Energy Efficiency Projects for

Aeration Systems:• A Case Study of the Fox River

Water Reclamation District

James Kerrigan, P.E. – Fox River Water Reclamation DistrictRyan Christopher, P.E. – Greeley and HansenLaurissa Cubbage, P.E. – Greeley and Hansen

Presentation Topics

• Overview of Energy Usage at WRF

• Overview of the Fox River Water Reclamation District

• West WRF High Efficiency Aeration Improvements

• Albin D. Pagorski WRF Aeration System Improvements

• Grant Funding Availability

• Summary

Overview of Energy Usage at WRF

Source: Zahreddine, Phil, USEPA. “Innovative Energy Conservation Measures at Wastewater Treatment Facilities.” Power Point Presentation.

AERATION

54.1%

Fox River Water Reclamation District

• Provides wastewater treatment services to

over 180,000 residents in service area (City

of Elgin, Village of South Elgin)

• FRWRD treats average of 26 MGD across 3

WRFs– North

– West

– Albin D. Pagorski

West Water Reclamation Facility

• Online in 2004

• Design average flow 5.0

mgd

• Current average flow 3.1

mgd

• Designed for expansion

up to 25 mgd

West WRF – Aeration System

Background

• 3 Existing Multi-Stage Centrifugal Blowers– Blowers were oversized for

low flow situations

– Excess air was sent to off-line aeration tank

• Infrastructure Available for Denitrification– Tanks setup for

denitrification

– Equipment purchase required (mixers and recycle pump)

West WRF Existing Blower Room

West WRF – Aeration Blower

Technology Evaluation

• Comparison Between Turbo Blowers and Existing Equipment – Energy efficiency

– Operation and maintenance costs

– Capital costs

– Payback period

• Option 1 – New Turbo Blower, continue to send excess air to aeration tank

• Option 2 – New Turbo Blower, no excess air

• Option 3 – New Turbo Blower, no excess air and install denitrification

Air Flow Frequency

0.00%

2.00%

4.00%

6.00%

8.00%

10.00%

12.00%

14.00%

16.00%

18.00%

20.00%

Air Flow Frequencies

Option 3

Option 2

Option 1

Evaluation Recommendation

• Recommended Option 3

– Install One 150 hp Turbo Blower and install pump

and mixers to operate denitrification

• Total Construction Cost = $177,000

• $30k in annual energy savings

• $153,318 grant was awarded from two

agencies• 87% of construction cost for project came from grants

• Payback reduced to under 1 year with grant funding

High Efficiency Aeration Blower Project

High Efficiency Aeration Blower Project

West Plant Blower Power Reduction

New Blower Online

Old Blower Operation

– Approx. 40% Reduction in Power Usage

BNR Online

Albin D. Pagorski WRF

Aeration System Improvements

• Albin D. Pagorski WRF

– Daily average flow 16.0 mgd

– Design average flow 25.0 mgd

– Peak flow 50 mgd

• Existing blowers were past

useful life and have become

maintenance intensive

• No D.O. Controls, labor

intensive process

• New industrial load to plant

with high BOD concentration

ADP Aeration System Efficiency

Evaluation

• Comparison between existing equipment

and new equipment– Energy efficiency

– Operation and maintenance costs

– Capital costs

– Payback period

• Option 1 – New Turbo Blowers

• Option 2 – New Turbo Blowers with new diffusers

• Option 3 – New Turbo Blower, with new diffusers and

D.O. controls

Air Flow Frequency

0.00%

2.00%

4.00%

6.00%

8.00%

10.00%

12.00%

14.00%

16.00%

18.00%

20.00%

Air Flow Frequencies

New DO and Diffusers

New Diffusers Only

Existing Aeration System

ADP Aeration System Improvements

• Updated Plant Basis of Design

– Analyzed plant firm capacity, resulting reduction • 27,000 scfm to 20,800 scfm

• Evaluated blower combinations

• New DO Control System

– Pressure Based Dual Loop Control

• Sequencing

– Minimizing WRF interruption

Blower Combination – Selected

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

22,000

24,000

26,000

28,000

30,000

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

Air

Flo

w,

scfm

Percentile Frequency

Neuros 300 HP Option at Design Flow (25 mgd) with Fresh Express Peak Flow (0.80 mgd)

(Dirunal Variations Shown by Dashed Lines)

DAILY AVERAGE FLOW

DAILY MAXIMUM FLOW, 40% ABOVE AVERAGE

DAILY MINIMUM FLOW, 50% BELOW AVERAGE

1-300HP

2-300HP

BLOWER RANGE300HP: 2,353 to 5,369 scfm

MinimumFlow Envelope

Firm Capacity

3-300HP

4-300HPMaximum Flow Envelope

ADP ASI – Project Update

• $2.4 million construction cost

– 5 Turbo Blowers with associated electrical upgrades

– Dissolved oxygen control system

• Fine bubble diffusers (under separate contract)

• Substantial Completion April 2015

• Final Completion May 2015

• Grant Funding

ADP ASI – Project Update

ADP ASI – Project Update

ADP WRF Power Reduction

All New Blowers Online

Old Blowers Operation

Grant Funding

• Both projects received grant funding through ICECF and DCEO

– West WRF• $45k from ICECF

• $108k from DCEO

– ADP Aeration System Improvements• $208k from ICECF

• $612k from DCEO

– (Diffuser replacement required to receive full funding)

• Total Grant Funding

– $973k awarded to both projects

Summary

• Aeration system efficiency improvements can greatly reduce operational costs

• Grant funding is available to push projects that fight for funding with more conventional projects

• FRWRD Projected Annual Energy cost savings

– Total = $167,400

• Simple Payback

– Under 10 years

Lessons learned

• Blower Manufacturer Differences

– Controls of blowers, valve operation

– Selected blower more cost effective even with slightly lower efficiency

• Integration Needs Careful Consideration

• Design to Include Staging of Demolition

• Staff Training

• Flow Meters

• New Check Valves

Questions

• Acknowledgments

– Fox River Water Reclamation District

• Bob Trueblood

• Beth Vogt

• Doug Haacker

• Dave Green

– Greeley and Hansen

• Andy Martin