

 
The Renewable Fuel Standard (RFS): Waiver 
Authority and Modification of Volumes 
Updated August 22, 2022 
Congressional Research Service 
https://crsreports.congress.gov 
R44045 
 
  
 
The Renewable Fuel Standard (RFS): Waiver Authority and Modification of Volumes 
 
Summary 
The Clean Air Act requires that transportation fuels contain a minimum volume of renewable 
fuel. This Renewable Fuel Standard (RFS) was established by the Energy Policy Act of 2005 
(EPAct05; P.L. 109-58) and amended by the Energy Independence and Security Act of 2007 
(EISA; P.L. 110-140). The RFS includes scheduled volume mandates that grow each year 
(starting with 9 billion gallons in 2008 and ascending to 36 billion gallons in 2022). The U.S. 
Environmental Protection Agency (EPA), which is responsible for administering the RFS, 
determines the annual volume after 2022. Within the overall RFS, there are submandates for 
advanced biofuels, including cellulosic biofuel and biomass-based diesel. 
EPA has the authority to waive the RFS volume requirements, in whole or in part, if certain 
conditions outlined in statute prevail. More specifically, the statute includes a general waiver 
authority and waivers for two types of advanced biofuel: cellulosic biofuel and biomass-based 
diesel. The statute requires EPA to announce the upcoming year’s standards by November 30 of 
the previous year, except for biomass-based diesel, which is to be announced 14 months before 
the year for which the applicable volume is to apply. Further, the final section of the waiver 
provision—which some refer to as the “reset” section—requires a permanent modification of 
applicable volumes of the RFS if certain conditions are met (i.e., if the applicable volumes are 
reduced by at least 20% for two consecutive years or by at least 50% for a single year). The 
statute allows the modification of the applicable volumes to take place starting in 2016.  
In several instances, EPA has used, has proposed to use, or has been petitioned to use its waiver 
authority when implementing the RFS. In July 2022, EPA reported in its final rule for the 2020, 
2021, and 2022 RFS volume requirements that it was using the cellulosic waiver authority along 
with the “reset” waiver authority to reduce the applicable volume requirements for total 
renewable fuel, advanced biofuel, and cellulosic biofuel. EPA’s use of the cellulosic biofuel 
waiver authority is not new. EPA has repeatedly issued a waiver, reducing the volume required for 
cellulosic biofuel. For various reasons (e.g., technology issues, financial support, policy 
uncertainty), the U.S. cellulosic biofuel industry has been unable, by a wide margin, to produce 
the volume amounts identified in statute.  
EPA has not previously used its authority to “reset” the RFS. In the 2020, 2021, and 2022 final 
RFS program rule, EPA reports it is using the cellulosic waiver authority along with the “reset” 
waiver authority to reduce the applicable volumes for 2020, 2021, and 2022 for total renewable 
fuel, advanced biofuel, and cellulosic biofuel. In addition, EPA reports that the “reset” was 
triggered for cellulosic biofuel by the 2010 annual standard set for the program, for advanced 
biofuel by the 2014 and 2015 annual standards set for the program, and for total renewable fuel 
by the 2018 and 2019 annual standards set for the program.  
Come 2023, both the waiver authority and the reset will become moot points for future 
implementation of the RFS program. The statute gives the EPA Administrator the authority to 
determine the volume amounts—based on a review of implementation of the program thus far, an 
analysis of criteria identified in statute, and other stipulations—for all fuel categories starting in 
2023.
Congressional Research Service 
 link to page 4  link to page 4  link to page 5  link to page 6  link to page 7  link to page 7  link to page 8  link to page 8  link to page 9  link to page 9  link to page 10  link to page 10  link to page 5  link to page 6  link to page 11 The Renewable Fuel Standard (RFS): Waiver Authority and Modification of Volumes 
 
Contents 
Introduction ..................................................................................................................................... 1 
RFS Requirements ........................................................................................................................... 1 
RFS Annual Volume Announcement Deadlines .............................................................................. 2 
Current RFS Requirements.............................................................................................................. 3 
RFS Waiver Provisions .................................................................................................................... 4 
General Waiver .......................................................................................................................... 4 
Cellulosic Biofuel Waiver ......................................................................................................... 5 
Biomass-Based Diesel Waiver .................................................................................................. 5 
Modification of Applicable Volumes ........................................................................................ 6 
RFS Waiver Authority Use .............................................................................................................. 6 
RFS Waiver Impacts ........................................................................................................................ 7 
Impacts of RFS Modification of Applicable Volumes ..................................................................... 8 
 
