WQ Monitoring During Full- Scale Seawater Desalination Operations

Transcription

1 American Water Works Association 2007 WQTC WQ Monitoring During Full- Scale Seawater Desalination Operations Tai J. Tseng, Robert C. Cheng, and Kevin L. Wattier Long Beach Water Department November 6, 2007

2 Presentation Outline Long Beach Overview Water Quality Monitoring Source Water Monitoring Prototype WQ Performance Monitoring NPDES Monitoring Conclusion 2007 WQTC LBWD 2

3 Presentation Outline Long Beach Overview Water Quality Monitoring Source Water Monitoring Prototype WQ Performance Monitoring NPDES Monitoring Conclusion 2007 WQTC LBWD 3

4 Long Beach Water Department California s 5th most populous city (~500,000 people) 70,000 AF of drinking water per year 8,000 AF of reclaimed water per year Operate largest GW treatment plant in US 912 miles of drinking water lines 763 miles of sewer lines 2007 WQTC LBWD 4

5 Imported Water Supply California Aqueduct: >30% Reduction Colorado River Aqueduct: ~reduction Los Angeles Aqueduct: ~reduction communities must produce more water locallyll to manage new limits on imports and growth in southern California s i population and economy WQTC LBWD 5

6 Future Reliability Very little population growth Expansion of recycled water and water conservation Seawater supplement desalination ==> City s imported necessary drinking water supply 2007 WQTC LBWD 6

7 LBWD s Resource Mix Conservation 14% Reclaimed 6% Conservation 15% Groundwater Groundwater 33% Reclaimed 38% 12% Imports 42% Imports 30% Desal 10% 2007 WQTC LBWD 7

8 Prototype Construction 2007 WQTC LBWD 8

9 Prototype Processes NPDES Monitoring Combined Effluent Tanks Energy Recovery Backwash water Influent Tank Cartridge Filter Energy Recovery 1 st Pass NF 2 nd Pass NF MF Cartridge Filter RO Source Monitoring Performance Monitoring 2007 WQTC LBWD 9

10 Presentation Outline Long Beach Overview Water Quality Monitoring Source Water Monitoring Prototype WQ Performance Monitoring NPDES Monitoring Conclusion 2007 WQTC LBWD 10

11 Source Water Monitoring GP ICs VOCs SOCs Turbidity Antimony 1,1,1-Tirichloroethane 1,2-diphenylhydrazine Benzo(k) fluoranthene Total Suspended Solids Arsenic 1,1,2,2-Tetrachloroethane 1,3-dichlorobenzene Beta-BHC Oil and Grease Beryllium 1,1,2-Trichloroethane 2,4,6-trichlorophenol Beta-endosulfan BOD5 20oC Cadmium 1,3-Dichlorobenzene (1,3-DCB) 2,4-dichlorophenol Bis(2-chloroethoxy) methane MBAS Chromium-III 1,4-Dichlorobenzene (1,4-DCB) 2,4-dimethylphenol Bis(2-chloroethyl) ether Settleable Solids Chromium-VI 1,1-Dichloroethane 2,4-dinitrophenol Bis(2-chloroisopropyl) ether Sulfides Copper 1,1-Dichoroethene (1,1-DCE) 2,4-dinitrotoluene Butyl benzyl phthalate Ammonia as N Cyanide 1,2,4-Trichlorobenzene 2,6-dinitrotoluene Chlordane Lead 1,2-Dichlorobenzene (1,2-DCB) 2-chloronaphthalene Chrysene Mercury 12Di 1,2-Dichloroethane (12DCA) (1,2-DCA) 2-chlorophenol h l Delta-BHC Nickel 1,2-Dichloropropane 2-Methyl-4,6-Dinotrophenol Dieldrin Selenium 1,3-Dichloropropene (total) 2-nitrophenol Diethyl phthalate Basically, Silver 2-chloroethyl everything vinyl ether 3,3'-dichlorobenzidine Dimethyl phthalate Thallium Acrolein 3-Methyl-4-Chlorophenol Di-n-butyl phthalate Zinc Acrylonitrile 4,4'-DDD Di-n-octyl phthalate Total Hardness (as CaCO3) Benzene 4,4'-DDE Endosulfan sulfate Asbestos Bromodichoromethane 4,4'-DDT Endrin Bromoform 4-bromophenyl phenyl ether Endrin aldehyde Carbon Tetrachloride (CTC) 4-chlorophenyl phenyl ether Fluoranthene Chlorobenzene 4-nitrophenol Fluorene Chloroethane Acenaphthene Heptachlor Chloroform Acenaphthylene Heptachlor Epoxide Dibromochloromethane Aldrin Hexachlorobenzene Dibromomethane Alpha-BHC Hexachlorobutadiene Dichloromethane (DCM) Alpha-endosulfan Hexachlorocyclopentadiene Ethylbenzene Anthracene Hexachloroethane Methyl Bromide(Bromomethane) Benzidine Indeno(1,2,3-cd) pyrene Tetrachloroethylene (PCE) Benzo(a) anthracene Isophorone Toluene Benzo(a)pyrene Lindane (Gamma BHC) trans-1,2-dichloroethylene Benzo(b) fluoranthene Napththalene Trichloroethylene (TCE) Polychlorinated Biphenyls Nitrobenzene Vinyl Chloride Pyrene n-nitrosodimethylamine (NDMA) Toxaphene N-nitrosodi-n-propylamine Tertiary butyl alcohol N-nitrosodiphenylamine Methyl tert butyl ether Pentachlorophenol Phenanthrene 1,12-benzoperylene Phenol 1,2,5,6-dibenzanthracene 2,3,7,8-TCDD (Dioxin) Bis (2-ethylhexyl) phthalate y, y g 2007 WQTC LBWD 11

