Title 13. California Air Resources  Board 
Notice  of Public  Comment  Period on  Proposed  Amendments  to 
the Heavy -Duty  Engine and Vehicle  Omnibus  Regulation 
The Executive  Officer (EO) of the California Air Resources Board  (CARB  or Board)  is 
proposing to consider  the adoption  of amendments to the Heavy- Duty  (HD) Engine and 
Vehicle Omnibus (Omnibus)  regulation under  the authority granted  by the Board  in 
Resolution 23-15, wherein the Board  delegated to the EO the power to adopt,  amend,  and 
revoke  emission standards,  test procedures , compliance test procedures,  and compliance  
flexibilities for new on-road motor v ehicles that the Board  previously  reserved to itself  in 
Board  Resolution 78-10. 
Written  comments  on the proposed regulatory  amendments must  be received by 
September  18, 2023, in order  to be considered by the EO. A public  hearing is not currently 
scheduled;  however,  you may request  the EO to conduct  a public  hearing.  The process  for 
requesting a public  hearing is explained in the Written  Comment Period  and Submittal  of 
Comments  section  of this notice,  below.  If a request  for a public  hearing is received  by 
September  3, 2023, the public  hearing will be conducted by the EO. The time,  date,  and 
place  of the hearing will be provided in a separate notice.  
Written Comment Period and Submittal of Comments  
In accordance  with the Administrative  Procedure Act, interested members  of the public  may 
present  comments  in writing  by postal  mail or by electronic  submittal.  A public  hearing is 
currently not scheduled.  The public  comment period for this regulatory actio n will begin on 
August  4, 2023. To be considered by the EO, written  comments  must be submitted  by 
September 18, 2023. Comments  submitted outside that comment period are considered 
untimely.  CARB  may,  but is not required to, respond to untimely  comments,  including those 
raising significant environmental  issues.  Comments  submitted  must be addressed to one of 
the following:  
Postal  mail: Clerks’  Office, California Air Resources Board  
1001 I Street,  Sacramento,  California 95814  
Electronic submittal : https://www.arb.ca.gov/lispub/comm/bclist.php 
Any interested  person  may request  a public  hearing pursuant  to section  11346.8 of the 
California Government Code,  no later than 15 days before the close  of the written  comment 
period.  A public  hearing will be scheduled if any interested person,  or their duly authorized 
representative,  requests such a hearing in writing  by September  3, 2023. The request  for a 
hearing may be submitted in the same  manner  as written  comments.  2 Please note that under  the California P ublic  Records Act (Gov. Code,  § 7920.000 et seq.),  
your written  and oral comments,  attachments,  and associated contact information (e.g., your 
address,  phone,  email, etc.) become  part of the public  record  and can be released to the 
public  upon request.  
Additionally, the EO requests but does not require that persons who submit  written  
comments  to the EO reference  the title of the proposal  in their comments  to facilitate review.  
Authority and Reference 
This regulatory action  is proposed under  the authority granted in California Health  and Safety  
Code,  sections 39500,  39600,  39601,  40000,  43013,  43018,  43100,  43101,  43102,  43104,  
43105,  43106,  43205.5,  and 43806;  and California Vehicle Code  section  28114. This action  is 
proposed to implement,  interpret,  and make specific  California Health  and Safety  Code  
sections 39500,  39600,  39601,  43013,  43018,  43100,  43101,  43102,  43104,  43105,  43106,  
43205.5,  43210.5,  and 43806;  and California Vehicle Code  section  28114.  
Informative Digest of Proposed Action and Policy Statement 
Overview (Gov. Code, § 11346.5, subd. (a)(3)) 
Sections  Affected:   
Proposed amendment  to California Code  of Regulations,  title 13, section s 1956.8, 1971.1,  
and 1975.1.  
Documents  Incorporated by Reference (Cal. Code Regs., tit.  1, § 20, 
subd.  (c)(3)): 
The following document  would be incorporated  in the regulation  by reference  as specified 
by section:  
● "California E xhaust  Emission Standards and Test Procedures for 2004 and Subsequent  
Model  Heavy- Duty  Diesel  Engines and Vehicles,"  adopted December  12, 2002,  as last 
amended on [Insert  Date  of Amendment ], incorporated  by reference  in 13 CCR 1956.8.  
