Your Water – Locally Produced!

Jason M. Brabec, P.E.

Innovative Recycled Water Desalination for the Cache Creek Casino Resort

HYDROSCIENCE ENGINEERS INC.

WateReuse California Annual Section Conference 2010

Background

PROJECT LOCATION

Cache Creek Casino ResortBrooks, California

WASTEWATER EFFLUENT QUALITY

Recycled water meets Title 22 Criteria (Unrestricted Use)

PARAMETER EFFLUENT AVERAGE

Flow 230,000 gpd

Peak Treatment Capacity 475,000 gpd

Chlorine Residual 1-5 mg/L

Turbidity 0.10 NTU

RECYCLED WATER DISTRIBUTION

• Toilet flushing within the Resort• Decorative water features• Landscape site irrigation• Yocha Dehe Golf Course irrigation

SITE WATER CYCLE

1.1 MG

WELLS

RW

RESORT / FACILITIES

WWTP

18

GOLFCOURSE

WATER FEATURES

CACHE CREEK

LANDSCAPEIRRIGATION

Water Quality Impacts

SOURCE GROUNDWATER

• Elevated levels of TDS• High hardness

ION EXCHANGE SOFTENER

1.1 MG

WELLS

RW

RESORT / FACILITIES

WWTP

18

GOLFCOURSE

WATER FEATURES

CACHE CREEK

LANDSCAPEIRRIGATION

WATERSOFTENERS

NaCl

RECYCLED WATER QUALITY IMPACTS

Significantly Impacted Recycled Water Effluent Quality

WATER SOURCES TDSmg/L

Sodiummg/L

Chloridemg/L

Hardnessgrains

Groundwater (source water) 539 81 113 17.5

Potable water supply after ion-exchange 717 183 107 0-1

Recycled water effluent 1,582 491 630 NA

IMPACTS OF HIGH SALTS

• Reduced irrigation suitability• Significant dilution required to comply with WDR

discharge limits• Increased maintenance of toilet flushing valves• Aesthetic issues

Development of Solutions

GOALS & OBJECTIVES

• Provide soft water• Suitable recycled water quality for irrigation

purposes• Comply with WDR• Minimize distribution system maintenance• Maximize water reuse• Maintain environmental stewardship

BRINE DISPOSAL

• Ocean discharge• Deep well injection• Discharge to other municipality• Crystalizer

• Off-haul for disposal

ALTERNATIVES

A) Off haul ion-exchange regeneration brineB) Desalinate recycled waterC) Desalinate potable water

ALTERNATIVE A

1.1 MG

WELLS

RW

RESORT / FACILITIES

WWTP

18

GOLFCOURSE

WATER FEATURES

CACHE CREEK

LANDSCAPEIRRIGATION

WATERSOFTENERS

NaCl

OFF-HAULBRINE DISPOSAL

ALTERNATIVE B

1.1 MG

WELLS

RW

RESORT / FACILITIES

WWTP

18

GOLFCOURSE

WATER FEATURES

CACHE CREEK

LANDSCAPEIRRIGATION

WATERSOFTENERS

NaCl

DESALINATIONBRINE

DISPOSAL

ALTERNATIVE C

1.1 MG

WELLS

RW

RESORT / FACILITIES

WWTP

18

GOLFCOURSE

WATER FEATURES

CACHE CREEK

LANDSCAPEIRRIGATION

OFF-HAULBRINE DISPOSAL

POTABLEWATERDESALINATION

WATERSOFTENERS

NaCl

THE WINNER!

OTHER DESIGN CONSIDERATIONS

• Site constraints – topography

• Out of sight from patrons

• Two-step brine concentrationprocess(due to brine off-haul)

Water Desalination Treatment Facility

FIRST STEP: DESAL AND SOFTENING

• Elevated silica levels in source ground water• High recovery rates

ElectrodialysisReversal (EDR)Selected

EDR TECHNOLOGY

Cl_

Na+

Na+

Cl _

Cl_

Cl_

Na+

ANODE (+)FEED PRODUCT

BLOWDOWN(WASTE)

CATHODE (-)

Cl_

Cl_

Na+

Na+

CONCENTRATEMAKEUP

CONCENTRATERECYCLE

RECYCLE PUMP

C

A

C

A

C

A

C

SOU

RC

E: G

E

SECOND STEP: BRINE CONCENTRATION

• Clarifier and pH conditioning• Elevated silica levels in EDR reject• Piloted Vibratory Shear Enhanced

Process (VSEP) system

VSEP selected for 2nd stage

VSEP TECHNOLOGY

SOU

RC

E: N

EW L

OG

IC R

ESEA

RCH

EDR TREATMENT PROCESS

EDR PUMPS BLEND TANK AND TREATMENT TRAINS

VSEP FEED TANK VSEP FILTER PACKS

VSEP TREATMENT PROCESS

BRINECONCENTRATION

CHEMICAL HANDLING FACILITY

CHEMICAL LOADING AREACHEMICALS

WDTF DESIGN CAPACITY

Parameter Capacity DescriptionAvg. Daily Softening Production Capacity 650,000 GPD Finished Water

(< 3 grain hardness)

Reject Concentration 125,000 GPD Reject Treatment

Brine Generation 20,000 GPD Brine Concentrate

Building 8,500 sq-ft Process area, lab, chemical room, MCC

RECYCLED WATER QUALITY IMPACTS

Water Source TDS(mg/L)

Sodium(mg/L)

Chloride(mg/L)

Groundwater (Source Water) 539 81 113

Potable Water (EDR Finish Water) 195 39 53

Recycled Water Effluent 545 (1,582) 146 (491) 159 (630)

Percent Reduction (2007 vs 2009) 66% 70% 75%

WDTF RECOVERY RATE

System PercentRecovery

Electrodialysis Reversal System 85%

VSEP System 85%

Water Desalination Treatment Facility 97%

POTENTIAL IMPROVEMENTS

• Increase recovery of EDR• Evaluate waste streams• Conditioning of VSEP feed

Conclusion

GOALS & OBJECTIVES - Revisited

Provide soft water Suitable recycled water for irrigationComply with WDRMinimize distribution system maintenanceMaximize water reuseEnvironmental stewardship

Jason M. Brabec, P.E.10569 Old Placerville Road

Sacramento, CA 95827916-364-1490

jbrabec@hydroscience.com

HydroScience Engineers