Regional ASU Regional Water Quality Center Water Quality Algae and Associated Drinking Water Challenges A Cooperative Research and Implementation Program
Arizona State University (Tempe, AZ) Peter Fox, Morteza Abbaszadegan, Marisa Masles and Andrew Buell
Salt River Project Central Arizona Project
City of Phoenix, City of Chandler, City of Tempe, City of Peoria, City of Glendale
Workshop – SRP Pera Club September 21, 2018 Water & Environmental Technology Center Regional Agenda Water Quality Purpose: Provide a forum to review and discuss on-going regional water quality issues, in particular algae-associated issues.
8:15 Refreshments 8:30 Introductions 8:45 Overview of water quality in 2017-2018 in the water supply system (Fox) 9:05 Perspective of Microbial Quality of Central Arizona Source Waters (Abbaszadegan) 9:15 Algal blooms: A Threat to the Environment - Control Strategies using a Non- oxidizing Agent (Abbaszadegan and Alum)
9:25 Stretch
9:35 Craigin (Blue Ridge) Reservoir Stratification Impacts on Water Quality (Ted Flatebo) 9:50 Assessment of the Potential for Quagga Mussel Infestation of Canyon Lake (Lau/Fox) 10:05 Potential removal of Hexavalent Chromium at impacted SRP groundwater wells via the addition of Stannous Chloride (Duong Nguyen) 10:20 Monitoring Algal Abundance and Water Quality in Arizona Reservoirs Through Field Sampling and Remote Sensing (Jazmine Russel) 10:30 Future directions & discussion 11:00 Meeting adjournment
Water & Environmental Technology Center Regional Water Quality Introductions
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Water & Environmental Technology Center Regional Workshop will present results as water Water Quality moves down through the watershed
Water & Environmental Technology Center
Regional Hydrology Affects Water Quality Water Quality (conductance can affect algal dominance)
2500
Lake Pleasant Bartlett Lake Saguaro Lake
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s/cm) μ 1500
1000 Conductivity ( Conductivity
500
0
Water & Environmental Technology Center Regional Water Reservoir stratification over the years Quality
DO (mg/L) 0 3 6 9 12 15 18 0 Bartlett Lake 10 winter & summer 20 Summer Temp (C) 10 13 16 19 22 25 28 31 34 37 40 30 Winter 0 40 10 50 Winter
Depth from surface (m) surface from Depth 20 Summer 60 2/4/2008 8/4/2008 2/1/2010 2/4/2008 8/4/2008 8/2/2010 2/7/2012 8/6/2012 30 70 1/7/2014 8/5/2014 12/2/2014 40 2/1/2010 8/2/2010 2/1/2016 4/4/2016 6/6/2016
50 2/7/2012 8/6/2012 Depth from surface (m) surface from Depth 60 1/7/2014 8/5/2014
70 12/2/2014 2/1/2016
4/4/2016 6/6/2016 Regional Water Reservoir Conditions Affect Water Quality Quality
Lake Pleasant Regional Water Quality Saguaro Lake
DO (mg/L) 0 3 6 9 12 15 18 Temperature (°C) 0 10 15 20 25 30 35 40 0 8/5/2013 Winter 9/10/2013 Winter Summer 10 11/5/2013 8/5/2013 Summer 1/7/2014 10 9/10/2013 3/4/2014 11/5/2013 6/3/2014 8/5/2014 1/7/2014 3/4/2014 20 1/6/2015 20 3/10/2015 6/3/2014 6/2/2015 8/5/2014 8/31/2015 1/6/2015
Depth from surface (m) surface from Depth 1/12/2016 30 3/10/2015
30 (m) surface from Depth 2/1/2016 6/2/2015 3/7/2016 8/31/2015 4/4/2016 1/12/2016 3/7/2016
Destratification typically occurs around October Regional Water Quality Lake Destratification
Outlet from Outlet from bottom bottom
Thermally Stratified Post-stratification - Algae & MIB are on top - Algae & MIB mix with depth - Dead cells sink and - Increased MIB in outlet release MIB - Food and O2 fuels rapid biodegradation Regional Secchi Disk Depth Influenced by Inorganic Water Quality Suspended Sediment and/or Organic Biomass
10 Bartlett Saguaro Lake Pleasant 8
6
4
2 Secchi Disk Depth (m)
0
