HARLINGEN – A Harlingen woman said she notices an odor resembling harsh chemicals when she turns on the faucet.

Harlingen resident Sandra Saenz said her community is her little slice of heaven.

"It's quite peaceful, not a lot of traffic, and everybody keeps to themselves," she said.

Saenz said a few weeks ago, she and her neighbors received notices from Harlingen Waterworks System. She told CHANNEL 5 NEWS the notices stated for the month of October, the company was to start changing the way they treat the water.

According to the notices, the water is normally treated with a mixture ammonia and chlorine. However, this month only, chlorine will be used to restore the efficiency of the normal treatment process.

Saenz said she isn't a fan.

"Now that they took the ammonia out, you can definitely taste the chlorine and I don't like it," the resident explained.

Saenz said the odor of the water is also different. She told CHANNEL 5 NEWS it resembles harsh chemicals. As an asthmatic, she said, she is extra sensitive to chemicals. As a result, her daily routine has changed.

"I'm a tap water girl. I drink tap, bottled, whatever's available. Now, I won’t even touch the tap," Saenz said.

CHANNEL 5 NEWS reached out to Harlingen Waterworks System general manager Tim Skoglund. He was unavailable for an on-camera interview but told us 25,700 customers and nine public water systems received the notice.

We asked what role ammonia plays in water treatment. He explained when combined with chlorine, ammonia creates a disinfectant named monochloramine. He added monochloramine is a more effective disinfectant than chlorine alone.

 He said a mild change in the taste, odor or color of the water is possible when the water is treated with only chlorine, either of which is no reason for concern. He also said the public water supply for approximately 80 percent of the U.S. population is disinfected using chlorine only.

Skoglund said customers are welcome to call customer service at 956-430-6100 to report concerns about changes in the quality of their water.  Additional information can be found on our website at www.hwws.com.

CHANNEL 5 NEWS wanted to know if drinking water treated with only chlorine posed any risk to Harlingen residents. Brian McGovern with the Texas Commission on Environmental Quality sent us the following statement, which reads in part: 

"Temporary conversion to free chlorine, in conjuction with distribution line flushing, has been shown to be an effective strategy to improve water quality. While chemicals like chlorine could be harmful in high doses, when they are properly added to the water, they result in low concentrations that kill germs but are still safe to drink. If used properly, there should be no detrimental impacts to customers."