Commonwealth of Pennsylvania

Department of Environmental Protection

FINAL

State Implementation Plan Revision:

Diesel-Powered Motor Vehicle Idling Act

(Act 124 of 2008)

January 2010

Bureau of Air Quality

Pennsylvania Department of Environmental Protection

P.O. Box 8468

Harrisburg, PA 17105-8468

717-787-9495

www.depweb.state.pa.us

(Blank for two sided copying)Pennsylvania State Implementation Plan
Revision to Incorporate the Diesel-Powered Motor Vehicle Idling Act (Act
124 of 2008)

Purpose of Document

The purpose of this document is to request that the U.S. Environmental
Protection Agency (EPA) incorporate the Diesel-Powered Motor Vehicle
Idling Act (Act 124 of 2008) into the Pennsylvania State Implementation
Plan (SIP).  The emission reductions achieved by imposing restrictions
on the idling of diesel-powered motor vehicles with a gross weight (GW)
equal to or greater than 10,001 pounds will allow the Commonwealth to
make progress in attaining and maintaining National Ambient Air Quality
Standards (NAAQS) including the health-based 

eight-hour ozone and fine particulate standards.  

If Act 124 is incorporated into the Pennsylvania SIP, it will become
enforceable by EPA, in addition to continuing to be enforceable by state
and local governmental entities.  Pennsylvania will also be able to take
credit in subsequent SIP revisions for emission reductions resulting
from compliance with Act 124. 

Overview of Act 124

On October 9, 2008, Governor Rendell signed the Diesel-Powered Motor
Vehicle Idling Act (Act 124 of 2008; P.L.1511, No. 124); the law became
effective on February 6, 2009.  The act, codified at 35 P.S. §§ 4601-
4610, will reduce unnecessary idling of the main propulsion engine in
diesel-powered motor vehicles, including trucks and buses.  Act 124
prohibits the owners and drivers of any diesel-powered motor vehicle
with a gross weight of 10,001 pounds or more, engaged in commerce, from
allowing or causing the engine of the vehicle to idle for more than five
minutes in any continuous 60-minute period, except as provided in the
act.  In addition to vehicle drivers and owners, owners and operators of
locations where subject vehicles load, unload or park are also
responsible for compliance with Act 124. 

Buses, school buses and school vehicles may idle for 15 minutes in a
continuous 60-minute period when passengers are aboard.  Other
exemptions address excess idling due to factors outside the drivers’
control, such as traffic or mechanical issues.  There are also
exemptions addressing idling during maintenance, vehicle equipment
inspection, and emergency or utility service functions, and idling for
security reasons.  Certain types of other vehicles including motor
homes, commercial implements of husbandry, implements of husbandry, farm
equipment, and farm vehicles are not covered by Act 124.  Additionally,
the restriction on idling does not apply if a vehicle exhibits a label
issued by the California Air Resources Board under 13 CCR
§1956.8(a)(6)(C) showing the vehicle’s engine meets the optional
nitrogen oxide (NOx) idling emission standard.

An owner or operator of a location where subject vehicles load or
unload, or where 15 or more parking spaces are provided for vehicles
subject to the act, must erect and maintain at least one permanent sign
to inform drivers that idling is restricted in Pennsylvania.  The
requirements of the law will not be incorporated into any permit issued
by the Department of Environmental Protection (DEP).  

Any conviction for violations of Act 124 will result in fines ranging
from $150 to $300, plus court costs.  DEP is also authorized to assess
civil penalties, not to exceed $1,000 per day for each violation of Act
124.  Although Act 124 preempts and supersedes local anti-idling
ordinances or rules, more stringent idling restrictions imposed by
counties of the first and second class (Allegheny and Philadelphia
counties) prior to Jan. 1, 2007, continue in full force and effect
provided they are not amended, suspended or rendered invalid.  See
Appendix A of this document for a copy of the law.  

Benefits of Act 124

Act 124, which requires idling reduction by diesel-powered vehicles over
10,000 pounds gross weight, will help reduce emissions of pollutants
that contribute to ground-level ozone and fine particulate matter
concentrations.  Projected emission reductions, assuming at least a 50%
compliance rate, are shown below in Table 1 for volatile organic
compounds (VOC), nitrogen oxides (NOx) and fine particulate matter
(PM2.5).

Table 1: Projected Emission Reductions from Act 124

(tons per year)

	2009	2018

VOC	45	30

NOx	1622	1600

PM2.5	30	7



In 1997, the EPA established ozone and PM2.5 primary and secondary NAAQS
to be more protective of public health and the environment than earlier
ozone and particulate matter standards and to ensure an adequate margin
of safety.  In October 2006, EPA further tightened the 24-hour PM2.5
standard, and in March 2008, EPA strengthened the ground-level ozone
standards.  In September 2009, EPA announced that it will reconsider the
2008 ozone standard in order to ensure the standard is clearly grounded
in science, protects public health with an adequate margin of safety,
and is sufficient to protect the environment.  

