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

quivalent) M

GD

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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Miles Surveyed for Leaks

Monthly Cumulative Target

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July August September October November December January February March April May June

# of

val

ves

Main Line Valves Exercised

Target = 92 valves monthly or 1,100 annually

Water Distribution System Valves

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Type of Valve Inventory

#

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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rels

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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J A S O N D J F M A M J M

iles

Pipeline Cleaning

Hydraulic Cleaning Mechanical Cleaning

YTD Actual

Target = 3 miles monthly or 36 miles annually

Renewable Energy at MWRA

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Savi

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Savings and Revenue Totals for Renewable Energy Production, FY14

Solar Wind Hydro Steam


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, $ Renewable Energy Certificates (RECs) Values, FY14

Steam Hydro Wind Solar

Workforce Management

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1150

1170

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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


130,000,000

135,000,000

140,000,000

145,000,000

150,000,000

155,000,000

160,000,000

165,000,000

170,000,000

175,000,000

FY03 FY04 FY05 FY06 FY07 FY08 FY09 FY10 FY11 FY12 FY13 FY14

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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FY03 FY04 FY05 FY06 FY07 FY08 FY09 FY10 FY11 FY12 FY13 FY14

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

1.5

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STG Pow

er Outpu

t (M

W)

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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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


Presentation to the

Board of Directors

Deer Island Clarifier Rehabilitation Contract 7394

September 17, 2014

Deer Island Stacked Clarifiers

Condition of Concrete


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

Location of Access Pits

CFRP InstallaKon


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


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

massachusetts water resources authority - mwra - … 87 linear feet of 16-inch-diameter, cast-iron...

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