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Validating Ultraviolet Disinfection for Public Water Systems

A public water system may get approval from the TCEQ to use an Ultraviolet (UV) disinfection system to inactivate pathogens. Manufacturers must test UV reactor models to ensure that they deliver the required UV dose established by the EPA.

Criteria for UV Light Reactors

A UV light reactor may meet the requirements for microbiological inactivation of Cryptosporidium, Giardia, and viruses if it meets these criteria:

  1. It must monitor and record flow rate, lamp status, UV intensity as measured by a UV sensor, and other parameters designated by the TCEQ.
  2. In lieu of a pilot study, the UV light reactors must undergo validation testing to determine the operating conditions under which it can deliver the required UV dose. The testing must follow the criteria established by the TCEQ and Title 40, Code of Federal Regulations, Section 141.720(d)(2) .
  3. It must be installed downstream of the filtration system.

For more information about these requirements see Title 30, Texas Administrative Code, Section 290.42(g)(5) .

To use a UV reactor for CryptosporidiumGiardia, and virus inactivation, you will need to request a UV-disinfection exception from TCEQ’s Technical Review & Oversight Team. Please see the External Guidance UV Disinfection for Pathogen Inactivation Credit for more information.

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UV Validation Tests and TCEQ Approval

Manufacturers must provide a validation testing report for each UV-reactor model they want to use in the state of Texas. Once the TCEQ approves a UV-reactor model, it may be used at any public water system in the state of Texas.

The validation testing must be conducted according to the criteria established by 40 CFR §141.720(d)(2) and the executive director. The validation study must include the following factors:

  • UV absorbance of the water;
  • Lamp fouling and aging;
  • Measurement uncertainty of on-line sensors;
  • UV dose distributions arising from the velocity profiles through the reactor;
  • Failure of UV lamps and other critical system components;
  • Inlet and outlet piping or channel configuration of the UV reactor;
  • Lamp and sensor locations; and
  • Other parameters determined by the executive director.

Validation testing must be conducted on a full-scale reactor that is essentially identical to the UV reactor(s) to be used by the system and using waters that are essentially identical in quality to the water to be treated by the UV reactor.

You can mail your validation report electronically to or mail a hardcopy to the following address:

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

Once approved by the TCEQ, a UV-reactor model will be posted on this website.

Contact Us

E-mail us at or call us at 512-239-4691.

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Approved UV Reactor Models

The following UV-reactor models have been approved for PWS use by the TCEQ:

•           Aquionics IL 450+

•           Aquionics IL 1000+

•           Aquionics IL 4000+

•           Aquionics IL 4500+

•           Aquionics IL 12000+

•           Aquionics IL 14000+

•           Calgon 12-inch Sentinel

•           Calgon 24-inch Sentinel

•           Calgon 48-inch Sentinel Chevron

•           ETS SX425-10

•           ETS SX635-16

•           ETS SX850-20

•           NeoTech Aqua Solutions D438

•           TrojanUVFlex 200

•           TrojanUVSwift 4L12

•           TrojanUVSwift 4L24

•           TrojanUVSwift 4L30

•           TrojanUVSwift 6L24

•           TrojanUVSwift 6L30

•           TrojanUVSwift 8L24

•           TrojanUVSwift 8L24-2L

•           TrojanUVSwift 8L30(S1)

•           TrojanUVSwift 8L30(S2)

•           TrojanUVSwift 10L30

•           TrojanUVSwift 10L30(S1)

•           VIQUA Pro30

•           VIQUA Pro50

•           Xylem/Wedeco Spektron 250e

•           Xylem/Wedeco Spektron 350e

•           Xylem/Wedeco Spektron 650e

•           Xylem/Wedeco Spektron 900e

•           Xylem/Wedeco Spektron 2000e

•           Xylem/Wedeco K143

The following table shows the current UV-disinfection systems with their TCEQ-approved credit values for pathogen inactivation.

Table of UV-Reactor Models Approved by TCEQ

UV Reactor
Make and Model
Log Inactivation
Date(s) Approved
Aquionics IL 450+ 0.5-log to 4.0-log January 4, 2016
Aquionics IL 1000+ 0.5-log to 4.0-log January 4, 2016
Aquionics IL 4000+ 0.5-log to 4.0-log January 4, 2016
Aquionics IL 4500+ 0.5-log to 4.0-log January 4, 2016
Aquionics IL 12000+ 0.5-log to 4.0-log January 4, 2016
Aquionics IL 14000+ 0.5-log to 4.0-log January 4, 2016
Calgon 12-inch Sentinel 1.0-log to 4.0-log February 15, 2017
Calgon 24-inch Sentinel 1.0-log to 4.0-log February 15, 2017
Calgon 48-inch Sentinel Chevron 1.0-log to 4.0-log February 15, 2017
ETS SX425-10 2.0-log to 4.0-log August 9, 2012
ETS SX635-16 1.0-log to 4.0-log December 22, 2014
ETS SX850-20 2.0-log to 4.0-log September 11, 2014
NeoTech Aqua Solutions D438 3.5-log to 4.0-log December 7, 2015
TrojanUVFlex 200 0.5-log to 6.0-log May 24, 2023
TrojanUVSwift 4L12 1.0-log to 4.0-log November 17, 2015
TrojanUVSwift 4L24 1.0-log to 4.0-log December 18, 2015
TrojanUVSwift 4L30 0.5-log to 4.0-log June 21, 2016
TrojanUVSwift 6L24 1.0-log to 4.0-log December 18, 2015
TrojanUVSwift 6L30 1.0-log to 4.0-log June 21, 2016
TrojanUVSwift 8L24 1.0-log to 4.0-log October 13, 2014
TrojanUVSwift 8L24-2L 1.0-log to 4.0-log October 14, 2014
TrojanUVSwift 8L30(S1) 1.0-log to 4.0-log July 25, 2016
TrojanUVSwift 8L30(S2) 0.5-log to 4.0-log November 15, 2016
TrojanUVSwift 10L30 1.0-log to 4.0-log October 31, 2014
TrojanUVSwift 10L30(S1) 1.0-log to 4.0-log June 21, 2016
VIQUA Pro30 4.0-log May 10, 2017
VIQUA Pro50 2.5-log to 3.0-log March 13, 2017
Xylem/Wedeco Spektron 250e 1.0-log to 4.0-log November 20, 2014
Xylem/Wedeco Spektron 350e 0.5-log to 4.0-log October 11, 2016
Xylem/Wedeco Spektron 650e 0.5-log to 4.0-log August 28, 2015
Xylem/Wedeco Spektron 900e 0.5-log to 4.0-log August 11, 2016
Xylem/Wedeco Spektron 2000e 0.5-log to 4.0-log December 21, 2016
Xylem/Wedeco K143 0.5-log to 5.5-log April 27, 2023

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