This document summarizes Texas regulations regarding membrane filtration facilities for drinking water treatment. It outlines piloting requirements, current pathogen removal credits for different membrane types and pretreatment, Long Term 2 Enhanced Surface Water Treatment Rule bin classifications and additional Cryptosporidium treatment requirements. It also discusses membrane removal credit and challenge testing requirements, direct integrity testing, and indirect integrity monitoring. The conclusions state that membrane filtration is an approved innovative treatment process in Texas, with piloting and monitoring requirements changing to comply with LT2ESWTR regulations.

1. LT2ESWTR and Membrane
Filtration in Texas

2. Proposed Membrane
Filtration Facilities
Reviewed under §290.42(g) as
innovative treatment techniques and
exceptions to the Rules

3. Piloting Requirements
90 days
Pilot study protocol (site specific)
Pilot study report (site specific)
Exception from piloting - may submit
pilot or full-scale data from a similar or
worse raw water source

4. Current removal credits
MF, UF, NF & RO
No pretreatment
2.0-log cryptosporidium (crypto)
3.0-log giardia
0.0-log virus
Note: April 1, 2012 replacement and new
installations will require challenge testing

5. Current removal credits
(cont)
MF, UF, NF & RO
coagulation & flocculation only
2.0-log crypto
3.0-log giardia
1.0-log virus
Note: April 1, 2012 replacement and new
installations will require challenge testing

6. Current removal credits
(cont)
MF, UF, NF & RO
coagulation, flocculation and clarification
2.0-log crypto
3.0-log giardia
2.0-log virus
Note: April 1, 2012 replacement and
new installations will require challenge
testing

7. LT2 Bin Classifications
Bin 1 Less than 0.075 ocysts/L
Bin 2 Greater than 0.075, but
less than 1.0 oocysts/L
Bin 3 1.0 to less than 3.0
oocysts/L
Bin 4 3.0 or higher oocysts/L

8. Additional Cryptosporidium
treatment requirements
Conventional Treatment1
Bin 1 Systems None
Bin 2 Systems 1-Log
Bin 3 Systems 2-Log
Bin 4 Systems 2.5-Log
1Conventional treatment = coagulation/flocculation,
clarification and media filtration.

9. Membrane filtration
removal credit (LT2)
Credit = removal efficiency
demonstrated in challenge test
Must be supported by direct
integrity testing
Up to 6-log removal credit

10. Membrane removal credit
is the lesser of
The log removal value (LRV)
demonstrated during challenge testing
(LRVCT), or
The log removal value that can be
verified through direct integrity testing
(LRVDIT)

11. Challenge Testing
A full scale (or small scale)
membrane module test conducted to
determine the removal value (LRV)
of a membrane material for a
particular organism

12. Information provided by
the challenge test
Establishes a removal efficiency for each
membrane module tested (LRVCT)
Provides a performance characteristic
(QCRV) such that when applied to
unchallenged membranes in the same
product line, demonstrates there are no
pores (or defects) larger than 3 μm

13. Direct integrity test (DIT)
A non-destructive performance test
applied to a membrane unit to identify
and/or isolate integrity breaches

14. Direct integrity test (DIT)
Verifies the treatment credit awarded
to the membrane system by the State
Must have a resolution of 3 μm, or less
Conducted daily under LT2
(currently 1/wk min and after CIP)

15. Indirect integrity
monitoring
Continuous monitoring of each rack of
modules with laser turbidimeter or
particle counter
Other methods may be accepted after
TCEQ approval

16. House Bill 2654
Class I Injection Wells
Non-hazardous brine from
desalination operations or,
Non-hazardous drinking water
treatment residuals

17. Conclusions
Membrane filtration is approved in
Texas as an innovative or alternative
treatment process
Piloting, pathogen removal credits and
monitoring requirements have
changed as rules were adopted to
comply with LT2ESWTR

18. TCEQ PDW Section
Contacts
Marlo Wanielista Berg, P.E. (512) 239-6967
James (Red) Weddell, P.E. (325) 481-8056
Sylvana (Sam) Turner (409) 899-8798
Jack Schulze, P.E. (512) 239- 6046
Reyna Miner, P.E. (512) 239-6183