● Title 40 C ode of Federal  Regulations, Part 86 “§ 86.010- 18 - On-board  Diagnostics for 
engines used in applications greater than 14,000 pounds GVWR, ” as last amended 
January 24, 2023,  incorporated  by reference in 13 CCR 1971.1.  
The above  listed document  is being amended by this regulation , and thus the amendment  
date would  be the date that the regulation is adopted by CARB.  3 Background and Effect of the Proposed  Regulatory  Action:  
Existing Regulatory  Requirements  
On-road HD vehicles1 operate  throughout  California and are an essential  part of the state’s  
economy;  they include  long- haul trucks,  drayage trucks,  transit buses,  refuse trucks,  and 
other  commercial  work  vehicles.  According  to California’s emissions inventory  model,  almost  
a million HD vehicles operate  on California roads  each  year.  These vehicles are significant  
sources of oxides of nitrogen (NOx), particulate  matter (PM), and greenhouse gas (GHG) 
emissions.  In fact, heavy -duty vehicles  comprise  the largest  NOx  emission source category in 
the state.  
New HD engines have been subject  to a nationwide NOx  standard of 0.20 grams  per brake  
horsepower  hour (g/bhp- hr) and a PM emission standard of 0.01 g/bhp- hr since  2010. In 
addition to these emissions standards,  California has also adopted programs  that 
substantially  reduce emissions from in- use heavy -duty vehicles. These programs  include 
vehicle  idling restrictions  and in- use fleet rules  such as the Truck  and Bus Regulation, which 
require the upgrade of older  trucks  and buses to newer  and cleaner  engines that meet 2010 
model  year (MY) engine standards by 2023.  To comply with these in- use regulations, fleets 
have  made  substantial  investments to purchase lower -emitting  vehicles.  
In 2013,  Califor nia established optional  low- NOx  standards2 for new HD engines,  with the 
most aggressive standard  being  0.02 g/bhp- hr, which  is 90 percent  below the 2010 HD 
standard.  The optional  low- NOx  standards were  developed to pave  the way for more  
stringent  mandatory standards by encouraging manufacturers  to develop and certify low-
NOx  engines,  and incentivizing potential  customers  to purchase  these low- NOx  engines.  
Since 2015,  a number  of engine families, some  using natural  gas and others  using liquefied 
petrol eum gas, have  been certified to the optional  NOx  standards.3  
On September  9, 2021,  California adopted the Omnibus regulation which primarily 
established  more  stringent  NOx  and PM standards applicable to new 2024 and subsequent  
MY medium - and HD diesel  and Otto -cycle  engines.4 For heavy -duty diesel  engines (HDDE), 
the regulation established more  stringent  standards on existing certification  cycles  such as 
the HD Transient  Federal  Test Procedure  (FTP),  the Supplemental  Emission Test Ramped 
Modal  Cycle (SET), and the CARB  Idle Test Procedure,  and new exhaust  emission standard s 
on a new certification  cycle  (low load cycle ). Furthermore,  to ensure that in- use emissions are 
controlled  during most of the vehicle’s operations,  the preexisting Not-To-Exceed HD in-use 
testing  methodology  was replaced with a more  represent ative 3-Bin Moving  Average  
 
1 Under  California regulations,  HD vehicles  are those  vehicles  with a gross vehicle  weight rating  (GVWR) greater 
than 8,500 pounds,  while medium- duty vehicles  are a subcategory  of heavy -duty vehicles  with a GVWR  between 
8,501 and 14,000 pounds.  Manufacturers  have  the option  to certify  medi um-duty engines  used  in vehicles  from  
10,001 to 14,000 pounds GVWR to the engine standards  specified for engines  in vehicles  over 14,000 pounds .  
2 Optional Reduced NOx  Standards  for Heavy -duty Vehicles  | CARB  
3 Optional Low NOx  Certified  Heavy-Duty  Engines- as of 02242022  (ca.gov)  
4 Heavy- Duty  Omnibus  Regulation | CARB  4 Window (3B-MAW)  methodology . The preexisting emissions warranty and useful  life periods 
were also lengthened  to reflect the longevity  of current HD vehicles.   