12 Source Water Monitoring What did we find? Not a whole lot of generally monitored constituents What s important? t? Low turbidity Mostly NDs Good source water WQTC LBWD 12

13 Source Water Monitoring Marine Biotoxins toxins produced by certain species of marine algae. Domoic acid was identified in 1991 as the cause of a major bird dieoff in the Monterey region. Although h many shellfish h and filter feeder fish can bio-accumulate Domoic Acid without signs of poisoning, birds and mammals that feed on affected shellfish and fish can lead to Amnesic Shellfish Poisoning WQTC LBWD 13

14 Source Water Monitoring Diatom bloom was heavy this spring off the coast of Long Beach. Source water monitoring was established with USC to investigate the potential impacts to desalination 2007 WQTC LBWD 14

15 Source Water Monitoring Domoic Acid was not found by the time sampling began, thus, levels of removal could not be determined. Continue monthly unless an algal bloom is detected. Monitoring would then increase to weekly. Noteworthy to point out that this is just monitoring. Location Date Detection Description 5/24/2007 5/31/2007 6/7/2007 6/14/2007 July-07 Limit Units Raw (Total) ND ND ND ND ND 0.01 ng/ml Raw (Dissolved) ND ND ND ND ND ng/ml MF Permeate ND ND ND ND ND 0.01 ng/ml NF Feed ND ND ND ND ND 0.01 ng/ml NF Permeate ND ND ND ND ND 0.01 ng/ml RO Feed ND ND ND ND ND 0.01 ng/ml RO Permeate ND ND ND ND ND 0.01 ng/ml 2007 WQTC LBWD 15

16 Presentation Outline Long Beach Overview Water Quality Monitoring Source Water Monitoring Prototype WQ Performance Monitoring NPDES Monitoring Conclusion 2007 WQTC LBWD 16

17 Prototype Monitoring Analysis Units Raw Water NF Tests SWRO Tests Bromide mg/l Chloride mg/l Fluoride mg/l ND ND ND ND ND ND ND ND ND Nitrate-N mg/l 1.05 ND ND ND ND ND ND ND ND Phosphate mg/l ND ND ND ND ND ND ND ND ND Sulfate mg/l 2582 ND 10.5 ND ND ND ND ND ND Ammonia-N mg/l ND ND ND ND ND ND ND ND ND Calcium mg/l 441 ND ND ND ND ND Lithium mg/l ND ND ND ND ND ND ND ND ND Magnesium mg/l 1209 ND ND ND ND ND Potassium mg/l Sodium mg/l Boron mg/l Conductivity umhos/cm ph ph Units TDS mg/l WQTC LBWD 17

