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  • Biosolids Dryer Facility: Successfully

    Managing a Public-Private Partnership

    Luther Blackburn, MS Manager – Wastewater Operations

  • Biosolids Dryer Facility (BDF) P3 Agenda

    Great Lakes Water Authority and Biosolids Dryer FacilityBackground

    P3 Contractual ElementsContract

    Biosolids Thermal Drying ProcessProcess

    The 3rd “P” in P3Partnership

    Unique Challenges and How P3 Overcame ThemChallenges

  • Wastewater System

    3 Main Interceptors

    2.9 million People served

    9 CSO Facities

    5 Pump stations

    988 Square mile service area

    181 Mile conveyance system with trunk sewers and interceptors

    87 Member partners serving 77 individual communities

    1 WRRF

    Quick Facts: Great Lakes Water Authority

    1,700 MGD Treatment capacity

    https://www.bing.com/images/search?view=detailV2&ccid=2CWIuzmr&id=7B2C4DEB684AE055689C9DD25C44E461ECB1347E&thid=OIP.2CWIuzmrDMebm6IIxuFRlQHaHb&mediaurl=https://www.clker.com/cliparts/g/t/v/v/2/d/pouring-water-hi.png&exph=596&expw=594&q=Sewage+Clip+Art&simid=608052021418395560&selectedIndex=20

  • Largest single-site Water Resource Recovery Facility in North America!

  • GRAVITY

    THICKENING

    SLUDGE

    STORAGE

    INCINERATION & ASH

    DISPOSAL

    CENTRAL

    OFFLOADING

    DEWATERING

    BFPs

    CENTRIFUGE

    S

    PRIMARY

    SLUDGE SECONDARY SLUDGE

    BIOSOLIDS DRYER FACILITY

    WRRF Solids Handling Pre-BDFPost-BDF

  • ?

    Processing Capacity Permit req’d. 850 dtpd

    Sludge Storage Limited capacity

    Sludge Offloading Limited capacity

    Landfills Limited nearby space

    MACT 129 Compliance Requires MHF upgrades

    1940 MHFs At end of useful life

    Sustainability Desire to be eco-friendly

    Drivers for the Biosolids Dryer Project

  • Drivers for a Public Private Partnership

    P3

    Single Source

    D/B and O/M 1

    Faster Project Completions Contract measure of performance / profit

    Specialized Expertise Experience, Knowledge and Skills

    Budget Certainty Fixed Fee, Contracted

    Quantity

    Greater ROI Innovative design and financing approaches

    Risk Transfer Operational/execution risks fall to the private participant

  • MAR 2012 MAY 2013 MAY 2014AUG 2012

    BIOSOLIDS SYMPOSIUM

    Evaluated technologies.

    Recommended BDF for its beneficial product re-use.

    REQUEST FOR

    PROPOSAL

    Advertised for Design- Build-Operate-Maintain of biosolids dryer facility.

    DESIGN COMPLETE

    AUG 2015

    CONSTRUCTION

    COMPLETE

    By contract, NEFCO takes the lead w/ limited GLWA input.

    BDF Design/Build Timeline

    CONTRACT AWARD

    NEFCO leads D/B team.

    NEFCO provides 20 yr O/M.

    Completion 6 months before contract date.

    JUMP JUMP

  • AUG 2015 FEB 2016 TODAYOCT 2015

    SYSTEM TESTING

    Trains tested one-by-one

    5-DAY DEMONSTRATION

    All 4 trains tested together, at capacity, for 5 days, 24 hrs/day

    3 YEARS OF SUCCESFUL

    OPERATION

    In 2018, BDF processed 70% of WRRF sludge

    BDF Operating Timeline

    COMERCIAL OPERATION

    Began operation, typically with 2 to 3 trains in service at a time

  •  Located across the street from the WRRF

     Four dryer trains 316 dtpd firm capacity (420 dtpd peak)

    Dewatering included in the facility operation

    Biosolids Dryer Facility Today

  • Solids Generation and Disposal

    Before BDF

    MHF 67%

    Land App 11%Landfill

    22%

    After BDF

    BDF 70%

    Land fill 1%

    MHF 29%

  • Average Dry Tons/Year:

    135,000

    Annual O&M savings:

    $14.6 M

    20-year O&M savings:

    $292 M (in 2013 dollars)

    Payback period on

    $143 M capital cost:

