State Implementation Plans

SIP-Related Documents 

The U.S. Environmental Protection Agency (EPA) develops National Ambient Air Quality Standards (NAAQS) to protect human health and the environment. DAQ is required to develop long-term planning documents such as State Implementation Plans (SIPs) to demonstrate how the NAAQS will be achieved, maintained, and enforced. After an area reaches attainment, a Redesignation Request and Maintenance Plan is developed to demonstrate maintenance for at least the next 10-year period. These SIPs and Maintenance Plans become the Clark County portion of the Nevada SIP. DAQ also develops Transportation Conformity Plans, in collaboration with the Regional Transportation Commission of Southern Nevada (RTC), the MPO for Clark County, to address transportation conformity issues in Southern Nevada.

Currently, the Las Vegas Valley (Hydrographic Area 212) is classified as marginal nonattainment for the 2015 Ozone (O3)NAAQS. Hydrographic Area 212 is an attainment area subject to a maintenance plan for the CO and PM10 NAAQS. Hydrographic Areas 164A, 164B, 165, 166, 167, 212, 213, 214, 216, 217, and 218 (excluding the Moapa River Indian Reservation and the Fort Mohave Indian Reservation) are attainment areas subject to a maintenance plan for the 1997 O3 NAAQS. Click here for a map detailing Clark County's area designations.

Particulate Matter (PM10)

The Las Vegas Valley (HA 212) within Clark County is a maintenance area for PM10. DAQ submitted a Redesignation Request and Maintenance Plan in August 2012. On October 6, 2014, EPA approved our request and designated Clark County as an attainment area, effective November 5, 2014.

DAQ submitted a SIP in 2001, which explains how the area will attain the NAAQS for PM10.  The plan is the cumulative program of all pollution control strategies, control measures, emission inventories, attainment demonstration, and state statute and local rules implemented. Final EPA approval of the plan was effective July, 2004.

Subsequently, DAQ submitted a Milestone Achievement Report (MAR) in June 2007. The MAR documents Clark County’s attainment of the 24-hour PM10 NAAQS. On August 3, 2010, EPA made the determination that the Las Vegas Valley was in attainment with the PM10 NAAQS (75 FR 45485), and the area was redesignated to attainment with the approval of the maintenance plan and designation request in October 2014.

SIP Documents Document Elements
PM10 Redesignation Request and Maintenance Plan (2012) PM10 Redesignation Request and Maintenance Plan - without Appendices
App A - Technical Support Document
App B - Documentation of the Public Review Process
EPA Actions 79 FR 60078: EPA Notice of Final Approval (October 2014)           
79 FR 42258: EPA Notice of Proposed Approval (July 2014)
Milestone Achievement Report (2007) Milestone Achievement Report - without Appendices
App A - Monitoring Data
App B - High Wind Events
App C - Saturation Monitoring Study
App D - Land and Road Soil Stabilization Study
App E - Refined Emission Factors
App F - Construction Inventory
App G - RTP Chapter 5
App H - Proportional Rollback Model
PM10 State Implementation Plan for Clark County (2001) PM10 SIP Plan - without Appendices
App A - Design Value Determination
App B - Emission Inventory Methodology
App C - Estimation of Valley-Wide PM10 Emissions
App D - PM10 Emissions Inventory of Sources Surrounding Monitoring Sites
App E - Inventory Projections Methodology and Calculations
App F - Control Measure Development Process
App G - Air Quality Regulations and Section 94 Handbook
App H - Clark County Health District Resolutions
App I - Letter from Nevada Department of Motor Vehicles and Public Safety
App J - Street Sweeping Equipment and Paved Road Cleanup Programs
App K - Rollback Methodology
App L - Controlled Emission Inventory Development
App M - Reasonable Further Progress Inventory of 2003
App N - Mobile Source Emissions Budget
App O - Public Review Process
App P - Comments Received
App Q - Public Hearing Documentation
App R - Residential Wood Combustion Control Measures  
EPA Actions 69 FR 32273: EPA Notice of Final Approval (June 2004)
68 FR 2954: EPA Notice of Proposed Approval (January 2003)
EPA Fact Sheet for Proposed Approval of PM10 SIP 
EPA Technical Support Document for Proposed Approval 
 
Carbon Monoxide (CO)

The Las Vegas Valley (HA 212) within Clark County is a maintenance area for CO.  DAQ submitted a Redesignation Request and Maintenance Plan in 2008. On September 27, 2010, EPA approved our request and designated Clark County as an attainment area, effective September 27, 2010 (75 FR 59090).

