Pilot Testing El Paso s Advanced Water Purification Facility Caroline Russell, Dan Olson, Sanaan Villalobos, Gilbert Trejo Imagine the result July 17, 2015
Acknowledgements El Paso Water Utilities: John Balliew Fernie Rico Carlos Dominguez Aide Zamarron ARCADIS Brent Alspach Corin Marron Chelsea Francis George Maseeh Texas Commission on Environmental Quality (TCEQ) UTEP Shane Walker Graduate students
Current Drought Conditions in El Paso Elephant Butte Reservoir June 2, 1994 July 8, 2013 Source: NASA 3 6 August 2015
Long History of Conservation and Reuse 1963:EPWU began delivering reclaimed water for irrigation, industrial, and construction uses. 1985: EPWU began using reclaimed water treated to drinking water standards for aquifer recharge (Fred Hervey WRP) gpcd: Reduced from 225 in the 1970s to 132 in 2013
220 Non-Drought Year 200 180 River Water 160 MGD 140 120 100 80 Underground Water 60 40 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct Supply Peak Water Use
220 Drought Year 200 180 River Water 160 MGD 140 120 100 80 Underground Water 60 6 40 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 6 August 2015 2014 ARCADIS Supply Peak Water Use
220 Drought Year Without River Water 200 180 MGD 160 140 120 Underground Water 100 80 May June July Supply Peak Water Use
220 Drought Year Without River Water 200 180 MGD 160 140 Purified Water 120 Underground Water 100 80 May June July Supply Peak Water Use
Project Evolution: Feasibility Assessment and Policy Changes in 2012-13 Initial feasibility assessment completed in 2012 covering IPR, wetlands restoration, and DPR concepts Business case for potable reuse developed May 8, 2013: EPWU Public Service Board approves reprogramming of capital funding from purple pipe projects to potable reuse
Advanced Water Purification Facility Concept Bustamante WWTP with Additional Treatment (29.2 MGD average flow) 10 MGD Advanced Water Purification Facility Distribution System Residuals Handling MF Backwash = 1.0 MGD RO or NF Concentrate = 1.8 MGD Riverside Irrigation Canal 10
Phase I: Complete Water quality review and sampling Initial regulatory coordination Alternatives evaluation and conceptual design Independent advisory panel engagements Pilot testing plan Public outreach (continuous) 11
Source Water: Bustamante WWTP Screening/ Grit Removal Pre-Aeration Primary Settling Activated Sludge Secondary Settling Cl 2 Discharge to Riverside Canal Return Activated Sludge 10 MGD Effluent NH3 and NO3 Concentration (mg/l as N) 12 30 25 20 15 10 5 0 Apr-14 May-14 Jun-14 Jul-14 Aug-14 Sep-14 Oct-14 Effluent NH3 Effluent Nitrate 30 per. Mov. Avg. (Effluent NH3) 30 per. Mov. Avg. (Effluent Nitrate) Denitrifying Filters To AWPF
Simplified Process Schematic Additional Treatment at Bustamante WWTP 1 Advanced Water Purification Facility 2 Secondary Clarifier Effluent MF/UF NF/RO Cl 2 Disinfection Denitrifying Filters Backwash Concentrate UV AOP GAC for H 2 O 2 Quenching Clearwell 1 Additional treatment at Bustamante WWTP includes improvements to achieve full nitrification and prevent ammonia breakthrough. 2 Potential ozone and/or coagulant addition locations and dosages will also be consideredduring pilot testing for potential application during full-scale. 13
Simplified Process Schematic Additional Treatment at Bustamante WWTP 1 Advanced Water Purification Facility 2 Secondary Clarifier Effluent O 3 MF/UF NF/RO Cl 2 Disinfection Denitrifying Filters Backwash Concentrate UV AOP GAC for H 2 O 2 Quenching Clearwell 1 Additional treatment at Bustamante WWTP includes improvements to achieve full nitrification and prevent ammonia breakthrough. 2 Potential ozone and/or coagulant addition locations and dosages will also be consideredduring pilot testing for potential application during full-scale. 14
