tm 10: water quality assessment monitoring - detroitmi.gov section discusses the existing water...
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TM 10: Water Quality Assessment & Monitoring Thistechnicalmemorandum(TM)discussestopicsrelatedtowaterquality.Thefollowingtopicsareaddressed:
DWSDwaterqualitygoals
Waterqualitymonitoringplans
Waterqualitymonitoringequipmentandlaboratoryinfrastructure
Customercomplaintshandling
Waterqualitydatahandlinganddocumentation
Waterqualitydatainterpretation
Waterqualityrecommendations
EvaluationofpotentialfordirectfiltrationtreatmentprocessatLakeHuronWaterTreatmentPlant(WTP)
RecommendationsregardingLakeHurondirectfiltration
1.0 Background WaterqualitydatawererequestedfromDWSDandreviewedfortrendsandcurrentcompliance.Datareviewedwere:
MonthlyOperationsReports(MORs)foreachWTPFOR2011,2012andJanuarytoJune2013
TotalcoliformandE.colidataforDWSDandallwholesalesystemsthataremonitoredbyDWSDfor2011and2012
LeadandcopperdataforDWSDandallwholesalesystemsthataremonitoredbyDWSD(mostrecentdatafrom2011)
TOCdatafor2010,2011,2012andJanuarytoJune2013
Mineralanalysesfor2011and2012
TTHMandHAAcompliancedatafor2011and2012
Hexavalentchromiumstudyfrom2011
Partialchemistryfor2012and2013
UCMR1,UCMR2andfirstsetofUMCR3
BromideandBromatedataforWaterWorksParkWTPfor2011and2012
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EDCandPPCPdataforSouthwestWTPfrom2007andfortheintakesatSouthwestandWaterWorksParkfrom2009(WaterResearchFoundationStudy3071PPCPsandEDCs–OccurrenceintheDetroitRiverandTheirRemovalbyOzonation)
Generalplantinformationquestionnairesfrom2013WaterMasterPlanUpdateproject
1.1 Water Quality Goals DWSDestablishedwaterqualitygoalsaspartoftheComprehensiveWaterMasterPlancompletedin2004.ThesegoalsareshowninTable1‐1alongwithrecommendedmodificationsornewgoals.
Table 1‐1: DWSD Water Quality Goals Current and Recommended1
Water Quality Parameter
SDWA Requirement DWSD Goal Comments
All Regulated parameters (VOCs, SOCs, IOCs, radiologicals, SWTRs, D/DBPs and others)
Comply with all applicable primary drinking water regulations
Comply with all applicable primary drinking water regulations
Consider setting higher standards of compliance
Filtered Water Turbidity (ESWTR)
<0.3 NTU in 95% of combined filter effluent samples taken monthly, measurements at 4 hours intervals
<0.1 NTU in 95% of combined filter effluent samples taken each month
Maximum 1 NTU in combined filter effluent
Maximum 1 NTU in combined filter effluent
<0.5 NTU in individual filters after 4 hours of continuous operation (based on 2 consecutive measurements taken 15 minutes apart)
<0.3 NTU in individual filters after 4 hours of continuous operations
<1 NTU in individual filters at any time based on 2 consecutive measurements taken 15 minutes apart
<1 NTU in individual filters at any time
Filtered water particle counts
Not required Minimize particles
Maintain particle counts at baseline level
Microbials (Interim and Long Term SWTR)
3‐log Giardia removal/inactivation
Zero Giardia, virus and Cryptosporidium in finished water
4‐log virus removal/inactivation
2‐log Cryptosporidium removal
1Newandmodifiedrecommendationsareshowninred
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Table 1‐1: DWSD Water Quality Goals Current and Recommended1
Water Quality Parameter
SDWA Requirement DWSD Goal Comments
by filtration
0 to 0.25 log additional Cryptosporidium inactivation based on source water occurrence
Primary disinfection (SWTRs)
≥0.5 log Giardia inactivation (conventional)
≥1.5 inactivation ratio for Giardia inactivation
≥ 1.0‐log Giardia inactivation (direct filtration)
≥3.0 log virusinactivation (direct filtration)
≥2.0 log virus inactivation ≥ 1‐log additional inactivation of Cryptosporidium
Obtaining individual filters effluent of <0.15 NTU 95% of the time per month will provide 0.5 log additional credit. A goal of 1 log drives CIP to ozone and/or UV at all WTPs. Consider it this goal is reasonable.
>1.0 inactivation ratio Ratio is the achieved CT versus the required CT
Total coliform (TCR)
<5% monthly sample positive <5% monthly samples positive
No E. coli positive repeat sample or an E. coli positive routine sample followed by a total coliform positive sample
No E. coli samples positive
Chlorine residual at entry to system (Stage 1 D/DBPR)
<4.0 mg/L <4.0 mg/L
>0.2 mg/L >0.2 mg/L at ends of DWSD distribution system
Chlorine residual within distribution system (SWTR)
Detectable in 95% of monthly samples
>0.1 mg/L in 100% of monthly samples
Chlorine residual at entry points to wholesale customers
>0.5 mg/L
Disinfection Byproducts (Stage 1 & Stage 2 D/DBPR)
TTHM ≤ 80 ppb TTHM ≤40 ppb
HAA5 ≤60 ppb HAA5 ≤30 ppb
Bromate ≤10 ppb Bromate ≤10 ppb
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Table 1‐1: DWSD Water Quality Goals Current and Recommended1
Water Quality Parameter
SDWA Requirement DWSD Goal Comments
Disinfection Byproducts at entry to wholesale customer systems
TTHM ≤40 ppb
HAA5 ≤30 ppb
TOC (Stage 1 D/DBPR)
<2.0 in source water to avoid enhanced coagulation
<2.0 mg/L
Color (NSDWR) <15 true color units <5 true color units Color is not currently measured
Taste and Odor (NSDWR)
<3 TON <1 TON
No objectionable odor in finished water and in distribution system
Lead (LCR) <0.0015 mg/L in 90th percentile <0.0015 mg/L in 90th percentile
Copper (LCR) <1.3 mg/L in 90th percentile <1.3 mg/L in 90th
percentile
Orthophosphate (None)
None, but must meet lead action levels at the tap
>1 mg/L as PO4 Established by MDEQ per LCR. Consider future impact on wastewater discharge quality
pH (NSDWR) 6.5 to 8.5 7.0 to 7.9 Recommend tighter control of pH, assess distribution system corrosion
Aluminum (NSDWR)
0.05 to 0.2 mg/L <0.2 mg/L in finished water
Iron (NSDWR) <0.3 mg/L <0.1 mg/L in finished water and in distribution system
Theoriginalsetofgoalsdidnotaddressspecificwaterqualityassociatedwithsomeregulations,suchastheVOC,SOCs,IOCs,radiologicals,corrosivity,andothersecondaryregulatedparameterslikeiron.ItisassumedthatDWSD’swaterqualitygoalsaretomaintain“regulatorycompliance”unlessotherwisespecifiedinTable1‐1.Inaddition,therewerenogoalsforthedistributionsystemsuchaswaterage,tankturnoverandotheroperational/waterqualitypotentialdistributionissues.Thereforethistablewasupdatedandexpandedtoincludecomprehensiveregulatorycomplianceaswellassomegoalsthatgobeyondbasiccompliance.
DWSDparticipatedinthePartnershipforSafeWaterandthewaterplantswereaccredited.Participationwasdiscontinuedin2012forunknownreasons.SomeplantsstillpreparedthePartnershipdata.AsofJanuary2014,participationinthePartnershipforSafeWaterhasbeenre‐established.Itmaybebeneficialtoconsiderparticipationinotherbenchmarkingprogramssuchas
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QualserveandDistributionSystemOptimizationProgram.However,AWWAisnolongerfundingtheQualserveprogramandtheonlyactivityoccurringisdatacollection.Nonethelesstheremaybevalueinassessingandfollowingthebestpracticesdevelopedunderthisprogram.
2.0 Current Monitoring Plans Thissectiondiscussestheexistingwaterqualitymonitoring,waterqualitydata,andthestafforganizationinvolvedinwaterqualityassessment.Itconcludeswithrecommendationsforfuturewaterqualitytesting.
2.1 Water Quality Monitoring DWSDtestssourcewaters,finishedwatersandthedistributionsystemforawidevarietyofparameters(Table2‐1).Inaddition,specialstudiesareconductedthroughWaterResearchFoundationparticipation,consultants,theDWSDWaterQualityGroupandregulatoryrequirementssuchastheUnregulatedContaminantMonitoringRule.
InadditiontotestingDWSDsourceandfinishedwaters,DWSDteststheCityofDetroitdistributionsystem.DWSDcollectsandanalyzessamplesforretailcustomers.DWSDalsoprovidestotalcoliformsamplecollectionandtestingfor84ofthe127communities.TotalcoliformandE.coliareanalyzed.Dependingonthetypeofcomplaint,metalsanalysisissometimesperformed.Costsforthisarereportedlybuiltintothecustomerrate.DWSDprovidesanalyticalservicesforleadandcopperfor91communitiesbutthesamplingresponsibilityresideswiththecommunity.Nootheranalyticalworkisprovidedtothecommunities.DWSDcouldpotentiallyofferadditionalwaterqualityservicestotheircommunitiesanddevelopanappropriatepricingstructure.
AcompletedescriptionofthewaterqualitymonitoringprogramisshowninTable2‐1.Thistablealsoincludesrecommendationsforthefutureprogram.
TheMDEQrequiredmonitoringscheduleisattachedinAppendixA.
InJanuary2014DWSDbeganfinishwatermineralsamplingatNortheastandSpringwells.CurrentlyonlytheplanttapsatWaterWorksPark,LakeHuronandSouthwestaremonitoredforsomeofthebasicmineralparameters.Sincewatertreatmentprocessesvary,anongoingassessmentoffinishedwaterqualityshouldbemonitoredonallfinishedwaters.
Additionalrecommendationsforthefuturemonitoringinclude:
AssessthevalueofplanktonmonitoringintheplantinfluentsforNortheastandSpringwells.TheseplantssharethesamesourcewaterasWaterWorksPark,butthewaterischlorinatedandthentransportedtotheWTPs,thusprobablydestroyingmuchofthealgaepriortotreatment.Itisimportanttonotethatdestructionofcyanobacteriacanreleasemicrocystinandthatthiswillnotbeassessedusinganalgalcountonachlorinatedsource.
Considerassessingtotalchlorineonsomefrequencytocheckforpotentialreactionswithammonia(monthlyorwhenammoniadetected,inallfinishedwater).
Cyanidetestingisscheduledfor2014.DWSDwillplanforthissamplecollectionandanalysis.
