The utilities department has switched to free chlorination, which increases the amount of chlorine being used as disinfectant in the water.
The change is temporary though, said Rachel Atz, the city’s water quality coordinator. She’s been dealing with the complaints residents have been hurling at the city, and she said some are under the impression the city made a permanent switch. That isn’t the case.
“This is a temporary maintenance procedure,” she said.
Atz said she hopes the old system will be reinstated by the end of next week, but that will depend on the data.
Some water storage tanks have been out of service, Atz said, and the utilities department is putting them back into service. This causes pressure changes, which can lead to underground pipe breaks.
Those can cause problems, said Mick Harrison, an environmental lawyer. Water venturing through broken pipes could become contaminated, causing headaches and potential sickness.
Reinstating those tanks can also cause a change in the water’s flow of direction, which can stir up iron deposits. This and other general maintenance procedures make it necessary to increase the chlorine, Atz said.
This isn’t the first time the city has made the switch. In the last seven years, this procedure has been used five to six times, Atz said.
“It’s fairly common for us,” she said. “We were kind of surprised by the backlash.”
Some residents have expressed concern about the increased chlorine in their drinking water. Some are just angry that it tastes different. Atz said the most complaints she’s gotten have been about coffee.
Others, like Harrison, are concerned about the long-term effects of increased chlorine.
Chlorine is a “component of a highly toxic compound,” Harrison said. He said he’s concerned about the potential toxic compounds that can be created from chlorine’s presence in drinking water.
Subjecting water to heat — while cooking, for example — may spark reactions that create these compounds, he said. They’re harmful and potentially cancer-causing.
Harrison said the risk of using disinfectants like chlorine can’t be compared to the risk of not disinfecting at all. But he also said increasing the level of chlorine increases health risks.
The city’s water levels are still below the EPA’s recommended amounts, which are based on risk assessment and actual data, Atz said. But Harrison said that doesn’t matter.
“When you’re talking about carcinogenic chemicals” he said, “There’s really no maximum level.”
While the temporary change in the treatment process has sparked discussion about the city’s overall water quality and questions about how the utilities department treats water, Atz said the two issues aren’t related.
Still, she said the city plans to change how it treats water in the future. The utilities service board passed a contract earlier this month to do an engineering study that will explore strategies for reducing disinfectant byproducts — like the dioxins Harrison mentioned. But Atz said the switch to free chlorination is routine.
“Right now, it’s just a normal procedure,” she said.
