A Case Study of Fuel Use and Emissions of Non-Road Construction Equipment.

ABSTRACT

MARSHALL, STEVEN. A Case Study of Fuel Use and Emissions of Non-Road

Construction Equipment. (Under the direction of Dr. William Rasdorf).

Construction of commercial buildings has a significant environmental impact and a large part

of this impact is due to emissions from nonroad equipment. Construction produces 7 percent

of the US greenhouse gas emissions and 76 percent of that is from engines. Therefore,

determining where and when construction produces emissions is an important next step.

Continual improvements in other industry sectors mean construction too needs to continue to

improve its emissions reduction efforts. Thus, emissions inventories (i.e. databases of project

emissions by type, cost, etc.) need to be developed to quantify these emissions for further

study. The emissions addressed in this paper include CO

, NO

, THC, CO, PM, and SO

.

This thesis outlines one process for determining emissions from nonroad construction

equipment engines performing typical construction activities. The thesis presents a

methodology that provides a direct link between construction activities and emissions. It also

demonstrates the use of this methodology on a building case study, thereby providing

quantified emissions predictions for various levels of detail of the project (i.e. activity,

division, project) work breakdown. Using this methodology both fuel use and emissions can

be determined at any stage of the planning-design-build process with increasing levels of

precision being obtained as the project progresses. Key findings include the presence of

To identify the relevance this research has on the construction industry a connection is made

between the methodology and construction equipment fuel use. As an extension of this

connection emissions and fuel use data were developed in a time based format to parallel

with construction scheduling and resource allocation which both are common techniques

used in the construction industry. These industry connections serve to make the products of

A Case Study of Fuel Use and Emissions of Non-Road Construction Equipment

by

Steven Kelly Marshall

A thesis submitted to the Graduate Faculty of

North Carolina State University

in partial fulfillment of the

requirements for the degree of

Master of Science

Civil Engineering

Raleigh, North Carolina

11/29/10

APPROVED BY:

_______________________________ ______________________________

William

Rasdorf

Michael

Leming

Dedication

This work is dedicated to my family and specifically my parents. Without their support and

encouragement through school and college I would not be where I am today. My family has

been my foundation throughout life and I express my sincere thanks to them.

Biography

Steven Kelly Marshall was born and raised on the eastern shore of Maryland near the town of

Cambridge. He graduated from Cambridge South Dorchester High School in Dorchester

County, Maryland. Kelly went on to graduate Cum Laude with his Bachelors of Civil

Engineering from University of Delaware in the spring of 2008. He continued his studies at

North Carolina State University in the fall of 2008, seeking his Master’s of Science in

Construction Engineering and Management.

Kelly has worked each summer since his sophomore year of college seeking valuable

experience as an engineering intern. He began his internship experiences with the Delaware

Department of Transportation working in road and highway design. From there he

proceeded into construction inspection and began working with an engineering consultant,

Rummel, Klepper and Kahl (RK&K). When he moved to Raleigh, North Carolina he

continued working for RK&K in the Raleigh design division.

Kelly is a member of numerous academic organizations including Tau Beta Pi, National

Engineering Honor Society as well as Chi Epsilon the National Civil Engineering Honor

Acknowledgements

I would like to thank my advisor, William Rasdorf, for his guidance and expertise in helping

me develop this research. I would also like to thank Phil Lewis for his support and for

providing the groundwork which led to the ideas for this research.

I would like to acknowledge my committee members, Dr. Leming and Dr. Frey for providing

their time and expertise during the presentation and review of this research.

I would also like to acknowledge Reed Construction Data for providing their cost data (RS

Means) free in the form of RS Means CostWorks. This software and associated cost data

were integral to this research.