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Table 2‐1: Current Water Quality Monitoring Program and Recommendations for Future
Current Practice Recommended Practice
Parameter Source2 Finished3 Distribution Special Study Source Finished4 Distribution Special Study Comments
Frequency Frequency
Aluminum MO
FI, DR, LHI
MO
All plants Yes at SP
MO
All sources
MO
All plants
At other plants if needed
Aluminum precipitation issues and dosing control
Ammonia MO
FI, DR, LHI
MO
All plants
MO
All sources
MO
All plants
Bi‐Carbonate Alkalinity MO
FI, DR, LHI
MO
All plants
MO
All sources
MO
All plants
Calcium MO
FI, DR, LHI
MO
All plants
MO
All sources
MO
All plants
Carbonate Alkalinity MO
FI, DR, LHI
MO
All plants
MO
All sources
MO
All plants
Chloride MO
FI, DR, LHI
MO
All plants
MO
All sources
MO
All plants
Chlorine (total) Per TCR Online or grab
All plants
MDEQ requires only free chlorine, not total
Good idea to check total on some frequency
Chlorine (free) DA all plants at multiple treatment points
Online
All plants
DA or online at all plants at multiple treatment points
Online
All plants
Per RTCR
Online at storage
Samples also at pre‐CL2, post CL2, applied, filtered, tap
COD MO
FI, DR, LHI
MO
All plants
MO
FI, DR, LHI
MO
All plants
Conductivity MO
FI, DR, LHI
MO
All plants
MO
All sources
MO
All plants
Copper MO
FI, DR, LHI
MO
All plants
50/3 yr
Per LCR
MO
All sources
MO
All plants
50/3 yr
Per LCR Reduced monitoring – consecutive system
Cyanide With phase V Study in distribution system if detected in finished water
Waiver is being rescinded by MDEQ
Dissolved Oxygen MO FI, DR, LHI
MO
All plants
MO
All sources
MO
All plants
Study in distribution system
Fluoride MO & DA
FI, DR, LHI
MO All plants
DA all plants Weekly
DA
All sources
DA
All plants Weekly
MDEQ recommends some routine testing in distribution system
Free CO2 MO
FI, DR, LHI
MO
All plants
MO
FI, DR, LHI
MO
All plants
Iron MO
FI, DR, LHI
MO
All plants
MO
All sources
MO
All plants
Magnesium MO
FI, DR, LHI
MO
All plants
MO
All sources
MO
All plants
2Fi–FightingIsland,DR=DetroitRiveratBelleIsle,LHI–LakeHuronIntake3MostparametersmeasuredatWWP(WaterWorksPark),LH(LakeHuron)andSW(Southwest)only,notatSP(Springwells)orNE(northeast),whendoneonamonthlyfrequency4Recommendationsareforallplantsinservice
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Table 2‐1: Current Water Quality Monitoring Program and Recommendations for Future
Current Practice Recommended Practice
Parameter Source2 Finished3 Distribution Special Study Source Finished4 Distribution Special Study Comments
Frequency Frequency
Manganese MO
FI, DR, LHI
MO
All plants
MO
All sources
MO
All plants
Nitrate MO
FI, DR, LHI
MO
All plants
MO
All sources
MO
All plants
Nitrite MO
FI, DR, LHI
MO
All plants
DMO
All sources
MO
All plants
Non‐Carbonate Hardness MO & DA
FI, DR, LHI
MO All plants
DA all plants
MO
All sources
MO
All plants
Ozone residual DA in contactors
WWP Assume done online
Total Organic Nitrogen MO
FI, DR, LHI
MO
All plants No No Delete this analysis
pH MO FI, DR, LHI
DA all influent
MO All plants
DA SW, LH, SP, NE
2/yr.
LCR
DA
All sources
DA
All plants
10 at 2/yr
LCR
Phosphorus MO
FI, DR, LHI
MO All plants
DA all plants applied & tap
DA at NE in distribution
10 at 2/yr
LCR
MO
All sources
DA
All plants
10 at 2/yr
LCR
Potassium MO
FI, DR, LHI
MO
All plants
YR
All plants
Silica MO
FI, DR, LHI
MO
All plants
YR
All sources
YR
All plants
Sodium MO
FI, DR, LHI
MO
All plants
YR
All sources
YR
All plants
Sulfate MO
FI, DR, LHI
MO
All plants
MO
All sources
MO
All plants
Temperature DA
All sources
DA
All plants
DA
All sources
DA
All plants
Total Alkalinity MO & DA
FI, DR, LHI
MO All plants
DA all plants
DA
All sources
DA
All plants
Total Dissolved Solids MO FI, DR, LHI
MO
All plants
MO
All sources
MO
All plants
Total Hardness MO & MO
FI, DR, LHI
MO All plants
DA all plants
DA
All sources
DA
All plants
Total Solids MO
FI, DR, LHI
MO
All plants No No Delete this analysis
Turbidity See separate table (2‐1a)
UV254 (SUVA calc) MO
All sources
MO
All plants
UV transmittance Study if UV treatment 12 months prior to UV installation
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Table 2‐1: Current Water Quality Monitoring Program and Recommendations for Future
Current Practice Recommended Practice
Parameter Source2 Finished3 Distribution Special Study Source Finished4 Distribution Special Study Comments
Frequency Frequency
planned
Zinc MO
FI, DR, LHI
MO
WWP, SW, LH
MO
All sources
MO
All plants
Bromide MO
WWP
MO
WWP
MO
WWP
Important to monitor is ozone planned at any additional WTPS
Bromate MO
WWP
MO
WWP
Important to monitor is ozone planned at any additional WTPS
VOCs 2 per yr
FI, DR, LHI
Quart
All plants
Online for spill detection
All plants
Quart
All plants Delete VOC on sources
SOCs 2 per 36 mo, done in 2nd and 3rd quarters
All plants
2 per 36 mo, done in 2nd
and 3rd quarters
All plants
Partial Chem YR
All plants
YR
All plants
Radiologicals 9 yrs
All plants
9 yrs
All plants
Metals 9 yrs
All plants
9 yrs
All plants
TOC Quart
All sources
Quart
All plants
MO
All sources
MO
All plants
Fractionation study at WWP
DOC MO
All sources
MO
All plants
TTHM & HAA 2 per yr TTHM
FI, DR, LHI
3 per quart + customers
Quart
All plants 3 per quart + customers
Reduced monitoring for compliance, consecutive system
Delete source water TTHM
WQP (LCR)
10 at 2/yr in Detroit; 70 per year in suburban communities
10 at 2/yr in Detroit; 70 per year in suburban communities
Reduced monitoring
Lead 50 per 3 yr 1 per 3 yrs
All sources
1 per 3 yrs
All plants 50 per 3 yrs Reduced monitoring, consecutive system
Total coliform See separate table (2‐1b)
Chromium hexavalent 2011
All plants
UCMR3
All plants Will monitor in UCMR3
EDCs & PPCPs WaterRF Future
Algae (plankton)
2/wk
FI, DR, LHI
& influent to SP & NE
2/wk
FI, DR, LH All plants, could decrease freq in winter
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Table 2‐1: Current Water Quality Monitoring Program and Recommendations for Future
Current Practice Recommended Practice
Parameter Source2 Finished3 Distribution Special Study Source Finished4 Distribution Special Study Comments
Frequency Frequency
Asbestos Waived
Chlorophyll WK in summer
All sources
Color DA
All sources
DA
All plants
Cryptosporidium LT2 Round 1
All sources
LT2 round 2
All sources Future routine monitoring
Giardia ICR Repeat at some frequency (3 years?)
HPC DA FI, DR, LHI
DA
WWP, SP, LH
Low Cl2<0.1 ppm
DA
All sources
DA
all plants With TCR samples
MTBE 2 per yr
FI, DR, LHI
Quart
All plants All ND Monitor if regulated
Nitrosamines All ND Monitor if regulated
Perchlorate All ND Monitor if regulated
Strontium With UCMR3
Radon Rule has been withdrawn
Odor DA
FI, DR, LHI
DA
SP, LH, SW As needed
DA
All sources
DA
All plants As needed Water Works Park discontinued
ATP Evaluate for security/contamination events/regrowth
Microtox DA
DR
DA
WWP
DA
1 per system Evaluate alternatives
Use TCR sites
Used to do on chemical deliveries
WWP uses
Deltatox DA
FI, LHI
DA
NE, SW
DA
1 per system Evaluate alternatives
WWP = Water Works Park WTP
NE = Northeast WTP
SW = Southwest WTP
SP = Springwells WTP
LH = Lake Huron WTP
FI – Fighting Island intake for Southwest plan
LHI = Lake Huron Intake
DR = Detroit River or Belle Isle intake for Water Works Park, Springwells & Northeast plants
DA=daily
MO=monthly
YR=yearly
Note: For Water Quality Parameters (WQP) (Lead & Copper Rule ‐ LCR) SOCWA, Flint and Genesee County do their own monitoring
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Table 2‐1a: Turbidity Measurements Reported in Monthly Operation Reports from DWSD Treatment Plants
Sample Location Lake Huron WTP Northeast WTP Springwells WTP Water Works Park WTP Southwest WTP Regulatory Requirements Master Plan Recommendations
Raw water 8 hrs 2 hrs hourly 4 hrs hourly Recommended Online
All plants
Settled water none none None 15 min none Recommended Daily
All plants
Applied (filter influent) Daily 30 min hourly Not reported hourly Set consistent frequency for all plants, online
Individual filters 10 min hourly Not reported Not reported Nor reported 15 min 15 min report, online
All filters all plants
Filter confluence 4 hrs 4 hrs Not reported 4 hrs Not reported 4 hrs 4 hrs report, online
All plants
Plant tap Daily Not reported Not reported Not reported Not reported recommended Daily report, online
All plants
Table 2‐1b: Total Coliform Sampling Performed by DWSD Treatment Plants and Associated Water Sources and Distribution Systems*
Sample Location Lake Huron WTP Northeast WTP Springwells WTP Water Works Park WTP Southwest WTP Regulatory Requirements Master Plan Recommendations
Raw water 8 hrs none none Daily Daily Daily Daily
All plants
Plant tap 8 hrs 2 hrs 2 hrs 8 hrs 4 hrs Per MDEQ Per MDEQ
Distribution System 56 per month + customers Consecutive system per MDEQ
56 per month + customers
* Total coliform and E. coli are run simultaneously
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TotalOrganicNitrogenisseldomusedindrinkingwaterandistypicallylowornot‐detectable.Thisanalysiscouldbeeliminated.
Totalsolidsanalysiscouldbeeliminated.
VOCanalysisonsourcewatersshouldbelimitedtospillsassessment.Routinetesting(quarterly)isessentialtomaintaininglabcertificationandanalyticalcapabilityduringaspillevent.
Frequencyofalgaemonitoringcouldbedecreasedinthewinter(asneeded).Samplesareusuallyreportedaszeroandthereforetheanalysisprovideslimitedbenefit.
Odoranalysisisrecommendedonallfinishedwatersdaily.
Colorshouldbetrackedforrawandfinishedwater,especiallyfortheLakeHuronWTPifdirectfiltrationistobeconsidered.
2.1.1 Online analyzers
DWSDusesavarietyofonlinewaterqualityanalyzersforprocesscontrolandregulatorycompliance.Theseonlinemonitorsandtheirplantlocationswerereportedas:
Turbidity(allWTPs)
Freechlorine(allWTPs,noteNortheastneedsforfilters,combinedfiltereffluent(CFE)andsettledwater,Springwellsneedsonrawandsettledwaters)
Particlecounters(SpringwellsandWaterWorksParkhaveonindividualfilters;Springwells,WaterWorksParkandSouthwesthaveonraw,settledandCFE;Northeasthasintheirbudgetforraw,settledandCFE)
Phosphate(WaterWorksPark,Southwest,Northeast)
Fluoride(WaterWorksPark)
Streamingcurrent(Southwest,WaterWorksPark,Northeast)
UV254(WaterWorksPark–justpurchased,notyetinuse)
Theonlineanalyzersrecommendationswillbedevelopedfurtherinphase2ofthisproject.TM‐13WaterTreatmentPlantNeedsAssessmentprovidesestimatedcostsfortheonlinechlorineanalyzersatNortheastandthereplacementofturbidimetersandparticlecountersatWaterWorksPark.
OnlinewaterqualitymonitoringontheDetroitRiverandLakeSt.ClairisdiscussedinTM‐8WatershedManagementandProtection.
2.1.2 Water Quality Monitoring Equipment
TheWaterMasterPlanNeedsAssessmentSiteSurvey(seeTM‐13WaterTreatmentPlantNeedsAssessmentAppendices)includedaquestiononthetypesoflaboratoryequipmentpresentateachwaterplantandatthewaterqualitygrouplab.TheresultsofthatsurveyareshowninTable2‐2.Thistableincudesonlybenchequipmentandnotonlineinstrumentation.Itisexpectedthatadditionalequipmentexistsatdifferentlocationsbutwasnotreportedinthesurveyasthequestionwasopenendedratherthanlistbased.
