Carbon Footprint of Lucas County Facilities and Operations
Final Report
Energy and Greenhouse Gas Inventory of
Lucas County Facilities and Operations
Prepared by
Katherine Chulski
Gregory Denman
Jeff Grabarkiewicz
Praneeth Nimmatoori
Hannah West
Prepared for
Lucas County Commissioners
and
CIVE 6900/8900 Sustainability Engineering and Science
University of Toledo
Department of Civil and Environmental Engineering
Fall 2010
December 13, 2010
Final Report
Abstract
This report quantifies the energy use and greenhouse gas emissions of Lucas County facilities and operations. Scope 1 emissions and Scope 2 emissions were calculated for the years 2005 to 2009. Scope 1 emissions included wastewater treatment, vehicle fleet, and natural gas combustion. Scope 2 emissions included purchased electricity by facilities, pump stations, and traffic signals. It was found that the total greenhouse gas emissions which include both scope 1emissions and scope 2 emissions, showed an increasing trend from 2005 to 2009 and were projected to increase in future years. The total greenhouse gas emissions for the year 2009 were 30,556 MTCO2e. Results showed that the primary contributor to these emissions was energy usage within facilities which accounted for 73% followed by energy usage within wastewater treatment plant – 21%, vehicle fuel – 6% and traffic lights – less than 1%. The methodology used to calculate these emissions was explained. The measures to reduce these emissions were also discussed.
Acknowledgements
This project would not have been possible without the collaboration and assistance of Defne Apul, Jim Shaw, Veronica Jackson, Mike Cravens, Lynn DiPierro, Earl Reid, Chris Pizza, Keith Earley, Ron Myers, Kara Moore, Kim Kettman, Bridgette Kabat, Tina Wozniak, Meg Adams, and Ray Evans.
Table of Contents
1.0 Introduction 8
2.0 Project Objectives 9
3.0 Methods 10
3.1 Project Site Description 10
3.2 Raw Data 11
3.2.1 Scope 1 Emissions 12
3.2.2 Scope 2 Emissions 21
3.2.3 Scope 3 Emissions 25
3.2.4 Biogenic Emissions 26
4.0 Results and Discussion 26
4.1 Scope 1 Emissions 27
4.1.1 Wastewater Treatment Facility 28
4.1.2 Vehicle Fleet 30
4.1.3 Natural Gas 31
4.2 Scope 2 Emissions 32
4.2.1 Facilities 33
4.2.2 Traffic Signals 34
4.3 Projections 35
4.4 Putting Emissions into Perspective 36
5.0 Conclusions and Recommendations 38
References 40
List of Figures
Figure 1: Map of Lucas County 9
Figure 2: Lucas County Maumee River Wastewater Treatment Facility 12
Figure 3: Annual emissions by sector type 25
Figure 4: Scope 1 Emissions for 2009 26
Figure 5: Annual CO2e emissions for 2009 at the MRWWTP 27
Figure 6: Scope 2 Emissions for 2009 31
Figure 7: Energy usage from the US Department of Energy “Buildings Energy Data Book 32
Figure 8: Annual emissions broken out into Scope 1 and 2 contributions 33
Figure 9: Projections for Scope 2 emissions over the years 2010 to 2014 34
Figure 10: Greenhouse Gas Equivalence Calculator (Source: EPA) 35
Figure A.1: eGRID Sub Regions (2006 and 2007) 41
Figure D.1: Vehicle Fleet Data 45
Figure D.2: Natural Gas Usage Data – Columbia Gas 46
Figure D.3: Natural Gas Usage Data –CCAO (Bulk Gas) 46
Figure D.4: Facility Energy Usage Data – Toledo Edison 47
Figure D.5: Facility Energy Usage Data – Department of Public Utilities (Water) 47
Figure D.6: Traffic Signal Data 48
Figure D.7: Pump Station Data 49
Figure D.8: General Fund County Vehicles with City and Highway MPG 50
Figure F.1: Scope 1 Emissions from 2005 to 2009 52
Figure F.2: Scope 2 Emissions from 2005 to 2009 52
List of Tables
Table 1: Raw data received from Lucas County 10
Table 2: Organizations utilizing fleet vehicles, fueled by Vehicle Maintenance 16
Table 3: List of Buildings 21
Table 4: Facilities Activity Data 21
Table 5: Pump Station Activity Data 22
Table 6: Traffic Signal Activity Data 22
Table 7: Maumee River Wastewater Treatment Plant Activity Data 23
Table 8: Emission Factors from Toledo Edison vs. eGrid 23
Table A.1: Emission Factors for CO2 40
Table A.2: Emission Factors for CH4 and N2O 41
Table A.3:eGRID 2007 Electricity Emission Factors by Sub Region 42
Table C.1: Project Schedule. 44
List of Appendix
Appendix A: Emission Factors 41
Appendix B: Team Member Responsibilities 44
Appendix C: Project Schedule 45
Appendix D: Raw Data 46
Appendix E: Facility Data Limitations 52
Appendix F: Annual Emissions Graphs 53
1.0 Introduction
A carbon footprint represents the total amount of greenhouse gases produced by an individual, entity, product, or event (measured in units of carbon dioxide equivalence). Therefore, it measures the impact we make individually as well collectively through our lifestyle choices. Environmental issues such as global warming are also linked to CO2 emissions. The carbon footprint of an individual, organization, or nation can be measured by undertaking a greenhouse gas (GHG) emissions assessment. Through this assessment, an organization can understand the impact of its facilities and operations on global warming. Once the emissions are known, a reduction strategy may be formulated. This strategy often achieves reductions through technological developments, better process and product management, and consumption strategies.
