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1. Roll Call/Call to Order
The meeting was called to order by Subcommittee Chair, Mark Murphy, at 11:59 a.m. Those present and absent were: Present: Mark Murphy Chairperson-Representative, Mayor Mitch Basefsky Representative, City Manager Chuck Freitas Representative, City Manager Placido dos Santos Representative, City Manager Alan Tonelson Representative, Ward 1 Absent: Brian Wong Representative, City Manager Kelly Lee Representative, Ward 6 Tucson Water Staff Present: Wally Wilson Chief Hydrologist Fernando Molina Water Program Supervisor Daniel Quintanar Project Manager
Kris LaFleur Staff Assistant Johanna Hernandez Staff Assistant Others Present: Chris Avery City of Tucson, Attorney’s Office Kelly Reynolds University of Arizona Jonathon Sexton University of Arizona
2. Announcements – Member Freitas provided a National Geographic article on disinfecting water in third world countries with the sun’s energy.
3. Call to Audience – No action taken. 4. Review & Approval of February 25, 2015 Legal Action Report and Meeting Minutes
– Member Tonelson motioned to approve the Legal Action Report and Meeting Minutes of February 25, 2015. Member Freitas seconded. Motion passed unanimously by a voice vote of 5-0.
5. Research Update – Dr. Kelly Reynolds and Dr. Jonathan Sexton provided a PowerPoint update on the status of various research projects the University of Arizona is working on in conjunction with Tucson Water.
CITIZENS’ WATER ADVISORY COMMITTEE (CWAC)
Technical/Planning and Policy Subcommittee Wednesday, March 25, 2015, 12:00 p.m.
Director’s Conference Room Tucson Water, 3rd Floor
310 W. Alameda Street, Tucson, Arizona
Legal Action Report
Citizens’ Water Advisory Committee, Technical/Planning and Policy Subcommittee Legal Action Report March 25, 2015
Dr. Sexton reported on the validation of Endetec. Endetec is a semi-quantitative method for detecting E.coli and total chloroforms. Endetec results were compared to the Colilert detection method. Endetec results are available in 4-18 hours, are machine read, and are semi-quantitative. These were compared to Colilert results, which are available in 18-24 hours, are human read, and are non-quantitative. Research was able to validate the Endetec. This project is complete. Dr. Reynolds reported on the Risk Assessment Project. Project analyzes data on the presence of fluoride in the water supply. Data reflects that fluoride concentrations vary across sampling points. Data is being analyzed to find trends and future work is aimed at identifying causes of variation for use in developing the model. This project is on-going. Dr. Reynolds reported on a Smartphone application designed for detection of contaminants in the water supply. The application uses paper microfluidics and biosensors in the phone to monitor water quality. The method detection limits are very low, the application is field ready, and the results are available in real time (90 seconds to 10 minutes). As technology advances, the accuracy and effectiveness of the method are increasing. Several areas of advancement of this technology are being considered. This project is on-going.
6. Inter AMA-Firming Update – Tucson Water staff member Wally Wilson led a discussion on the status of the Tucson-Phoenix Inter-AMA Firming agreement. It was noted that Tucson Water, the City of Phoenix and Metro Water are continuing to work with CAP on a framework for the execution of the signed firming agreements between utilities. The framework would need to meet needs of the various parties involved. The parties are considering their options for moving forward and identifying possible solutions.
7. Future Meetings/Agenda Items – Members were requested to consider items they would like to address in future meetings. See projected agenda for further information.
