Map of North Texas Municipal Water District

Map detailing the outlines of the North Texas Municipal Water District coverage area.

The North Texas Municipal Water District, which serves approximately 80 cities and communities in a 2,000-square-mile area across 10 counties, has begun its annual temporary disinfectant process change, colloquially referred to as a “chlorine burnout.”

Rockwall County receives water exclusively from the NTMWD, and a significant portion of southern Hunt County is served by the district as well.

The annual system maintenance was scheduled to begin Monday and continue through the end of the month

The district issued the following information regarding the process:

Disinfection is a critical part of water treatment to keep water safe. During NTMWD’s normal water treatment processes, disinfection is a two-step process that first treats the water at the plant and second adds disinfectant to maintain water quality as it travels long distances through pipes to homes and businesses. Both steps are needed to keep tap water free of harmful microorganisms, such as parasites and viruses.

NTMWD uses a combination of ozone and free chlorine (first step) to disinfect water at the treatment plant and then adds chloramine, which is chlorine + ammonia (second step) before leaving the plant. This maintains required water disinfection levels from the time it leaves the treatment plant all the way to your tap. According to the Texas Commission on Environmental Quality (TCEQ): “Treatment prior to distribution may utilize a number of different disinfectants, but a public water system is required to use either chlorine or chloramine in the distribution system.”

Each spring for about one month, we suspend the typical use of ammonia to allow the remaining chlorine to keep the water disinfected as it travels through the system. This temporary change in disinfectant helps maintain the system and high water quality year round. It’s important to do this before summer because hotter temperatures can increase the potential for bacterial growth in pipes.

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