Comparative Life Cycle Assessment and Cost Analysis of Bath Wastewater Treatment

Plant Upgrades

Ben Morelli 1, Sarah Cashman 1, Xin (Cissy) Ma 2,*, Jay Garland 3, Jason Turgeon 4, Lauren Fillmore 5, Diana Bless 2 Michael Nye 3

Northeast Residuals & Biosolids Conference 2017 October 25-27, 2017 Burlington, VT

1 Eastern Research Group 2 United States Environmental Protection Agency, National Risk Management

Research Laboratory 3 United States Environmental Protection Agency, National Exposure

Research Laboratory 4 United States Environmental Protection Agency, Region 1

5Water Environment & Reuse Foundation

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A system is more than the sum of its parts. - Aristotle (384-322 BC)

New concepts • Fit for purpose

–  Water reuse

• Source separation and resource recovery –  Nutrient recovery –  Energy recovery

• Decentralization

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3

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• Population: 5,600

• Flow Capacity: 1 MGD

• Legacy WWTP: CAS

• Upgraded WWTP: MLE

biological treatment

MGD – Million gallons per day WWTP – Wastewater Treatment Plant CAS – Conventional Activated Sludge MLE – Modified Ludzack-Ettinger

Bath NY Community & Wastewater Treatment

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Bath NY Community & Wastewater Treatment

– Bath wwtp – Food manufacturers – Beverage manufacturers

• Population: 5,600

• Flow Capacity: 1 MGD

• Legacy WWTP: CAS

• Upgraded WWTP: MLE

biological treatment

MGD – Million gallons per day WWTP – Wastewater Treatment Plant CAS – Conventional Activated Sludge MLE – Modified Ludzack-Ettinger

Legacy System Diagram

Primary Treatment

CAS

Secondary Treatment

Effluent Release

Solids

Thickening

Landfill

Aerobic Digestion

Dewatering

Plant Infrastructure Disposal, Sewer Maintenance, Electrical and Mechanical System Material

T T Septage & HSOW

Chemical Addition

Process GHG Emission Foreground Energy T Transport Background

Upgraded System Diagram

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Chemically Enhanced Primary Treatment

Chemical Addition

Aerobic

Process GHG Emission

Advanced Secondary Treatment Effluent

Release

Solids

Gravity Belt Thickening

Composting & Land

Application Dewatering

Foreground Energy

Plant Infrastructure Disposal, Sewer Maintenance, Electrical and Mechanical System Material

T T Septage & HSOW

T Transport

Anoxic

Anaerobic Digestion

T

Background

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• Comparative analysis of legacy and upgraded WWTPs • Energy recovery potential and avoided product benefits of Anaerobic Digestion (AD) and land application of compost –  Effect of adding High Strength Organic Waste (HSOW)

• Calculate life cycle costs of upgraded system

Bath NY Community & Wastewater

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* SPDES – State Pollutant Discharge Elimination System

Influent & Effluent Characteristics

Characteristic Influent

Effluent Legacy Upgraded

(mg/L) Suspended Solids 437 7.9 5 Biological Oxygen Demand 323 8.5 2.3 Total Kjeldahl Nitrogen 56 16 4.4

Ammonia 32 6.7 3.6 Total Phosphorus 8 0.7 0.6 Nitrite <1 2.8 0.8

Nitrate <1 13 14

Organic Nitrogen 29 9 0.8

Total Nitrogen 61 31 20

Select LCI Calculations • Electricity: calculated using a record of equipment use, horsepower, and run time • Chemicals: via provided dosage rates • Process GHGs

–  N2O: based on TKN influent to secondary (Chandran 2012)

–  Methane: based on BOD influent to secondary (IPCC 2006) •  Assigns methane correction factor for specific treatment units

(Legacy – Czepiel 1993, Upgraded – Daelman et al. 2013)

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Select LCI Calculations continued… • Biogas Production (Upgraded Plant)

