Item 1. W WWTF 60% Design Progress ReportCouncil Study Session:
West WWTF –60% Design
Presented by: Advanced Engineering and Environmental Services, Inc. (AE2S)
November 2021
West WWTF: Schedule
•Preliminary Design January-June 2021
•MBR Pre-Procurement April 2021
•60% Design July-Nov 2021
•90% Design Nov 2021 –Feb 2022
•Final Design March-April 2022
•Bidding May 2022
•Construction Initiation June 2022
•Substantial Completion November 2023
•Final Completion December 2023
West WWTF / Project Quick Facts
•Original Design/Construction: 2003/2004
•REC Capacity (flow based)
–Current: 3,428
–Post-Project:8,057
–Ultimate Buildout: 24,000
•Treatment Type
–Current: Bio-P Oxidation Ditch
–Proposed: Full BNR Membrane BioReactor
Odor Mitigation
Area / Building Current Future (2023)
Pretreatment GAC New GAC
Fine Screen Building (New)N/A New GAC
Pre-Aeration Tanks Covered Covered (New Tanks)
WAS Thickening Indoors Indoors (no change)
Aerobic Digestion GAC GAC (no change)
Solids Storage Tank Remain Empty Remain Empty
TWAS Loading Outdoors Indoors, Only Bottom Fill
Noise Mitigation
Area / Building Current Future (2023)
Pretreatment Odor Fan Fence Sound Enclosure
FSB Odor Fan (New)N/A Sound Enclosure
Digester Odor Fan Sound Enclosure Sound Enclosure
OxDitch Motors No Mitigation Decommissioned
Existing Digester Blowers Indoors Indoors (no change)
Process Blowers (New)N/A Indoors
Membrane Blowers (New)N/A Indoors
Effluent Aeration N/A Passive Aeration
Funding Overview
•State Revolving Fund (SRF)
•PPL Score Improvement = Fundable Range
•Green Project Reserve (GPR)
•Point Source Implementation Grant (PSIG)
•“Community Project Funding”
•Federal Infrastructure Bill
•SRF Capitalization, Specific Funding
Regulatory / Permitting
•NPDES Permit Re-issuance (main permit)
–Preliminary Effluent Limits
–Chloride Variance
–Anti-Degradation Study
–Environmental Assessment Worksheet
•General stormwater, etc
SITE LAYOUT
West WWTF: Rendering
PRETREATMENT BUILDINGS
SECONDARY BIOLOGICAL TREATMENT
Membrane Treatment Building
Administration Building
Administration Building
Costs and Phasing
DESCRIPTION
WEST LIQUID
PHASE 1 (WL1)
Sept. 2020
WEST LIQUID PHASE 1
(WL1) 30% DESIGN
WEST LIQUID PHASE
1 (WL1) 60%
DESIGN
Mobilization $1,402,000 $2,073,000 $2,071,574
Site Work $1,247,000 $1,738,000 $2,880,000
Influent Pump System $300,000 $226,000 $50,000
Preliminary Treatment Building $1,404,000 $1,077,000 $1,003,890
Fine Screen Building $2,565,000 $3,578,715
Convert Existing OD to Anaerobic Selector $348,000
Secondary Biological Treatment (SBT)$5,691,000 $6,197,550
Blower Building (BB)$1,050,000 $1,240,980
Membrane Treatment Building (MBT)$9,325,000 $5,500,000 $7,947,825
Tertiary Treatment Building (UV)$271,631 $412,000 $115,000
Effluent Aeration $546,000 $438,000 $201,260
Administration Building $1,650,000 $2,237,000 $2,802,795
PTB Biofilter Odor Control $312,592
Electrical $2,311,000 $2,550,000
Mechanical $1,232,000 $1,833,500
Instrumentation and Controls $1,078,000 $1,100,000
SUBTOTAL $21,427,233 $28,490,500 $28,089,589
Construction Contingencies $2,678,000 $2,849,000 $2,808,959
Undeveloped Construction Details $1,607,000
CONSTRUCTION SUBTOTAL $25,712,223 $31,339,500 $30,898,548
Engineering, Legal, Admin $4,371,000 $4,600,000 $4,600,000
OPINION OF PROBABLE COST $30,080,000 $35,940,000 $35,498,548
2021 (7.5% ENR Adjustment)$32,336,000 $35,940,000 $35,498,548
2022 (Additional 3% to Spring 2022)$33,306,000 $37,018,000 $36,563,505
COST DIFFERENCE $0 $3,712,000 $3,257,505
Potential GPR Grant ~$700,000
Costs and Phasing
•Phasing Options
Project Area Potential Modification
Potential Cost
Reduction Savings
Influent Pump System Reduction in improvements for PH1 $182,700 Deferred Cost
Secondary Biological Treatment (SBT)Reduce to two trains for PH1 $1,948,800 Deferred Cost
Tertiary Treatment Building (UV)Alternate UV option $60,900 Reduced Cost
Effluent Aeration Alternate EA option $304,500 Reduced Cost
Administration Building For Discussion TBD Deferred Cost
Total $2,496,900
Solar Array
•Summary –electricity is too inexpensive
($0.0593/kwh plus demand)
•Requires high assumed YoY electrical rate
increases
•East Facility
–Xcel program pays back higher rate for solar
incentive ($0.06/kwh “bonus”)
Solar Array
($200,000)
($150,000)
($100,000)
($50,000)
$0
$50,000
$120,000 $140,000 $160,000 $180,000 $200,000 $220,000 $240,000 $260,000 $280,000
Net Cumulative Cash Flow at the end of 20-year period“Profit” at End of 20-year period Given Electric Rate Increase and
Initial Capital Cost
2.43%3.50%5.00%
QUESTIONS?
Otsego City Council Update
WEST WWTF DESIGN
•Construction Costs -Uncertain
•Concrete
•Materials
WEST WWTF DESIGN -COSTS
•ENR CCI –Construction Inflation
•Building Cost Index –10.4% (12-mo)
•Construction Cost Index –5.2% (12-mo)
•“Composite” –7.5% (is that enough??)
June 2021 Water/Wastewater Bids*
Engineer's Estimate Low Bid +/-
Northern MN (2 projects)$ 34,800,000 $ 44,246,508 Over 27%
Central MN $ 5,000,000 $ 5,974,000 Over 19%
Southern MN $ 22,000,000 $ 26,765,800 Over 22%
*data courtesy of RLCG
SOLIDS BUILDING –MODEL/RENDERING
PROCESS FLOW DIAGRAM