By: Mana Sassanpour
There is serious discussion about treating drinking water in Charlottesville with chloramine. AGC wanted to get some background and answers:
Q: How and Why did the idea of introducing chloramines into our water begin?
A: The U.S. Environmental Protection Agency (EPA) wants to reduce the amount of bacteria and other biological contaminants in our water. Our local Rivanna Water and Sewer Authority (RWSA) is tasked with enforcing EPA standards. Currently, the Charlottesville water system uses chlorine to disinfect our water, but there is concern that chlorine is not enough to keep up with EPA standards.
There are other disinfection options, but chloramines are the most cost effective method, and the RWSA wants to start using them by 2014.
Q: How are chlorine and chloramines similar?
A: Both chlorine and chloramines work to disinfect water – they
also both produce toxic byproducts.
Q: What byproducts do chloramines and chlorine produce?
A: Chloramines produce N-Nitrosodimethylamine (NDMA). Among its adverse health affects are: liver tumors and ‘poisoning the liver’. Chloramine is a known carcinogen. Both chlorine and chloramine compounds are known to be toxic to fish and frogs. Treating water chlorine produces trihalomethane (a byproduct of chlorine and organic material), a chemical known to cause cancer and birth defects.
Q: What are the benefits of using chlorine?
A: Unlike chloramines, chlorine can be boiled off in water because it is more unstable. Chlorine also breaks down more quickly than chloramines do, reducing the amount of it that you ingest once the water reaches your tap.
Q: What are some of the negative effects of using Chloramines?
A: These compounds are formed by ammonia (NH3) reacting with a free chlorine in water. Depending on the pH of the water, the resulting chloramine can be one of three products. Only one of these products works as a good disinfectant, creating the additional need to maintain a basic pH for the chemical to function. Furthermore, chloramines are suspected of making water more corrosive and leaching lead from pipes into water. This effect has been seen in the Washington, D.C. area.
Q: Are there any ‘safe’ alternatives?
A: There is Green Chemistry being done to find cleaner and greener alternatives for purifying water. The Institute for Green Oxidation Chemistry at Carnegie Mellon University under the leadership of Professor Terry Collins is working on a low-cost greener alternative using “TAML” catalysts and hydrogen peroxide. TAML catalysts not only disinfect water but also can break down chemical contaminants such as pesticides and pharmaceuticals (which neither of the methods above can do). Read more about the work being done on TAML catalysts here.