Regional Water Quality Issues: Algae and Associated Drinking Water Challenges. Workshop October 2008

Transcription

1 Regional Water Quality Issues: Algae and Associated Drinking Water Challenges Workshop October 28 A Cooperative Research and Implementation Program Arizona State University (Tempe, AZ) Paul Westerhoff, Chao-An Chiu, Jun Wang, Pierre Herckes, Rolf Halden, and Marisa Masles Salt River Project Central Arizona Project City of Phoenix City of Tempe City of Peoria City of Glendale ASU NSF Water Quality Center 1 YEAR Anniversary Developing a Taste and Odor Control Program for the City of Phoenix Collaborators: Arizona State University City of Phoenix Salt River Project Central Arizona Project Larry Baker, Paul Westerhoff and Milt Sommerfeld Arizona State University 1

2 Agenda Purpose: Provide a forum to review and discuss on-going regional water quality issues, in particular algae-associated issues. 8:3 Refreshments 8:45 Introductions 9: Project scope & goals 9:15 Overview of water quality trends for Taste and Odor Compounds & other key water quality that affects drinking water 9:35 Understanding "where our turbidity comes from" Break 1: Pharmaceutical occurrence in source waters 1:2 Characterization of NOM & DBP formation 1:4 Removal of NOM from different source waters by Granular Activated Carbon 11: Future directions & discussion Project Goals Collect consistent database for non-regulated water constituents in central Arizona drinking water systems that cross jurisdictional boundaries Conduct research that improves our understanding of algal activity and hydrologic conditions on taste and odor production and organic matter Communicate watershed-wide water quality data and disseminate information on water quality/treatment to aid the local water systems Leverage funding from multiple local cities and agencies for water quality and treatment research projects 2

3 Focus for 28 Continued monitoring of course Endocrine disruptor, pharmaceuticals & personal care product occurrence Organic matter characterization Ability to remove organic matter & DBP precursors by granular activated carbon Analysis of sources of turbidity in our waters Long-Term Database Is Becoming a Powerful Tool Routing monitoring at fixed sites Special Experiments (e.g. PAC screening) Access Database Synoptic Sampling Queries for graphs & data analysis 3

4 Benefits Leveraged the funding with at least 8:1 external funding. Recent projects include: AwwaRF / MPI/ ASU ($165K) implant algae control AwwaRF/ MWD/ASU /Yale ($45K) N-DBPs AwwaRF / ASU Organic chloramines ($15K) WERF / ASU organic colloids ($1K) SRP / ASU DBP Project + Molecular Probes + EDC occurrence ($15K) Provides visibility to outside world that water municipalities in central Arizona are progressive and working collectively to understand and improve water quality Development of analytical and experimental skills to assist cities/consultants on regional issues ASU maintains ability to serve as independent third party for PAC testing We provide donuts and bagels at meetings Overview of Water Quality in 28 relative to other years 4

5 Sampling Locations Project is spanning dry-wet years Salt River Above Roosevelt Flow (cfs) J-1 J-2 J-3 J-4 J-5 J-6 D-69 D-79 D-89 D-99 D-9 5

6 Hydrology Affects Water Quality (conductance can affect algal dominance) Conductivity (μs/cm) Lake Pleasant Bartlett Lake Saguaro Lake Jul-99 Jul- Jul-1 Jul-2 Jul-3 Jul-4 Jul-5 Jul-6 Jul-7 Jul-8 Thermal stratification of lakes affect water quality released from them (Lake Pleasant) 1 Temperature (C) Depth (m) /1/27 1/8/27 11/12/27 12/3/27 2/4/28 3/3/28 5/5/28 7/7/28 8/4/28 6

7 Saguaro Lake is only weakly stratified Temperature ( C) Depth from surface (m) /8/27 1/7/28 2/4/28 3/3/28 4/7/28 5/6/28 6/3/28 7/9/28 8/4/28 1/7/28 Bartlett Lake Temperature ( C) Depth from surface (m) /1/27 8/6/27 9/11/27 1/8/27 11/12/27 2/4/28 3/3/28 4/7/28 5/6/28 6/3/28 7/9/28 8/4/28 7

