Potable Reuse for Inland Locations: Pilot Testing Results from Tucson for a New Potable Reuse Treatment SchemeArizona Water Reuse 2015 SymposiumFlagstaff, AZJuly 27-28, 2015

Larry Schimmoller, CH2MMichael Hwang, CH2MJeff Biggs, Tucson Water

Tucson’s Potable Reuse ProjectWhat are Tucson’s drivers for reuse?• Tucson is exploring potable

reuse to diversify their water supply portfolio

• Tucson is transitioning to more renewable water supplies

What treatment is needed? • MF-RO-UVAOP has been shown to be effective, but Tucson Water

wants to explore alternative treatment methods, while:– Providing multiple barriers for organics and pathogens– Removing salt– Reducing energy consumption– Mitigating concentrate disposal

RO-Based treatment can be expensive, especially at inland locations

$0

$50,000,000

$100,000,000

$150,000,000

$200,000,000

$250,000,000

$300,000,000

$350,000,000

$400,000,000

- 10 20 30 40 50 60 70 80 Plant Capacity (MGD)

Capital Costs

Floc/Sed/O3/BAC/GAC/UV

MF/RO/UVAOP (Ocean Disposal)

MF/RO/UVAOP(mech evap)

MF/RO/UVAOP(evap ponds)

Figures taken from WRRF-10-01. Figures are WateReuse Research Foundation’s Intellectual Property

RO-Based treatment can be expensive, especially at inland locations

$0

$50,000,000

$100,000,000

$150,000,000

$200,000,000

$250,000,000

$300,000,000

$350,000,000

$400,000,000

- 10 20 30 40 50 60 70 80 Plant Capacity (MGD)

Capital Costs

Floc/Sed/O3/BAC/GAC/UV

MF/RO/UVAOP (Ocean Disposal)

MF/RO/UVAOP(mech evap)

MF/RO/UVAOP(evap ponds)

Figures taken from WRRF-10-01. Figures are WateReuse Research Foundation’s Intellectual Property

If RO is not absolutely necessary, explore other

options (especially at inland locations)

Proposed Treatment Scheme

Agua Nueva WRF Secondary

Effluent

SOIL AQUIFER TREATMENTORGANICS

CECsPATHOGENS

SOLIDS

NF CONC.

O3

OZONATION / BAC- GAC PATHOGENSORGANICS

CECs

CL2

POTABLE WATER TO

DISTRIBUTION

SIDE STREAM NFTDS

ORGANICSPATHOGENS

CECs

FREE CHLORINE PATHOGENS

CARTRIDGE FILTER

60%Q

40%Q

Proposed Treatment Scheme

Provides multiple barriers for organics and pathogensRemoves saltReduces energy consumptionMitigates concentrate disposal

Agua Nueva WRF Secondary

Effluent

SOIL AQUIFER TREATMENTORGANICS

CECsPATHOGENS

SOLIDS

NF CONC.

O3

OZONATION / BAC- GAC PATHOGENSORGANICS

CECs

CL2

POTABLE WATER TO

DISTRIBUTION

SIDE STREAM NFTDS

ORGANICSPATHOGENS

CECs

FREE CHLORINE PATHOGENS

CARTRIDGE FILTER

60%Q

40%Q

Other Water Quality Concerns• NDMA

– Significant formation can occur with ozone addition to secondary effluent

– SAT and NF will remove precursors and BAC will remove NDMA formed

• Bromate– Bromide concentrations in secondary effluent are high (0.2 – 0.3 mg/L),

could lead to elevated bromate with ozone addition– Add ozone at sub-residual doses if possible

• TDS– Secondary effluent 650 – 800 mg/L– Goal is < 500 mg/L; side-stream NF treatment

Pilot Testing Project Goals & Phasing

• Primary Goal: Test the viability of the proposed treatment scheme for Tucson Water’s future Potable Reuse Project through water quality testing and treatment process performance monitoring

• Secondary Goals:1. Test the viability of short-term SAT as a pretreatment approach to NF2. Test ozone for oxidation of CECs3. Determine GAC regeneration requirements 4. Test the viability of using NF concentrate for crop irrigation

• Operation6-months total; two three month phases

Pilot FacilitiesLocation: Tucson’s Sweetwater Recharge Basins Source: Monitoring Well 069B (~10 gpm)Duration: Oct 2014 – April 2015