–  Based on Volatile Solids (VS) destruction assumption (ft3/day)

• Landfill Emissions (Legacy Plant) –  Regional and national average gas capture

performance –  Degradation via a first-order decay model

• Composting Emissions (Upgraded Plant) –  Methane (0.11%, 0.82%, 2.5% of C) –  Nitrous Oxide (0.34%, 2.68%, 4.65% of N) –  Ammonia (1.2%, 6.7%, 12.74% of N) –  Carbon Monoxide (0.04% of C) 11

Life Cycle Costing

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Total Costs = Ʃ (Annual Costs) + Ʃ (Amortized Capital Costs) Total Capital Costs = Purchased Equipment Costs + Direct Costs + Indirect Costs Total Annual Costs = Operation Costs + Replacement Labor Costs + Materials Costs + Chemical Costs + Energy Costs Net Present Value=Σ(Costx/(1+i)x)

Anaerobic Digestion – Feedstock Scenarios

• 3 feedstock scenarios analyzed to determine variation in environmental and cost performance (300,000 gal tanks)

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Waste Type Base

(gal/day) Medium (gal/day) High (gal/day)

Primary Sludge 17,654 17,654 17,654

Waste Activated Sludge 75,557 75,557 75,557

Septic Waste 14,000 14,000 14,000 Slaughterhouse Waste - 1,000 4,000 Cheese Waste - 2,000 3,000

Winery Waste - 1,000 1,000

Portable Toilet Waste 2,000 2,000 2,000

Loading (lb VS/1000 ft3/day) 130 158 205

Anaerobic Digestion Operational Scenarios

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Parameter Name

Low Yield Base Yield High Yield

UnitsValue Value Value

Percent Volatile Solids Reduction 40 50 60 %

Biogas YieldBase 12.0 15.0 24.5 ft3/lb VS destroyed

Medium 13.8 18.5 25.1 ft3/lb VS destroyed

High 15.7 22.2 27.3 ft3/lb VS destroyed

Methane Content of Biogas 55 60 65 % w/w

Biogas Heat Content (MJ/ft3) 0.59 0.64 0.68 MJ/ft3

Electrical Efficiency 33 36 40 %

Thermal Efficiency 46 51 56 %

Reactor Heat Loss Northern US Northern US Southern US n.a.

Anaerobic Digestion – Performance Scenarios

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Compost Emission Scenarios

Emission Scenario

Emission Species Element

Loss of Incoming Element to GHGsUnits

Low CH4 C 0.11% incoming C lost as CH4

Low N2O N 0.34% incoming N lost as N2O

Base CH4 C 0.48% incoming C lost as CH4

Base N2O N 2.68% incoming N lost as N2O

High CH4 C 1.70% incoming C lost as CH4

High N2O N 4.65% incoming N lost as N2O

Eutrophication Scenarios Percent of Legacy System Impact

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0%10%20%30%40%50%60%70%80%90%100%

Percen

tofLegacySystem

Impact

Scenario Name: Feedstock – AD, i.e., base feedstock – base AD performance

Chart Reading Example

Eutrophication Potential Process Contribution

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2.4E-2

1.5E-2 1.4E-2

1.9E-2

0

5.0E-3

1.0E-2

1.5E-2

2.0E-2

2.5E-2

3.0E-2

Legacy (Base)

Upgraded (Base)

Upgraded (Optimized)

Upgraded (Worst Case)

kg N

-eq/

m3

was

tew

ater

trea

ted

Effluent Release

Sludge Disposal

Sludge Handling and Treatment Facilities

Biological Treatment

Preliminary/Primary

Global Climate Change Potential Scenarios

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-100%-50%0%

50%100%150%200%250%300%350%400%

RelaAvePe

rcen

tofLegacySystem

LowEmissions BaseEmissions HighEmissions

Scenario Name: Feedstock - AD

Bar height below this line indicates reduced impact relative to Legacy System

Global Climate Change Potential Process Contribution

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0.78 0.97

-0.73

3.10

-2

-1

0

1

2

3

4

5

Legacy (Base)

