Introduction For several decades the federal government has funded efforts to explore the feasibility of mitigating the release of greenhouse gases (GHGs) while burning fossil fuels as a source of energy. Carbon capture and storage (CCS)âthe process of capturing manmade carbon dioxide (CO 2 ) at its source, such as a coal-fired power plant, and storing it underground instead of releasing into the atmosphereâhas been proposed as a technological solution for mitigating emissions while using fossil energy. Federal policies on CCS have received support in recent Congresses, including support for research and development (R&D) and expansion of tax credits for carbon storage. The U.S. Fourth National Climate Assessment, released in 2018, states that "the impacts of global climate change are already being felt in the United States and are projected to intensify in the futureâbut the severity of future impacts will depend largely on actions taken to reduce greenhouse gas emissions and to adapt to the changes that will occur." This report focuses on federal policy regarding the underground carbon storage stage of CCS. Underground carbon storage is achieved through geologic sequestration and as an incidental benefit of enhanced oil recovery (EOR), which both use injection by well to place CO 2 into deep subsurface geologic formations. Geologic sequestration involves storing CO 2 by placing it permanently in an underground formation. This process is being tested in the United States and several other countries, including several large-scale late-stage R&D projects. EOR involves injecting CO 2 to produce additional oil and gas from underground reservoirs and has been used in the United States since the 1970s. Both geologic sequestration and EOR are regulated under the Safe Drinking Water Act (SDWA) for the purpose of protecting underground sources of drinking water (USDWs). The U.S. Environmental Protection Agency (EPA) and delegated states administer sections of SDWA relevant to underground injection and carbon storage. The U.S. Department of Energy (DOE) also engages in underground carbon storage through supporting R&D activities. Congress has supported carbon storage via underground injection through recent legislation directing DOE to expand R&D activity and increasing the federal tax credit for underground carbon storage. As Congress considers policies on underground carbon storage, including geologic sequestration and EOR, Members may wish to consider the current regulatory framework and status of federal and federally sponsored activities in this area. This report provides background on underground injection and geologic sequestration processes and related federal R&D. It then analyzes the federal framework for regulating land-based underground injection of CO 2 both for geologic sequestration and EOR. Finally, it includes a discussion of several policy issues for Congress and recent relevant federal legislation. Not covered in this report are research and management of CCS elements not directly related to underground injection, including carbon capture and the pipeline and transportation infrastructure for captured CO 2 . Regulation of geologic sequestration on federal land and offshore geologic sequestration of CO 2 are also beyond the scope of this report. For additional information on the technical aspects of CCS, see CRS Report R44902, Carbon Capture and Sequestration (CCS) in the United States , by Peter Folger. Underground Carbon Storage Process Underground Injection Underground injection has been used for decades to dispose of a variety of fluids, including oil field brines (salty water) and industrial, manufacturing, mining, pharmaceutical, and municipal wastes. Injection wells are also used to enhance oil and gas recovery; for solution mining; and, more recently, to inject CO 2 for geologic sequestration. As of 2018, EPA estimated that there were more than 734,000 permitted injection wells in the United States. According to one estimate, approximately 750 billion gallons (2.8 million tons) of oil field brine are injected underground each year in the United States. CO 2 injection wells are a type of deep injection well used for injection into deep-isolated rock formations. These wells can reach thousands of feet deep. More details on specific well types are provided later in this report. Geologic Sequestration Geologic sequestration is the long-term containment of a fluid (including a gas, liquid, or supercritical CO 2 stream) in subsurface geologic formations. The goal of geologic sequestration of CO 2 is to trap or transform CO 2 emitted from stationary anthropogenic sources permanently underground and ultimately reduce emissions of GHGs from these sources into the atmosphere. CO 2 for sequestration is first captured from a large stationary source, such as a coal-fired power plant or chemical production facility. Although CO 2 is initially captured as a gas, it is compressed into a supercritical fluidâa relatively dense fluid intermediate to a gas and a liquidâbefore injection and remains in that state due to high pressures in the underground formation. The CO 2 is injected through specially designed wells into geologic formations, typically a half a mile or more below the Earth's surface. These formations include, for example, large deep saline reservoirs (underground basins containing salty fluids) and oil and gas reservoirs no longer in production. Research shows that CO 2 could also be sequestered in deep ocean waters or mineralized. Impermeable rocks above the target reservoir, combined with high CO 2 pressures, keep the CO 2 in a supercritical fluid state and prevent migration into shallower groundwater or into other formations. The National Energy Technology Laboratory (NETL) estimates that the total onshore storage capacity in the United States ranges between about 2.6 trillion and 22 trillion metric tons (hereinafter tons in this report) of CO 2 . (For more details, see Appendix A .) By comparison, U.S. energy-related CO 2 emissions in 2018 totaled 5,269 million tons. Theoretically, the United States contains storage capacity to store all CO 2 emissions from large stationary sources (such as power plants), at the current rate of emissions, for centuries. For additional information on the technical aspects of CCS, see CRS Report R44902, Carbon Capture and Sequestration (CCS) in the United States , and CRS Report R41325, Carbon Capture: A Technology Assessment , by Peter Folger. EOR Use of wells to inject CO 2 builds on known processes. Much of the technology is adopted from well-established experience in the oil and gas industry, which as of 2014, injected approximately 68 million tons of CO 2 underground each year in a process known as EOR. Enhanced recovery is also used occasionally in natural gas development. EOR can significantly increase the amount of oil or gas produced from a reservoir. CO 2 is the most common injection agent used in EOR projects. CO 2 injected for EOR most commonly comes from natural sources, such as underground CO 2 reservoirs, but some is also captured from anthropogenic sources, such as natural gas production, ammonia production, and coal gasification facilities. In many cases, the CO 2 is transferred from the source to the injection site by pipeline. The CO 2 is typically injected into depleted oil or gas reservoirs using the existing well infrastructure from the original production process. The injected CO 2 travels through the pore spaces of the formation, where it combines with residual oil. The mixture is then pumped to the surface, where the CO 2 is separated from other fluids, recompressed, and reinjected. Through repeated EOR cycles, CO 2 is gradually stored in the reservoir. NETL reports that generally, between 30% and 40% of the CO 2 is stored in each injection cycle, depending on the reservoir characteristics, through what it terms "incidental storage." This portion of the CO 2 "will be contained indefinitely within the reservoir," according to NETL. In 2017, commercial CO 2 -EOR projects were operating in 80 oil fields in the United States, primarily located in the Permian Basin of western Texas. Some analysts project that the federal tax credit for carbon storage and the potential increased supply of CO 2 from carbon capture could lead to expansion in both the number and locations of CO 2 injection for EOR operations. Federal Research and Development for Underground Carbon Storage Over the last decade, the focus of federal carbon storage R&D efforts, including geologic sequestration and EOR, has shifted from small demonstration projects to exploration of its technical and commercial viability for storing large volumes of captured CO 2 . DOE leads the federal government's underground carbon storage R&D as part of the agency's fossil energy programs. DOE's work includes conducting fundamental laboratory research on wells, storage design, geologic settings, and monitoring and assessment of the injected CO 2 . In 2003, DOE created the Regional Carbon Sequestration Partnerships (RCSP) programâa set of public-private partnerships across the United States to characterize, validate, and develop large-scale field testing of CO 2 injection and storage methods. The RCSP program supports these R&D projects, which include carbon storage through geologic sequestration and EOR, through partnerships with the petroleum and chemical industries and public and private research institutions. Congress has supported DOE's carbon storage work through appropriations and, beginning in 2005, through enacting legislation directing DOE to establish programs in this area. The Energy Policy Act of 2005 (EPAct, P.L. 109-58 ), Section 963, directed DOE to carry out a 10-year carbon capture R&D program to develop technologies for use in new and existing coal combustion facilities. Among the specified objectives of this program, Congress directed DOE, "in accordance with the carbon dioxide capture program, to promote a robust carbon sequestration program" and continue R&D work through carbon sequestration partnerships. EPAct Section 354 directed the agency to establish a demonstration program to inject CO 2 for the purposes of EOR while increasing the sequestration of CO 2 . The Energy Independence and Security Act of 2007 (EISA, P.L. 110-140 ) amended EPAct Section 963 and expanded DOE's work in carbon sequestration R&D and demonstration. EISA Title VII, Subtitle A, directed DOE to conduct fundamental science and engineering research in carbon capture and sequestration and to conduct geologic sequestration training and research. Subtitle A also specifically directed DOE to carry out at least seven large-scale projects testing carbon sequestration systems in a diversity of formations, which could include RCSP projects. Subtitle B directed DOE to conduct a national assessment for onshore capacity for CO 2 sequestration. To date in the United States, nine DOE-supported projects have injected large volumes of CO 2 into underground formations as part of CCS systems or related EOR R&D projects (see Appendix B ). Three of these active projects involve injection into saline formations for geologic sequestration (for demonstration purposes), five involve injection for EOR purposes, and one involves both sequestration and EOR. Four of these projects are currently injecting and/or storing CO 2 . The Petra Nova facility in Texas is the first operating industrial-scale coal-fired electricity generating plant with a CCS system in the United States. The captured CO 2 is transported by pipeline to an oil field where it is injected for EOR. The project is jointly owned by several energy companies and was partially funded by DOE. In Decatur, IL, ADM is injecting CO 2 from its ethanol production plant into an onsite sandstone formation for geologic sequestration. The Air Products Carbon Capture Project in Port Arthur, TX, has been injecting CO 2 captured