8 Arsenic Levels Vary in Sources and in response to climatic influences 3 25 Pleasant Hypo Bartlett Hypo Saguaro Hypo Arsenic (μg/l) Total dissolved nitrogen (mg/l) Winter Rains MCL = 1 μg/l 4/13/4 7/2/4 1/12/4 1/18/5 4/12/5 7/12/25 1/11/25 1/17/26 4/1/26 7/11/26 1/1/26 1/9/27 4/9/27 7/9/27 1/8/27 1/7/28 4/7/28 7/7/28 Dissolved Nitrogen Trends in Reservoirs Inorganic nitrogen converts to particulate algal biomass Saguaro Epi Saguaro Hypo Total dissolved nitrogen (mg/l) Total dissolved nitrogen (mg/l) Pleasant Epi Pleasant Hypo Dec-6 Aug-99 Aug- Aug-1 Aug-2 Aug-3 Aug-4 Aug-5 Aug-6 Aug-7 Aug-8 Saguaro Epi Saguaro Hypo Aug-99 Aug- Aug-1 Aug-2 Aug-3 Aug-4 Aug-5 Aug-6 Aug-7 Aug-8 Total dissolved nitrogen (mg/l) Jun Bartlett Epi Bartlett Hypo Aug-99 Aug- Dec-7 Aug-1 Aug-2 Aug-3 Aug-4 Jun-8 Aug-5 Aug-6 Aug-7 Aug-8 8

9 Total Phosphorous 1 Pleasant Epi Total phosphrous (μg/l) Jun-99 Dec-99 Jun- Dec- Saguaro Epi Saguaro Hypo Jun-1 Dec-1 Jun-2 Dec-2 Jun-3 Dec-3 Jun-4 Dec-4 Jun-5 Dec-5 Jun-6 Dec-6 Jun-7 Dec-7 Jun-8 Total phosphrous (μg/l) Jun-99 Dec-99 Jun- Pleasant Hypo Dec- Jun-1 Dec-1 Jun-2 Dec-2 Jun-3 Dec-3 Jun-4 Dec-4 Jun-5 Dec-5 Jun-6 Total phosphrous (μg/l) Dec-6 Jun Dec-7 Jun-8 Jun-99 Dec-99 Jun- Dec- Bartlett Epi Bartlett Hypo Jun-1 Dec-1 Jun-2 Dec-2 Jun-3 Dec-3 Jun-4 Dec-4 Jun-5 Dec-5 Jun-6 Dec-6 Jun-7 Dec-7 Jun-8 Up-stream reservoirs attenuate DOC DOC (mg/l) Lake Pleasant Bartlett Lake Saguaro Lake 8/1/ 6/1/1 4/1/2 11/13/2 7/14/3 3/16/4 2/15/5 12/6/25 1/11/26 8/6/27 6/2/28 Saguaro Lake DOC increasing by.37 mg/l per year 9

10 Specific UV Absorbance at 254 nm SUVA = UVA / DOC 8 SUVA (L/m/mg) /1/1999 2/1/2 8/1/2 Pleasant Bartlett Saguaro 2/1/21 8/1/21 2/1/22 8/1/22 2/1/23 8/1/23 2/1/24 8/1/24 2/1/25 8/1/25 2/1/26 8/1/26 2/1/27 8/1/27 2/1/28 8/1/28 Avg DOC (mg/l) DOC Removal by WTP Influent (25) Influent (26) Effluent (25) Effluent (26) Influent (27) Influent (28) Effluent (27) Effluent (28) 24th Street WTP DV WTP VV WTP Green WTP NP WTP SPT WTP UH WTP DOC % removal has increased over time 1

11 Secchi Disk Depth Influenced by Inorganic Suspended Sediment and/or Organic Biomass Secchi Disk Depth (m) Jan-2 May-2 Oct-2 Feb-3 Jul-3 Dec-3 Apr-4 Sep-4 Jan-5 Jun-5 Nov-5 Mar-6 Aug-6 Dec-6 May-7 Oct-7 Feb-8 Jul-8 Lake Pleasant Bartlett Lake Saguaro Lake Nov-8 11