Table of Contents

LIST OF TABLES ... vii

LIST OF FIGURES ... viii

1.0 

INTRODUCTION...1 

1.1 

Problem ...3 

1.2 

Research Objective ...4 

2.0 

SCOPE ...5 

2.1 

Included and Excluded Vehicles and Equipment ...6 

3.0 

BACKGROUND AND LITERATURE REVIEW ...7 

3.1 

EPA Sector Strategies Report ...9 

3.2 

Colorado State University Study - CEDST ...13 

3.3 

EPA/MRI Studies ...17 

3.3.1 

Particulate Emissions from Construction Activities ...17 

3.3.2 

Mud/Dirt Carryout as Particulate Emissions ...20 

3.3.3 

Study Comparisions ...22 

3.4 

Carnegie Mellon Study ...23 

3.5 

University of Illinois Urbana-Champaign Research ...28 

3.6 

North Carolina State University Research ...31 

4.0 

MODELS USED IN RESEARCH ...35 

4.1 

NONROAD Model ...35 

4.2 

RS Means Cost Data ...36 

4.2.1 

CSI Divisions ...39 

5.0 

METHODOLOGY ...40 

5.1 

Selecting the Case Study ...40 

5.1.1 

Case Study Description ...41 

5.2 

Quantity Take Off and Cost Estimate ...43 

5.3 

Emissions Factors...46 

5.4 

Activity Level Emissions Analysis ...49 

5.4.1 

Selecting Equipment ...51 

5.5 

Time Based Emissions Analysis ...53 

5.6 

Fuel Usage ...55 

6.0 

RESULTS ...56 

6.1 

Cost Estimate ...56 

6.1.1 

Comparison of Costs ...60 

6.1.2 

Reconciliation of RS Means Estimate ...61 

6.1.3 

Validation and Use of Estimate ...65 

6.2 

Emissions Data ...66 

6.2.1 

Activity Level Emissions ...66 

6.2.2 

Division Level Emissions ...69 

6.2.4 

Time Based Emissions ...72 

6.3 

Fuel Usage Analysis ...77 

7.0 

CONCLUSIONS ...79 

7.1 

Activity Emissions ...79 

7.2 

Division Emissions ...80 

7.3 

Time Based Emissions ...81 

7.4 

Fuel Consumption ...84 

8.0 

RECOMMENDATIONS ...85 

8.1 

Activity Emissions ...85 

8.2 

Division Emissions ...86 

8.3 

Time Based Emissions ...87 

8.4 

Fuel Consumption ...90 

9.0 

REFERENCES ...91 

List of Tables

Table 1-1 Example EPA Engine Tier Classification [EPA, 2004] ... 2 

Table 2-1 Vehicle/Equipment List ... 7 

Table 3-1 On Highway Truck Usage ... 25 

Table 3-2 Activity Modes for Construction Equipment ... 33 

Table 4-1 CSI Division Identification Table ... 39 

Table 5-1 NONROAD Emission Factors for Crawler/Dozers ... 48 

Table 5-2 Equipment Requiring Horsepower Information ... 52 

Table 5-3 Example Analysis Table Layout ... 52 

Table 6-1 Division Cost Comparison ... 58 

Table 6-2 Sample Calculation of Total CO

Emissions Estimates for the Concrete Division

... 67 

Table 6-3 Emissions per Division (in Pounds) ... 70 

Table 6-4 Emissions per Division (Percent) ... 71 

Table 6-5 Total Project Emissions by Pollutant ... 71 

List of Figures

Figure 4-1 CostWorks Item Selection Window ... 37 

Figure 4-2 CostWorks Quantity Input Field ... 38 

Figure 4-3 Costworks Item List ... 38 

Figure 5-1 Case Study Diagram ... 43 

Figure 6-1 Means vs. SDI Correlation Graph ... 59 

Figure 6-2 Week 7 Scheduled Activities with Associated CO

Emissions ... 73 

Figure 6-3 Cumulative Frequency Diagram for Emissions over Project Duration ... 75 

Figure 6-4 Weekly CO

Emissions over Project Duration ... 76 

1.0

INTRODUCTION

Commercial building projects are a significant source of energy use and waste. Existing

research has studied the various aspects of construction’s environmental impact including life

cycle analysis, sector wide emissions, experimental emissions measurement, management

methods and techniques, cap and trade policies, and regulations. Emissions from diesel

engines are a key air-related contributor to the environmental impact associated with

construction. Construction of all types depends heavily on the use of diesel powered

vehicles. Onroad diesel emissions have been studied and regulated and for many years;

concern is now growing over nonroad, diesel powered engines [Millstein, 2009], especially

in light of their greenhouse gas production rate.

Engine emissions are a significant source of CO

and other pollutants (NO

, THC, CO, PM,

and SO

) and merit significant study [EPA, 2009a]. Nonroad engines are of particular

interest because until recently, regulations for them were not as strict as for onroad vehicles.

Nonroad engines are now regulated using a tier 1 to tier 4 classification system. Table 1-1

depicts an example engine tier classification for engines between 50 and 75 horsepower,

similar standards exists for all other horsepower ranges. Currently, manufactured engines

must meet tier 4 requirements which, when fully implemented, will bring their emissions in

line with onroad vehicles [EPA, 2009b]. However there still exists a large fleet of older

equipment which produces more emissions than do newer models. Since fuel use and

use as one means to reduce emissions, especially for older equipment. It is also important to

know what emissions a construction project will produce and what construction processes are

significant emissions contributors in order to develop emissions management strategies for

the long term. This paper addresses these topics.

Table 1-1 Example EPA Engine Tier Classification [EPA, 2004]

Engine Horsepower

(HP)

Model

Years Regulation

Emission Standards (g/hp-hr)

HCa NMHC

+ NOx CO NOx PM

50 ≤ HP < 75

1998 – 2003 Tier 1 NS NS NS 6.9 NS

2004 – 2007 Tier 2 NS 5.6 3.7 NS 0.30

2008 – 2012 Tier 3 NS 3.5 3.7 NS 0.22

2008 – 2012 Tier 4 Transitional b NS 3.5 3.7 NS 0.22

2013 + Tier 4 Final b NS 3.5 3.7 NS 0.02

NS = No Standard a

Tier 4 standards are in the form of non-methane hydrocarbons (NMHC). b

The Tier 3 NOx standard of 3.5 g/hp-hr was implemented beginning in 2008. The Tier 4 Transitional standard also begins in 2008, leaving the Tier 3 NOx standard unchanged but adding a 0.22 g/hp-hr PM standard.

A study by Colorado State University sought to create a tool to assess the impact of the

construction phase [Guggemos and Horvath, 2006] but the result was a set of tables that was

separate and different from any standard industry accepted practice. This tool required a

great deal of knowledge regarding the means and methods of construction which meant that

the average designer would find it difficult to use without consulting the contractor. Other

studies focused on specific aspects of the environmental impacts such as dust and dirt as

use and specifically fuel use which directly effects engine emissions but did not suggest a

process to estimate emissions.

1.1

Problem

The results of a study to develop a tool to determine construction project emissions which

refers to the six primary Environmental Protection Agency (EPA) recognized air pollutants,

CO, CO

, NO

, SO

, THC and PM, that can be easily integrated into conventional

construction management tools, are discussed in this report. Other environmental impacts

associated with construction projects such as waste and any impact from fabrication are not

included in this analysis. This study makes use of an industry standard estimating tool, RS

Means [Means, 2009], to develop an activity by activity cost estimate and with that assign

emissions to each activity.

This study intends to solve one of the current problems in quantitatively and practically

assessing the emissions impact of construction projects. Much of the environmental focus

regarding construction remains on building’s life cycle impacts, which is typically addressed

by the United States Green Building Council’s (USGBC) Leadership in Energy and

Environmental Design (LEED) certifications. This program emphasizes reducing the life

cycle impact of the building from electrical and water usage to ergonomics, with little to no

attention to means of construction. Thus far there have only been a few unsuccessful

non-road engine emissions. Furthermore only one other attempt at estimating project impact was

found using only data available prior to construction.