Fine particles or PM2.5 (particles with a diameter of 2.5 micrometers or
less) in the atmosphere are made up of a complex mixture of components. 
Some, like diesel particulate, are emitted directly into the air
(primary sources) and others, such as sulfate and nitrate, form in the
air as a result of various chemical reactions (secondary sources).  The
health effects associated with exposure to PM2.5 are significant, and
the evidence for these effects is compelling.  Premature mortality,
aggravation of existing respiratory and cardiovascular disease,
decreased lung function and asthma attacks have been attributed to
exposure to PM2.5.

Ground-level ozone is not emitted directly to the atmosphere but is
formed by a photochemical reaction between VOCs and NOx in the presence
of sunlight.  Heavy-duty vehicles contributed about 25% of all NOx
emissions in this Commonwealth in 2002.  (Compared to gasoline-powered
vehicles, diesel vehicles are not a significant source of VOCs.) 
Repeated exposure to ozone pollution may cause a variety of adverse
health effects for healthy people and those with existing conditions,
including difficulty in breathing, chest pains, coughing, nausea, throat
irritation and congestion.  It can exacerbate bronchitis, heart disease,
emphysema, and reduce lung capacity.  Ozone can aggravate asthma,
causing more asthma attacks, increased use of medication, more medical
treatment and more frequent visits to hospital emergency clinics.  Ozone
also has adverse effects on vegetation (forests and food crops) and,
through deposition of NOx precursors, contributes to pollution in the
Chesapeake Bay.

Furthermore, EPA and other agencies have evaluated the health effects of
direct exposure to diesel particulate matter.  The small size of diesel
exhaust particles allows them to be drawn deeply into the lungs.  Diesel
particulates are, for the most part, even smaller than 2.5 micrometers. 
The EPA has said that long-term exposure to diesel particulate exhaust
is likely to pose a lung cancer hazard.  Exposure to diesel particulates
has non-cancer and acute effects as well, including throat and eye
irritation and inflammation, exacerbation of existing respiratory and
allergic conditions, and exacerbated risk of heart attacks.  Studies
indicate that children living near highways have more lung and breathing
problems than other children.  Children may also be exposed to more
diesel exhaust inside diesel school buses, especially in idling buses
that queue.  People commuting to work in almost any mode of
transportation along truck routes are exposed to high levels of diesel
fine particulate matter.

Vehicle operators, the people in the closest proximity to diesel
exhaust, will benefit most, particularly drivers of long-haul vehicles. 
In addition to cleaner air, the noise of their sleeper berth should
decrease if power is supplied by an alternative power source.  This
should lead to a more rested truck driver.  The National Transportation
Safety Board has cited fatigue as a major cause of accidents in which
long-haul trucks are involved.  Nearly 500,000 trucks in the nation are
dedicated to long-haul trips.  Since trucking companies need to replace
truck drivers constantly due to high turnover rates, more truck
operators would be affected than there are number of trucks.  It is
possible that most, if not all, long-haul drivers will idle in this
Commonwealth at some time.  Including bus drivers and local drivers in
this Commonwealth, there are nearly one million drivers who may benefit
through reduced exposure to diesel emissions.

In addition, because idling heavy-duty vehicles consume approximately
one gallon of fuel per hour, reducing idling will save diesel vehicle
owners and operators money over the long run.  Because the United States
increasingly relies on imported fuel for transportation needs, reducing
idling will contribute to the country's energy independence.  Another
benefit of reducing idling is the reduction of carbon dioxide (CO2)
emissions, a major greenhouse gas.  Idling heavy-duty diesel vehicles
can produce as much as 22.2 pounds of CO2 for every hour of idling time.


Public Comment

Requirements for a public comment process are set forth in Section
110(a)(2) of the CAA and 40 CFR Section 51.102(d).  Public hearings on
the incorporation of Act 124 into the Pennsylvania SIP were held in
Harrisburg on September 17, 2009, and in Norristown and Pittsburgh on
September 18, 2009.  Notice of the hearings was published in the
Pennsylvania Bulletin on August 15, 2009, and in newspapers in general
circulation at least 30 days prior to the date of the hearing.  The
public comment period ended on Friday, September 25, 2009.  A
comment/response document has been developed and is being submitted to
EPA with this final SIP revision.  

Appendix A

ACT 124

Diesel-Powered Motor Vehicle Idling Act

(P.L. 1511, No. 124)

 PAGE   

  PAGE  2 

Incorporation of Act 124: SIP Revision

John Hanger

Secretary

Edward G. Rendell

Governor

