Frequently Asked Questions

Each spring for about one month, NTMWD temporarily changes the disinfectant used in the second step of water treatment. This is necessary to help maintain the system and high water quality year-round. During this time, ammonia is temporarily suspended and only chlorine is used to maintain water disinfection from the time it leaves the treatment plant as it travels long distances to the tap. Chlorine levels in the water are consistent with year-round operations. However, the discontinuation of ammonia can make the presence of chlorine more noticeable. Cities may help with this process by flushing water out of fire hydrants during this time, which helps move the chlorine through the system faster. The EPA estimates up to 40% of water providers who use chloramine conduct this process.

No, test results verified by the TCEQ show chlorine levels during the temporary change in disinfectant process are consistent with normal year-round operations.

No, it's actually a preventive measure that helps prevent bacteria from growing in pipes. According to the TCEQ (PDF), many utilities in areas with warmer climates throughout the state and country that use chloramines for their distribution conduct the same process. NTMWD has performed this routine process for over 10 years and maintained high water quality each year.

NTMWD does not plan to discontinue this safe and accepted practice. Discontinuing this process would require different and more costly operational practices in the distribution systems, such as increased fire hydrant flushing which would reduce available water supply and could impact our ability to meet water demand and provide adequate flows for fire-fighting in the summer months. In order to do this, we would need additional water supplies above and beyond those being planned.

It's important to do this before summer because hotter temperatures can increase the potential for bacterial growth in pipes. Moving the water through the system faster by flushing it through fire hydrants can help reduce chlorine odor and taste. Conducting this flushing of pipes in the spring also helps conserve valuable water by reducing the amount of flushing needed during the warm summer months when water demands increase due to irrigation.

It is our understanding that Dallas Water Utilities is able to maintain its system through a comprehensive flushing program. However, based on NTMWD's expansive system serving nearly 80 communities across North Texas, maintenance solely through flushing is not a viable or cost-effective option for our unique regional system.