Transcript Slide 1

2010
WATER TREATMENT
DECISION
1
PRESENTATION OBJECTIVES
Update information
•
Decision framework
•
Evaluation criteria for considering options
•
Cost estimates
•
Risk
•
Public outreach & input
Identify
•
Areas of concern about information
2
PRESENTATION OVERVIEW
Problem recap
Project team & approach
Water treatment alternatives analysis & what others are doing
Frame alternative decision criteria – benefits & values
Risks = Consequence x Likelihood
Costs – Initial capital + Operations & Maintenance = Life cycle
Public outreach & response
Next steps & schedule
3
GREEN RIVER TREATMENT DECISION – PROBLEM RECAP
Federal regulations
• New federal law requires treatment for cryptosporidium to further protect public health.
Beyond new law - 12 pre-existing requirements
• “Criteria to remain unfiltered”
Other risks & issues
• Future drinking water regulations
• Non-regulatory water quality challenges
• Cost
Cannot avoid additional water treatment
• Options vs. risks = best long-term value
Recommendation to be made by end of 2009 for April 2014 compliance
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PROJECT TEAM
HDR & CH2MHILL Consultant s
• Water Treatment & Cost Estimating
• Decision Science
Tacoma Water Staff & Executive Management
• Water Treatment & Operations and Maintenance
• Customer relations & project financing
Tacoma Public Utilities – Community & Media Services
• Public Outreach planning & execution
• Communications
Regional Water Supply partners (Lakehaven Utility District, City of
Kent, Covington Water District)
•Water Treatment, Operations & Maintenance
•Regional water supply perspective
5
PROJECT APPROACH
We are here
11/12/09
HDR / CH2MHILL Process chart
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WATER TREATMENT ALTERNATIVES
13 evaluated; four chosen for review (see analysis report on website)
UV light disinfection
1. With storage
2. Without storage – significant discussion on feasibility of operation
Filters
1. Hybrid - Pretreatment (settling of high turbidity) for winter capacity only
2. Conventional – Pretreatment (settling of high turbidity) for full plant capacity
2040 Design capacity
• 90 MGD Winter
Where will these fit?
• 150 MGD Summer
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HOW OTHER MAJOR UTILITIES TREAT (OR PLAN TO)
Public Water System
Seattle
Portland
UV Technology
Filtration
X
X
(Cedar Supply)
(Tolt Supply)
X
(Bull Run)
MWRA (Boston)
X
(Quabbin/Wachusett
Supply)
Vancouver B.C.
San Francisco
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X
X
(Coquitlam Supply)
(Seymour & Capilano
Supplies)
X
X
(Hetch Hetchy Supply)
(Alameda County
Supply)
HOW DO OTHER UTILITIES COMPARE TO TACOMA?
Seattle
The Cedar Supply is nearly entirely (>99%) owned by SPU; the Tolt a blend of SPU and
USFS ownership. Cedar has lower routine turbidity, and SPU has the 15 billion gallon
Lake Youngs reservoir for storage and sustained supply during river turbidity events.
Lk. Youngs can have algae problems.
Portland
The Bull Run Watershed is 100% USFS owned with federal restrictions on use.
Reservoir is maintained relatively full, and elevated turbidity is very rare. Water is
withdrawn directly from reservoir – Portland is making a large investment in intake
reconstruction. Portland can sustain operations in winter with groundwater.
MWRA
(Boston)
Quabbin/Wachusett Supply very high quality with not a single fecal coliform sample
over 20 CFU/mL since 2004, and turbidity almost always < 1 NTU. Water travel time
through the reservoirs measured in years. Periodic algae challenges.
Vancouver
B.C.
Vancouver has three, side-by-side protected watersheds. They have opted to filter two
of them , largely for turbidity control reasons, and have ozone and are installing UV on
the third. Reservoirs are maintained in a generally full condition, and water is
withdrawn directly from the reservoirs. Canada does not have an equivalent regulatory
system.
