From The Editor | August 1, 2016

How To Treat The Best-Tasting Tap Water

Peter Chawaga - editor

By Peter Chawaga

It may seem counter-intuitive to judge tap water based on how it tastes. After all, most consumers prefer that their water remains flavorless and consider any tang a reason for concern.

Flavored tap water can indicate contamination in the supply, disorder at the treatment plant, or worse. But sometimes, the flavor of tap water indicates the hard work and success of the utility that’s providing it.

The American Water Works Association (AWWA) seeks to reward utilities with particularly good-tasting water every year during a taste test at its annual conference and exhibition. By drawing attention to the work that members and attendees put into the product they provide customers, the contest can change the narrative about how tap water should taste and provide an example to other utilities about how to treat influent into a winning product.

“Water that tastes good and is safe for consumption are the primary goals for all water providers,” said Deirdre Mueller, public affairs manager for AWWA. “Successfully achieving those goals means happy and healthy customers. It also means that the utility is meeting its mission and deserves to be recognized for that accomplishment.”

This year, the City of Bloomington, MN, was crowned the taste test winner. Its water was found to be the most crisp, refreshing, and free of unsavory tastes, odors, or coloring by a panel of judges.

One judge, Cliff Shrive, summarized the qualities that separate a winner from the rest of the field.

“I look for water that has little to no smell and that doesn’t have an aftertaste,” he said. “The waters that are really good will not feel flat and the best ones leave you wanting another drink. It really is a combination of smell, feel, and taste that will differentiate a good water from the best water.”

Curious about how its water would compare with peers, Bloomington entered AWWA’s “Best in Glass” competition at a Minnesota-section conference in Duluth, MN, in the fall of 2015. There, it won first place and was entered into the national competition.

“It was a great honor for our water to be held in such high regard,” said Craig Haskins, senior utility operator for the Bloomington treatment plant.

Bloomington pulls raw water with a hardness around 320 ppm from six deep wells at the Jordan and Mt. Simon-Hinckley aquifers, according to Haskins. They add slaked quicklime to precipitate the groundwater’s calcium and magnesium, which account for the water’s hardness. They add carbon dioxide to adjust the pH levels, combine chlorine with naturally-accruing ammonia to disinfect, and add fluoride to protect teeth. The result is water that’s been reduced to a hardness of 90 or 95 ppm. The plant maintains a laboratory where operators run several tests each day to ensure standards are met.

“The staff makes a conscientious effort to do what is best and are very prideful of the quality of water being served to Bloomington residents and businesses,” Haskins said. “At the end of the day, it comes down to the diligent shift operators who sacrifice their weekends, holidays, and time with family to ensure the residents of Bloomington receive clean, safe, and excellent-tasting drinking water.”

AWWA has found that in this way, Bloomington is typical of other plants producing great-tasting water. Finalists over the last few years have pulled from groundwater and surface water in equal numbers and utilized a range of treatment technologies or none at all. But each one has depended on people making the best decisions for their end-product.

“I did a survey of the source water and treatment technology used by our top finishers over the past couple of years and there isn’t a clear pattern,” said Mueller. “This tells me that all treatment technologies work and drinking water quality depends on using the right technology effectively and in the right environment. The operators and water quality employees who make and implement those technology decisions are really the ones who make the difference in the quality of the final product.”

In providing a lesson for operations that want to emulate Bloomington’s success, Haskins is succinct.

“I think the best advice I could give to other plants is to never settle for the status quo,” he said. “It is important to always look at your process and see what you can do better.”