On January 24, 2023,  the United  States  Environmental  Protection  Agency  (U.S. EPA) finalized 
the federal  Clean  Trucks Plan (CTP)  NOx  rule, which sets stricter emission standards for new 
2027 and later MY HD engines and contains  elements similar to CARB’s  Omnibus regulation . 
In general,  CARB’s  2031 and later MY Omnibus standards and test procedures are more  
stringent  than the corresponding  provisions of the federal  CTP NOx  rule. Furthermore,  
U.S. EPA currently does n ot have  emission standards or emission -related  requirements  that 
are as stringent  as CARB’s  2024 through 2026 MY Omnibus requirements.   
Summary of Propos ed Amendments  
The Omnibus regulation currently contains  a provision  that allows manufacturers  to elect  to 
produce and sell a fraction  of their 2024 and 2025 MY HDDEs rated  below 525 bhp to the 
current  0.20 g/bhp- hr NOx  and 0.01 g/bhp- hr PM emission standards (hereinafter  referred  to 
as legacy  engines),  provided they offset  any resulting legacy  engine NOx  or PM emission 
deficits with credits  obtained from the HD zero-emission averaging set. If sufficient  credits 
from the zero-emission averaging set are not available, or such credits  are not available 
below a specified cost threshold,  then upon approval  by CARB’s EO, the manufacturer may 
offset  the deficits using combustion  engine  credits  from the same HDDE  averaging set. If 
credits  from the same HDDE  averaging set are not available, the manufacturer may carry 
over the NOx  or PM deficit balance generated by legacy engines until the end of the 2026 
MY, provided the manufacturer offsets the remaining legacy  engine generated deficit 
balance times  1.25 with credits  from the HD zero-emission averaging set or the same  HDDE  
averaging set. If at the end of the 2026 MY, a sufficient  quantity  of HD zero-emission or 
HDDE  credits  are not available for the manufacturer to o ffset the remaining legacy  engine 
generated deficit balance times  1.25,  the manufacturer,  upon approval  by CARB’s  EO, may 
offset  the legacy  engine emissio n deficits times  1.25 by performing  projects  in disadvantaged 
communities.  To utilize this option,  a manufacturer must certify at least  one engine family to 
the Omnibus requirements.  
As 2024 model  ye ar certification  approached,  CARB  staff became  aware  through 
manufacturer product  plans for 2024 to 2026 that while the technology for diesel -fueled 
Omnibus compliant  engines was available, manufacturers  did not intend to produce such 
engines for some  categories  of trucks  in California. Given  the impacts  to fleets manufacturers  
were projecting,  additional  flexibility was desired to enable a smoother  transition  to the 
omnibus standards.  CARB  staff is proposing  to amend the legacy  engine provisions in the 
Omnibus regulation to provide  additional  compliance  flexibility to allow manufacturers  to 
produce and certify greater  number s of 2024 through 2026 MY legacy  engines, while also 
ensuring the proposed amendments will not reduce the emissions benefits of the Omnibus 
regulation. CARB  staff is proposing two options for manufacturers  to choose from.   
Option  1 would keep the existing legacy  engine sales  limits of 45 percent  for MY 2024 and 
25 percent  for MY 2025 and extend the applicability to MY 2026 with a 10 percent  California 
legacy  engine limit. If a manufacturer exceeds the legacy  engine sales limits, deficits from the 
additional  one percent  sales volume  above  the limit would have  to be remediated at four 
times  the deficit balance.  Any legacy  engine sales above  the production  and sales limits 5 including the additional  one percent  volume  would be considered  as non-compli ant engine 
sales.   