8. Adjournment – Meeting adjourned at 1:16 p.m.
TPP Legal Action Report 2 March 25, 2015
Tucson Water- University of Arizona
Project Updates
March 25, 2015
Kelly A. Reynolds, MSPH, PhD, Associate Professor, Director Jonathan D. Sexton, PhD, Research Specialist, K-12 Outreach
Robert Canales, PhD, Assistant Professor
Environment, Exposure Science and Risk Assessment Center (ESRAC) Mel & Enid Zuckerman College of Public Health
The University of Arizona, Tucson, AZ
1
Endetec Validation
Kelly A. Reynolds, PhD, Associate Professor, Jonathan D. Sexton, PhD, Research Specialist, K-12 Outreach
Endetec
Pros
• Results in 18 hours or less
• Mechanically read
• Notifications of results
• Semi-quantitative
Cons
• Longer learning curve
• Sample number dependent on model (ie. 16 or 24)
Level of Severity
Seeded Water
• Water was seeded with Escherichia coli and Serratia rubidaea
• No discrepancies between methods for concentrations ranging 10-107 cfu/100mL
• Concentrations <10 resulted in mixed results
– Likely due to difficulties in diluting
• Level of severity was in the range of plate count concentrations
Drinking Water
• 150 drinking water samples collected in the Tucson area
• All negative for total coliforms except 1 sample
– Low level of severity
– No discrepancies between methods
Reclaimed Water
• 18 reclaimed water samples were collected
• 66.7% (12/18) positive for total coliforms
– No discrepancies between methods
– Low-Medium level of severity
Software update 2.0.4
• Improved user interface
– Decreased learning curve
• Improved quantitative abilities
Quantitative Validation
• E. coli only
Endetec E. coli Concentration
(cfu/100mL)
Plate Count Concentration
(cfu/100mL)
Endetec Total Coliform
Concentration (cfu/100mL)
Plate Count Concentration
(cfu/100mL)
10^8 2.76E+09 10^9 2.76E+09
10^7 2.85E+08 10^8 2.85E+08
10^6 2.72E+07 10^6 2.72E+07
10^5 2.52E+06 10^6 2.52E+06
10^4 2.26E+05 10^5 2.26E+05
3.07E+03 2.90E+04 10^4 2.90E+04
238 2.70E+03 2.38E+03 2.70E+03
36 305 320 305
Quantitative Validation
• S. rubidea only
Endetec Total Coliform
Concentration (cfu/100mL)
Plate Count Concentration
(cfu/100mL)
10^7 4.55E+09
10^6 4.75E+08
10^4 4.85E+07
1.37E+03 4.20E+06
330 5.15E+05
Quantitative Validation
• E. coli and S. rubidea
Endetec E. coli Concentration
(cfu/100mL)
E. coli Plate Count
Concentration (cfu/100mL)
Endetec Total Coliform
Concentration (cfu/100mL)
Total Coliform Plate
Count Concentration (cfu/100mL)
10^8 2.55E+09 10^9 5.95E+09
10^7 2.85E+08 10^8 6.70E+08
10^6 1.90E+07 10^6 5.80E+07
10^5 2.35E+06 10^6 6.30E+06
10^4 2.50E+05 10^5 6.00E+05
6.55E+03 2.80E+04 10^4 7.60E+04
515 2.35E+03 9.13E+03 8.45E+03
53 400 317 1.00E+03
5 27 77 75
1 2 7 6
Future Work
• Comparison of methods with water of varying quality
– Microbial and chemical
• Quantitative validation with different bacteria
– Coliforms and non-coliforms
Tucson Water Risk Assessment Project
Robert Canales, PhD, Assistant Professor Kelly A. Reynolds, PhD, Associate Professor
Sally Littau, BS, MT(ASCP) Health Research Coordinator
Environment, Exposure Science and Risk Assessment Center (ESRAC) Mel & Enid Zuckerman College of Public Health
The University of Arizona, Tucson, AZ
14
Brief Fluoride Summary
• Fluoride analysis has replaced the Chromium-6/Total Chromium analysis due to insufficient data currently collected
• 2 recent news reports suggested Tucson water is low in fluoride concentrations
– Arizona Daily Star Nov 2, 2014
– Arizona Daily Wildcat, Nov 11, 2014
15
Fluoride Benefits and Risks
• At low intake levels, fluoride has can have therapeutic value in the prevention of dental caries
• Slightly higher levels can lead to dental fluorosis - a condition in which the enamel covering of the teeth fails to crystallize properly – More of a concern for children during the period of enamel
development – Possible problems range from barely discernible markings to
brown stains and surface pitting – Some studies show that climate may be a factor as well
• Prolonged high intake can result in skeletal fluorosis - a condition which may increase bone brittleness and risk of bone fracture
• In high-dose cases, severe bone abnormalities can develop
EPA 820-R-10-019, December 2010 16
Current Fluoride Guidelines
–Regulated by EPA
• Maximum contaminant level goal (MCLG) is 4.0 mg/L (4.0 ppm)
• Enforceable MCL is 4.0 mg/L
• Non enforceable secondary level of 2 mg/L
17
American Dental Association
• ADA recommendation
– Optimum water fluoride concentration of 0.7 to 1.2 ppm
– Was established to maximize the decay preventive benefit
– 2014 article by American Academy of Pediatric Dentistry “Guideline on Fluoride Therapy”
• Department of Health and Human Services
• Recently proposed 0.7 as the upper limit due to additional sources of fluoride available (toothpaste, for example)
18
Agency for Toxic Substances and Diseases
• ASTDR minimal risk level for sodium fluoride
– Oral Route: 0.6 mg/kg/day
– Endpoint: Musculoskeletal (fluorosis, skeletal fracture)
• Other potential risks:
– High levels: Cancer
– Low levels: Dental caries
19
Questions
• Currently the level of fluoride in Tucson water fluctuates across sampling points and over time
• Does Tucson have plans to fluoridate water?
