Massachusetts Water Resources Authority - MWRA - … 87 Linear Feet of 16-Inch-Diameter, Cast-Iron...
Transcript of Massachusetts Water Resources Authority - MWRA - … 87 Linear Feet of 16-Inch-Diameter, Cast-Iron...
Massachusetts Water Resources Authority
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J A S O N D J F M A M J
Inches (Water E
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Plant Flow & Precipitation
Total Plant Flow, MGD 12 Yr Avg Flow, MGD Total Precipitation, inches rain 12 Yr Avg Precipitation, inches rain
Deer Island Operations
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Deer Island Yearly Maintenance Metrics
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Rep
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Replacement Asset Value / Maintenance Technician
Best in Class Target = $8 to $10 Million
Water Distribution System Pipelines
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# of
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Main Line Valves Exercised
Target = 92 valves monthly or 1,100 annually
Water Distribution System Valves
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Type of Valve Inventory
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Operable Percentage
FY14 to Date FY14 Targets Main Line Valves 2,092 97.7% 95%
Blow-Off Valves 1,206 95.1% 95% Air Release Valves 1,335 93.1% 95%
Control Valves 48 100.0% 95%
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# of
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Inverted Siphon Cleaning
Monthly Cleaning
YTD Actual
Target = 3 monthly or 36 / 33% of the system annually
Wastewater Pipeline and Structure Inspections and Maintenance
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Pipeline Cleaning
Hydraulic Cleaning Mechanical Cleaning
YTD Actual
Target = 3 miles monthly or 36 miles annually
Renewable Energy at MWRA
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J A S O N D J F M A M J
Savi
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Savings and Revenue Totals for Renewable Energy Production, FY14
Solar Wind Hydro Steam
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Steam Hydro Wind Solar
Workforce Management
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Filled Position Tracking
Target Filled
Pr/Trns Hires Total
FY11 48 (62%) 30 (38%) 78
FY12 42 (61%) 27 (39%) 69
FY13 82 (64%) 47 (36%) 129
FY14 111 (69%) 51 (31%) 162
69% 31%
Positions Filled by Hires/Promotions FY14-YTD
Promotions / Transfers (111)
Hires (51)
Presentation to the
Board of Directors
Existing and Future Combined Heat and Power (CHP)
at DITP
September 17, 2014
Massachusetts Water Resources Authority
130,000,000
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Total DITP Annual Power Demand, kWh
DITP – A Significant Energy User
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Staff efforts have helped reduced plant electrical demand by 10% • Process Optimization • Installation of new energy efficient equipment
DITP – Green Energy Production (FY14)
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Maximizing On-Site Green Energy Production is a priority for MWRA • 23% of DITP’s total electricity demand met by green energy
• 60% of DITP’s energy needs (heat + power) met by Digester Gas (62.5% for all)
Generation Assets:
• Digas – STG/BPSTG – 25.1 M kWh – 17.4%
• Hydro Power – 5.89 M kWh – 4.1%
• Wind Power – 1.48 M kWh – 1.0%
• Solar – 0.86 M kWh – 0.6%
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Total On-‐Site Renewable Electrical Energy Produc@on, kWh
Renewable energy from Digas Renewable Energy from other sources
• Anaerobic Digestion: – 240 dtpd solid in, 100 dtpd to FRSA for pellet conversion – Digas generated on average is 60% methane
• OSTPP: Bottom-Cycle Generation – Digas – 95% utilized – 95% of heat demand met by Digas ($17.6 million annually) (remainder by Fuel Oil) – 25.1 M kWh generation from Steam Turbine ($2.4 million annually)
DITP – Digester Gas Generation & Use (FY14)
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On-site Thermal Power Plant
Anaerobic Digester Complex Digas Generation
• Bottom Cycle Generation – Heat First – 60% efficient
• Generate Steam then Hot Water
– Power Second – 9% efficient • Generate Electricity from Steam
• New BPSTG / Steam Bypass Valve improves steam to electricity conversion process by extracting more heat per unit steam
Combined Heat & Power Process – Currently Used by DITP
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• New BPSTG / Steam Bypass Valve improve steam to electricity conversion process
– 18% improvement (10.6% efficiency overall) – +1.3 MW increase in generation from steam generators – Sustainable May - November – Should see an increase of +4.5 M kWh / year – ~30 M kWh total/year from steam (25.1 M kWh currently)
Combined Heat & Power Process – Improved Performance
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y = 0.0706x -‐ 0.6165 R² = 0.97744 y = 0.0729x -‐ 1.9051 R² = 0.99959
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STG Pow
