State of Wisconsin 

DEPARTMENT OF NATURAL RESOURCES 

101 S. Webster Street 

Box 7921 

Madison WI 53707-7921 

December 23, 2015 

Dr. Susan Hedman 

U.S. Environmental Protection Agency (EPA) - Region 5 

77 West Jackson Boulevard 

Mail Code:R-19J 

Chicago, IL 60604-3507 

Scott Walker, Governor 

Cathy Stepp, Secretary 

Telephone 608-266-2621 

Toll Free 1-888-936-7463 

TTY Access via relay- 711 

Subject: Proposed Revision to the State Implementation Plan (SIP) for the Milwaukee-RacineWaukesha County Fine Particulate (PM2.5) National Ambient Air Quality (NAAQS) Area 

Dear Regional Administrator Hedman: 

The Wisconsin Department of Natural Resources (WDNR) is requesting approval of the enclosed revision to the 

motor vehicle emissions budgets (MVEBs) for the approved Milwaukee-Racine- Waukesha area maintenance plan 

for the 2006 24 -Hour PM25 NAAQS. The WDNR is proposing to allocate a portion of the safety margin for 

volatile organic compounds (VOCs) to the area's 2020 and 2025 MVEBs for transportation conformity purposes. 

This allocation will still maintain the total emissions for the area at or below the attainment level required by the 

transportation conformity regulations while providing for transportation growth. The transportation conformity 

budget for oxides of nitrogen (NOx), sulfur dioxide (S02), and direct PM 25 will remain the same as the previously 

approved MVEBs in the maintenance plan. 

In accordance with ss. 285.11 ( 5) and ( 6) and ch. NR 4 01, Wis. Adm. Code, the WDNR collaborated with the 

Wisconsin Department of Transportation (WisDOT), the Southeast Regional Planning Commission (SEWRPC), 

the EPA, and the Federal Highway Administration (FHW A) to develop these revised 2020 and 2025 MVEBs. 

These MVEBs will be used to determine conformity when SEWRPC updates its next long term transportation and 

land use plan in the spring of 2016. 

Should you have any questions or comments on this proposed SIP revision, please contact Mike Friedlander at 

(608) 267-0806 or Michael.friedlander@wisconsin.gov. Thank you for your attention to this important air quality 

matter. 

Sincerely, 

Gail Good, Director 

Air Management Program 

dnr.wi.gov 

wisconsin.gov Naturally WISCONSIN 
cc: Pat Stevens-AD/8 

Aileen Switzer- WisDOT 

Rebecca Burkel - WisDOT 

Pat Trainer- WisDOT 

Michael Leslie- USEPA 

Christopher Bertch- FTA 

Dwight McComb- FHW A 

Christopher Hiebert- SEWRPC 

Attachments -

Page 2 

Attachment 1 -WDNR Proposed Revision to the SIP for the 2006 24-Hour PM25 N AAQS Maintenance 

Attachment 2- Public hearing notice for Proposed Revision to the SIP for the 2006 24-Hour PM2.5 

NAAQS Maintenance Area 

Attachment 3 - SIP Revision Certification 
The State of Wisconsin’s

Revision to the Motor Vehicle Emissions Budgets 

Included in the Milwaukee-Racine-Waukesha County 

Fine-Particulate National Ambient Air Quality (NAAQS) 

Maintenance Areas

Prepared by the Wisconsin Department of Natural Resources

September 2015
i

Table of Contents

1. Introduction................................................................................................................................ 1

2. Background and Purpose ........................................................................................................... 1

2.1 Fine Particulate Matter (PM 2.5) and Its Formation ............................................... 1

2.2 National Ambient Air Quality Standard for Fine Particulate Matter...................... 1

2.3 Wisconsin’s 2006 PM 2.5 NAAQS Maintenance Area ........................................... 2

2.4 Transportation Conformity ..................................................................................... 4

2.5 Revised Motor Vehicle Emission Budgets for VOCs............................................. 5

3. Public Participation.................................................................................................................... 6

