Assessing Plant DBP PerformanceUsing the DBP-CPE

Warren J. Swanson, P.E.Warren J. Swanson, P.E.

2004 RMSAWWA/RMWEA Annual ConferenceGrand Junction, Colorado

Schmueser gordon meyer, inc. Glenwood Springs Aspen Crested Butte

Meeker

Thanks to the Project Team…

Alison Dugan, USEPA, CincinnatiAlison Dugan, USEPA, Cincinnati Total System Optimization programTotal System Optimization program

Larry DeMers, Process Applications, Inc., Fort Larry DeMers, Process Applications, Inc., Fort CollinsCollins

R. Scott Summers, CU BoulderR. Scott Summers, CU Boulder

This Presentation Will…

Increase awareness of EPA’s optimization Increase awareness of EPA’s optimization effortsefforts

Introduce DBP optimization Introduce DBP optimization toolstools being being developed for states and utilitiesdeveloped for states and utilities

Hopefully, encourage participation!Hopefully, encourage participation!

Why Optimize?

Why Not?

Improve Water Quality in Your

Community!

Increase Operations Efficiency!

BoostWorkplace

Satisfaction!

EnsureRegulatory

Compliance!

What is a CPE?

CComprehensiveomprehensive TechnicalTechnical, managerial, financial, managerial, financial

PPerformanceerformance Measured against goals that Measured against goals that EXCEEDEXCEED regs regs Roots in optimized filter performanceRoots in optimized filter performance

EEvaluationvaluation What limits a systems performance?What limits a systems performance? What control strategies apply?What control strategies apply? Can Can optimizationoptimization alone achieve goals? alone achieve goals?

CPE Contexts and Uses

1) 1) Stand-alone evaluationStand-alone evaluation By a water utility or its consultantBy a water utility or its consultant By a State primacy agencyBy a State primacy agency

2) 2) Part of a larger programPart of a larger program EPA-State area-wide optimization EPA-State area-wide optimization

programsprograms

What is a DBP-CPE? Extension of traditional CPEExtension of traditional CPE Focus: Focus: Simultaneous OptimizationSimultaneous Optimization of of

DisinfectionDisinfection Disinfection By-ProductsDisinfection By-Products

By nature, it’s scope is By nature, it’s scope is systemsystem-wide:-wide:

WTP DistributionSystem

RawWater

Quality

Histo rical Data Assessm en t Ad m in ., Desig n , & O p eratio n s Assessm en ts

Determ in e D /DBP Cap ab ility

Exit M eetin g & Rep o rt

Id en tify Perfo rm an ce L im itin g F acto rs

Staff In terview s

Prelim in ary D /DBP Co n tro l S tateg ies

O n -S ite Sp ecial S tu d ies

En tran ce M eetin g & W ater System To u r

Pre-CPE Data Co llectio n & S tu d ies

DBP-CPEComponents

Optimized DBP Goals (currently draft)

TTHMs and HAA5TTHMs and HAA5 Locational Running Annual Locational Running Annual

Average BasisAverage Basis TTHMsTTHMs: : 7575 g/L; g/L; HAA5HAA5: : 5555 g/Lg/L

Total Organic Carbon (TOC) Total Organic Carbon (TOC) RemovalRemoval Exceed Enhanced Coag.Exceed Enhanced Coag.

Requirements by 10%Requirements by 10%

Case Study: City of Winchester, USA

4.5-mgd conventional plant4.5-mgd conventional plant 10,000 customers10,000 customers No Stage 1 DBP Rule compliance issuesNo Stage 1 DBP Rule compliance issues Higher than desired DBPsHigher than desired DBPs Stage 2 compliance not a sure betStage 2 compliance not a sure bet

Process Flow Diagram

RM

FLOC/SED CLEAR

WELLMEDIAFILTERS

Cl2

PACl

Cl2

River Source

River Source

Reservoir Source

KMnO4

KMnO4

10-1000NTU

1.5-4.5ppm TOC

Dist. Sys.

One of the First Steps: Historical Distribution System DBP Data Analysis

0

20

40

60

80

100

120

WTP Eff. Loc. A Loc. B Loc. C Loc. D

HA

A5

(u

g/L

)

Qtr. #1 Qtr. #2 Qtr. #3

Qtr. #4 LRAA Goal

55 ppb:HAA5GOAL

Historical TOC Removal Performance Should be Assessed…

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

Jan-

02

Feb-0

2

Mar

-02

Apr-0

2

May

-02

Jun-

02

Jul-0

2

Aug-0

2

Sep-0

2

Oct-02

Nov-0

2

Dec-0

2

VA

LU

E

Running Annual Average Performance Ratio = 1.15

PerformanceRatio

PR Goal=1.1

Raw TOC(mg/L)