Another challenge with estimating emissions is that, unlike estimating project cost,

knowledge of the construction means and methods are needed. For this reason it is important

to use a cost estimating tool that links construction activities to construction means and

methods. The challenge with this requirement is the most likely entity to perform these

estimates is the design engineer or architect however the Designer of Record (DOR) typically

avoids specifying or providing any stipulations on construction means and methods. This is

mainly due to the liability presented by outlining a process or dictating means or methods.

Designers are generally not familiar enough with construction, and contractors may have

several different approaches from which to choose. The use of RS Means provides a tool

that can provide a link between cost and process.

1.2

Research Objective

The objective is to provide a method to quantify emissions from construction projects during

the design phase. The focus will be on nonroad construction equipment. Although fuel

usage is one method currently used to quantify emissions and is relatively accurate [EPA,

2009a], it is a post project completion method. The goal of this research is to develop a tool

faceted tool can be used to produce emissions estimates at various stages of the design, from

conceptual through final design.

The results of the research presented here describe a method to estimate pollutant emissions

of a construction project at various points in the design phase, including concept, preliminary

and final design. Based on that assessment, key emissions related project activities and

phases can then be identified.

2.0

SCOPE

This thesis is an extension of the studies conducted by Lewis, Frey, and Rasdorf [2009a] and

describes a method to quantify construction project pollutant emissions at activity, division,

and project levels. The work does not extend to a life cycle analysis of a project but involves

on construction activities performed on site necessary to complete construction of the project.

The research does not address emissions from fabrication, materials production, equipment

production, electricity use on site, or any task performed outside the confines of the

construction site. Additionally it addresses only the six primary pollutants (CO

, NOx, THC,

CO, PM, and SO

) and does not account for other environmental impacts such as waste,

heavy metals, runoff, or sediment.

Emissions reported herein are based on equipment identified in the RS Means crew lists.

vehicles because of the difficulty in quantifying their use allocation on a project by project

basis. Thus, this study specifically disregards any transport of materials or supplies that

occurs via onroad vehicles such as flat bed trucks or dump trucks. Although other research

suggests this is a valid assumption, some onroad vehicles used on a site will clearly be

emissions contributors [Guggemos and Horvath, 2006]. The method developed and

described in this thesis seeks to be straightforward and simple to allow maximum use within

the construction industry in both practice and additional research.

This thesis refers to emissions as being derived from an internal combustion engine. As

discussed, later there are other sources of pollutant emissions. These sources are important

but they are separate from engine-based pollutants and they are not addressed herein. The

case study used in this study is a church, a commercial construction project. The case study

includes all activities normally associated with this type of construction and utilizes typical

activity durations, costs, and crew compositions.

2.1

Included and Excluded Vehicles and Equipment

Labor, vehicles and other equipment where selected from the RS Means established crews.

Emissions were estimated for these crews and used to estimate emissions for each

construction activity. Due to the scope limitations outlined above, certain vehicles were

equipment with engines such as a concrete pumps, and heavy lifting equipment such as

cranes were all included in the emissions inventory. The only two vehicles or equipment

identified by RS Means that were excluded from the emission inventory were two flatbed

trucks (one 1.5 and one 3 ton). These vehicles are designed for and used primarily on the

road and thus are bound by different emissions standards and regulations. The focus of this

study was on equipment used entirely on the construction site. A complete list of all of the

included and excluded equipment for the case study is presented in Table 2-1.

Table 2-1 Vehicle/Equipment List

Included Vehicles/Equipment

A.T. Forklift, 42' lift

Gas Engine Vibrator

Air Compressor, 160cfm

Grader, 30,000 Lbs.

Asphalt Paver, 130 HP

Hyd. Crane, 12 Ton

Backhoe Loader, 48 HP

Hydraulic Excavator, 1 C.Y.

Bruch Chipper, 12", 130 H.P.

Loader, Skid Steer, 30 H.P. gas

Chain Saw, Gas, 36" long

Loader-Backhoe

Concrete Pump (small)

Roller, Vibratory, 25 ton

Concrete Saw

S.P. Crane, 4x4 5 ton

Crawler Loader, 3 C.Y.

Skid Steer Loader, 78 H.P.

Curb/Gutter Paver, 2 Track

Tandem Roller, 10 Ton

Dozer, 105 HP

Trowel, 48" Walk-Behind

Dozer, 200 HP

Truck Tractor, 6x4, 450 HP

Dozer, 300 HP

Vibrating Roller, Towed, 12 ton

F.E. Loader, W.M., 2.5 C.Y.

Excluded Vehicles

Flatbed Truck, Gas, 1.5 Ton

Flatbed Truck, Gas, 3 Ton

3.0

BACKGROUND AND LITERATURE REVIEW

Air pollution is a serious concern and vehicle emissions are a significant source of air

source of Greenhouse Gases (GHG) and seeks to reduce them using various methods [EPA,

2009a]. Greenhouse gases, when discussing construction, refers only to CO

from fossil fuel

combustion [EPA, 2009a]. Carbon dioxide as well as the other pollutants mentioned above

are the main focus of the research in this paper because they are the main pollutants from

engine emissions. Diesel engines also emit particulate matter which is attributable to health

concerns [EPA, 2009b]. The other four pollutants studied in this research, CO, NO

, THC,

and SO

, are also important contributors to pollutant as identified by the EPA [EPA, 2005].

Currently there is only limited research directed at quantifying emissions from construction

equipment on a project level. Most research is directed at sector wide emissions and

environmental impact which is important, but construction is very diverse and emissions can

vary significantly from one sub-sector to another. An example of this would be drywall

installation versus highway and road construction where highway and road construction is on

the order of 19 times more emissions intensive than drywall installation [EPA, 2009).

Although these are two extremes within the construction sector, they serve to illustrate the

potentially large variations that can occur. Therefore, a sector wide emissions and impact

analysis does not provide the insight to allow for reductions at the micro level.