Figures and Tables

Figure 1 Wisconsin Maintenance Area under the 2006 PM 2.5 NAAQS

Table 1 VOC Emissions Safety Margin under the 2006 PM 2.5 Maintenance Plan

Table 2 Proposed Revised Motor Vehicle Emissions Budgets for VOCs 
1

1. Introduction 

This plan establishes revised motor vehicle emission budgets (MVEBs) for the 2006 PM2.5 

Milwaukee-Racine-Waukesha Maintenance Area. The budgets are for VOC emissions for the 

years 2020 and 2025 and would be used in Wisconsin’s regional transportation conformity 

determinations if they are approved by EPA. The proposed revisions are consistent with 

continued maintenance of the 2006 PM2.5 NAAQS and should be approved accordingly.

2. Background and Purpose

2.1 Fine Particulate Matter (PM 2.5) and Its Formation 

Particle pollution, also called particulate matter or PM, consists of solid particles or liquid 

droplets suspended in the air. Fine particles (PM2.5) may be emitted directly into the atmosphere 

but are more commonly created by reactions of other pollutants, such as nitrogen oxides (NOx), 

sulfur dioxide (SO2), organic carbon, and ammonia. Sources of these precursor pollutants 

include power plants, industries, and automobiles. Wind can carry these particles hundreds of 

miles from their sources. PM2.5 levels typically peak in winter but concentrations can also be 

high in summer.

Exposure to these fine particles and droplets can cause serious health problems in humans, 

especially those with respiratory conditions such as asthma and cardiac disease. PM2.5 pollution 

scatters light and is the major cause of reduced visibility in the United States. Many fine 

particles can also cause acid rain and make lakes and streams more acidic. Deposition of 

nitrogen-containing particles may change the nutrient balance in lakes and rivers, affecting the 

diversity of ecosystems or damaging forests or crops. In addition, particle pollution can damage 

statues, monuments, and buildings made of stone and other materials.

To reduce particle pollution, state and federal regulations target NOx and SO2 emissions from 

power plants and industrial combustion sources. Additionally, mobile source control programs 

help reduce organic carbon and NOx emissions through low-emission vehicles and cleaner 

gasoline.

2.2 National Ambient Air Quality Standard for Fine Particulate Matter

The Clean Air Act requires the U.S. Environmental Protection Agency (EPA) to set National 

Ambient Air Quality Standards (NAAQS) for pollutants considered harmful to public health and 

the environment. There are two categories of NAAQS. The primary standards establish limits to 

protect public health, and the secondary standards protect against environmental and welfare 
2

effects such as decreased visibility and damage to crops, animals, and buildings. Currently, there 

are six pollutants with established NAAQS: carbon monoxide, lead, particulate matter (PM10 and 

PM2.5), sulfur dioxide, nitrogen dioxide, and ozone. These pollutants are referred to as “criteria” 

pollutants. If an area violates a standard, it is classified as a nonattainment area for that specific 

pollutant. The states and/or tribes responsible for the affected area must then develop and 

implement strategies and control measures to attain the NAAQS. The objective for designated 

nonattainment areas is to be reclassified to attainment by the EPA.

The NAAQS for fine particulate matter (PM2.5) was established in 1997. A primary and 

secondary 24-hour standard was set at 65 μg/m3 (micrograms per cubic meter of air), measured 

as the 98th percentile concentration averaged over three years. Primary and secondary annual 

standards were set at 15.0 μg/m3, measured as the annual arithmetic mean averaged over three 

years. 

The CAA requires that the EPA carry out a periodic review of the NAAQS for the criteria 

pollutants. The EPA reviewed the PM2.5 NAAQS during the 2000s and determined based on the 

latest health studies that the 24-hour standard must be strengthened to ensure protection of public 

health. The updated standard of 35μg/m3 was finalized in October, 2006. In 2012, the EPA 

strengthened the primary annual PM2.5 standard to 12 μg/m3, but retained the secondary standard 

of 15.0 μg/m3 and the 2006 24-hour standard of 35μg/m3

.