Option  2 would be available to manufacturers that produce and sell medium  heavy -duty 
diesel  (MHDD)  engines and another  class  of HD engines. Under  this option,  MHDD  legacy 
engine sales would be limited to 60 percent  in each  of MYs 2024 and 2025.  The sales limits 
for combined  light  heavy- duty diesel  (LHDD)  and heavy  heavy -duty diesel  (HHDD)  engines 
would be 15 percent  in 2024 MY and 8 percent  in 2025  MY. If a manufacturer  exceeds the 
legacy  engine sales limits, deficits  from the additional  5 percent  sales volume  above  the limit 
for MHDDs , and additional  one percent sales volume  above  the limit for LHDDs and HHDDs  
would have  to be remediated at four times  the deficit  balance.  Any legacy  engine sales 
above  the distribution  limits including the additional  allowed exceedances would be 
considered  as non-compliant engine sales.  
The pathways  for offsetting legacy  engine emission deficits would remain  the same  as in the 
existing Omnibus regulation.  In addition,  the proposed amendments include other  
flexibilities including the ability to certify a legacy  engine family before certification  of the 
Omnibus compliant  engine family and the ability to start working on projects  in 
disadvantaged communities  as early as 2024 MY.  
The EO may also consider  other  changes to the sections  affected,  as listed on page 2 of this 
notice,  or other  sections within the scope of this notice,  during the course  of this rulemaking 
process.  
Objectives  and Benefits  of the Proposed Regulatory  Action:  
Objectives  
As 2024 model  year certification  approached,  CARB  staff became  aware  through 
manufacturer product  plans for 2024 to 2026 that while the technology for diesel -fueled 
Omnibus compliant  engines was available, manufacturers  did not intend to produce such 
engines for some  categories  of trucks  in California. Given  the impacts  to fleets,  additional  
flexibility was desired to enable a smoother  transition  to the Omnibus standards. CARB  staff 
is introducing the proposed amendments , which would provide  additional  flexibility to assure 
originally intended engine availability levels while maintaining the originally projected  
emissions reductions.  
Environmental  and Health  Benefits  
As discussed above,  similar to the existing  legacy  engine provisions,  manufacturers  would be 
required to offset  any excess NOx  and/or PM emissions deficits generated from legacy  
engine sales by using the same  pathways currently existing in the Omnibus regulation.  As a 
result,  the proposed amendments  are emissions- neutral ; that is, they are not projected  to 
provide  any additional  emission reductions,  nor are they expected  to result  in any emissions 
increases. E missions and health benefits expected from the Omnibus regulation as initially 
adopted would remain  the same.  6 Economic Impacts  
The proposed amendments are expected to be cost neutral  to manufacturers because the 
technology  cost savings gained from the sale of legacy  engines will be offset  by the cost for 
the credits  or projects  needed to offset  the legacy  engine deficits. There will be an 
operational  cost savings to the fleet operators  due to the decreased use of diesel  exhaust  
fluid (DEF)  in legacy  engines valued  at approximately $60 to $200 per engine on an annual  
basis. CARB  staff expects fleets to purchase new legacy  engines at an increased cost 
between $600 and $2,000 so they may utilize DEF savings.  The savings and costs  to the fleet 
owners are expected to have  a net zero change over the years  between 2024 through  2035.  
A detailed assessment  of the economic impacts  of the proposed regulatory  action  can be 
found in the Economic Impact Analysis chapter  of the Initial Statement of Reasons (ISOR) . 
Comparable Federal  Regulations:  
Both  California and U.S. EPA have  the authority and responsibility  to set emission standards 
for new HD engines and vehicles.  For the past several  decades,  California’s and U.S. EPA’s  
HD engine emissions standards and other  emission- related  requirements have largely  been 
harmonized.  Thus,  for many years  the regulated industry  has been able to design and 
produce a single product line of engines and vehicles that comply  with both  U.S. EPA and 
CARB  emission standards and sold in all 50 states.  So-called ‘‘50-state’’  certification  enable 
technology  suppliers and manufacturers  to efficiently produce a single set of reliable and 
compliant products.  
HD vehicles  comp rise the largest  NOx  emissions source  category in California, contributing  
to about  a third  of total statewide NOx  inventory.  As a result,  California urgently  needs to 
achieve  significant emission reductions  from  on-road HD vehicles in order  to meet  the 
California’s S tate Implementation  Plan (SIP) commitments  and protect public  health.  The 
Omnibus regulat ion is one of the biggest  measures in the 2016 State  SIP Strategy. The 
regulation,  as adopted on September  9, 2021, was developed to achieve  significant  NOx  
emission reductions  by requiring HD engines meet  stricter requirements beginning with MY 
2024.   
