uv_filtration decision ppt final (5) 09-08-06

8/14/2019 UV_Filtration Decision PPT FINAL (5) 09-08-06

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Water TreatmentDecision

Stakeholders Panel

August 6, 2009


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Stakeholders Panel

Your role Understand Tacoma Waters treatment decision

Why we must act

Options

Benefits & risks

Impacts

Help shape communication messages Provide feedback to the Public Utility Board


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Why Additional Treatment?

Tacom as G re en Ri ver wat er sup ply i sunfiltered Failing to me et an y o f 1 2 leg al requirem ents

(crit er ia t o remain unf il tered) trig gers f iltratio nFed er al la w r equi re s: Treatment o f Cryptosporidium in unf il teredsur face w at er sup pli es t o:

Reduce incidents of cryptosporidiosis agastrointestinal illness caused by ingestion ofCryptosporidium

Reduce exposure to other pathogens like Giardia thatcan co-occur with Cryptosporidium


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Green River Treatment Plant Location


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Treatment Option 1 UV Light

How ul tr avio let li gh t works

Ultraviolet (UV) light treatment exposesdisease-causing organisms to high levels ofphoton energy at particular wavelengthssterilizing organisms reproductive DNA,making them unable to replicate and cause

disease in humans.


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Utility Impacts - UV Treatment

Benefits Regulatory compliance

Lowest initial capital &

operational costs If clearwells are constructed,

associated water storagewould improve reliability &

emergency response

Ri sks Filtration might be required

later

Can create significantoperational challenges

Future water supply mayhave increased organic

material with higherdisinfection byproducts UV will not be beneficial.

Provides no response tochanging water quality


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How UV Light Impacts You

Cost Approximately

$70 million

(-30% /+50%)

System-wide rate

increase between

5-10%

Ri sks No reduction in

disinfection byproducts

No benefits for taste,

smell, or appearance

Filtration may be

required later causing

even higher rates

Yellow water willcontinue to seasonallyoccur, be visible to youand impact privatefiltration systems.

Benefits Protects public

health through

additional

disinfection

Legal

compliance


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Treatment Option 2 - Filtration

How fi ltr ati on works Adding specific chemicals to the water supply

causes particles and harmful organisms likeCryptosporidium to stick together into largerparticles that are captured in a six-foot filter of sandand sand-like material. After filtering chemicals,contaminants and sediments, we would disinfect,

then serve clean water to you.


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Utility Impacts - Filtration

Benefits Legal compliance

Broad protection ofpublic health

Positions utility to meetfuture regulations

Handle a wider-range ofwater quality issues

Increase reliable supplyfrom the Green Rive

Ability to respond toproblematic water quality

Ri sks Rate increase to customers

Waste removal = more $

Some operationalcomplexity

Increases competition for$ among other watersystem needs


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How Filtration Impacts YouCo sts Approx. $140

million(-30%/+50%)

System-widerate increaseapprox. 15-20%

Ri sks Higher impact

on rates thanUV

Benefits Broad public health

protection

Reduces sand/silt insystem & cost forflushing

Reduces yellow water

Increases available

water during fall &early winter

Legal compliance


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Schedule

2008 2009 2010 2011 2012 2013 2014 2015

Conclusion ofCryptosporidium

Advertiseconsulting

services RFP for

Installation deadlinew/2-year extension

Public

Public Utility Board& RWSS Partner

Anticipatedoperation ofFish Passage

Environmentalreview, WaterTreatment Plant

WaterTreatment

Treatmentplant

RWSS Partners = CovingtonWater District, City of Kent &

CityCouncilbudget &


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Schedule2008

Conclusion of Cryptomonitoring

2009

Water treatment pilot testingbegins

Hire consultant to help examineoptions

Public outreach/education

2010

Public Utility Board & RWSSPartner decision

City Council budget & ratesapproval

Water treatment pilot testing

ends

Treatment plant design &

permitting begins

2011

Environmental review begins

2012 Treatment plant design &

permitting ends

2013

Construction begins

2014 Environmental review ends

Installation deadline w/2yr ext.

2015

Anticipated operation of FishPassage at Howard Hanson


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Summary

Tacoma Water must build additional treatmentfacilities to meet new federal requirements. The

Public Utility Board will decide betweenfiltration and ultraviolet light treatment. Either

option will significantly impact rates.

The Stakeholder panel plays a key role inproviding feedback to help the Utility Board

make its decision.


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Whats Next?

Next Stakeholders Panel Meeting

Monday, August 31, 2009

11:30 a.m. to 1 p .m.

Agenda

Public Outreach Plan

Messaging/sample print collateral

uv_filtration decision ppt final (5) 09-08-06

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