Wet Weather and Advanced Treatment: Procurement · PDF fileStrategies to Secure the Right...
Transcript of Wet Weather and Advanced Treatment: Procurement · PDF fileStrategies to Secure the Right...
© 2013 O’Brien & Gere
Wet Weather and Advanced Treatment: Procurement Strategies to Secure the Right Technology
OWEA Annual Conference – Mason, OH – June 19, 2013, Operations, 11:00-11:45AM
Bill Meinert, PE, O’Brien & Gere
© 2013 O’Brien & Gere
Often The Situation
Maintain aging WW systems
Comply with effluent limits
Monthly average, weekly limit, instantaneous maximum
Achieve higher levels of treatment
Tighter limits, plus Annual or Seasonal nutrient removal allocations?
Consider innovative technologies (to name a few acronyms)
High Rate Flocculation Settling (HRFS)
Moving-Bed Biofilm Reactors (MBBR)
Integrated Fixed-Film Activated Sludge (IFAS)
Membrane Bioreactor (MBR)
Limited Qualified Providers
Technology, Equipment
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What Do You Do?
You Must
Ensure Compliance
Meet Project Goals & Objectives
Limit Capital Expenditures
Complete the Project on Time
Control O&M Costs
Alternative Contracting Methods can be part of the Solution
Cost, and “Or Equal”
› Funding Agency requirements (two, or none at all?)
› Significantly different? Re-design
› Potential sole-sourcing, costs, and vendor packaging
Schedule, accelerate to meet a deadline?
› Final Design, Construction Phasing
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Contracting Methods
Traditional Design / Bid / Construct
Base Bid / Alternate
Negotiate & Assign
Pre-Purchase Contract
Design-Build
Performance Guarantee
Main process, supporting systems
Overall Plant Performance
Average, Peak
Examples
Pros & Cons
Influencing Events
How the contracting method faired
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Example Project – MBR (Woodstock, VA)
System growth
Sludge disposal challenges
Consent order
Inflow
Interim operation plan
Chesapeake Bay Program
Permit renewal – Compliance, nutrient removal
3-4 mg/L TN, 0.3 mg/L TP
Project financing – Grant, Loan
Small secondary clarifiers
Limited aerobic digestion facilities
Actual floodplain
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Mobile MBR System
Construction sequencing (0.5-MGD unit)
Early training opportunity (0.5, 2-MGD)
Pre-purchase element (24-mo. rental)
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Before this … mobile
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2-MGD Expansion & ENR Upgrade | Basis of Design
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Anaerobic Anoxic Swing Aerobic1 Aerobic2 ZW Tank
WAS
Effluent
Methanol
Post AnoxicInfluent BOD
Ferric
DeOx
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Woodstock Experience
Pros & Cons
Had to do it – site, schedule, no full-scale competition
Base Bid awarded, cost escalation?
One experienced vendor – instead, do Negotiate & Assign?
Combined MBR and WAS Storage / Thickening technologies
Very forgiving, excellent effluent performance
Influencing Events
500-Year Flood, two weeks after startup
General contractor with limited experience, Direct line of communication
Growth evaporated with the economy (2008)
Second bioreactor for EQ, O&M cost control
How the contracting method faired
ENR Basis Of Design confirmation, O&M
Effective – design, construction, operation
› Training, training, training
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Example Project – SBR (Lock Haven, PA)
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Existing Plant
Some components >50-70 years old
New – Owner preferences – Weather protection, No moving parts in basins
New Plant
Old Plant
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Advanced BNR Upgrade | 3.75 MGD Plant
NPDES effluent limits –
25 mg/L CBOD
30 mg/L TSS
6 mg/L TN
0.8 mg/L TP
Nitrogen Removal
Sequencing batch Reactors (SBR)
Phosphorus removal
Chemical
› SBR (clarification)
› Tertiary filtration
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SBR Operation | Nutrient Removal
Anoxic fill
Denitrification
Oxic react
BOD removal
Nitrification
Coagulant addition
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Settle
Clarification
Decant
Effluent discharge
Idle
WAS discharge
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SBR Components
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Anoxic Fill
Multiple SBR tanks in different cycles
Effluent Decanter (floating, with submerged nozzles)
Jet Mixing & Aeration Headers
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Phosphorus Removal Processes | Tertiary Filtration
Four parallel tanks
Cloth-type disc filters
10 discs per tank
Sized for SBR decant rate (10.9 MGD)
5 min flocculation tank
Coagulant addition with flash mixing
Sized for future expansion
Sized for future lower TP limits (< 0.3 mg/L)
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Lock Haven Experience
Pros & Cons
Had to do it?
Base Bid awarded
Biological treatment and Aerobic digestion
Influencing Events
Project award delays due to funding
Further delays due to onsite MSW
Proprietary microwave UV and system re-design, change order
› Could contracting method have mitigated?
How the contracting method faired
Effective – No redesign, Coordinated I&C
Interlocking SBR & Cloth-Media Filter guarantees
Contract 1 documents and shop drawings for Contract 2 bidders
Precast offering ($), but … Piping supports and equipment clearances
On our fourth Manufacturer’s Project Manager!
