What makes Hamilton’s tap water world’s best-tasting?

Maybe it’s the alkalinity of Hamilton’s water that gives it the pleasant sweetness that has won it awards in recent years for being the world’s best-tasting municipal water from the tap. Or maybe it’s a treatment process — not used by other area water providers — that leaves the liquid with its refreshing, clean taste.

Hamilton tap water took home the gold in 2010 and 2015 for best in the world, plus first prize in 2009 for best in the country, and second in the world that year, from the Berkeley Springs International Water Tasting competition.

MORE: Half of Hamilton’s energy to come from water

Sprinkled in among those awards are others, like the Bronze Medal, awarded last month, for third best in the world at the Berkeley, W.Va., competition, which this year held its 27th annual event and is the world’s largest and longest-running taste comparison. The American Water Works Association also has given Hamilton it’s “Best of the Best” award at least three times for best-tasting municipal water in Ohio.

Curiously, the search for why Hamilton’s water tastes great begins in Fairfield — not Hamilton.

Fairfield is the site of Hamilton’s South Water Treatment Plant, at 5140 River Road, which was built in the 1950s and expanded during the 1990s. The original south water plant could produce only 6 million gallons per day. Hamilton bought well fields in what now is Fairfield shortly after World War II, when the federal government didn’t need the water.

The city’s north treatment plant, which isn’t now in operation because its capacity is not needed, also happens to be located outside city limits, in St. Clair Twp.

But the water-treatment process is entirely operated by the city of Hamilton’s utilities.

MORE: 8 start-up tech firms bring their ideas to Hamilton

“They produce some great water,” proclaims Jill Klein Rone, spokeswoman for the Berkeley Springs competition. “I know they’ve got a pretty interesting (treatment) system — I wish a lot of water companies could have that.”

John Bui (pronounced BOO-ey) is superintendent of the south treatment plant, which can process 40 million gallons per day, enough to fill Coney Island’s Sunlite Pool 11.4 times, but currently is producing 15.5 million to 16 million gallons daily, about half of it being sold to Butler County. Of the water consumed in Hamilton, about 65 percent is used by residents, and 35 percent by businesses.

When it’s a sweltering summer day, the water at the treatment plant looks very refreshing, but it leaves the enormous Great Miami Buried Valley Aquifer at 55 to 57 degrees. That’s cold enough that if someone stayed in the water for about two hours, they would suffer hypothermia, with death in only a few hours, according to medical experts.

The aquifer is an underground reservoir 200 to 250 feet below ground that extends as far as two miles from the Great Miami River in places.

RELATED: 5 facts about Great Miami Buried Valley Aquifer

The aquifer is “extremely valuable to this region,” Bui notes. It provides water for many municipal water utilities, including Cincinnati, Fairfield, Middletown and Dayton.

“The source we start out is pretty clean — it’s crystal clear,” Bui said. By contrast, if Hamilton used the river as its water source, treatment systems would have to use alum to precipitate out the fine solids before beginning its other treatment processes.

The water is so clean that when Environmental Protection Agency inspectors visit and see water cascading in the treatment plant’s aerator — the first stop in the treatment process, immediately from underground — they often “scoop the water right out of there, and taste it, and drink it, and say, ‘good water,’” Bui said.

“It is. It’s well water,” he added. “We test, we monitor for bacteria in the raw water. We don’t find any.”

For the most part, “We treat it for aesthetics, hardness,” Bui said. “If not, it would build up in pipes, and your appliances, hot-water heaters, for example.”

When water reaches consumers’ faucets, the pH is 8.9 to 9.0 on a scale of 0-14, with 7 being neutral. Alkaline water is coming into vogue, with some touting its health benefits.

“A lot of bottled water out there advertises, high pH, high-alkalinity water, but at 9, 9.1, we actually give it to you right here,” Bui said.

Hamilton has 12 total employers at the plant — six operators and four maintenance personnel, with Bui and a part-time administrative assistant.

RELATED: Hamilton water-cleaning startup may save money and lives

Hamilton has about 340 miles of water mains, ranging from 2 to 36 inches, with some more than a century old. It also has about 2,600 fire hydrants and 4,300 valves that must be regularly maneuvered and maintained.

Urged to reveal what makes Hamilton’s water tasty, Bui said, “The only difference that I can say is really the chlorine dioxide that is different from other water purveyors in this area.”’

The city has used chlorine dioxide since 1972. Most other utilities use chlorine gas as a disinfectant.

“Chlorine dioxide prevents taste and odors, and also won’t react with the organic materials in the water that generate carcinogens, like trihalomethanes, or haloacetic acids,” Bui said.

Treatment using chlorine dioxide is more complicated than chlorine gas, he said.

“It cannot be purchased and trucked in by tanker. It has to be manufactured on-site. It’s a little more sophisticated,” he said. “You have to have a lot of knowledge in operating generators to produce chlorine dioxide on site.”

Back in 2010, the first time Hamilton was named best in the world, “One of the judges said that Hamilton water was ‘pleasantly sweet.’” Bui said. “So ever since, I use that, and joke around with my colleagues, that, ‘Yeah, I put a dash of Splenda in.’”

About the Author