You might notice a slight change to the taste or smell of your tap water this spring. This change is due to a temporary change in disinfectant used by Allen’s water supplier, North Texas Municipal Water District (NTMWD). Though your water might taste or smell different, it’s safe for drinking and bathing.
During most of the year, NTMWD uses a mixture of chlorine and ammonia to maintain the pipes, tanks and towers that carry and store our water. For four weeks every year, NTMWD removes the ammonia and uses chlorine only. This temporary change takes advantage of chlorine’s effectiveness at eliminating microorganisms to give our water system a "deep cleaning."
NTMWD does not increase the amount of chlorine in the water during this four-week change. However, tastes or smells can become more prominent when ammonia is removed. Outdoor temperatures and overall water use can also influence the reaction of chlorine to other materials in the water supply, causing smells and odors to fluctuate year to year.
Not everyone notices a change in the water during this period. However, those who may notice the changes can reduce chlorine tastes and odors by running tap water a few minutes before using, refrigerating water in an open pitcher for several hours or installing filters on faucets. While not necessary to meet safety standards, whole-home filtration systems can also help reduce tastes and odors.
This annual maintenance process, along with every treatment used by NTMWD, meets federal safety criteria created by the Environmental Protection Agency. Thousands of tests to assure water quality are performed annually by NTMWD, the City of Allen and the Texas Commission on Environmental Quality (TCEQ). These tests verify that Allen’s water supply meets all federal and state requirements for health and safety. In fact, the City of Allen is rated as a "Superior Water System," the highest level possible.
TCEQ allows water systems to use a number of different treatments before distributing water, but public water systems are required to use either chlorine or chloramine in the distribution system.
In February, Allen water utility customers were mailed an informational flyer about this temporary change. You can find annual water quality reports, water safety resources and information on sampling and testing at CityofAllen.org/SafeWater.