12 Geosmin Data Geosmin (ng/l) Jun-99 Lake Pleasant Eplimnion Lake Pleasant Hypolimnion Jun- Jun-1 Jun-2 Jun-3 Jun-4 Jun-5 Jun-6 Jun-7 Jun-8 Huge Geosmin peaks in 27 pre- April & midsummer only in upper part of water column Geosmin (ng/l) Aug-99 Feb- Aug- Bartlett Lake Eplimnion Bartlett Lake Hypolimnion Feb-1 Aug-1 Feb-2 Aug-2 Feb-3 Aug-3 Feb-4 Aug-4 Feb-5 Aug-5 Feb-6 Aug-6 Feb-7 Aug-7 Feb-8 Aug-8 Geosmin (ng/l) Aug-99 Feb- Aug- Saguaro Lake Eplimnion Saguaro Lake Hypolimnion Feb-1 Aug-1 Feb-2 Aug-2 Feb-3 Aug-3 Feb-4 Aug-4 Feb-5 Aug-5 Feb-6 Aug-6 Feb-7 Aug-7 Feb-8 Aug-8 MIB Data Lake Pleasant 1 8 Lake Pleasant Eplimnion (R2A) MIB (ng/l) Aug-99 Feb- Aug- Feb-1 Aug-1 Feb-2 Aug-2 Feb-3 Aug-3 Feb-4 Aug-4 Feb-5 Aug-5 Feb-6 Aug-6 Feb-7 Aug-7 Feb-8 MIB (ng/l) 1 Aug Lake Pleasant Hypolimnion (R2B) Aug-99 Feb- Aug- Feb-1 Aug-1 Feb-2 Aug-2 Feb-3 Aug-3 Feb-4 Aug-4 Feb-5 Aug-5 Feb-6 Aug-6 Feb-7 Aug-7 Feb-8 Aug-8 12

13 MIB Data Bartlett Lake 1 8 Bartlett Lake Eplimnion (R6A) MIB (ng/l) Aug-99 Feb- Aug- Feb-1 Aug-1 Feb-2 Aug-2 Feb-3 Aug-3 Feb-4 Aug-4 Feb-5 Aug-5 Feb-6 Aug-6 Feb-7 MIB (ng/l) Aug-7 Feb-8 Aug Aug-99 Feb- Aug- Bartlett Lake Hypolimnion (R6B) Feb-1 Aug-1 Feb-2 Aug-2 Feb-3 Aug-3 Feb-4 Aug-4 Feb-5 Aug-5 Feb-6 Aug-6 Feb-7 Aug-7 Feb-8 Aug-8 MIB Data Saguaro Lake MIB (ng/l) Saguaro Lake Eplimnion (R9A) Aug-99 Feb- Aug- Feb-1 Epi Hypo Dam Aug-1 Feb-2 Aug-2 Feb-3 Aug-3 Feb-4 Aug-4 Feb-5 Aug-5 Feb-6 Aug-6 Feb-7 Outlet Aug-8 Aug-7 Feb-8 MIB (ng/l) ng/l on 9/8/8 Saguaro Lake Hypolimnion (R9B) 135 ng/l on 9/8/8 Aug-99 Feb- Aug- Feb-1 Aug-1 Feb-2 Aug-2 Feb-3 Aug-3 Feb-4 Aug-4 Feb-5 Aug-5 Feb-6 Aug-6 Feb-7 Aug-7 Feb-8 Aug-8 13

14 Change in MIB conc. (ng/l) Aug-99 Feb- Aug- MIB Growth in Arizona canal from below X-Con to DV Inlet Very little in-canal MIB production in recent years: 1) Reduced variability in water source 2) Less GW pumping 3) Scottsdale WTP on-line 4) Suggestions to add copper to canals now would be futile Feb-1 Aug-1 Feb-2 Aug-2 Feb-3 Aug-3 Feb-4 Aug-4 Feb-5 Aug-5 Feb-6 Aug-6 Feb-7 Aug-7 Feb-8 Aug-8 MIB levels higher in Arizona Canal system compared against South Canal system 8 7 Tempe North Plant Tempe South Plant WTP Influent MIB (ng/l) Jun-2 Nov-2 Apr-3 Sep-3 Feb-4 Jul-4 Dec-4 May-5 Oct-5 Mar-6 Aug-6 Jan-7 Jun-7 Nov-7 Apr-8 Sep-8 14

