SouthWestSouthWestWater CompanyWater Company

What a utility needs What a utility needs What a utility needs What a utility needs to consider when to consider when

converting a system converting a system converting a system converting a system to surface water.to surface water.

Presented by: JR ReavisPresented by: JR Reavis

PUBLIC OPINIONPUBLIC OPINION

2

WHAT PEOPLE THINK WHEN YOU TELL THEM THEY ARE DRINKING TREATED SURFACE (LAKE OR RIVER WATER)

3

Public OpinionPublic Opinion●● Most people don’t understand why they are being forced Most people don’t understand why they are being forced ●● Most people don t understand why they are being forced Most people don t understand why they are being forced

to convert to surface waterto convert to surface waterGround subsidence, aquifer depletion or costGround subsidence, aquifer depletion or cost

●● Most customers can’t believe it could cost moreMost customers can’t believe it could cost moreIf ’ t th t i b i t d h h ld If ’ t th t i b i t d h h ld If you’re not one that is being converted why should you If you’re not one that is being converted why should you paypay

●● Most people assume that ground water is pristine and all Most people assume that ground water is pristine and all surface water is of low quality and less safe to drinksurface water is of low quality and less safe to drink

All drinking water, including bottled water, may reasonably All drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some be expected to contain at least small amounts of some contaminants contaminants Surface water (source water) does have a higher potential Surface water (source water) does have a higher potential f t i t d th t i h th it i d f t i t d th t i h th it i d for contaminants and that is why the monitoring and for contaminants and that is why the monitoring and treatment standards are higher for surface water treatmenttreatment standards are higher for surface water treatmentThe presence of contaminants does not necessarily indicate The presence of contaminants does not necessarily indicate that the water poses a health risk, that is why the EPA and that the water poses a health risk, that is why the EPA and TCEQ set limits on contaminants that pose a health riskTCEQ set limits on contaminants that pose a health riskTCEQ set limits on contaminants that pose a health riskTCEQ set limits on contaminants that pose a health riskFact! Both are safe when properly treated, both are Fact! Both are safe when properly treated, both are monitored to ensure public safety, both must meet rigorous monitored to ensure public safety, both must meet rigorous drinking water standards drinking water standards

4

WHAT NEEDS TO BE CONSIDERED?WHAT NEEDS TO BE CONSIDERED?●● Why convert to surface water? Why convert to surface water? Why convert to surface water? Why convert to surface water? ●● Is there really a difference in water characteristics?Is there really a difference in water characteristics?●● CostCost

Capital investmentsGeneral operationGeneral operation

●● Increased monitoring to maintain water qualityIncreased monitoring to maintain water quality●● Increased need for treatment expertiseIncreased need for treatment expertise●● Changes to system operationChanges to system operation

d dNew treatment systems and system upgrades Maintenance of standby well systemsStaffing and licensing requirement

●● Water Quality IssuesWater Quality IssuesWhy chloramine disinfection?Water age management

Water storageSystem flushing

Disinfection schemesDisinfection schemesHigher formation potential for disinfection byHigher formation potential for disinfection by--product and other product and other regulated contaminantsregulated contaminants

●● Relationship with your water wholesalerRelationship with your water wholesaler

5

WHY CONVERT TO SURFACE WATER?WHY CONVERT TO SURFACE WATER?

●● Your utility may be required to participated in Your utility may be required to participated in a ground water reduction program (Subsidence a ground water reduction program (Subsidence or Conservation Districts: Harris Galveston, or Conservation Districts: Harris Galveston, Fort Bend County, Lone Star, etc…)Fort Bend County, Lone Star, etc…)

●● Demand has outstripped available ground Demand has outstripped available ground water supplywater supplywater supplywater supply

●● Ground water may contain regulated Ground water may contain regulated contaminants that are difficult to treat or contaminants that are difficult to treat or would be more costly to treat than using an would be more costly to treat than using an would be more costly to treat than using an would be more costly to treat than using an alternate surface water source (Arsenic, alternate surface water source (Arsenic, Fluoride, Radon, etc…)Fluoride, Radon, etc…)It’ he pe to b te f om hole le It’ he pe to b te f om hole le ●● It’s cheaper to buy water from a wholesaler It’s cheaper to buy water from a wholesaler than it is to rehab or develop new ground than it is to rehab or develop new ground water sourceswater sources

6

IN THE HOUSTON AREA SUBSIDENCE IS IN THE HOUSTON AREA SUBSIDENCE IS THE PREDOMINANT DRIVING FORCE THE PREDOMINANT DRIVING FORCE

