San Antonio. Water System BRACKISH GROUNDWATER DESALINATION PROJECT. Bill Stein, PG. LBG-Guyton Associates. San Antonio AMTA/AWWA 1

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1 San Antonio Water System BRACKISH GROUNDWATER DESALINATION PROJECT Bill Stein, PG LBG-Guyton Associates San Antonio AMTA/AWWA 1

2 Presentation Outline Brackish Water What? Why? Feasibility Study / Test Wells Program Design Production Wells Treatment Plant Injection Wells Project Summary AMTA/AWWA 2

3 What is Brackish Water? Freshwater Brackish Water Saline Water Seawater Brine TDS* < 1,000 mg/l TDS = 1,000-10,000 mg/l TDS > 10,000 mg/l TDS ~ 35,000 mg/l TDS ~100,000 mg/l USDW * TDS = Total Dissolved Solids AMTA/AWWA 3

4 Why use Brackish Water? Alternative Resource Texas 2002 Desalination Initiative Resource close to San Antonio to make it cost effective Un-tapped resource Large volumes of brackish water AMTA/AWWA 4

5 Feasibility Study March 2006 Test Wells Aug May 2008 AMTA/AWWA 5

6 General Geology Wilcox Formation is deep and gets deeper toward the coast 1,000 ft. 1,226 ft. 1,784 ft. Land Upper Wilcox aquitard isolates the freshwater Carrizo Aquifer from the brackish Wilcox 300 to 400 feet of producible Sand in the lower Wilcox 1,804 ft. Not to Scale AMTA/AWWA 6

7 Water Quality Wilcox Formation Sodium Sulfate/Chloride type chemistry TDS = 1,300 1,500 mg/l Sodium Absorption Ratio > 10 Not Good for Irrigation AMTA/AWWA 7

8 Program Design Phase 1 10 MGD permeate 12 MGD blended 12 or 13 Production Wells 45 miles integration pipeline Reverse Osmosis Treatment Plant 2 or 3 Injection wells AMTA/AWWA 8

9 Production Wells Brackish Source First 8 wells Constructed BGD-1 thru BGD-4 (Oct 2012) BGD-5 thru BGD-8 (Apr 2013) Production Rate = 800 1,000 gpm TDS = 1,300 to 1,500 mg/l BGD-9 thru -13 (designed 2013) Under CMAR (construct 2014) AMTA/AWWA 9

10 SAWS Water Strategy SAWS Averaged 183 MGD in 2012 AMTA/AWWA 10

11 Planned Phasing Permeate Finished Water Phase I 10 MGD 12 MGD Phase II 20 MGD 24 MGD Phase III 25 MGD 30 MGD 30 MGD Capacity at Buildout Modular 2 Parallel Systems (Process Trains) of 15 MGD Each Parallel Systems Carried Through to Post Treatment Interconnections for Reliability 11 AMTA/AWWA 11

12 Reverse Osmosis Skid Units 12 AMTA/AWWA 12

13 SAWS BGD RO Configuration Pretreatment M Stage 1 Membrane Array 20 Vessels, 7 Elements Primary RO Unit #1 Stage 2 Membrane Array Permeate RO Feed Pump #1 20 Vessels, 7 Elements 20 Vessels, 7 Elements M RO Feed Pump #2 Stage 1 Membrane Array 20 Vessels, 7 Elements 20 Vessels, 7 Elements Primary RO Unit #2 Stage 2 Membrane Array 20 Vessels, 7 Elements M Booster Pump Concentrator RO Unit #1 Stage 3 Membrane Array 16 Vessels, 7 Elements AMTA/AWWA 13 Concentrate

14 RO Plant Location Co-location with SAWS Twin Oaks ASR Facility 14 AMTA/AWWA 14

15 Production Well Land Surface TD = 1,600 ft. Austin Chalk Eagle Ford Shale, Buda Limestone, & Del Rio Clay Carrizo Sand (Fresh Water) Upper Wilcox Clay Wilcox Sand (Brackish Water) Midway Shale Navarro Clay Anacacho Limestone Georgetown Edwards & Upper Glen Rose Limestone Not to Scale Production Zone ~ 600 ft. Thick Confining Zone ~2,360 ft. Thick Injection Zone ~ 860 ft. Thick TD = 5,040 ft. Injection Well AMTA/AWWA 15

16 Classes of Injection Wells I. hazardous wastes, industrial non-hazardous liquids, or municipal wastewater beneath the lowermost USDW II. brines and other fluids associated with oil and gas production, and hydrocarbons for storage III. fluids associated with solution mining of minerals beneath the lowermost USDW IV. hazardous or radioactive wastes into or above USDWs. These wells are banned unless authorized under a federal or state ground water remediation project V. inject non-hazardous fluids into or above USDWs and are typically shallow, on-site disposal systems VI. Sequestration of CO2 AMTA/AWWA 16

17 SAWS is first to get TCEQ General Permit for Class 1 injection well to dispose of the RO concentrate ADVANTAGE a minimum of 1/4-mile area of review around each injection well a local and regional hydrogeologic summary well construction engineering injection volumes and rates mechanical integrity testing previous 13-month review period down to about 60 days AMTA/AWWA 17

18 Class 1 Injection Test Well Concentrate Disposal Multiple Casing Strings protects USDW Injection Zone Edwards & upper Glen Rose Limestones 800 feet open hole completion Total Depth: 5,000 5,300 feet Native Edwards water salinity 90,000 mg/l TDS 450 gpm Injection Rate Two Class I Injection Wells for Phase I about 1.1 MGD of about 15,000 mg/l concentrate Well Nos. 2 & 3 (design 2013) Construct under CMAR (2014) AMTA/AWWA 18

19 Team and Timeline Today PM Selection Conceptual Design Phase Design Phase Program Management and Inspection CMAR Selection Pre - Construction Phase Construction Phase Commissioning Phase Work by Separate Contractors Inj. Well # 1 Const. Well Pkg. 1 A (# 1-4 ) Construction TEAM Project Manager - Black & Veatch Wells LBG-Guyton Conveyance URS Treatment Tetra Tech Well Pkg. 1 B (# 5-8 ) Construction Electrical / I&C Gupta & Assoc. AMTA/AWWA 19

20 SAWS Program Summary Production Wells with additional wells later (800 1,000 gpm each) Raw Water Collection System 10 MGD Reverse Osmosis Treatment Plant 2-3 Class I Injection Wells with up to 5 permitted 1.1 MGD of concentrate at about 15,000 mg/l TDS Much less than Edwards Native AMTA/AWWA 20

21 SAWS Program Summary SAWS Brackish Groundwater Desalination (BGD) Program located in southern Bexar County on SAWS ASR property Uses an un-tapped resource Takes advantage of State funding opportunities Three Phase Program Phase 1 10 MGD (2016) Phase 2 10 MGD (2021) Phase MGD (2026) AMTA/AWWA 21

22 Bill Stein LBG-Guyton Associates AMTA/AWWA 22 (210)