Figures 
Figure 1. Scheduled Renewable Fuel Standard (RFS) Mandates Under EISA ............................... 2 
  
Tables 
Table 1. EISA and EPA RFS Requirements (2014-2022) ................................................................ 3 
  
Contacts 
Author Information .......................................................................................................................... 8 
 
Congressional Research Service 
 link to page 5 The Renewable Fuel Standard (RFS): Waiver Authority and Modification of Volumes 
 
Introduction 
The Renewable Fuel Standard (RFS) requires that the nation’s transportation fuel supply contain 
renewable fuels.1 This mandate—established in the Energy Policy Act of 2005 (EPAct05; P.L. 
109-58) and expanded in the Energy Independence and Security Act of 2007 (EISA; P.L. 110-
140)—requires the use of renewable fuel, although it does not explicitly require the production of 
that fuel. Obligated parties, such as refiners or importers of gasoline or diesel fuel, are responsible 
for complying with the RFS requirements. The U.S. Environmental Protection Agency (EPA) 
administers the mandate, which is an amendment to Clean Air Act (CAA) provisions governing 
the regulation of fuels.2 The statutory renewable fuel volume increases annually until 2022, with 
EPA determining the volume after 2022 within certain limitations. In general, EPA has the 
authority to waive the RFS requirements, in whole or in part, if certain conditions outlined in 
statute prevail. 
The RFS is a complex and highly technical policy initiative. It deals with multiple sectors of the 
economy and requires the use of some advanced renewable fuel production technologies that 
have yet to reach maturity. The RFS also incorporates thresholds for greenhouse gas emission 
reduction. This complexity is heightened by multiple stakeholders with differing perspectives on 
what the RFS should accomplish, how it should be implemented, and whether it should exist, 
which leads to debate about the RFS and its future. Congressional debate about the RFS is 
expected to continue with special attention to how EPA administers the program.3 As Congress 
continues its oversight of the RFS, it may be useful to understand the RFS waiver authority 
granted to EPA. This report discusses the waiver provisions of the RFS, including the 
modification-of-applicable-volumes (“reset”) section. 
RFS Requirements 
EPAct05 established a renewable fuel program (i.e., the RFS) requiring that transportation fuel 
sold or introduced into commerce in the United States, on an annual average basis, contain a 
specified amount of renewable fuel. The RFS mandate, as amended by EISA, calls for the 
consumption of 9 billion gallons of total renewable fuel in 2008, ascending to 36 billion gallons 
in 2022, with EPA determining the annual volume after 2022. The statute identifies four 
categories of renewable fuels that are to be used to meet the mandate. These four categories can 
be aggregated into two major categories: unspecified biofuel (mainly cornstarch ethanol) and 
advanced biofuel (e.g., cellulosic biofuel, biomass-based diesel, and other advanced biofuels), 
shown in Figure 1.4 Over time, the growth in the RFS transitions from biofuels that, in practice, 
are made mostly from food and feed crops to biofuels made from nonfood and nonfeed crops. For 
instance, in 2022, the statute requires that advanced biofuels constitute close to 60% of the 36 
billion gallon mandate and unspecified biofuels constitute about 40%.  
                                                 
1 For more information on the Renewable Fuel Standard (RFS) and related issues, see CRS Report R43325, The 
Renewable Fuel Standard (RFS): An Overview, by Kelsi Bracmort. 
2 P.L. 109-58 (Title XV, Subtitle A, Section 1501) established the RFS under Clean Air Act Section 211(o); 42 U.S.C. 
§7545(o). P.L. 110-140 expanded the RFS, including the requirement of larger annual volumes and the addition of 
greenhouse gas accounting requirements. 
3 Legislation has been introduced in the 117th Congress that would modify or repeal the RFS. For example, see H.R. 
190, H.R. 1113, H.R. 5701, S. 218, and S. 2385.  
4 The unspecified biofuel volume requirement equates to the difference between the total renewable fuel category and 
the advanced biofuel category. 
Congressional Research Service  
 
