ITHACA, N.Y. — Within less than a month of the city phasing chlorine dioxide, a decontaminate, into Ithaca’s water supply, the levels of chlorite tested above the Maximum Contaminant Level on two occasions.
The chlorite tests, which occur daily, were over the allotted 1.0 milligrams per liter on Sept. 3. The chemical tested at 1.1 mg/l during the day shift and 1.03 mg/l in the early afternoon, officials said in a news release.
Charles Baker, chief operator at the City of Ithaca Water Treatment Plant, said elevated levels of chlorite could be the result of adding chlorine dioxide to the water, a process which began in mid-August.
The chlorine dioxide is comprised of three separate chemicals: sodium chlorite, hydrochloric acid, and sodium hypochlorite.
It’s used to oxidize organic material and will reduce the color and taste of Manganese in the water. High levels of Manganese in the Ithaca water system caused issues last summer when tap water started flowing in irregular colors ranging from light yellow to dark brown.
Baker said that around the time of the Sept. 3 test, plant officials were still trying to get a handle on how the chemicals were fed into the system.
“Hopefully we’ve bypassed that and it won’t happen in the future,” he said.
The chemical additions to the water were modified on Sept. 3 and, on that same day, tested at 0.75 mg/l later in the evening. The next day, the chlorite was tested several times and tested at a peak 0.46 mg/l.
Baker said it doesn’t seem likely that there would be negative health effects from the temporary elevated level of chlorite because symptoms usually occur after prolonged exposure to the chemical.
However, the city of Ithaca issued the following warning as a result of the Sept. 3 tests:
You are not required to do anything due to this event. This is not an emergency. If it had been you would have seen notification immediately. However, we are required to inform you of the EPA health effects mandated language concerning chlorite. It is as follows:
Some infants and young children who drink water containing chlorite in excess of the MCL could experience nervous system effects. Similar effects may occur in fetuses of pregnant women who drink water containing chlorite in excess of the MCL. Some people may experience anemia.