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Mostrespondentsdidnotincludelaboratoryequipmentreplacementneeds.Laboratoryequipmentisusuallypurchasedundertheoperationsandmaintenancebudget.Thereforeitwasnotassessedforthemasterplancapitalprojects.However,itisimportanttoplanforreplacementaslabequipmentlifetimeistypicallyinthe5to20yearrange.Inaddition,itwassuggestedthatinvestingindedicateddistributionsystemsamplingstationsmaybevaluable.Thedifficultyinestablishingsatisfactorymanualsamplepointsinthedistributionsystemisanongoingchallengeformanyutilities.Asanalternative,samplingstationsmaybeinstalledinthedistributionsystem.However,suchinstallationshouldnotproceeduntilanychangestothedistributionsystemthatcouldimpactwateragehavebeencompleted.Thesesamplingstationscanalsobeachallengetooperateandmaintainduringwinterandthereforearerecommendedwhereacceptableindoorsitescannotbeidentified.
Table 2‐2: Laboratory Equipment Reported in Survey
Equipment Water Works Park
Lake Huron
Southwest Springwells Northeast Water Quality Group
Atomic adsorption spectrometer
x
Autoclave x x x
Balance X x x x x
Conductivity meter x x X x x
Digestion unit x
Dissolved oxygen meter x
Drying oven x x x
Fluoride (ISE) meter X x X x
Freezer x
Glass still/distillation/DI water
x x x
IDEXX sealer x x x
Incubator X x x X x
Microscope x X
Moisture analyzer X
Muffle furnace x
pH meter X X x X x x
Refrigerator x x x
Spectrophotometer x x X X x x
Titration assembly x X
Turbidimeter X X X X x x
Water bath x x
2.2 Lab infrastructure TheneedforlaboratoryinfrastructureupgradeswasdiscussedinameetingwithWTPstaffonOctober8,2013.Staffrecommendedthefollowing:
LakeHuronlabimprovementsin20yearCIP
NElabimprovementsin5yearCIP
Springwellslabimprovementsin5yearCIP
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WaterWorksParkimprovementsnotneeded
SWpartialupdate(cabinets,hoods)in5yearCIP
Waterqualitylabimprovementsnotneeded
2.3 Customer Complaints Handling Inaddition,DWSDtrackscustomercomplaints.SeeAppendixBfortheDetroitCustomerComplaintform.Theformdocumentscomplaintsofrusty/discolored,odor,taste,cloudy/milky,sick/ill/itchyskin,particle/sandanddirty.Arangeof20differenttasteandodordescriptorsareincluded.Historically,DWSDhasexperiencedmusty–MIBtypeodorsmorethanearthy‐Geosmin.Intheeventofatasteandodoreventateitherthewatertreatmentplantorthedistributionsystem,DWSDwilluseFlavorProfileAnalysis.TheFPApanelwilldeterminethetypeandleveloftasteandodor,andPACfeedatthewaterplantinitiated.DWSDprovidessamplecollectionandanalysisforabasicsuiteofparameters.Analysesprovidedaretotalcoliform,phenolphthaleinalkalinity,totalalkalinity,totalhardness,color,odor,chlorineresidual,fluorideandturbidity.DWSD,similartomostutilities,doesnotchargecustomersforwaterqualitycomplaintinvestigations.EitherDWSDorthecustomermaycollectthesample.Onsiteinvestigationisconductedasneededbywaterqualitypersonnel.
DWSDreceivescustomerinquiriesontopicssuchasrustywater,lead,odor,andothers.DWSDcollectssamplesfortheirretailcustomers.Wholesalecustomerscollectsamplesfortheirretailcustomers.TotalcoliformandE.coliareanalyzed.Dependingonthetypeofcomplaint,metalsanalysisissometimesperformed.Inthepast,odorhasbeenafrequencycomplaintrelatedtoalgalbloomsandzebramussels,butthefrequencyhasdeclinedinrecentyears.Rustywatercomplaintsoccurinareaswithhighwaterageandoldunlinedcastironpipe.Othercomplaintsareinfrequent.Alldataarecapturedinadatabase.Complaintssuchachlorinearetrackedbylocation.
Hydrantflushingistheprimaryapproachemployedtoimprovecustomerconcerns.Onsiteinvestigationandsamplingareconductedwhendeemedappropriate.
2.4 Water Quality Data Handling and Documentation WaterqualitydocumentationconsistsprimarilyofSOPs(StandardOperatingProcedures)andsamplingplans.TheWaterQualityGroupreportedthatSOPsexistedforallanalyses,buttheywerenotreviewedaspartofthisproject.WrittensamplingplanswereprovidedforTCRandDBPrequirements(seeAppendixC).TheTCRandDBPsampleplanswereupdatedinJuly,2013.BothplansfollowtheMDEQtemplate.Sampleplansaredocumented,reviewed,andupdateifrequiredonacontinualbasis.Thedatechangesweremadeshouldbeincorporatedinallplans.OnlytheDBPsamplesiteplanwasreviewedaspartofthisproject.TheWTPandWaterQualitylabsarecertifiedbytheMDEQforavarietyofparameters.
TheWaterQualityGrouphasawebbasedsystemforcapturingdata.Thissystemhasbeeninplacesince1998andthusprovidesanopportunityforhistoricalwaterqualityinvestigations.ThissystemcouldbeusedtosharedatamorewidelysuchaswiththeWTPsandwholesalesystems.DWSDgeneratesanextensiveandcompletesetofwaterqualitydata.Itisrecommendedthatadditionaltimebeallocatedtotrendingandinterpretingthesedata.Investigationofanyissuesidentifiedthroughthisevaluationshouldbeconducted.
2.4.1 LIMS
In2013,DWSDdevelopedashortlistofvendorstoprovideaLIMS(LaboratoryInformationManagementSystem).DWSDdevelopedalistofrequirementsforLIMSperformanceandaprocess
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diagram.Thesedocuments(AppendixD)weresenttoChemWater,PerkinElmerandStarLims.Oneofthesevendors,ChemWare,providedtheirquotation(AppendixD)whichofferedapriceof$572,652inMarch,2013.
GiventhecomplexityoftheDWSDmonitoringperformedatboththewatertreatmentplantsandinthedistributionsystemcommunities,aLIMSisrecommended.GiventhatDWSDhasalreadydevelopedthespecificationandacquiredcostinformation,proceedingtopurchaseaLIMSshouldbepursued.ThemainconsiderationisthatimplementationofaLIMSrequiresstafftimefortrainingandsetup.RegularutilizationofaLIMSrequiresdedicatedstafftimethatwillneedtobeincorporatedintooverallstaffinglevels(0.5to1FTE).
3.0 Data Interpretation WaterqualitydatawerereviewedandassessedtodeterminewhichparameterswereofpotentialinterestandfuturechallengeforDWSDregulatorycomplianceandcustomeraestheticsatisfaction.
3.1 Current Water Quality Assessment RegulatorycomplianceisassessedinTM‐9:DrinkingWaterRegulationsPresentandFuture.Additionalanalysisisincludedhereinaswellasanalysisofsomenon‐regulatedparameters.Specificallythissectionaddresses:
Microbialoccurrence
Distributionsystemchlorineresiduals
DBPs&TOC
pH
Alkalinity
Hardness
Corrosionindices
Planktonandalgae
Aluminum,ironandmanganese
Tasteandodor
3.1.2 Microbial Occurrence
Heterotrophicplatecount(HPC)isacommonmethodusedtoassessdistributionsystembacterialregrowth.DWSDmeasuresHPCdailyonthefinishedwatersfromWaterWorksPark,SouthwestandLakeHuronusingR2Aagarmethod.HPCinthedistributionsystemisreportedtobemeasuredonlywhenthechlorineresidualislessthan0.1mg/L.HPCdatawerenotreviewed.ItisrecommendedthatDWSDdevelopadistributionsystemHPCroutinemonitoringplantotrackregrowth,atleastinareasofhighwaterage.Othermethods,suchasATP,existforassessingregrowthbutthesearemorecomplicatedandtimeintensivebutmaybeconsideredinthefuture.
ReviewoftheCCRdataintandemwithDWSDrecordeddatafortotalcoliformsindicateddiscrepanciesbetweenthedatasets.AreviewofallbacterialanalysisdatagatheredbyDWSDwasconductedfordatessampledinthedistributionsystemfor2011and2012.UponreviewoftheDWSD
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data,Table3‐1,Figure3‐1,andFigure3‐2werecompiledtoshowthepositivetotalcoliformcountsthatwerereportedalongwiththecorrespondingchlorineresidualforthedistributionsystemdataandWTPeffluentdata.NopositiveE.colireadingswerereported.
Table 3‐1: Summary of Positive Total Coliform Counts
Township/City Date Corresponding Chlorine Residual (mg/L)
Positive for E. coli
Bloomfield Twp 6/8/2012
7/23/2011
1.03
0.66
NO
NR1
Dearborn Heights 12/7/2012 0.62 NO
Farmington 8/27/2012 0.75 NO
Garden City 6/20/2012
1/13/2011
0.11
0.60
NO
NR
Lake Orion 6/28/2012 0.71 NO
Oak Park 10/2/2012 0.37 NO
West Bloomfield Twp 4/19/2012 0.93 NO
Brownstown Twp
1/14/2011
8/11/2011
9/28/2011
1.19
1.08
1.11
NR
NR
NR
Dearborn 7/8/2011 0.89 NR
Hamtramck 6/7/2011 0.40 NR
Livonia 12/6/2011 0.73 NR
Pittsfield Twp 11/28/2011 0.25 NR
Riverview 8/29/2011 1.01 NR
Taylor 1/7/2011
1/24/2011
0.93
0.86
NR
NR
Westland 11/9/2011 0.88 NR
Detroit
1/7/2011
6/14/2011
8/16/2011
8/18/2011
0.36
0.80
0.77
0.86
NR
NR
NR
NR
Water Works Park WTP 7/8/2011
3/31/2012
0.99
1.15
NR
NR 1NR: Not Reported
For2011,allpositivetotalcoliformcountswerere‐testedasnegativeindicatingtherewasnoneedforfurtheraction;thesere‐checkdatawerenotprovidedfor2012.
3.1.3 Distribution System Chlorine Residuals
Furtherinvestigationintothepotentialrelationshipbetweenfreechlorineresidualandtotalcoliformoccurrencewasconducted.During2011and2012somecommunitiesreportedverylowannualaveragechlorineresiduals(<0.3mg/L)whicharelistedinTable3‐2.
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Table 3‐2: Summary of Low Average Chlorine Residual Communities
Township/City 2011 Average Free Chlorine
# Positive Total Coliform Samples in 2011
2012 Average Free Chlorine
# Positive Total Coliform Samples in 2012
mg/L #/100 mL mg/L #/100 mL
Flat Rock 0.16 0 0.23 0
Grosse Ile 0.26 0 0.29 0
Grosse Point Shores
0.22 0 0.26 0
Forthedistributionsystemdata,thefreechlorineresidualforalltotalcoliformpositivesampleeventsin2011and2012rangedfrom0.1to1.2mg/L.Figure3‐1showstheaveragefreechlorineresidualversusthenumberofpositivetotalcoliformsamplesforeachcommunity.Figure3‐2showstheindividualsampleresultsforfreechlorineresidualwithpositivetotalcoliformsamplesforcommunitieswheretotalcoliformweredetected.Despitesomepositivecountsthathadchlorineresidualsbelowtheminimumrecommendedresidualof0.20mg/L,ingeneraltherewasminimalcorrelationbetweenchlorineresidualandpositivetotalcoliformcountsasshownfromthedataintheabovetablesandattachedfigures.