Although nonroad vehicles and equipment are not solely diesel powered, diesel engines “are

relative to onroad vehicles, new rules that provide for the reduction in emissions have been

put in place by the EPA. While the CO

(a GHG) from these engines contributes to global

warming two other pollutants pose a serious health risk, these are Particulate Matter (PM)

and Nitrous Oxides (NO

). These are both linked to serious health problems especially in

children and the elderly where they can cause breathing problems and asthma [Lewis et al.,

2009]. The new emissions standard (which will be implemented in two phases, the first

beginning in 2010) will significantly reduce NO

and all but eliminate PM. This standard is

referred to as Tier 4 which is part of the EPA’s engine tier regulation system which began in

1994 with Tier 1. Although engine regulations will not affect existing engines and

equipment, the fuel regulations that are also a part of the new standard will provide

immediate reductions in PM because the new fuel regulations require a 99% reduction in

sulfur content. [EPA, 2009b]

3.1

EPA Sector Strategies Report

The EPA Sector Strategies division has identified the construction sector as an area for

potential reduction of greenhouse gases. In the report by the EPA, there are two components

to the construction sectors GHG emissions, fossil fuel combustion and purchased electricity.

According to the EPA, the third component of GHG emissions, non-combustion sources, are

insignificant contributors within the construction sector, although significant in other sectors.

The combined total, although dramatically less than Oil and Gas and Chemical sectors, is

76% of the GHG emissions from the construction sector which also is the third highest of all

sectors. This component is significantly higher than those sectors below it on the list. [EPA,

2009a]

The EPA also compares these emissions using emissions intensity which is the emissions per

dollar of value added. The EPA determines the value added based on the gross domestic

product (GDP). Although construction is third in GHG emissions, it has the lowest

emissions intensity according to the data presented by the EPA which was based on 2002

GDP and emissions data. Although having the lowest emissions intensity is not necessarily

bad, it does not represent the entire picture completely. A lower emissions intensity may

mean that a sector has a larger economic output in relation to its emissions output. However,

it does not mean that its emissions output is small. Therefore according to the EPA it is

important to study both total pollutant emissions and emissions intensity because both

provide valuable input into the sources and distribution of emissions. [EPA, 2009a]

EPA projections for the construction sector indicate that GHG emissions will not return to

2005 levels by 2030, however they will continue to increase slightly from current levels. The

average annual increase for construction, although small, was predicted to be the highest

The EPA identified several areas in which contractors have significant control and are key to

reducing overall project emissions. When discussing the emissions due to fossil fuel

consumption, the key to reducing emissions is to reduce fuel consumption. In order to

reduce fuel consumption, the EPA identified 4 areas that contractors could address relating to

the use of off highway equipment. These were equipment idling, maintenance and fuel

selection. The motivation to reduce fuel consumption however is not very strong in most

cases due largely because the cost of fuel in comparison to total operating costs has

historically been relatively small although that ratio is changing with increased fuel costs in

recent years. [EPA, 2009a]

Engine idling is an important means to reduce fuel use and emissions and many states

already have adopted laws to restrict idling times. Idling not only wastes fuel and produces

emissions it can also reduce engine life because each hour of idling can reduce engine life by

up to 2 hours especially if the optimum combustion temperature is not reached. In some

cases it has been found that heavy duty diesel trucks idle an average of 29.4% of their service

life. Additionally it was found that a reduction in idling of 10 hours per month per firm

could save about 1.4 billion pounds of CO

per year. This would also equate to a reduction

in fuel consumption as both emissions and fuel consumption are directly linked.

Operators of equipment can also produce significant reduction if skilled and knowledgeable

regarding the operation of their respective equipment. An example of this would be an

excavator operator attempting to lift more than the capacity of the equipment. If this practice

were eliminated for an hour each day the savings could amount to 225 gallons of fuel or

slightly over 5,000 pounds of CO

. Additionally, planning the construction process more

efficiently can help reduce fuel consumption and thereby emissions as well. A relatively

simple example of this would be reducing the swing angle of an excavator from excavation

to dump from 90 to 30 degrees could save up to 3% of fuel use for that task. [EPA, 2009a]

Equipment maintenance has an effect on fuel use as well. Properly maintained equipment

according to the EPA [EPA, 2009a] will often result in fuel savings but the amount depends

largely on the type of equipment. A significant example of this would be maintaining

properly inflated tires, since underinflated tires increase rolling resistance and thereby fuel

consumption and emissions. Not only is maintenance of equipment important, the proper

size of equipment is also important. Equipment that is undersized will need to work much

harder and be less efficient then a properly sized piece of equipment. The opposite is also

true, oversized equipment will consume more fuel than needed for a given task. This savings

would be specific to individual firms and tasks, and is hard to quantify. Replacing or

repowering equipment is another method to reduce emissions by both reductions in fuel use

the current EPA emissions standards for specific tiers. Older equipment can be retrofitted to

improve efficiency and provide emissions reductions. [EPA, 2009a]

The EPA identified other areas where changes in current practices could lead to reductions in

GHG emissions. Some of these related to fuel use include using biofuels, finding alternatives

to diesel generators and finding ways to reduce employee commuting. Another area of

importance is conservation of electricity as well as reducing the impact of the materials used

on a construction site. [EPA, 2009a]

3.2

Colorado State University Study - CEDST

A study by Colorado State University focused on developing a tool to identify the effect of

the construction phase of a commercial building. The study recognized the lack of valuable

information concerning the environmental impact of construction. The construction phase

represents a small portion of the life cycle environmental impact, only up to 12%. However

the study points out that as buildings become more energy efficient the effect of the

construction phase becomes more and more pronounced. [Guggemos, 2006]

Other aspects of commercial buildings have been studied mostly due to the heavy focus on

Leadership in Energy and Environmental Design (LEED). The CEDST study sought to

preliminary design. The study identified equipment usage for the construction process based

on RS Means. The equipment and their properties were listed in tables and from that the

emissions were calculated. [Guggemos and Horvath, 2006]

The CEDST study also incorporated the impact of fabricated materials such as steel and

includes the estimated construction waste. The goal with this study was to enable designers

to modify their designs based on the environmental impacts of various designs. Researchers

developed the Construction Environmental Decision-Support Tool (CEDST) to estimate

construction project emissions. This tool requires a detailed analysis of the project as it will

be constructed. CEDST is for commercial building construction and is self-contained. The

tool requires the user to input such things as project location, temporary construction

materials and equipment use and waste factors. Since transport and fabrication are included

in this tool, information about both of these is also required as part of the estimating process.