BEHIND THE CONVERSIONBEHIND THE CONVERSION

7

HOUSTON AREA SUBSIDENCE MAP

8http://pubs.usgs.gov/ha/ha730/ch_e/gif/E064.GIFhttp://pubs.usgs.gov/ha/ha730/ch_e/gif/E064.GIF

GROUNDWATER LEVELS IN THE HOUSTON GROUNDWATER LEVELS IN THE HOUSTON AREA FROM 1931 TO 1970AREA FROM 1931 TO 1970

9

GENERAL GENERAL GENERAL GENERAL DIFFERENCESDIFFERENCES

SURFACE vs. GROUND SURFACE vs. GROUND WATERWATERWATERWATER

10

Ground WaterGround Water• Generally higher levels of

inorganics, low or no organics• Hydrogen sulfate iron

Surface WaterSurface Water• Generally higher level or

organics, inorganics less of an issue• Hydrogen sulfate, iron,

manganese and other constituents can cause taste, odor and color problems

• Low DBP formation potentiali i ll ili i

issue• Organics can cause taste, odor

and color issues• Higher DBP formation potential • Generally requires more

hi i d di i f i• Historically most utilities use free chlorine to disinfect (simple disinfection scheme)

• Water age is not an less of an issue because most ground

sophisticated disinfection scheme, chloramine disinfection is commonly used

• Water age is a big consideration (storage and flushing are very ssue because ost g ou d

water lacks organics to exert a demand on chlorine

• System wide water age management is less of an issue because water does not

(sto age a d us g a e e yimportant)

• System wide management is required to maintain water quality

• More complicated treatment because water does not degrade in the system as easily

• Water chemistry is relatively simple, or at least it doesn’t change frequently M it i i t

• More complicated treatment needed (can change frequently for multitude of reasons)

• More complicated monitoring requirements, higher level of

t kill i d • Monitoring requirements are relatively simple, less technical skills required to operate

• Operator time requirements are relatively low

operator skills required • Time demand on the operator is

much higher

11

y

COSTSCOSTSCapital &Capital &Capital &Capital &

GENERAL OPERATING GENERAL OPERATING

12

CAPITAL COSTSCAPITAL COSTS

● New treatment equipment● New treatment equipmentInstallation of storage tanks, high service pumps, chemical feed equipment, instrumentation, etc…

● Modifications to existing water storage tanks● Modifications to existing water storage tanksAlternate fill & take points, monitoring equipment, mixers

● Improvements to existing chemical feed equipmentPump replacements metering & monitoring equipment Pump replacements, metering & monitoring equipment (SCADA?)

● Piping and valve replacementsIn the facility and in the systemIn the facility and in the systemInstallation of system interconnects, valves, PRVs and meters

● Modifications to existing well systems● Modifications to existing well systemsBlow offs, SCADA control, monitoring, etc… (Just to insure reliability when needed.)

● Costs associated with capping abandoned wells

13

● Costs associated with capping abandoned wells

GENERAL OPERATING COSTSGENERAL OPERATING COSTS● Increased operator presence● Increased operator presence

Higher degree of compliance Higher degree of monitoring samplingIncreased distribution presence (system flushing & p ( y gcustomer complaint response)Higher need for technical support Increased maintenance support for monitoring and chemical feed equipmentchemical feed equipment

● Increased costs associated with maintaining standby well systems

● Increased chemical costs to maintain disinfectant ● Increased chemical costs to maintain disinfectant residuals

● Increased laboratory fees associated with a higher level of monitoring g

● Increased costs associated with purchasing surface water

● Increased need for system flushing

14

MONITORINGMONITORING

15

INCREASED MONITORING TO INCREASED MONITORING TO MAINTAIN WATER QUALITYMAINTAIN WATER QUALITY

● Unless mandated by special need, ground water facilities do not require extensive online monitoring

● Surface water plants have specific grab and online ● Surface water plants have specific grab and online monitoring requirements in order to maintain regulatory compliance

● Repump stations may require online monitoring to ● Repump stations may require online monitoring to insure water quality

● Whether being treated or repumped, surface water requires more extensive process monitoring to insure requires more extensive process monitoring to insure water quality

● Operators will need a higher level of treatment knowledge to deal with the more complicated treatment knowledge to deal with the more complicated treatment issues associated with surface water

● Process monitoring is the best tool the operator has to address problems before they become big issues

16

address problems before they become big issues

Typical chemical & sampling scheme for d t t i t a ground water system prior to

chloramine conversion

SampleSample

1 1 -- Free chlorine sample in the plantFree chlorine sample in the plant

ClCl22

GSTGSTGSTGST

WellWellDistributionDistribution

17

Typical chemical application & sampling points when purchasing surface water points when purchasing surface water from a wholesaler with no well water

being usedg4 4 -- Free chlorine samples in the plantFree chlorine samples in the plant4 4 -- Total chlorine samples in the plantTotal chlorine samples in the plant4 4 –– Monochloramine samples in the plantMonochloramine samples in the plant4 4 –– Free ammonia samples in the plantFree ammonia samples in the plant

