The document discusses wastewater reuse in Texas. It outlines various wastewater reuse activities like irrigation, construction uses, and industrial processes. It also summarizes the regulatory framework for direct potable reuse established by the Texas Commission on Environmental Quality. Several water systems in Texas are highlighted that treat wastewater through multi-barrier treatment trains incorporating microfiltration, reverse osmosis, ultraviolet disinfection, and blending to indirectly produce drinking water from wastewater. Lessons learned are discussed around the regulatory and operational commitment required for direct potable reuse.

1. Reuse
in
Texas
Linda Brookins, Division Director
Water Supply Division
Texas Commission on Environmental
Quality

2. Wastewater
Reuse

3. Wastewater Reuse
• Wastewater reuse is a water management and
conservation tool.
• Reuse activities:
•WWTP on-site use
• Irrigation
•Construction: dust suppression/soil compaction
•Industrial processes
•Impoundment/pond maintenance
•Fire protection
•Hydraulic fracturing
3 September 9, 2014

4. Wastewater Reuse (cont.)
• TCEQ has issued rules authorizing wastewater
reuse:
•Domestic wastewater
• Satellite reclamation facilities
•Graywater
•Industrial wastewater.
4 September 9, 2014

5. Direct Potable
Reuse

6. 6 September 9, 2014

7. 7 September 9, 2014

8. Direct Potable Reuse in Texas
• Two plants in operation
•Colorado River Municipal Water District
•City of Wichita Falls
•No environmental buffers
•Both have blending
• One with construction approval
• City of Brownwood
• Several PWSs are investigating the use of DPR
8 September 9, 2014

9. Regulatory Framework
• TCEQ has design criteria rules for PWS design
• TCEQ also allows “exceptions”
• DPR approved using an exception for the source
of water
• Not groundwater or surface water
•WW effluent as a source
• Granted exceptions provide conditions for site
specific design, operation, maintenance, and
reporting requirements
• Exceptions granted based on site specific data
• Pilot studies
• Full scale verification testing
9 September 9, 2014

10. Developing criteria without rules
• Started with US EPA SDWA
• Multi-barrier approach
• Chemicals
• Pathogens
• Pathogens
• Find EPA acceptable drinking water concentrations
• Find maximum influent concentrations (WW effluent)
•Determine log treatment required
• Use SWTR to determine operating & reporting criteria
• Chemicals
• No jurisdiction to regulated unregulated chemicals
• Barriers treat for both regulated and unregulated
chemicals
10 September 9, 2014