    9.8 years

    O&M Savings per Dry Ton Using Dryers

    $338 /dry ton

    $384 /dry ton

    $490/dry ton

    COF (Hi) $350

    Dewatering $140

    COF (Lo) $244 Incineration

    $198

    Dewatering $140

    Dewatering $140

    $229 /dry ton

    BDF $229

  • Biosolids Thermal Drying Process

  • Biosolids Thermal Drying Process

    FURNACE

    MIXER

    DRYER DRUM

    COMBUSTION FAN

    SEPARATOR

    SCREENER

    CRUSHER PELLET

    COOLER

    PNEUMATIC TRANSPORTER

    RECYCLE BIN

    TRAY SCRUBBER

    CAKE BIN

    MAIN FAN

    RTO FAN

    RTO COMBUSTION

    FAN

    RTO

    TO STACK

    TO SILO

  •  Proven Technology

     No additional need for bulk chemical

    addition to stabilize cake

     Class A EQ Product with multiple outlets.

     Nutrients in biosolids remain after drying

    – product suitable for beneficial re-use

     Nutrients in biosolids not water soluble –

    No runoff

    Thermal Drying Product

  •  Bulk land application

     Fertilizer blending

     Land Reclamation

     Alternate Fuel

     Cement kilns

     Power generation

     Renewable fuel

    End Uses for Dried Biosolids

  • Challenges Test the Strength of a Partnership

  • Startup challenges

     Demonstration testing and equipment performance prior to

    commercial operations

     Dryer drum vendor went out of business amidst design issues

    Processing challenges due to variable and low-density sludge

     Adjusted design of solids handling equipment

     Modifications to ensure process safety

    Environmental compliance challenges

     Sulfur dioxide treatment retrofit for air emission compliance

     Poor Land application BMPs lead to dust and odor concerns

    Challenges During Startup & Initial Operations

  • Testing Challenges and How P3 Overcame

    • P3 approach to challenges:

    • Testing protocol and “rules of engagement” developed mutually

    • Open communications during testing

    • Test reports and expedited review/comment response

  • Performance Testing Challenges

    A range of Primary & Secondary sludge blend ratios needed to be tested, but

    abrupt changes impaired BDF operation

    A range of ratios were tested, but ratio changes were made gradually and after

    mutual agreement

    Insufficient sludge was available to support a required 5-day demonstration with 4

    dryer trains simultaneously in operation

    WRRF sludge inventory management prioritized BDF operations to ensure

    adequate sludge available for testing

    Mutually agreed upon pause in testing based on sludge inventory and %TSS

  • Production Challenges

    Low density dried product led to:

    Plugging in separator discharge

    equipment and piping

    Piping and divert valve under

    separator redesigned

    Recycle bin thermal hot spots

    Recycle bin discharge

    redesigned

    Installed inline % solids

    instrument in sludge pipe

    entering BDF

    BEFORE AFTER

  • Air Emissions Compliance Challenges

    SO2 concentrations in the stack exhaust intermittently

    peaked above permit limits

    Performed diagnostic testing to establish model

    Installed continuous emissions monitors (CEMs) on

    all 4 dryers

    Installed packed tower scrubbers after

    regenerative thermal oxidizers (RTOs)

  • Land Application Challenges

    Class A dried biosolids land application is new in Michigan. The inexperienced land

    application contractor chose poor sites and used spreading practices that led to

    unacceptable offsite dust and odors

    Adopted 90% incorporation to reduce odors

    MWEA developed Best Management Practices

    NEFCO replaced land application contractor

  • Ongoing Improvements

    Main burner tuning

    Screener optimization for removal of fibrous material

    Chemical suppressant isolation system being installed

    Carbon monoxide detectors being piloted

    Sludge solids meter being installed for consistent dryer feeding

    Pug mill optimization for particle size

    Air flow optimization

  • Partnership – The 3rd “P”

  • P3

    Elements of a Successful P3

    Conflict Resolution ‘Win, win’ outcomes

    Communication Open & collaborative

    Trust Earned, mutual, two-way

    Work Relationships Developed & Maintained

    Risks/Benefits Mutually shared

    Contract Execution Delivered by both parties

    Goals Shared Vision

    JUMP

    JUMP

  •  Allowed for commercial operations to commence without meeting all

    contractual requirements

     Lower throughput guarantees due to equipment bottlenecks

     Revised liquidated damages mutually developed

     NEFCO responsible for alternative disposal as needed

     Equipment upg