from steam methane reformers since 2013 as part of EOR operations. Each of these projects received funds from the American Recovery and Reinvestment Act (ARRA, P.L. 111-5 ). The Michigan Basin Project in Otsego County, MI, is injecting CO 2 from a natural gas facility for EOR. DOE provides partial funding for this project through the RCSP program. All of the projects operate through collaborations among DOE, industry, and local research institutions. Five other projects that injected CO 2 were implemented through the RCSP program. The projects included sequestration into various underground formations and storage associated with EOR with volumes of CO 2 injected and stored ranging from a few hundred tons to over 1 million tons (considered commercial-scale). The RCSP program is currently in the development phase, which DOE defines as large-scale field testing of high volumes of CO 2 storage. These projects have completed injection and are now in the post-injection monitoring phase. All of the existing RCSP projects are scheduled to end by July 2022, but DOE is in the process of selecting additional projects for the program. In the United States, while numerous large-scale storage R&D projects are ongoing, none of the projects injecting CO 2 solely for geologic sequestration are operating in a commercial capacity. Worldwide, public-private partnerships have implemented several CO 2 geologic sequestration projects in diverse regions. There are two active projects, both in Norway, where facilities at the Sleipner Gas Field in the North Sea and Snohvit in the Barents Sea conduct offshore sequestration under the Norwegian continental shelf. Chevron's Gorgon Injection Project, a natural gas production facility in Australia, plans to begin sequestering CO 2 in 2020 and store a total of 100 million tons of CO 2 . Canada, Japan and Algeria have carried out smaller-scale CCS projects with sequestration in saline reservoirs. Federal Framework for Regulating Geologic Sequestration of CO2 and EOR This section provides an overview of the federal framework for regulating underground injection of CO 2 for both geologic sequestration and EOR. It describes the primary federal statute for underground injection control (UIC), the general federal and state roles in developing and implementing UIC regulations, and the UIC well classes. The section analyzes the differences between wells used solely for geologic sequestration and wells used for EOR. It also outlines the regulatory requirements for transitioning from EOR wells to geologic sequestration wells. SDWA SDWA is the primary federal statute governing underground injection activities in the United States, including those associated with geologic sequestration of CO 2 . SDWA Section 1421 directs EPA to promulgate regulations for state UIC programs to protect underground sources of drinking water and prohibits any underground injection activity except when authorized by a permit or rule. The statute defines underground injection as "the subsurface emplacement of fluids by well injection." Federal and State Roles EPA issues regulations for underground injection, issues guidance to support state program implementation, and in some cases, directly administers UIC programs in states. The agency has established minimum requirements for state UIC programs and permitting for injection wells. These requirements include performance standards for well construction, operation and maintenance, monitoring and testing, reporting and recordkeeping, site closure, financial responsibility, and (for some types of wells) post-injection site care. Most states implement the day-to-day program elements for most categories of wells, which are grouped into "classes" based on the type of fluid injected. Owners or operators of underground injection wells must follow the permitting requirements and standards established by the UIC program authorities in their states. SDWA authorizes EPA to delegate primary enforcement authority for UIC programs, known as primacy , to individual states (see Figure 2 ). Section 1422 mandates that states seeking primacy adopt and implement UIC programs that meet all minimum federal requirements under Section 1421. For wells other than certain oil- and gas-related injection wells, states must adopt laws and regulations at least as stringent as EPA regulations and meet other statutory requirements to be granted primacy. EPA grants a state primacy through a federal rulemaking process for one or more classes of wells. If granted primacy for a class of wells, a state administers that UIC program, develops its own requirements, and allows well injection by state rule or by issuing permits. If a state's UIC plan has not been approved or the state has chosen not to assume program responsibility, SDWA requires that EPA directly implement the program in that state. UIC Well Classes Under SDWA authority, EPA has established six classes of underground injection wells based on similarity in the fluids injected. Construction, injection depth, design requirements, and operating techniques vary among well classes. Some wells are used to inject fluids into formations below USDWs, while others involve injection into or above USDWs. EPA regulations set out specific permitting and performance standards for each class of wells. In 2010, EPA issued the first federal rule specific to underground injection of CO 2 , Federal Requirements Under the Underground Control (UIC) Program for Carbon Dioxide (CO 2 ) Geological Sequestration (Class VI Rule). In the rule, the agency promulgated regulations for underground injection of CO 2 for long-term storage and established UIC Class VI, a new class of wells for geologic sequestration of CO 2 . Prior to the Class VI rule's effective date in January 2011, injection of CO 2 was permitted under Class II if used for EOR or Class V if the well was experimental (e.g., DOE-supported research wells). Table 1 lists the classes of UIC wells. EPA has delegated UIC program primacy for well Classes I-V to 32 states (see Figure 2 ). EPA has delegated primacy for all six well classes to one state, North Dakota. Seven states and two tribes have primacy for Class II wells only. Including those states, a total of 40 states have primacy for Class II. For Class VI, EPA has direct implementation authority in 49 states and for all territories. For Classes I, III, IV and V only, the agency has delegated primacy for two states. EPA shares UIC implementation responsibility with seven states and two Indian tribes and implements the UIC program for all classes in eight states. Additional states are pursuing Class VI primacy: EPA is reviewing Wyoming's application for Class VI primacy, and Louisiana is in a pre-application phase. As with regulations for other well classes, the Class VI rule allows states to apply for primacy for Class VI wells without applying for primacy for other well classes. Class VI Geologic Sequestration Wells Underground injection for the purpose of long-term geologic sequestration of CO 2 is subject to SDWA UIC regulations for Class VI wells. Class VI requirements may also apply to CO 2 injection for EOR using Class II wells when EPA or the delegated state determines that there is an increased risk to USDWs. Two Class VI wells, both in Illinois, are currently permitted in the United States. EPA issued these final permits in 2017 for two wells injecting CO 2 into a saline aquifer at the ADM ethanol plant in Illinois. In 2015, EPA issued a final Class VI permit for the FutureGen project, but the permit expired after the project was cancelled without any CO 2 injection taking place. No state has issued a permit for a Class VI well. EPA requires that state primacy for Class VI wells would be implemented under SDWA Section 1422. Unique Class VI Requirements When developing minimum federal requirements for Class VI wells, EPA generally built upon Class I hazardous waste requirements. The agency added new requirements to address the unique properties of CO 2 and geologic sequestration in the Class VI rule. In the preamble to the Class VI rule, EPA noted that "tailored requirements, modeled on the existing UIC regulatory framework, are necessary to manage the unique nature of CO 2 injection for geologic sequestration." EPA bases the regulation of CO 2 injection as a separate class of wells on several unique risk factors to USDWs: Â the large volumes of CO 2 expected to be injected through wells; the relative buoyancy of CO 2 in underground geologic formations; the mobility of CO 2 within subsurface formations; the corrosive properties of CO 2 in the presence of water that can effect well materials; and the potential presence of impurities in the injected CO 2 stream. Due to all of these properties, Class VI requirements establish a larger injection site "area of review" compared to requirements for other classes. The area of review for Class VI wells "includes the subsurface three-dimensional extent of the carbon dioxide plume, associated area of elevated pressure, and displaced fluids, as well as the surface area above that delineated region." The requirements also obligate well owners or operators to track, model, and predict CO 2 plume movement. The monitoring and post-injection site care requirements in the regulations are based on estimates that commercial-scale CO 2 injection projects are expected to operate between 30 and 60 years. Appendix C compares the major permitting requirements and technical standards for Class II wells related to oil and gas production, which are used for EOR, and Class VI wells for geologic sequestration of CO 2 . To assist states and owner operators with the permitting process, EPA has also issued 11 technical guidance documents on Class VI wells. These documents are not legally enforceable but provide additional information on site characterization, area of review, construction, reporting and recordkeeping, site closure, financial responsibility, and other permit elements. Class II Oil and Gas Related Wells Class II wells are used to inject fluids associated with oil and gas production, including wells injecting CO 2 for EOR. EOR wells are the most common type of Class II wells. As of 2018, there were approximately 178,000 permitted Class II wells, approximately 135,600 (76%) of which were recovery wells. Most of these wells are located in California, Texas, Kansas, Illinois, and Oklahoma. Approximately 20% of Class II wells are disposal wells and hydrocarbon storage wells. States may request primacy for Class II oil- and gas-related injection operations under SDWA Section 1422 or Section 1425. Section 1422 mandates that state programs meet EPA requirements promulgated under Section 1421 and prohibits underground injection that is not authorized by permit or rule. EPA regulations under Section 1421 specify requirements for siting, construction, operation, monitoring and testing, closure, corrective action, financial responsibility, and reporting and recordkeeping. Sixteen states and three territories have Class II primacy under Section 1422. Section 1425 allows states to administer their own Class II UIC programs using state rules in lieu of EPA regulations provided a state demonstrates that it has an effective program that prevents underground injection that endangers drinking water sources. To receive approval under Section 1425's optional demonstration provisions, a state program must include permitting, inspection, monitoring, and recordkeeping and reporting requirements. Twenty-four states and two tribes have Class II primacy under Section 1425. Most oil- and gas-producing states have primacy for Class II under this section. Overall, nearly 99% of EOR wells are located in states with primacy under Section 1425. For the 10 states without Class II primacy, the District of Columbia, and most tribes, EPA directly implements the Class II program, and federal regulations