• Is there anticipation of public concern?
• What are major concerns and considerations?
20
Data Files
• Received 71 data files from TW – 60 are WQZ files; 11 from sites such as Sunset
Ranch, Diamond Bell, Thunderhead etc.
– May enable us to provide displays or data summaries for data combined over all years
• Contains all laboratory data for – Years 2009 to 2014
– All Tucson water systems
– Each WQZ file has data for 10 – 36 sampling points
21
File Formatting
• Original XML files were archived and copied, and copied files were converted to text (.txt) files for easy upload into statistical software (R)
• Joined all years (2009 – 2014) for a given WQZ • Used SAMPLE_DATE field to create 2 fields
corresponding to year and month, for further temporal analysis
• Created new data frames extracting values relevant to analysis of Fluoride
• All commands for formatting and analysis are saved in scripts for quality assurance
22
Potential and Preliminary Analysis
• Use of boxplots (box and whisker plots) to visualize data summaries
23
median
minimum
maximum
25th percentile
75th percentile Any outliers
are indicated as
points beyond
the “whiskers”
Potential and Preliminary Analysis
• Use of boxplots
– Visualize data from each sampling point across a water zone for a particular year
– Visualize data from each sampling point across a water zone for the years 2009 – 2014 combined
– Visualize data from a sampling point for all years by sampling date (month and/or season)
24
25
26
27
Future Work
• Continue exploration along the lines of sample plots, data summaries, and trends
• Explore correlations between Fluoride and metals or other water components/characteristics
• If given coordinates, can map data along sampling points across water zones
28
Future Work
• Indirectly estimate fluoride dose intake via drinking tap water – Use intake data from EPA handbooks or consumption
surveys
• Use additional data sources and assumptions to
estimate cumulative exposure assessment and dose from multiple sources
• Estimate health risks from tap water and cumulative sources – Use of EPA’s dose-response information
29
Statistical Significance
• “What is the minimum amount of values, in general, that are needed to make the risk assessment model statistically significant for any given parameter?”
• What is the specific statistical test of interest? – Do we want to test if concentration values are
statistically different from the MCLG of 4.0 mg/L? – What is the expected standard deviation or variance? – What is the expected effect size or difference in
means?
30
Statistical Significance
• Assumptions – Desired level of significance of 0.05 – Aim to achieve 80% power – One-sample test (test data against a single value such as
the MCL)
• Sample size estimate is
– n ≈ 15 for a large effect size (0.8) – n ≈ 25 for a medium effect size (0.5) – n ≈ 200 for a small effect size (0.2) – Interpretation: to be able to detect a statistically
significant difference that is small requires a greater sample size
31
Statistical Significance
• An effect size is the difference in means divided by the standard deviation
• Assuming a standard deviation of 0.1 mg/L (from preliminary analysis of data), the difference in means is – for a large effect size (0.8), 0.08 – for a medium effect size (0.5), 0.05 – for a small effect size (0.2), 0.02
• If testing the difference from the MCLG of 4.0 mg/L, based on preliminary analysis the expected effect size is likely large, requiring a relatively small sample size (~15) to achieve 80% power
32
SMARTPHONE FOR WATER
QUALITY: Smartphone Detection from Paper
Microfluidics for Monitoring Water Safety
Jeong-Yeol Yoon, PhD, Associate Professor Kelly A. Reynolds, MSPH, PhD, Associate Professor
Department of Agricultural & Biosystems Engineering (Yoon)
Mel & Enid Zuckerman College of Public Health (Reynolds)
The University of Arizona, Tucson, AZ
Yoon & Reynolds
The Idea
34
Yoon & Reynolds
Detection @
optmum angle
utilizing internal
gyro sensor
Scatter from paper
is minimized utilizing
Mie scatter theory
Filtration by
paper fibers
Innovation
• Both paper microfluidics and smartphone-based biosensor have not been utilized for water quality monitoring (especially for pathogens).
• Method has demonstrated extremely low detection limit (10 pg virus antigens or 10 CFU bacteria per mL sample).