On January 24, 2023,  U.S. EPA finalized the CTP NOx  rule which sets stricter emission 
standards for new 2027 and later MY HD engines and has nearly  all the same  elements  as the 
Omnibus regulation. In general,  CARB’s  2031 and later MY Omnibus standards and test 
procedures  are more  stringent  than those of the CTP NOx  rule. Furthermore,  U.S. EPA 
currently does not have  emission standards or emission- related  requirements that are as 
stringent  as CARB’s  2024 through  2026 MY Omnibus requirements.  
An Evaluation of  Inconsistency  or Incompatibility  with  Existing  
State Regulations  (Gov.  Code,  § 11346.5, subd. (a)(3)(D)): 
During the process of developing  the proposed amendments to the Omnibus regulation, 
CARB  conducted  a search  of any similar regulations on this topic  and concluded these  
regulations  are neither  inconsistent  nor incompatible  with existing  state  regulations.  7 Disclosure Regarding the Proposed Regulation 
Fiscal  Impact/Local  Mandate Determination Regarding the 
Proposed Action  (Gov.  Code,  § 11346.5, subds.  (a)(5)&(6)): 
The determinations of the Board's  EO concerning  the costs  or savings incurred  by public  
agencies and private  persons and businesses in reasonable compliance  with the proposed 
regulatory  action  are presented below.  
Under  Government Code  sections 11346.5,  subdivision (a)(5) and 11346.5,  subdivision (a)(6), 
the EO has determined that the proposed regulatory  action  would not create  a net costs  or 
savings to any State  agency,  would not create  costs  or savings in federal  funding to the State,  
would not create  a net increase in costs  or mandate  to any local agency  or school  district,  
whether  or not reimbursable by the State  under  Government  Code,  title 2, division 4, part 7 
(commencing  with section 17500),  or other  nondiscretionary  cost or savings to State  or local 
agencies.  
The proposed regulatory  action  would not create  a net cost to state  agencies,  local agencies 
or school  districts  purchasing and operating  HD vehicles for their fleets.  These agencies and 
school  districts  with fleets are expected to have  an upfront  cost that is balanced with annual  
operational  savings over the ten years  of useful  life as discussed in the Economic Impacts  
section  on page six, above . Additionally, sales taxes  are levied in California to fund a variety 
of programs  at the state  and local level.  The expected increase in purchase price  of a HD 
vehicle  and the subsequent  savings in operational  costs  for a legacy  engine are expected  
balance one another  and they will have  no net impact over the regulatory useful  life of the 
engines. 
Housing  Costs  (Gov.  Code,  § 11346.5, subd.  (a)(12)): 
The EO has also made  the initial determination  that the proposed amendments to the 
Omnibus regulation will not have  a signif icant effect  on housing costs.  
Significant  Statewide Adverse Economic  Impact  Directly Affecting  
Business,  Including Ability  to Compete  (Gov.  Code,  §§ 11346.3, 
subd.  (a), 11346.5, subd.  (a)(7), 11346.5, subd.  (a)(8)): 
The EO has made  an initial determinatio n that the proposed regulatory action  would not 
have  a significant statewide adverse economic impact  directly affecting businesses,  including 
the ability of California businesses to compete  with businesses in other  states,  or on 
representative  private  persons.  8 Results of The Economic Impact Analysis/Assessment (Gov. Code, 
§ 11346.5, subd. (a)(10)):  
Non-Major  Regulation:  Statement  of the Results  of the Economic  
Impact  Assessment  (EIA):  
(A) The creation  or elimination of jobs within the State  of California. 
The proposed regulat ory action  is expected  to have  no impact to the creation  or elimination 
of jobs within the State  of California.  
(B) The creation  of new business or the elimination of existing businesses within the 
State  of California. 
The proposed regulat ory action  is expected  to have  no impact to the creation  of new 
businesses or the elimination of existing businesses within the State  of California.  
