Presented by Scott Leland City of Fairfield Water System - - PowerPoint PPT Presentation

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presented by scott leland city of fairfield water system
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Presented by Scott Leland City of Fairfield Water System - - PowerPoint PPT Presentation

Dec 21, 2023 389 likes •536 views

Presented by Scott Leland City of Fairfield Water System Population >109,000 Service connections > 30,000 Two Treatment Facilities: North Bay Regional WTP (40 MGD) Waterman WTP (30 MGD) Waterman Treatment Plant:

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Presented by Scott Leland

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City of Fairfield Water System

  • Population >109,000
  • Service connections > 30,000
  • Two Treatment Facilities:

 North Bay Regional WTP (40 MGD)  Waterman WTP (30 MGD)

  • Waterman Treatment Plant:

 Source water – Lake Berryessa via Putah

South Canal (PSC)

 Largest Single Customer – Anheuser Busch

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Waterman WTP Timeline

  • 1974-76 Original Construction (15 MGD)
  • 1985 Add Two Filters (22.5 MGD)
  • 1991 Add Ozonation (Pre – Ozone)
  • 2006 Operations Building Upgrade
  • 2007-09 Plant Expansion (30 MGD)

 Actiflo, Intermediate Ozone, 4 new filters

  • 2015 Add Carbon Dioxide
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SLIDE 4

Waterman 2007 and 2009

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PSC Water Quality

  • Strong Buffering Capacity
  • Annual Average

2014 2015

 pH (units)

8.48 8.49

 Alkalinity (mg/L)

171 167

 Hardness (mg/L)

179 184

  • Requires excessive Alum dose (40+

mg/L) to treat daily average turbidity

  • f 3 NTU.
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Innovation

  • Challenge - adjust influent pH
  • Motivation - reduce costs
  • Possible Solutions:

 Addition of Sulphuric Acid  Addition of Carbon Dioxide

  • Benefits of Carbon Dioxide

 Lower System Cost  Way Less Hazardous than H2SO4  Plentiful Suppliers  Meets Public Health Standards

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SLIDE 7
  • Tank, Evaporator, Control Panel, In-line Diffuser

2011 CO2 System Components

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  • Carbon Dioxide and Alum

 CO2 dose of 8.1 mg/L reduced pH from 8.5 to 7.4  50% less Alum required for treatment  $74,000 (29%) savings vs traditional operation

  • CO2 and PACL (New Primary Coagulant for WTM )

 CO2 dose of 1.5 mg/L reduced pH from 8.5 to 8.1  PACL dose of 5.8 mg/L required for treatment which

= about 1/3 of typical Alum dose for same conditions

 $162,000 (63%) savings vs. traditional operation

CO2 - Testing, Results, Savings

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2015 CO2 System Components

  • Tank

Evaporator

  • Control Panel

In-line Diffuser

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Barriers/Challenges

  • Plant recently underwent $63 million

upgrade – awkward to ask for another $300,000K

  • Rented metering equipment unreliable
  • CO2 injection affected pumping capacity
  • Tank design issues delayed project

completion by 60 days

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Benefits of CO2 Addition

  • Significant Cost Savings

 Bulk CO2 pricing discount $0.32/lb. vs. $0.0475/lb.  Reduced Alum use/cost  Reduced Caustic use/cost  Less sludge generation

  • Enhanced Operator Tool Box

 Additional primary coagulant choices  Exacting control of influent pH  Optimal TOC removal

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Staff Training

  • Contracted engineering firm designed

testing plan and final bulk tank

  • Initial test system not critical to finished

water quality – (room to experiment)

  • Hands on learning from rented system (3

years)

  • Minimal operator/staff training
  • Boost to Operator confidence
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Lessons Learned

  • What worked:

 Included staff in design and review  Included product supplier in design process

  • What didn’t:

 Communication between owner (City), project

designer, tank manufacturer, and project contractor very inefficient. Delayed project completion by > 60 days.

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Questions…

Thank you!