35
Yoon & Reynolds
How it works
36
FOR PATHOGENS: FOR CHEMICALS:
Colorimetric assay
using RGB pixel intensities
with double normalization
(to cancel out chip-to-chip variation
and ambient lighting) Detection by Mie scatter
@ optimized angle
Yoon & Reynolds
Filtration by paper fiber
37
Soil particles
@ inlet
Algae
@ inlet
No contaminants
@ channel
Yoon & Reynolds
Smartphone + paper microfluidics
38 Park, Li, McCracken & Yoon, Lab Chip 13: 4832-4840 (2013)
Yoon & Reynolds
Optimization of detection angle
39
Yoon & Reynolds
Mie scatter simulation
40
Yoon & Reynolds
Standard curves
41
Yoon & Reynolds
With Paper Microfluidics + Smartphone Detection
Field water samples
42
Yoon & Reynolds
With Paper Microfluidics + Smartphone Detection
Results w/ 1.5 ppm chlorine
43
With Paper Microfluidics + Smartphone Detection
Able to detect E. coli in the presence of chlorine
Yoon & Reynolds
Chromium (VI) and Chlorine Detection
44
G R
Yoon & Reynolds
B
Sample Loaded
& Flows to Dye 5000 ppb 2000 ppb 1000 ppb
Dye Loaded
In Channel
Before
Sample
Chlorine quantified through green absorbance following N,N-
diethyl-p-phenylenediamine (DPD) dying.
Chromium (VI) concentrations were quantified through green
absorbance following a dying process mid-channel with diphenyl-
carbazide (DPC)/H2SO4.
Preliminary result for cr(vi)
45
-0.05
0
0.05
0.1
0.15
0.2
0.25
0 1 ug/L 100 ug/L
Ab
sorb
ance
Cr(VI) concentration
w/ iPhoneB
G
R
-0.05
0
0.05
0.1
0.15
0.2
0.25
0 1 ug/L 100 ug/L
Ab
sorb
ance
Cr(VI) concentration
w/ AndroidB
G
R
-0.05
0
0.05
0.1
0.15
0.2
0.25
0 1 ug/L 100 ug/L
Ab
sorb
ance
Cr(VI) concentration
w/ iPhone, longer incubationB
G
R
Detection limit of EPA Method 7196A
w/ spectrophotometer = 10-20 ug/L
This method = ca. 1 ug/L
Yoon & Reynolds
Conclusions
• Paper microfluidics with smartphone detection permits rapid and sensitive water quality detection at environmentally significant levels for customizable targets – Single-cell E. coli detection (assay < 90s) – 10 ppb Chromium (VI) detection (< 10 min) – 0.5 ppm Total Chlorine detection (< 10 min)
• Smartphone-based assay allows mobility for potential in-field, real-time detection
• Technology advancing – Improved LED flash technology and smartphone camera
resolution – Improved app, autosearches optimal light scattering angle
46
Multi-channel paper microfluidics
Detection of water quality parameters with paper microfluidics:
pH
Total Chlorine
Hardness Ca2+ and Mg2+
E. coli
Chromium (VI)
Caffeine
47
Yoon & Reynolds
Future work
Repeat assays of E. coli in complex water samples (reuse water)
Comparison with routine Colilert® monitoring
Combined microbe detection
Colorimetric assays for other parameters, including arsenic and dioxin
Advance virus detection method
48
Yoon & Reynolds
Paper Microfluidics:
Particle-based Immunoassay for norovirus
vs.
Immunoagglutination on paper chip
Light Scattering Characteristics
Paper
Photo-resist layer
Open region of paper
Antibody conjugated micro beads
Using antibodies on paper to detect norovirus capsid protein VP1 Experiments to be conducted with recombinant norovirus antigen, and deactivated norovirus capsid (both from identified sources)
Acknowledgements
• Tucson Water – Dan Quintanar
• NSF-WET Center – Dr. Ian Pepper
• Environment, Exposure Science and Risk Assessment Center (ESRAC)
– Dr. Robert Canales – Dr. Jonathan Sexton – Melissa Valdez, MSPH – Sally Littau, BS, MT, (ASCP)
• Biosensors Lab, University of Arizona – Dr. Jeong-Yeol Yoon – Dr. Tu San Park – Dr. Scott Angus – Katherine McCracken
50
Citizens’ Water Advisory Committee Technical Planning, Policy Subcommittee
Projected Agenda
April 22, 2015
• WSA Policy Review/Water Checkbook Update
May 27, 2015
• CAP Joint Recovery Plan – Laura Grignano • Security of Open Water Sources – Allan Tarket
June 24, 2015
• Pending September 23, 2015
• FICO Infrastructure and Plans – Matt Bailey October 28, 2015
• The Impact of Emerging Contaminants on Water Sustainability – Shane Snyder
November 18, 2015
• Pending December 16, 2015
• Pending
Future Agenda Items without a Date: -Reclaimed Plant (Wally) -Cogeneration (Bruce) -Green Valley-Project Renews
Green Valley; Arturo Gabaldon [email protected]
3/23/2015 Page 1 of 1