For the case study used in this research, required inputs were derived from 90% complete

plans and estimate. Researchers used RS Means to provide insight on means and methods of

construction. [Guggemos and Horvath, 2005 and 2006]

This study has some key similarities to the current research, including the primary goals.

They both seek to develop a tool for assessing the environmental impacts of construction

commonly used commercial building equipment and utilizes a division (and subdivision)

break down to further identify equipment use; conversely in this study the emissions are

estimated by construction activity. Both studies make use of a single case study to

demonstrate the methodology. In the Colorado State University research the case study is

very narrow being only construction of the structure of a commercial building. However,

this research sought to use a case study that encompassed a wide variety of work.

Additionally both made use of the EPA’s NonRoad Model for assigning emissions to

construction equipment and vehicles.

One major difference is the CSU study encompasses the impacts from fabrication of

materials such as steel. The impact is minimal, confirming that any impact from fabrication

is insignificant compared to other aspects of the projects. Additionally the CSU study did not

consider any impact due to site/earth work, which is very equipment intensive. Even the

most urban construction projects have site and earth work as part of the process. This is a

key difference between the CSU study and the research present here.

The CSU study provides emissions data for just the construction of the building’s structural

frame. The study found that fabrication (use of equipment off site) of materials is essentially

insignificant to the overall project emissions. When converted to tons the CSU study found

that approximately 1.1, 1.9, 110.2, 0.33 and 0.11 of CO, NO

, CO

. SO

, and PM

2006]. This study considers other environmental effects besides air pollutants but it is

unclear what impact these other pollutants have in relation to the air pollutants. The other

pollutants include VOC’s and various heavy metals. In the study equipment contributed

more the 50% of all the air pollutant emissions and as mentioned above the offsite equipment

use (ie. fabrication) was insignificant. When the differences between the CSU study and the

research present here are considered the emissions listed above are comparable to the

findings presented here. The significant contributor is CO

with NO

and CO being much

less then CO

but still 2

and 3

respectively. However the values of NO

and CO are

slightly higher in proportion. The higher value for CO may be explained by a significant

contribution in the CSU study attributable to vibrators, 58% of the total. It is a little unclear

where the increased value of NO

can be accounted for other then the different kinds of

equipment accounted for. [Guggemos and Horvath, 2006]

An interview with the Dr. Guggemos confirmed some of the above observations. Dr.

Guggemos intended the CEDST tool to be all inclusive for emissions estimates. From

fabrication and manufacturing of equipment and materials to the actual on job emissions

from construction, the goal was to include all emissions associated with a project.

Additionally the study only considered the structural frame of the building. The study found

that temporary materials had a large impact on project emissions, in some cases equaling that

3.3

EPA/MRI Studies

Two research projects conducted by the National Risk Management Research Laboratory

(USEPA) in collaboration with the Midwest Research Institute discuss the effect construction

has on particulate emissions. The first of which (discussed below) sought to determine if

current practices for estimating and controlling PM are accurate and sufficient. The second

of which discusses specifically the effect of mud and dirt (fugitive PM) carryout from

construction sites. It is important to note that in the papers referenced and reviewed below

the term emissions refers to Particulate Matter (PM) only.

3.3.1

Particulate Emissions from Construction Activities

Midwest Research Institute completed a study on the discharge of particulate matter (PM)

from construction activities. PM is one of the six widely recognized air pollutants and is

often overlooked. Tests were conducted on various construction sites to observe the PM

levels from both controlled an uncontrolled earthwork as well as loading and unloading. The

PM from mud and dirt carryout was also observed as part of the study. The study collected

field data and compared the data to the calculated amounts according to the standard practice.

Two important goals where to determine if the PM

emission totals calculated were accurate

and additionally whether the PM

:PM

ratio given in published literature is accurate. This

particular study only sought to determine whether or not current practices were accurate and

As described by researchers, current practices are based on EPA emission factors from 1975.

These emission factors assume that construction project emissions are constant over the

entire project with no variations due to materials, vehicles, etc. or from different phases. The

EPA updated this practice in 1993 to allow for a “unit operation” approach, which allows the

work to be broken down into parts and those parts estimated separately. Researchers

performed tests on various different construction operations and during all phases of

construction including a test of mud/dirt carryout which indirectly produces particulate

matter. The tests were performed using EPA accepted test methods for “measurement of

mass and particle size distributions.” Tests were conducted at several locations depending on

the activity being tested. Although these tests are primarily focused on mud, dust, and dirt as

particulate matter it is important to note that the test methods do in fact detect all types of

particulate matter including that from diesel engines. Thus, the researchers in this study do

take into account of the contribution of diesel engine exhaust to particulate matter in their

results. [Muleski, Cowherd, and Kinsey, 2004]

The results of this study varied significantly. In uncontrolled earthmoving activities there

were wide variations from one site to another with one having as much as 430 pounds per

1000 cubic yards (lb/1000 yd

) and another only having 1.7 lb/1000 yd

. These results were

from scraper loading operations. Changes within the individual activities also caused

consistent with each other and showed that an empty scraper’s PM discharge were

approximately half that of a loaded scraper. The EPA equation used to predict PM discharge

from unpaved roads under predicted the results from the transit operations. Particulate matter

discharge is categorized as either PM

or PM

and the ratio of the two is also important to

researchers. In the scraper loading operations one site had consistent results for the ratio

whereas the other site’s results were highly variable. Transit operations had consistent

results across all sites and in general were significantly lower than the loading operations.