apply. While both Class II and Class VI wells involve injection of CO 2 into underground reservoirs, the purposes and regulations of these two classes are different. Class II wells inject primarily into oil or gas fields for the purposes of enhancing production from an underground oil and gas reservoir. In Class II wells, only some of the CO 2 stays in the reservoir during each recovery cycle, gradually increasing the total volume of CO 2 stored. In Class VI wells, all of the injected CO 2 is intended to remain in the reservoir for sequestration. CO 2 sequestration in Class VI wells generally involves higher injection pressures, larger expected fluid volumes, and different physical and chemical properties of the injection stream compared to Class II wells. Given these differences between the two well classes, EPA Class II regulations specify different requirements than Class VI regulations. Generally, EPA Class II requirements impose less comprehensive performance requirements and provide longer time periods between mandatory testing and reporting compared to EPA Class VI requirements. Unlike EPA Class VI requirements, EPA Class II requirements do not include providing seismicity information, continuous monitoring of the injection pressure and CO 2 stream, monitoring of the CO 2 plume and pressure front, or monitoring of groundwater quality throughout the lifetime of the project. EPA Class II requirements also do not impose post-injection site care or emergency and remedial response requirements, which are included in EPA Class VI requirements. Class II wells can be granted a permit or authorized by rule by either a primacy state or EPA, while Class VI wells cannot be authorized by rule. See Appendix C for more information on EPA Class II well requirements. Transition of Wells from Class II to Class VI Wells Class II EOR wells have a different primary purpose than Class VI wells and must transition to a Class VI permit under certain conditions. EPA has determined that "owners or operators of Class II wells that are injecting carbon dioxide for the primary purpose of long-term storage into an oil or gas reservoir must apply for and obtain a Class VI permit where there is an increased risk to USDWs compared to traditional Class II operations." EPA recognizes that there may be some CO 2 trapped in the subsurface at EOR operations. However, if the Class VI UIC program director (either EPA or the primacy state) has determined that there is no increased risk to USDWs, then these operations would continue to be permitted under the Class II requirements. To date, no Class II wells have been transitioned to Class VI. Other Federal Authorities Regulations promulgated under most other federal environmental statutes have generally not applied to underground injection or geologic sequestration of CO 2 . If the well owner or operator constructs, operates, and closes the injection well in accordance with a UIC Class II or Class VI permit, the injection and storage would typically not be subject to other federal air quality, waste management, or environmental response authorities and related liability. For example, a release of a hazardous substance in compliance with a UIC permit would be exempt as a "federally permitted release" from liability and reporting requirements of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Such federally permitted releases would also be exempt from emergency notification requirements of the Emergency Planning and Community Right-to-Know Act (EPCRA). During the development of the UIC Class VI final rule, some stakeholders in the CCS industry asked EPA for clarification on how hazardous waste requirements, established under the Resource Conservation and Recovery Act (RCRA), may apply to CO 2 streams that are geologically sequestered. In response, EPA promulgated a rule excluding CO 2 from RCRA's hazardous waste management requirements when injected into UIC Class VI wells. As a result, when geologically sequestered in compliance with a UIC Class VI well permit, CO 2 streams are not separately subject to RCRA requirements applicable to the management of hazardous waste. Certain federal regulations may apply to CCS processes or facilities that support CO 2 injection and sequestration, such as carbon capture and CO 2 transportation and compression. The regulatory frameworks of these activities are beyond the scope of this report. Clean Air Act Greenhouse Gas Reporting Program The Greenhouse Gas Reporting Program (GHGRP) established by EPA under the authority of the Clean Air Act, requires certain sources of GHGs to report emissions data. In 2010, EPA promulgated a rule to include injection and geologic sequestration of CO 2 in the GHGRP. In this rule, the agency determined that facilities that inject CO 2 for long-term sequestration and all other facilities that inject CO 2 underground fall within the GHGRP covered source categories. Therefore, reporting requirements apply to both Class VI wells and Class II wells that inject CO 2 . EPA's purpose for collecting this information is two-fold: to track CO 2 emissions and to quantify the amount of CO 2 being sequestered. Under the GHGRP Rule Subpart RR, facilities that inject a CO 2 stream for long-term containment (i.e., geologic sequestration) must develop and implement a monitoring, reporting, and verification plan. The purpose of this plan is to verify the amount of CO 2 sequestered and collect data on any CO 2 surface emissions from geologic sequestration facilities. Any facility holding a Class VI permit would be subject to Subpart RR and be required to report the mass of CO 2 that is received, injected into the subsurface, produced, emitted by surface leakage, emitted by leaks in equipment, and emitted by venting. Facilities must also report the mass of CO 2 sequestered in subsurface geologic formations. Subpart UU of the rule applies to Class II wellsâfor the injection of CO 2 for EOR and for small and experimental sequestration projects exempted under Subpart RR. Subpart UU does not require a monitoring, reporting, and verification plan and sets forth different requirements for monitoring and reporting. Issues for Congress If Congress were to address carbon storage through underground injection, there are a variety of policy issues Members may consider. Several policy issues relate to the current SDWA UIC regulatory framework and what elements of CO 2 injection are covered under the statute's purpose and approach. Congress may also wish to consider other issues that may have implications for CO 2 injection and storage policy, including current pathways of federal support for CCS and underground carbon storage, project cost, and stakeholder perspectives on CCS and fossil fuels. Scope of the SDWA UIC Regulatory Framework SDWA currently serves as the major federal authority for regulating injection of CO 2 for geologic sequestration and carbon storage in general. However, the major purpose of the act's UIC provisions is to prevent endangerment of public water supplies and sources from injection activities. In the preamble to the proposed Class VI Rule, EPA states, "While the SDWA provides EPA with the authority to develop regulations to protect USDWs from endangerment, it does not provide authority to develop regulations for all areas related to GS [geologic sequestration]." The agency identified specific policy areas related to geologic sequestration that are beyond the agency's authority, including (but not limited to) capture and transport of CO 2 , managing human health and environmental risks other than drinking water endangerment, determining property rights, and transfer of liability from one entity to another. The agency acknowledges the challenge of balancing SDWA goals with broader efforts to support geologic sequestration. In the preamble to the Class VI Rule, EPA noted that the rule "ensures protection of USDWs while also providing regulatory certainty to industry and permitting authorities and an increased understanding of GS through public participation and outreach." Potential Environmental Risks of Geologic Sequestration of CO2 Federal agencies, external analysts, and other stakeholders have expressed a variety of viewpoints on the potential risks associated with injection and geologic sequestration of CO 2 . EPA, the Interagency Task Force on Carbon Capture and Storage, and others have recognized that CO 2 injection and sequestration activities may convey risks to the environment and human health. Some of these risks involve potential endangerment of USDWs that would be covered by SDWA. Other potential impacts, however, are not covered by SDWA or the UIC implementing regulations. For groundwater-related risks, EPA has noted that expansion of CO 2 -EOR and associated CO 2 storage could increase the risk of endangerment to USDWs due to increased injection zone pressures and the large number of wells in oil and gas fields that could serve as leakage pathways. Injected CO 2 could also force brine from the target formation into USDWs, which could affect drinking water. To address potential releases or leakage that could endanger USDWs, in the Class VI rule, EPA included monitoring, reporting, and recordkeeping requirements specific to CO 2 injection. Class VI construction and testing requirements, which are generally more stringent than Class II requirements for EOR, are also intended to prevent USDW endangerment. Regarding other types of risk from improperly managed projects, EPA identified risks to air quality, human health, and ecosystems as potential concerns not addressed by SDWA authorities. In its 2010 report, the Task Force concluded that SDWA's limited application to only those groundwater formations that meet the specific statutory definition of USDWs may "require clarification to support actions to address or remedy ecological or non-drinking water human health impacts arising from the injection and sequestration of CO 2 ." The Task Force also stated that an accidental large release could result in risks to surface water, local ecology, and human health. (See text box Human Health and Environmental Considerations of CO 2 and Geologic Sequestration .) An additional concern with injection and sequestration of CO 2 is the increased potential for earthquakes associated with deep-well injection. Earthquakes induced by CO 2 injection could fracture the rocks in the reservoir or, more importantly, the caprock above the reservoir. Class VI well regulations require that information on earthquake-related history be included in the permit application and that owners or operators not exceed injection pressure that would induce seismicity or initiate fractures. NETL and other stakeholders offer other perspectives on potential health and environmental risks. Regarding the risks of CO 2 leakage, NETL outlines several case studies on leakage related to underground carbon storage in a 2019 report. The report states that use of EOR in the United States "has demonstrated that large volumes of gas can be stored safely underground and over long timeframes when the appropriate best-practices are implemented." According to the report, "Despite over 40 years of operating CO 2 EOR projects, leakage events have rarely been reported," although the authors also note that "there has been no official mechanism for reporting leaks of CO 2 until recently." Other stakeholders have also commented that, even given potential health and environmental risks, the benefits of CO 2 sequestration in reducing GHG emissions as part of climate change mitigation efforts outweigh such risks. Liability and Property Rights Issues In the Class VI rule, EPA acknowledged stakeholder interest in liability and long-term stewardship but noted that that the agency does not have the authority to determine property rights or transfer liability from one owner or operator to another. In its report, the Task Force also identified