2.3 Wisconsin’s 2006 PM 2.5 NAAQS Maintenance Area 

Milwaukee, Racine, and Waukesha counties constitute Wisconsin’s 2006 PM2.5 NAAQS 

maintenance area (Figure 1). In 2009, EPA determined that these counties were not meeting the 

2006 24-hour PM2.5 standard. The nonattainment designation for the three-county area in 

Wisconsin was established in a final rule published on November 13, 2009.

In June 2012, the Wisconsin Department of Natural Resources (WDNR) submitted a request to 

EPA to redesignate the three counties from nonattainment to attainment based on monitoring 

data collected between 2008 and 2011. The data showed that PM2.5 concentrations were no 

longer exceeding the levels of the standard. Measurements since 2011 continue to show 

attainment of the standard in the three-county area as well as the rest of the state.

In light of a court decision (Natural Resources Defense Council v. EPA), EPA requested that 

states, including Wisconsin, supplement their redesignation requests with additional information. 

DNR submitted this information in the following document: Supplemental Information for a 

June 2012 Redesignation Request and Maintenance Plan for the 24-Hour Fine Particulate Matter 

National Ambient Air Quality Standard.
3

Figure 1. Wisconsin Maintenance Area under the 2006 PM 2.5 NAAQS
4

On February 18, 2014, EPA published a proposed rule to redesignate the three counties to 

attainment and approve all parts of Wisconsin's maintenance plan, the plan demonstrating how 

the state will ensure continued attainment of the PM2.5 standard. On April 22, 2014, EPA 

published its final approval of the redesignation.

2.4 Transportation Conformity

Transportation conformity is required under CAA section 176 (c) (42 U.S.C 7506(c)) to ensure 

that federally funded or approved highway and transit activities are consistent with – or 

“conform to” – the purpose of the state air quality implementation plan (SIP). “Conform to” the 

purpose of the SIP means that transportation activities will not cause or contribute to new air 

quality violations, worsen existing violations, or delay timely attainment of the relevant NAAQS 

or any interim milestones. Transportation conformity applies to designated nonattainment and 

maintenance areas for transportation-related criteria pollutants: ozone, PM2.5, PM10, carbon 

monoxide, and nitrogen dioxide. EPA’s transportation conformity rule (40 CFRR Parts 51 and 

93) establishes the criteria and procedures for determining whether metropolitan transportation 

plans, metropolitan transportation improvement programs, federally supported highways 

projects, and federally supported transit projects conform to the SIP.

The maintenance plan established motor vehicle emissions budgets (MVEBs) for volatile organic 

compounds (VOCs), sulfur dioxide (SO2), oxides of nitrogen (NOx), and fine particulate matter 

(PM2.5) for the years 2020 and 2025 for use in conducting transportation conformity 

determinations. These budgets were developed based on key motor vehicle parameters that 

reflect the most recent planning assumptions, such as vehicle age distribution, vehicle fuel 

inspection requirements, and maintenance plan requirements. 

The transportation conformity rules require that planning assumptions are “current,” which 

means no older than five years in the case of vehicle age distribution. During the update of the 

dataset to the year 2014, the WDNR, Wisconsin Department of Transportation (WisDOT), and 

Southeastern Wisconsin Regional Planning Commission (SEWRPC) noted a significant 

reduction in the purchase of new motor vehicles beginning in 2008, reflecting the national 

economic recession. This decrease in new car sales resulted in an increase in the average age of 

the vehicle fleet as motorists continued to drive their vehicles longer. Incorporating the 2014 

vehicle age distribution in the MOVES2014 model resulted in an increase in projected emissions. 

During the most recent conformity determination for the SEWRPC region, WDNR determined 

that the difference between the forecasted VOC emissions for the transportation plan and the 

VOC MVEB was only 2 percent. 

Another factor potentially affecting motor vehicle emissions estimates is the travel activity 

outputs from SEWRPC’s travel demand model. These model outputs include miles and hours of 

vehicle travel, categorized by time of day, speed, vehicle type, and facility type. A number of 
5

factors unrelated to changes in the region’s transportation plan and program can affect the model 

output. Thus, changes can occur in emission estimates that do not reflect an actual change in the 

region’s emissions. Such model changes include:

• Updated version of the model software;

• Changes to the network coding outside the region, reflecting choice of which roads to 

include in the model rather than changes to the actual road network;

• Changes in input file generation methods; and

• Changes in modeling methods, such as changes to traffic analysis zones (e.g., 

splitting or combining zones).