Figure3‐1:DistributionSystemTotalColiformPositive,SamplesandAverageChlorineResidual,2011‐2012
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Figure3‐2:RelationshipofIndividualSamplesforChlorineResidualandPositiveTotalColiformResults
3.1.4 DBPs & TOC
CurrentregulatorycomplianceisdiscussedinTM‐9DrinkingWaterRegulationPresentandFuture.AdditionalanalysisisofferedinthisTM.Figure3‐3andFigure3‐4showthelocationalrunningannualaverage(LRAA)forthe1stquarter2012(May,SeptemberandDecemberof2011andFebruaryof2012)forselectlocationswheretheLRAAcouldbecalculatedforTTHMandHAA,respectively.Duetosamplesitechangesimplementedbetween2011and2012,onlyalimitedsetoflocationshadsufficientdataforthiscalculation.LRAAsforTTHMsandHAAsarewellbelowtheregulatorylimitsof80µg/Land60µg/L,respectively.TheLRAAlevelswerecalculatedtopredictfuturecompliancewiththeStage2D/DBPrule.DWSDisexpectedtocomplywiththisnewregulationasDBPsarebelowtheMCLs.
ThespeciationofbothTTHMsandHAAswasassessed(Figures3‐1,3‐2,3‐3and3‐4).TheprincipalTHMspeciesacrossalllocationsischloroform(CCl4)followedbydichlorobromomethane(CHBrCl2)anddibromochloromethane(CHBr2Cl).Noincidencesofbromoform(CBr4)wererecordedin2011or2012.Inboth2011and2012,theHAAspeciationismostlyanevensplitbetweentrichloroaceticacid(Cl3AA)anddichloroaceticacid(Cl2AA).NootherHAAspecieswererecorded.
TheformationofTTHMsandHAAswithinthetreatmentplantsandthedistributionsystemwasexaminedanddemonstratedthatbothlocationscreateDBPs.Ingeneral,TTHMconcentrationsincreasebetweentheeffluentofthewatertreatmentplantandthedistributionsystemlocations.Toillustratethiseffect,thegreatestincreasecanbeseenattheMeijer’sGassamplinglocationinPittsfieldTownshipwhichrecordedaTTHMannualaverageof44.2µg/Land20.7µg/Lfor2011and2012,
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
11/18/2010 2/26/2011 6/6/2011 9/14/2011 12/23/2011 4/1/2012 7/10/2012 10/18/2012 1/26/2013
Free Chlorine Residual (mg/L)
Date
Individual Chlorine Residuals for Positive Total Coliform Readings
Bloomfield Twp Dearborn Heights Farmington Garden City Oak Park
West Bloomfield Twp Brownstown Twp Dearborn Hamtramck Livonia
Pittsfield Twp Riverview Taylor Westland Detroit
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respectively(Figures3‐5and3‐6).ItisimportanttonotethatthevaluesintheseFiguresaretheannualaveragesateachlocationandthatnotalllocationshavefoursamplestakeninagivenyear.PittsfieldTownshipislocatedontheperipheryofDWSDssystemandreceiveswaterfromSpringwellsandSouthwest.TheWTPeffluentaveragesofthetwoWTPsthatprovidewatertothislocationwasapproximately15µg/Lin2011andapproximately12µg/Lin2012.TheincreaseinTTHMlevelsobservedin2011andtoalesserextentin2012islikelyaresultofthelongwateragestotraverseDWSDssystembetweentheeffluentoftheSpringwellsandSouthwestplants.Thisincreaseislikelyexacerbatedifwaterissuppliedonlyfromtheplantwiththelongerwaterage.However,astheLRAAiswellbelowtheMCL,DWSDanditswholesalesystemsarecurrentlyincompliance.ThespatialvariationinHAAlevelscannotbecompletelyascertainedastherearenodataavailablefortheWTPeffluents.However,someofthelocationswhichrecordedhighannualaveragesforTTHMsalsorecordedhighannualaveragesforHAAssuchastheMeijerGassamplinglocationinPittsfieldTownshipindicatingthepotentialforaspatialincreaseinHAAswithinthedistributionsystemattributabletolongerwaterages.Figures3‐7and3‐8showsthecombinedrunningannualaverageforeachHAAspeciesforthedistributionlocations.
Figure3‐3:TTHMLRAAforFirstQuarter2012
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Figure3‐4:HAALRAAforFirstQuarter2012
0
10
20
30
40
50
60
70
80
1765 Telegraph Ave City Airport, Lynch and WoodDepartment of Public Works @31800 Meijer's Gas CVS Drugstore
Haloacetic Acid Concentration (ug/L)
1st Quarter 2012 LRAA ‐ HAAs
Cl3 AA Cl AA Br AA Cl2 AA Br2 AA
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Figure3‐5:YearlyAverageTTHMsatDistributionSystemLocationsin2011
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Figure3‐6:YearlyAverageTTHMsatDistributionSystemLocationsin2012
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Figure3‐7:YearlyAverageHAAsatDistributionSystemLocationsin2011
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Figure3‐8:YearlyAverageHAAsatDistributionSystemLocationsin2012
0
10
20
30
40
50
60
Total H
aloacetic Acid Concentration (ug/L)
2012 Avg ‐ HAAs
Cl3 AA Cl AA Br AA Cl2 AA Br2 AA
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BromideandbromatelevelswereanalyzedfortheWaterWorksParkWTPfor2012.AsWaterWorksParkusesozonethepotentialforbromateformationexistsduetoreactionsbetweentherawwaterbromideandozone.AsshowninFigure3‐9,formationofbromateisbelowtheMCLof10g/L.Formationofbromateappearstobehighlytemperaturedependentasbromatelevelsincreaseduringthewarmerwatersummermonths.DuringcoldwatermonthsbetweenOctoberandApril,non‐detectvalueswererecorded.
Figure3‐9:MonthlyBromideandBromateatWaterWorksParkFinishedWaterin2012
3.1.5 DBP Precursors
TotalorganiccarbonDBPprecursorsarelowinDWSDssourcewater.Figures3‐10and3‐11depictthemonthlyTOCvaluesintherawwaterandtreatedwaterofeachofDWSDsplantsfor2010‐2013.TherawwaterTOCvaluesfortheBelleIsle(servesWaterWorksPark,Springwells,andNortheast)onafour‐yearaveragebasisis1.82mg/L.FortheFightingIslandintake(servesSouthwest),thefour‐yearaverageTOCvaluebetween2010and2013is1.95mg/LandfortheLakeHuronintakethefour‐yearaverageis1.55mg/L.Onafour‐yearaveragebasisthefiveWTPsremoved24%,22%,23%,22%,and11%ofinfluentTOCfortheWaterWorksPark,Springwells,Northeast,Southwest,andLakeHuronWTPs,respectively.TheFightingIslandintakehadTOCgreaterthan2mg/LasamonthlyaverageinFebruarywithamaximumvalueof3.2mg/L.
TheStage1DisinfectantsandDisinfectionBy‐ProductsRule(Stage1Rule)doesnotrequireaTOCremovalintreatmentprocessesifthesourcewaterrunningannualaverageTOCisbelow2.0mg/L.Despitethesingle2013highreadingattheSouthwestWTP,DWSDisnotrequiredtoremoveTOCduringtheirtreatmentprocesses.ContinuedmonitoringofTOCisrecommendedtotrackifTOClevelsinthesourcewaterarechangingovertimeasthiswillsignificantlyimpactthetreatmentrequirements.UndertheStage1Rule25%TOCremovalisrequiredforplantswithrawwaterTOCbetween2.0and4.0mg/Landarawwateralkalinitybetween60and120mg/LasCaCO3,therangeforDWSDssourcewateralkalinity.
0
0.5
1
1.5
2
2.5
0
5
10
15
20
25
30
Bromate ug/L
Bromide ug/L
Bromide and Bromate at WWP 2012
Bromide (ug/L)
Bromate (ug/L)[ND = (< 1 ug/L)]
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Figure3‐10:MonthlyTOCConcentrationsinDWSDSourceWaters,Averageof2010to2013withMaximumandMinimumValues
1.0
1.5
2.0
2.5
3.0
3.5
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
TOC (mg/L as C)
Monthly TOC Readings in Source Waters (2010 ‐ 2013)
Lake Huron Fighting Island Belle Isle
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Figure3‐11:MonthlyTOCConcentrationsinDWSDFinishedWaters,Averageof2010to2013withMaximumandMinimumValues3.1.6 pH
pHdataarecollectedmonthlyonsourceandsomefinishedwatersaspartofthemineralsuiteofanalyses(Figures3‐12and3‐12).AdditionaldataaregenerateddailyateachwatertreatmentplantandreportedintheMonthlyOperationsReport(MOR)totheMDEQ.ThehighpHvalueobservedinthemonthlydatafromApril2011dataatLakeHuronisnotconfirmedbythedailydata.TheMORindicatesapHrangeof8.1to8.2forthatmonth.ThelowpHvalueobservedinthemonthlydatafromAugust2012atBelleIsleisalsonotconfirmedbythedailydata.Perthatdataset,thepHisreportedasrangingfrom8.0to8.5.Therefore,thesevaluesfromeitherthemonthlyordailydataaresuspect.
Inthefinishedwater,onlythreeofthefivewatertreatmentplantsarecurrentlyanalyzedforpHperthemonthlydataset.Themonthlydatarangefrom7.2to8.2.ThisvariabilityisobservedtoalesserextentinthedailydatafromtheMORswherepHismonitoredinthefinishedwater.ImprovingtheconsistencyofthefinishedwaterqualityintermsofpHhasthepotentialtoimprovedistributionsystemcorrosion,chlorinespeciationandresidualstability,DBPformationandotherfactors.FurtherevaluationofpHvariabilityandstabilizationoffinishedwaterqualityisrecommended.
1.0
1.2
1.4
1.6
1.8
2.0
2.2
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
TOC (mg/L as C)
Average Monthly TOC Readings in Finished Waters (2010 ‐ 2013)
Lake Huron Southwest Northeast Springwells Water Works Park
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Figure3‐12:MonthlypHinDWSDSourceWaters
6.50
7.00
7.50
8.00
8.50
9.00
9.50pH
pH for DWSD Source Waters 2011‐2012
Lake Huron Fighting Island Belle Isle
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Figure3‐13:MonthlypHConcentrationsinDWSDFinishedWaters
3.1.7 Alkalinity
Alkalinityismeasuredmonthlyaspartofthesetofmineralanalyzesinboththesourceandsomefinishedwaters(Figures3‐14and3‐15).ItisalsomeasuredaspartoftheLCRwaterqualityparametermonitoring,whenTOCiscollectedandsometimesduringcustomercomplaintinvestigations.Alkalinityinthesourcewatervariesfrom80to100mg/L.SimilartopH,thehighvalueofover120mg/LalkalinityobservedinJanuary,2012isnotconfirmedbythedailydata.Inthefinishedwaters,alkalinityvariesfrom70to105mg/L.ThemineralanalysissetsareonlymonitoredatthreeoftheWTPS.Alkalinityisalsomeasureddailyattheindividualtreatmentplants.