that "the existing Federal framework largely does not provide for a release or transfer of liability from the owner/operator to other persons" and noted that some stakeholders view these issues as a barrier to future CCS project deployment. Specific policy questions regarding property rights include who owns and controls the subsurface formations (known as the pore space) targeted for CO 2 sequestration, if and how such property can be transferred or aggregated, and how underground reservoirs that cross state and tribal boundaries should be regulated. State laws and contractual property arrangements, similar to those established for oil and gas development, may address some of these questions, but some analysts identify the need for more clarity. Issues of financial liability and long-term stewardship of injection sites and storage reservoirs also remain largely unresolved. Analysts have raised questions such as (1) who is responsible for the site and reservoir after the 50-year mandated post-injection site care period, (2) what is the role of the federal or state government in assisting site developers and operators with managing the risks associated with sequestration activities, and (3) whether the federal government should be involved in taking on some or all financial responsibility during the life-cycle of sequestration projects. Large-scale commercial geologic sequestration projects would likely require unique liability and stewardship structures that address issues such as the particular characteristics of CO 2 , the entire life-cycle of sequestration projectsâfrom site selection to periods beyond site closureâand the geologic time frame (hundreds or thousands of years) over which sequestration occurs. For more information on legal sequestration issues, see CRS Report RL34307, Legal Issues Associated with the Development of Carbon Dioxide Sequestration Technology , by Adam Vann and Paul W. Parfomak. Other Policy Considerations Research and Development EPA has stated that "a supporting regulatory framework for the future development and deployment of [carbon storage] technology can provide the regulatory certainty needed to foster industry adoption of CCS, which is crucial to supporting the goal of any climate change legislation." Even with the completion of several large-scale demonstration field projects, analysts recognize uncertainties regarding wide-spread commercial CCS operation in the United States. These technical issues include uncertainties in operations, such as how much CO 2 would be injected, CO 2 sources, availability of appropriate locations, and the exact constituents of CO 2 injection streams. A lack of existing infrastructure for CCS systemsâfrom capture technology to pipelines to transport CO 2 âmay also act as barriers to future CCS deployment. Congress has directly supported federal activities in both geologic sequestration of CO 2 and EOR through the EPAct in 2005 and EISA in 2007, directing DOE to carry out R&D activities to further technical knowledge and deployment of CCS. Several bills in the 116 th Congressâincluding H.R. 1166 / S. 383 , H.R. 3607 , and S. 1201 âwould continue or expand DOE's CCS programs, including carbon storage programs. Some of these bills would direct EPA to conduct CCS research and/or direct DOE to develop and implement R&D programs related to geologic sequestration methods, storage siting, and assessment of potential impacts. Provisions in some of these bills would also direct DOE to continue its partnership programs for large-scale sequestration demonstration projects. Other relevant provisions include provisions that would require actions from the Council on Environmental Quality, such as publishing guidance and submitting reports to Congress on CCS research and development. Project Cost The cost of constructing and operating a new CCS system or retrofitting an existing facility, such as a coal-fired power plant, with CCS is likely to play a major role in the future deployment of commercially viable sequestration projects. Costs for large-scale geologic sequestration or EOR include expenses directly related to injection and storage, as well as costs of investing in sufficient carbon capture and transportation infrastructure and maintaining ongoing facility operations. Regarding regulatory costs associated with geologic sequestration, in the preamble to the Class VI rule, EPA specified the agency's intention that the rule would not impede geologic sequestration: Should this rule somehow impede GS from happening, then the opportunity costs of not capturing with the benefits associated with GS could be attributed to this regulation; however the Agency has tried to develop a rule that balances risk with practicability, site specific flexibility and economic considerations and believes the probability of such impedance is low. Analysts expect that the costs of CCS, whether new system or retrofitting of an existing facility, are likely to total several billion dollars per project, which could act as a barrier to future CCS deployment without the continuation of subsidies. Recently, Public Service Company of New Mexico reportedly estimated that retrofitting a 500-megawatt coal-fired power plant with CCS technology could cost between $5 billion and $6 billion. The company reportedly stated that its evaluations showed that it would be more cost effective to switch to another source of energy (such as renewable energy) rather than continue to use coal with the addition of CCS. Examples of completed commercial-scale CCS operations and associated costs are limited, causing some uncertainty regarding future investments and the scale of project deployment in the coming decades. In a 2019 report, NETL indicated that "the potential costs of commercial-scale CCS are still not fully understood, particularly from a fully integrated (capture, transportation, and storage) perspective." Costs could vary greatly due to a variety of site-specific factors. The type of capture technology is the largest component of costs, possibly accounting for as much as 80% of the total. The variations in the geology of storage formations also make predicting future geologic sequestration costs particularly difficult. Projects that inject some or all the CO 2 for EOR (with incidental carbon storage) involve different cost implications and economic factors from projects injecting solely for permanent CO 2 sequestration. These factors could influence future deployment of these types of projects, as facility owners and operators may consider cost implications when deciding whether to invest in EOR or when deciding between investing projects for EOR or permanent geologic sequestration. EOR operations typically use the existing injection infrastructure in place from earlier oil and gas production activities. Thus, the well exploration and construction costs are "sunk costs." Unlike geologic sequestration projects, these expenses may not be included in total project cost calculations, resulting in comparatively lower costs for injecting and storing the CO 2 . In addition, for EOR projects, overall project costs could be influenced by revenue for the owner or operator from additional oil and gas production. EOR project costs may also be subject to variability and uncertainty, however. NETL notes that the price of oil and the cost and availability of CO 2 are key drivers in the economics of CO 2 EOR. Federal tax credits for carbon storage, available since 2009 for both EOR and geologic sequestration, may also play a role in underground injection and storage of CO 2 project costs and investment decisions . These credits are discussed later in this report. Public Acceptance and Participation In the preamble to the proposed Class VI rule, EPA noted that "GS of CO 2 is a new technology that is unfamiliar to most people, and maximizing the public's understanding of the technology can result in more meaningful public input and constructive participation as new GS projects are proposed and developed." EPA also stated that "the agency expects that there will be higher levels of public interest in GS projects than for other injection activities." In the Class VI rule, EPA adopted the existing UIC public participation requirements, which require permitting authorities to provide public notice of pending actions, hold public hearings if requested, solicit and respond to public comments, and involve a broad range of stakeholders. At least two cases involving Class VI permits have come before EPA's Environmental Appeals Board. The first case involved the permit for the FutureGen facility, which was never constructed. The second case involved ADM's Illinois facility, currently operating and permitted in Illinois. Public concerns centered on safety and environmental protection issues, including air quality, groundwater quality, and protection of endangered species. Local landowners claimed that the permits do not adequately address how the facility will ensure these protections in the event of leakage or well failure. They also raised concerns about property rights (including mineral rights), potential decreases in property value, and increased traffic associated with the facilities. Continued Use of Fossil Fuels In the EPAct in 2005 and EISA in 2007, Congress recognized connections between geologic sequestration of CO 2 and the continued use of fossil fuel as a major source of electricity in the United States. Consistent with Congress's directives, DOE's CCS research identifies that the purpose of its CCS research, technology development, and testing is "to benefit the existing and future fleet of fossil fuel power generating facilities by creating tools to increase our understanding of geologic reservoirs appropriate for CO 2 storage and the behavior of CO 2 in the subsurface." In the preamble to the proposed Class VI rule, EPA stated that, "the capture and storage of CO 2 would enable the continued use of coal in a manner that greatly reduces the associated CO 2 emissions while other safe and affordable energy sources are developed in the coming decades." Some stakeholders have argued for further research, development and deployment of CCS (when coupled with negative carbon technology, such as direct air capture) as a method for achieving the negative emissions trajectories modeled by the IPCC. Some of these stakeholders state that CCS is an appropriate transitional technology to reduce CO 2 emissions from electricity generation and other industrial sources while expanding the capacity of low or zero-carbon power sources, such as renewable energy. In contrast, other stakeholders have argued that CO 2 sequestration could create a disincentive to reduce fossil-fuel-based power plant emissions or shift to renewable energy sources. In particular, some stakeholders note that injecting CO 2 for EOR may actually increase net GHG emissions, as it produces additional oil and gas to be burned as fuel. CCS systems also require energy to compress, transport, and inject the CO 2 , which, if derived from fossil fuel combustion, could detract from the net GHG reduc tion benefits of sequestration. Carbon Storage Tax Credits Federal tax credits for carbon storage were first enacted in 2008 by the Energy Improvement and Extension Act ( P.L. 110-343 ). This act added Section 45Q to the Internal Revenue Code, which established tax credits for CO 2 storage through both EOR and geologic sequestration. For EOR, only the CO 2 that is used as tertiary injectant and remains in the reservoir qualifies for the tax credit. CO 2 recaptured or recycled does not qualify. The Bipartisan Budget Act of 2018 (BBA) amended Section 45Q to increase the amount of these tax credits from $22.66 to $50 per ton over time for sequestered CO 2 and from $12.83 to $35 per ton over time for CO 2 used in EOR. The BBA also removed a 75-million-ton cap on total qualified CO 2 captured or injected but