1 

The Renewable Fuel Standard (RFS): Waiver Authority and Modification of Volumes 
 
Figure 1. Scheduled Renewable Fuel Standard (RFS) Mandates Under EISA 
 
Sources: Congressional Research Service (CRS) using mandates in the Energy Independence and Security Act of 
2007 (EISA; P.L. 110-140). 
RFS Annual Volume Announcement Deadlines 
Congress gave the EPA Administrator an annual deadline to determine and publish the renewable 
fuel obligations (i.e., final volume requirements). The EPA Administrator is required to announce 
the renewable fuel obligations (typically referred to as “set the standards”) by November 30 of 
the preceding year (e.g., under statute, the 2022 standard is required to be finalized by November 
30, 2021).5 For biomass-based diesel, the statute specifies volumes for four years (2009-2012) 
and requires EPA to announce the remaining annual biomass-based diesel standards “14 months 
before the first year for which such applicable volume will apply” (e.g., the 2022 biomass-based 
diesel standard is required to be finalized by November 2020).6 The requirement that EPA 
announce the standard 14 months prior is scheduled to apply to the other renewable fuel 
categories for calendar years 2023 and onward. 
                                                 
5 42 U.S.C. §7545 (o)(3)(B)(i). 
6 42 U.S.C. §7545 (o)(2)(B)(ii).  
Congressional Research Service  
 
2 
 link to page 6  link to page 6  link to page 6  link to page 6 The Renewable Fuel Standard (RFS): Waiver Authority and Modification of Volumes 
 
Current RFS Requirements 
EPA issued the final 2020, 2021, and 2022 standards (and the 2021 standard for biomass-based 
diesel) in June 2022.7 The RFS statutory requirements and the EPA requirements for 2014 
through 2022 are provided in Table 1.  
Table 1. EISA and EPA RFS Requirements (2014-2022) 
(in billions of gallons) 
Unspecified 
Total 
Biofuel / Cap on 
Advanced Biofuel 
Renewable 
Conventional 
(cellulosic biofuel 
Year 
Fuel 
Biofuel 
component)a 
2014 Statutory 
18.15 
14.40 
 3.75 (1.750) 
2014 EPA Final 
16.28 
13.61 
 2.67 (0.033) 
2015 Statutory 
20.50 
15.00 
5.50 (3.000) 
2015 EPA Final 
16.93b 
14.05 
2.88 (0.123) 
2016 Statutory 
 22.25 
15.00 
7.25 (4.250) 
2016 EPA Final 
18.11b 
14.50 
3.61 (0.230) 
2017 Statutory 
24.00 
15.00 
9.00 (5.500) 
2017 EPA Final 
19.28 
15.00 
4.28 (0.311) 
2018 Statutory 
26.00 
15.00 
11.00 (7.000) 
2018 EPA Final 
19.29 
15.00 
4.29 (0.288) 
2019 Statutory 
28.00 
15.00 
13.00 (8.500) 
2019 EPA Final 
19.92 
15.00 
4.92 (0.418) 
2020 Statutory 
30.00 
15.00 
15.00 (10.50) 
2020 EPA Final 
17.13 
12.5 
4.63 (0.510) 
2021 Statutory 
33.00 
15.00 
18.00 (13.50) 
2021 EPA Final 
18.84 
13.79 
5.05 (0.560) 
2022 Statutory 
36.00 
15.00 
21.00 (16.00) 
2022 EPA Final 
20.63 
15.00 
5.63 (0.630) 
2023 and beyond 
To Be Determined by the EPA Administratorc 
Sources: EISA (P.L. 110-140); 42 U.S.C. §7545(o); Final rules are available at U.S. Environmental Protection 
Agency, Regulations and Volume Standards for Renewable Fuel Standards, July 25, 2022, https://www.epa.gov/
renewable-fuel-standard-program/regulations-and-volume-standards-renewable-fuel-standards. 
Notes: All volumes are ethanol equivalent. Ethanol equivalent is the amount of fuel needed to give the same 
amount of energy as one gallon of ethanol.  
a.  Advanced biofuels can include cellulosic biofuel, biomass-based diesel, biogas, butanol, and others. Advanced 
biofuel is defined as renewable fuel, other than cornstarch ethanol, that has lifecycle greenhouse gas 
emissions that are at least 50% lower than the emissions from comparable petroleum products.  
b.  The D.C. Circuit Court vacated EPA’s 2016 total renewable fuel volume requirement and remanded the 
2015 final rule to EPA for reconsideration. Americans for Clean Energy v. EPA, No. 16-1005, 2017 U.S. App. 
                                                 