ClCl22ClCl22NHNH33

NHNH33

SampleSampleSampleSample SampleSampleSampleSample

4 4 –– Free ammonia samples in the plantFree ammonia samples in the plant

ClCl22 33

GSTGSTPurchased Water

(chloraminated ) DistributionDistribution(chloraminated )

18

Typical chemical application & sampling points when purchasing surface water points when purchasing surface water from a wholesaler with a well system

being used5 5 -- Free chlorine samples in the plantFree chlorine samples in the plant5 5 -- Total chlorine samples in the plantTotal chlorine samples in the plant5 5 –– Monochloramine samples in the plantMonochloramine samples in the plant5 5 –– Free ammonia samples in the plantFree ammonia samples in the plant

ClCl22 ClCl22NHNH33

NHNH33

SampleSampleSampleSample SampleSample

5 5 Free ammonia samples in the plantFree ammonia samples in the plant

33

GSTGSTDistributionDistribution

ClCl22NHNH33

WellWellSampleSample SampleSample

19

Purchased Water

(chloraminated )

THINGS TO REMEMBER ABOUT THINGS TO REMEMBER ABOUT ONLINE MONITORING EQUIPMENTONLINE MONITORING EQUIPMENT

●● When used properly online monitoring When used properly online monitoring instruments are great diagnostic tools instruments are great diagnostic tools

●● Online monitoring equipment is only as good Online monitoring equipment is only as good ●● Online monitoring equipment is only as good Online monitoring equipment is only as good as the maintenance performed on themas the maintenance performed on them

●● Caution should be used when online Caution should be used when online monitoring equipment is used to control monitoring equipment is used to control monitoring equipment is used to control monitoring equipment is used to control chemical feed equipmentchemical feed equipment

Online equipment fails and often generate false dataOnline equipment fails and often generate false datal l ll l lTotal reliance upon online monitoring equipment Total reliance upon online monitoring equipment

without operator input will result in catastrophic without operator input will result in catastrophic treatment failure treatment failure Online monitoring equipment can not replace Online monitoring equipment can not replace Online monitoring equipment can not replace Online monitoring equipment can not replace operator knowledgeoperator knowledgeA good operator always assumes the online A good operator always assumes the online equipment is wrong Verify! equipment is wrong Verify! Verify!Verify! Verify!Verify!

20

equipment is wrong. Verify! equipment is wrong. Verify! Verify!Verify! Verify!Verify!

TREATMENT TREATMENT EXPERISEEXPERISEEXPERISEEXPERISE

21

INCREASED NEED FOR TREATMENT INCREASED NEED FOR TREATMENT EXPERTISEEXPERTISE

Ground WaterGround Water● Most ground water operators

have long term familiarity with the ground water operation but

Surface WaterSurface Water● Because of the organic nature

of surface water, quality changes can occur frequently in the ground water operation but

lack familiarity with surface water treatment issues making technical support a necessity

● Few changes occur from day-to-day in ground water quality

changes can occur frequently in a surface water system

● It is often hard to diagnose the problem because of the complexity of the source water (What worked the previously day in ground water quality

● Ground water lacks the organic constituents that create constantly changing treatment needs

(What worked the previously may not work this time)

● Treatment needs change with the seasons or weather conditions

● Once a successful treatment scheme is determined it is seldom changed

● Problems associated with DBP formation are less likely with

● The distribution system is more biologically active and needs to be addressed accordingly

● DBP formation potential is more likely due to the presence of formation are less likely with

water that contains little or no organic material

likely due to the presence of organics in the source water

● More extensive regulatory compliance requirements than those required for ground water

22Diagnosis and reaction to treatment issues quickly Diagnosis and reaction to treatment issues quickly

are crucial for systems using surface water!are crucial for systems using surface water!