Due to the emissions impact of the recent changes in vehicle age distribution, as well as potential 

variability in travel demand model outputs, the WDNR proposes to revise the MVEBs for VOCs 

by allocating safety margin emissions to the budgets, as described in the following section. The 

MVEB revisions will facilitate transportation conformity determinations for the MilwaukeeRacine-Waukesha area while remaining consistent with maintenance of the 2006 PM2.5 standard. 

2.5 Revised Motor Vehicle Emission Budgets for VOCs

One of the critical components of a maintenance plan is the comparison of the area’s emissions 

in the attainment year to those projected for the final year of the maintenance plan. Table 1

compares the 2006 PM 2.5 Milwaukee-Racine-Waukesha Maintenance Plan’s attainment year 

total VOC emissions from point, area, and mobile sources to the emissions projected for the year 

2025. The difference between the two values is referred to as a “safety margin.”

Table 1

VOC Emissions Safety Margin under the 2006 PM 2.5 Maintenance Plan 

2010 Attainment Year 

Emissions

(tons per winter day)

2025 Final Year Emissions 

Projection

(tons per winter day)

Total Safety Margin

 

(tons per winter day)

127.4 106.7 20.7

The EPA transportation conformity regulations (40 CFR 93.124) allow for the use of some or the 

entire safety margin in the development of MVEBs for maintenance plans (58 FR 62188). As 

indicated in Table 1, VOC emissions are projected to be 20.7 tons per day lower in 2025 than 

2010. The WDNR proposes to allocate a portion of the safety margin to the year 2020 and 2025 

MVEBs established in the maintenance plan, as shown in Table 2 below.
6

Table 2

Proposed Revised Motor Vehicle Emissions Budgets for VOCs 

Emission 

Budget Year

Approved 

Emission Budget

(tons per winter day)

Proposed Allocation of 

Safety Margin

(tons per winter day)

Proposed Revised 

Emission Budget

(tons per winter day)

2020 15.890 2.384 18.274

2025 11.980 1.798 13.778

3. Public Participation

In accordance with section 110(a) (2) of the CAA, the WDNR is required to hold a public 

hearing prior to the adoption of this plan and subsequent submittal to the EPA. The Department 

will notify the public and other interested parties of an upcoming public hearing and public 

comment period 14 days prior to holding the hearing as follows:

Notice of availability of the Revision to the Motor Vehicle Emissions Budgets Included in the 

Milwaukee-Racine-Waukesha County Fine-Particulate National Ambient Air Quality (NAAQS) 

Maintenance Areas was posted on the WDNR Air Management website on September 29, 2015: 

http://dnr.wi.gov/topic/AirQuality/Input.html

• The public hearing was scheduled for October 9, 2015 beginning at 1:30p.m. at the 

Wisconsin Department of Natural Resources Building, Conference Room 713, 101 South 

Webster Street, Madison, WI 53707.

• The public comment period for the plan opened when it was posted on the Wisconsin 

Department of Natural Resources Air Management website on September 29, 2014, and 

closes on October 28, 2015, 19 days after the public hearing.
BEFORE THE

DEPARTMENT OF NATURAL RESOURCES

Notice of Public Hearing

Revision to the Wisconsin State Implementation Plan (SIP)

Proposal to Adjust the Motor Vehicle Emissions Budgets (MVEB)

For the Milwaukee-Racine-Waukesha 2006 24-Hour Fine Particulate Maintenance Area

NOTICE IS HEREBY GIVEN that pursuant to ss. 285.11(5) and (6) and 285.23(2) and (4), Wis. Stats., 

and ch. NR 401, Wis. Adm. Code, the Wisconsin Department of Natural Resources (WDNR) will hold 

public hearing on its proposed adjustment to the MVEB for or the Milwaukee-Racine-Waukesha 

maintenance area for the 2006 24-hour National Ambient Air Quality Standard (NAAQS) for fine 

particulate matter (PM 2.5).