7 U.S. Environmental Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal 
Register 39600, July 1, 2022.  
Congressional Research Service  
 
3 
The Renewable Fuel Standard (RFS): Waiver Authority and Modification of Volumes 
 
LEXIS 13692, at *4-5 (D.C. Cir. July 28, 2017). EPA addresses the court remand of the 2014-2016 final rule 
by adding a supplemental volume obligation of 250 mil ion gallons for 2022 (EPA stated that it intends to 
establish an additional supplemental volume of 250 mil ion gallons for 2023 as well). U.S. Environmental 
Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal Register 39601, 
July 1, 2022. 
c.  The EPA Administrator is to consult with the Secretaries of Energy and Agriculture and take into account 
an analysis of certain factors to determine the volume amounts. 42 U.S.C. §7545(o)(2)(B)(i ). 
RFS Waiver Provisions 
The statute for the RFS contains a waiver section with a set of waiver provisions.8 The provisions 
describe three separate waivers—a general waiver, a cellulosic biofuel waiver, and a biomass-
based diesel waiver—that the EPA Administrator may use to waive, with certain stipulations for 
certain waivers, the volume of renewable fuel mandated by statute. The waivers referred to in this 
report should not be confused with small refinery exemptions.9 Additionally, there is a provision 
for the modification of applicable volumes (i.e., a “reset”) that the EPA Administrator may use. 
The waivers and the modification of applicable volumes are described in further detail in the 
following sections of this report. 
General Waiver 
The RFS statute gives the EPA Administrator the authority to waive the RFS requirements, in 
whole or in part, “by reducing the national quantity of renewable fuel required” if  
  implementation of the requirement would severely harm the economy or 
environment of a state, a region, or the United States, or 
  domestic renewable fuel supply is inadequate to meet the mandate.10  
The Administrator may issue the general waiver at his or her discretion or if petitioned by a state 
or any person subject to the RFS requirements (e.g., refiners and importers). Prior to making a 
decision, the Administrator is required to consult with the Secretary of Agriculture and Secretary 
of Energy and to allow for public notice and the opportunity for comment. In those instances in 
which the Administrator receives a petition for a waiver, the Administrator has 90 days after 
receipt of the petition to approve or disapprove it.11 If a general waiver is issued, it expires after 
one year, unless the Administrator renews the waiver.12  
                                                 
8 42 U.S.C. §7545(o)(7). 
9 Small refiners may petition the EPA Administrator for an exemption from the RFS mandate if they can prove 
compliance would subject them to disproportionate economic hardship. For more information on small refinery 
exemptions, see 42 U.S.C. §7545(o)(9) or CRS Report R46244, The Renewable Fuel Standard (RFS): Frequently 
Asked Questions About Small Refinery Exemptions (SREs), by Kelsi Bracmort. 
10 42 U.S.C. §7545(o)(7)(A). 
11 Information regarding petitions to waive the RFS requirements is available at the EPA Requests for Volume 
Requirement Waiver under the Renewable Fuel Standard Program website, https://www.epa.gov/renewable-fuel-
standard-program/requests-volume-requirement-waiver-under-renewable-fuel-standard.  
12 42 U.S.C. §7545(o)(7)(C). 
Congressional Research Service  
 