SYSTEM OPERATIONSSYSTEM OPERATIONS

23

CHANGES TO SYSTEM OPERATIONCHANGES TO SYSTEM OPERATION● New treatment systems and system upgradesNew treatment systems and system upgrades

Operating a surface water system will require the addition of numerous new chemical feed systems: coagulant, polymers, ammonia, pH adjustment systems, oxidants (KMnO4, chlorine dioxide, ozone), fluoride, etc…

Higher number of feed systems will require greater operator knowledge and skills in order to make chemical operator knowledge and skills in order to make chemical dosages changes and perform monitoring testsHigher importance needs to be placed on equipment maintenance

E i d d i – Equipment redundancy is a must– The system should have a managed maintenance system

to track routine, corrective and emergency repairs, as well as manage parts inventoryB d i f i l d di i i – Budgeting for equipment replacement and reconditioning is even more important due to the number of equipment items and the importance that each item has in the performance of the plant Maintaining monitoring equipment will require more time

24

– Maintaining monitoring equipment will require more time and expertise on the maintenance staff

Possible increases in time spent by Possible increases in time spent by operators taking additional samplesoperators taking additional samplesoperators taking additional samplesoperators taking additional samples

Old Well Old Well SystemsSystems

*Surface Water *Surface Water OnlyOnly

*Surface *Surface Water with Water with Well Water Well Water S l tS l tSupplementSupplement

Free ChlorineFree Chlorine 2 @ 30 sec each2 @ 30 sec each 4 @ 30 sec each4 @ 30 sec each 5 @ 30 sec each5 @ 30 sec each

Total ChlorineTotal Chlorine nana 4 @ 1 min 30 sec each4 @ 1 min 30 sec each 5 @ 1 min 30 5 @ 1 min 30 sec eachsec eachsec eachsec each

Monochloramine/Monochloramine/Free AmmoniaFree Ammonia nana 4 @ 12 min each4 @ 12 min each 5 @ 12 min each5 @ 12 min each

Sample Sample 2 @ 5 minutes2 @ 5 minutes 4 @ 5 min each4 @ 5 min each 5 @ 5 min each5 @ 5 min eachCollection TimeCollection Time 2 @ 5 minutes2 @ 5 minutes 4 @ 5 min each4 @ 5 min each 5 @ 5 min each5 @ 5 min each

Sample RerunsSample Reruns 1 @ 30 sec each1 @ 30 sec each 2 @ 15 min each2 @ 15 min each 2 @ 15 min each2 @ 15 min each

Total Time Total Time ~ 12 minutes~ 12 minutes ~ 1 Hours ~ 1 Hours ~ 2 Hours ~ 2 Hours RequiredRequired ~ 12 minutes~ 12 minutes 46 minutes46 minutes 5 minutes5 minutes

*Although the operator will not always be required to sample all location, if *Although the operator will not always be required to sample all location, if problems exist the operator will be doing at least the number of samples listed problems exist the operator will be doing at least the number of samples listed

above. This estimate does not include time spent checking chemical feed above. This estimate does not include time spent checking chemical feed

25

systems.systems.

Possible increases in time & money spent Possible increases in time & money spent by chlorine and maintenance techniciansby chlorine and maintenance techniciansby chlorine and maintenance techniciansby chlorine and maintenance technicians

Old Well Old Well SystemsSystems

Surface Water Only or Surface Water Surface Water Only or Surface Water with Well Water Supplementwith Well Water Supplement

OnOn line Chlorine line Chlorine (None)(None) (Two or more)(Two or more)OnOn--line Chlorine line Chlorine AnalyzerAnalyzer Generally done Generally done

by grab sampleby grab sampleMost systems will have 1 on both the Most systems will have 1 on both the

incoming surface line and the outgoing lineincoming surface line and the outgoing line

Monochloramine Monochloramine / Free Ammonia/ Free Ammonia

(None)(None)It wasn’t It wasn’t

(Possibly two or more)(Possibly two or more)Most systems will have 1 on both the Most systems will have 1 on both the / Free Ammonia/ Free Ammonia

necessarynecessary incoming surface line and the outgoing lineincoming surface line and the outgoing line

Surface Flow Surface Flow Meter/PRVsMeter/PRVs (None)(None)

Inspections and calibrations are part of Inspections and calibrations are part of routine maintenance (an expense to the routine maintenance (an expense to the

district)district)

Chemical Chemical metering metering devisesdevises

(One) (One) ChlorinatorChlorinator

(Possibly as many as six)(Possibly as many as six)Depending on configuration, 3 units for each Depending on configuration, 3 units for each

ammonia and chlorineammonia and chlorine

Each additional piece of equipment will require additional time on the part of the Each additional piece of equipment will require additional time on the part of the Each additional piece of equipment will require additional time on the part of the Each additional piece of equipment will require additional time on the part of the maintenance staff. Example: Each of the monochloramine/ammonia analyzers maintenance staff. Example: Each of the monochloramine/ammonia analyzers could require as much as 3could require as much as 3--5 hours a week for the operator/maintenance staff. 5 hours a week for the operator/maintenance staff.

In addition, $3,000 to $4,500 annually should be budgeted for its use (reagents, In addition, $3,000 to $4,500 annually should be budgeted for its use (reagents, parts, required routine maintenance and possible replacement). parts, required routine maintenance and possible replacement).