(C) The expansion of businesses currently doing  business within the State  of California.  
The proposed regulatory action  is not expected to impact the expansion of businesses 
currently doing business within the State  of California.  
(D) The benefits of the regulation  to the health and welfare of California residents,  
worker  safety,  and the state’s  environment.  
The proposed regulatory  action  is not expected to have an impact to the health  and welfare 
of California residents,  worker  safety,  and the state’s  environment.  
Effect on Jobs/Businesses:  
The EO has determined that the proposed amendments  would not affect the creation  or 
elimination of jobs within the State  of California, the creation  of new businesses or 
elimination of existing businesses  within the State  of California, or the expansion of 
businesses currently doing business within the State  of California. A d etailed assessment  of 
the economic impacts  of the proposed regulatory action  can be found in the Economic 
Impact Analysis in the ISOR.   
Benefits of the Proposed Regulation:  
The objective  of the proposed amendments is to address some  unanticipated changes to 
manufacturers'  product  lines and ensure adequate product availability during the 2024- 2026 
MY transition  years  as manufacturers  adjust  to the new lower  Omnibus NOx  emission 
standards.   
A summary  of these benefits is provided,  please refer  to “Objectives  and Benefits”,  under  
the Informative  Digest  of Proposed Action  and Policy Statement  Overview  Pursuant  to 
Government Code  section  11346.5,  subdivision (a)(3) discussion on page five.  9 Business  Report  (Gov.  Code,  §§ 11346.5, subd. (a)(11); 11346.3, 
subd.  (d)):  
In accordance  with Government  Code  sections 11346.5,  subdivisions (a)(11)  and 11346.3,  
subdivision  (d), the EO finds the reporting  requirements of the proposed amendments  which 
apply  to businesses are necessary  for the health,  safety,  and welfare of the people of the 
State  of California. 
Cost Impacts  on Representative Private  Persons  or Businesses  
(Gov.  Code,  § 11346.5, subd.  (a)(9)): 
In developing this regulatory proposal,  CARB  staff evaluated the potential  economic impacts  
on representative  private  persons or businesses.  CARB  is not aware  of any cost impacts  that 
a representative private  person would necessarily  incur in reasonable compliance  with the 
proposed action.  A business purch asing and operating  fleets may incur  an initial cost 
between $600 to $2,000 per engine and an annual  operational  cost savings between $60 to 
$200 per engine depending on engine class.  Over the 10 years  of regulatory  useful  life of 
these legacy  engines,  the costs  and saving balance each  other  out and there is zero net fiscal 
impact to businesses. A detailed assessment  of the economic impacts  of the proposed 
regulatory  action  can be found in the Economic Impact Analysis chapter of the ISOR. 
Effect on  Small  Business  (Cal. Code  Regs.,  tit. 1, § 4, subds. (a)  and 
(b)): 
The EO has also determined under  California Code  of Regulations,  title 1, section  4, that the 
proposed regulatory  action  would affect small  businesses. Small  businesses are defined here 
to be California fleets  that own three  or fewer  HD vehicles.  A small  business purchasing and 
operating fleets may incur  an initial cost between $600  to $2,000 per engine  and an annual  
operational  cost savings between $60 to $200 per engine depending on engine class.  Over 
the 10 years  of regulatory useful  life of these legacy  engines,  the costs  and saving balance 
each  other  out and there  is zero net fiscal impact to businesses.  A detailed assessment  of the 
economic impacts  of the proposed regulatory  action  can be found in the Economic Impact 
Analysis chapter VIII of the ISOR. 
Consideration  of Alternatives (Gov.  Code,  § 11346.5, subd.  
