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Evaluating the Future of Biosolids Drying: Louisville MSDs Decision Robert Bates Louisville Metropolitan Sewer District March 3 rd , 2015

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Evaluating the Future of Biosolids Drying: Louisville MSDs Decision

Robert Bates Louisville Metropolitan Sewer District

March 3rd , 2015

History MSD has been drying biosolids at the Morris Forman Water Quality Treatment Center since 2001 , and actively marketing since 2004 All solids generated at five regional facilities in Louisville & Jefferson County are transported to MFWQTC by truck or force main

MFWQTC processes approximately 25,000 dry tons per year of biosolids with the majority of final product historically being used by bulk agriculture

Morris Forman Solids Processing Additions / Improvements

Digestion – converted solids storage tanks to anaerobic digesters

Dewatering – 5 High Solids centrifuges

Drying – 4 Drum Drying Systems – largest capacity in US at the time

Dewatering Wet Well

Polymer

Dewatering Centrifuges(5)

Wet Bin(4)

Recycle Bin(4)

Mixer(4)

Furnace/ Drum(4)

Preseparator/ Polycyclone

(4)

Shaker/sizing(4)

Crusher(4)

Recycle Solids

Pellet Cooler(4)

Pneumatic Transporter(4)

Storage Silo(2)

Natural Gas

Nitrogen Storage/Evaporation

N2

N2

RTO(4)

Main ID Fan(4)

Venturi Draft Fan(4)

Exhaust to atmosphere

Condenser

Venturi Scrubber

TWAS

Digesters

DAFT (8)

Polymer

Blend Tanks N/C

N/C

From Primary

From RAS/WAS

Process Water Dewatering Wet Well

DG

Flare

HW

Solids Receiving Tank Trucked Sludge

Overflow to Primary

HW

DG

Solids Process Flow Diagram

Overflow to Primary

MSD first produced biosolids pellets in late 2001

By April 2002, most solids were pelletized. Although solids were still

going to the Landfill, the reduced volume meant an immediate cost

savings for MSD.

Biosolids to Landfill

0

50

100

150

200

250

300

350

400

Jan-

02

Jan-

02

Jan-

02

Fe

b-0

2

Fe

b-0

2

Ma

r-0

2

Ma

r-0

2

Ap

r-0

2

Ap

r-0

2

Ma

y-0

2

Ma

y-0

2

Date

To

ns

pe

r D

ay

Wet Tons Pellet Tons

$5000 - $6000 / day Landfill costs

$800 - $1000 / day Landfill costs

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2007 2008 2009 2010 2011 2012

Pellets to Beneficial Use Pellets to Landfill Wet Cake to Landfill

Annual Biosolids Disposition by Form (by %)

Increased equipment

wear and tear, and

major maintenance,

limited drying

equipment availability.

100%

0% 2013

Complete Beneficial Use

Coordination with Marketer allowed for distribution of material previously disposed of in the landfill

But,

And there’s always a but………. MSD had a decision to make regarding the future of biosolids drying.

Courtesy of Cornerstone Engineering, Inc.