26

Possible increases in time and money Possible increases in time and money spent in the distribution systemspent in the distribution systemspent in the distribution systemspent in the distribution system

Old Well Old Well SystemsSystems

Surface Water Only or Surface Water Surface Water Only or Surface Water with Well Water Supplementwith Well Water Supplement

(required (required Based on need, it is possible that the Based on need, it is possible that the

FlushingFlushing minimum)minimum)Dead ends Dead ends

once/monthonce/month

system could require as much as 2 to 3 system could require as much as 2 to 3 times as much flushing to maintain water times as much flushing to maintain water

quality.quality.

M i i M i i (most probably (most probably THM, HAATHM, HAA55, HPC, nitrite, nitrate and , HPC, nitrite, nitrate and

i l ill d h i l ill d h Monitoring Monitoring samples for samples for operational operational purposespurposes

( p y( p ynone)none)

It wasn’t It wasn’t necessarynecessary

ammonia samples will need to run on the ammonia samples will need to run on the incoming water, at the high service pumps incoming water, at the high service pumps

and in the system. The frequency will range and in the system. The frequency will range from weekly to monthly depending on from weekly to monthly depending on

conditions within the system.conditions within the system.conditions within the system.conditions within the system.

Monitoring Monitoring sample sample

dk idk i

(none) (none) Generally only Generally only

compliance compliance l l

The only way monitoring samples will be of The only way monitoring samples will be of use is if they are easily tracked and use is if they are easily tracked and

available when needed. It is also one of the available when needed. It is also one of the only tools the client has to address issues only tools the client has to address issues recordkeepingrecordkeeping samples are samples are

trackedtracked

yywith water quality coming from the with water quality coming from the

wholesale supplier.wholesale supplier.

Flushing is a real cost that is realized by the district. More importantly Flushing is a real cost that is realized by the district. More importantly monitoring samples necessary to operate the system properly will be additional monitoring samples necessary to operate the system properly will be additional

27

expenses that the district will incur to insure water quality. expenses that the district will incur to insure water quality.

Don’t forget to budget for maintaining Don’t forget to budget for maintaining standby well systems!standby well systems!

CHANGES TO SYSTEM OPERATIONCHANGES TO SYSTEM OPERATION

● Maintenance of standby well systemsA system seldom used could be more expensive to maintain than one that is used on a routine basisExercising on a routine basis is a must to insure reliability

● Staffing and licensing requirement● Staffing and licensing requirementA more complicated system requires a higher degree of skill on the part of the operatorS it d titi f kill d t ill Scarcity and competition for skilled operators will drive the cost of operation upYou can’t expect to staff a repump station or surface

t l t th d t t water plant the same as a ground water system considering the added in plant and system operating requirements

28

WATER QUALITYWATER QUALITY

29

WATER AGE MANAGEMENT ISSUESWATER AGE MANAGEMENT ISSUES

W t t d t t t b ● Water storage – a ground water system may not be configured properly to manage water age in the storage tanks because historically most storage facilities were designed to:designed to:

Equalized demandsReduce pressure issues in the system Provide a reserve for fire fighting or other emergencies Provide a reserve for fire fighting or other emergencies

● Ground water operating strategy of “keep it full at all times in case of emergency” is no longer a wise operating strategy operating strategy

Deep cycling storage tanks becomes very importantIt is possible that existing storage tanks will need modifications modifications

Baffles, mixers, tank inlets and outlets changed

Elevated storage tanks can be a big concern and need to be managed to prevent aged water problems

30

g p g p

WATER AGE MANAGEMENT ISSUESWATER AGE MANAGEMENT ISSUES● System flushing – Dead end flushing becomes very ● System flushing Dead end flushing becomes very

important to system water quality● Water containing organics (surface water) will

experience chlorine decay more rapidly than systems p y p y yusing ground water

● Customer complaints need to be tracked to determine where problems are occurring (don’t assume dead ends are the only problem areas)are the only problem areas)

● Tracking water quality parameters such as taste, odor, HPCs, chlorine residual, nitrite, nitrates and free ammonia are very importantammonia are very important

● Auto flushers will help control low chlorine residuals, taste and odor complaints and to reduce operator time in the field

● Maintenance of the complete system is more importantTreatment problems don’t stop at the facility fenceTreatment problems are not self correcting