DAQ submitted a SIP in 2000, describing the control measures and technologies to bring the Las Vegas Valley into compliance with the CO NAAQS. This plan was approved by EPA, effective October 21, 2004 (69 FR 56351). On June 1, 2005, EPA issued a determination of attainment for the Las Vegas Valley CO nonattainment area (70 FR 31353). A revision of the SIP was submitted in 2005 to update the CO emissions budgets using the latest model approved by EPA for transportation conformity determinations (MOBILE6). This revision was approved by EPA on August 7, 2006 (71 FR 44587).   
 
SIP Documents Document Elements
Second 10-Year CO Limited Maintenance Plan: Las Vegas Valley Maintenance Area (2019)
Entire Document
Second 10-Year CO Limited Maintenance Plan: Las Vegas Valley Maintenance Area
App A - Letter from EPA, dated August 7, 2017
App B - Documentation of Public Review Process

NDEP Review of CO Limited Maintenance Plan and Recommendations to EPA
EPA Actions 86 FR 58579: EPA Notice of Final Approval (October 2021)
86 FR 41416: EPA Notice of Proposed Approval (August 2021)
CO Maintenance Plan and Redesignation Request (2008) CO Redesignation Request and Maintenance Plan - without Appendices
App A - Wintertime Gasoline Spec Study
App B - Technical Support Document
App C - Public Review Process

NDEP Review of CO Maintenance Plan and Recommendations to EPA
EPA Actions 75 FR 59090: EPA Notice of Final Approval (September 2010)
75 FR 44734: EPA Notice of Proposed Approval (July 2010)
EPA Fact Sheet for Proposed Final Approval of CO Redesignation Request and Maintenance Plan
CO State Implementation Plan Revision (2005) CO State Implementation Plan Revision - without Appendices
App A - Technical Support Document
App B - Carbon Saturation Study
App C - Effectiveness of I&M
App D - Airport Modeling Studies
App E - RTC Support letter
App F - Public Review Process
EPA Actions 71 FR 44587: EPA Notice of Final Approval (August 2006)
71 FR 26910: EPA Notice of Proposed Approval (May 2006)
EPA Fact Sheet for Proposed Approval of CO SIP Revision
CO State Implementation Plan for the Las Vegas Valley (2000) CO State Implementation Plan for the Las Vegas Valley - without Appendices
App A - Emission Inventory
App B - Transportation Documentation
App C - Modeling Documentation
App D - Regulations and Policies
App E - Supplemental Technical Support Documentation
EPA Actions

69 FR 56351 EPA Notice of Final Approval (September 2004)
68 FR 4141: EPA Notice of Proposed Approval (January 2003)
EPA Fact Sheet for Proposed Approval of CO SIP
EPA Technical Support Document

 
Ozone (O3)

2015 O3 NAAQS

In September 2016, Clark County submitted its Area Designation Recommendations for the 2015 O3 NAAQS recommending portions of the County be designated nonattainment. On December 20, 2017, EPA issued its 120-day 2015 O3 designations letter identifying portions of the County that would be designated nonattainment. Based on the availability of more recent monitoring data, on February 23, 2018, Clark County/NDEP revised its recommendation and submitted a response to EPA's proposed designations requesting that only the Las Vegas Valley (HA 212) be designated nonattainment.  

On June 4, 2018, EPA designated the Las Vegas Valley (HA 212) as a nonattainment area for the 2015 O3 NAAQS, effective August 3, 2018 (83 FR 25776).   

