Temporary Free Chlorine Conversion for Drinking Water
Information for public water systems about a temporary switch from chloramine to free chlorine and notification to consumers and TCEQ.
How Public Water Systems Disinfect Drinking Water
To protect public health, all public water systems (PWS) in Texas are required to disinfect drinking water before providing it to customers. Many PWSs use chloramine (free chlorine and ammonia), an effective disinfectant that persists over a long period of time, making it particularly valuable in areas with high temperatures.
Sometimes chloramine systems may need to complete a free chlorine conversion, where the system removes ammonia from the treatment process and only uses free chlorine to disinfect the water. This common practice is used as preventive maintenance to kill bacteria that, though harmless when consumed by humans, can introduce unwanted taste and odor, and create issues with maintaining a disinfectant residual. TCEQ'S regulatory guidance document, Public Water Systems: Temporary Conversions to Free Chlorine (RG-631), discusses how to perform a successful free chlorine conversion.
Notify Customers
Before starting the temporary treatment change, TCEQ recommends the PWS notify customers, including wholesale customers and their downstream customers. The notification should include information about the change, possible effects, and expected outcomes.
- Public Notice Template and Language: Chlorine Conversion
- Public Notice Template and Language: Chlorine Conversion Spanish
- Chlorine Conversion Facts (GI-466)
- Datos Sobre el Proceso de Conversión de Cloro Libre (GI-466 esp)
Notify TCEQ
Email TCEQ Water Supply Division 30 days before the start of the free-chlorine conversion. Include:
- PWS ID and name
- PWS contact name, title, and phone number
- Estimated start and end date
- PWS ID and names of customer systems
- Reason for the change in treatment
- Email the information to DBP@tceq.texas.gov
Assistance and Helpful Links
Information from EPA about chloramines in drinking water.
Controlling Nitrification in PWSs with Chloramines
How a PWS that uses chloramines can detect and respond to the degradation of the drinking water quality in a distribution system caused by nitrification.
Disinfection Byproducts in PWSs
What are disinfection byproducts, how are they formed, and how can PWSs control them.
Check the information TCEQ has for your PWS including chemical results, bacteriological results, sample schedules, violations, and contact information. This database is free and open to the public.
Financial, Managerial, and Technical (FMT) Assistance program
TCEQ offers FREE financial, managerial, and technical (FMT) assistance to help public water systems comply with regulations. Contact FMT for help with issues such as, but not limited to preventing operational problems, training about how to comply with rule requirements and performing capacity assessments.