6.50
7.00
7.50
8.00
8.50
9.00
9.50pH
pH for DWSD Finished Waters 2011‐2012
Lake Huron Southwest Water Works Park
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Figure3‐14:MonthlyAlkalinityConcentrationsinDWSDSourceWaters
60
70
80
90
100
110
120
130Alkalinity (m
g/L as CaCO3)
Alkalinity for DWSD Source Waters 2011‐2012
Lake Huron Fighting Island Belle Isle
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Figure3‐15:MonthlyAlkalinityConcentrationsinDWSDFinishedWaters3.1.8 Hardness
Totalhardnessismeasuredmonthlyaspartofthesetofmineralanalyzesinboththesourceandsomefinishedwaters(Figures3‐16and3‐17).Hardness,bothtotalandnon‐carbonate,isalsomeasureddailyattheindividualtreatmentplants.Hardnessinthesourcewatervariesfrom100to120mg/L.SimilartopHandalkalinity,thehighvalueofover130mg/LhardnessobservedinJanuary,2012isnotconfirmedbythedailydata.However,itisnotedthattheseparameterswereallhighinthesamesamplesuggestingthateitherthissamplecapturedauniquesetofwaterqualityorthatthesampleprocedurewascompromised.Inthefinishedwaters,hardnessvariesfrom100to115mg/L.TheSouthwestwatertreatmentplantshowshighexcursionsof130toover160mg/L.Thesehighvaluesdonotreflectthesourcewaterdata.Eitherthereisanadditionalsourceofhardnessbeingcontributedbythetreatmentprocessorthedataaresuspect.
60
65
70
75
80
85
90
95
100
105
110Alkalinity (m
g/L as CaCO3)
Alkalinity for DWSD Finished Waters
Lake Huron Southwest Water Works Park
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Figure3‐16:MonthlyHardnessConcentrationsinDWSDSourceWaters
60
70
80
90
100
110
120
130
140Hardness (m
g/L as CaCO3)
Hardness for DWSD Source Waters 2011‐2012
Lake Huron Fighting Island Belle Isle
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Figure3‐17:MonthlyHardnessConcentrationsinDWSDFinishedWaters3.1.9 Corrosion Indices
LeadandCopperRuledataandcomplianceisdiscussedinTM‐9DrinkingWaterRegulationsPresentandFuture.Detroithashadchallengeswithleadlevelsinthepast.BecausetheexactnatureofthepipingmaterialsinthevariousDWSDcustomercommunitiesisnotknown,acompletepictureoftheoriginsoftheleadreadingsisdifficulttoascertain.However,alimitedassessmentcanbemadebasedonthenatureofthefinishedwaterqualityreceivedbyeachcommunity.Thirty‐ninetotalcommunitiesreportedleaddataotherthanzero.Ofthose39communities15receivedwaterfromSouthwest,6fromSpringwells,7fromNortheast,6fromLakeHuron,2frombothLakeHuronandNortheast,2frombothSpringwellsandSouthwest,and1fromWaterWorksPark,Springwells,andNortheast(Detroit).
AnanalysisofwatercorrosivitywasconductedusingtheWTPs’finishedwaterqualitiesfor2011and2012usingthemonthlymineralanalyzes.AveragedataforbothyearsfortheLakeHuron,Southwest,andWaterWorksParkWTPswascalculated.NomineraldataarereportedfortheNortheastandSpringwellsWTPs.Acommercialsoftwarepackage,WaterPRO,wasutilizedtocalculateseveralindustryacceptedstandardsforanalysisofwatercorrosivity.WaterPROusestotaldissolvedsolids(TDS,mg/L),calcium(mg/L),totalalkalinity(mg/LasCaCO3),pH,watertemperature,chloride(mg/L),sulfate(mg/L),andmagnesium(mg/L)asinputs.WiththeseinputsWaterPROcancalculatethefollowingcorrosionindices:
LangelierSaturationIndex(LSI):Recommendedvaluesbetween0.2and0.3,valuesabovethismaycauseexcessprecipitationofcalciumcarbonateandvaluesbelowarepotentiallycorrosive.
60
80
100
120
140
160
180Hardness (mg/L as CaC
O3)
Hardness for DWSD Finished Waters 2011‐2012
Lake Huron Southwest Water Works Park
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CalciumCarbonatePrecipitationPotential(CCPP):Recommendedvaluesbetween4and10mg/LasCaCO3.Thisparameterindicatesthedegreetowhichcalciumcarbonatewillprecipitate,valuesbelowzerowilltendtodissolvecalciumcarbonateandcanbeconsideredcorrosive,whilevaluesabovezerowilldepositvaryingdegreesofcalciumcarbonatefilm,generallyconsideredtoyieldresistancetocorrosion.
Larson’sRatio:TheLarson’sRatioistheratioofalkalinitytothesumofthechlorideandsulfateconcentrations.TheLarsonRatioisusedwhenassessingthecorrosivenessofwatertoironandpotentiallylead.Dependingonthesource,aLarson’sRatioofabove2.0istargetedasanoptimalrange(Imranetal.,2005).Valuesbelow2.0areconsideredcorrosivewhereasabove2.0thewatersareconsiderednon‐corrosiveintheabsenceofotherparameterswhichmayrenderthewatercorrosive.
Tables3‐3,3‐4and3‐5showtheinputdataenteredintoWaterPROtoassessthecorrosivityoftheDWSDfinishedwater.
Table 3‐3: Summary of Input Data for WaterPRO for Water Works Park WTP
Parameter Units Spring Summer Fall Winter
TDS mg/L 144 157 139 134
Calcium mg/L 28 26 26 26
Total Alkalinity mg/L as CaCO3 82 79 85 87
pH ‐‐ 7.52 7.46 7.45 7.28
Temperature oC 11.5 23.2 17.8 9.5
Chloride mg/L 8.5 9.1 9.1 10.2
Sulfate mg/L 31.2 31.2 31.2 31.2
Magnesium mg/L 8.2 7.7 7.6 8.1
Table 3‐4: Summary of Input Data for WaterPRO for Lake Huron WTP
Parameter Units Spring Summer Fall Winter
TDS mg/L 123 140 123 118
Calcium mg/L 26 27 25 25
Total Alkalinity mg/L as CaCO3 82 84 86 84
pH ‐‐ 7.65 7.64 7.51 7.51
Temperature oC 13.6 22.4 19.9 13.7
Chloride mg/L 6.7 8.8 8.7 8.7
Sulfate mg/L 25.4 21.8 32.6 44.5
Magnesium mg/L 7.6 7.7 7.5 7.6
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Table 3‐5: Summary of Input Data for WaterPRO for Southwest WTP
Parameter Units Spring Summer Fall Winter
TDS mg/L 152 146 136 133
Calcium mg/L 30 26 26 27
Total Alkalinity mg/L as CaCO3 89 85 89 95
pH ‐‐ 7.59 7.66 7.36 7.44
Temperature oC 9.4 22.9 16.4 4.70
Chloride mg/L 9.8 9.8 10.4 11.0
Sulfate mg/L 39.1 26.7 32.8 36.6
Magnesium mg/L 8.7 8.2 7.7 8.2
BasedonthecorrosionindicescalculatedfortheinputdatalistedinTables3‐3,3‐4and3‐5,theoutputresultsinTables3‐6,3‐7and3‐8showthattheeffluentfortheDWSDwaterplantsisintherangeofindicesthatcouldbeconsideredcorrosiveastheyarebelow0.2forLSIandbelow4.0mg/LasCaCO3forCCPP.TheLarson’sRatiofortheLakeHuronWTPisacceptableduringthespringandsummer;theSouthwestWTPalsoshowsacceptableLarson’sRatiovaluesduringthesummer.However,fortherestoftheyearfortheSouthwestandLakeHuronandforallseasonsinvestigatedatWaterWorksPark,theLarson’sRatioisbelowtheoptimumvalueof2.0.Theseresultsareconsistentwithintermittentreportsofrustywaterinthedistributionsystem.Unlinedcastironpipeandareasofhighwateragearethemostpronetorustywater.Inaddition,highwateragecanalterthewaterqualityandthusimpactthecorrosionindices.Distributionsystemwaterqualitywasnotavailabletoperformcorrosionanalysesandtocomparetofinishedwater.Forallplantstheindicesdecreasesubstantiallyundercolderwaterconditions.
DespitethegreaterincidenceofleadreadingsattheSouthwestplantbasedonthe90thpercentiledata,waterfromtheSouthwestWTPisnotmorecorrosivethantheotherWTPfinishedwater,basedonanalysisofthecorrosionindicesalone.Asaresult,theremaynotbecorrelationbetweentheleadlevelsandfinishedwaterqualitywhenonlyanalyzingthosetwoparametersalone.Otherfactorsmayplayagreaterrole.Itisrecommendedthattheuseofphosphateasacorrosioninhibitortocontrolleadisappropriate.
Table 3‐6 Summary of Output Data for WaterPRO for Water Works Park WTP
Parameter Units Reference Value
Spring Summer Fall Winter
pH ‐‐ ‐‐ 7.52 7.46 7.45 7.28
LSI ‐‐ 0.2 – 0.3 ‐0.63 ‐0.58 ‐0.62 ‐0.91
CCPP mg/L as CaCO3
4.0 – 10.0 ‐9.42 ‐8.12 ‐9.93 ‐19.7
Larson’s Ratio
NA > 2.0 1.8 1.7 1.9 1.9
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Table 3‐7: Summary of Output Data for WaterPRO for Lake Huron WTP
Parameter Units Reference Value
Spring Summer Fall Winter
pH ‐‐ ‐‐ 7.65 7.64 7.51 7.51
LSI ‐‐ 0.2 – 0.3 ‐0.49 ‐0.36 ‐0.54 ‐0.64
CCPP mg/L as CaCO3
4.0 – 10.0 ‐6.14 ‐4.46 ‐7.97 ‐9.56
Larson’s Ratio
NA > 2.0 2.3 2.4 1.9 1.4
Table 3‐8: Summary of Output Data for WaterPRO for Southwest WTP
Parameter Units Reference Value
Spring Summer Fall Winter
pH ‐‐ ‐‐ 7.59 7.66 7.36 7.44
LSI ‐‐ 0.2 – 0.3 ‐0.54 ‐0.34 ‐0.71 ‐0.77
CCPP mg/L as CaCO3
4.0 – 10.0 ‐8.34 ‐4.23 ‐13.5 ‐16
Larson’s Ratio
NA > 2.0 1.6 2.0 1.8 1.8
ExaminationofthefiguresinSection3illustratesthevariabilityinsomeofthewaterqualityparametersthatimpactcorrosionindices.AssumingallotherwaterqualityparametersremainthesameanincreaseinhardnessresultsinanincreaseintheLSIandCCPPwithnoeffectontheLarson’sRatio.IncreasingalkalinitycausestheLSItoincrease,theCCPPtodecrease,andtheLarson’sRatiotoincrease.IncreasingpHleadstoanincreaseinboththeLSIandCCPPwithnochangeintheLarson’sRatio.Thefluctuationsobservedthroughouttheyearinthefinishedandrawwatermaythusimpactthecorrosivityofthewater,howeveradditionaldataoncorrosionobservationsisrequiredtoconfirmordisprovethisobservation.
WhilemonthlymineraldatawerenotavailableforSpringwellsandNortheast,thefinishedwaterforthoseplantshasaslightlyloweralkalinitythanWaterWorksPark.Asdiscussedpreviously,foradecreaseinalkalinityandassumingallotherwaterqualityparametersarethesameasWaterWorksPark,theLSIisslightlylowered,howevertheCCPPincreasesslightly.
3.1.10 Plankton and Algae
DWSDhasindicatedtheirconcernwithCyanobacteria(blue‐greenalgae)intherawwateroftheirWTPs,specificallyatFightingIslandintaketotheSouthwestWTP.Planktondata,includingblue‐greenalgaecounts,isanalyzedonatwiceperweekbasisintheWTPs’rawwaters.SincetwooftheseWTPsreceivewaterwithasignificantchlorinecontacttime(NortheastandSpringwells),thoseresultswouldbeexpectedtobelowduetodegradationofthealgalcells.Figure3‐17andFigure3‐18showthemonthlyaverageCyanobacteriaconcentrationsfortheLakeHuron,BelleIsle(WaterWorksPark)andFightingIsland(Southwest).Datarecordedbetween2005and2013wereanalyzed.LakeHurondataarediscussedinSection6.