2008 O3 NAAQS
 
On May 21, 2012, EPA designated Clark County as attainment/unclassifiable for the 2008 O3 NAAQS, effective July 20, 2012 (77 FR 30088).

On June 12, 2013, DAQ enrolled in EPA's O3 Advance program, a collaborative effort between EPA and air agencies aimed at preserving air quality in ozone attainment areas. Participating agencies work with EPA to identify, evaluate, and implement measures and programs to reduce ozone and continue making improvements in air quality. Progress reports detailing program activities, achievements, and identifying future program goals are submitted on an annual basis.

1997 O3 NAAQS
 
An O3 Early Progress Plan that provides the basis for establishing early transportation conformity budgets for the Clark County 8-hour O3 nonattainment area was submitted to EPA in 2008, and approved in 2009. A Redesignation Request and Maintenance Plan for the 1997 8-hour O3 NAAQS was submitted in April 2011. On January 8, 2013, EPA approved our request and the Clark County nonattainment area was redesignated to attainment for the 1997 8-hour O3 NAAQS, effective February 7, 2013.   

SIP documents Document elements
Revision to the Nevada SIP for the 2015 O3 NAAQS: Nonattainment Major NSR Requirements (2021) Entire Document Revision to the Nevada SIP for the 2015 O3 NAAQS: Nonattainment Major NSR Requirements- without Appendices
App A- Documentation of Public Review Process

NDEP Review of NNSR SIP Revision and Recommendations to EPA
EPA Actions Pending
Revision to the Nevada SIP for the 2015 O3 NAAQS: Emissions Inventory and Emissions Statement Requirements (2020) Entire Document Revision to the Nevada SIP for the 2015 O3 NAAQS: Emissions Inventory and Emissions Statement Requirements- without Appendices
App A- Technical Support Document
App B- Documentation of Public Review Process

NDEP Review of Emissions Inventory and Emissions Statement SIP Revision and Recommendations to EPA 
EPA Actions Pending
Revision to Motor Vehicle Emissions Budgets for the 1997 O3 NAAQS (2020) Entire Document  Revision to Motor Vehicle Emissions Budgets for the 1997 O3 NAAQS - without Appendices
App A- Technical Support Document
App B - Documentation of Public Review Process

NDEP Review of MVEB SIP Revision and Recommendations to EPA
EPA Actions 86 FR 59643: EPA Notice of Final Approval (October 2021)
86 FR 43461: EPA Notice of Proposed Approval (August 2021)
Revision to Motor Vehicle Emissions Budgets in O3 Redesignation Request and Maintenance Plan (2018) Entire Document  Revision to Motor Vehicle Emissions Budgets in O3 Redesignation Request and Maintenance Plan - without Appendices
App A - Technical Support Document
App B - Documentation of Public Review Process

NDEP Review of MVEB SIP Revision and Recommendations to EPA
EPA Actions 84 FR 44699: EPA Notice of Final Conditional Approval (August 2019)
84 FR 33035: EPA Notice of Proposed Conditional Approval (July 2019)
O3 Redesignation Request and Maintenance Plan (2011) Entire Document O3 Redesignation Request and Maintenance Plan - without Appendices
App A - Technical Support Document
App B - EPA AQS Design Value Report 2006-2009
App C - Documentation of the Public Review Process
EPA Actions 78 FR 1149: EPA Notice of Final Approval (January 2013) 
77 FR 67600: EPA Notice of Proposed Approval (November 2012)
O3 Early Progress Plan (2008) Entire document O3 Early Progress Plan - without Appendices
App A - Consolidated Emissions Inventory
App B - Air Quality regulations
App C - 2005 CCROPS Study
App D - Public review Process
EPA Actions 76 FR 17343: EPA Determinaton of Attainment for the Clark County 8-hour O3 Nonattainment Area (March 2011)

