Potable Reuse in Texas:
A Glimpse into the New
Water Frontier
Ellen McDonald, Ph.D., P.E.
Alan Plummer Associates, Inc.
Acknowledgments
• City of Brownwood
– David Harris, Director of Utilities
• City of Wichita Falls
– Daniel Nix, Operations Manager
• El Paso Water Utilities
– Irazema Rojas, Environmental
Compliance Manager
• ARCADIS
• Freese and Nichols
Evolution of Reuse in Texas
Direct Potable
Indirect Potable
Unplanned
Planned
Municipal
Industrial
Agricultural
1880
1900
1920
1940
1960
Year
1980
2000
2020
DPR in the Barton Springs Zone?
Major Texas Potable Reuse Projects
• Trinity River Basin
projects
• El Paso
• Colorado River
Municipal Water
District
Evolution of Potable Reuse
WWTP
WTP
Environmental Buffer
?
CRMWD at Big Spring Project
Other DPR Projects In Process
Stay tuned… there are
more on the way!
Wichita Falls Emergency DPR
Project
• Use existing MF/RO facility to treat
effluent from WWTP
• RO permeate to be blended 50/50 with
raw water from lakes
• Blended water to be treated at
conventional WTP
• Pipeline from WWTP to WTP laid
above ground
Source: www.timesrecordnews.com/photos/galleries/2014/feb/04/inside-look-water-reuse-project/12132/#section_headery's
City of Brownwood
Conservation pool: 1424.6 ft
City of Brownwood – Proposed
System (1.5 MGD)
• Estimated Cost - $8.5 Million
• Project Status:
– TWDB funding approved Sept. 2012
– TCEQ construction approval Dec. 2012
• No blending required
• Requires full-scale verification
– Awaiting council approval to move forward
El Paso Water Utilities
Elephant
Butte Reservoir
• Existing
Supplies
18.4% Full as of April 22, 2014
– Rio Grande
– Groundwater
• Hueco Bolson Aquifer
• Mesilla Bolson Aquifer
– Reclaimed water
• Nonpotable reuse
• Groundwater recharge
Advanced Purified WTP Concept
MF Backwash to RBWWTP
Headworks = 1 MGD
Reclaimed
Water
Reclaimed
Water
Customers
Roberto R.
Bustamante
WWTP
with Additional
Treatment
Rio Bosque
Wetland Park
10 MGD
Advanced
Purified
WTP
Brine disposal:
Blend w/WWTP effluent = 1.8 MGD
Outfall
Riverside Irrigation Canal
7.2 MGD
Distribution
System
Advanced Treatment for DPR
WWTP
Microfiltration
or
Ultrafiltration
Reverse
Osmosis
UV/AOP
Activated
Carbon
Ozone/BAC
“Engineered Storage” and
Monitoring
Concentrate
Disposal
WTP
The 4 “R’s” of Treatment for DPR
Redundancy
f(# of barriers
targeting a
contaminant)
Robustness
f(treatment process
diversity)
Resilience
f(failure response
protocols)
RELIABILITY
The bandwagon is tempting…
Proceed
Carefully!
Questions to ask before jumping
on the bandwagon
• What are relevant regulations?
• What are appropriate water quality
performance targets?
• What treatment schemes can be used?
• What monitoring is needed?
Questions to ask before jumping
on the bandwagon
•
•
•
•
What operations skills are needed?
How much will the project cost?
Are there other options?
Will the public support the project?
Texas Water Development Board
DPR Research Initiatives
• “Evaluating the Potential for Direct
Potable Reuse in Texas”
– Develop resource document for DPR
implementation
• “Testing Water Quality in a Municipal
Wastewater Effluent Treated to
Drinking Water Standards”
– Testing at CRMWD DPR facility
– Develop monitoring guidelines for DPR
National DPR Research Focus
Areas
•
•
•
•
•
•
Alternative treatment schemes
Blending and storage needs
Treatment operations and reliability
Monitoring strategies
Quality assurance
Public education and communication
Ellen McDonald, Ph.D., P.E.
817-806-1700
emcdonald@apaienv.com