper lays out some of the major aspects of BRRR relevant to Biogas Producers (i.e. WRRFs) and provides the latest clarity available from EPA decision making, as well as several case studies of RNG projects taking steps for compliance under the BRRR. Some of the major relevant aspects of the BRRR include: - Requiring each individual entity within the RNG supply chain to be separately registered with the EPA and undergo Quality Assurance Protocols (QAPs). - Requiring all existing and in-construction projects to register by specific timelines to be granted more lenient compliance under Alternative Measurement Protocols (AMPs). - Requiring flow metering equipment for biogas before upgrading to comply with specific metering technical specifications laid out 40 CFR 80.155(a)(1). - Requiring Btu measurement of biogas before upgrading to be measured with independent, dedicated Gas Chromatography (GC) equipment meeting technical specifications laid out 40 CFR 80.155(a)(2). - Providing a pathway for 'mixed digestion' in which a digester treating a mix of municipal sludge and imported food waste can retain a significant portion of D3 RIN classification. TIMELINES As shown in Figure 1, there are major timelines for various types of RNG projects to file registration, to file Alternative Measurement Protocols (AMPs), and receipt of approval by the EPA. Some of the major deadlines and time thresholds include: - Apr 1, 2024 -- window opens for legacy and in-construction projects to file registration allowing compliance with the old rules and AMPs for technical equipment compliance. - July 1, 2024 -- RNG projects must have begun construction by this date to be eligible for in-construction status when consideration for granting of AMPs. - Oct 1, 2024 -- window closes for legacy projects to file registration and AMPs. - Jan 1, 2025 -- EPA to issue decisions on AMPs filed by the Oct 2024 deadline and all legacy projects must have approved registration. This abstract is being written in Oct 2024 just as existing projects have reached the deadline for filing AMPs, with official decisions due back on Jan 2025. At the time of presentation of this paper, there should be more technical clarity available from the EPA based on the decisions rendered in response to these AMPs. BIOGAS PRODUCERS One of the fundamental shifts brought about the BRRR is a requirement for each individual entity within the RIN supply chain to have registration and compliance responsibilities. This new paradigm with each defined entity is shown in Figure 2. It should be noted that 'Biogas Producers' which include municipal WRRFs are defined entities within the supply chain. This is a departure from the old framework in which a single entity, typically a commercial developer or broker, was the sole pathway registrant. This change was intended to enhance transparency and reduce data manipulation within the RIN ecosystem. In practical terms, it means that WRRFs will be required to jump through more hoops to participate in biogas to RNG projects. New activities will include joining data exchange platforms, conducting EPA compliant record keeping, and being subject to quality assurance audits. BIOGAS MEASUREMENT The most direct impact on those designing and constructing RNG projects are the new BRRR technical requirements on biogas measurement, which includes both flow rate and Btu content of 'Biogas' as defined by the EPA. This is also the area in which the most technical clarification is still outstanding. The EPA defines biogas as a gas product that is: 1.At least 52% methane 2.Has not been treated or refined to the extent that is contains 75% methane or greater This has raised many yet unresolved concerns about the practical definition of biogas that will ultimately be accepted by the EPA. For example, there is ambiguity as to whether new required measurements of 'biogas' can occur after treatment steps like H2S removal, compression, moisture removal, and/or siloxane removal. Constructing biogas measurement equipment further upstream in the biogas train has a higher likelihood of meeting EPA biogas definitions but also creates more difficulties in measuring accurately and keeping measuring equipment from degrading. - Filing of AMPs -- legacy or in-construction RNG projects can avoid letter of the law technology compliance if they can demonstrate 'high installation costs' or 'physical difficulty' installing the new equipment. This is done by filing an AMP to demonstrate how alternative equipment to be used meets or exceeds requirements stated in the BRRR. -Metering -- new requirements were intended to increase granularity and timing of data collection. In practice, all biogas meters must comply with standards called out in 40 CFR 80.155 which preclude most biogas metering technology currently used in the industry. As a result, many meter manufacturers have submitted AMPs to get meters approved as alternate technologies. Facilities will also need to submit AMPs to prove they are using acceptable metering technology. A list of currently approved metering AMPs are shown in Table 1. - BTU Measurement -- this is perhaps the most challenging and most ambiguous technical requirement. The rule calls for separate and dedicated GC equipment to continuously measure 'biogas', with continuous measurements defined as once every 15 seconds. Very few, if any projects have provisions for raw biogas GC meters, and there are significant cost and practicality constraints for adding them, especially if 'biogas' cannot be refined to remove corrosive contaminants like H2S and moisture. No clarity is yet available on what will be accepted via AMPs on this item, but some direction is expected via the Jan 2025 responses to AMPs filed for legacy projects. MIXED DIGESTION In a tidbit of good news related to the BRRR, there was a new protocol set forth to allow for 'mixed digestion' which refers to municipal sludge digester that treat predominantly sludge but also import a portion of organic waste such as FOG or manufactured food slurry. Under old frameworks these digesters would be precluded from receiving D3 RINs despite the fact that the majority of their feedstock is cellulosic. Under new rules mixed digesters treating a majority of sludge have the following options to retain D3 RINs: - Accept 25% D3 RINs and 75% D5 RINs based on very conservative analytical derivations of biogas yields per new EPA standards. - Development of a 'baseline' condition for biogas production from only sludge, and that baseline will determine the ceiling amount of D3 RINs that can be generated, with the remainder being counted as D5. As of the writing of this abstract, no project has successfully been registered under this new mixed digester standard. This means many technical aspects of this rule are up for interpretation, especially in regards to requirements for setting baselines. The presentation will elaborate on any recent clarity brought forth on this item. CASE STUDIES Two case studies will be presented, both which are biogas to RNG projects considered to be 'in-construction' by EPA definitions. The paper will present actions taken and available results to bring these projects in compliance with BRRR. City of Mesa, AZ -- 300 scfm (nameplate) triple mass membrane RNG system slated for startup and commissioning in November 2024. Capital Region Water, Harrisburg, PA -- 400 scfm (nameplate) triple mass membrane RNG system slated for startup and commissioning in October 2025.