18 Presentation Outline Long Beach Overview Water Quality Monitoring Source Water Monitoring Prototype WQ Performance Monitoring NPDES Monitoring Conclusion 2007 WQTC LBWD 18

19 Prototype yp Location 2007 WQTC LBWD 19

20 NPDES Monitoring Monitoring Requirements Due to site location, discharge must meet the requirements for Toxic Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California for priority pollutants. Dilution credits are not allowed as the receiving water is already classified as impaired. Thus, we could not get credit for co-mingling with power plant effluent WQTC LBWD 20

21 NPDES Monitoring Monitoring Requirements Daily monitoring of FLOW, ph and TEMPERATURE. Monthly Monitoring for General Physicals (6 parameters). Quarterly monitoring of priority pollutants (8 Metal Parameters and 113 Organic Parameters) Annual monitoring for MTBE, TBA, and acute toxicity. Discharge monitoring becomes a very large program to manage 2007 WQTC LBWD 21

22 NPDES Monitoring Discharge Limits (partial list of key items). Constituent/ Parameters (Drinking Water MCL) Monthly Ave. Daily Max. Units Turbidity NTU TSS mg/l Arsenic µg/l Chromium-VI 50 - µg/l Copper (1300) µg/l Lead µg/l Mercury µg/l Nickel µg/l Selenium µg/l Zinc µg/l VOCs SOCs Don't find any or "NOT GOOD" 2007 WQTC LBWD 22

23 NPDES Monitoring Our first quarter monitoring results yielded.. Constituent/ Parameters Intake Effluent Units General Physical ND ND Chromium µg/l Copper µg/l Lead µg/l Nickel µg/l VOCs ND ND SOCs ND ND Everything was good except for Cu. Although Cr & Ni were below the limits, the significant lead to further investigations WQTC LBWD 23

24 NPDES Monitoring Found a copper plug in one of the pump p drains. Mass differential was grams. Average influent Cu is around 2.8 μg/l. Monthly Max 3.1 μg/l. Mass loss was 14,850,000 μg. Doesn t take a whole lot to push you over!!! g g 2007 WQTC LBWD 24

25 NPDES Monitoring Cr & Ni are key components to stainless steel. Found corrosion in our 304, 316 and Super Duplex Stainless Steel. Change to plastic where possible. Change to more compatible metals (galvanic scale) where possible WQTC LBWD 25

26 NPDES Monitoring Most recent monitoring shows significant reduction in rate of corrosion and compliance problems associated with the corrosion. Constituent/ Parameters Intake Effluent Units General Physical ND ND Chromium-III ND 2.3 µg/l Copper µg/l Lead ND ND µg/l Nickel µg/l VOCs ND ND SOCs ND ND 2007 WQTC LBWD 26

27 Presentation Outline Long Beach Overview Water Quality Monitoring Source Water Monitoring Prototype WQ Performance Monitoring NPDES Monitoring Conclusion 2007 WQTC LBWD 27

28 Conclusions Source water monitoring suggests seawater quality does not pose traditional water quality challenges. Marine biotoxin, specifically Domoic Acid, was not found by the time sampling began. Monitoring will continue monthly and if Domoic Acid is detected, monitoring will increase to weekly. Plant operations show that NF/NF process produces similar waters as traditional SWRO. Boron is poorly rejected but with intermediate ph adjustment, boron rejection is better than SWRO WQTC LBWD 28

29 Conclusions NPDES permit monitoring is a substantial undertaking, involving schedules, budgets, and people-hours, and should be well planned ahead. NDPES monitoring actually helped us locate and identify material problems. If your source water is out of compliance, you ARE out of compliance. Depending on your receiving i waters, you may not be allowed dilution credits WQTC LBWD 29

30 Questions Call Cynthia (800) WQTC LBWD 30