[Muleski, Cowherd, and Kinsey, 2004]

Researchers performed a carbon analysis on the collected particulate matter to determine how

significant diesel engines were to the particulate matter levels. It was determined that the

contribution by diesel engines was more significant in the loading operations due in part

because the equipment moves slower and typically has to rev up the engine to efficiently

complete the loading operation. The researchers conducted tests on controlled earthmoving

which is the use of water on construction travel roads to suppress dust. The results show that

this method is effective but the effect decays over time as the soil dries after watering. There

were two aspects to this test the first was the control efficiency of the watering operation and

the second was the decay rate of the dust control. The control efficiency was dependent upon

the surface moisture content and was bilinear in relation. Control efficiency is gained rapidly

dependent upon a range of factors such as ambient temperature, relative humidity, and cloud

cover. [Muleski, Cowherd, and Kinsey, 2004]

This study is related to the work presented in this thesis because it discussed the impact of

construction activities on emissions and particularly in this case particulate matter emissions.

However this study is very different in terms of its methodology and its scope.

3.3.2

Mud/Dirt Carryout as Particulate Emissions

In this EPA paper the researchers sought to measure the impact of mud and dirt carryout

from construction sites as a source of particulate matter emissions. Prior to the study

measurements of PM

at monitoring stations did not match up with the existing inventories

of emissions from dust and dirt. Therefore the researchers’ purpose was to determine the

contribution from and methods of control for PM from mud and dirt carryout. Researchers

found a test site with the required features and correct orientation to make use of ambient

winds. Along the chosen road three sampling stations were set up to enable the appropriate

amount of sampling. Each station had four sampling apparatuses with the middle station

setup to also monitor the carbon content to determine the contribution from car exhaust.

Samples were collected on filter fabric and weighed on scale that was calibrated frequently to

ensure the highest possible accuracy. Additionally other related measurements were taken

data was used to construct a time integrated emissions analysis with further integration with

traffic data for time periods where it is available. Additionally for some of the instruments a

least squares fit was performed on the distributions using a mathematical program. [Kinsey

et al., 2004]

Researchers first determined that PM

emissions were significantly higher downwind from

the source versus upwind with high variation in the height profile. However PM

emissions

were not significantly different downwind versus upwind and much less significant

differences over the height profile. Researchers determined the PM

emissions factor from

the study to be about 6 grams per vehicle with the PM

factor being about 3 percent of

PM

. The PM

factor falls within the EPA’s suggested range but the PM

factor is

significantly lower. PM

rates varied over the course of each day but did trend upwards in

the afternoon along with traffic volume. A comparison between the two sampling methods

used, continuous exposure profiling and time integrated, shows variations between the two,

which this study could not firmly account for and for which future studies would be needed.

[Kinsey et al., 2004]

The particle size of the samples collected was fairly consistent and comparable to related

literature. Two samples collected on different days and at different locations were consistent

with only one previous study and thus proving or disproving the study’s results. The final

matter contributable to vehicles. This was conducted by analyzing the elemental content of

the samples. Sulfur and Iron were significant in the samples due to the presence in both the

source material and vehicle exhaust. Other elements present in the source material showed

significant depletion in the samples taken from the air. Additionally a carbon analysis was

performed to determine the elemental and organic carbon levels in the samples. This found

the majority of the carbon in the samples was organic which is consistent with the volume of

light duty vehicles compared to diesel powered vehicles. [Kinsey et al., 2004]

3.3.3

Study Comparisions

This study is related to the work presented in this thesis because it discussed the impact of

construction activities on emissions and particularly in this case particulate matter emissions.

However that is where the similarities end and the research becomes very different. These

studies both mainly test existing methods for estimating particulate matter emissions from

mud, dust and dirt associated with construction projects. Particulate matter, which is one of

the six does not just come from engine exhaust but rather encompasses any particles that are

less than a certain diameter. For this reason mud and dirt carryout and dust from

construction are important sources of particulate matter in addition to that from engines.

Only particulate matter from engine exhaust are considered in this research and does not seek

to determine the effect of other sources. Although this research and the EPA/MRI studies

These studies also do not discriminate between exhaust related to construction and other

exhausts. The EPA/MRI studies collect data adjacent to construction and not on the site

which would further degrade the accuracy of the particulate matter totals attributable to

exhaust. These two characteristics essentially invalidate the exhaust component of the results

of these studies as construction project impacts. This thesis focuses on using standard tools

to estimate emissions prior to a project completion. Whereas these two studies by the EPA

and MRI conducted experiments to test current practices and develop experimental data for

future changes to the estimating procedures. Both have significant contributions to the area

of construction project environmental impacts but are have different focuses. These studies

scope of work is more environmental health whereas this thesis is focused on pollution and

greenhouse gas contributions.

3.4

Carnegie Mellon Study

Researchers at Carnegie Mellon developed a study relating to the impact of “Construction

Site Energy Use” on the environment. This paper is a comprehensive evaluation of the

construction sectors energy usage. This study evaluated the construction industries fuel

(gasoline and diesel), natural gas and electricity usage and compared each contributor to

other industries and users of those resources. For each contributor researchers presented the

total energy required to produce that resource. For example for electricity it takes a

gained by onsite consumption, 10,360 Btu per kWh produced versus 3,412 Btu gained on site

from a kWh usage [Sharrard, Matthews, and Roth, 2007].

Each category of energy consumption was further broken down by researchers to describe

where that particular resource is used within the construction industry. The breakdown of

diesel and gasoline use was very detailed. Based on the researchers sources they estimated of

the $11 billion spent on fuel $8 billion was for on road vehicles will the remaining

approximately $2.9 billion was for nonroad equipment and vehicles [Sharrard, Matthews, and

Roth, 2007]. The nonroad portion is used to power everything for heavy equipment like

bulldozers and excavators to welding machines and generators and smaller items such as

chainsaws and concrete vibrators. Researchers, to enable further analysis of on versus off

road vehicles, made the assumption that the Department of Commerce’s category of

“off-highway” corresponds to the “nonroad engine and vehicles” category used by the EPA.

The researchers found that a vast amount of particulate matter from on highway vehicles is

attributable to diesel engine exhaust. From there they reasoned that the construction

industry’s contribution therefore is at least significant and should be accounted for.