Date and Time Location

October 9, 2015 State Natural Resources Building (GEF II)

1:30 PM Room 713

101 South Webster Street

Madison, Wisconsin 53703

Reasonable accommodations or informational material in an alternative format will be provided for 

qualified individuals with disabilities upon request. To do so, make a request to Mr. Mike Friedlander 

using the contact information provided below. A request must include specific information and be 

received at least 10 days before the date of the scheduled hearing.

Availability of the Proposed SIP Documents

Background information and proposed documents related to the proposed adjustment to the MVEB for

Milwaukee-Racine-Waukesha maintenance plan can be downloaded at 

http://dnr.wi.gov/topic/AirQuality/Input.html or hard copies, free of charge, by contacting Mr. Mike 

Friedlander below.

Background

The U.S. Environmental Protection Agency (EPA) approved Wisconsin’s request to redesignate the 

Milwaukee-Racine-Waukesha nonattainment area to attainment for the 2006 24-hour NAAQS for fine 

particulate on April 22, 2014 [79 FR 22415]. This redesignation approval established transportation 

conformity MVEB for the years 2020 and 2025. The maintenance plan revision establishes new Volatile 

Organic Compound (VOC) MVEB for the years 2020 and 2025. The Department is proposing the 

allocation of a portion of the safety margin for VOCs to the area’s 2020 and 2025 MVEB for 

transportation conformity purposes. This allocation will still maintain the total emissions for the area at or 

below the attainment level required by the transportation conformity regulations while providing for 

transportation growth. The transportation conformity budget for oxides of nitrogen (NOx), Sulfur Dioxide 

(SO2), direct PM 2.5 will remain the same as the previously approved MVEB in the maintenance plan.

Action Subject to Comment

The Department is soliciting comment on all elements regarding to the proposed adjustment to the MVEB

for or the Milwaukee-Racine-Waukesha maintenance area for the 2006 24-hour National Ambient Air 

Quality Standard (NAAQS) for fine particulate matter (PM 2.5).

Agency Contact and Submitting Comment

Comments on the proposed MVEB adjustment for Milwaukee-Racine-Waukesha maintenance plan 

should be received on or before October 28, 2015. Written comments may be submitted by U.S. mail, 

fax, or email and will have the same weight and effect as oral statements presented at the public hearing.
Questions or requests related to the hearing and written comments or questions on the proposed 

maintenance plan adjustment SIP should be submitted to:

Mr. Mike Friedlander

Department of Natural Resources

Bureau of Air Management (AM/7)

101 S. Webster Street, P.O. Box 7921, Madison WI 53703-7921

Phone: (608) 267-0806

Fax: (608) 266-0560

E-mail: Michael.friedlander@wisconsin.gov

Dated at Madison, Wisconsin __09/22 /2015_______________________ 

STATE OF WISCONSIN

DEPARTMENT OF NATURAL RESOURCES

By - /s/ Andrew M. Stewart 

Andrew M. Stewart

Deputy Director

Bureau of Air Management 
1

DATE: December 22, 2015 

TO: File 

FROM: Mike Friedlander, AM/7 

SUBJECT: Revision to the Wisconsin State Implementation Plan (SIP); Proposal to Adjust the Motor 

Vehicle Emissions Budgets (MVEBs) for the Milwaukee-Racine-Waukesha 2006 24-Hour 

Fine Particulate Maintenance Area 

This memo confirms that the Wisconsin Department of Natural Resources (WDNR) held a public hearing 

on October 9, 2015 at 1:30 PM in the State Natural Resources Building, Room 713, 101 South Webster 

Street, Madison, WI 53703. The WDNR solicited comments regarding the proposed adjustment to the 

MVEB for the Milwaukee-Racine-Waukesha maintenance area for the 2006 24-hour National Ambient 

Air Quality Standard (NAAQS) for fine particulate matter (PM 2.5). 

The public comment period for the proposed adjustment to the MVEB for the Milwaukee-RacineWaukesha maintenance area for the 2006 24-hour PM2.5 NAAQS closed on October 28, 2015. No public 

comments were received during the public comment period. 

State of Wisconsin CORRESPONDENCE/MEMORANDUM