31

BASIC GROUND WATER OPERATIONWell

Cl2Elevated Storage

Well

Well

PumpGroundGround Storage

Well

Elevated

Cl2Cl2

Elevated Storage Storage

Cl2

Ground Storage

Pump Pump

32

BASIC SURFACE WATER OPERATION WHOLESALER TO END USERWHOLESALER TO END USER

RAWRAW PrePre--S di t tiS di t ti

Bar Screen

Rapid Mix

Flocculation

Sedimentation FiltersRAW RAW

SOURCESOURCESedimentationSedimentation Mix

Initial treatment 1st Cl - 2nd NH

Chemical BldChemical Bld

Chemical FeedChemical Feed

1 Cl2 - 2 NH3

RepumpCl2

NH3

Pump

Booster treatment 1st NH3 - 2nd Cl2

StorageStorage

NH3NH3 NH3Cl2

Cl2Cl2

33

Storage

Repump

COMBINE THE TWO AND IT GETS COMPLICATED WellCOMPLICATED

RAWRAW PrePre--S di t tiS di t ti

Bar Screen

Rapid Mix

Flocculation

Sedimentation FiltersCl2

Elevated Storage

Well

RAW RAW SOURCESOURCE

SedimentationSedimentation MixWell

PumpGround

Initial treatment 1st Cl - 2nd NH

Chemical BldChemical Bld

Ground Storage

Well

Elevated

Chemical FeedChemical Feed

1 Cl2 - 2 NH3

RepumpCl2

NH3

Pump

Booster treatment 1st NH3 - 2nd Cl2

Cl2Cl2

Elevated Storage Storage

Cl2

StorageStorage

NH3NH3 NH3Cl2

Cl2Cl2

Ground Storage

Pump Pump

34

Storage

Repump

TREATMENT AND DISINFECTION

35

Chloramination Breakpoint Curve

Understanding Understanding Breakpoint Breakpoint

Ch i t i Ch i t i Chemistry is Chemistry is Critical! Critical!

Chlorine destroyed by

9:1, Cl2:NH3-N

SomeTrichloramines

reducing compounds

, 2 3

36

WHY CHLORAMINE DISINFECTION?WHY CHLORAMINE DISINFECTION?C ’t h ld di i f t t id l i th di t ib ti C ’t h ld di i f t t id l i th di t ib ti ●● Can’t hold a disinfectant residual in the distribution Can’t hold a disinfectant residual in the distribution systemsystem

Free chlorine is a stronger disinfectant that quickly reacts Free chlorine is a stronger disinfectant that quickly reacts with anything that will oxidizewith anything that will oxidize

THMs (a regulated disinfection byTHMs (a regulated disinfection by--product) rapidly form in the product) rapidly form in the presence of free chlorine and organicspresence of free chlorine and organicsIn the presence of organics the free chlorine disinfectant In the presence of organics the free chlorine disinfectant residual is quickly consumed residual is quickly consumed

Chloramines are a weaker disinfectant but more stable than Chloramines are a weaker disinfectant but more stable than Chloramines are a weaker disinfectant but more stable than Chloramines are a weaker disinfectant but more stable than chlorinechlorine

Weaker, Less reactive disinfectant, that is why is it not used as Weaker, Less reactive disinfectant, that is why is it not used as the primary disinfectant in water treatment, but when used in the primary disinfectant in water treatment, but when used in conjunction with a stronger disinfectant it is very effectiveconjunction with a stronger disinfectant it is very effectivej g yj g yProvides a higher residual in the distribution system Provides a higher residual in the distribution system

●● In some cases a utility may want to convert to In some cases a utility may want to convert to chloramine disinfection even though they are not chloramine disinfection even though they are not converting to surface waterconverting to surface waterconverting to surface waterconverting to surface water

Utilities that frequently use an emergency interconnect with Utilities that frequently use an emergency interconnect with a neighboring system that does utilizes chloramine a neighboring system that does utilizes chloramine disinfection in their distribution systemdisinfection in their distribution systemYou will have problems in the distribution if you try to You will have problems in the distribution if you try to

37

You will have problems in the distribution if you try to You will have problems in the distribution if you try to operate a system using both chlorine and chloraminesoperate a system using both chlorine and chloramines

Chlorine/Chloramine Interaction in Chlorine/Chloramine Interaction in the Distribution Systemthe Distribution Systemthe Distribution Systemthe Distribution System

Transition Transition ZoneZone

Very Very Unhappy Unhappy

CustomersCustomers

Low Low Chlorine Chlorine

Fewer Fewer Customer Customer

ComplaintsComplaints

Good Good Chlorine Chlorine

Fewer Fewer Customer Customer

ComplaintsComplaints

Good Good Chlorine Chlorine

From From Wholesaler Wholesaler

with with Chl iChl i

Well Water Well Water or System or System using Free using Free

ZoneZone

ResidualsResiduals

Bad Taste & Bad Taste & Odor IssuesOdor Issues

High Levels High Levels of DBPsof DBPs

ResidualsResiduals ResidualsResidualsChloraminesChloraminesus g eeus g eeChlorineChlorine

●● YouYou can’tcan’t runrun aa systemsystem withwith chlorinechlorine andand chloramineschloraminessimultaneouslysimultaneously becausebecause itit createscreates aa transitiontransition zonezone withwith veryveryunhappyunhappy customerscustomers..