74 FR 22738: EPA Adequacy Status of Motor Vehicle Emissions Budgets in Submitted Early Progress Plan (May 2009)
SIP-Related Documents Document Elements
O3 Advance Program Progress Report O3 Advance Program Progress Report (2019)
 
Infrastructure SIP

The Federal Clean Air Act requires States to prepare Infrastructure SIPs (I-SIP) any time EPA promulgates a new or revises an existing NAAQS and is required whether or not an area is in compliance with a new standard. In accordance with this requirement, Clark County prepares its portion of the I-SIP to demonstrate it has the programs in place to implement, maintain, and enforce the NAAQS. These I-SIPs become part of the Nevada I-SIP. The I-SIP addresses the following air quality program elements: permitting; air quality modeling; enforcement; ambient air monitoring; and, confirmation of adequate personnel, resources, and legal authorities.  

The Sulfur Dioxide (SO2) NAAQS was revised in 2010 and the I-SIP was submitted to NDEP in May 2013 for inclusion as a revision to the Nevada SIP.

The Ozone (O3) NAAQS was revised in 2008 and the I-SIP was submitted to NDEP in February 2013 for inclusion as a revision to the NV SIP. The O3 NAAQS was revised in 2015 and the I-SIP was submitted to NDEP in September 2018 for inclusion as a revision to the Nevada SIP.

The Nitrogen Dioxide (NO2) NAAQS was revised in 2010 and the I-SIP was submitted to NDEP in December 2012 for inclusion as a revision to the Nevada SIP. 

The Lead (Pb) NAAQS was revised in 2008 and the I-SIP was submitted to NDEP in July 2012 for inclusion as a revision to the Nevada SIP. 

In 2008, the Nevada Department of Environmental Protection (NDEP) submitted a consolidated I-SIP for the 1997 8-hour O3 NAAQS, and the 1997 and 2006 NAAQS for PM2.5. This was a joint effort between NDEP, Washoe County Health District, and DAQ.  EPA published a proposed rule for approval of the I-SIP on August 3, 2012. The final rule was promulgated on October 23, 2012.
 
SIP Documents Document Elements
SO2 Infrastructure SIP (2013) SO2 I-SIP
EPA Actions   80 FR 67652: EPA Notice of Final Approval (November 2015)
2015 O3 Infrastructure SIP (2018) 2015 O3 I-SIP
EPA Actions pending
2008 O3 Infrastructure SIP (2013)  2008 O3 I-SIP
EPA Actions      80 FR 67652: EPA Notice of Final Approval (November 2015)
NO2 Infrastructure SIP (2012)          NO2 I-SIP
EPA Actions  80 FR 67652: EPA Notice of Final Approval (November 2015)
Pb Infrastructure SIP (2012) Pb I-SIP
EPA Actions     79 FR 15697: EPA Notice of Final Approval (March 2014)
78 FR 64430: EPA Notice of Proposed Approval (October 2013)
1997 O3, and 1997 and 2006 PM2.5 I-SIP   To access these I-SIP submittals, please visit:
https://ndep.nv.gov/air/planning-and-modeling/regulations-and-sip-development 
EPA Actions          77 FR 64737: EPA Notice of Final Approval (October 2012)
77 FR 46361: EPA Notice of Proposed Approval (August 2012)
 
Transportation Conformity Plan

The Transportation Conformity Plan details consultation criteria, policies, and procedures that applicable local, state and federal agencies must follow when addressing transportation conformity issues within Clark County. DAQ updated the plan in 2008. In July 2008, EPA issued a finding that the Transportation Conformity Plan fulfilled the requirements in 40 CFR Part 51, Appendix V. Subsequently, EPA issued a direct final rule in November 2008.

SIP Documents Document Elements
Transportation Conformity Plan (2008) Transportation Conformity Plan
EPA Actions 73 FR 66182: EPA Notice of Direct Final Rule (November 2008)
Technical Support Document for Proposed Rule
EPA Completeness Finding Letter (July 2008)  
 
For more information or questions about SIP documents, contact Araceli Pruett at (702) 455-3206.