San
Francisco
Hetch Hetchy Supply comes from Yosemite National Park, and a strongly protected
watershed. Withdrawal is directly from the dam, with very low turbidity (maximum
<0.5 NTU during 2006 – 2008). The Alameda supply is a smaller watershed that
includes developed areas, and is filtered.
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MAJOR DIFFERENCES FOR TACOMA
Green River Diversion
• Ongoing turbidity issues
• Only system to dilute turbidity by blending
Multiple landowners – commercial interests
Federally controlled dam with defined missions
• Flood control – important, but creates unique water quality challenges
• Fish passage (future) – important, but will create water quality
challenges
• River flow augmentation
• Municipal supply (full allocation awaits fish passage)
No clearwell storage – an operational challenge
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TAILOR DECISION TO GREEN RIVER SUPPLY
Simple cost comparison inadequate to evaluate alternatives
Root evaluation in multiple objectives of Water mission
• Protect public health
• Support the economy of the region
• Be appropriate resource stewards
• Make Tacoma a better place to live and work
Aspects of the Mission difficult to monetize
• Values – Identify & characterize how values relate to options & assign
importance for comparison
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FRAMING DECISION CRITERIA – BENEFITS & VALUES
Water Quality &
Public Health
Protection
Cost
Regulatory
Requirements
Developed comprehensive list of values
• All Tacoma and Partners staff and management
participated
Developed criteria to capture breadth of values
• Criteria are exhaustive, measureable and differentiate
between options
Categorized values
• Balanced group representation organized many values
into six categories
Reliability & Yield
Created evaluation model
• Criteria weighted by participants
• Options rated against criteria
Operations
Interactive model will be brought to November 18 meeting
Sustainability
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Very High
PICTURE OF RISK Consequence x Likelihood
Categories
considered
Very Low
3. Non-regulatory
risks could prompt
action
Consequences
2. The regulatory
future – a cloudy
crystal ball
Low
Medium
High
1. The 12 “Criteria to
remain unfiltered” –
filtration triggers
Very Low
13
Low
Likelihood
Medium
High
Very High
PICTURE OF RISK - Criteria to remain unfiltered
Very High
1. Source water Fecal Coliform
limits (6 month running
average)
2. Disinfection Byproducts
(chlorine + natural organics)
below specific levels
High
3. Turbidity Limits
4. Watershed Control
5. Giardia and virus disinfection
Medium
6. Daily certified laboratory
access
7. No waterborne disease
outbreaks
10.Maintenance of chlorine
throughout the system
11.Compliance with Coliform
bacteria requirements
12.Annual inspection of
watershed & treatment
facilities
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Low
Very Low
9. Continuous chlorine into the
system
Consequences
8. Redundant disinfection
equipment
Very Low
Low
Likelihood
Medium
High
Very High
RISKS - continued
Regulatory “Crystal ball”
• We believe with high certainty regulatory complexity will not decrease
• EPA is compelled to publish a “Contaminant Candidate List” every five years &
make regulatory determinations for at least five contaminants.
• Regulatory evolution – Cryptosporidium case study
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RISKS - continued
Non – regulatory water quality risks
• Multiple issues at Howard Hanson Dam
 Fish passage (change in temperature, algae impacts & organics)
 Sediment management (Increasing issue in recent years & likely to continue)
 Structural repairs
• Elevated Iron & manganese (yellow water)
• Railroad operations & expansion
• Fire potential
Non – regulatory, non-water quality risks
• Lost opportunity risk – product acceptance
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COST ESTIMATES
Refine initial 2008 estimates
• Critical objectives
 Establish one set of capital & long-term operating costs
 Consider life-cycle costs
 Clearly define assumptions
• Use CH2MHILL cost estimation model – initial estimates out 9/09
(still -30% / +50% level of estimate)
• Refine cost estimating criteria – finalized 9/09
• Further define issues with narrow & wider uncertainty (10-13-09 workshop)
• Capture best cost estimates for capital, operations & maintenance
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PREVIOUS AND UPDATED COSTS
Treatment
Option
Previous (2008)
Cost Estimate (millions)
Range (-30%/ +50 %)
Best
Estimate
Capital
Conventional
Filtration
Hybrid Filtration
UV with
Clearwells
UV without
Clearwells
O&M
Not
Estimated
Revised
Cost Estimates (millions)
Estimate Range (-15 % / +30%)
Low
Estimate
Capital
Best
Estimate
Capital
High
Estimate
Capital
O&M
$162
$187
$239
$5.1
$140
$6.5
$146
$169
$217
$4.1
$70
$1.0
$68
$80
$105
$1.5
$40
$47
$63
$1.2
Not
Estimated
Areas of change:
UV with Clearwells: Added pump station, site work, electrical facilities , added project delivery
costs.
