Westerville officials are cautiously optimistic that the city's water woes are finally over.

Westerville officials are cautiously optimistic that the city's water woes are finally over.

Thanks to the debut of Westerville's updated water treatment plant a few months ago, officials hope to receive their first passing grade from the Ohio Environmental Protection Agency in a year.

During testing for the third and fourth quarters of 2015 and the first quarter of 2016, levels of total trihalomethanes -- a byproduct of added chlorine -- were about 0.09 milligram per liter at one of four testing sites in the city. The EPA benchmark is 0.08.

The EPA directs municipalities to inform their residents when the average of the last four months is over 0.08, regardless of the concentration at the time of testing.

The levels aren't considered dangerous unless consumed over long periods of time, something city leaders emphasized at the time.

"The most important fact is this: City water remains safe to drink," City Manager David Collinsworth said.

But the plant was already scheduled to add new step in the city's process, a granular activated carbon filtration system that sifts the water through a fine, sand-like layer of carbon, removing most TTHMs.

While the city has yet to see official test results from the EPA, Water Utility Manager Richard Lorenz said his team tested the southeast site -- where the TTHMs were most concentrated -- and said the number has fallen all the way down to about 0.02 milligram per liter.

"The numbers were way down, as expected," he said. "So the treatment is working, and we're pretty happy with it."

Lorenz credits the city for spending nearly $12 million on the new plant, which had a grand opening ceremony at Westerville's annual Party at the Creek, Thursday, May 26.

At the ceremony, Collinsworth thanked residents for their support, and said the $13.5 million spent on the project served an important purpose.

He said that while, "$13.5 million may sound like a lot of money," the city had "many more expensive options."

Lorenz has consistently thanked residents as well, and said in some cities, that figure may have been too much. But he said Westerville has forward-thinking residents, who helped clean their own water with the support.

"We're very pleased that our community supports investment in the drinking water," he said. "The improved water quality is the end result."

The water department expects to have EPA results back soon. While it's likely the numbers will be so low this quarter that they will dip below the average for the entire last year, Lorenz isn't taking the result for granted just yet.

"I'm a little bit leery to say that everything is OK because I'm not the final word," he said.

"I don't want to usurp the Ohio EPA."