15 Summary of General Water Quality & Operations Normal winter rains and above average moonsoons appear to have increased nutrient levels in some reservoirs Very high MIB production in Saguaro Lake; offset by SRP switching to Verde River in September Reservoirs are quite productive (low secchi disc = high algae) but conditions may not be favoring establishment of MIB producing algae DOC levels in Saguaro Lake have increased constantly over past 8 years (.37 mg/l/year) EL NIÑO/SOUTHERN OSCILLATION (ENSO) neutral conditions are predicted through the Northern Hemisphere into Spring 29 & normal weather conditions predicted by NOAA When it Rains Where does turbidity come from in our waters? 15

16 Turbidity Turbidity affects WTP operations (chemical dosing, solids loading & pathogen indictors) Turbidity response has been a focus for several cities in 27-8 Two turbidity events occur: long-duration events resulting from upland runoff during winter or spring; Verde River reservoirs overflow short-term events resulting from moonsoon events in the summer (focus of this study) Critical Question Where does runoff carrying turbidity originate from that enters the SRP canals? What type of early warning program could be implemented? 16

17 We focused on several major events Three sub-watersheds identified 17

18 Hydrologic Insights Added flow between on the Salt River below Stewart Mountain Dam and the confluence with the Verde River: Contribution of runoff from this sub-watershed is small compared with Sycamore Creek or Camp Creek watersheds Contribution towards turbidity was negligible Added flow between on the Verde River below Bartlett Dam and confluence with Salt River: A water balance in the Lower Verde River using USGS gauging stations can be closed Sycamore Creek produces roughly 2.5 times more runoff volume than Camp Creek watershed Less than 5% of rainfall volume in sub-watersheds actually enters the Verde River (only during higher flow events) These sub watersheds are dominate source of turbidity during rain events July 28 Event & Sampling Sycamore Creek USGS Gauging Station Precipitation occurs before runoff (.5 inch of rainfall 1 hour before discharge recorded) 18

19 USGS Gauging Stations 951 VERDE RIVER BLW BARTLETT DAM, AZ SYCAMORE CREEK NEAR FORT MCDOWELL, AZ VERDE RIVER NEAR SCOTTSDALE, AZ. 952 SALT RIVER BLW STEWART MOUNTAIN DAM, AZ. Turbidity at WTP lagged peak Sycamore River discharge by only 2 hours at Midnight (more warning time is needed) Turbidity contained 7% fixed and 3% volatile (organic) suspended solids 19

20 Doppler Radar Data Multi-tier Turbidity Warning System Green light = normal conditions Yellow Light = Doppler radar indicates clouds building in lower Verde River watershed; start monitoring streamflows on Sycamore Creek and Verde River Orange light = precipitation is recorded at stations Red Light = Ratio of flows exceeds 1.1 for Verde River at Beeline Highway relative to Verde River below Bartlett Lake (95113 and 9512). Confirm with on-line turbidity meters. Indicates elevated turbidity will arrive at WTPs within a few hours. 2

21 1 minute Break Associated Press investigation: Pharmaceuticals found in drinking water A vast array of pharmaceuticals including antibiotics, anti-convulsants, mood stabilizers and sex hormones have been found in the drinking water supplies of at least 41 million Americans, an Associated Press investigation shows. March 28 21

22 WTP No substance is a poison by itself. It is the dose that makes a substance a poison... Paracelsus ( ) 1541) 22

23 Analytical Scheme Solid Phase extraction (Oasis ASU Analysis at Arizona Department of Health Services Method development support by a Arizona Water Institute grant 23

24 Calibration Curve for Estradiol Estradiol (E2), Linear Regression ("1/x" weighing), y=719.9x (r=1.) Area Counts 8.E+5 6.E+5 4.E+5 2.E+5.E Concentration, ng/ml LC/MS/MS Compounds 24