Courtesy of BTM Engineering, Inc. Maintenance & Money

Preseparator Replacement

NEED

Thermal Oxidizer Manifold

WANT

MAINTENANCE vs

IMPROVEMENTS

Industrial Waste Department SIUs

Trunk Line Monitoring

Morris Forman Influent Nickel Data

0

500

1000

1500

2000

2500

3000

11/1

/2008

11/8

/2008

11/1

5/2

008

11/2

2/2

008

11/2

9/2

008

12/6

/2008

12/1

3/2

008

12/2

0/2

008

12/2

7/2

008

1/3

/2009

1/1

0/2

009

1/1

7/2

009

1/2

4/2

009

1/3

1/2

009

2/7

/2009

2/1

4/2

009

2/2

1/2

009

2/2

8/2

009

3/7

/2009

3/1

4/2

009

3/2

1/2

009

3/2

8/2

009

4/4

/2009

4/1

1/2

009

4/1

8/2

009

4/2

5/2

009

Po

un

ds p

er

day

Louisville Green Nickel Data

0

200

400

600

800

1000

1200

1400

1600

1800

10

/29

/08

10

/30

/08

10

/31

/08

11

/1/0

81

1/2

/08

11

/3/0

81

1/4

/08

11

/5/0

81

1/6

/08

11

/7/0

81

1/8

/08

11

/9/0

81

1/1

0/0

81

1/1

1/0

81

1/1

2/0

81

1/1

3/0

81

1/1

4/0

81

1/1

5/0

81

1/1

6/0

81

1/1

7/0

81

1/1

8/0

81

1/1

9/0

81

1/2

0/0

81

1/2

1/0

81

1/2

2/0

81

1/2

3/0

81

1/2

4/0

81

1/2

5/0

8

2/1

9/0

92

/20

/09

2/2

1/0

92

/22

/09

2/2

3/0

92

/24

/09

2/2

5/0

92

/26

/09

2/2

7/0

9

3/1

2/0

93

/13

/09

3/1

4/0

93

/15

/09

3/1

6/0

93

/17

/09

3/1

8/0

93

/19

/09

3/2

0/0

93

/21

/09

3/2

2/0

93

/23

/09

3/2

4/0

93

/25

/09

3/2

6/0

93

/27

/09

3/2

8/0

93

/29

/09

3/3

0/0

93

/31

/09

4/1

/09

4/2

/09

4/3

/09

4/4

/09

4/5

/09

4/6

/09

4/7

/09

4/8

/09

4/9

/09

4/1

0/0

94

/11

/09

4/1

2/0

94

/13

/09

4/1

4/0

9

mg

/kg

2008-2009 Nickel “event” Product Analysis / 503s

Market Demands & Weather

August 4, 2009

Rain Snow Frozen Ground Flooding

http://water.epa.gov/scitech/wastetech/biosolids/guide.cfm

Decision Point

Dryers were just over 10 years old

Largest Capital Project in MSD history at the time

Land application of biosolids environmentally sound

Avoided landfill costs

Potentially save 8 – 10 employee positions

Dryers were increasingly labor intensive Landfilling cake or pellets potentially cheaper Capital improvements needed to continue drying Utility costs harder to project / budget Potential write of ~$22 Million in assets

Decision Point Directions

MSD Board requested a business case study of solids processing & disposal options with third party review

Options evaluation based on: Historical trends in natural gas and electricity costs Average LG revenue over past 5 years Labor costs specific for each alternative Maintenance costs based on historical costs plus

annualized projections of major rebuild/replacement

Evaluate 3 Options: 1. Landfill dewatered biosolids (not pellets) 2. Landfill dried biosolids (low-grade pellets) 3. Continue marketing Louisville Green

MSD Staff Recommendations:

– Continue to produce and market Louisville Green

– Pursue high dollar markets

– Make needed repairs to reliably produce Louisville Green pellets

Moving Forward

Board Decision: Issue a Request for Proposals for Distribution and Marketing of Louisville Green but directed consideration of alternative approaches to LG marketing, to see if lower cost options existed

Competing Interests?

Green vs Green aka

vs

MSD entered into a contract with a marketer and continues to distribute Class A, EQ biosolids

What it really cost to process solids by disposition method

By The Numbers Today

Total Processing Unit Cost

3.8% 1.2%

3.8 % more for pellets to landfill 1.2% more for pellets to market

Competing Interests?

Green vs Green aka

vs

Engineered silver nanoparticles (AgNPs) <20nm 20 – 15,000 silver atoms An emerging environmental contaminant of concern Antimicrobial properties Consumer products is increasing rapidly Enter terrestrial ecosystems through land-application of biosolids Microbial communities in organic matter and nutrient cycling in ecosystems

Soaps, toothpaste, shampoo, kitchenware, pencils Lipophilic-readily available for absorption and bioaccumulation in fatty tissues Antimicrobial properties Photodegrades Public pressure causing manufacturers to remove from products Minnesota bans triclosan from consumer and PPCPs

Triclosan / Triclocarban

AgNP

Pharmaceuticals and Personal Care Products (PPCPs)

PPCPs include: Prescription and over-the counter therapeutic drugs Veterinary drugs Fragrances Cosmetics Sun-screen products Diagnostic agents Nutraceuticals (e.g., vitamins) Sources of PPCPs: Human activity Residues from pharmaceutical manufacturing (well defined and controlled) Residues from hospitals Illicit drugs Veterinary drug use, especially antibiotics and steroids Agribusiness

What is the future of biosolids? Truly an “A” to “Z” approach: Digestion Conditioning Thickening Dewatering Minimization Resource Recovery Nutrients Heat Energy Disposition

Compliance

Source

Purpose

Robin Burch Joe Falleri

Sharon Worley Alex Novak

Thank you!