Process filters Grand Lake water

CELINA - A Cincinnati firm has won a national award for its contributions to a new process that filters water from Grand Lake to provide drinking water for the city's 10,000-plus residents.

The new process went online last year at Celina's water treatment plant on U.S. 127. The 13,500-acre lake is Celina's sole source of drinking water.

The water plant upgrades are intended to boost the plant's efficiency, reduce operational costs and position it to meet any new Ohio Environmental Protection Agency water-quality standards for the foreseeable future.

Hazen and Sawyer earned a National Recognition Award for exemplary achievement in the American Council of Engineering Companies' 55th annual Engineering Excellence Awards, according to a ACEC news release.

The firm, which specializes in providing safe drinking water, was acknowledged for designing the dissolved air flotation (DAF) bioreactor upgrade and rehabilitating one of the plant's clarifier tanks for biological treatment of DAF residuals containing cyanobacteria, more commonly referred to as blue-green algae. The algae can produce toxins that are harmful to small animals and humans.

"This innovative approach allows for continued land applications of the residuals and supports further research on treatment of problematic source waters prone to harmful algal blooms," according to the release. "The project has helped Celina reduce its costly use of treatment process chemicals, producing savings that will help offset facility operation costs."

Celina Mayor Jeff Hazel said the award is well-deserved.

"I'm extremely pleased with the work that they performed at the plant," Hazel said Tuesday. "I think that they met the challenge of what we were trying to accomplish and I think from a pretreatment standpoint we couldn't ask for really anything better or more advanced that what we have actually got built at the site."

The process has not been online long enough for plant officials to pinpoint a precise costs savings from reduced chemical treatment, Hazel said.

"As they have made tweaks and adjustments to the tanks, they are very pleased with the performance in how it's cleaning the water up before they even have to treat it," he said.

The project is one of 195 entries this year representing engineering excellence from throughout the world, according to the release. A national 27-member panel of environmental leaders and experts in government, media and academics served as judges.

A new block building covering slightly more than 6,000 square feet was constructed and attached to the clarifier building at the plant. Four aluminum dissolved air flotation units sit inside the building.

The DAF technology allows for incoming raw water particles from the lake to rise to the surface and be scraped away The particles then move to a new bioreactor consisting of four mixing cells that reduce their toxicity before they are pumped to the city's three sludge lagoons on U.S. 127.

Officials believe this new treatment process will pull out as much as 95% of the solids in the earliest stage of the treatment process. The more efficient DAF process should allow city officials to reduce costly chemicals and additives.

The overall project was paid for with an an $8 million Ohio Environmental Protection Agency Drinking Water Solutions Grant and money in the water system reserve fund.

The grant was awarded to Celina in 2016 to relocate its water treatment facility, partner with another political subdivision to access water sources, establish pipelines to access suitable water resources or to treat drinking water.

Hazel in 2018 revealed that Celina would continue to draw its drinking water from Grand Lake well into the future after an exhaustive, multiyear search of underground and surface alternatives came up dry.