CITY OF BALITMORE DEPARTMENT OF PUBLIC WORKS BACK RIVER WWTP

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CITY OF BALITMOREDEPARTMENT OF PUBLIC WORKSBACK
RIVER WWTP

• ENERGY INITIATIVES AND
• INNOVATIVE PRACTICES

Sheila Dixon, Mayor David E. Scott,
Director Nicholas H. Frankos, Plant Manager
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Presentation Outline

• Plant Overview
• Water Reuse
• Potable Water Conservation
• Electrical Distribution Upgrades
• Performance Based Energy Contract
• BGE Load Response Program
• On-Site Bleach Generation
• Future Energy Considerations

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Back River WWTP

• Built in 1907 on 466-acre tract located in
  eastern Baltimore County
• Design flow 180 MGD
• Average flow 140 MGD
• 140 sq. mile service area/1.3 million customers
• Two outfalls-Back River and Sparrows Point
• Annual O M budget - 50 million
• 300 employees
• Removal Efficiencies FY-08
• BOD 99, SS 99, TP 94, TN 68

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PLANT AERIAL VIEW
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BACK RIVER FACILITIES
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Water Reuse Overview

• Sparrows Point approached City to use Back River
  effluent for process water at steel plant.
• In 1941 Back River and Sparrows Point Steel Plant
  entered into a Water Reuse Agreement.
• SP currently takes approximately 40 MGD of Back
  Rivers final effluent.
• SP reimburses the City for electrical, chlorine
  and water costs 950,000 per year.
• Current steel plant owner is Severstal

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BS Sparrows Point PlantBackground

• Built in 1887 on 3500 acre tract of land with
  frontage on the Patapsco River
• Location selected so ships could off-load raw
  materials and transport finished product
• Produced steel plates, strip steel, sheet steel,
  and tin plate
• Plant has downsized since its heyday in the
  1950s when it employed over 30,000 people

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Water Reuse Agreement - History

• Bethlehem Steel needed larger supply of water
  than available from ordinary sources
• Original Agreement executed in 1941
• Bethlehem Steel constructed 4.5 mile 60 pipeline
  to convey water
• Max rate of 50 MGD
• 1947 amended to 100 MGD max

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Water Reuse Agreement - History

• 1951 amended to 100 MGD min 200 max
• - built additional 96 pipeline
• - built treatment facilities at Back River to
  further treat effluent
• Mid-1980s abandoned treatment facilities.
• Flow gradually has been reduced over time to the
  current level of 40 45 MGD
• Agreement can be cancelled by either party with a
  two year notification.

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LIFT PUMPS
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High Head Lake
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Effluent Water Uses at BS

• Currently takes 40 MGD of Back River final
  effluent for process water
• Used in various steel production processes
• Cooling and cleaning of hot gas streams
• After use the water is treated at their
  Humphreys Creek Facility prior to discharge into
  the Chesapeake Bay

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2008 Annual Water Reuse Costs Paid to City by
Sparrows Point
Bleach 724,155 Power
190,945 Water 24,500 949,600/
Year Based on 44 MGD 2600/day
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Waste Pickle Liquor Agreement

• 1979 initial agreement Bethlehem Steels waste
  product used for P removal at Back River
• 40,000 gal/day
• City constructed loading, storage and dosing
  facilities at Back River
• Trucking costs were split
• 1982 amended City pays 2/3 trucking and
  Bethlehem Steel 1/3

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Waste Pickle Liquor Agreement

• 1986 amended City pays 100 trucking
• December 2000 changed from ferrous sulfate to
  ferrous chloride
• Ferrous chloride a preferred product due to
  decreased acidy and higher iron content
• Reduced quantity to less than 10,000 gallons/day
• Current average usage is 8,000 gallons/day

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POTABLE WATER CONSEVATION

• Plant has converted pump seal water systems and
  polymer mixing systems from potable water to
  plant flushing water
• Saves over 100,000 gpd of potable water
• Potable water still used as backup source
• Saves over 36.5 million gallons of potable water
  per year
• Annual savings of over 50,000

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Seal Water System
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Poly-Blend System
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ELECTRICAL DISTRIBUTION UPGRADES

• SC- 9555 Electrical Distribution Upgrade
• 4,000,000 capital cost
• Installed four new 34.5 kV capacitor banks to
  maintain power factor between 0.9 and 0.98
• Upgraded the 13.2 and 2.4 kV feeders to 34.5kV
• Standardize entire plant distribution system to
  34.5kV
• SC- 835 Blower House 2 Controls System
  Improvement
• 1,800,000 capital cost
• Replaced across the line starters with soft
  starts
• Replaced blower and guide vane controls
• These projects improved energy efficiency and
  increased system reliability

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ENERGY PERFORMANCE CONTRACTING

• Mechanism to implement necessary infrastructure
  improvements that reduce energy consumption and
  operating costs.
• Financed through operating budget utility
  savings.
• No impact to capital funding program.
• Performance and savings guaranteed.