11. Proposed Wichita Falls
Removal / Inactivation
Treatments
TCEQ Approved Log Removal /
Inactivation Log Credits for
Individual Treatment Processes
Proposed Brownwood
Removal / Inactivation
Treatments
TCEQ Approved Log Removal / Inactivation Log
Credits for Individual Treatment Processes CRMWD Reclaim WTP
Removal / Inactivation
Treatments
TCEQ Approved Log Removal /
Inactivation Log Credits for
Individual Treatment Processes
Virus Giardia Crypto
Virus Giardia Crypto Virus Giardia Crypto
DZ 1: Pre-formed
Monochloramine
1.11 0.64 NA
DZ 1: Free chlorine 4.2 0.15 NA
Free chlorine NA NA NA
2008 SWTP’s Coagulation,
Flocculation and
Clarification
0.5 0.5 0.5
DZ 2: Monochloramine 0.70 0.40 NA DZ 2: Free chlorine 5.0 0.18 NA
2008 MF Membranes 1.5 2.8 2.8 UF Membranes NA 3.76 3.76 MF Membranes NA 4.0 4.0
DZ 3: Monochloramine 0.02 0.01 NA
DZ 3: Primary UV
Disinfection
NA 2.2 2.2
Advanced oxidation (UV
w/hydrogen peroxide)
2.0 4.0 4.0
DZ 4: Chloramines NA NA NA
Advanced oxidation (UV
w/hydrogen peroxide)
2.0 4.0 4.0
2008 RO Membranes
(chemical removal)
NA NA NA
RO Membranes
(chemical removal) NA NA NA
RO Membranes (chemical
removal) NA NA NA
Blended 50% reclaimed
WWTP effluent to 50%
surface water (possible
chemical and pathogen
reduction)
NA NA NA No blending with any raw source waters
Blended 20% reclaimed
WWTP effluent to 80%
surface water (possible
chemical and pathogen
reduction)
NA NA NA
2010 SWTP’S Coagulation,
Flocculation and
Clarification
0.5 0.5 0.5
Activated Carbon
Adsorption (chemical
removal)
NA NA NA
Blended flow treated at 5-
SWTPs
(coagulation, flocculation,
clarification, & disinfection)
4.0 3.0 3.0
2010 Gravity Filters 1.5 2.5 2.5
2010 Gravity Filters w/CFE
< 0.15 NTU
NA (+0.5) (+0.5)
2010 Gravity Filters w/IFE
< 0.15 NTU
NA (+1.0) (+1.0)
DZ 4: Monochloramine 0.73 0.42 NA
DZ 4: Secondary UV
Disinfection NA 4.0 4.0
DZ 5: Monochloramine 2.64 1.53 0.0 DZ 5: Chloramines 0.17 0.14 NA
Total Log Removal /
Inactivation Credits at 12o
C
9.2
9.3
(9.8 or
10.3)
6.3
(6.8 or
7.3)
Total Log Removal /
Inactivation Credits at 5o
C
9.37 10.43 9.96
Total Log Removal /
Inactivation Credits at 5o C
8.00 15.0 15.0
TCEQ Minimum Required
Removal / Inactivation
9.0 7.0 5.5
TCEQ Minimum
Required Removal /
Inactivation
8.0 6.0 5.5
TCEQ Minimum Required
Removal / Inactivation
8.0 6.0 5.5

12. City of Wichita Falls Monitoring Locations, Frequency, and Action Levels
RRWWTP
before CL2 Contact Basin
Monochlor. – cont. < 1.0 mg/L (when Temp > 16C)
Monochlor. – cont. < 1.5 mg/L (when Temp  16C)
ClO2 - Must meet CT
ClO2 – 8hr
pH, Temp & Flow – 8 hour
RRWWTP
Sed Basin
MF Membranes
Individual RO Units
Salt Rejection – 8 hr > 10% yesterday
Salt Rejection – Average month > 5%
Conductivity – 8 hr > 20% unit average
Nitrate – 8 hr ≥ 10 mg/L
Finished Water Effluent – Entry Point
Nitrate/Nitrite – weekly > MCLs
E. coli – weekly > 0 CFU/L
Giardia – 2x monthly (fast response) > 0
Crypto – 2x monthly (fast response) > 0
Virus – 2x monthly > 0
MCL/SCL chemicals > MCLs
Sed Basin
Turbidity - 8 hours
City of
Wichita Falls
Lakes
RRWWTP before CL2 Contact Basin
Turbidity–continuous ≥ 24 NTU
E. Coli–daily ≥ 15K C&G; ≥ 30K Task Force
Individual MF Units
DIT – daily  Fail
IFE turbidity – 5 min > 0.100 NTU
DIT after CIP  Fail
Reverse Osmosis
Blend
Sed Basin
Media Filter
Chloramine
Contact
D1 - Must meet CT
Monochloramine – 8 hour
pH, Temp & Flow – 8 hour
Sed Basin
Turbidity – 8 hours
D5 – EP Must meet CT
Total Cl2 – continuously
pH, Temp & Flow – 8hr
Individual Media Filters
Turbidity – 15 minutes > 0.3 NTU
& 95% > 0.15 NTU
D2 - Must meet CT
Monochloramine – 8 hour
pH, Temp & Flow – 8 hour
D3- Must meet CT
Monochloramine – 8 hour
pH, Temp & Flow – 8 hour
D4– 36J Must meet CT
Total Chlorine – 8 hour
Temp & Flow – 8 hour
Blended water
Turb & Alkalinity - 8 hrs
End of D1
Turb & Alkalinity – 8 hrs
RRWWTP after CL2 Contact Basin
Giardia – monthly > 700 cysts/L
Crypto – monthly > 9.5 oocysts/L
Virus - monthly > 22 virus/L
E. Coli – daily >75 MPN/100 mL
TOC & Alkalinity - monthly
D4 - for CT
pH – 8 hour
D5
10 MG % full – 2 hr < 50%
Blend
Reuse/Lake Ratio - 15 min.  55%
Average Ratio – 2 hrs  50.00%
Combined Media Filters
Turb – 4 hs > 0.3 NTU