Testing Plan Approval We find the pilot study protocol acceptable with amendments to include additional data and information in the final pilot study report. TCEQ Approval Letter April 17, 2015 15
Pilot Testing Objectives 1. Meet all TCEQ requirements for pilot testing 2. Demonstrate that the treatment train under consideration meets all water quality goals 3. Establish process design criteria 4. Demonstrate stable and reliable performance 5. Characterize the waste streams to facilitate permitting and design of residuals handling components 6. Determine the best options for online monitoring, alarms, and controls 16
Key Elements to Testing Approach Pilot- Scale Testing Secondary Clarifier Effluent Denitrifying Filters O 3 MF/UF Backwash NF/RO Concentrate UV AOP GAC Bench- Scale Testing Coagulation evaluation Corrosion/pipe loop testing 17
Test Program Nine-month pilot testing program Simulate ultimate full-scale AWPF Four stages of testing: Stage 1: Optimization Stage 2: Demo Testing Stage 3: Ext. Operation Stage 4: Additional Testing Denitrifying filter acclimation Optimization testing for the unit processes Formal 30-day testing window under optimized conditions Continued testing under optimized conditions (following CIP) Potentially assess coagulant addition Challenge testing
Denitrification Filters 19
Membrane Filtration 20
NF/RO Membranes 21
UV-AOP & GAC UV-AOP 22
Pilot-Scale Online Monitoring TOC, Ammonia, & Nitrate Turbidity, Pressure Decay, Flow, & Temperature Chloramines, TOC, Turbidity, Conductivity, Pressure, Flow, Temperature, & ph Secondary Clarifier Effluent O 3 MF/UF NF/RO Cl 2 Disinfection Denitrifying Filters Backwash Concentrate UV AOP GAC for H 2 O 2 Quenching Clearwell TOC, Turbidity, Ammonia, Nitrate, & Nitrite UVT, Reactor Power Level, & UV Intensity Flow & Pressure 23
Denitrification Filter Performance Parameter Influent (Average) Effluent (Average) Nitrate, mg/l as N 8.0 1.5 June 29 July 1, 2015 24
Stage 1 MF Performance Data 25
MF Membrane Filtrate Turbidity 26
Stage 1 UF Performance Data 27
UF Membrane Filtrate Turbidity 28
NF/RO Performance Parameter NF/RO Feed RO Permeate NF1 Permeate NF2 Permeate ph 7.44 6.15 6.03 6.56 Alkalinity,mg/L as CaCO 3 125 8.6 7.0 25.5 Calcium, mg/l 79 ND ND 1.8 Nitrate, mg/l as N 2.9 0.4 0.72 2.15 TDS, mg/l 1,100 20 28 155 Average concentrations measured over first month of operation 29
GAC Peroxide Quenching EBCT Catalytic Bituminous Peroxide concentration in mg/l Catalytic Coconut Shell Reagglomerated Bituminous 0 sec 1.6 1.5 1.4 15 sec 1.1 1.1 1.1 45 sec 0.6 0.2 0.5 1 min 15 sec 0.3 0.0 0.2 2 min 15 sec 0.1 ND 0.1 3 min 15 sec 0.0 ND ND 4 min 15 sec ND ND ND July 7, 2015 30
Summary and Next Steps Pilot testing addresses TCEQ requirements and also demonstrates process train to meet water quality goals Trouble-shooting at pilot scale provides value for smoother full-scale implementation Next steps for pilot testing: Stage 2 and 3 testing Pipe loop testing Integration of ozone Challenge testing 31
El Paso has been a leader in water reuse for decades. Advanced technology makes purified water safe to drink. Purified water is a local, drought-proof, sustainable supply for our community. H2OTOGETHER.ORG 32
Imagine the result 33 6 August 2015 2014 ARCADIS