required the relevant taxpayer to claim the credit over a 12-year period after operations begin. Additionally, eligible facilities must be operating or must begin construction before 2024. The U.S. Department of the Treasury is currently considering comments on proposed implementing regulations for the BBA tax credit provision and has not released a final rule. In response to the 2019 Internal Revenue Service notice requesting comments on carbon credits for future regulations and guidance, some oil and gas industry commenters expressed concerns with Treasury's proposed approach to measuring "secure geological storage" and other requirements, which they assert would impact their ability to plan and invest in CCS projects. In the meantime, the tax credit as authorized in the BBA is available to qualified entities. Treasury estimates that in FY2019, the credit will reduce federal income tax revenue by $70 million. Over the FY2020-FY2029 budget window, Treasury estimates that the tax credit will reduce federal income tax revenue by a total of $2.3 billion. As of May 2019, the amount of stored carbon oxide claimed for 45Q credits since 2011 totaled 62,740,171 tons. In legislation pending in the 116 th Congress, H.R. 5156 would extend the deadline for the start of construction of a qualified facility to January 1, 2025. S. 2263 would revise the requirements for the secure geologic storage of carbon oxide for EOR and sequestration. Recent CCS Legislation Table 2 , below, lists legislation introduced in the 116 th Congress that includes provisions relating to geologic sequestration of CO 2 (as of date of report publication). Legislation in the 116 th Congress has focused on research and development of CCS, including carbon storage through EOR and geologic sequestration, and adjustments to the 45Q carbon storage tax credit. Appendix A. Estimates of U.S. Storage Capacity forÂ CO 2 Appendix B. Large Scale Injection and Geologic Sequestration of CO 2 Projects in the United States Appendix C. Comparison of Class II and Class VI Wells


Introduction Fully autonomous vehicles, which would carry out many or all of their functions without the intervention of a driver, may someday bring sweeping social and economic changes and "lead to breakthrough gains in transportation safety." Motor vehicle crashes caused an estimated 36,560 fatalities in 2018; a study by the National Highway Traffic Safety Administration (NHTSA) has shown that 94% of crashes are due to human errors. Legislation that would encourage development and testing of autonomous vehicles has faced controversy in Congress. In the 115 th Congress, the House of Representatives passed an autonomous vehicle bill, H.R. 3388 , by voice vote in September 2017. The Senate Committee on Commerce, Science, and Transportation reported a different bill, S. 1885 , in November 2017, but after some Senators raised concerns about the preemption of state laws and the possibility of large numbers of vehicles being exempted from some Federal Motor Vehicle Safety Standards, the Senate bill did not reach the floor. No further action was taken on either bill before the 115 th Congress adjourned. Although some Members of Congress remain interested in autonomous vehicles, no legislative proposals have become law. Several fatal accidents involving autonomous vehicles raised new questions about how federal and state governments should regulate vehicle testing and the introduction of new technologies into vehicles offered for sale. A pedestrian was killed in Arizona by an autonomous vehicle operated by Uber on March 18, 2018, and three Tesla drivers died when they failed to respond to hazards not recognized by the vehicles. These accidents suggest that the challenge of producing fully autonomous vehicles that can operate safely on public roads may be greater than developers had envisioned, a new outlook voiced by several executives, including the Ford Motor Co. CEO. However, with the authorization of federal highway and public transportation programs set to expire at the end of FY2020, a surface transportation reauthorization bill could become a focus of efforts to also enact autonomous vehicle legislation. Advances in Vehicle Technology While fully autonomous vehicles may lie well in the future, a range of new technologies is already improving vehicle performance and safety while bringing automation to vehicular functions once performed only by the driver. The technologies involved are very different from the predominantly mechanical, driver-controlled technology of the 1960s, when the first federal vehicle safety laws were enacted. These new features automate lighting and braking, connect the car and driver to the Global Positioning System (GPS) and smartphones, and keep the vehicle in the correct lane. Three forces are driving these innovations: technological advances enabled by new materials and more powerful, compact electronics; consumer demand for telecommunications connectivity and new types of vehicle ownership and ridesharing; and regulatory mandates pertaining to emissions, fuel efficiency, and safety. Manufacturers are combining these innovations to produce vehicles with higher levels of automation. Vehicles do not fall neatly into the categories of "automated" or "nonautomated," because all new motor vehicles have some element of automation. The Society of Automotive Engineers International (SAE), an international standards-setting organization, has developed six categories of vehicle automationâranging from a human driver doing everything to fully autonomous systems performing all the tasks once performed by a driver. This classification system ( Table 1 ) has been adopted by the U.S. Department of Transportation (DOT) to foster standardized nomenclature to aid clarity and consistency in discussions about vehicle automation and safety. Vehicles sold today are in levels 1 and 2 of SAE's automation rating system. Although some experts forecast market-ready autonomous vehicles at level 3 will be available in a few years, deployment of fully autonomous vehicles in all parts of the country at level 5 appears to be more distant, except perhaps within closed systems that allow fully autonomous vehicles to operate without encountering other types of vehicles. Testing and development of autonomous vehicles continue in many states and cities. Technologies that could guide an autonomous vehicle ( Figure 1 ) include a wide variety of electronic sensors that would determine the distance between the vehicle and obstacles; park the vehicle; use GPS, inertial navigation, and a system of built-in maps to guide the vehicle's direction and location; and employ cameras that provide 360-degree views around the vehicle. To successfully navigate roadways, an autonomous vehicle's computers, sensors and cameras will need to accomplish four tasks that a human driver undertakes automatically: detect objects in the vehicle's path; classify those objects as to their likely makeup (e.g., plastic bag in the wind, a pedestrian or a moving bicycle); predict the likely path of the object; and plan an appropriate response. Most autonomous vehicles use dedicated short-range communication (DSRC) to monitor road conditions, congestion, crashes, and possible rerouting. As 5G wireless communications infrastructure is installed more widely, DSRC may evolve and become integrated with it, enabling vehicles to offer greater interoperability, bandwidth, and cybersecurity. Some versions of these autonomous vehicle technologies, such as GPS and rear-facing cameras, are being offered on vehicles currently on the market, while manufacturers are studying how to add others to safely transport passengers without drivers. Manufacturers of conventional vehicles, such as General Motors and Honda, are competing in this space with autonomous vehicle "developers" such as Alphabet's Waymo. In addition, automakers are aligning themselves with new partners that have experience with ride-sharing and artificial intelligence: Ford and Volkswagen have announced that they expect to use autonomous vehicle technology in a new ride-sharing service in Pittsburgh, PA, as early as 2021; GM acquired Cruise Automation, a company that is developing self-driving technology for Level 4 and 5 vehicles. GM has also invested $500 million in the Lyft ride-sharing service; Honda, after breaking off talks about partnering with Waymo, purchased a stake in GM's Cruise Automation; Volvo and Daimler have announced partnerships with ride-sharing service Uber; and BMW partnered with the Mobileye division of Intel, a semiconductor manufacturer, to design autonomous vehicle software. Cybersecurity and Data Privacy As vehicle technologies advance, the security of data collected by vehicle computers and the protection of on-board systems against intrusion are becoming more prominent concerns. Many of the sensors and automated components providing functions now handled by the driver will generate large amounts of data about the vehicle, its location at precise moments in time, driver behavior, and vehicle performance. The systems that allow vehicles to communicate with each other, with roadside infrastructure, and with manufacturers seeking to update software will also offer portals for possible unauthorized access to vehicle systems and the data generated by them. Protecting autonomous vehicles from hackers is of paramount concern to federal and state governments, manufacturers, and service providers. A well-publicized hacking of a conventional vehicle by professionals demonstrated to the public that such disruptions can occur. Hackers could use more than a dozen portals to enter even a conventional vehicle's electronic systems ( Figure 2 ), including seemingly innocuous entry points such as the airbag, the lighting system, and the tire pressure monitoring system (TPMS). Requirements that increasingly automated vehicles accept remote software updates, so that owners do not need to take action each time software is revised, are in part a response to concerns that security weaknesses be rectified as quickly as possible. To address these concerns, motor vehicle manufacturers established the Automotive Information Sharing and Analysis Center (Auto-ISAC), which released a set of cybersecurity principles in 2016. DOT's autonomous vehicle policies designate Auto-ISAC as a central clearinghouse for manufacturers to share reports of cybersecurity incidents, threats, and violations with others in the vehicle industry. Aside from hackers, many legitimate entities would like to access vehicle data, including vehicle and component manufacturers, the suppliers providing the technology and sensors, the vehicle owner and occupants, urban planners, insurance companies, law enforcement, and first responders (in case of an accident). Issues pertaining to vehicle data collection include vehicle testing crash data (how is it stored and who gets to access it); data ownership (who owns most of the data collected by vehicle software and computers); and consumer privacy (transparency for consumers and owner access to data). At present, no laws preclude manufacturers and software providers from reselling data about individual vehicles and drivers to third parties. Pathways to Autonomous Vehicle Deployment Abroad Autonomous vehicles are being developed and tested in many countries, including those that produce most of the world's motor vehicles. Several analyses have evaluated the factors that are contributing to the advancement of autonomous vehicles in various countries: Innovation . Benchmarks in this area include the number and engagement of domestic automakers and technology developers working on automation, the partnerships they forge with academic and related businesses, the prevalence of ride-sharing services, and autonomous vehicle patents issued. V ehicle infrastructure . Autonomous vehicles will need new types of infrastructure support