Researchers believe that this area of study has been vastly overlooked and the majority of

focus is on quantifying off highway fuel use and emissions contributions. Based on their

that comes from the three classifications or types of trucks. These statistics are shown below

in Table 3-1. [Sharrard, Matthews, and Roth, 2007]

Table 3-1 On Highway Truck Usage

Type of On Highway

Truck

Percent from

Construction

Industry

Percent of all

Trucks

Light

6

72

Medium

19

5

Heavy

17

22

Note: Table derived from data presented in Sharrard, Matthews, and Roth, 2007.

The study by Carnegie Mellon also discussed the effect of the EPA’s nonroad diesel rules.

The researchers identified the lack of regulations or rather loose regulations in the past

referring to tier 1 to 3 regulations and the potential for construction sector emissions

reductions due to the new tier 4 regulations that phase in beginning in 2010. These

regulations are not sector specific but rather are generic for all nonroad engines. The new

regulations will drastically reduce the sulfur content of off road diesel fuel and reduce both

NO

and PM emissions from the engines themselves. The study identifies particulate matter

from engines as a target of attention and significant regulation. In 1995 the EPA estimated,

for the first time, more particulate matter emissions from nonroad sources then from onroad

sources. Additionally, nonroad gasoline engines emit only a small fraction of the total

particulate matter emissions from nonroad sources and therefore diesel engines are have a

The use of generators on construction sites to provide electricity to satisfy remote and

immediate power needs was evaluated. A need was identified for case study related to

generator use since there are other means to providing the needed electricity. Due to the fact

that in many cases grid electricity produces fewer emissions than on site generation via a

generator and therefore presents a two fold opportunity to reduce emissions by both using

grid electricity whenever possible and through the increased regulation through EPA’s

engine tier requirements. The study points out that, based on an inventory of Canadian

generators, most generators used are less than 19kW and in Canada most are gasoline.

However the in the US there is a significant market for low powered diesel generators and an

attempt to reduce emissions by increasing regulation would simply cause a substitution of

gas powered generators for diesel due to the increased cost of the cleaner diesel generators.

This would bypass any emissions improvement from increased regulations. [Sharrard,

Matthews, and Roth, 2007]

Another discussion the researchers outlined was the implication and use of hybrid engines for

construction equipment. This idea borrows from the car industry and prevalent “hybrid

vehicles”, whereby an engine is used for two purposes. In this scenario a piece of

construction equipment would be slightly oversized and fitted with a generator to produce

generator when electricity is needed. This scenario’s success depends on the cost to oversize

a piece of construction equipment being less than the cost of a comparable generator to

provide the needed electricity. The researchers also briefly discussed the implications of

hybrid trucks that are now being produced by some of the major vehicle manufacturers.

[Sharrard, Matthews, and Roth, 2007]

This study by Carnegie Mellon provides a wealth of data regarding construction project

energy use both from electricity consumption and fossil fuel combustion. The researchers

found that construction accounts for approximately 3% of the US annual energy consumption

and government estimates only account for about half of what the industry actually uses.

Additionally they point out that the new EPA regulations (tier 4) will provide significant

reductions in both particulate matter and NO

but due to long equipment lifetimes and high

cost of replacement this benefit may not be realized for several years from now. [Sharrard,

Matthews, and Roth, 2007]

The research presented by Carnegie Mellon is a significant step towards quantifying the

construction sector emissions impact. This research has some key similarities with the work

presented here. Even though the researchers presented data and emissions from on and off

road vehicle and electricity use their purpose is to quantify the environmental impact of

construction project which is very similar to the purpose in this thesis. However the

whereas in the Carnegie Mellon study estimate energy use using fuel consumption, for

engines, and usage rates for electricity. Both also agree that the need for quantifying the

construction industry emissions and environmental impact is real becoming ever more

important.

Another source of agreement is the importance of nonroad vehicles in reducing the

construction sector’s impact. Even though onroad vehicles are identified by the researchers

as significant there is much more room for improvements in the nonroad vehicle and engine

component. However the researchers do not offer a methodology or tool to calculate

emissions or environmental impact but rather just seek to quantify the sector wide impact.

This thesis seeks to present a methodology or tool to calculate the emissions due to a single

project to help identify further any areas that can be reduced.

3.5

University of Illinois Urbana-Champaign Research

Researchers at the University of Illinois at Urbana Champaign (UIUC) have developed

studies on the greenhouse gas emissions due to construction. They first developed a

procedure for visualizing the emissions of a construction activity using geographic

information systems (GIS). GIS was chosen because of its ability to both display data and

perform spatial analysis on such data. With the addition of a CAD interface the visualization

GIS data is three dimensional and in this emissions analysis the construction site represented

the X-Y plane. (X, Y). Emission levels were represented using the third dimension. This

created a tin file with X, Y and Z coordinates that could then be plotted into a surface. This

showed the concentration of emissions in a three dimensional view. The result is a better

understanding of emissions and an improved ability to manage them. This information

provides a link between spatial and non spatial data related to construction and demonstrated

its use with a case study. [Ahn et al., 2009]

Managing of emissions on construction projects was subsequently evaluated due to the

importance of construction environmental impacts. UIUC researchers identified the

difficulty involved in controlling construction emissions since current regulations only

govern new equipment emission rates. Researchers found that “ISO 14001… suggests a

framework for managing the environmental impacts of activities… of an organization”

[Peña-Mora et al., 2009]. However they identify the difficulty associated with achieving the

goals establish by the ISO. Then researchers developed a method that would allow for better

managing of the emissions from a project. This method involved establishing the planned

activity/process and assigning emissions to that process to get the planned or estimated

activity emissions. Then using portable emission measuring devices the actual emissions are

monitored and compared to the plan and corrective actions are taken to mitigate overages that

occur. GPS technology also provide location information to allow for visualization based on

In the UCIC studies researchers found that GIS has a potential to improve construction but

the full potential has not been realized on construction projects as of yet. The integration of

spatial and non spatial data provides a more reliable picture of the construction process. This

integration and visualization can provide additional support in decision making on projects.