Typical values in Bartlett: Peak Values in Summer Typical values in Saguaro: Currently Increasing Regional Secchi Disk Depth – Spikes in Spring over Last 4 Water Quality Years
8 Bartlett
Saguaro 6
4
2 Secchi Disk Depth (m)
0
Typical values in Bartlett: Peak Values in Summer Typical values in Saguaro: Currently Increasing Regional Water Common Algal T&O Compounds Quality
Parameter MIB Geosmin (2-methyisoborneol) Taste threshold ~ (1-R-exo)-1,2,7,7- tran-1, 10-dimethyl-trans- Full Name tetramethyl bucyclo- 9-decalol 10 ng/L [2,2,1]-heptan-2-o1
Molecular Formula C11H20O C12H22O Chlorine residual Molecular Weight 168 g-mole-1 182 g-mole-1 Boiling Point 197 oC 165 oC can “mask” odors Aqueous Solubility 195 mg/L 150 mg/L Kow 3.13 3.7 -5 3 -1 -5 3 -1 T&O is a Henry’s Law Constant 5.7610 atm m -mole 6.6610 atm m -mole worldwide issue Structure affecting the publics “confidence” in drinking waters, but is not Source: (Pirbazari et al. 1992) regulated Regional Water Quality Geosmin Data 20 Lake Pleasant Eplimnion 16 Lake Pleasant Hypolimnion
12
8
Geosmin (ng/L) Geosmin 4
0
25 30
Bartlett Lake Eplimnion 20 25 Bartlett Lake Hypolimnion Saguaro Lake Eplimnion 20 15 Saguaro Lake Hypolimnion 15 10
10
Geosmin (ng/L) Geosmin Geosmin (ng/L) Geosmin 5 5
0 0 Regional Water Quality MIB Data – Lake Pleasant
50 Lake Pleasant Eplimnion (R2A)
40
30
20 MIB (ng/L) MIB
10
0
70 Lake Pleasant Hypolimnion (R2B) 60
50
40
30 MIB (ng/L) MIB 20
10
0 Regional 60 Water MIB Data – Bartlett Lake R6A(Bartlett) Quality R2A(Pleasant) 50 R9A(Saguaro)
100 40 Bartlett Lake Eplimnion (R6A) Saguaro MIB = 0.15e0.21x R2 = 0.64 80 0.35x 30 Bartlett MIB = 0.0013e R2 = 0.80 60
20 Epilimnion(ng/L)MIB
40 MIB (ng/L) MIB 10
20 0 5 10 15 20 25 30 0 Epilimnion Temperature (C) 60 Bartlett Lake Hypolimnion (R6B)
40
MIB (ng/L) MIB 20
0 Regional Water MIB Data – Saguaro Lake Quality
120 Saguaro Lake Eplimnion (R9A)
100
80
60 MIB (ng/L)MIB 40
20
0
100 Saguaro Lake Hypolimnion (R9B)
80
60
MIB (ng/L) MIB 40
20
0 Regional Water Quality Most Recent Data - 8/31/2016
Table 2 - Canal Sampling – August 20, 2018 System Sample Description MIB Geosmin (ng/L) (ng/L) Waddell Canal 2.13 <2.0 Highest MIB levels ever CAP Union Hills Inlet <2.0 <2.0 CAP Canal at Cross-connect 2.87 <2.0 recorded in AZ Canal Salt River @ Blue Pt Bridge 4.62 2.66 Verde River @ Beeline 21.13 5.12 AZ Canal above CAP Cross-connect 2.73 <2.0 AZ Canal below CAP Cross-connect 3.32 <2.0 AZ Canal at Highway 87 3.40 <2.0 AZ Canal AZ Canal at Pima Rd. 2.98 <2.0 AZ Canal at 56th St. 3.60 <2.0 AZ Canal - Central Avenue 3.29 <2.0 AZ Canal - Inlet to Glendale WTP 2.86 <2.0 Head of the Consolidated Canal 5.68 2.73 Middle of the Consolidated Canal 6.86 2.65 South Canal below CAP Cross-connect 6.53 3.79 South Tempe Canals Head of the Tempe Canal 7.03 4.67 Tempe Canal - Inlet to Tempe's South Plant 2.72 <2.0 Salt-Gila (July) 2.30 <2.0 Mesa Turnout (July) 2.27 <2.0
Table 3 - Reservoir Samples – August 20-21, 2018 Sample Description Location MIB Geosmin (ng/L) (ng/L) Lake Pleasant (July) Eplimnion <2.0 <2.0 Lake Pleasant (July) Hypolimnion 3.1 <2.0 Verde River @ Beeline 21.1 5.1 Bartlett Reservoir Epilimnion ns ns Bartlett Reservoir Epi-near dock 8.6 <2.0 Bartlett Reservoir Hypolimnion ns ns Salt River @ BluePt Bridge 4.6 2.7 Saguaro Lake Epilimnion ns ns Saguaro Lake Epi - Duplicate ns ns Saguaro Lake Epi-near dock 15.4 <2.0 Saguaro Lake Hypolimnion ns ns Lake Havasu ns ns Verde River at Tangle Creek ns ns Roosevelt at Salt River Inlet ns ns Regional Water Quality What about last year? 8/2/16 Regional Water Quality Total Nitrogen – Higher than last several years but within historic norms Regional Water th Quality Canyon Lake – August 9 2017 Regional Water MIB Growth in AZ canal Quality from below X-Con to Central Ave.