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27 Arizona Potential EDC/PPCP Sources Colorado River Wastewater discharges into rivers and groundwater Leaking septic systems Houseboats & direct contact (recreation) A Few Numbers Source 2 ng/l & Blank 2 to 1 ng/l 1 to 2 ng/l 2 ng/l to 1 ug/l > 1 ug/l CAP Canal from Colorado River (SRP water a little lower) Steroids Others Caffeine Carbamazepine Meprobamate Naproxen Sucralose Ibuprofen Diclofenac None None Activated sludge WWTP with nitrification Steroids Others Fluoxetine caffeine, cotinine, diuron, ibuprofen, naproxen carbazepine, hydrocodone, meprobamate, sulfamethoxazole, DEET, Erythromycin, trimethoprim, primidone, dilantin, triclosan, diclofenac, sucralose none Raw wastewater A few None Estrogens Fluoxetine Testosterone, Progesterone, hydrocodone, meprobamate, pentoxifylline, DEET, erythromycin, trimethoprim, primidone, carbamazepine, dilantin, diclofenac Ibuprofen, naproxen, triclosan, sucralose, acetominophen, caffeine, cotinine, oxybenzone, sulfamethoxazole 27

28 Occurrence of Chemotherapy Drugs Irinotecan Tamoxifen Daunorubicin Ccl.phosphamide Series 1 Hospital A 4.44 Hospital B Hospital D Hospital E 3.1 WWTP Influent 1.34 WWTP Effluent Series 2 Hospital A.7.9 Hospital B.48 Hospital C.39 WWTP Influent.49 WWTP Effluent Sedona Area Sampling 28

29 The Challenge of ppt Data analysis Sample Name Caffeine Ibuprofen Triclosan Sucralose lab blank 1.41 ND 1.4 field blank 1.12 ND.97 Sedona A 3.95 ND.78 Sedona A Duplicate Sedona B Sedona C Sedona D 6.95 ND 1.56 Verde E Verde E (Duplicate) Verde F 13.1 ND 1.51 Verde G 7.99 ND 2.23 Verde H 4.91 ND 1.7 Verde I 6.19 ND 1.16 Verde I (duplicate) 5.83 ND.68 Hwy 87 at Beeline 25.5 ND 1.4 Blue Point Bridge WTP Raw water 9.49 ND 1.16 WTP Settled water 13.3 ND WTP after chlorine WWTP raw WWTP treated WWTP treated - post UV Effect of PAC (AC8) dose on BPA, E2, and EE2 removal in SRPW (contact time = 4 h) 1 BPA E2 EE2 Percentage remaining (%) PAC dose (mg/l) Yoon et al. 29

30 GAC in Column Tests (RSSCTs) C/Co Dilantin TCEP Carbamazepine DEET Atrazine Diazepam Estriol Ethynylestradiol Estrone Bed Volumes Experiments by F. Cannon Full-Scale Water Treatment Plants From Across the USA From: Removal of EDCs and Pharmaceuticals in Drinking and Reuse Treatment Processes [Project #2758] by Shane A. Snyder, Eric C. Wert, Hongxia Lei, Paul Westerhoff, and Yeomin Yoon 3

31 31

32 Full-scale performance follows lab-scale predictions Example Conventional WTP with Cl 2 Full-scale performance follows lab-scale predictions Example WTP with Ozone 32

33 Summary of Selected Compounds (X: 25-5% XX: 5-9% XXX: >9% Removal) Analyte Coag PAC Cl2 O3 UV Iopromide X X XX XX Meprobamate X XX Sulfamethoxazole X XXX XXX XXX Gemfibrozil DEET X X X X XXX XX TCEP X Galaxolide XX X XX? Atrazine XX XX XX Carbamazepine Ethynylestradiol XX XX XXX XXX XXX XXX Testosterone X XX X XXX XX Androstenedione X XX X XX(X) XX Benzo[a]pyrene Progesterone X X XX XX XX X XX XX(X)? XX Oxybenzone XXX XXX XXX XX Pyrene XXX X XXX? Shifting from Trace Organics to Bulk Organics 33

34 NOM Isolation & Characterization NOM is made of unique chemical groups (acids, neutrals,..) Each group has different removal capabilities and ability to form DBPs This work with Carollo and Malcolm Pirnie helped them interpret trends in water sources and climatic events on NOM behaviour and treatment Sampling Locations & Time Location Sample Date Volume liters ph -- DOC mgc/l TDN mgn/l DON mgn/l Salt River Climatological 12/ Verde River Climatological 12/ Verde River Climatological 1/ Saguaro Lake Lake 3/ Bartlett Lake Lake 3/ Lake Pleasant Saguaro Lake Coagulated Lake Treated Lake 3/28 3/ Carbon recovery during isolation averaged 95% (77%-145%) 34