and maintenance, including advanced telecommunications links and near-perfect pavement and signage markings. Planning and implementing these highway improvements may enable autonomous vehicles to be fully functional sooner. In addition, many test vehicles are currently powered by electricity, so the availability of refueling stations could be a factor in their acceptance. Wo rkforce training. The increased reliance on autonomous vehicle technologies may require different workforce skills. Many traditional mechanical parts may disappear, especially if autonomous vehicles operate entirely on battery power, while the arrangement and function of dashboards and seating may be reinvented. Components suppliers that are already addressing this new product demand and reorienting their workforces will assist in the transition to autonomous vehicles. G overnment laws and regulations that encourage development and testing . Fully autonomous vehicles may not have standard features of today's cars, such as steering wheels and brake pedals, as there will not be a driver. By law or regulation, motor vehicles built today are required to have many of these features. Some governments are taking a lead by modifying vehicle requirements for purposes of pilot programs and tests. Permanent changes in standards will most likely be necessary if autonomous vehicle technologies are to be commercialized. L evel of consumer acceptance . Markets are more likely to embrace autonomous vehicles if many residents in cities see autonomous vehicles on the road, a high level of technology is in use (including internet access and mobile broadband), and ride-hailing services are more widely used. Several surveys have been conducted analyzing many of these factors. For example, a 2018 Harvard University report highlights plans in China, South Korea, Japan, and the United States to "seize the benefits" of autonomous vehicles. In a report on innovation policies in four Asian countries (China, Japan, South Korea, and Singapore), the United Nations Economic and Social Commission for Asia and the Pacific ranked Singapore first in autonomous vehicle readiness because of its policies and new laws governing their deployment and its high consumer acceptance. The report also notes that South Korea's K-City facility is "intended to be the world's largest testbed for self-driving cars." A more detailed comparison of factors affecting autonomous vehicle development and deployment has been conducted by KPMG International, which has developed an index to measure how 25 countries are guiding autonomous vehicles ( Table 2 ). The Netherlands ranked first overall in the KPMG report, where it was cited as "an example of how to ready a country for AVs by performing strongly in many areas , " as well as first in infrastructure. Singapore came in first on policy and legislation because it has a single government entity overseeing autonomous vehicle regulations, it is funding autonomous vehicle pilots, and it has enacted a national standard to promote safe deployment. Contributing to its rank was a World Economic Forum (WEF) report that ranked it first among 139 countries in having an effective national legislature and efficient resolution of legal disputes. Singapore also scored first place on the consumer acceptance metric, primarily because its extensive autonomous testing is being conducted throughout the island nation, thereby familiarizing residents with autonomous passenger vehicles and buses. Two other major auto-producing countriesâGermany and Japanâfall just below the United States on technology and innovation, according to KPMG, while Japan ranks higher on autonomous vehicle infrastructure ( Table 3 ). Issues in Federal Safety Regulation Vehicles operating on public roads are subject to dual regulation by the federal government and the states in which they are registered and driven. Traditionally, NHTSA, within DOT, has regulated auto safety, while states have licensed automobile drivers, established traffic regulations, and regulated automobile insurance. Proponents of autonomous vehicles note that lengthy revisions to current vehicle safety regulations could impede innovation, as the rules could be obsolete by the time they take effect. In 2016, the Obama Administration issued the first report on federal regulations affecting autonomous vehicles. Since then, DOT has issued two follow-up reports and has said it anticipates issuing annual updates to its regulatory guidance. In addition, the Federal Communications Commission (FCC) is reconsidering the allocation of electromagnetic spectrum currently reserved for motor vehicle communications, and its decisions may affect how autonomous vehicles evolve. Obama Administration Policy Direction DOT's 2016 report proposed federal and state regulatory policies in these areas: A set of guidelines outlining best practices for autonomous vehicle design, testing, and deployment. DOT identified 15 practices and procedures that it expected manufacturers, suppliers, and service providers (such as ridesharing companies) to follow in testing autonomous vehicles, including data recording, privacy, crashworthiness, and object and event detection and response. These reports, called Safety Assessment Letters, would be voluntary, but the report noted that "they may be made mandatory through a future rulemaking." A m odel s tate p olicy that identifies where new autonomous vehicle-related issues fit in the current federal and state regulatory structures. The model state policy, developed by NHTSA in concert with the American Association of Motor Vehicle Administrators and private-sector organizations, suggests state roles and procedures, including administrative issues (designating a lead state agency for autonomous vehicle testing), an application process for manufacturers that want to test vehicles on state roads, coordination with local law enforcement agencies, changes to vehicle registration and titling, and regulation of motor vehicle liability and insurance. A streamlined review process to issue DOT regulatory interpretations on autonomous vehicle questions within 60 days and on regulatory exemptions within six months. Identification of new tools and regulatory structures for NHTSA that could build its expertise in new vehicle technologies, expand its ability to regulate autonomous vehicle safety, and increase speed of its rulemakings. Two new tools could be expansion of existing exemption authority and premarket testing to assure that autonomous vehicles will be safe. Some of the new regulatory options cited would require new statutory authority, while others could be instituted administratively. The report noted that "DOT does not intend to advocate or oppose any of the tools.â¦ [I]t intends â¦ to solicit input and analysis regarding those potential options from interested parties." Trump Administration Policy Guidelines and Proposed SafetyÂ Rules The two follow-up reports issued by the Trump Administration describe a more limited federal regulatory role in overseeing autonomous passenger vehicle deployment, while also broadening the scope of DOT oversight by addressing the impact of autonomous technology on commercial trucks, public transit, rail, and ports and ships. The policies described in these reports replace those recommended by the Obama Administration in several ways, including the following: Encouraging integration of automation across all transportation modes , instead of just passenger vehicles. The October 2018 report Automated Vehicles 3.0 outlines how each of DOT's agencies will address autonomous vehicle safety within its purview. Establishing six automation principles that will be applied to DOT's role in overseeing passenger cars, trucks, commercial buses, and other types of vehicles. These include giving priority to safety; remaining technology-neutral; modernizing regulations; encouraging a consistent federal and state regulatory environment; providing guidance, research, and best practices to government and industry partners; and protecting consumers' ability to choose conventional as well as autonomous vehicles. Reiterating the traditional roles of federal and state governments in regulating motor vehicles and motorists, respectively. The reports cite best practices that states should consider implementing, such as minimum requirements for autonomous vehicle test drivers, and discuss how DOT can provide states with technical assistance. Recommending voluntary action in lieu of regulation. This could include suggesting that manufacturers and developers of autonomous driving systems issue and make public voluntary safety self-assessments to demonstrate transparency and increase understanding of the new technologies and industry development of "voluntary technical standards" to "advance the integration of automation technologies into the transportation system." The NHTSA Voluntary Safety Self-Assessment web page lists 17 companies that have filed self-assessment reports, including three major automakers. To provide a perspective, 64 companies have been issued autonomous vehicle testing permits by the State of California alone. Accelerating NHTSA decisions on requests for exemptions from federal safety standards for autonomous vehicle testing. Promoting development of voluntary technical standards by other organizations, such as the Society of Automotive Engineers, the government's National Institute of Standards and Technology, and the International Organization for Standardization. DOT has indicated that it wants to revise regulations pertinent to autonomous vehicles, such as redefining the terms "driver" and "operator" to indicate that a human being does not always have to be in control of a motor vehicle. It also said it plans to require changes in standards for the inspection, repair, and maintenance of federally regulated commercial trucks and buses. Along these lines, NHTSA issued a Notice of Proposed Rulemaking in May 2019, requesting comments on testing and verifying how autonomous vehicle technologies may comply with existing federal safety standards. National Transportation Safety Board Investigation and Recommendations On November 19, 2019, the National Transportation Safety Board (NTSB) issued its report on the probable cause of a 2018 fatality involving an autonomous vehicle in Tempe, AZ. In that accident, a pedestrian was fatally injured by a test vehicle operated by Uber Technologies with an operator in the driver's seat. The NTSB investigation determined that the probable cause of the crash "was the failure of the vehicle operator to monitor the driving environment and the operation of the ADS [automated driving system] because she was visually distracted throughout the trip by her personal cell phone." Though the vehicle detected the pedestrian 5.6 seconds before the crash, the NTSB reported that "it never accurately classified her as a pedestrian or predicted her path." Beyond the immediate cause of this accident, NTSB reported that an "inadequate safety culture" at Uber and deficiencies in state and federal regulation contributed to the circumstances that led to the fatal crash. Among the findings were the following: Uber's internal safety risk-assessment procedures and oversight of the operator were inadequate, and its disabling of the vehicle's forward collision warning and automatic emergency braking systems increased risks. The Arizona Department of Transportation provided insufficient oversight of autonomous vehicle testing in the state. NHTSA provides insufficient guidance to developers and manufacturers on how they should achieve safety goals, has not established a process for evaluating developers' safety self-assessment reports, and does not require such reports to be submitted, leaving their filing as voluntary. NTSB recommended that Uber, the Arizona Department of Transportation, and NHTSA take specific steps to address