Basin #2

Basin #1

Basin #3

Basin #4

Pilot Location

NF Trailer

Ozone Trailer

Ozone Skid GAC

NF

Water Quality TestingAgua Nueva

Effluent(Sweetwater

Recharge Basin Feed)

Post-SAT Effluent(Shallow

Monitoring Well)

NF Feed (after

Cartridge Filtration)

NF Permeate NF Concentrate

Ozone Effluent

BAC1 Calgon Effluent

(Phase I and II)

BAC2 Norit Effluent

(Phase I and II)

BAC3 Calgon Effluent

(Phase II only)

BAC4 Norit Effluent

(Phase II only)

Sample Designation S1 S2 S3 S4 S5 S6 S7 S8 S9 S10Tucson Water Designation 510 Well WR-069B n/a n/a n/a n/a n/a n/a n/a n/apH Field Daily DailyTemperature Field DailyConductivity Field Daily Daily DailySDI Field 3x/week 3x/weekOzone Residual Field WeeklyTurbidity Field WeeklyTSS TW Weekly BiweeklyAlkalinity TW Monthly** Weekly Weekly BiweeklyTDS TW Monthly** Weekly Weekly BiweeklyTOC TW Biweekly** Weekly Weekly Weekly Weekly Weekly Weekly WeeklyTotal Nitrogen TW Monthly** Biweekly Biweekly BiweeklyTotal Phosphorus TW Monthly** Biweekly Biweekly BiweeklyBromide TW Biweekly Biweekly BiweeklyCalcium TW Biweekly Biweekly BiweeklyMagnesium TW Biweekly Biweekly BiweeklySodium TW Biweekly Biweekly BiweeklySulfate TW Biweekly Biweekly BiweeklyChloride TW Biweekly Biweekly BiweeklyBoron TW Biweekly Biweekly BiweeklySilica TW Biweekly Biweekly BiweeklyBarium TW BiweeklyStrontium TW BiweeklyUVT-254 UA Weekly Weekly Weekly Weekly Weekly Weekly WeeklyBromate UA Monthly Monthly Biweekly Biweekly Biweekly Biweekly BiweeklyCECs UA Monthly Biweekly Biweekly Biweekly Biweekly Biweekly Biweekly BiweeklyEEM UA Monthly Biweekly Biweekly Biweekly Biweekly Biweekly Biweekly BiweeklyNDMA UA Monthly Biweekly Biweekly Biweekly Biweekly BiweeklyHeterotrophic Plate Counts (5-day) TW Biweekly Biweekly Biweekly Biweekly Biweekly BiweeklyTotal Coliform TW Monthly Monthly Monthly MonthlyE. Coli TW Monthly Monthly Monthly MonthlyEnteric Virus UA Monthly*** Monthly*** Monthly***Crypto / Giardia UA Monthly*** Monthly*** Monthly***

Sample Location and FrequencyParameter Lab

• Field Parameters• Metals, Salts, Nutrients• Trace Organics (CECs)• Nitrosamines & Bromate• Pathogens/Microorganisms

TOC Detection Limit

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

TOC

(mg/

L)

8.69 mg/L

Total Organic Carbon (50th percentile)

Agua Nueva WRF Secondary

Effluent

SOIL AQUIFER TREATMENTORGANICS

CECsPATHOGENS

SOLIDS

NF CONC.

O3

OZONATION / BAC- GAC PATHOGENSORGANICS

CECs

CL2

POTABLE WATER TO

DISTRIBUTION

SIDE STREAM NFTDS

ORGANICSPATHOGENS

CECs

FREE CHLORINE PATHOGENS

CARTRIDGE FILTER

60%Q

40%Q

91% Reductionafter SAT

45% Reduction

after Partial NF >40% Reductionafter BAC

12

TOC Detection Limit

Phase 1 Phase 20.00

0.10

0.20

0.30

0.40

0.50

0 5,000 10,000 15,000 20,000 25,000 30,000

TOC

(mg/

L)

Bed Volumes

TOC vs. S7: BAC 1 Effluent (Calgon - P1 & 2) Bed Volumes

TOC Detection Limit

Phase 1 Phase 20.00

0.10

0.20

0.30

0.40

0.50

0 5,000 10,000 15,000 20,000 25,000 30,000TO

C (m

g/L)

Bed Volumes

TOC vs. S8: BAC2 Effluent (Norit - P1 & 2) Bed Volumes

No breakthrough for Calgon BAC after 6 months

Breakthrough observed for Norit BAC

Total Organic Carbon versus Filtration Bed Volumes

0

100

200

300

400

500

600

700

800

S1: ANWRFEffluent

S2: Post-SATEffluent

S4: NFPermeate

S6: OzoneEffluent

TDS

(mg/

L)

Secondary MCL for TDS = 500 mg/L

Agua Nueva WRF Secondary

Effluent

SOIL AQUIFER TREATMENTORGANICS

CECsPATHOGENS

SOLIDS

NF CONC.