●● DependingDepending onon systemsystem pressures,pressures, thethe transitiontransition zonezone cancan movemove..YouYou cancan telltell thisthis byby monitoringmonitoring customercustomer complaintscomplaints

38

YouYou cancan telltell thisthis byby monitoringmonitoring customercustomer complaintscomplaints..

Chl i R ti ith W tChlorine Reaction with Water

HH

ClCl22 HH22OO HOClHOCl HClHCl++

ClClClCl ClCl ClClOO

HH

+OO

HH

HH

+HH

ChlorineChlorine WaterWater Hypochlorous Hypochlorous AcidAcid

Hydrochloric Hydrochloric AcidAcid

+ +

39

Monochloramine FormationMonochloramine Formation

HH

HH22OO+HOClHOCl NHNH22ClClNHNH33 +

HH

ClClOO

HH

+OO

HH

+NN

HH

HH

NN

HH

HHClClClCl

HH

hlhl

HHHH

ClCl

WaterWaterHypochlorous Hypochlorous AcidAcid

AmmoniaAmmonia+ +MonochloramineMonochloramine

40

DISINFECTION SCHEMESDISINFECTION SCHEMES

I d t i t i di i f ti id l i th t ● In order to maintain disinfection residuals in the system chloramines may need to be used

● Systems using both ground water and surface water must use the same disinfection scheme

● In order to avoid problems, systems that routinely rely on interconnects with other systems will need to conform to the same disinfection schemes used by the suppliersupplier

● Chlorine chemistry becomes critical when using chloramines

Ratios, dosages and feed rates significantly impact formation potential of DBPsformation potential of DBPsLoss of the chlorine or ammonia feed system even for a short period of time can become a significant compliance problemSystem monitoring both grab and online monitoring is System monitoring, both grab and online monitoring is vitally importantWithout adequate monitoring there is no way to avoid water quality issues

41

PUBLIC HEALTH CONCERNS

42

SURFACE WATER HAS A HIGHER SURFACE WATER HAS A HIGHER FORMATION POTENTIAL FOR FORMING FORMATION POTENTIAL FOR FORMING

DISINFECTION BYDISINFECTION BY PRODUCTS (DBPs) AND PRODUCTS (DBPs) AND DISINFECTION BYDISINFECTION BY--PRODUCTS (DBPs) AND PRODUCTS (DBPs) AND OTHER REGULATED CONTAMINANTSOTHER REGULATED CONTAMINANTS

●● The difference ground water lacks organics and the The difference ground water lacks organics and the ●● The difference, ground water lacks organics and the The difference, ground water lacks organics and the potential to form DBPspotential to form DBPs

DPB formation is impacted by:DPB formation is impacted by:Nature and quality of the source waterNature and quality of the source waterq yq yChlorine/chloramine concentrationsChlorine/chloramine concentrationsChlorine to ammonia ratioChlorine to ammonia ratioTemperatureTemperatureContact time (water age)Contact time (water age)

Cryptosporidium and Giardia are biological contaminants Cryptosporidium and Giardia are biological contaminants that most ground water systems would never deal withthat most ground water systems would never deal with

Both are naturally present in the intestines of most Both are naturally present in the intestines of most Both are naturally present in the intestines of most Both are naturally present in the intestines of most mammals including humans, and are passed into the mammals including humans, and are passed into the environment through urban runoff or sewage disposal environment through urban runoff or sewage disposal system failuresystem failure

43

NITRIFICATIONNITRIFICATION●● Nitrification becomes a big issue when using Nitrification becomes a big issue when using Nitrification becomes a big issue when using Nitrification becomes a big issue when using

chloramines chloramines Nitrification can impacts disinfectant residuals and Nitrification can impacts disinfectant residuals and general water qualitygeneral water qualityg q yg q yMany of the same issues that impact DBP formation Many of the same issues that impact DBP formation impact the nitrification processimpact the nitrification process

Nature and quality of the source waterNature and quality of the source waterChlorine/chloramine concentrationsChlorine/chloramine concentrationsChlorine to ammonia ratioChlorine to ammonia ratioTemperatureTemperatureC t t ti ( t )C t t ti ( t )Contact time (water age)Contact time (water age)

Nitrification is not a self correcting issue, it can’t be Nitrification is not a self correcting issue, it can’t be ignoredignoredThe best treatment strategy is to monitor control The best treatment strategy is to monitor control The best treatment strategy is to monitor, control The best treatment strategy is to monitor, control ammonia levels and reduce water age ammonia levels and reduce water age And don’t forget, it draws the attention of the And don’t forget, it draws the attention of the regulatorsregulators

44

regulatorsregulators

Chloramine Formation and DecayChloramine Formation and Decay

Controlling excess ammonia is a bigger issue than feeding Controlling excess ammonia is a bigger issue than feeding ammonia because as chloramines decay ammonia is ammonia because as chloramines decay ammonia is

released to be reused, either to form more chloramines or released to be reused, either to form more chloramines or as a food source for nitrifying bacteria. as a food source for nitrifying bacteria.