What changed after 2006? -After long-term drought - lower conductivity water -Less frequent changes in water blending -SRP cleaned out forebay below Pima in 2006 Regional Water The Consolidated Canal Quality
• The consolidated canal flows off the SRP South Canal, and provides the water supply for the Chandler WTP • Consistent geosmin production in the canal occurred in 2013 and again in December 2014 • Numerous wells flow into the Consolidated Canal • Groundwater pumping in late 2014 resulted in a tremendous spike due to increased nitrogen levels. • Special sampling was done in December 2014
Water & Environmental Technology Center Regional Water Quality Special Sampling December 2014
• A sampler biked along Consolidated Canal to identify a “hotspot”
Chandler Water Treatment Plant
Sampled on: December 12-13, 2014 Geosmin (ng/L) CH WTP #1 228.7 CH WTP #2 265.1 CH WTP #3 226.7 CH WTP #4 125.4 CH WTP #5 58.3 CH WTP #6 14.6 CH WTP #7 11.7 CH WTP #8 11.4 CH WTP #9 6.9 CH WTP #10 2.4 CH WTP #11 2.4 CH WTP #12 2.1 CH WTP #8a 13.3 CH WTP #8b 12.7 CH WTP #8c 12.8 CH WTP #8d 12.8 Regional Water Quality Special Sampling December 2014
• The hotspot was traced to a spot located 1.5 miles above the Treatment Plant • Water from a well that was extremely high in Nitrogen and overgrown with algae was flowing into the canal and leading to elevated Geosmin levels. • Treatment with Copper Sulfate was recommended and Geosmin levels decreased. Regional Water Copper Application Quality Regional Water MIB Levels Higher in AZ Canal System Quality Compared Against South Canal System
80 75 70 Tempe North Plant In 65 60 Tempe South Plant In 55 50 45 40 35 30 25
WTP Influent Influent MIB (ng/L) WTP 20 15 10 5 0 Regional Water Quality T&O Trends
• Saguaro Lake has consistently produced highest levels of T&O • Minimal production of MIB in canals over last 5 years • Significant production of Geosmin in Consolidated canal for prolonged period in 2013 through this year
Water & Environmental Technology Center Regional Water Quality Long-Term Trend in DOC
12 Lake Pleasant Bartlett Lake Saguaro Lake 10
8
6
DOC DOC (mg/L) 4
2
0 Regional Water Perturbations to the Salt-Verde River Quality System
• Drought – 2001-2005, 2012-Present • Increases Salinity of Salt River
• Fires – Rodeo-Chidisky – 2002 • 468,000 Acres Burnt • Alters Runoff and Carbon Content
• Roosevelt Dam • Raised 77 Feet in 1995 – 20% Increase in storage Regional Water Quality Recent Trends in DOC not apparent
12 Lake Pleasant Bartlett Lake Saguaro Lake 10
8
6
4 DOC DOC (mg/L) 2
0 Regional Water Quality Specific UV Absorbance at 254 nm
8 Lake Pleasant 7 Bartlett Lake 6 Saguaro Lake 5 4 3
2 SUVA L/m/mg) SUVA 1 0 Regional Water Quality DOC Summary
• DOC levels in Salt River reservoirs are showing an increase this year after a decrease over the past 5 years.
• DOC profiles exist in the water column (higher levels near the surface where algae is active)
Water & Environmental Technology Center Regional Water Quality The End!
Water & Environmental Technology Center