O3

OZONATION / BAC- GAC PATHOGENSORGANICS

CECs

CL2

POTABLE WATER TO

DISTRIBUTION

SIDE STREAM NFTDS

ORGANICSPATHOGENS

CECs

FREE CHLORINE PATHOGENS

CARTRIDGE FILTER

60%Q

40%QTotal Dissolved Solids (50th percentile)

• 44 CECs monitored – All below the detection limit in finished water• Some CECs are recalcitrant to certain treatment, so multiple barriers is

important

Chemicals of Emerging Concern

2015/04/30 Concentration of Trace Organics in ng/LCompounds Category Agua

NuevaEffluent

Well 69B O zoneInfluent

O zoneEffluent

BAC C1(Calgon) Effluent

BAC C2(Calgon) Effluent

BAC C3(Norit)

Effluent

BAC C4(Norit)

EffluentBenzophenone Industry (paint,

129 < 30 < 16 < 30 < 28 < 29 < 30 < 29

Benzotriazole De-icing, inhibitor,

4236 4755 4051 2416 < 480 < 480 < 470 < 500

Caffeine stimulant < 4.0 < 5.2 < 4.4 < 5.6 < 3.9 < 4.1 < 3.7 < 3.8Carbamezapine Anit-epileptic 363 487 126 < 1.6 < 1.6 < 1.5 < 1.5 < 1.5DEET Insect repellant 172 7.0 14 < 6.0 < 4.1 < 4.0 < 3.8 < 3.6Gemfibrozil cholesterol drug 5.4 < 1.0 < 1.0 < 1.1 < 0.9 < 0.9 < 0.9 < 0.9Ibuprofen anti-inflamatory, < 2.8 < 3.7 < 3.5 < 4.9 < 3.6 < 3.5 < 3.0 < 3.5Iopamidol Angiography 29677 3188 913 1395 < 27 < 28 < 26 < 31Iopromide x-ray contrast 5465 < 24 < 34 < 24 < 27 < 28 < 26 < 31Meprobamate tranquilizer 455 58 28 29 < 10 < 10 < 10 < 10PFO A cookware,

textiles, clothing, 2.2 32.3 16.3 15.8 < 0.8 < 0.8 < 0.7 < 0.7

PFO S Stain repellant < 6.3 256 124 123 < 3.5 < 3.5 < 3.8 < 3.9Primidone Anit-epileptic 14 165 90 87 < 4.3 < 5.7 < 4.8 < 4.8Sucralose Artifical sweetner 51567 26702 7595 13459 < 220 < 240 < 240 < 250Sulfamethoxazole antibiotic 1903 36 15 < 8.0 < 5.0 < 4.9 < 4.5 < 4.9TCEP Flame retardant 128 181 31 125 < 22 < 22 < 23 < 23TCPP Flame retardant 715 < 24 129 83 < 22 < 22 < 23 < 23Triclosan soap 44 < 12 < 9 < 13 < 13 < 14 < 13 < 14

Trace Organics RemovalExcitation Emission Matrix Results

WWTP Secondary

Effluent

SOIL AQUIFER TREATMENT

NF CONC.