45

Source: http://www.tawwa.org/TW07Proceedings/070412a/WaterTreatment/The%20Ties%20That%20Bind.pdf

as a food source for nitrifying bacteria. as a food source for nitrifying bacteria.

The Nitrification ProcessThe Nitrification Process

AmmoniaAmmonia NitriteNitrite NitrateNitrate

NitrosomonasNitrosomonas

(Ammonia(Ammonia--Oxidizing Bacteria)Oxidizing Bacteria)

NitrobactersNitrobacters

(Nitrite(Nitrite--Oxidizing Oxidizing Bacteria)Bacteria)

AmmoniaAmmonia

(NH(NH33))

NitriteNitrite

(NO(NO22--))

NitrateNitrate

(NO(NO33--))

Optimum ConditionsOptimum Conditions Influencing Factors Influencing Factors Optimum ConditionsOptimum Conditions

pH pH 7.5 7.5 –– 8.58.5

Temp. Temp. 25 25 -- 3030°°CC

Free AmmoniaFree Ammonia

Influencing Factors Influencing Factors

Water TemperatureWater Temperature

Detention TimeDetention Time

Excess AmmoniaExcess Ammonia

Dark EnvironmentDark Environment

Early Warning SignsEarly Warning Signs

Decrease in AmmoniaDecrease in Ammonia

Decrease in ChlorineDecrease in Chlorine

Prevention and ControlPrevention and Control

Decrease Detention TimeDecrease Detention Time

Chloramine ConcentrationChloramine Concentration

Decrease in ChlorineDecrease in Chlorine

Decrease in pHDecrease in pH

Increase in NitriteIncrease in Nitrite

Increase in HPCIncrease in HPC

Decrease Free AmmoniaDecrease Free Ammonia

Increase Disinfection Dosage Increase Disinfection Dosage RatioRatio

Breakpoint chlorinateBreakpoint chlorinate

46Source: Small system Operation and Maintenance (Ken Kerry)Source: Small system Operation and Maintenance (Ken Kerry)

Establish a Flushing Program Establish a Flushing Program

DEALING WITH THE WHOLESALER

47

THINGS TO REMEMBER WHEN YOU BUY THINGS TO REMEMBER WHEN YOU BUY WATER FROM A WHOLESALER THAT WATER FROM A WHOLESALER THAT

PROVIDES TREATED SURFACE WATERPROVIDES TREATED SURFACE WATER

●● The treatment process at the wholesaler plant is criticalThe treatment process at the wholesaler plant is critical●● The treatment process at the wholesaler plant is criticalThe treatment process at the wholesaler plant is criticalIf they get it wrong, it’s wrong everywhere If they get it wrong, it’s wrong everywhere If they have problems, you have problems If they have problems, you have problems If the wholesaler has formed DBPs you can’t remove them If the wholesaler has formed DBPs you can’t remove them If the wholesaler has formed DBPs, you can t remove them If the wholesaler has formed DBPs, you can t remove them easily or cost effectivelyeasily or cost effectively

●● CautionCaution! Don’t assume that anytime there is a water ! Don’t assume that anytime there is a water quality problem it is the wholesalers fault because each quality problem it is the wholesalers fault because each quality problem it is the wholesalers fault because each quality problem it is the wholesalers fault because each time water is retime water is re--chloraminated, or simply given enough chloraminated, or simply given enough time, the possibility that problems can occur increases time, the possibility that problems can occur increases

●● Process control monitoring system entry monitoring Process control monitoring system entry monitoring ●● Process control monitoring, system entry monitoring Process control monitoring, system entry monitoring and communication with your wholesaler are the best and communication with your wholesaler are the best tools you have to insure purchased water qualitytools you have to insure purchased water quality

48

QUESTIONSQUESTIONS:QUESTIONSQUESTIONS:

JR ReavisJR Reavisi l Q li ii l Q li iNational Water Quality DirectorNational Water Quality Director

SouthWest Water CompanySouthWest Water Company281281 216216 35453545281281--216216--35453545

jrreavis@swwc.comjrreavis@swwc.com

49