Simon Fraser University

Researchers focus on water

Feb 09, 2002 , Vol . 23, No. 3

By Candice Martins
SFU researchers are shaping federal policies on a widely used, but environmentally hazardous, water disinfectant.

Tony Farrell, professor of biological sciences, and Chris Kennedy, associate professor of biological sciences, recently evaluated chloramine's toxicity to juvenile coho salmon and Ceriodaphnia (a freshwater invertebrate and fish food source) for Environment Canada.

The study was part of a comprehensive government assessment that led to chloramine's classification as an environmental toxin. Federal officials are now determining risk management policies for the chemical's use.

Chloramine is an efficient and inexpensive disinfectant for drinking water and industry effluent. It is especially useful for treating water distributed over long distances because, unlike chlorine, it evaporates slowly and doesn't require regular replenishments in the distribution system.

Yet despite chloramine's benefits, Farrell warns that the chemical could cause environmental disasters if it contaminated natural aquatic environments. For example, chloramine from ruptured pipes could easily leak into streams, killing fish and other aquatic wildlife. Farrell notes two such accidents occurred in the Lower Mainland when chloramine was used on a trial basis.

"There's always a tradeoff between using disinfectants to generate potable water and at the same time having to protect the environment from accidental releases," says Farrell. "In my view, the use of chloramine is an unacceptable tradeoff in B.C., where sensitive and biologically productive waterways abound."

Farrell and Kennedy are the first to investigate how the combination of chloramine concentration and exposure time affects toxin-sensitive freshwater organisms. Their data prove that low chloramine concentrations, even ones well below those used for disinfecting water, kill sensitive species when exposure lasts longer than several hours or days (as associated with continuous effluent release).

This information will help develop safe-use regulations and emergency response protocols for chloramine.

Farrell, who also contributed to the government's overall assessment of the chemical, is proud that the research will help protect his home environment. "Ultimately, to affect change, you have to do something," he says. "It's everybody's duty to contribute to a quality environment."