35 Distribution of DOC in organic matter mg-doc/l Salt River 12/27 Colloids HPO-A HPO-N AMP-A AMP-N HPI Verde River 12/27 Verde River 1/28 Saguaro Lake 3/28 Bartlett Lake 3/28 Lake Pleasant 3/28 Saguaro Lake Coagulated 3/28 7 Colloids HPO-A HPO-N AMP-A AMP-N HPI 6 5 mg-doc/l % Total DOC accounted for by Individual DOM Fractions 1% 8% 6% 4% 2% % Salt River 12/27 Salt River 12/27 Climatological Verde River Verde River Saguaro Lake Typical Bartlett Conditions Lake Lake Pleasant Saguaro Treated Lake 12/27 1/28 3/28 3/28 3/28 Coagulated 3/28 Verde River 12/27 Verde River 1/28 Saguaro Lake 3/28 Bartlett Lake 3/28 Lake Pleasant 3/28 Saguaro Lake Coagulated 3/28 35

36 Effect of Coagulation on NOM distribution ppb C 21% Raw Coagulated Alum dose of ~ 8 mg Alum/mg DOC *Resulting in 33% reduction of DOC DOC (mg/l) ppb C 42% 1 ppb C 2% 22 ppb C 34% - 6 ppb C -39% 35 ppb C 3%. Colloids HPO-A HPO-N AMP-A AMP-N HPI NOM Fraction Simulated Distribution System DBP formation testing Each NOM isolate was dissolved in water Each isolate was chlorinated under typical levels and incubated for 24 or 12 hours THM & HAA levels measured 36

37 . 8 Colloids HPO-A HPO-N AMP-A AMP-N HPI nmol/l Reconstruction of whole water TTHM- FP for 1 hour 2 1 Percent of TTHMs formed by each fraction 1% 8% 6% 4% 2% Salt River 12/27 Climatological Verde River Verde River Saguaro Lake Typical Bartlett Conditions Lake Lake Pleasant Treated 12/27 1/28 3/28 3/28 3/28 Saguaro Lake Coagulated 3/28 Similar trends for 12 hr (Acid fractions dominate) % Salt River 12/27 Verde River 12/27 Verde River 1/28 Saguaro Lake 3/28 Bartlett Lake 3/28 Lake Pleasant 3/28 Saguaro Lake Coagulated 3/28 12 hr HAA5 Formation Potential 4 Colloids HPO-A HPO-N AMP-A AMP-N HPI 35 3 nmol/l Salt River 12/27 Verde River 12/27 Verde River 1/28 Saguaro Lake 3/28 Bartlett Lake 3/28 Lake Pleasant 3/28 Saguaro Lake Coagulated 3/28 37

38 Summary No distinct difference was present between climatological, lake, or treated NOM pools The dominance (% of DOC in initial water) was as follows: HPO-A > Colloids > HPI > AMP-A > HPO-N > AMP-N All NOM isolates form both TTHMs and HAAs but specific NOM isolates are more reactive than others. HPO-A > Colloid > HPI > AMP-A > HPO-N > AMP-N Coagulation was observed to be better at removing colloids and acid fractions while not removing a notable portion of the neutrals. Higher SUVA NOM isolates react more rapidly to form TTHMs than lower SUVA NOM isolates. GAC to Remove Organics & DBP Precursors DBP Precursors include: organic carbon bromide organic nitrogen 38

39 Schematic of RSSCTs set Pump 1.5 cm 1. cm 7. cm 1. cm Inlet Endcap Glass Bead Glass Wool GAC Glass Wool Feed Water samples 1.5 cm.5 cm Glass Bead Glass Wool RSSCT Parameters Parameter EBCT (min) Loading Rate (cm/min) Particle Radius (cm) Length of Media (cm) GAC Simulated Pilot Scale Norit 8x2 mesh RSSCT x 17 mesh (.9 to.16 cm) RSSCT Sampling and SDS testing Project conducted in cooperation with City of Phoenix, Carollo Engineers and Malcolm Pirnie Inc. Samples were collected every 12 hours in the first 3 days and then once per day during RSSCT test Parameters monitored: DOC, TDN and UV254. Simulated distribution system (SDS) test at 2%, 4%, 6% and 8% of UV254 breakthrough. 72 hours and 12 hours holding time for SDS (Analyzed by City of Phoenix) 39

