1. SOUTHMOST REGIONALWATER AUTHORITY
Texas Alliance of
Groundwater Districts
October 29, 2014

2. OUTLINE
• About BPUB
• BPUB Surface Water Supply
and Treatment
• SRWA Brackish Groundwater
Desalination
• SRWA Microfiltration Project
• Benefits and Challenges
• Seawater Desalination
• Long-Term Water Supply
Strategy
• Water-Energy Nexus
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3. ABOUT BPUB
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• Municipally-owned utility
• Commission appointed 7 Member Board with the Mayor serving as
an Ex-Officio voting Member
• Full-service utility:
• Electric, Water, Wastewater & Natural Gas
• 540 Employees
• Approximately 50,000 customers
• $190 million total revenue

4. 4
PRIMARYWATER SOURCE
• Rio Grande
The Rio Grande is a river that
flows from southwestern
Colorado in the United States to
the Gulf of Mexico. Along the
way it forms part of the Mexico–
United States border.
• Falcon/Amistad Lakes

5. 5
Water Supply Management
• TCEQ Watermaster Program
• Municipal Water Rights
• 31,133.631 acre-feet
• 7 day advance order for travel time
• Permit 1838 (Surplus water)
• 40,000 acre-feet
• Intermittently available, depending on river flows
• Maintain resaca levels

6. 6
Brownsville Resacas
Resaca Del Rancho Viejo
Resaca De La Guerra
Town Resaca
Rio Grande

7. Rio Grande at Brownsville Low Flows
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Spring 2001 Summer 2002

8. Rio Grande at Brownsville High Flows
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October 10, 2008 July 26, 2010

9. 9
Off-Channel Reservoirs

10. 10
Water Reservoirs
• Short-term storage
• Total storage capacity
• 187 MG (8 days)
• Reservoir 1 - 48 MG
• Reservoir 2 - 139 MG

11. 11
Surface Water Treatment
• 2 Conventional treatment plants (20 MGD each)
• Provide 76% of potable water to Brownsville

12. 12
Southmost Regional Water Authority Partners
Town of Indian Lake
0.20%
Brownsville Navigation District
2.10%
City of Los Fresnos
2.28%
Valley Municipal Utility District No.2
2.51%
Brownsville Public Utilities Board
92.91%

13. 13
SRWA Background
• SRWA: Conservation and Reclamation
District formed in 1981 to address long-term
regional water supply issues for
southern Cameron County
• Dormant until 2000, then resurrected in
response to the extended drought of
the late 1990’s
• Partners came together to consider
using brackish groundwater as an
alternate water supply

14. 1996
BPUB &
TWDB: Study
on brackish
groundwater
2001
Regional
brackish water
feasibility study
& well field
evaluation
2002
Engineering
design
2004
Brackish
Groundwater
Treatment
Facility
construction
completed
2015
Microfiltration
pretreatment and
expansion
project complete
14
Time Line

15. SRWA Brackish Groundwater Treatment Facility
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16. Brackish Groundwater Desalination
RO Membrane Treatment Facility
• Construction completed in 2004
• 7.5 MGD Design Capacity
• 20 Brackish groundwater wells
• Groundwater: 3,000 mg/L total
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dissolved solids (TDS)
• Concentrate waste stream
13,000 mg/L TDS drain ditch
• TCEQ Discharge Permit: TDS
Daily Max—35,339 mg/L

17. 17
Reverse Osmosis Membrane Process

18. RO Membrane Process--Video
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19. 19
SRWA Brackish Groundwater Wells
• 20 Brackish groundwater wells
• Well depth: approximately 250-300 feet
• Well pump rate: 330 – 400 gpm
• Groundwater: 3,000 mg/L total dissolved
solids (TDS)

20. • Original Construction Costs:
$29 Million
• Funding Source: Revenue Bonds
• 8,400 acre-feet of water rights
savings (equivalent to $17 Million)
• FY 2014 O&M Budget: $3 Million
• Electrical: 23% of operational costs
• Chemicals: 40% of operational costs
• FY2013 Unit Costs:
• $1.42 per kgals (O&M)
• $2.46 per kgals (Debt Service and
O&M)
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SRWA Cost Summary

21. 21
SRWA Microfiltration Project
Pretreatment for RO process
• USEPA reduced arsenic level in drinking
water standards in 2006
• Install 12 MGD Pall microfiltration
system for arsenic and iron removal
• Expands plant capacity to 11 MGD
• Cost - $13 million
• $9,295,000 No-interest TWDB Loan
• $3,795,000 Low-interest (below
market) TWDB Loan
• Estimated construction costs:
$11,413,578.15
• Construction Start Date – May 2013
• Completion Date – January 2015

22. Treatment Process
Degasifier
BRACKISH WATER TREATMENT
Cartridge
Filters
RO
Membrane
Array
Blending
By-Pass
Treated Water
Storage
To Distribution System
Post-treatment
Chemicals
Concentrate
Disposal
Chemical
Pre-treatment
CONCENTRATE
MANAGEMENT AND
DISPOSAL
DELIVERY OF
POTABLE WATER
Energy
Recovery
Turbine
GROUNDWATER
DEVELOPMENT
Collection and
Conveyance System
Well Field
Micro Filtration
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23. 23
SRWA Benefits and Challenges
Benefits
• Alternate water supply
• Independent of Rio Grande
• Water rights savings
• Produces high quality water
• Modular design
Challenges
• Arsenic levels in groundwater
• Higher operating costs
• Discharge permit
• Specialized training (SCMA)

24. • 81st Texas Legislature (2009) provided funding to implement the TWDB Brackish
Resources Aquifer Characterization System (BRACS) program
• 83rd Texas Legislature (2013) provided additional funding for personnel
2.7 billion acre-feet of brackish
groundwater estimated in Texas
Brackish groundwater in the
major and minor aquifers Source: modified from LBG-Guyton, 2003
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25. Brackish Groundwater in
the Gulf Coast Aquifer,
Lower Rio Grande
Valley, Texas
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TWDB Report 383
September 2014

26. Brackish Groundwater Volume
Slightly Saline 40 million acre-feet
Moderately Saline 112 million acre-feet
Very Saline 123 million acre-feet
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27. 27
Brownsville Public Water Supply

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Brownsville Public Water Supply
Projected Proportions after SRWA
54%
46%
Expansion
Surface Water Plants
SRWA

29. 29
Seawater Desalination
Pilot Study: $3,177,408 (Actual)
• TWDB Funding $1,340,000
25 MGD Full-scale facility: $182.4 Million
• (Pilot Study Report, 2008)
2.5 MGD Demonstration: $22.5 Million
• (Project Update, 2011)

30. 30
Long-Term Water Supply Strategy
Diversification
• Surface Water
• Purchase water rights
• Increase storage capacity in resacas
• Brackish Groundwater Desalination
• Southmost Regional Water Authority RO
Treatment Facility
• Seawater Desalination
• Pilot plant – Port of Brownsville
• Texas desal project – proactively
identify environmental concerns
• Phase 1: 2.5 MGD SWRO Plant
• Water Reuse – 8 MGD for Tenaska
Project

31. THANK YOU
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