NORTHWEST HARRIS COUNTY MUNICIPAL UTILITY DISTRICT 5 will begin using a different process of water disinfection in your subdivision on or about March 18, 2024. This process involves using chloramines rather than only chlorine as the disinfectant in the water supply.

The use of chloramines rather than chlorine is not new technology as it is in widespread use in many cities and other drinking water supplies. The change is intended to benefit our customers by reducing the levels of disinfection byproducts (DBPs) in the system, while providing protection from waterborne disease. The City of Houston has been treating its water with chloramines for over twenty years. Water containing chloramines is perfectly safe for drinking, bathing, cooking, and most other uses we have for water. HOWEVER, there are two categories of people who need to take special care with chloraminated water:

  • Kidney Dialysis Patients
    The change to chloramines can cause problems to persons dependent on dialysis machines. A condition known as hemolytic anemia can occur if the disinfectant is not completely removed from the water that is used for the dialysate. Consequently, the pretreatment scheme used for the dialysis units must include some means, such as a charcoal filter, for removing the chloramines prior to the conversion to chloramines. Medical facilities should also determine if additional precautions are required for other medical equipment.
  • Live Fish or Other Aquatic Animal Owners
    Chloraminated water may be toxic to fish. If you have a fish tank, please make sure that the chemicals or filters that you are using are designed for use in water that has been treated with chloramines. You may also need to change the type of filter that you use for the fish tank.

Following are answers to frequently asked questions you may have:

  • What is the current drinking water disinfection method?
    The current method of disinfection used by the Northwest Harris County MUD 5 is chlorination. Chlorine is added to drinking water at a controlled level. Chlorine is an effective disinfectant of many kinds of bacteria that may be harmful to one’s health. The District’s drinking water has met State and Federal standards for bacterial control for many years.
  • What is chloramination?
    Chloramination is the use of both ammonia and chlorine to disinfect water. Ammonia is added to water at a carefully controlled level. The chlorine and ammonia react chemically to produce a combined chlorine residual or chloramines. Chloramines are safe in drinking water and serve as an effective method of disinfection. In the U.S., many water systems have used chloramination for several decades.

How can I get more information?

Feel free to contact the Northwest Harris County MUD 5 Operator, Municipal District Services at (281) 290-6500 or visit should you have a question or comment.