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STG Power Output vs. Steam Flow (STG Boiler 101 with BP-‐STG)
OperaKng in a vacuum Not operaKng in a vacuum
Steam Flow (KLB/HR)
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• Develop engineering and economics for new CHP
• Compare and recommend more efficient generation technologies
• Internal Combustion Engines
• Gas Turbines
• Develop Simple Payback Analysis / Economic benefits
• Evaluate implementation options
CHP Study Objectives – CDM Smith Residuals Technology Assessment
Internal Combustion Engines versus Gas Turbines
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• Exhaust emissions (NOx, CO) – GT ↓ • Space required (Capacity) – GT ↓ • Capital and operating costs – GT ↓ • Energy efficiency (Electricity and Heat) ↔ • Flexibility – GT ↑
CHP Technology Change
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CHP Benefit from Co Digestion • Expected 29-42% increase in biogas • Results in more electrical output • Heat demand increase 5-10% • Electrical demand increase <2%
CHP Technology Change • Change from Bottom to Top cycle generation • Improve efficiency • Increased electrical production • Better use of all digas - summer months • Continue to meet plant heating needs
Cost Benefit Analysis – Simple Payback
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Parameter OSTPP with
1 Gas Turbine*
OSTPP with 1 Gas Turbine*
With Co-digestion
3 Gas Turbines* 3 Gas Turbines*
With Co-digestion
Capital Cost $24.9 M $24.9 M $75.0 M $75.0 M
Annual O&M Cost $2.2 M/yr $2.2 M/yr $1.6 M/yr $1.6 M/yr
Annual Electrical Savings $5.2 M/yr $7.0 M/yr $11.4 M/yr $14.7 M/yr
Net Annual Savings $3.0 M/yr $4.8 M/yr $9.8 M/yr $13.1 M/yr
Simple Payback Period 8 years 5 years 8 years 6 years
Payback Without and With Co-Digestion
• Single Gas Turbine capacity: 4.6 MW • Payback does not include potential funding for green energy projects to pay for the capital.
Potential Energy Benefit with CHP
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• 23% green generation* (18% w/digas) • 75% purchased electricity
• Can reverse energy profile • More sustainable • 77% green generation* (72% w/digas) • 21% purchased electricity
CHP with 3 Gas Turbines – Co-Digestion
Existing Thermal Plant
*Note: 1.5% generation by CTG backup power.
• Gas Turbine CHP is recommended technology
• Staff will move forward with design to – Confirm economics – Investigate additional equipment needed – Review economics with and without co-digestion – Confirm full implementation approach – Develop specific gas system changes – Develop plans and specs for bidding new CHP
Recommendation
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Massachusetts Water Resources Authority
Presentation to the
Board of Directors
Struvite , Scum, Sludge, and Grit Removal Contract
September 17, 2014
Struvite Removal
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Cause • Struvite forms a pipe scale and consists of phosphate, ammonia, and magnesium
• Struvite coats digested sludge pipelines • Digester overflow box piping • Centrifuge piping
• Difficult to remove PrevenKon • Ferric chloride added to control RemediaKon • Specialized equipment and services in confined spaces needed for removal
Scum, Sludge and Grit Removal
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• Removal of severe blockages beyond in house capability in:
• Gravity thickeners • Primary clarifiers
• Influent channels • Scum receiving wells
• Vactor trucks and boxes used • Off site material disposal
Massachusetts Water Resources Authority
Presentation to the
Board of Directors
Deer Island Clarifier Rehabilitation Contract 7394
September 17, 2014
Deer Island Stacked Clarifiers
Condition of Concrete
Massachusetts Water Resources Authority
Presentation to the
Board of Directors
Beacon Street Line: Water Pipeline Repair
Contract 7474
September 17, 2014
Beacon Street Line - Brookline
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• 48-inch cement mortar lined cast-iron pipe
• Constructed in the 1870sIt is part of MWRA’s Boston Low Service System
• A significant portion of it is located underneath the MBTA’s Beacon Street Green Line tracks
• The Beacon Street Line provides important the Longwood Medical area
Beacon Street Line - Brookline
Beacon Street Line - Brookline
Location of Access Pits
CFRP InstallaKon
Massachusetts Water Resources Authority
Presentation to the
Board of Directors
Spot Pond Water Storage Facility Contract 6457, Change Order 7
September 17, 2014
Spot Pond Tank and Ravine Road Piping
Remove Ledge to Install 36-Inch Pipelines and Valve Vaults at Ravine Road
Remove 87 Linear Feet of 16-Inch-Diameter, Cast-Iron Water Main and Replace with Restrained-Joint, Ductile-Iron Pipe
Current Progress
Massachusetts Water Resources Authority
Presentation to the
Board of Directors
Gillis Pump Station Short-Term Improvements Contract 7260, Change Order 3
September 17, 2014
Additional Valve Work
Ledge Croppings Inside Excavated Pit
Selector Switch for Three VFD Bypasses