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Example Project – IFAS (Massillon, OH)
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TP removal evaluation part of facilities plan update
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City of Massillon, OH | Roughing Filter-Ox. Ditch, Bio-P & Growth
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Removing the Roughing Filters for “odors” transferred BOD Load to Ditches, 1.2-MGD capacity increase and Bio-P zones were too much for the Ditches & Clarifiers.
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City of Massillon, OH | Roughing Filter-Ox. Ditch, Bio-P & Growth
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IFAS was good enough for BOD & Nitrification, but limited for Bio-P and Denitrification if unit redundancy was needed.
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Massillon Experience
Pros & Cons
It ain’t done yet!
BioWin & GPS-X Modeling and vendor sizing are beginning to correlate, finally!
Influencing Events
Project design award delays … same deadline
› Pre-purchasing will be necessary for acceleration
How the contracting method faired
We shall see … “Just 2” vendors may number 7 or 8 now
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Example Project – MBBR (Martinsburg, WV)
Qualifications, Life Cycle
Current (MBBR) & Future IFAS?) Bases of Design, plus CSO Treatment
Ranking & Scoring System
Impacts on other Elements
Integrating in final design
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Piloting | Moving-Bed Biofilm Reactor, w/ and w/o Nitrification
Piloted September 2011 – March 2012
Warm and cold
Dry and wet
Internal Recycle Adjustments
Air distribution & DO control
But … Secondary Underflow
› BOD-limited (add Carbon)
Period #1 - Nitrification MBBR – startup, warm & cold
› MBBR vs. Tower
Periods #2, 3 - DO in Tower Effluent – cold, baseline & adjusted carbon
› Pre- & Post-anoxic MBBR sizing
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Piloting | Supplemental Carbon
Carbon Source(s)
Acetic Acid used for Pilot, and Basis of Design
Alternatives
Design Feed Rates
Confirmed
Nitrification MBBR vs. Tower Effluent
Carbon Feed
› Approximately 3x with Tower
› But, Primary Effluent BOD:NO3-N 40% higher in Period #1, compared to #2 & #3
Deoxygenation Potential - SOUR Tests
› Little to no bio-activity to reduce DO
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Piloting | Influent & Primary Effluent Coagulant Jar Testing
Coagulant Testing – Ferric better than Alum
› Non-reactive P - 0.2 mg/L TP?
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Piloting | Analysis & Basis Of Design
Process Parameters Evaluated
TN Removal when BOD-Limited, Higher with Carbon to compensate
Minimum Wastewater Temperature Effects
Nitrification Check, Effect of DO on MBBR Process
Internal Recycle Rate (adjusted for Pilot influent conditions)
Coagulant Feed requirements for TP polishing
MBBR Surface Area Loading Rates (SALR) and SA Removal Rates (SARR)
› BOD, COD, NOx-N, NH3-N, TKN
Significant differences between the three leading MBBR vendor offerings
Pre-Purchase Contract Documents, Evaluated Bid Process
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Piloting & Pre-Purchasing | MBBR Layout
Pre-Purchase Contract Documents
Bid Form
› Total Capital – Furnish & Deliver
Breakdown – Media, Mixers, Aeration Diffuser System, Services
› Proposed Design – Volumes, Aeration, Mixing, %-Fill, Carbon
Evaluation of Bids
› 60% Total Life Cycle Cost
› 40% MBBR Supplier Qualifications & Experience
Technical Requirements & Constraints
› Footprint, “Tanks #1 & #2”
› Reserve %-Fill
› Contingency – Design Requirements for ENR
Performance Guarantee
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Nutrient Removal Flow Schematics with Biofilm Carriers
Fixed -film (MBBR), Integrated Fixed-film – Activated Sludge (IFAS)
Function of Process Configuration
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WWTP Upgrade Design (2012)
Procurement, Alternatives?, Distributed Design Elements, Option Bid
Scope of Supply
Guarantees
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Martinsburg Experience
Pros & Cons
Extensive knowledge gained through Piloting & Pre-Purchase
Performance guarantee fine-tuned
Construction sequencing and deadline not achievable without it
Option-Bidding the HRFS – will it work out, and within budget?
Modeling and vendor sizing not so good for MBBR
› Significant vendor differences
Influencing Events
Project budget
Uncertain funding agency requirements
How the contracting method faired
Effective – No redesign, Coordinated I&C
Interlocking MBBR & HRFS guarantees – and operating modes
Contract 1 documents and shop drawings for Contract 2 bidders
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Overall Experience, Opinions, Conjecture, Random Thoughts …
You have Options
Traditional design and bid as one contract
› List many or none, Establish the basis of design standard
Pre-Purchase, Negotiate & Assign, Design-Build
Nothing’s Perfect, Case-by-case Decision-making
Get What You Need, and Follow Public Procurement Requirements
Opportunity to Fit Technology with Overall Project (hand in glove)
Method to Meet Accelerated Schedules
Reduce Chances of Re-design (cost, time)
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OWEA Annual Conference – Mason, OH – June 19, 2013, Operations, 11:00-11:45AM
Bill Meinert, 4201 Mitchellville Road, Suite 500, Bowie, MD 20716, [email protected], (301) 731-1130