Upgraded (Base)

Upgraded (Optimized)

Upgraded (Worst Case)

kg C

O2-

eq/m

3 w

aste

wat

er

Effluent Release

Sludge Disposal

Sludge Handling and Treatment Facilities

Biological Treatment

Preliminary/Primary

Total

Cumulative Energy Demand Scenarios Percent of Legacy System Impact

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-150%

-100%

-50%

0%

50%

100%

150%

200%

RelaAvePe

rcen

tofLegacySystem

LowEmissions BaseEmissions HighEmissions

Scenario Name: Feedstock - AD

Bar height below this line indicates reduced impact relative to Legacy System

Cost Analysis Upgraded System

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$29

$34

$46

$28

$33

$46

$26

$32

$44

$25

$31

$44

$23

$30

$42

$20

$28

$40

-$10

$0

$10

$20

$30

$40

$50

LowCost

BaseCost

HighCost

LowCost

BaseCost

HighCost

LowCost

BaseCost

HighCost

LowCost

BaseCost

HighCost

LowCost

BaseCost

HighCost

LowCost

BaseCost

HighCost

MillionDo

llars

ConstrucAon($) OperaAon($/yr) Maintenance($/yr) Material($/yr) Chemical($/yr) Energy($/yr) TotalNPV

AD and Compost Payback

• Difficult to achieve with low acceptance of high strength organic waste.

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Scenario (Feedstock Scenario-Anaerobic Digester Scenario)

Low Cost Scenario Base Cost Scenario High Cost Scenario

Anaerobic Digester

Composting Facility

Anaerobic Digester

Composting Facility

Anaerobic Digester

Composting Facility

Base Feed-Low AD None None None None None None Base Feed-Base AD None None None None None None Base Feed-High AD 72 None None None None None

Medium Feed-Low AD None 39 None None None None Medium Feed-Base AD 271 82 None None None None

Medium Feed-High AD 32 440 177 None None None High Feed-Low AD 219 11 None None None None High Feed-Base AD 40 13 251 None None None High Feed-High AD 16 18 41 None 45 None

Summary of Relative Scenario Impacts

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EOL Low

B

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ase

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Feed-AD Lega

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Lega

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Low

GCCP -41% - 44% -57% 25% 141% -105% -28% 79% -32% 57% 183% -112% 2% 163% -139% -32% 119% -63% 61% 236% -158% 0% 222% -194% -49% 155% -117% 57% 299%

EP 0% - 0% -38% -37% -36% -42% -41% -40% -35% -34% -33% -36% -35% -33% -41% -40% -39% -32% -31% -29% -34% -32% -30% -42% -40% -38% -28% -26% -24%

PMFP 2% - -2% 7% 11% 15% -100% -96% -92% 38% 42% 46% -34% -29% -23% -161% -156% -151% 22% 28% 34% -113% -106% -98% -287% -280% -273% -9% 0% 8%

SFP 2% - -2% 7% 7% 7% -101% -101% -101% 37% 37% 38% -35% -35% -35% -163% -163% -163% 21% 21% 22% -116% -116% -116% -290% -290% -290% -11% -11% -11%

AP 2% - -2% 16% 31% 46% -90% -77% -62% 47% 63% 79% -20% -1% 21% -145% -127% -107% 37% 58% 82% -93% -65% -35% -264% -239% -212% 13% 43% 76%

WU 0% - 0% -104% -103% -103% -108% -108% -107% -111% -111% -110% -139% -138% -137% -142% -142% -141% -148% -147% -147% -187% -187% -186% -189% -189% -188% -201% -200% -199%

FDP 1% - -1% 9% 9% 9% -98% -98% -98% 68% 68% 69% -63% -63% -62% -133% -132% -132% 48% 49% 49% -112% -112% -111% -207% -207% -206% -4% -3% -2%

