USA

– Amber Wooten , Project Engineer Carollo Engineers , Inc .

than the chloramine they were using as a primary disinfectant , says Mattingly . “ We tried chlorine but that generates trihalomethanes ( THMs ), which are regulated and we were not sure we could meet those standards - so we ended up thinking about ozone . Then Carollo came up with the recommendation that UV would be the most effective as our primary disinfectant , with an ozone cycle to improve the taste and quality further .”

This will be the first use of UV in Oklahoma to disinfect a large WTP , though the technology has been used elsewhere , notably at New York City , which has the largest potable water UV treatment plant in the world . As Amber Wooten , Project Engineer at Carollo explains : “ As part of the pilot study , we evaluated placing ozone at different points along the water treatment process . We found that ozone was not the best solution for disinfection , but that it offers some other benefits , such as taste and odor reduction . The combination of ozone and UV allowed the City to make the most efficient use of the treatment as well as the most cost-effective way to attain the levels they wanted .” The design is sophisticated . For example , the City had concerns that the introduction of ozone could interact with bromine in the water to form bromates . “ We found that adding a little chloramine upstream of ozone reduces bromate formation .” says Amber . “ The other interesting thing is that we converted the WTP ’ s existing filters to biofilters to further enhance treatment with minimal capital cost . All of these processes work together to deliver the improved water quality

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