Cyanobacteriacountsaretypicallylow.AttheFightingIslandintake,cyanobacteriaaverageinsingledigitswithpeakvaluesofupto100/mL.However,verbalreportsfromstaffatSouthwestindicatedthatupto60%ofthetotalalgaeareCyanobacteriaduringthesummermonths.Actinomyceteshas
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alsobeenreportedtobepresentandtocausetasteandodor,butnodatawereavailable.AttheBelleIsleintake,cyanobacteriaarenotusuallyinsevenmonthsoftheyearonaverage.TheyaredetectedinFebruary,March,April,MayandSeptemberwithaveragecountsbelow20permL.Thepeakresultreportedwas300permLinMarch.
ThereisnoEPAprimaryorsecondarystandardforCyanobacteria,howevertominimizetheimpactonwaterqualityCyanobacteriacountsarerecommendedtobebelow1,000counts/mL(Kawamura,2000).Overtheeightyearsofinvestigation,DWSDisconsistentlybelowthisrecommendation.BloomsofthisalgaehavebeenreportedontheCanadiansideoftheDetroitRiverbuthavenotyetreachedtheDWSDintakesaccordingtoDWSD’sdata.Vigilanceinmonitoringthisorganismisrecommended.
DWSDhasalsoreportedlargeclumpsoffilamentousalgaeontheflocculationpaddlesatSpringwellsinthepast.Thesealgaewerebleachedindicatingthattheyhadbeendamagedbythechlorinecontacttime.ThealgaewereidentifiedasCladaphora,SpirogyraandLynbia.
Figure3‐17:MonthlyCyanobacteriaConcentrationsinBelleIsleIntakeWater
0
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2 4 0 0 0 2 0 0 0
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Cyanobacteria # per 1 m
L
Belle Isle Average Cyanobacteria Counts (2010 ‐ 2013)
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Figure3‐18:MonthlyCyanobacteriaConcentrationsinFightingIslandIntakeWater
3.1.11 Aluminum
AluminumisregulatedundertheEPAsecondarystandards(seeTM‐9DrinkingWaterRegulationsPresentandFuture).AluminumismonitoredmonthlyinboththesourcewatersandthefinishedwatersatthreeoftheWTPsaspartofthe“mineral”setofanalyses.AluminumisalsoimportanttoevaluateasDWSDusesalumforcoagulation.ExcessaluminumfromeitherthesourcewaterorcoagulationcancreateprecipitationissuessuchasobservedinthepastatSpringwellsWTP.Thesourcewateraluminumconcentrationsvaryovertimeandcanbesignificant(Figure3‐19).Aluminuminthefinishedwatersislowerbutdoessometimesexceedthesecondarystandardof0.2mg/L(Figure3‐20).
2 5
3 2 3 6
1 2 2
1 4 3
0
20
40
60
80
100
120
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Cyanobacteris # per mL
Fighting Island Average Cyanobacteria Counts (2008‐2009, 2011 ‐ 2013)
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Figure3‐19:MonthlyAluminumConcentrationsinSourceWaters
Figure3‐20:MonthlyaluminumConcentrationsinDWSDFinishedWaters
3.1.12 Iron
Ironsamplesarecollectedmonthlyfromthesourcewatersandthreeofthewatertreatmentplantsaspartofthemineralanalysisset.IronisregulatedundertheEPAsecondarystandards(seeTM‐9DrinkingWaterRegulationsPresentandFuture).Ironisimportantasanaestheticissueascustomerswillnoticediscoloredwateriftheconcentrationisabovetherecommendedlimitof0.2mg/L.InDWSD’ssourcewaters,ironvariesupto1.1mg/L(Figure3‐21).Inthefinishedwaters,ironisoftenbelow0.2mg/LbutdoeshavesomehigherexcursionsatbothLakeHuronandWaterWorksPark(Figure3‐22).
0.000
0.500
1.000
1.500
2.000
Jan
Feb
Mar
Apr
May Jun
Jul
Aug
Sep
Oct
Nov
Dec
Aluminum m
g/L
Monthly Averages 2012
Aluminum in DWSD Raw Water Sources 2012
Lake Huron
Fighting Island
Belle Isle
0.000
0.500
1.000
1.500
2.000
Jan
Feb
Mar
Apr
May Jun
Jul
Aug
Sep
Oct
Nov
Dec
Aluminum m
g/L
Monthly Averages 2012
Aluminum in DWSD Finished Waters 2012
Lake Huron
Southwest
Water Works Park
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Figure3‐21:MonthlyIronConcentrationsinSourceWaters
Figure3‐22:MonthlyIronConcentrationsinDWSDFinishedWaters
3.1.13 Manganese
Manganesesamplesarecollectedmonthlyfromthesourcewatersandthreeofthewatertreatmentplantsaspartofthemineralanalysisset.ManganeseisregulatedundertheEPAsecondarystandards(seeTM‐9DrinkingWaterRegulationsPresentandFuture).Manganeseisimportantasanaestheticissueascustomerswillnoticediscoloredwateriftheconcentrationisabovetherecommendedlimitof0.05mg/L.InDWSD’ssourcewaters,manganesevariesupto0.012mg/L(Figure3‐23).Inthefinishedwaters,manganeseislessthan0.003mg/L(Figure3‐24).ManganesedoesnotappeartobeissueforDWSD’ssourceandfinishedwaters.
0.000
0.200
0.400
0.600
0.800
1.000
1.200
Jan
Feb
Mar
Apr
May Jun
Jul
Aug
Sep
Oct
Nov
Dec
Iron m
g/L
Monthly Averages 2012
Iron in DWSD Raw Water Sources 2012
Lake Huron
Fighting Island
Belle Isle
0.000
0.200
0.400
0.600
0.800
1.000
1.200
Jan
Feb
Mar
Apr
May Jun
Jul
Aug
Sep
Oct
Nov
Dec
Iron m
g/L
Monthly Averages 2012
Iron in DWSD Finished Waters 2012
Lake Huron
Southwest
Water Works Park
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Figure3‐23:MonthlyManganeseConcentrationsinSourceWaters
Figure3‐24:MonthlyManganeseConcentrationsinDWSDFinishedWaters
0.000
0.002
0.004
0.006
0.008
0.010
0.012
0.014
Jan
Feb
Mar
Apr
May Jun
Jul
Aug
Sep
Oct
Nov
Dec
Man
ganese m
g/L
Monthly Averages 2012
Manganese in DWSD Raw Water Sources 2012
Lake Huron
Fighting Island
Belle Isle
0.000
0.002
0.004
0.006
0.008
0.010
0.012
0.014
Jan
Feb
Mar
Apr
May Jun
Jul
Aug
Sep
Oct
Nov
Dec
Man
ganese m
g/L
Monthly Averages 2012
Manganese in DWSD Finished Waters 2012
Lake Huron
Southwest
Water Works Park
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3.1.14 Taste and Odor
In1990,DWSDreceivedover400customercallsoftasteandodorinoneday.Theodorwasdeterminedtoberelatedtotheinvasionofzebramusselsandtheirresultingimpactonalgalpopulations.BothgeosminandMIB(2‐methylisoborneol)weredetectedinthedrinkingwater.TheseodorsaretypicallyassociatedwithActinomycetesandCyanobacteriablooms.Whilethisodorissueresolveditselfafteracoupleofyears,thepotentialforareoccurrenceremainsaconcern.Tasteandodorarenotacurrentissue,butitisrecommendedthatcontinuedassessmentandvigilancebeconducted.
4.0 Staff Organization WaterqualitymonitoringisperformedbythewaterqualitygroupandbystaffateachWTP.TheWaterMasterPlansNeedsAssessmentSurvey(2013)requestedadescriptionofstaffateachfacility.Pertheresultsofthissurvey,thefollowingpositionswereidentifiedasperformingwaterqualityanalysesandtheirapproximatepercentoftimeperformingwaterqualityislisted:
WaterQualityDivisionManagerII(one–100%)
PrincipalAnalyticalChemist(one–100%)
SeniorAnalyticalChemist(one–100%)
Microbiologist(one–100%)
SeniorWaterDistributionSystemInvestigator(one–100%)
WaterSystemInvestigator(two_100%)
AssistantWaterSystemInvestigator(one–100%)
SeniorChemist(fourpereachwaterplant,80%atLakeHuronWTPand65%atotherWTPs)
Thisorganizationcreatesatotalstaffof21.6FTE(fulltimeequivalent)waterqualitypersonnelwhenadjustedforpercentoftimespentonwaterquality.Remainingtimeisspentonplantoperationsandmaintenance.
InastudyconductedbyCDMSmithin2012,acomparisonofpopulationservedversusnumberofwaterqualitystaffwasevaluated.Asignificantcorrelationwasobservedbetweentheseparametersbasedonthesevenutilitiessurveyed(Figure4‐1).Thiscorrelationisbasedonthesizeofthepopulationserved.DWSDservesapproximately3.6millionpeople.DWSDperformsallwaterqualityanalysesfortheWTPsbutonlyforaportionofthedistributionsystem.Therefore,thepopulationwasadjusteddownwardsto80to90percentofthetotalpopulationservedtoallowfortheportionsofthedistributionsystemwhicharemonitoredbythewholesalecommunitiesratherthanDWSD.Usingthiscorrelation,itisestimatedthat30to34FTE’swouldbeanappropriatestaffinglevelforDWSDwaterqualitypersonnel.Thissurveydidnotethattwooftheutilitieswereplanningonastaffincreaseinthenearfuture.ComparingthecurrentFTE’stothepredictedFTE’s,itisobservedthatDWSDstaffmaybelowby8to12FTE’s.
ItisalsorecommendedthatateamofwaterqualitypersonnelformthewaterqualitygroupandallWTPsbeestablishedtofacilitatediscussionandcoordinationofactivities.Wholesalecommunityrepresentativescouldalsobeincludedwhenrelevanttopicsareaddressed.
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Figure4‐1:FTEversusPopulationforSurveyedUtilities
5.0 Recommendations on Water Quality Monitoring and Assessment Thefollowingrecommendationsandprojectsareofferedrelatingtowaterqualitymonitoringandassessment.Theserecommendationsarenotnecessarilyinorderofpriority.CapitalprojectsarelistedinTable5‐1.ItisrecommendedthatDWSD:
Reviewwaterqualitygoalsandupdatetobemorecomprehensiveofregulationsandaesthetics.Considermoreglobalapproachthatincludeswholesalesystemsorwaterqualityatthepointsofentry.
ImplementthemonitoringrecommendationsprovidedinTable2‐1.
Developandimplementaplantoreviewandtrenddataroutinely.Establishandutilizecontrollimitsforkeyparameters.
Documentallsamplingplansandupdateannually
Reviewcurrentsamplingplansperrecommendations.
Completespecialstudieson
o Zebramusselimpactonwaterquality
o Aluminumoccurrenceandminimization
o Occurrenceofmicrocystin
o UV254absorbanceandUVtransmittancepriortoanyUVdisinfectioninstallation
Developacoordinatedteamthatincludesrepresentativesfromeachplantandthewaterqualitygroup.Considerrepresentativesfromwholesalecommunities.
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Developaprogramandcostsforprovidinglabservicestowholesalecustomers.
ConsiderparticipationinQualserveandintheDistributionSystemOptimizationprogramsofferedbyAWWA.