(a)(13)): 
Before taking final action  on the proposed regulatory  action,  the EO must  determine that no 
reasonable  alternative  considered by the EO or that has otherwise been identified and 
brought  to the attention  of the EO would be more  effective in carrying  out the purpose  for 
which the action  is proposed,  would be as effective and less burdensome to affected  private  
persons than the proposed action,  or would be more  cost- effective  to affected private  
persons and equally  effective in implementing the statutory policy or other  provisions of law.  10 State Implementation Plan Revision  
If adopted by CARB,  CARB  plans to submit  the proposed amendments to the Omnibus 
regulation to the U.S. EPA for approval  as a revision  to the California SIP required by the 
federal  Clean  Air Act (CAA).  The adopted regulatory action  would be submitted as a SIP 
revision  because it amends regulations intended to reduce  emissions of air pollutants in 
order  to attain  and maintain  the National  Ambient  Air Quality Standards promulgated by 
U.S. EPA pursuant  to the CAA.  
Environmental Analysis  
CARB  has determined that the proposed amendments  are exempt  from the requirements of 
the California Environmental  Quality Act (CEQA).  CARB’s  regulatory  program,  which involves  
the adoption,  approval,  amendment,  or repeal  of standards,  rules,  regulations,  or plans for 
the protecti on and enhancement  of the State’s  ambient  air quality,  has been certified  by the 
California Secretary for Natural  Resources under  Public  Resources Code  section  21080.5 of 
CEQA (14 CCR 15251(d)).  Public  agencies with certified regulatory  programs  are exempt  
from certain  CEQA  requirements,  including but not limited to, preparing environmental  
impact reports,  negative declarations,  and initial studies.  CARB,  as a lead agency,  prepares a 
substitute environmental  document  (referred  to as an “Environmental  Analys is” or “EA”)  as 
part of the Staff Report  prepared for a proposed action  to comply with CEQA  (17 CCR 
60000- 60008).  If the proposed amendments  are finalized, a Notice  of Exemption  will be filed 
with the Office of the Secretary for the Natural  Resources Agenc y for public  inspection.  
CARB  has det ermined that the proposed amendments  to the Omnibus regulation  is exempt  
from CEQA  under  the “general  rule”  or “common  sense”  exemption (14 CCR 15061(b)(3)).  
The common  sense exemption states  a project is exempt  from CEQA if “the activity is 
covered  by the general  rule that CEQA applies only to projects  which have  the potential  for 
causing a significant  effect on the environment.  Where  it can be seen with certainty that 
there  is no possibility  that the activity in questi on may have  a significant  effect  on the 
environment,  the activity is not subject  to CEQA.  
Based on CARB’s  review,  the proposed amendments would not result  in increased criteria  or 
toxics  pollutant  emissions,  nor GHG  emissions,  compared  to existing conditio ns. The 
proposed amendments  would not result  in any new or modified facilities, nor any other  types  
of construction  or operational -related  impacts  that could  lead to potential  adverse 
environmental  impacts.  It can therefore  be seen with certainty that there is no possibility  that 
the proposed amendments may result  in a significant  adverse impact on the environment;  
therefore,  this activity is exempt  from CEQA.  
Special Accommodation Request  
Consistent  with California Government  Code  section  7296.2,  special  accommodation  or 
language needs may be provided  for any of the following: 
• An interpreter  to be available at the hearing;  11 • Documents  made  available in an alternate  format or another  language;  and 
• A disability- related  reasonable accommodation.  
To request  these special  accommodations  or language needs,  please contact  the Clerks’  
Office at cotb@arb.ca.gov  or (916)  322-5594 as soon  as possible,  but no later than ten 
business days before the scheduled EO hearing, if one is requested. TTY/TDD/Speech to 
Speech users may dial 711 for the California Relay  Service.  
Consecuente c on la secci ón 7296.2 del Código de Gobierno  de California, una acomodaci ón 
especial  o necesidades ling üísticas  pueden ser suministradas para cualquiera  de los 
siguientes:  
• Un intérprete  que esté disponible  en la audiencia;  
• Documentos disponibles en un formato  alterno  u otro idioma; y 
• Una acomodaci ón razonable  relacionados  con una incapacidad.  
Para solicitar estas comodidades  especiales  o necesidades de otro idioma, por favor  llame a 
la oficina del Consejo  al cotb@arb.ca.gov o (916)  322-5594 lo más pronto  posible,  pero  no 
menos de 10 días  de trabajo  antes del día programado  para la audiencia  del Consejo , si lo 
solicitan. TTY/TDD/Personas  que necesiten este servicio  pueden marcar el 711 para el 
Servicio  de Retransmisi ón de Mensajes de California. 