CED 2% - -1% 5% 5% 6% -98% -97% -97% 57% 57% 58% -60% -59% -59% -136% -135% -135% 38% 38% 39% -113% -112% -112% -216% -215% -215% -10% -9% -8%

Legacy Baseline -38% Impact Reduction 25% Increase in Impact

+/- 10% of Legacy -103%

Net Negative Impact 141% Impact More Than

Doubled

Conclusions •  Clear Environmental Benefit of HSOW Acceptance

– Maximize use of AD capacity

– Low AD performance (avoidable), can lead to increases in environmental impact

•  Benefit to Climate Change Potential depends strongly on composting system selection and management

•  Simple payback of AD is challenging to achieve at small-scale, but the trend is towards decreasing cost

•  Many impact categories positively influenced by avoided electricity and natural gas consumption

•  Appropriate use of AD has the potential to reduce environmental impacts of achieving increased nutrient removal

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Acknowledgements This research was part of the U.S. Environmental Protection Agency (U.S. EPA) Office of Research and Development’s Safe and Sustainable Water Resources (SSWR) Program. The research was supported by U.S. EPA contracts EP-C-12-021 and EP-C-16-0015. Kim Miller and Guy Hallgren provided primary data on the Bath, NY wastewater treatment plant operations and infrastructure for both the legacy and upgraded systems investigated. Engineering design of treatment plant upgrades was performed by personnel from Conestoga-Rovers & Associates, now a division of GHD Inc. Lauren Fillmore and Lori Stone of Water Environment & Reuse Foundation (WE&RF) as well as Pradeep Jangbari of New York State Department of Environmental Conservation provided technical review comments. Jason Turgeon and Michael Nye of U.S. EPA helped develop the initial project scope. Janet Mosely and Jessica Gray of Eastern Research Group provided technical input and review of the life cycle inventory and cost analysis.

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The views expressed in this presentation are those of the author[s] and do not necessarily represent the views or policies of the U.S. Environmental Protection Agency. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. This presentation has been reviewed in accordance with U.S. Environmental Protection Agency policy and approved for publication.

Disclaimer

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Contact Information

Xin (Cissy) Ma Ph.D, P.E. Ma.cissy@epa.gov

Ben Morelli ben.morelli@erg.com

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Sarah Cashman sarah.cashman@erg.com

Chandran, K. 2012. Greenhouse Nitrogen Emissions from Wastewater Treatment Operation: Phase I, Final Report. Water Environment Research Foundation. U4R07.

Czepiel, P.M., P.M. Crill, and R.C. Harriss. 1993. Methane Emissions from Municipal Wastewater Treatment Processes. Environmental Science and Technology. 27: 2472-2477.

Czepiel, P., P. Crill, and R. Harriss. 1995. Nitrous Oxide Emissions from Municipal Wastewater Treatment. Environmental Science and Technology. 29: 2352-2356.

Daelman, M.R.J., E.M. Voorthuizen, L.G.J.M. van Dongen, E.I.P. Volcke, and M.C.M van Loosdrecht. 2013. Methane and Nitrous Oxide Emissions from Municipal Wastewater Treatment–Results from a Long-Term Study. Water Science and Technology. 67(10): 2350-2355.

IPCC. 2006. 2006 IPCC Guidelines for National Greenhouse Gas Inventories, Prepared by the National Greenhouse Gas Inventories Programme, Eggleston H.S., Buendia L., Miwa K., Ngara T. and Tanabe K. (eds). Published: IGES, Japan

ISO-NE (Independent System Operators New England). 2016. 2014 ISO New England Electric Generator Air Emissions Report. http://www.iso-ne.com/static-assets/documents/2016/01/2014_emissions_report.pdf Accessed 30 August, 2016.

U.S. EPA (U.S. Environmental Protection Agency). 2016. Power Profiler Tool. https://www.epa.gov/energy/power-profiler Accessed 30 August, 2016.

References Cited

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