the issues it identified. It also recommended that the American Association of Motor Vehicle Administrators inform all states about the circumstances of the Tempe crash, encouraging them to require and evaluate applications by developers before granting testing permits. Connected Vehicles and Spectrum Allocation Federal regulation of the spectrum used in vehicle communications may affect how automation proceeds. Autonomous vehicles, whose artificial intelligence and technology are generally self-contained in each vehicle, are part of a larger category of connected vehicles and infrastructure. Federal, state, and industry research and testing of vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications has been under way since the 1990s. Together, these two sets of technologies, known as V2X, are expected to reduce the number of accidents by improving detection of oncoming vehicles, providing warnings to drivers, and establishing communications infrastructure along roadways that would prevent many vehicles from leaving the road and striking pedestrians. These technologies fall within the broad category of intelligent transportation systems, which have received strong support from Congress due to their potential to improve traffic flow and safety. For vehicles to communicate wirelessly, they use radio frequencies, or spectrum, which are regulated by the Federal Communications Commission (FCC). In 1999, the FCC allocated the 5.9 gigahertz (GHz) band solely for motor vehicle safety purposes for vehicles using DSRC. Over the past two decades, industry and government agencies have collaborated to develop, test, and deploy DSRC technologies. States have invested in DSRC-based improvements, and this technology is operating in dozens of states and cities. As industry has continued to explore vehicle automation, an alternative, cellular-based technology has recently emerged, known as C-V2X. In December 2019, the FCC proposed rules that would reallocate the lower 45 MHz of the 5.9 GHz band for unlicensed use (e.g., Wi-Fi), and allocate the remaining 30 MHz for transportation and vehicle-related use. Of the 30 MHz, the FCC proposed to grant C-V2X exclusive use of 20 MHz of the segment. It is seeking comment on whether the remaining 10 MHz should remain dedicated to DSRC or be dedicated to C-V2X. The FCC commissioners noted that DSRC has evolved slowly and has not been widely deployed, and the rules are intended to ensure the spectrum supports its highest and best use. This decision has competitive implications for the automotive, electronics, and telecommunications industries, and may affect the availability of safety technologies and the path toward vehicle automation. DOT has called for retaining the entire 5.9 GHz band for exclusive transportation use. Figure 3 shows that these two technologies facilitate somewhat different types of vehicle and infrastructure communications. In light of their different characteristics, the European Commission has approved DSRC use for direct V2V and V2I communications, while endorsing cellular-based technology for vehicle access to the cloud and remote infrastructure. Industry groups in the United States took varying positions in the FCC proceedings. DSRC advocates argued that this technology has been proven by years of testing and is already deployed in many areas. They generally supported retaining the 5.9 GHz band for exclusive use for DSRC. C-V2X supporters contended that its cellular-based solution is aligned with international telecommunications standards for 5G technologies and should be allowed to use the 5.9 GHz band alongside DSRC. A group of technology companies, including device makers, argued that additional spectrum is needed to accommodate the increasing number of interconnected devices, and that the 5.9GHz band can safely be shared among transportation and non-transportation uses. Congressional Action During the 115 th Congress, committees in the House of Representatives and the Senate held numerous hearings in 2017 on the technology of autonomous vehicles and possible federal issues that could result from their deployment. Initially, bipartisan consensus existed on major issues: H.R. 3388 , the SELF DRIVE Act, was reported unanimously by the House Committee on Energy and Commerce, and on September 6, 2017, the House of Representatives passed it without amendment by voice vote. A similar bipartisan initiative began in the Senate. Prior to markup in the Committee on Commerce, Science, and Transportation, the then-chairman and ranking member issued a set of principles they viewed as central to new legislation: prioritize safety , acknowledging that federal standards will eventually be as important for self-driving vehicles as they are for conventional vehicles; promote innovation and address the incompatibility of old regulations written before the advent of self-driving vehicles; remain technology - neutral , not favoring one business model over another; reinforce separate but complementary federal and state regulatory roles ; strengthen cybersecurity so that manufacturers address potential vulnerabilities before occupant safety is compromised; and educate the public through government and industry efforts so that the differences between conventional and self-driving vehicles are understood. Legislation slightly different from the House-passed bill emerged: S. 1885 , the AV START Act, was reported by the Committee on Commerce, Science, and Transportation on November 28, 2017. It was not scheduled for a floor vote prior to adjournment in December 2018 because of unresolved concerns raised by several Senators. To address some of those concerns, a committee staff draft bill that would have revised S. 1885 was circulated in December 2018 that could form the basis of future legislation. The House and Senate bills addressed concerns about state action replacing some federal regulation, while also empowering NHTSA to take unique regulatory actions to ensure safety and encouraging innovation in autonomous vehicles. The bills retained the current arrangement of states controlling most driver-related functions and the federal government being responsible for vehicle safety. The House and Senate bills included the following major provisions. Where the December 2018 Commerce Committee staff draft proposed significant changes, they are noted in this analysis. P reemption of state laws . H.R. 3388 would have barred states from regulating the design, construction, or performance of highly autonomous vehicles, automated driving systems, or their components unless those laws are identical to federal law. The House-passed bill reiterated that vehicle registration, driver licensing, driving education, insurance, law enforcement, and crash investigations should remain under state jurisdiction as long as state laws and regulations do not restrict autonomous-vehicle development. H.R. 3388 provided that nothing in the preemption section should prohibit states from enforcing their laws and regulations on the sale and repair of motor vehicles. S. 1885 would also have preempted states from adopting laws, regulations, and standards that would regulate many aspects of autonomous vehicles, but would have omitted some of the specific powers reserved to the states under the House-passed bill. States would not have been required to issue drivers licenses for autonomous-vehicle operations, but states that chose to issue such licenses would not have been allowed to discriminate based on a disability. The bill provided that preemption would end when NHTSA establishes standards covering these vehicles. The Senate staff draft sought to clarify that state and local governments would not lose their traditional authority over traffic laws. It also would have added provisions that state common law and statutory liability would be unaffected by preemption, and would have limited use of arbitration in death or bodily injury cases until new federal safety standards are in effect. Exemption authority . Both the House and Senate bills would have expanded DOT's ability to issue exemptions from existing safety standards to encourage autonomous-vehicle testing on public roads. To qualify for an autonomous-vehicle exemption, a manufacturer would have had to show that the safety level of the vehicle equaled or exceeded the safety level of each standard for which an exemption was sought. Current law limits exemptions to 2,500 vehicles per manufacturer per year. The House-passed bill would have phased in increases over four years of up to 100,000 vehicles per manufacturer per year; the Senate bill would have permitted up to 80,000 in a similar phase-in. H.R. 3388 provided constraints on the issuance of exemptions from crashworthiness and occupant protection standards; S. 1885 did not address those two issues. DOT would have been directed to establish a publicly available and searchable database of motor vehicles that have been granted an exemption. Crashes of exempted vehicles would have had to be reported to DOT. The Senate bill would not have required the establishment of a database of exempted vehicles, and reporting of exempt vehicle crashes would not have been required. The Senate staff draft added a provision to ensure that vehicles exempted from federal standards would have been required to nonetheless maintain the same level of overall safety, occupant protection, and crash avoidance as a traditional vehicle. A DOT review of vehicle exemptions would have been required annually. The draft capped exemptions at no more than five years. New NHTSA safety rules. The House bill would have required NHTSA to issue a new regulation requiring developers and manufacturers to submit a "safety assessment certification" explaining how safety is being addressed in their autonomous vehicles. The Senate bill included a similar provision requiring a "safety evaluation report," and would have delineated nine areas for inclusion in the reports, including system safety, data recording, cybersecurity risks, and methods of informing the operator about whether the vehicle technology is functioning properly. While manufacturers and developers would be required to submit reports, the legislation did not mandate that NHTSA establish an assessment protocol to ensure that minimum risk conditions are met. The Senate staff draft would have clarified the process by which federal motor vehicle safety standards would be updated to accommodate new vehicle technologies, providing additional time for new rulemaking. Within six months of enactment, DOT would have been required to develop and publicize a plan for its rulemaking priorities for the safe deployment of autonomous vehicles. To address concerns that autonomous vehicles might not recognize certain potential hazardsâincluding the presence of bicyclists, pedestrians, and animalsâand hence possibly introduce new vulnerabilities to motor vehicle travel, the Senate staff draft would have clarified that manufacturers must describe how they are addressing the ability of their autonomous vehicles to detect, classify, and respond to these and other road users. Manufacturers and developers would include this analysis in their safety evaluation reports. Cybersecurity. The House-passed bill provided that no highly autonomous vehicle or vehicle with "partial driving automation" could be sold domestically unless a cybersecurity plan had been developed by the automaker. Such plans would have to have been developed within six months of enactment and would include a written policy on mitigation of cyberattacks, unauthorized intrusions, and malicious vehicle control commands; a point of contact at the automaker with cybersecurity responsibilities; a process for limiting access to autonomous driving systems; and the manufacturer's plans for employee training and for maintenance of the policies. The Senate bill would have required written cybersecurity