RehabthelabsatSpringwells,NortheastandSouthwest.ThisassumesthatthelabrehabatSpringwellsiscurrentlyinprocess.LongertermimprovementsmayberequiredatLakeHuron.
AcquireandimplementaLIMSorotherelectronicmeansofroutinelycapturingalldataandfacilitatingdatasharingamongDWSDfacilitiesandwholesalecommunities.
Addonlineinstrumentstoplantsasneeded(thiswillbefurtherdevelopedinphase2oftheproject).
Monitormicrocystin,MIBandgeosminwhenalgaeblooms
Re‐evaluatethepotentialforusinginstalleddistributionsystemsamplingstationsatselectlocationsinthedistributionsystem
Table 5‐1: Potential Water Quality Capital Projects
Project Study Cost Capital Cost FTEs Schedule Short or Long Term
Rehab lab at Southwest (partial)
$0 $300,000 Short
Rehab lab at Lake Huron $0 $500,000 Long
Rehab lab at Springwells $0 $400,000 Short
Rehab lab at Northeast $0 $500,000 Short
Install distribution system dedicated sampling stations
$0 $500,000 Long
Implement LIMS $0 $500,000 1 FTE Long
Implement monitoring and study recommendations
$0 $0 1 FTE Short
Add online instrumentation as recommended
$0 TBD phase 2 0.25 FTE Short
6.0 Evaluation of Potential for Direct Filtration at Lake Huron WTP InordertomoreefficientlyoperatetheLakeHuronWTPandcreatepotentialcostsavings,DWSDisinterestedinconvertingthistreatmentplantfrommodifieddirectfiltrationtodirectfiltration.Directfiltrationisdefinedby10‐StatesStandardsandadoptedbytheMDEQas“aseriesofprocesses,includingcoagulationandfiltration,butexcludingsedimentation,resultinginsubstantialparticulateremoval”.TheLakeHuronWTPcurrentlyoperatesasa“modified”directfiltrationfacility.TheWTPfeedsalumcoagulantandacoagulantaidpolymerupstreamofsettlingbasins.However,thesesettlingbasinsdonotprovidesufficientdetentiontimeorroutinesludgeremoval.Filteraidpolymeristhenaddedimmediatelyupstreamofthefiltersasneeded.Whilenotatruedirectfiltrationprocess,
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theWTPdoesnotoperateasatruepre‐treatmentfacilityeither.FurtherdiscussionoftheexistingLakeHurontreatmentprocessisprovidedinTM‐13WaterTreatmentPlantNeedsAssessment.
6.1 Introduction ThismemorandumsummarizesareviewofwaterqualitydatafromtheLakeHuronWTPasafirststepinassessingthefeasibilityofdirectfiltration.Datawhichimpactdirectfiltration,andwhichwerereviewedwherefeasible,include:
Turbidity
Planktoncounts(algae)
Totalorganiccarbon(TOC)
Microbials(Totalcoliform,E.coliandHPC)
Temperature
TotalSolids
Color
Chemicaldosages:alum,coagulantaidpolymer,andfilteraidpolymer
TheseparametersarebasedonMDEQand10‐StatesStandardsrecommendeddata.ColordatawerenotavailableforreviewasDWSDdoesnotmonitorcoloratanyoftheirWTPsorsources.TheabovedatawerecompiledfortheLakeHuronsourcewaterandtheWTPtreatedwatertocomparewithindustrybenchmarksforwaterqualityrequirementsfordirectfiltration.AdditionalwaterqualitydataarepresentedinSection3.
ThismemorandumdoesnotincludeareviewofLakeHuronWTPoperatingparametersforassessmentofdirectfiltrationfeasibility.Thememorandumconcludeswithrecommendationsandnextstepsrequiredtopursuedirectfiltrationfurther.
6.2 Review of Water Quality Data Directfiltrationisgenerallyfeasibleforsourcewaterswithminimalrawwaterturbiditiessuchthattheadditionalsolidsloadingonthefilterswillnotimpactfilteroperations.OtherWTPsusingLakeHuronsourcewatercurrentlyoperateasdirectfiltrationfacilitiessuchastheLakeHuronWTPfortheCityofLondon,Ontario.AtthatWTP,diatomswerereportedasaparameterimpactingthedirectfiltrationprocessesatthatplant(Foley,1981).ThefollowingillustraterelevantdatafortheLakeHuronWTP:
Figure6‐1showsthemaximumdailyturbidityvaluesfortheLakeHuronsourcewateronamonthlybasisfortheperiodof2005and2013.
Figure6‐2showsthedailyturbidityreadingsfortheLakeHuronsourcewateraveragedonamonthlybasisbetween2005and2013
Figure6‐3showsafrequencyplotofallmaximumdailyturbidityreadingsfortheLakeHuronsourcewaterbetween2005and2013.
Figure6‐4presentsallmonthlyTOCdataforLakeHuronsourcewaterandtreatedwaterbetween2010and2013
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Figure6‐5showsafrequencyplotofallmonthlyTOCdatafortheLakeHuronsourcewaterandtreatedwater
Figure6‐6illustratesthemonthlyaverageblue‐greenalgaeanddiatomcountsfortheLakeHuronsourcewaterfortheperiodof2005to2013.Maximumvaluesarealsoshownonthechart.
Figure6‐7presentsafrequencyplotofallblue‐greenalgaecountsanddiatomcountsfortheperiodof2005through2013.
Figure6‐8presentsthetotalcoliformdata
Figure6‐9presentstheHPCdata
Figure6‐10andFigure6‐11showalumandcoagulantaidpolymerdosages,respectively.
TheresultsofFigures6‐1to6‐11plussomeadditionaldataaresummarizedinTable6‐1.
Figure6‐1:MaximumDailyTurbidityValues‐LakeHuronSourceWater2005to2013
8.6
18.0
19.4
15.0
19.5
11.6
17.0
6.4
5.6
20.0
21.8
20.0
5.4
12.0
8.9
3.5
1.9
2.8
1.3
2.1
1.11.5
5.3
3.8
2.9
4.6
2.8
1.81.3
1.6 1.4
0.70.5
2.0
3.1
20.0
14.0
19.4
13.0
3.8
1.7
2.83.1
4.9
9.8
16.0
11.0
5.8 5.9 5.9
12.2
4.5
1.6 1.61.3
1.0 1.1
0.40.9
9.4
13.0
15.0
3.6
2.01.7
1.1 1.1 1.0 1.1
6.6
20.020.0
14.4
19.0
8.2
19.5
11.6
17.0
6.4
5.6
14.0
4.34.7
5.6
7.8
4.4
11
7.4
4
1.11.6
20
21.8
18
6.5
18
19
13.8
8.6
5.4
0
5
10
15
20
25
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Turbidity (NTU
)
Lake Huron WTP Max Daily Turbidity Readings (2005 ‐ 2013)
2005 2006 2007 2008 2009 2010 2011 2012 2013
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Figure6‐2:DailyTurbidityReadingsfortheLakeHuronSourceWater,AveragedonaMonthlyBasisbetween2005and2013
1.451.59 1.53
1.33
0.900.73
0.55 0.51 0.60
1.071.20
1.45
0.35 0.44 0.440.65
0.31 0.23 0.24 0.26 0.30 0.33 0.28 0.310.06 0.06 0.05 0.05 0.05 0.05 0.05 0.06 0.06 0.06 0.06 0.06
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Turbidity (NTU
)Lake Huron WTP Avg Daily Turbidity Readings (2005 ‐ 2013)
Lake Huron Water Applied Water (to Filters) Filtered Water
JANMAX: 14.70
FEBMAX: 14.76
MARMAX: 13.32
APRMAX: 11.00
OCTMAX: 17.71
DECMAX: 18.88
NOVMAX: 11.58
MAYMAX: 6.70
JUNMAX: 3.98
JULMAX: 2.26
AUGMAX: 1.89
SEPMAX: 3.56
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Figure6‐3:FrequencyPlotofallMaximumDailyTurbidityReadings‐LakeHuronSourceWater,2005to2013
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 5 10 15 20 25
% of Tim
e Exceed
ed
Turbidity (NTU)
Lake Huron WTP Max Daily Turbidity (2005 ‐ 2013)
Lake Huron Water Turbidity
Applied Water Turbidity
Filtered Water Turbidity
MAX: 0.2 NTU MAX: 5.0 NTU MAX: 21.8 NTU
99th %'ile (NTU):Lake: 18 Settled: 2.1Filtered: 0.12
95th %'ile (NTU):Lake: 6.8 Settled: 0.95Filtered: 0.10
50th %'ile (NTU):Lake: 0.85 Settled: 0.40Filtered: 0.07
5th %'ile (NTU):Lake: 0.30 Settled: 0.20Filtered: 0.05
1st %'ile (NTU):Lake: 0.25 Settled: 0.15Filtered: 0.05
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0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0.00 0.50 1.00 1.50 2.00 2.50
% of Tim
e Exceed
ed
TOC (mg/L)
Lake Huron WTP TOC (2010 ‐ 2013)
Lake Huron TOC(mg/L)
Treated Water TOC(mg/L)
Max (mg/L):Lake: 2.28 Treated: 1.95
Min (mg/L):Lake: 1.32Treated: 1.14
50th %'ile (mg/L):Lake: 1.49 Treated: 1.31
Figure6‐4:MonthlyTOCData‐LakeHuronSourceWaterandTreatedWater2010to2013
Figure6‐5:FrequencyPlotofallMonthlyTOCData‐LakeHuronSourceWaterandTreatedWater,2010to2013
1.581.56
1.461.48
1.51
1.351.32
1.49
1.44
1.51
1.47
1.43 1.44
1.56 1.57
1.51
1.581.55
2.28
1.36
1.46
1.70
1.40
1.30
1.20
1.15
1.27
1.37
1.26
1.22
1.38
1.311.34
1.21
1.31
1.14
1.30
1.26
1.64
1.42
1.31
1.95
1.37 1.36
1.50
1.30
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4TO
C (mg/L as C)
Lake Huron WTP Monthly TOC (2010 ‐ 2013)
Lake Huron Treated Water
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Figure6‐6:MonthlyAverageCyanobacteria(blue‐greenalgae)andDiatomCounts‐LakeHuronSourceWater,2005to2013(MaximumValuesarealsoShownontheChart)
137 13
219 12 17 15 11 8 10 11
2 0 2 9 7 513 10 5 4 2 1
0
100
200
300
400
500
600
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
# per m
LLake Huron WTP Avg Algae Concentrations (2005 ‐ 2013)
Diatoms Blue‐Green Algae
JANMAX: 140 (Diatoms)MAX: 60 (Blue Green)
FEBMAX: 0 (Diatoms)MAX: 90 (Blue Green)
MARMAX: 170 (Diatoms)MAX: 80 (Blue Green)
APRMAX: 220 (Diatoms)MAX: 330 (Blue Green)
MAYMAX: 140 (Diatoms)MAX: 410 (Blue Green)
JUNMAX: 160 (Diatoms)MAX: 500 (Blue Green)
JULMAX: 240 (Diatoms)MAX: 344 (Blue Green)
AUGMAX: 130 (Diatoms)MAX: 242 (Blue Green)
SEPMAX: 120 (Diatoms)MAX: 150 (Blue Green)
OCTMAX: 160 (Diatoms)MAX: 360 (Blue Green)
NOVMAX: 150 (Diatoms)MAX: 130 (Blue Green)
DECMAX: 120 (Diatoms)MAX: 100 (Blue Green)
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Figure6‐7:FrequencyPlotofallCyanobacteria(blue‐greenalgae)CountsandDiatomCountsLakeHuronSourceWater,2005to2013
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 100 200 300 400 500 600
% of Tim
e Exceeded
Count
Lake Huron Algae (2005 ‐ 2013)
Diatoms
Blue‐Green
99th %'ile:Diatoms: 160 Blue‐Green: 240
95th %'ile:Diatoms: 50 Blue‐Green: 40
50th %'ile:Diatoms: 0 Blue‐Green: 0
5th %'ile :Diatoms: 0 Blue‐Green: 0
1st %'ile:Diatoms: 0Blue‐Green: 0
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Figure6‐8presentsthemicrobialdatafortotalcoliformandFigure6‐9presentsfrequencydataforHPC.TotalcoliformandHPCsamplesareanalyzeddailyonthesourcewater.Thetotalcoliformresultsarelowandoftennon‐detectableduringthewinterandearlyspring.ThetotalcoliformconcentrationspeakduringAugustthroughOctoberreachingadailymaximumof345cfu/100mL.E.coliisnotmonitoredandsocouldnotbeassessed.HPCdatareachamaximumvalueofapproximately300permLwithasingleoutlierof785permL.AsdiscussedinTM‐8,DWSDhasnotdetectedGiardiaorCryptosporidiumintheLakeHuronwatersource.Thesourcewaterisofhighqualityintermsofmicrobialcontaminants.