Agency Contact Persons  
Inquiries concerning the substance of the proposed regulatory  action  may be directed  to the 
agency  representative  Daniel  Hawelti,  Staff Air Pollution Specialist , On-Road  Heavy- Duty  
Diesel  Section,  at (951)  542-3195 or (designated back -up contact)  Mitzi  Magtoto,  Staff Air 
Pollution Specialist , On-Road  Heavy- Duty  Diesel  Section , at (916)  323-8975.   
Availability of Documents 
CARB  staff has prepared a Staff Report:  ISOR  for the proposed regulatory  action,  which 
includes a summary of the economic and environmental  impacts  of the proposal.  The report 
is entitled:  Staff Report:  Initial Statement of Reasons-P ublic  Hearing  to Consider  the 
Proposed Amendments to the Heavy-D uty Engine and Vehicle Omnibus Regulation. 
Copies of the ISOR and the full text of the proposed regulatory  language, in underline  and 
strikeout format to allow for comparison  with the existing regulations,  may be accessed  on 
CARB’s  website listed below,  on August  1, 2023. Please contact Chris  Hopkins,  Regulations 
Coordinator,  at Chris.Hopkins@arb.ca.gov  or (279)  208 7347 if you need physical  copies of 
the documents.  Pursuant  to Government Code  section  11346.5,  subdivision  (b), upon request  
to the aforementioned  Regulations Coordinator,  physical  copies would be obtained from the 
Public  Information  Office, California Air Resources Board,  1001 I Street,  Visitors  and 
Environmental  Services Center,  First Floor,  Sacramento,  California,  95814.  
Further,  the a gency  representative to whom  nonsubstantive inquiries concerning the 
proposed administrative  action  may be directed is Chris  Hopkins,  Regulations Coordinator,  
(279)  208 7347. The Board  staff has compiled  a record  for this rulemaking action,  which 12 
includes all the information upon which the proposal  is based.  This material  is available for 
inspection upon request  to the contact persons.  
Hearing Procedures  
The public  hearing will be conducted by the EO in accordance  with the California 
Administrative  Procedure  Act, Government  Code,  title 2, division 3, part 1, chapter  3.5 
(comme ncing with section 11340) , if a public  hearing is requested.  For details on how to 
request  a hearing,  please refer  to the “Written  Comment  Period  and Submittal  of 
Comments”  section  of this document . 
Following the close  of the comment period, the EO may adopt  the regulatory  language  as 
originally proposed,  or with non-substantial  or grammatical  modifications.  The EO may also 
approve  for adoption  the proposed regulatory  language with other modifications if the text 
as modified is sufficiently related  to the originally proposed text that the public  was 
adequately  placed on notice  and that the regulatory language as modified could result  from 
the proposed regulatory  action.  If this occurs,  the full regulatory text, with the modifications 
clearly indicated,  will be made  available to the public,  for written  comment,  at least  15-days 
before final adoption.  
The public  may request  a copy of the modified regulatory  text, if applicable,  from CARB’s  
Public  Information  Office, California Air Resources Board,  1001 I Street,  Visitors  and 
Environmental  Services Center,  First Floor,  Sacramento,  California,  95814.  
Final Statement of Reasons Availability  
Upon  its completion,  the Final  Statement of Reasons (FSOR)  will be available and copies  may 
be requested from the agency  contact persons in this notice,  or may be accessed on CARB’s  
website listed below.  
Internet Access  
This notice,  the ISOR and all subsequent  regulatory documents,  including the FSOR,  when 
completed,  are available on CARB’s  website for this rulemaking at 
https://ww2.arb.ca.gov/rulemaking/2023/hdomnibus2023  
California Air Resources Board  
_________________________________ 
Steven  S. Cliff, Ph.D.  
Executive  Officer 
Date:  July 18, 2022 
The energy  challenge facing California is real. Every Californian  needs to take immediate  
action  to reduce energy  consumption.  For a list of simple ways  you can reduce demand and 
cut your energy  costs,  see CARB’s  website (www.arb.ca.gov).