O3

NANOFILTRATION

CARTRIDGE FILTER

60%Q

40%Q

OZONATION BAC/GAC

Blank: Milli-Q WaterLegend

Bromate & NDMA

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0

10

20

30

40

50

60

70

Ozo

ne D

ose

(mg/

L)

Bro

mat

e Co

ncen

tratio

n (μg/L)

Ozone Inf Ozone Eff

BAC Inf BAC Calgon (P1)

BAC Calgon (P2) BAC Norit (P1)

BAC Norit (P2) Target

Ozone Dose• Bromate and NDMA are disinfection byproducts from ozone addition

• Bromate formation:– Significant at O3 doses

> 0.5 mg/L (O3:TOC ratio > 1.0)

– Low at O3 doses < 0.5 mg/L (O3:TOC <1.0)

• NDMA Formation:– Very high in the WWTP

secondary effluent– Excellent removal by

SAT (< 10 ng/L)– Small production by

ozone, but subsequent removal by BAC

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

2014/09/18 2014/11/07 2014/12/27 2015/02/15 2015/04/06 2015/05/26

NDM

A (n

g/L)

NDMA

WWTP Effluent Post SAT BAC Influent BAC Effluent

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

2014/09/18 2014/11/07 2014/12/27 2015/02/15 2015/04/06 2015/05/26

NDM

A (n

g/L)

NDMA

WWTP Effluent Post SAT BAC Influent BAC Effluent

Bromate & NDMA

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0

10

20

30

40

50

60

70

Ozo

ne D

ose

(mg/

L)

Bro

mat

e Co

ncen

tratio

n (μg/L)

Ozone Inf Ozone Eff

BAC Inf BAC Calgon (P1)

BAC Calgon (P2) BAC Norit (P1)

BAC Norit (P2) Target

Ozone Dose• Bromate and NDMA are disinfection byproducts from ozone addition

• Bromate formation:– Significant at O3 doses

> 0.5 mg/L (O3:TOC ratio > 1.0)

– Low at O3 doses < 0.5 mg/L (O3:TOC <1.0)

• NDMA Formation:– Very high in the WWTP

secondary effluent– Excellent removal by

SAT (< 10 ng/L)– Small production by

ozone, but subsequent removal by BAC

0.0

0.2

0.4

0.6

0.8

1.0

1.2

OzoneInfluent

OzoneEffluent

BACInfluent

BAC #2(Calgon)Effluent

BAC #4(Norit)

Effluent

NDM

A (n

g/L)

NDMA through Advanced Water Treatment Process

* Below Detection Limit (< 0.5 ng/L )

* **

Pathogens

-1

0

1

2

3

4

5

6

7

Adenovirus PMMoV Aichi Enterovirus

Log

Conc

entr

atio

n (lo

g/L)

Virus Removal by Soil Aquifer Treatment

WWTP Effluent Post SAT

ND ND NDND

• PCR Method Used• Concentration represent

physical presence of viruses (live or dead), not infectivity

• > 4-log removal achieved through SAT

Conclusions

19

Issue AnswerDo multiple organics barriers provide suitable water quality?

Yes; finished water quality:1) TOC< 0.25 mg/L2) All 44 CECs non-detect

Can TDS goal be met with sidestreamNF treatment?

Yes, TDS < 500 mg/L consistently met

Can bromate and NMDA formation be controlled?

Yes, both were well below regulated limits:

Bromate < 3 µg/L (MCL = 10 µg/L)NDMA < 0.5 ng/L (CA limit 10 ng/L)

Are pathogens adequately removed? Yes, post-SAT water was non-detect for viruses and protozoa; >4-log removal of viruses by just SAT

Is GAC-based train suitable for potable reuse at Tucson?

Yes and costs are much lower than RO-based train

• Final Report for WRRF13-09 will be published in 2015 / 2016

Acknowledgements

Team Member RoleJustin Mattingly, WRRF WRRF Project ManagerLarry Schimmoller, CH2M HILL Principal InvestigatorDr. Shane Snyder, UA Co-PI; Water Quality, Ozone and BAC/GAC Pilot OperationsDr. Wendell Ela, UA Co-PI; NF Pilot Operations, Membrane AutopsyDr. Bob Arnold, UA Proxy for Wendell ElaMichael Hwang, CH2M HILL Project EngineerJim Lozier, CH2M HILL Membrane ExpertJeff Biggs, TW Tucson Water Project ManagerBruce Prior, TW HydrogeologistTerry Miley, TW HydrogeologistTucson Water Quality Laboratory Water Quality AnalysisDan Candelaria, CH2M HILL Pilot Construction and Operation SupportTarun Anumol, UA Lead Ozone and BAC/GAC Operations; WQ TestingJosh Campbell, UA NF Pilot Operations, Membrane Autopsy

CH2M HILL gratefully acknowledges the WateReuse Research Foundation’s financial, technical, and administrative assistance in funding and managing the project through which

this information was discovered

Questions?

21