4 
The Renewable Fuel Standard (RFS): Waiver Authority and Modification of Volumes 
 
Cellulosic Biofuel Waiver 
The RFS statute obligates the EPA Administrator to reduce the cellulosic biofuel mandate when 
the projected production capacity for a given year is less than the volume required in the statute.13 
The law does not require the EPA Administrator to consult with the Secretary of Agriculture or 
the Secretary of Energy when issuing a cellulosic biofuel waiver, or to give public notice and 
opportunity for comment. However, the Administrator is to use the projected volume estimate for 
cellulosic biofuel that the U.S. Energy Information Administration (EIA) is required to provide to 
EPA.14 The EPA Administrator is to set the new required amount at the “projected available 
volume during that calendar year” by November 30 of the preceding year. Should the 
Administrator reduce the cellulosic biofuel volume, the Administrator also may reduce the 
volumes of advanced biofuel and total renewable fuel by the same or lesser volume. When the 
Administrator issues a cellulosic biofuel waiver, the Administrator must offer cellulosic biofuel 
waiver credits for obligated parties to purchase for that compliance year in lieu of using actual 
cellulosic biofuel.15 In prior waiver determinations, EPA has provided opportunity for public 
comment.16 
Biomass-Based Diesel Waiver 
The RFS statutory provisions give the EPA Administrator authority to reduce the amount of 
biomass-based diesel required for up to 60 days if the Administrator determines that there are 
significant market circumstances (including feedstock disruptions) “that would make the price of 
biomass-based diesel fuel increase significantly.”17 If these market circumstances continue past 
the initial 60-day period, the Administrator may issue another waiver for an additional 60 days. 
The Administrator is to consult with the Secretaries of Energy and Agriculture prior to issuing 
such a waiver. If the Administrator issues a biomass-based diesel waiver, the Administrator also 
may reduce the volumes of advanced biofuel and renewable fuel by the same or lesser volume. As 
of July 2022, EPA has not used the biomass-based diesel waiver authority. 
                                                 
13 42 U.S.C. §7545(o)(7)(D). 
14 42 U.S.C. §7545(o)(3)(A). 
15 EPA reports that “[t]hese credits can then be used by obligated parties to comply with the cellulosic biofuel volume 
obligation in lieu of RINs [Renewable Identification Numbers] generated with the production of the cellulosic biofuel. 
Cellulosic biofuel waiver credits are for obligated parties who do not acquire sufficient RINs for their cellulosic biofuel 
RVO [Renewable Volume Obligation] in a given compliance year.” U.S. Environmental Protection Agency, What Is 
the Purpose of a Cellulosic Biofuel Waiver Credit? https://www.epa.gov/fuels-registration-reporting-and-compliance-
help/what-purpose-cellulosic-biofuel-waiver-credit. The formula to calculate the price of these credits is in statute. For 
more information on cellulosic waiver credits, see U.S. Environmental Protection Agency, Cellulosic Waiver Credits 
under the Renewable Fuel Standard Program, April 7, 2020, https://www.epa.gov/renewable-fuel-standard-program/
cellulosic-waiver-credits-under-renewable-fuel-standard-program. For more information on cellulosic biofuels and the 
RFS, see CRS Report R41106, The Renewable Fuel Standard (RFS): Cellulosic Biofuels, by Kelsi Bracmort. 
16 For example, see U.S. Environmental Protection Agency, Renewable Fuel Standard (RFS) Program: RFS Annual 
Rules Response to Comments, EPA-420-R-22-009, June 2022, pp 7-8. Additionally, when conducting its cellulosic 
biofuel volume assessment for the coming year, EPA has consulted with EIA and industry. For example, for the 2014 
cellulosic biofuel volume assessment, EPA reports it “spoke with representatives of each company to discuss cellulosic 
biofuel target production levels for 2014” and that “[t]hroughout this process EPA has been in contact with EIA to 
discuss relevant information.” U.S. Environmental Protection Agency, “2014 Standards for the Renewable Fuel 
Standard Program; Proposed Rule,” 78 Federal Register 71739, November 29, 2013. 
17 42 U.S.C. §7545(o)(7)(E).  
Congressional Research Service  
 