13. Advice for interested systems
• Know your source water
• Wastewater permits are for aquatic health, not human
consumption
• Test for pathogens
• Test for chemicals
•Worst case and seasonal variability
• Pretreatment programs
• Know your public
• Inform and educate
• Know your treatment
• Instantaneous monitoring results when possible
• Shut downs and alarms for critical points
•What can you do with any wastes
• Try it out
• First without water going to the public
•Road test operating procedures with the operators
13 September 9, 2014

14. Lessons Learned
• DPR is a HUGEcommitment
• For
•Regulatory agency
• Public water system
• Using dollars and time
• During development
•During lifetime of operation
• DPR is not for every system
14 September 9, 2014

15. Lessons Learned
• Things go wrong
• Responding right protects public health
• Importance of monitoring and shut-down triggers
• Procedures and methods to investigate, solve, and
prevent further problems
• Plan for a “back up” if you lose a barrier
• Plan during shut downs with no water
• What do you do
• How do you communicate to the public
15 September 9, 2014

16. Lessons Learned
• For regulators being 0n-site at the PWS is key
• Helped TCEQ and helped the system
• Engaging with the operators
• What can go wrong and what can be fixed
• Having a team with a variety of experience and
expertise to address issues as they arise
• Being able to provide ALL resources at a system
with no water – including staff
16 September 9, 2014

17. Lessons Learned
• Research and education is key
• TCEQ confirms each DPR project is unique and
requires site specific criteria
• With its scientific research (WateReuse)
• With its experience with treatment used
17 September 9, 2014

18. Colorado River
Municipal
Water District

19. Colorado River Municipal Water
District
19 September 9, 2014

20. CRMWD Pathogen and Chemical
Treatment Credits
Subsequent PWS SWTPs
Microfiltration Reverse Osmosis Sedimentation
20 September 9, 2014
Advanced Oxidation Granular
with Ultraviolet light Media Filtration
Chemical Removal
4-log Crypto
4-log Giardia
e
n
d
w
i
t
h
L
a
k
e
W
a
t
e
r
8-log Crypto 3-log Crypto
8-log Giardia
4-log Virus
Chemical Treatment
3-log Giardia
4-log Virus

21. 21 September 9, 2014

22. 22 September 9, 2014

23. City of
Brownwood

24. City of Brownwood – Proposed

25. City of Wichita
Falls

26. 26 September 9, 2014

27. City of Wichita Falls
Disinfection Sedimentation Microfiltration Reverse Osmosis Sedimentation Granular
Membranes Media Filtration
0.5-log - Cypto 2.8-log - Crytpo
0.5-log - Giardia 2.8-log - Giardia
* Minimum total Giardia and Virus inactivation during FSVT1
4.0-log Giardia
2.0-log Virus
Disinfection
5.6-log* - Giardia
8.9-log* - Virus
L
a
k
e
B
l
e
n
d
4.0-log Crypto

28. 28 September 9, 2014

29. 29 September 9, 2014

30. 30 September 9, 2014

31. Contact:
Linda Brookings, Division Director
Water Supply Division
Texas Commission on
Environmental Quality
linda.brookins@tceq.texas.gov
512-239-4625