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Membrane Challenge Studies and Cartridge Filter Systems

Public water systems with membrane and cartridge filtration systems for removing Cryptosporidium and Giardia must receive approval from the TCEQ to evaluate each membrane’s ability to remove pathogens. The membrane filtration systems impacted by this requirement are those that were installed or replaced after April 1, 2012.

Public water systems must conduct challenge testing for membrane and cartridge filtration systems that are installed to remove Cryptosporidium and Giardia. These tests evaluate how efficiently each membrane model or cartridge filter system removes pathogens and allows the TCEQ to establish a log removal value (LRVC-Test).

Membrane and cartridge filter manufacturers must provide a non-destructive performance test (NDPT) and quality control release value (QCRV). The NDPT and QCRV help verify that all manufactured membrane models and cartridge filter systems that were not subject to challenge testing in the past will achieve at least the same log removal level as more current membrane models and cartridge filter systems that were challenge-tested.

Public water systems with membrane filtration systems will be approved for a removal-credit based on the lower of the LRVC-Test and the log removal value that can be verified through direct integrity testing (LRVDIT).

Challenge studies for the following membrane models and cartridge filter models for Cryptosporidium and Giardia removal have been reviewed and approved by the TCEQ:


Membrane Models


Cartridge Filter Models


Membrane Systems

The following table shows the current membrane systems with their TCEQ-approved credit values for pathogen removal:

Make and Model 

and Giardia
Log Removal 

 Date(s) Approved 
by TCEQ 

 BASF Inge d5000  4.5, deposition mode  October 21, 2015
 BASF Inge dizzer  6.2, deposition mode  November 14, 2017
 Dow UF-SFD2880   3.76  August 3, 2012
 Dow IntegraFlo DW102-1100  6.3, deposition mode  March 11, 2015
 Dow IntegraFlux SFD-2880XP  6.15, deposition mode  July 18, 2016
 Evoqua Memcor L40N  6.14, deposition mode  September 13, 2016  


 ZeeWeed 700B-8060/UF10

 ZeeWeed 700B-10060

 5.41, deposition mode

 for each module

 September 7, 2017


 ZeeWeed 500D 

 6.2, deposition mode 

 6.1, feed-and-bleed mode 

 January 27, 2014 
 Koch Targa II UF  4.6  June 26, 2013
 Koch Puron MP UF  5.6, deposition mode  November 28, 2017
 Nanostone CM-151 UF Ceramic  5.31, deposition mode  January 31, 2018
 Pall Microza 620A MF   5.68   March 20, 2013 
 Pentair X-Flow Aquaflex HP and Xiga HP  4.95, deposition mode  November 5, 2015
 Pentair X-Flow Aquaflex and Xiga  4.95, deposition mode  May 26, 2016
 Scinor SMT 600-P50 and SMT 600-P80  6.26, deposition mode  August 21, 2015
 Siemens Memcor - UF Elements
 L20N and L10N
 6.27  April 26, 2013
 Siemens S10N UF   5.03   October 23, 2013 
 Toray HFU-2020N UF  4.7, deposition mode  May 28, 2014


Cartridge Filter Systems

The following table shows the current cartridge filter systems with their TCEQ-approved credit values for pathogen removal:

Cartridge Filter

Make and Model


Log Removal


Log Removal

 Date(s) Approved  


Graver          QCR II



3.0, Bin 1

3.4, Bin 2, Bin 3, Bin 4

 (3.4 each cartridge filter,

 7.3 maximum for two in series) 

April 18,


Harmsco   HC/170-LT2



 3.0, Bin 1

 3.1, Bin 2, Bin 3, Bin 4

 (3.1 each cartridge filter,

 6.7 maximum for two in series) 

January 18,


Any manufacturer seeking to distribute a membrane or cartridge filter in the state of Texas must send the challenge study for the particular model to TCEQ for review and approval prior to installation. Challenge studies may be mailed to the following address:

Texas Commission on Environmental Quality
Technical Review & Oversight Team (MC-159)
PO Box 13087
Austin TX 78711-3087

For more information about these requirements see Title 30, Texas Administrative Code, Section 290.42(g)(2)-(3).Exit the TCEQ

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