Hybrid Filtration: Added sitework piping, interconnection with existing facilities, added project
delivery costs.
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ESTIMATED RATE IMPACT OF ALTERNATIVES
Treatment
Option
Average
Existing Bill $/Month
% Increase*
Inside City** Outside City**
Impact to Bill
$/Month*
Inside City
Outside City
Hybrid Filtration
$24.18
$32.36
16% - 20.8%
$3.87 - $5.03
$5.18 – $6.73
UV with Storage
$24.18
$32.36
6% - 7.8%
$1.45 - $1.89
$1.94 - $2.52
*Impact due to treatment alone. These ranges are rate impacts based on the Best Estimate
capital and O&M costs, and the Best Estimate costs plus 30%.
** These are averages across the Residential Class for 2008
Please note that these are estimates based on an assumption that the average system-wide
rate impact will be used for this rate class (residential). Additional analysis is required to
complete the detailed rate impacts across all customers.
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COST AVOIDANCE, SAVINGS & POTENTIAL REVENUE
ECONOMIC ASSUMPTIONS
Assumption
Inputs
Bonding for Entire Project Cost
Best Estimate
Bond Horizon
30 years
Annual Bond Interest Rate
5.0%
Annual Inflation Rate
3.0%
Infrastructure Lifecycle
40 years
Discount Rate
4.5%
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40-YEAR LIFECYCLE COST COMPARISON
PUBLIC OUTREACH
Communication
• Protect & Serve Your Water 2008 – Water Quality Report
• U* customer newsletter articles Summer & Fall 2009
• Dedicated informational Web page: tacomawater.com/decision
• Tacoma Water home page ad
• Bill insert mailed to 180,000 customers September & November 2009
• Water Treatment Decision – CityScape & Cityline, TV Tacoma September 2009
• Power Point presentations to target audiences
• The News Tribune – Kathleen Cooper
• Handout - TNT article, Tacoma Water’s worries
• Water Treatment Decision newsletter (business customers)
•Q&A
• Citizen Stakeholders’ Survey
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PUBLIC OUTREACH
What we’ve heard
Stakeholder Advisory Panel survey
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SCHEDULE
November 4, 2009
Presentation to the Public Utility Board with
information about the public input, risks,
considered benefits & costs for options
December 16, 2009
Presentation to Public Utility Board with
information about public input & a staff
recommendation for treatment
November 12, 2009
Third meeting of the Citizen Advisory Committee
– review risks, benefits & costs for options
January – March, 2010
Follow up with any additional information
requests from the Public Utility Board &
City Council
November 18, 2009
Continued presentation to the Public Utility
Board with information about the alternatives
analysis and interactive work with the decision
model.
Develop additional information on project
delivery alternatives
Finalize project report
November 19, 2009
Presentation to City Council Environment &
Public Works Committee on project approval,
execution, timing & cost of options
Other presentations, including to Pierce County Council
Committee, University Place Council and public, and
interest groups are not all listed.
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FOR MORE INFORMATION
On the Web
Tacoma Water
www.tacomawater.com/decision
EPA – New Surface Water Treatment Rule
www.epa.gov/safewater/disinfection/lt2/
Contact Us
Community and Media Services
Water Conservation
Sonja Hall
Dan Muir
(253) 502-8223
[email protected]
[email protected]
Water Quality
Chris McMeen
(253) 502-8723
(253) 502-8210
[email protected]
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