About a hundred years ago, the development of pre-chlorination and disinfection of water led to the end of epidemics of waterborne diseases. People in the U.S. with access to treated water no longer had to worry about deadly typhoid and cholera. But disinfection has led to its own set of problems. The EPA has responded over the last few decades, leading to new DBP regulations. So why can’t you pre-chlorinate anymore? Well, in short, you don’t want to do anything that could contribute to the deaths of your customers.
Treatment, TOCs, and DBPs
For decades water plants have been pre-chlorinating their water to keep their equipment running at optimal levels. The process reduces biological slime formation on filters, tanks, and pipes; oxidizes hydrogen sulfide; and helps control zebra mussels. Pre-chlorination is good for the system, but it may not be great for the water consumer.
Though disinfected water via chlorination is one of the greatest public health developments in history, it’s got some serious drawbacks. All untreated water contains total organic compounds. When those TOCs are treated with chlorine, they produce disinfection byproducts like trihalomethanes and haloacetic acids. Those disinfection byproducts are dangerous. They can cause bladder cancer, and they’re suspected of causing reproductive problems. So even though disinfection makes drinking water safe, it also can make it dangerous.
Delaying chlorination of water until as many TOCs as possible are removed will reduce DBPs. Studies have shown reductions of trihalomethanes by as much as 50 percent by moving the point of chlorination. And reductions of DBPs will help keep your plant in compliance with Stage 1 and Stage 2 DBP regulations.
Stage 1 DBP Regulations
When scientists connected the dots between TOCs, DBPs, and cancer, the EPA took notice.
It established the disinfection byproducts regulation known as Stage 1 in 1998. The regulation went into effect in 2002 and 2004, depending on the size of the plant. Stage 1 established new standards and a treatment technique to reduce DBP exposure.
Stage 1 gets specific about amounts of disinfectant and DBPs. The rule lists new maximum residual disinfectant levels for chlorine, chloramines, and chlorine dioxide. Keeping these levels lower minimizes DBP formation. It also lists new maximum contaminant levels for trihalomethanes and haloacetic acids, chlorite, and bromate. It also requires the use of enhanced coagulation and lime softening to remove TOCs. Each plant is provided a monitoring plan and schedule for collecting DBP samples at each location. Stage 1 established maximum level rules and treatment to reduce harmful byproducts in drinking water.
Stage 2 DBP Regulations
About a decade after the EPA started enforcing the Stage 1 rules, it started on the DBP regulations known as Stage 2. Depending on a plant’s size, the latest round of rules went into effect in 2012 or 2013. The Stage 2 rules supplement Stage 1 and increase monitoring and testing requirements.
Stage 2 rules target two kinds of DBPs—haloacetic acids and trihalomethanes. Managers at water systems had to evaluate their plants and identify the spots with the highest DBP concentration. Those locations became the monitoring sites. The EPA requires the system to meet maximum contaminant levels at each of those monitoring sites, called a location running annual average. Previously, systems used annual averages of samples at all the monitoring sites across the system. Stage 2 set up new monitoring for DBPs.
What to Do?
What happens if your plant’s not meeting Stage 1 or Stage 2 requirements? Under Stage 2, each plant must determine if it has exceeded its operational evaluation level. If so, it must review its practices and submit a report to the state identifying actions to mitigate high DBP levels. You’ve already had to eliminate your pre-chlorination that killed slime and mussels. Now what? You should start with a call to ATS Innova.
Ask the Experts
Our experts will investigate your issues, conduct tests, and determine your best course of action for reducing TOCs and, therefore, DBPs.
A water treatment manager called us to evaluate his facility to help meet those strict government requirements and find ways to save money. When we gave him our report, he was a little hesitant to implement the plan because of the cost. Well, he did implement the plan and he never regretted the decision. The result: significant cost savings and compliance. And he doesn’t want his boss to know it was all our idea.
We’ll give you a course of action to get into compliance with Stage 1 and 2 EPA regulations, protect the health of your customers, and eliminate slime and mussels—all without pre-chlorination. Our revolutionary algaecides are highly soluble, low pH algicide/bactericide, and created for use in ponds, lakes, reservoirs, irrigation canals, sedimentation basins, treatment lagoons, and other water systems. We’ve got the solutions you need.
