Ozone-based treatment will add $40M to algae bill

Toledo needs an additional $40 million to fight microscopic algal toxins inside its Collins Park Water Treatment Plant, city council’s utilities and public service committee learned Monday.

A recommendation to install an ozone-based treatment was among a dozen suggestions revealed publicly for the first time by a blue-ribbon panel of experts the city brought in after last August’s algae-induced water crisis.

The city already had budgeted nearly $300 million in improvements when the crisis occurred. It has since quadrupled its ability to neutralize toxins by using potassium permanganate and powdered activated chlorine at a cost of $5.1 million.

But ozone treatment, also called ozonation, remained a future goal for the 74-year-old facility.

Now the panel of outside experts is calling for the treatment process to be augmented with ozone immediately. The technology, if approved, would not be operating until 2017, said Ed Moore, public utilities director.

Mr. Moore and Warren Henry, an engineer the city hired to oversee improvements, said they were pleased by the blue-ribbon panel’s recommendations because many of them, including the one for ozone, support what city engineers have wanted.

One of the other major recommendations calls for having the city proceed with its plan for 40 million gallons a day of redundancy, so that units can be taken offline and improved one at a time without a disruption in service or stress to the system.

Ozone-based treatment wasn’t part of that original expansion project because algae-treatment wasn’t as big of an issue then, according to Mr. Henry, who told The Blade he expects a request for the additional $40 million to go before full council in 45 to 60 days. Offi

Ozone is a gas with three oxygen molecules created by high-voltage electricity. It reverts back to oxygen quickly and is considered harmless. According to the website water-research.net, it is more effective against bacteria and viruses than chlorine, one of the most common disinfectants at water plants.

Microcystis, considered Lake Erie’s most common form of algae, is actually a blue-green form of bacteria. Also called a cyanobacteria, it mimics algae.

The committee spent nearly 90 minutes talking about algae, but didn’t get through many of the report’s 12 recommendations.

Mr. Moore said he is asking for the discussion to resume at next Monday’s committee meeting.

Moore
Moore

The outside panel of experts did not spend much time considering a possible relocation of the intake. It started to consider the possibility of having the city build an auxiliary intake in the swift-moving Detroit River, then decided that was beyond its scope, Mr. Henry said.

Among its recommendations, though, is a proposal for “some type of baffling arrangement around the intake crib [that] could be beneficial in serving as a barrier against algae entering the intake.”

“The baffle would enable water to be drawn toward the intake from a greater depth, and presumably result in lower levels of algal counts and microcystin toxins. The additional planning effort would include an investigation into various commercially available baffling approaches, a conceptual layout, and possibly computer modeling to confirm the pattern of flow,” according to the report.

The recommendations also call for the city to look into “the viability of some type of river bank filtration or infiltration gallery approach providing further protection during HAB [harmful algal bloom] events.”

It called ozone the “best available treatment barrier for algal toxins” in the long term.

“The city should move forward to implement ozone as soon as possible, understanding that the earliest possible time frame would be with the completion of the plant-wide power improvements scheduled for completion in 2017. The panel recommended moving on a parallel path with ozone and construction of the 40 mgd redundant capacity improvements,” the report said.

Among many other recommendations are ones for better training and communications.

The report does not call for an overhaul of the Collins Park Water Treatment Plant or a new plant to replace the 74-year-old facility. Rather, the recommendations support the need for continued investment and modernization of it.

 

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