5 
The Renewable Fuel Standard (RFS): Waiver Authority and Modification of Volumes 
 
Modification of Applicable Volumes 
The last provision of the waiver section is the modification of applicable volumes provision, 
referred to by some as the “reset” provision for the RFS.18 This provision requires that the EPA 
Administrator modify the applicable volumes—for each fuel specified in the tables in the 
statute—of the RFS in future years if certain conditions are met. This “reset” authority is for 
applicable volumes starting in 2016 through 2022, and is to be used after the conditions are met 
and not retroactively. Specifically, it provides that, starting in 2016, the EPA Administrator shall 
modify the applicable volumes of the RFS for subsequent years if the Administrator waives the 
renewable fuel mandate, the advanced biofuel mandate, the cellulosic biofuel mandate, or the 
biomass-based diesel mandate by at least 20% for two consecutive years or by at least 50% for a 
single year. This reset section does not state what the modified amount must be. Rather, it 
requires that the Administrator determine the applicable volumes—in coordination with the 
Secretaries of Energy and Agriculture—based on a review of program implementation thus far 
and an analysis of certain factors (e.g., the impact of the production and use of renewable fuels on 
the environment).19 This reset provision does not apply to other calendar years—years after the 
calendar years specified in the statutory tables (e.g., 2023 and beyond for total renewable fuel). 
RFS Waiver Authority Use 
Since 2010, EPA has repeatedly used its cellulosic biofuel waiver authority to reduce the 
cellulosic biofuel volume required, and, since 2014, to also reduce both the advanced biofuel and 
total renewable fuel volume required.20 In June 2022, EPA announced that it was using the 
cellulosic waiver authority along with the reset authority to reduce the applicable volumes for the 
various fuel categories for 2020, 2021, and 2022.21 The Administrator has not issued a biomass-
based diesel waiver.  
To date, EPA has exercised the general waiver authority once to reduce the total renewable fuel 
volumes for 2014, 2015, and 2016, which the U.S. Court of Appeals for the D.C. Circuit 
subsequently vacated after concluding that EPA’s interpretation of “inadequate domestic supply” 
was not a permissible one.22 In that rule, EPA had interpreted the general waiver provision as 
allowing the agency to reduce all or any of the four renewable fuel volume requirements (i.e., 
total renewable fuel, advanced biofuels, biomass-based diesel fuel, or cellulosic biofuel) in whole 
or in part.23 In notices denying petitions for waivers, EPA has taken the position that any waiver 
must be nationwide in scope (i.e., reduce the statutory volumes nationwide).24 However, EPA has 
not codified this position in its regulations and no court has reviewed this interpretation. The 
general waiver authority has not been fully exercised; thus, it is not clear if only the total 
                                                 
18 42 U.S.C. §7545(o)(7)(F). 
19 The Administrator is directed to promulgate a rule that modifies the applicable volumes in compliance with 42 
U.S.C. §7545(o)(2)(B)(ii). 
20 A list of volume reductions from 2010 to the present is available in Table 1 of CRS Report R43325, The Renewable 
Fuel Standard (RFS): An Overview, by Kelsi Bracmort.  
21 U.S. Environmental Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal 
Register 39602, July 1, 2022. 
22 Americans for Clean Energy v. EPA, 864 F.3d 691, 710-13 (D.C. Cir. 2017). 
23 80 Federal Register 77420, 77435 (Dec. 14, 2015). The rule was subsequently vacated by Americans for Clean 
Energy v. EPA. 864 F.3d 691, 710-13 (D.C. Cir. 2017). 
24 See, e.g., 73 Federal Register 47168, 47172 (Aug. 13, 2008); 77 Federal Register 70752, 70756 (Nov. 27, 2012). 
Congressional Research Service  
 
6 
The Renewable Fuel Standard (RFS): Waiver Authority and Modification of Volumes 
 
renewable fuel category can be reduced or if any of the renewable fuel categories (e.g., advanced 
biofuel) can be reduced. 
RFS Waiver Impacts 
Waiver authority is intended, in part, to assist EPA with implementation of the RFS.25 One of 
EPA’s program tasks is to use the waiver authority, when required, to determine the annual final 
standard, and to announce that final standard by the statutory deadline. The challenge of 
projecting advanced biofuel production, pressure from some stakeholders, and other factors may 
have contributed to past delays (during the 2012-2015 and 2021-2022 timeframes) in issuing final 
standards under the waiver authority.26 Such delays could lead to difficulty for obligated parties 
who have to demonstrate program compliance and for renewable fuel producers who are 
interested in producing the required fuel. For 2016 through 2020, EPA has generally issued the 
final rule according to the statutory schedule.27 
Three stakeholders generally have had distinct views about the impacts of the waiver authority: 
the advanced biofuel industry, the conventional biofuel industry, and the petroleum industry. 
Some advanced biofuel advocates assert that issuing waivers, in conjunction with other factors, 
could weaken confidence in renewable fuel markets and the chosen technologies, specifically 
cellulosic biofuel.28 Advanced biofuel, particularly cellulosic biofuels, have not been produced at 
the levels called for in the statutory provisions by relatively large margins. Some conventional 
biofuel advocates have not always agreed with EPA’s proposals to use the waiver authority to 
reduce conventional biofuel volumes.29 Conventional biofuel production has remained in line 
with what the statutory provisions require. Some in the petroleum industry assert that the waiver 
authority can be used as an option to address the “blend wall,” or, the maximum ethanol limit that 
would serve to avoid causing damage to many engines, fuel systems, and fueling infrastructure of 
vehicles.30 
While perspectives about EPA’s use of the waiver authority vary among stakeholders, the waivers 
have provided EPA with the flexibility to establish volume requirements that have been attained.  
                                                 
