Two treatment plants needed to reduce their total organic carbon (TOC) levels. They were both located in the same city—Birmingham, Alabama—and treated water from the same general area. But their total organic carbon situations were different, so they each required different solutions.
Water treatment managers around the U.S. are constantly at war with their TOCs, trying to reduce their total organic carbon or remove TOCs altogether. In recent years the EPA has cracked down on water treatment plants to remove total organic carbon from their water. So what exactly are TOCs, and why is it so important to remove them?
What is Total Organic Carbon?
Total organic carbon is organic matter—aka any carbon-based contaminants—in untreated water. It can contain thousands of parts, including macroscopic particles, dissolved macromolecules, colloids, or compounds. Total organic carbon occurs in untreated water, such as lakes and rivers. The TOC in a body of water is impacted by vegetation in the area, the climate, and even treated sewage released into the water. Total organic carbon is generally what naturally occurs in bodies of water, but it also can be affected by human activity.
Why is it a big deal?
When water is purified for drinking, it’s treated with chlorine to kill TOCs. But new research suggests that TOC levels have a direct effect on harmful disinfection byproducts that form during water treatment. DBPs are known to cause bladder cancer and are suspected of causing reproductive problems, including issues during pregnancy. The higher the TOC level in the untreated water, the higher the DBPs in the treated water.
Recently the U.S. EPA has implemented new rules requiring reductions in DBP levels in treated water. The newest regulations, called Stage 2, are expected to prevent about 280 bladder cancer cases per year in the United States, 26 percent of which would have been fatal. The cost savings of this cancer prevention is estimated at between $763 million and $1.5 billion annually. The EPA’s latest rules for DBPs aim to keep water clean and safer.
How can I fix this?
It sounds like an easy formula—reduce DBPs by lowering TOCs. But TOCs are different everywhere, affected by environmental factors like plant life and climate and all human activity in the area. It takes custom testing and chemistry to get the formula right.
The National Water Research Institute conducted studies on the two water treatment plants in Birmingham. The goal was to reduce TOCs, and therefore, DBPs. At the Shades Mountain Filter Plant, results from the study showed that a simple change in coagulant would increase TOC removal. At the Carson Filter Plant, there were many failed trial runs with chemistry changes. Finally, researchers discovered an optimum configuration and dose of ferric that would reduce the TOC levels. Because conditions can vary even in the same city, TOC problems need custom solutions.
Take action now
Total organic carbon leads to DBPs, which lead to bladder cancer and possibly reproductive problems in water drinkers. So reducing total organic carbon in untreated drinking water is a top priority for the EPA and water managers. Generic solutions won’t work for TOC problems, especially when customers’ health is at stake. With a call to ATS Innova, our experts will evaluate your TOC levels, current processes, and determine how to improve.