FinishedTOC (mg/L)

Historical CT Data Are Very Useful…

0

5

10

15

20

25

30

35

40

Mar

-02

Apr-02

May

-02

Jun-0

2

Jul-0

2

Aug-02

Sep-0

2

Oct-0

2

Nov-02

Dec-0

2

Jan-0

3

Feb-0

3

Mar

-03

Ina

cti

va

ton

Ra

tio

(M

/R) CT Ratio -

End of Clearwell

CT Ratio - End of Sedimentation

Goal of 1.0

Dis

infe

ctio

n A

chie

ved

/ R

equi

red

@ Plant Effluent

After Pre-Cl2Segment

Special Study: On-Site DBP Profile

0

10

20

30

40

50

60

70

80

90

100

Top of Filter WTP Effluent DistributionSystem

% o

f To

tal

% of DBPs Formed

48%

68%

100%

Pre-Cl2 Segment Plant Effluent Dist. Sys.

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Mar

-02

Apr-02

May

-02

Jun-0

2

Jul-0

2

Aug-02

Sep-0

2

Oct-0

2

Nov-02

Dec-0

2

Jan-0

3

Feb-0

3

Mar

-03

Ch

lori

ne

Co

nc

en

tra

tio

ns

(m

g/L

) Min. Cl2 Residuals in Distribution System

Utility Target: 0.2 mg/L, min.

Historical Cl2 Residual Profiling

Special Study: EC Jar Test

0

5

10

15

20

25

30

35

40

0 10 20 30 40 50 60 70

Coagulant Dose

% T

OC

Rem

ova

l

Hist. WTP Op.

Range

Optim-ized

Range

ConsiderSecondaryImpacts:-> Turb.-> pH-> Sludge

Distribution System Can Be Important Area for DBP Control

TANK ANALYSIS TOOLSTANK ANALYSIS TOOLS• Tank turnover spreadsheetTank turnover spreadsheet

• Reducing Water AgeReducing Water Age

• Tank mixing spreadsheetTank mixing spreadsheet• Reducing Stratification & DBP ExcursionsReducing Stratification & DBP Excursions

BOOSTER CHLORINATIONBOOSTER CHLORINATION• Adds to optimization potentialAdds to optimization potential

Control Strategies Are a Key Outcome of a DBP-CPE

Control Control StrategyStrategy

Optimize Optimize DisinfectionDisinfection

Lower TOCLower TOC Optimize Water Optimize Water Age & MixingAge & Mixing

Basis for Basis for ConsideringConsidering

• High ClHigh Cl22 residuals residuals

• High CTHigh CT• DBP ProfileDBP Profile

• PR < 1PR < 1• EC jar testingEC jar testing

• High turnoverHigh turnover• Poor mixingPoor mixing

Secondary Secondary Impacts Impacts (cautions)(cautions)

• Inadequate CTInadequate CT• Turbidity Turbidity • Fe & Mn; T&OFe & Mn; T&O• Low DS residualsLow DS residuals• BiogrowthBiogrowth

• Sludge handlingSludge handling• Low pH (corrosion)Low pH (corrosion)• Turbidity Turbidity

• Low tank volume & Low tank volume & pressurepressure• Short term water Short term water quality changesquality changes

Flexibility to Flexibility to ImplementImplement

• Sufficient post CT Sufficient post CT • Sufficient DS res.Sufficient DS res.• Alternative oxidantAlternative oxidant• Alternative T&OAlternative T&O

• Sufficient sludge Sufficient sludge handlinghandling• Alternative Alternative coagulantscoagulants• Alkalinity additionAlkalinity addition

• Flexibility to Flexibility to remove tanksremove tanks• Flexibility to Flexibility to exercise tanksexercise tanks

DBP Capability Assessment Provides Key Information to the Utility…

Even with optimization, Even with optimization, can a plant meet the can a plant meet the goals?goals? More challenging question than for a microbial More challenging question than for a microbial

CPECPE

““DBP Capability Assessment Tool” (DBP-CAT)DBP Capability Assessment Tool” (DBP-CAT) Predictive spreadsheet programPredictive spreadsheet program Considers major control strategiesConsiders major control strategies Currently being field-testedCurrently being field-tested

Wrap-up

USEPA currently developing DBP USEPA currently developing DBP optimization tools for States and water utilitiesoptimization tools for States and water utilities

These tools are being developed and field-These tools are being developed and field-tested around the countrytested around the country

Project team seeks interested utilities!Project team seeks interested utilities!

For more information, contact:

warrens@sgm-inc.com

Schmueser gordon meyer, inc. Glenwood Springs Aspen Crested Butte

Meeker