25 EPA reports that “... Congress also recognized that under certain circumstances it would be appropriate for EPA to 
set volume requirements different from the statutory volume targets and thus provided waiver provisions in CAA 
section 211(o)(7).” U.S. Environmental Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS Annual 
Rules,” 87 Federal Register 39606, July 1, 2022. 
26 For a list of final rule release dates for the RFS, see Table 1 in CRS Report R43325, The Renewable Fuel Standard 
(RFS): An Overview, by Kelsi Bracmort. For an explanation of some of the challenges with cellulosic biofuel 
projection, see CRS Report R41106, The Renewable Fuel Standard (RFS): Cellulosic Biofuels, by Kelsi Bracmort.  
27 EPA retroactively reduced the 2020 standard in the final rule for 2020, 2021, and 2022. However, EPA issued the 
original 2020 final rule within a month of the November 30 statutory deadline. U.S. Environmental Protection Agency, 
Renewable Fuel Standard Program: Standards for 2020 and Biomass-Based Diesel Volume for 2021 and Other 
Changes, February 6, 2020. 
28 Advanced Ethanol Council, “33 Advanced Biofuel Companies Ask President Obama to Reconsider the Proposed 
RFS Rule for 2014,” press release, May 16, 2014; Advanced Ethanol Council, “AEC, BIO Joint Letter to White House 
over Proposed 2014 RFS Volumetric Blending Requirements,” October 29, 2013. 
29 Erin Voegele, “Biofuel Groups Testify in Support of a Strong RFS,” Biodiesel Magazine, January 4, 2022. 
30 American Petroleum Institute, “Court Decision on EPA RFS Waiver Underscores Need for Legislative RFS 
Reform,” press release, July 28, 2017. 
Congressional Research Service  
 
7 
The Renewable Fuel Standard (RFS): Waiver Authority and Modification of Volumes 
 
Impacts of RFS Modification of 
Applicable Volumes 
In the final rule for 2020, 2021, and 2022, EPA reports the “reset” provision (i.e., the 
modification-of-applicable-volumes provision of the RFS) has been triggered for three of the four 
renewable fuel categories identified in statute.31 EPA reports the “reset” was triggered for 
cellulosic biofuel volumes by the 2010 annual standard, for advanced biofuel volumes by the 
2014 and 2015 annual standards, and for total renewable fuel volumes by the 2018 and 2019 
annual standards. The 2020, 2021, and 2022 final rule is the first time that EPA has used the 
“reset” authority. EPA reports it is using the “reset” authority, along with the cellulose waiver 
authority, to reduce the applicable volumes for 2020, 2021, and 2022 for total renewable fuel, 
advanced biofuel, and cellulosic biofuel. Come 2023, the “reset” authority will no longer be 
relevant, as the EPA Administrator is to set the statutory requirements in the first instance for 
calendar years 2023 onward based on certain statutory criteria.32  
 
Author Information 
 
Kelsi Bracmort 
   
Specialist in Natural Resources and Energy Policy 
    
 
 
Disclaimer 
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan 
shared staff to congressional committees and Members of Congress. It operates solely at the behest of and 
under the direction of Congress. Information in a CRS Report should not be relied upon for purposes other 
than public understanding of information that has been provided by CRS to Members of Congress in 
connection with CRS’s institutional role. CRS Reports, as a work of the United States Government, are not 
subject to copyright protection in the United States. Any CRS Report may be reproduced and distributed in 
its entirety without permission from CRS. However, as a CRS Report may include copyrighted images or 
material from a third party, you may need to obtain the permission of the copyright holder if you wish to 
copy or otherwise use copyrighted material. 
 
                                                 
31 U.S. Environmental Protection Agency, “Renewable Fuel Standard (RFS) Program: RFS Annual Rules,” 87 Federal 
Register 39606, July 1, 2022. 
32 42 U.S.C. 7545(o)(2)(B)(ii). Other calendar years refers to those years for which there is no applicable volume 
specified in a table in statute for the RFS (e.g., 2013 for biomass-based diesel and 2023 for total renewable fuel). 
Congressional Research Service  
R44045 · VERSION 29 · UPDATED 
8