2.0 Project Objectives
The goal of this study was to determine was to:
· Determine the greenhouse gas emissions of the facilities and operations of Lucas County, Ohio.
· Investigate methods to reduce the emissions of Lucas County.
· Project annual emissions for future year(s) taking reduction methods into account.
To assist in the analysis, the “Local Government Operations Protocol for the quantification and reporting of greenhouse gas emissions inventories” will be used. This method was developed by the California Air Resources Board, California Climate Action Registry, ICLEI – Local Governments for Sustainability, and The Climate Registry.
Facilities under examination within this project include buildings, ports, airports, solid waste facilities, water treatment and delivery facilities, wastewater treatment facilities, and power generation facilities. Emissions associated with these facilities, in addition to the operational products of Lucas County that fall under Scope 1 emissions, Scope 2 emissions, Scope 3 emissions, and biogenic emissions will be examined. The annual emissions will then be calculated for the years 2005 to 2009. This method will allow yearly comparisons. The scope of this project does not include emissions related to forestry and land management. Emissions data for similar county facilities across the United States will be obtained and indicators will be examined.
3.0 Methods
Methods used to quantify emissions required activity data and emissions factors. Activity data obtained from Lucas County included fuel consumption by fuel type, metered monthly energy consumption by unit, and annual vehicle mileage by vehicle type. Activity data along with emissions factors for each activity type were multiplied to determine the relative emissions. Emissions factors used in this report were adapted from the Local Governments Operations Protocol, 2010 and were determined by means of direct measurement, laboratory analysis or calculations based on representative heat or carbon content.
3.1 Project Site Description
Lucas County is located in Northwest Ohio, on the shores of Western Lake Erie just south of State of Michigan. It is part of the Toledo Metropolitan Area. The outline of Lucas County is shown in Figure 1. This figure is borrowed from the Wikipedia page for Lucas County (http://en.wikipedia.org/wiki/File:Map_of_Ohio_highlighting_Lucas_County.svg) and paired with an image from Google Earth. According to the Ohio Department of Development, Lucas County spans 596 square miles, with 340 square miles of land area. In 2009, the population of the county was estimated to be 463,493 (ODOD 2010).
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Carbon Footprint of Lucas County Facilities and Operations
Final Report
Figure 1: Map of Lucas County
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Carbon Footprint of Lucas County Facilities and Operations
Final Report
3.2 Raw Data
The local government sectors considered for this project are listed in Table 1. The status of data acquisition and the individual who provided the data are also included. The county does not own or operate any water treatment facilities, ports, airports, transit fleet, power generation facilities, or solid waste facilities. While the county does not manage or own a landfill, they do consistently spend approximately $11,000/month on fuel for trucks to collect recyclables from area schools and facilities.
Table 1: Raw data received from Lucas County
Sector / Data Acquired / Provided byBuildings / Yes / Earl Reid
Traffic Signals / Yes / Keith Earley
Water Delivery Facilities / N/A / N/A
Port facilities / N/A / N/A
Airport facilities / N/A / N/A
Vehicle Fleet / Yes / Bridgette Kabat, Lynn DiPierro, Keith Early,
Kim Kettman, Veronica Jackson, and Jim Shaw
Transit Fleet / N/A / N/A
Power Generation Facilities / N/A / N/A
Solid Waste Facilities / N/A / N/A
Wastewater Facilities / Yes / Mike Cravens and Jim Shaw
3.2.1 Scope 1 Emissions
Scope 1 emissions involve those emissions which are directly produced, including emissions from stationary combustion, mobile combustion, process emissions, and fugitive emissions. For Lucas County, this includes emissions produced during treatment processes at the wastewater treatment plant, emissions produced from the fleet vehicles, and natural gas usage within the County’s facilities.
3.2.1.1 Wastewater Treatment Facility
Wastewater treatment facilities include stationary, fugitive and process emissions relative to Scope 1 emissions. They also include scope 2 Emissions related to any facilities used for the conveyance, collection or treatment of the wastewater/sewage. This typically includes treatment facilities, booster stations, in-line pumps and lift stations.
