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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:
Schmueser gordon meyer, inc. Glenwood Springs Aspen Crested Butte
Meeker