Figure6‐8:MonthlyMaximumTotalColiform‐LakeHuron,2011to2012
0
50
100
150
200
250
300
350
400
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Max of Daily Values
#/100 m
L
Monthly MaximumTotal Coliform Lake Huron
2011
2012
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Figure6‐9:MonthlyMaximumTotalColiform‐LakeHuron,2011to2012
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 100 200 300 400 500 600 700 800 900
% of Tim
e Exceeded
Count
Lake Huron HPC (2005 ‐ 2013)
Raw Water HPC
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Figure6‐10showsthetemperaturefrequencyplot.Asistypicalinanorthernclimatethereisvariationintemperaturefrom0.5to26degreesC.
Figure6‐10:FrequencyPlotofTemperature‐LakeHuron,2005to2013
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0.0 5.0 10.0 15.0 20.0 25.0 30.0
% of Time Exceed
ed
Temp (deg C)
Lake Huron Water Temperature (2005 ‐ 2013)
Water Temperature (deg C)
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Figures6‐11andFigure6‐12showalumandcoagulantaidpolymerdosages,respectively.Alumuseishigherinthewinter.Coagulantaiddosagesarerelativelyconstant.AfrequencyplotisshowninFigure6‐13.
Figure6‐11:MonthlyAverageAlumDosages‐LakeHuron,2005to2013(DataInclude2StandardDeviations)
1.051.10
1.02
0.88
0.770.71 0.68
0.73 0.75 0.74 0.73
0.84
0.00
1.00
2.00
3.00
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Alum (mg/L)
Lake Huron WTP Alum Dosage (2005 ‐ 2013)
Alum (mg/L)
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Figure6‐12:MonthlyAverageCoagulantAidDosages ‐ LakeHuron,2005to2013(Datainclude2StandardDeviations)
0.070.06
0.07
0.060.06
0.05
0.04 0.040.05
0.06 0.060.07
0.00
0.05
0.10
0.15
0.20
0.25
0.30
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Coagulant Aid (mh/L)
Lake Huron WTP Avg Daily Coagulant Aid Dosage (2005 ‐ 2013)
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Figure6‐13:FrequencyPlotofAlumandCoagulantDosages‐LakeHuron,2005to2013
Intermsofdiatomandcyanobacteria(blue‐greenalgae)counts,maximumvaluesarealsoimportant.Themaximumvaluefordiatomcountsof240permLoccursinJulyandthemaximumblue‐greenalgaecountof500permLoccursinJune.
Table6‐1showsthebenchmarkvaluesforeachparameterbasedonKawamura,2000.Basedonthebenchmarks,therawwaterqualityofLakeHuronissuitablefordirectfiltrationyear‐roundbasedonanassessmentofwaterqualityonly.Additionalparameterssuchascolorandalgalbiomassarealsocitedaskeyparametersfordirectfiltrationanalysis.FurtherstudyisrecommendedtoconfirmthevaluesoftheseparametersinLakeHuronWTPwater.
Table 6‐1: Summary of Relevant Water Quality Data and Direct Filtration Recommended Benchmarks
Parameter 50th Percentile 95th Percentile 99th Percentile
Kawamura (2000)
Benchmark Value
Lake Huron Turbidity (NTU)
0.85 6.8 18.0 Maximum
< 20.0
Lake Huron TOC
(mg/L as C) 1.49 1.70 2.28 (max) Maximum < 2.50
Diatom Counts (#/mL) 0 50 140 Maximum
< 1,000
Cyanobacteria (Blue‐Green Algae) Counts (#/mL)
0 40 260 Maximum
< 1,000
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0.00 0.50 1.00 1.50 2.00 2.50
% of Time Exceeded
Dosage (mg/L)
Lake Huron WTP Coagulant Chemicals (2005 ‐ 2013)
Alum (mg/L)
Coagulant Aid (mg/L)
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6.3 Water Quality Correlations FromFigure6‐14,alumdosagetrendswithrawwaterturbiditiestoproducerelativelyconsistentsettledwaterturbidity.Thecoagulationandsettlingprocessremovedapproximately60‐75%ofrawwaterturbiditypriortofiltration.ThisislowcomparedtoconventionaltreatmentprocessesandislikelyduetothelackofadequatesettlingtimeandsludgeremovalatLakeHuron.However,duringthemonthofApril,thereisaslightupsetinthesettledwaterturbidity.Duringthesespringevents,DWSDusesafilteraidpolymertoimprovefiltrationperformance.
Diatomsareknowntobeparticularlydifficulttosettle,evenaftercoagulationoroxidation.However,despitetheperceivedminimaleffectofcoagulationondiatomremoval,coagulationandflocculationarestillrequiredtoproduceafilterableflocfordiatomandalgaeremovalbythefiltersinadirectfiltrationmode.Further,filteraidpolymeriscurrentlynotfedyear‐round;currentlyitisonlyfedfromNovemberthroughMay.Filteraidpolymersaretypicallyusedatdirectfiltrationfacilitiesandconversionofthefilterstodirectfiltrationmayrequirethischangeinoperations.AdditionoffilteraidpolymerduringthemonthsofJunethroughOctobershouldbeinvestigated.Further,alternativecoagulantssuchaspoly‐aluminumchloride,ferricsulfate,orferricchlorideshouldbeevaluatedinjartestsandatfull‐scaletoproduceafilterableflocbyDFatlowerdosagestoextendfilterrunsandlowerfilteredwaterturbidity.
Figure6‐14:ComparisonofSourceWaterTurbiditywithChemicalDosages‐LakeHuron,2005to2013
0.00
1.00
2.00
3.00
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Alum Dosage / Coagulant Aid Dosage (mg/L) / Turbidity (NTU
)
Lake Huron WTP Average Chemical Dosages with Average of Max Turbidity Readings (2005 ‐ 2013)
Alum (mg/L) Coagulant Polymer (mg/L) Lake Huron Water Turbidity
Settled Water Turbidity Filtered Water Turbidity
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Figure6‐15showstherelationshipbetweenchemicaladditionandTOCremoval.Thecoagulationandsettlingprocessremovedonly5‐20%ofrawTOClikelyduetothelackofadequatesettlingtimeandsludgeremovalexperiencedinatypicalconventionaltreatmentplant.BecauseDWSDsrawwaterTOCislessthan2.0mg/L,noremovalofTOCisrequiredbycoagulation.Fordirectfiltration,itmaybepossibletoremove10‐15%ofrawTOC,plusalgal‐derivedtasteandodorremovalbyoperatingfiltersinbiologicalmode.
Figure6‐15:ComparisonofTOCandChemicalDosages‐LakeHuron,2005to2013
6.4 Plant Capacity TheLakeHuronWaterTreatmentPlantiscurrentlyallowedanoperatingcapacityof400MGD.However,theMDEQhasindicatedthatthisisbasedonperformanceandnotonthetraditionaldefinitionofratedcapacity.Iftheplantcapacityweretoberatedastypicallydone,thecapacitywouldbelimitedto300MGD.HigherplantproductionrateswouldrequiredailyCTcalculations.MDEQwilllikelyre‐ratetheplantatthelowercapacityifDWSDdecidestopursueconvertingtheplanttodirectfiltration(personalcommunication,December2013).ThereforeanyfutureexpansionoftheLakeHuronWTPwouldneedtoincorporatetherevisedcapacityandanyincreasewouldneedtoincludethe100MGDreduction.PotentiallyademonstrationstudytoestablishplantfunctionallyatahighertreatmentratecouldbeconductedifMDEQconcurredwiththatpotentialapproach.
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7.0 Recommendations on Direct Filtration ThismemorandumhasrevieweddirectfiltrationfeasibilityattheLakeHuronWTPbasedonwaterqualityalone.Waterqualityappearstobecurrentlyacceptableforuseinadirectfiltrationtreatmentprocess.Thenextstepstopursuethisoptionaretoreviewthefollowingparameters:
1. MeetwiththeMDEQtoreviewanypilotordemonstrationworkrequirementsandcollectanyadditionaldatarequired.Whilenewwatertreatmentplantsarerequiredtoconductpilotstudiesper10‐States,convertinganexistingtreatmentplanttodirectfiltrationmayonlyrequirein‐plantdemonstrationstudies.
2. Reviewexistingtreatmentprocessesrelativetotypicaldirectfiltrationdesignparameters.Theseinclude:
a. Filterdesignparameters:mediatype,mediaconfiguration,filterloadingrate,maximumavailablefilteringheadandhistoricalfiltertreatmentperformancewhenoperatedinconventionalanddirectfiltrationmodesincludingfilterloadingrate,filterruntime,unitfilterrunvolumes,backwashfrequency,andheadlossaccumulationrates.Reviewoftheseparameterswillbeimportanttodeterminewhatupgradeswillberequired,ifany,toconverttoyear‐rounddirectfiltration..
b. Designandoperationalinformationasmentionedabovecanbecomparedagainstindustrybestpracticesfordirectfiltration.Forexample,experiencehasshownthatadeep‐bedcoarsemonomediafiltershouldhavegreatercapacitytocopewithalgalanddiatombloomswithreasonablefilterrunsthantraditionaldual‐mediabedswith1.0mmeffectivesizeanthracite.
c. Conductpilotand/orfull‐scaleevaluationsifrequiredtovalidateyear‐rounddirectfiltrationprocessatLakeHuron.Bench‐scaletestsshouldalsobeperformedtoscreenalternativecoagulantsandpolymersforcoldwatercoagulationtoproduceafilterablefloc.Polyaluminumchloride(PACL)maybeapromisingcoagulantforcoldwaterdirectfiltrationapplication.Filteraidsshouldalsobeconsideredforyear‐roundapplicationatlowdoses.
d. CompletesurveyofotherdirectfiltrationplantstreatingLakeHuronwatersuchastheLakeHuronplantreferencedinFoley,1981.
e. Basedontheoutcomesoftheabovesteps,prepareprocessdesigncriteriaandcostestimatesfordirectfiltrationupgradesforLakeHuronWTP.
8.0 References Foley,P.D.1981,ExperiencewithDirectFiltrationatOntario’sLakeHuronTreatmentPlant,JournalAWWA.
Kawamura,Susumu.IntegratedDesignofWaterTreatmentFacilities.JohnWileyandSons,NewYork;2ndEd,2000.
RecommendedStandardsforWaterWorks(10‐States),2012.
WaterPRO,Copyright1996–2011SchottSoftware.PublishedbyChemSW,Inc.
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Appendix A
DWSD Monitoring Schedule
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Appendix B
Detroit Customer Complaint Form
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Appendix C
Sample Siting Plan
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Appendix D
DWSD LIMS General Requirements
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