City of Regina drinking water has high levels of chlorine byproduct, but don't worry yet ....
They’re a chemical byproduct of chlorine disinfection in drinking water, and they sound scarier than they really are — at least in low levels.
The accepted level, according to Health Canada, is 0.1 parts per million. Regina’s level in 2015 was 0.13. The city’s average over the past 10 years was 0.075.
“We have been running well below the limit in previous years,” said Pat Wilson, city director of water works.
“It is not a health concern at this time. The water is safe.”
University of Regina chemist Scott Murphy agreed the relatively low number is not worth worrying about at this time: If it were 10 or 100 parts per million, then maybe.
Trihalomethanes (THMs) happen as chlorine interacts with natural organics (like carbon) in the water source. The source Buffalo Pound Lake water has had more organics the past few years, said Wilson, due to higher-than-usual runoff and backups from the “fairly stagnant” Moose Jaw River.
The longer the chlorine is in the water, the more byproducts occur.
It will take a while before the average long-term exposure creeps up to worrisome levels, said Wilson. Anyway, the city is working to fix the problem.
One solution is changing the point where chlorine is added into the system: Right now, it’s added at the lake; water then travels to the Buffalo Pound Water Treatment Plant, then to the city. Adding chlorine at the plant would mean less time that chlorine is in the water.
Another solution is changing the disinfection method, which Wilson says would be a fairly large capital investment.
But the ultimate solution is building a new treatment plant, which is being considered.
“(High THMs) certainly is connected” to the need for new infrastructure, said Wilson. “Some of the work that is currently on the long-term plan would resolve this issue.”
According to Health Canada, decades-long exposure to high THMs is linked to increased risk of bladder and colon cancer, as well as increased risk of miscarriage in pregnant women.
“We chlorinate in order to make sure that the water is safe to drink,” said Wilson. “If you don’t chlorinate the water, there’s a very high likelihood that people are going to get sick.”
The City of Regina tested 75 parameters set out by Health Canada. It will continue monthly monitoring of THM levels in the water.
If people are concerned about the levels, Wilson suggested running drinking water through a carbon-filter pitcher.