Plant Overview
Lucas County owns and operates the Lucas County Maumee River wastewater treatment plant (MRWWTP) which is located on the Maumee River (Figure 2). The treatment facility was constructed in 1971. Several expansions and improvements have occurred since the facilities inception. The plant can now treat 22.5 MGD and serves a population of 80,500 people. Wastewater enters the plant by means of a 90-inch sewer. Liquid ferrous chloride is injected into the raw influent to remove phosphorus and control odor. The influent is then diverted to either the East or West treatment plant. Both plants use filter screens to remove material greater than ¼” diameter. Both plants also filter the influent through grit removal. The east plant uses an aerated grit chamber while the west plant has a vortex grit removal unit. Screenings and grit removed from the influent are stored on sand filter drying beds and eventually transported to a local landfill.
Influent flows are measured prior to preliminary treatment. The influent wastewater is pumped to primary settling tanks. Sludge is then pumped to the anaerobic digesters using cavity pumps. Primary effluents then flow by gravity to the aeration basins. Ferrous chloride is added once again in the aeration basin to remove phosphorus. Secondary treatment then begins via the activated sludge process. The water is then sent to the final clarifiers where solids separation occurs. The clarified effluent flow is measured in each plant via a Parshall flume before ultraviolet disinfection. East and west plant effluents are combined and then discharged to the Maumee River. The methane gas produced in the digesters is used to run generators that produce electric power and hot water for the digester/cogeneration complex. Digested sludge from the secondary digester is dewatered and then placed on a storage pad to dry. Hauling contractors remove the class B biosolids and land apply them.
Figure 2: Lucas County Maumee River Wastewater Treatment Facility
CH4 Emissions
CH4 emissions are associated with several factors of wastewater treatment. They can arise from septic systems, aerobic systems that are poorly managed, anaerobic treatment, facultative treatment lagoons and from captured biogas from anaerobic digesters that is not completely combusted. The MRWWTP operates anaerobic digesters to treat excess biosolids produced by the wastewater treatment process. The anaerobic digestion creates CH4 which is then combusted. Stationary CH4 production from the incomplete combustion of digester gas was calculated using Equation 1.
Annual CH4emissions MTCO2e= P×Digester Gas ×F CH4×ρCH4×1-DE× 0.0283 m3ft3×365.25 daysyear×10-6 MTg×GWP (1)
Where: P =population served by MRWWTP (80,500 people)
Digester Gas =volume of digester gas produced 1ft3personday
F CH4 =Fraction of CH4 in biogas (0.65)
ρCH4 = Density of methane 662 gm3
DE =CH4 Destruction efficiency (0.99)
GWP =Global warming potential of CH4(21)
N2O Emissions
N2O is generated at wastewater treatment facilities during the processes of nitrification and de-nitrification. Nitrogen is usually present in the form of urea, ammonia and proteins. These compounds are converted to nitrate (NO3) by nitrification. De-nitrification then converts the NO3 to dinitrogen gas (N2). Process emissions for N2O can be calculated using two different equations which relate to whether or not the WWTP used nitrification/de-nitrification. At the MRWWTP this process is not employed. Equation 2 was used to determine the N2O emissions at the MRWWTP. N2O emissions are also associated with effluent discharge to receiving aquatic environments. Equation 3 was used to calculate the emissions from this source.
N2O emissions= Ptotal×EFwonitdenit×10-6 MTg×GWP (2)
Where: Ptotal =Polpulation served by MRWWTP (80,500 people)
EF wo nitdenit =Emission factor for WWTP without nitdenit3.2 gN2Opersonyear
GWP =Global warming potential of N2O 310
N2O emissions=Ptotal×Total N Load-N uptake ×BOD5 load×EF effluent×4428 ×1-F plant nitdenit×365.25daysyear×10-3MTkg×GWP (3)
Where: Ptotal =polpulation served by MRWWTP Number of people
Total N Load = Total nitrogen load 0.026 Kg Npersonday
N uptake =N uptake for cell growth in aerobic system 0.05 Kg KKg BOD5
BOD5 load =Amount of BOD5 produced 0.09 Kg BOD5personday
EF effluent =emisions factor 0.005Kg N2O-NKg sewage-N produced
44 28 =Molecular weight ration of N2O to N
F plant nitdenit=Fraction of nitrogen removed 0 for plantwonitdenit
GWP =Global warming potential of N2O310
3.2.1.2 Vehicle fleet
Three departments are primarily responsible for the maintenance and fueling of Lucas county fleet vehicles: Vehicle Maintenance (general fund), County Engineer’s Office, and the Sanitary Engineer’s Office. Vehicle make and models were provided by the respective County offices and the Board of Lucas County Commissioners. The County Engineers provided a record of gasoline and diesel purchased for road maintenance vehicles in 2009. The Sanitary Engineer’s Office provided records of gasoline and diesel purchased for 2008 and 2009. Vehicle Maintenance provided a record of gasoline purchased during a five year period. Many different county departments rely on Vehicle Maintenance for their fueling needs. Those departments are shown in Table 2.