40 Organic Matter Breakthrough Curves.8.7 RSSCT Effluent UVA 254 (cm -1 ) th street 7.5 EBCT Union Hill 7.5 EBCT Val Vista 7.5 EBCT. - 5, 1, 15, 2, 25, 3, 35, BV treated Normalized UVA breakthrough 1..9 Fraction UVA254 in RSSCT Effluent th street 7.5 EBCT Union Hill 7.5 EBCT Val Vista 7.5 EBCT - 5, 1, 15, 2, 25, 3, 35, BV treated 4

41 DOC Breakthrough RSSCT Effluent DOC (mg/l) th street 7.5 EBCT Union Hill 7.5 EBCT Val Vista 7.5 EBCT - 5, 1, 15, 2, 25, 3, BV treated Normalized DOC Breakthrough 1. Fraction remaining of DOC in RSSCT Effluent th street 7.5 EBCT Union Hill 7.5 EBCT Val Vista 7.5 EBCT - 5, 1, 15, 2, 25, 3, BV treated 41

42 Modeling DOC Breakthrough January-28 Normalized TOC Concentration, C/C Bed Volumes R-squared =.8998 Root MSE = UH WTP (predicted) UH WTP (observed) SUVA Breakthrough UVA material is preferentially removed fraction of organic matter 42

43 Organic nitrogen can form N-DBPs DOC is preferentially removed over DON Both are part of the organic matter pool SDS test results THMs or HA th St. 12h THM, Oct 27 24th St. 72h THM, Oct 27 24th St. 12h HAA5, Oct 27 24th St. 72h HAA5, Oct 27 VV WTP 12h THM, Oct 27 VV WTP 72h THM, Oct 27 VV WTP 12h HAA5, Oct 27 VV WTP 72h HAA5, Oct 27 Target FW TOC THM Goal HAA5 Goal 2% BT 24th Street Raw DOC = 4.7 ppm Settled Water (RSSCT Feed) DOC = 2.75 ppm Val Vista Raw DOC = 4.8 ppm Settled Water (RSSCT Feed) DOC = 2.71 ppm 4% BT 6% BT 8% BT Feed Water TOC (mg/l) SDS testing of feed water and RSSCT effluent of October 24th Street WTP and Val Vista WTP water samples 43

44 Different month different outcome THMs or HAA5 (u th St. 12h THM, Jan 28 24th St. 72h THM, Jan 28 24th St. 12h HAA5,Jan 28 24th St. 72h HAA5, Jan 28 VV WTP 12h THM, Jan 28 VV WTP 72h THM, Jan 28 VV WTP 12h HAA5, Jan 28 VV WTP 72h HAA5, Jan 28 Target FW TOC THM Goal HAA5 Goal 2% BT 24th Street Raw DOC = 5.8 ppm Settled Water (RSSCT Feed) DOC = 3.92 ppm Val Vista Raw DOC = 4.3 ppm Settled Water (RSSCT Feed) DOC = 3.17 ppm 4% BT Feed Water 5 8% BT 6% BT 25 4% BT 2% BT TOC (mg/l) 6% BT 8% BT Feed Water SDS testing of feed water and RSSCT effluent of January 24th Street WTP and Val Vista WTP water samples Br/DOC Ratio changes during GAC operation and affects DBP speciation 24 hours incubation 24 hours incubation TTHM (ppb) CHBr3 CHClBr2 CHCl2Br CHCl3 Br/TOC Feed 1% 8% 6% 4% 2% % Feed Br/DOC Granular activated carbon removes DOC initially, but not bromide, so THM formation shifts to a greater mass concentration of brominated THM species 44

45 Removal of DBPs after they form? Not an ideal approach Air stripping is viable for removing chlorinated THMs Photoloysis is possible, but involves large energy input Gerrity et al 28 Future Directions & Discussion Where do you want to see our research go in 29? Continued monitoring of EDC/PPCPs at potential hot spot locations Consideration of climate change on water quality Water-energy nexus issues related to water quality in central Arizona Characterization of organic colloid removal by different treatment trains As T&O levels increase be able to respond with key research needs 45