plans to be issued, including a process for identifying and protecting vehicle control systems, detection, and response to cybersecurity incidents, and methods for exchanging cybersecurity information. A cybersecurity point of contact at the manufacturer or vehicle developer would have had to be named. Unlike the House-passed bill, S. 1885 would have directed DOT to create incentives so that vehicle developers would share information about vulnerabilities, and would have specified that all federal research on cybersecurity risks should be coordinated with DOT. In addition, S. 1885 would have established a Highly Automated Vehicle Data Access Advisory Committee to provide Congress with recommendations on cybersecurity issues. Federal agencies would have been prohibited from issuing regulations pertaining to the access or ownership of data stored in autonomous vehicles until the advisory committee's report was submitted. The staff draft would have added several cybersecurity provisions, including an additional study by the National Institute of Standards and Technology that would recommend ways vehicles can be protected from cybersecurity incidents. Privacy. Before selling autonomous vehicles, manufacturers would have been required by the House-passed bill to develop written privacy plans concerning the collection and storage of data generated by the vehicles, as well as a method of conveying that information to vehicle owners and occupants. However, a manufacturer would have been allowed to exclude processes from its privacy policy that encrypt or make anonymous the sources of data. The Federal Trade Commission would have been tasked with developing a report for Congress on a number of vehicle privacy issues. Although S. 1885 would not have explicitly required privacy plans by developers and manufacturers, it would have required NHTSA to establish an online, searchable motor vehicle privacy database that would include a description of the types of information, including personally identifiable information (PII), that are collected about individuals during operation of a motor vehicle. This database would have covered all types of vehiclesânot just autonomous vehiclesâand would have included the privacy policies of manufacturers. The database would also have included an explanation about how PII would be collected, retained, and destroyed when no longer relevant. The Senate staff draft would have added new passenger motor vehicle privacy protections. Research and advisory panels. Both bills would have established several new advisory bodies to conduct further research on autonomous vehicles and advise DOT on possible new vehicle standards. H.R. 3388 would have established a NHTSA advisory group with a broad cross-section of members to advise on mobility access for senior citizens and the disabled; cybersecurity; labor, employment, environmental, and privacy issues; and testing and information sharing among manufacturers. S. 1885 would have established other panels, including a Highly Automated Vehicles Technical Committee to advise DOT on rulemaking policy and vehicle safety; a working group comprising industry and consumer groups to identify marketing strategies and educational outreach to consumers; and a committee of transportation and environmental experts to evaluate the impact of autonomous vehicles on transportation infrastructure, mobility, the environment, and fuel consumption. Separately, DOT would have been required to study ways in which autonomous vehicles and parts could be produced domestically, with recommendations on how to incentivize U.S. manufacturing. The Senate staff draft would have consolidated some of the advisory committees in S. 1885 into a Highly Automated Vehicle Advisory Council with diverse stakeholder representation, and mandated to report on mobility for the disabled, senior citizens and populations underserved by public transportation; cybersecurity; employment and environmental issues; and privacy and data sharing. No similar comprehensive autonomous vehicle legislation has been introduced in the 116 th Congress, although discussions on a bicameral bill have been ongoing. In addition, the Senate Committee on Environment and Public Works has reported America's Transportation Infrastructure Act of 2019, S. 2302 , which includes several provisions in Subtitle D addressing the possible impact of autonomous vehicles on highway infrastructure. It would establish a grant program to modernize the U.S. charging and fueling infrastructure so that it would be responsive to technology advancements, including autonomous vehicles. The legislation would also require research on ways in which roadway infrastructure should be improved for autonomous vehicles. State Concerns State and local rules and regulations may affect how autonomous vehicles are tested and deployed. The National Governors Association (NGA) has noted that state governments have a role with respect to vehicle and pedestrian safety, privacy, cybersecurity, and linkage with advanced communications networks. While supporting technology innovations in transportation, a recent NGA report notes that "the existing regulatory structure and related incentives have not kept pace with the new technology" and that "recent accidents have raised concerns about the safety of drivers, pedestrians and other road users in the period during which autonomous and non-autonomous vehicles share the road." NGA has joined with other state and local government organizations to call for modifications in forthcoming autonomous vehicle legislation, including clarity that states and local governments not only can enforce existing laws governing operation of motor vehicles on public roads, but also originate new statutes and regulations; requiring submission of more detailed automaker and developer reports to DOT on the safety of their technologies, so that states and cities can be assured that autonomous vehicle testing is being conducted in a safe manner; differentiation between limited vehicle testing and the commercial deployment of large numbers of autonomous vehicles through an expanded exemptions process; and expansion of plans for consumer education about "safe use and interaction" with respect to autonomous vehicles. According to the National Conference of State Legislatures (NCSL), at least 41 states and the District of Columbia considered legislation related to autonomous vehicles between 2013 and October 2019; in that time, 29 states and the District of Columbia enacted legislation, governors in 11 states issued executive orders, and 5 states issued both an executive order and enacted legislation. ( Figure 4 ). Of the states that have enacted laws in 2017, 2018, and 2019 pertaining to autonomous vehicles, NCSL reports that the largest number of states have passed laws that clarify certain types of commercial activity, such as how closely autonomous vehicles can follow each other when they are coordinated, as in truck platooning. According to NCSL, no recent state laws have been enacted dealing with cybersecurity or vehicle inspection reports. NCSL has organized and categorized the types of state legislation ( Table 4 ). For a more thorough description of the legislation passed in 2017, 2018, and 2019, the NCSL Table of Enacted State Legislation provides more detail. Implications for Highway Infrastructure Deployment of fully autonomous vehicles will require not only a suite of new technologies, but also changes to the highway infrastructure on which those vehicles will operate. Autonomous vehicles being tested today rely on clear pavement markings and legible signage to stay in their lanes and navigate through traffic. Major highways as well as side roads in urban and rural settings will need to accommodate autonomous vehicles in addition to a large fleet of conventional vehicles with human drivers. In this transition period to more autonomous vehiclesâwhich many anticipate will last several decades âthe Federal Highway Administration (FHWA) is expected to play a significant role through its administration of the Manual on Uniform Traffic Control Devices (MUTCD), which sets standards for all traffic control devices, including signs, intersection signals, and road markings. For example, overhead signage on Interstate Highways contains white lettering on a green background in all 50 statesâeasily recognizable to any U.S. driverâdue to MUTCD standards. FHWA is in the process of updating the 2009 MUTCD to address issues specific to autonomous vehicle technologies. However, state compliance with MUTCD is voluntary, and not all states uniformly apply all standards. Audi reportedly announced in 2018 that it would not make its new Level 3 autonomous vehicle technology, called Traffic Jam Pilot, available in the United States because of "laws that change from one state to the next, insurance requirements, and things like lane lines and road signs that look different in different regions." Other automakers have made similar complaints about U.S. roads. In the near term, improvement and better maintenance of pavement markings, signage and intersection design may be the most helpful steps that federal and state transportation officials can take. Despite national standards based on MUTCD, not all states maintain their highway markings at a level that would be useful to guide autonomous vehicles. Inadequate road maintenance may affect the pace of autonomous vehicle deployment. Some 21% of major U.S. roads are in poor condition, and a road with many potholes or temporary pavement repairs may also lack continuous lane markings. Many minor roads, which are generally the responsibility of county or municipal governments, may lack road edge lines as well as center lines, potentially making it difficult for autonomous vehicles to position themselves correctly. Dirt and gravel roads may pose particular challenges for autonomous vehicles, as they generally have no pavement markings and cameras may be unable to detect potholes or edges in low-visibility conditions. Closely tied to the need for clearer road markings and signage will be ways in which federal and state transportation agencies develop a standardized method to communicate information to vehicles and motorists about construction, road accidents, detours, and other changes to road environments. Many of the perceived benefits of autonomous vehiclesâreduced vehicle fatalities, congestion mitigation, and pollution reductionâmay depend on the ability of vehicles to exchange information with surrounding infrastructure. The Transportation Research Board (TRB) has been evaluating how states should begin now to plan and develop the types of connected vehicle infrastructure that will be necessary for full autonomous vehicle deployment. TRB's research is also focused on how cash-strapped transportation agencies can identify the large investments that will in turn be necessary to implement connectivity on top of regular maintenance of highways, bridges, and other traditional infrastructure. Other options to facilitate autonomous vehicle travel may include designation of special highway corridors that would include all V2X systems necessary for safe autonomous vehicle operation; three European countries have agreed to build such a corridor. Over a longer time line, the importance of highway markings may fade as automakers and developers find new ways for autonomous vehicles to navigate, including greater use of guardrails and roadside barriers, sensors, and three-dimensional maps. If highly detailed mapping is deemed to be one replacement for visual cues such as lane markings, then transportation agencies and automakers may need to develop an open standard so that all vehicles will understand the mapping technology. V2X communications through DSRC and cellular may evolve to provide a mechanism for new types of vehicle guidance. Appendix. Image of Nuro Robot, R2X