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ENERGY PERFORMANCE CONTRACTING PROCESS

• Preliminary Feasibility Study
• Share information and identify potential savings
• Phase 1 Agreement
• Lists ECMs and potential savings
• Develops costs for Phase 1 Proposal
• Phase 1 Proposal
• Completes detailed energy audit, project scope,
  savings and final proposal
• Phase 2 Agreement
• Complete design followed by construction
• After construction, measurement and verification
  data collected and reconciled annually

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PROJECT RESULTS

• Project Cost 14.1 Million
• 1.8 Million in Annual Energy and Operational
  savings in first year
• Sustainable and reliable solution
• Funded through savings in operating budget
• Increased equipment redundancy and reliability
• Demonstrates BRWWTPs commitment to energy
  conservation

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ENERGY CONSERVATION MEASURES (ECM)

• ECM 1 - Digester Gas Utilization
• ECM 2 - Digester Recirculation Pump
  Improvements
• ECM 3 - HVAC Improvements
• ECM 4 - Direct Digital Ventilation Controls
• ECM 5 - Lighting Improvements
• ECM 6 - Water Conservation

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ECM 1 DIGESTER GAS UTILIZATION

• Digester Gas Conditioning
• Two new gas conditioning skids for cleaning,
• drying and siloxane removal
• Engine Generators
• Three 1 MW Waukesha Enginators designed for
  landfill and digester gas
• Recovery Steam Generators (HRSGs)
• Capture waste heat from engine exhaust to produce
  low pressure steam

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ECM 1 DIGESTER GAS UTILIZATION

• Plant biogas needs will be met first and all
  excess biogas will be used by generators.
• Generators sized to handle annual average of 1.1
  million cubic feet of gas per day.
• Electricity generated must be used on-site and
  cant be fed back to grid (Interconnect
  Agreement)
• Cogen Facility will be operated and maintained
  by JCI under a Maintenance Agreement

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ECM 1 DIGESTER GAS UTILIZATION

• Financial and Operational Benefits
• Clean gas will be available throughout site.
• Improved reliability of HVAC and process boilers
  due to clean gas.
• Convert wasted flared biogas to electricity.
• Heat recovery/steam generation results in more
  digester gas available to engines.
• Sustainable and reliable solution.
• Produces 20 of Plants electrical requirements

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ECM 2 DIGESTER RECIRCULATION PUMP

• ESD Recirculation Pump Improvement
• Replace one vortex pump in each digester
• Replace with a Hidrostal pump
• Energy consumption reduced by 55 HP

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ECM 3 HVAC IMPROVEMENTS

• 320 ton York absorption chiller boiler unit
• 125 gallon domestic water heater
• Split system heat pump with programmable
  thermostat
• 2 cast iron sectional hot water boilers
• Benefits
• More efficient use of digester gas
• Increased equipment service life
• Reduced maintenance and improved redundancy

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ECM 4 DIRECT DIGITAL CONTROL/VENTILATION
OPTIMIZATION

• Direct Digital Control
• Metasys energy management system (EMS)
• Lab exhaust fan monitoring and control
• Ventilation Optimization
• Establish schedule and ventilation rates for fan
  systems
• Optimize return and outside air ratios
• Electric Unit Heaters
• New non-adjustable fixed range thermostats

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ECM 5 LIGHTING IMPROVEMENTS

• Energy efficient electronic ballast
• Occupancy sensors for low use areas.
• Re-lamping/ re-ballast existing fixtures with 28W
  T8 lamps and magnetic ballasts.
• Replace metal halide high pressure sodium
  fixtures with energy efficient high output T5
  fixtures.
• LED exit signs.

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ECM 6 WATER CONSERVATION

• Installation of the following water conservation
  devices
• Replace 3.5 gpf toilets with 1.6 gpf low flush
  toilets and flush valves
• Replace 4 gpm shower heads with 2.5 gpm reduced
  flow shower heads
• 0.5 gpm aerators on restroom sinks
• Water less urinals in Administration Bld.

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SUMMARY OF ANNUAL SAVINGS (Year 1)

• ECM 1 Digester Gas Utilization 1,630,000
• ECM 2 ESD Recirculation Pump 15,145
• ECM 3 HVAC Improvements 32,250
• ECM 4 Digital HVAC Control
  46,500
• ECM 5 Lighting Improvements
  81,350
• ECM 6 Water Conservation 1,050
• TOTAL 1,806,000

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BGEs RIDER 24 LOADRESPONSE PROGRAM

• Customers that can reduce electric loads during
  peak demands receive credits on bill for
  enrolling
• Credits based on amount of load reduction
• 1,000 kw load reduction worth 70,000/yr
• Customers can participate by either shutting down
  equipment or running generators
• Maximum load response is 10 times per year for up
  to 6 hours. (Monday-Friday)
• Average number of activations over past 6 years
  was1.6 requests per year

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WWFD ENROLLMENT

• Location Capacity (kw) Annual Credit ()
• Back River 2,000 144,682
• Patapsco 1,366 98,329
• Eastern Ave PS 433 31,869
• Jones Falls PS 250 18,400
• Dundalk PS 115 8,454
• TOTAL SAVINGS 301,734

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ONSITE BLEACH GENERATION

• Construction of bleach/chlorine gas generation
  facility of maximum 15,000 /day equivalent
  chlorine.
• Hybrid system which produces chlorine gas for
  immediate use, 12 bleach and excess caustic
  soda.
• Estimated project cost 18.5 million
• Excess caustic use in scrubbers and future ENR
• Project payback less than 6 years
• Estimated production cost for chlorine 0.40
  vs. bulk delivery cost of 0.97.

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FUTURE ENERGY CONSIDERATIONS

• Solar Power
• Hydrogen Gas Utilization from OSBG
• Digestion Process Enhancements
• Possible 4th Enginator
• Biodiesel production from scum and grease

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QUESTIONS?
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