Successful integration of these technologies prove that construction can become more

technologically advanced and realize improvements from such advances. This type of

information and process can provide the ability to compare various aspects of a project and

help planners understand the overall impact. In addition, with this and other technologies, it

is possible to evaluate emissions prior to construction and monitor emissions during

construction and thereby provide the opportunity to mitigate the emissions effects of a

project. With this added methodology, evaluating the sustainability of construction

operations can become integrated into the construction operations. [Peña-Mora et al., 2009]

This research by UIUC is related to the work presented here. The two both seek to determine

the emissions of construction projects. While the research by UIUC provides a detailed

analysis of one activity this thesis strives to determine all the activities impact and thereby

the total projects impact. Both research projects use estimation tools to provide emissions

estimates of construction activity’s GHG emissions. This thesis examines six common

and estimated emissions for their research and focused on GHG emissions. The visualization

aspect of UI’s research was not duplicated in this research due to the lack of usability. The

ultimate goal of both projects is the development of data and methods for addressing the

environmental impact of construction and thus enabling the better management of that

impact.

3.6

North Carolina State University Research

The research conducted at North Carolina State University (NCSU) was the building block

for the research outlined in this paper. The researchers sought to develop datasets of diesel

engine emissions from nonroad construction equipment [Frey et al., 2007]. Fleets of various

construction equipment including backhoes, wheel loaders, motor graders as well as other

equipment were instrumented to record emissions during a range of different activities [Frey

et al., 2008b & Lewis, Frey and Rasdorf, 2010]. The study conducted by NCSU researchers

sought to build a dataset of actual emissions data where no previous data existed. Although

the EPA NONROAD model gives emissions based on engine size and type the model is

derived from engine dynamometer data adjusted with correction factors rather than on actual

measurement data. The NONROAD model cannot account for fluctuation in revolutions per

minute (RPM), engine tier or fuel consumption variations and provides engine horsepower

All these factors mean that the typical estimate from the NONROAD model should be higher

than the actual in most cases. Researchers at NCSU sought to develop comprehensive

datasets of experimental or actual emission rates of a variety of equipment to provide a

comparison to existing emissions models. The objective for the research was to obtain

detailed data for a small group of equipment. Researchers choose eight different equipment

types and various activity modes depending on the equipment [Lewis, Frey and Rasdorf,

2009a]. See Table 3-2 for the activity modes utilized by NCSU researchers for tracking of

the emissions data. For each equipment type multiple pieces of equipment were

instrumented and tested. For the more popular and prevalent equipment up to eight were

tested but for each type a minimum of three were tested [Lewis, Frey and Rasdorf, 2009b].

Once researchers had the raw data it was compiled and separated by engine mode for each

Table 3-2 Activity Modes for Construction Equipment

Equipment Activity

Mode

Backhoe-Loader

Idling

Moving

Scoop/Dump Front Bucket

Scoop/Dump Rear Bucket

Bulldozer

Idling

Forward

Reverse

Blade

Excavator

Idling

Moving

Scoop/Dump

Cycle

Motor Grader

Idling

Moving

Blade

Off-Road Truck

Idling

Moving

Hauling

Dumping

Track Loader

Moving

Idling

Scoop/Dump

Wheel Loader

Idling

Moving

Scoop/Dump

Note: Table comes from Lewis, Frey and Rasdorf (2009b), table 3.2

Using the collected data researchers analyzed the fuel use and engine mode correlations

using regression models and other forms of statistical analysis. Representative duty cycles

for each type of equipment were then generated to facilitate the analysis of time and fuel use

in each mode of the given duty cycle. Then both the fuel use and emission rates for the

mass per fuel used weighted-average emission rate to a mass per time weighted-average

emission rate” [Lewis et al., 2009]. Researchers published several papers on this research

detailing all aspects of the process including a detailed paper on the duty cycles of the

various equipment as well as a comparison of biodiesel with regular diesel in nonroad

engines [Frey et al., 2008a]. They also outlined the field procedures for measuring emissions

from construction equipment to enable future research to validate their results.

Another aspect of this research was what to do to encourage and aid the reduction in

emissions form construction equipment. This is a multifaceted problem with solutions that

vary from changing current emissions laws to modifying the means and methods of

construction. There are ways to reduce emissions by simply changing the way the work is

completed, which is based on duty cycle analysis. The reduction of emissions can be

affected by changing operator’s mentalities about certain “myths” or false truths such as the

idea that it takes more fuel to start a diesel engine then to just let it idle. Based on research

reducing idling time will amount to a direct reduction in emissions. The behavior aspects to

emissions reductions in the above paragraph need to also go hand in hand with incentive

based methods for reductions as outlined by Lewis, Frey and Rasdorf [2009b]. Incentives

can vary from reduced fuel usage by newer equipment to government backed programs to

encourage the purchase of newer, higher tier, equipment. Along with incentives there are

The study by NCSU produced data related to construction equipment emissions. The data

from the field measurements coincided well with the EPA NONROAD Model estimates. For

some equipment and emission type combinations the field data was lower and for other

combinations it was higher. However the variations were not significant and the differences

were minimal. The only pollutant that shows significant variation from the NONROAD

estimate was PM which was attributed by researchers to the method for measurement which

is known to be less accurate then other available methods.

4.0

MODELS USED IN RESEARCH

Two models were used to develop the case presented here; the EPA’s NONROAD Model

and RS Means CostWorks estimating tool. Individually these tools are unrelated. This study

attempts to develop a methodology to connect the two.

4.1

NONROAD Model

The EPA has developed one model to estimate emissions from all types of nonroad

equipment. This model is referred to as the EPA NONROAD Model and is widely used as a

basis for generating emissions estimates. The model has an abundant source of data that can

be queried in different ways. The user can choose whether to use nationwide data or

statewide data. Additionally the model allows the user to select the different types of engines